The cathode chemistry at the heart of the study, LiNi0.5Co0.2Mn0.3O2, known throughout the industry as NCM523, is one of the most widely used formulations in modern electric vehicle batteries. Its layered crystal structure packs lithium ions between slabs of nickel, cobalt and manganese oxides, a configuration that stores charge efficiently but also makes recycling complicated. Conventional recycling routes typically rely on strong acids and reducing agents to dissolve the entire cathode, producing a leachate that contains lithium mixed with nickel, cobalt and manganese. Separating those metals from one another demands multiple extraction and precipitation steps, each of which consumes chemicals, energy and money. The Jishou team set out to avoid that bottleneck by asking a different question: rather than forcing every metal into solution, could lithium be selectively extracted while the remaining transition metals are upgraded in place into something valuable?

The answer, according to the new study, is yes, and the key reagent is sodium persulfate, a common industrial oxidizer. Persulfate salts are powerful sources of sulfate radicals, and the researchers harnessed that oxidizing power to attack the cathode lattice in a controlled way. When the spent cathode powder was exposed to a sodium persulfate solution under the right conditions, lithium was leached out of the layered oxide with remarkable efficiency, reaching 97.38 percent under the optimized recipe. Just as important, the process was highly selective: lithium accounted for 79.90 percent of the metal recovered relative to the co-leached nickel, cobalt and manganese, meaning the great majority of the transition metals stayed behind in the solid residue rather than contaminating the lithium stream. That selectivity is precisely what conventional hydrometallurgy struggles to achieve without elaborate separation chemistry.

Getting to those numbers required careful optimization of three variables. The team found that a calcination pretreatment at 420 degrees Celsius was ideal, a temperature low enough to keep the energy budget modest but sufficient to modify the cathode structure in ways that favor lithium extraction. The dosage of sodium persulfate was tuned to 1.0 gram per liter, a concentration that provides enough oxidizing capacity to liberate lithium without driving excessive amounts of nickel, cobalt and manganese into solution. The initial pH was set to a neutral 7.0, an unusually mild condition for battery leaching, which typically operates in strongly acidic media. Running the reaction at neutral pH reduces corrosion risks, simplifies wastewater handling and lowers the overall chemical footprint of the process, all of which matter for any realistic industrial deployment.

What happens to the solid residue left behind after lithium removal is where the study makes its most imaginative leap. In most selective leaching schemes, the delithiated cathode is a byproduct to be dealt with later. Here, the researchers showed that the residue transforms directly, inside the same reaction vessel, into a ternary mixed-phase catalyst composed of nickel oxide, cobalt oxide and manganese dioxide in the form of MnOx phases. The delithiation step itself, driven by the persulfate oxidation, restructures the layered oxide into this new composite without any additional synthesis steps. In effect, the process converts the spent cathode’s residual metal content into a functional photocatalytic material as a built-in consequence of the lithium recovery chemistry, eliminating the need for a separate manufacturing chain.

The catalytic performance of this waste-derived material proved impressive. When tested against methylene blue, a standard model dye used to benchmark water-treatment catalysts, the converted product degraded 98.29 percent of the pollutant in an independent persulfate-activation photocatalytic system. Even in the original one-pot configuration, where lithium leaching and pollutant degradation happen side by side, methylene blue removal reached 91.50 percent. The dual functionality means a single batch of spent cathode powder can yield both a recovered lithium stream and an active catalyst, with the reaction medium doing double duty as a leaching bath and a treatment reactor. For municipal or industrial wastewater operators, the prospect of a catalyst sourced from battery scrap that attacks persistent dyes and organic contaminants is an appealing example of circular economy thinking in practice.

To understand why the catalyst works so well, the team dug into the underlying reaction mechanisms, combining radical-trapping experiments with liquid chromatography tandem mass spectrometry to trace the degradation pathways of the dye. Their analysis pointed to two main engines of destruction. First, light absorbed by the mixed metal oxide catalyst generates photogenerated holes, highly oxidizing entities that can directly attack organic molecules and also drive the formation of secondary reactive species. Second, the multivalent nickel, cobalt and manganese ions in the catalyst cycle between different oxidation states, shuttling electrons to and from the persulfate and dissolved oxygen. These redox cycles promote the generation of singlet oxygen and superoxide radicals, two reactive oxygen species that are efficient at breaking down aromatic dye molecules into smaller fragments, ultimately mineralizing them.

The identification of singlet oxygen as a key player is noteworthy because it distinguishes this system from many advanced oxidation processes that rely predominantly on hydroxyl or sulfate radicals. Singlet oxygen is a more selective oxidant, which can be advantageous in complex water matrices where nonselective radicals are quickly quenched by background constituents such as carbonate or natural organic matter. The combination of photogenerated holes with the cooperative Ni, Co and Mn redox chemistry appears to create a balanced reactive environment in which multiple oxidants operate in parallel, giving the catalyst robustness that single-metal systems often lack. The LC-MS/MS analysis of intermediates provided a molecular-level picture of how methylene blue is dismantled step by step, supporting the mechanistic model rather than relying on inference alone.

The broader context makes the work timely. Studies cited by the authors document the rapid growth of the retired electric vehicle battery stream and the regulatory pressure building around battery recycling worldwide, from business-model analyses of the recycling industry to reviews of global sustainability regulations. Pyrometallurgical routes, which melt batteries at high temperature, lose lithium to slag and demand substantial energy. Hydrometallurgical routes recover more metal but generate acidic waste and struggle with selective separation. Approaches that couple advanced oxidation processes with chemical leaching have emerged as a middle path, and the new study pushes that concept further by making the leaching step itself productive, yielding not just purified lithium but a ready-made catalyst from the same operation.

There are, of course, questions that will need answering before a laboratory one-pot process becomes an industrial flowsheet, including how the method handles real, heterogeneous black mass containing binders, conductive carbon and mixed cathode chemistries, and how the catalyst performs over many reuse cycles. But the numbers reported by the Jishou team, near-complete lithium extraction, strong lithium selectivity, and dye degradation above 98 percent by the waste-derived catalyst, demonstrate that the individual pieces of the concept work. If the approach scales, the humble pile of spent cathode powder awaiting recycling could become a feedstock for two products at once: the lithium that future batteries need, and the catalysts that future water treatment plants will use to keep dye-laden effluent out of rivers. It is a vivid illustration of how rethinking a waste stream, atom by atom, can turn an environmental liability into a pair of assets.

Subject of Research: Selective lithium recovery from spent NCM523 lithium-ion battery cathodes and their in-situ conversion into a persulfate-activating photocatalyst for pollutant degradation

Article Title: A one-pot process for selective lithium recovery and in-situ transformation of NCM523 cathodes into a high-performance photocatalyst

Article References: Hu, Y., Liu, Z., Liu, B., Zou, Q., Li, F., Xiang, Y., & Liu, Y. (2026). A one-pot process for selective lithium recovery and in-situ transformation of NCM523 cathodes into a high-performance photocatalyst. Journal of Materials Science. https://doi.org/10.1007/s10853-026-13821-6

Image Credits: AI Generated

DOI: 10.1007/s10853-026-13821-6

Keywords: lithium-ion battery recycling, NCM523 cathode, selective lithium leaching, sodium persulfate, photocatalysis, methylene blue degradation, singlet oxygen, superoxide radicals, transition metal oxides, advanced oxidation processes, waste-to-resource, circular economy

The research, led by Tanongsak Yingnakorn and Sakhob Khumkoa of Suranaree University of Technology with collaborators including Andrew Abbott of the University of Leicester, tackles a gap that has long frustrated the recycling industry. Conventional recycling routes — pyrometallurgy, which smelts batteries at temperatures up to 1,700 degrees Celsius, and hydrometallurgy, which leaches metals with acids — have been studied extensively. But the upstream stage that feeds them, the mechanical shredding and sorting that concentrates the active electrode materials into black mass, has lacked rigorous paired assessments of cost and environmental impact. Without that baseline, engineers designing full recycling flowsheets have been working partly in the dark.

The team’s approach was refreshingly practical. They obtained donated post-consumer waste: a spent 13-kilogram electric vehicle battery module containing sixteen cells with a nickel-manganese-cobalt cathode, and roughly two kilograms of spent mobile phone batteries with lithium cobalt oxide cathodes. Safety came first. The EV module was discharged electrically, from about 28 volts down to below 0.1 volts, using a custom-built resistor bank. The phone cells, too small to wire individually, were immersed for 24 hours in a 10 percent salt solution — effective, but a choice that would later loom large in the environmental accounting. Electron microscopy and X-ray diffraction confirmed the EV cathode was close to the NMC622 composition, while the phone cells carried the classic cobalt-rich chemistry of consumer electronics.

With the batteries stabilized, the researchers fed them through a custom separation line combining three machines: a shredder that reduced everything to fragments under 10 millimeters, a zigzag air classifier that separates materials by density using a serpentine upward airflow, and a circular vibrating screen with a 500-micron mesh. Two processing routes were tested for each battery type, varying the order of screening and air classification. The verdict was clear. For EV modules, the route that screened first, then air-classified twice at motor frequencies of 23 and 55 hertz, recovered 93.28 percent of the available black mass. For phone cells, the analogous route achieved 75.77 percent. The shredded material was processed under a nitrogen purge to prevent reactions of the thermally unstable lithium hexafluorophosphate electrolyte, which can begin degrading below 40 degrees Celsius when exposed to moisture.

The quality of the recovered powder matters as much as the quantity, and here the results were striking. The EV black mass contained about 3.91 percent lithium, 15.02 percent nickel, 6.01 percent manganese, 7.41 percent cobalt and 53.7 percent carbon, with residual aluminum and copper held below 1 weight percent. The phone-derived powder carried 4.32 percent lithium and 30.95 percent cobalt, with 0.72 percent aluminum and 1.01 percent copper. Both comfortably meet commercial trading specifications, such as Fastmarkets’ thresholds of no more than 2 percent aluminum, copper or fluorine. X-ray diffraction showed the cathode crystal structures survived the mechanical journey intact — no phase transformations, no degradation — a critical point for any downstream process hoping to regenerate rather than merely dissolve the material.

Then came the money. The direct processing cost — electricity, nitrogen gas, and for the phone route, salt, water and hazardous waste disposal — came to just $0.11 per kilogram of EV battery input and $0.53 per kilogram for phone cells. Adding depreciation, labor and a 15 percent management overhead brought the loaded costs to $0.31 and $0.73 per kilogram respectively, far below the $2 to $6 per kilogram typical of pilot-scale processes. Against reference black mass prices of $14.22 per kilogram for NMC622 and $14.05 for lithium cobalt oxide, the baseline net profit was $6.89 per kilogram for EV modules and $8.23 for phone cells, assuming free feedstock. Even when the researchers modeled the realistic scenario of buying scrap on the open market — roughly $2.50 to $2.70 per kilogram in Southeast Asia — both routes remained solidly profitable.

A Monte Carlo simulation across five uncertain variables, from metal prices to plant utilization, reinforced the picture. The median net profit under combined uncertainty was $4.97 per kilogram for the EV route and $6.28 for phones, and the probability of the process losing money was 0.2 percent or less. Feedstock acquisition cost emerged as the dominant driver of profitability, dwarfing electricity prices and separation efficiency. The break-even feedstock price averaged $6.59 per kilogram for EV material — meaning current scrap prices would need to more than double before the flowsheet turned unprofitable. Notably, the phone route earned more per kilogram despite its lower separation efficiency, simply because phone batteries pack a higher proportion of active material and metal foil into every gram.

The life cycle assessment told a more nuanced story. Processing one kilogram of battery waste generated just 0.210 kilograms of carbon dioxide equivalent for the EV route and 0.241 for phones — figures dominated almost entirely by electricity consumption. Because Thailand’s grid draws more than 75 percent of its power from gas and coal, location matters enormously: the researchers calculated that moving the same process to a low-carbon grid would cut the global warming potential by 62.8 percent, from 0.210 to 0.078 kilograms of carbon dioxide equivalent per kilogram of input. The phone route’s Achilles heel was the salt-solution discharge step. When waste treatment was included, its carbon footprint jumped to 2.377 kilograms of carbon dioxide equivalent and its freshwater ecotoxicity soared to nearly 17 CTUe, driven by the incineration of contaminated brine. Reusing the discharge solution for additional batches could cut those impacts by 45 to 60 percent.

The authors are candid about the limits. The runs were single batches of 13 and 2 kilograms on a line designed for 100 kilograms per hour; zigzag classifier efficiency is known to degrade at higher solids loadings, so the figures represent a proof of concept rather than validated industrial performance. The two discharge methods differ between feedstocks, complicating direct comparison, and the life cycle inventory assigns no burden to the 5.5 to 8.3 percent of material lost to dust, volatilized electrolyte and incomplete retrieval — a conservative omission, since that fraction may contain hazardous hydrogen fluoride. Fluorine content could not be quantified with the available instrumentation, and only one cathode chemistry per feedstock was tested.

Still, the study offers something the field has lacked: a fully paired techno-economic and environmental baseline for the same physical flowsheet applied to two structurally distinct battery streams under identical accounting boundaries. Its strategic logic is compelling. Mechanical separation cannot recover individual elements or rebuild cathodes on its own, but as a pre-treatment it delivers a high-grade, low-contamination concentrate at a fraction of the cost of competing routes, feeding hydrometallurgical leaching or direct regeneration with maximum efficiency. As cobalt prices rally and black mass payables hit record highs, and as regulators push extended producer responsibility schemes that pay recyclers to accept spent packs, the humble workhorse of the recycling chain — the shredder, the air classifier, the vibrating screen — may prove to be the quiet engine that makes the battery circular economy finally add up.

Subject of Research: Techno-economic and life cycle assessment of black mass production from spent lithium-ion batteries

Article Title: Baseline techno-economic and life cycle assessment of black mass production

Article References: Yingnakorn, T., Kansomket, C., Longbutsri, C., Scott, S., Patcharawit, T., Yang, J. M., Abbott, A. P., & Khumkoa, S. (2026). Baseline techno-economic and life cycle assessment of black mass production. iScience, 29(10), Article 117729. https://doi.org/10.1016/j.isci.2026.117729

Image Credits: AI Generated

DOI: 10.1016/j.isci.2026.117729

Keywords: lithium-ion battery recycling, black mass, electric vehicles, techno-economic analysis, life cycle assessment, hydrometallurgy, NMC cathode, mechanical separation, circular economy, critical metals, battery discharge, carbon footprint

The team, led by Eric M. Garcia at the Federal University of São João del-Rei, focused on the oxygen evolution reaction, or OER, the half of water electrolysis that has long been the technology’s Achilles heel. While hydrogen gas bubbles off the cathode with relative ease, the anode must tear four electrons away from two water molecules to release one molecule of oxygen, and that multi-step process is kinetically sluggish. Electrolyzers must therefore push the anode several hundred millivolts beyond the thermodynamic requirement, an excess called overpotential that is paid for directly in electricity. Because roughly a million tons of lithium-ion batteries are expected to reach end-of-life by 2030, the researchers saw an opportunity to attack two problems at once: recovering cobalt from a growing mountain of electronic waste and using it to lower the cost of green hydrogen production.

The recycling chemistry begins with a battery dismantled by hand, its cathode material gently scraped from the aluminum foil current collector. After a thermal treatment at 400 degrees Celsius and a thorough washing to remove residual electrolyte, 5.3 grams of recovered active material were leached in 3.0 molar sulfuric acid at 100 degrees Celsius in the presence of 1.0 molar hydrogen peroxide. The peroxide plays a crucial chemical role: cobalt in lithium cobalt oxide sits in the +3 oxidation state, which dissolves poorly, but the reducing agent converts it to the far more soluble Co2+ species. Atomic absorption spectroscopy of the resulting leachate showed a cobalt concentration of 0.054 moles per liter, corresponding to about 3.18 grams of cobalt recovered from a theoretical content of roughly 3.19 grams, an apparent leaching efficiency of approximately 99.7 percent.

With the cobalt in solution, the researchers then raised the pH to 10 by slowly adding potassium hydroxide, precipitating cobalt hydroxide with a gravimetrically determined yield of about 98 percent. X-ray diffraction identified the product as predominantly the hexagonal brucite-like beta phase of Co(OH)2, in which charge-neutral layers of octahedrally coordinated Co2+ ions are stacked through hydrogen bonding. Applying the Scherrer equation to five diffraction peaks gave apparent crystallite sizes between roughly 5 and 10 nanometers, averaging 7.5 nanometers, a small domain size that typically favors catalytic activity by maximizing exposed surface. Infrared spectroscopy added nuance: broad hydroxyl stretching bands and the absence of the sharp 3645 per centimeter feature characteristic of well-ordered beta-phase material pointed to local structural disorder and hydration, likely influenced by residual sulfate species carried over from the acid leaching step, which energy-dispersive X-ray spectroscopy confirmed as trace sulfur alongside potassium from the precipitant.

Rather than coating this powder onto a conventional substrate, the team pressed it directly into the body of an electrode. Graphite powder was mixed with the recycled cobalt hydroxide at loadings ranging from 5 to 80 percent by weight, dispersed in ethanol, ultrasonicated for two hours and dried. The powder was then blended into molten paraffin wax at 80 degrees Celsius and compacted under ten tons of uniaxial pressure into a self-supported cylindrical pellet of two square centimeters. The paraffin serves as a hydrophobic binder that gives the pellet mechanical cohesion, while the graphite provides electrical percolation throughout the bulk. The approach deliberately avoids polymer binders such as Nafion and skips film-deposition steps entirely, meaning the catalyst is distributed through the electrode volume rather than confined to a thin surface layer.

Cyclic voltammetry screening revealed a clear optimum at 40 percent cobalt hydroxide, where the current density at 0.6 volts versus Ag/AgCl peaked before declining at higher loadings. The researchers attribute this maximum to a trade-off between catalytic content and conductivity: too much insulating hydroxide disrupts the graphite network through which electrons must travel, and the hydrophobic paraffin matrix already partially restricts electrolyte penetration to particles buried deep in the composite. The voltammograms also displayed a distinctive anodic process beginning near 0.2 volts, matched by a cathodic peak on the reverse scan, corresponding to the reversible oxidation of Co(OH)2 to cobalt oxyhydroxide, CoOOH. This transformation is widely regarded as the activation step in cobalt-based oxygen evolution catalysis, because the oxyhydroxide phase is more conductive and hosts the active sites where hydroxide ions are adsorbed and oxidized.

Quantitatively, the optimized electrode delivered a current density of 10 milliamperes per square centimeter at an overpotential of approximately 310 millivolts in 1.0 molar potassium hydroxide, with a Tafel slope of 75 millivolts per decade. Both figures compare favorably with literature benchmarks: the overpotential is lower than values reported for nickel phosphide on glassy carbon at 390 millivolts, carbon-supported NiCo nanospheres at 330 millivolts, and cobalt hydroxide on glassy carbon electrodes at 414 millivolts, though it does not match the 236 millivolts achieved by a sophisticated NiFe alloy nanotube catalyst. For an electrode whose active ingredient was pulled from a dead mobile phone and bound in candle wax, the performance is striking. The researchers also measured a reaction order of 0.87 with respect to hydroxide ions by varying the KOH concentration from 0.1 to 6.0 molar, a near-unity value indicating that hydroxide adsorption participates directly in the rate-determining step, consistent with the classical Bockris-Otagawa mechanism in which an adsorbed hydroxyl intermediate reacts with a second hydroxide ion to form a peroxide-like species before oxygen release.

Interface diagnostics reinforced the picture. Double-layer capacitance, a proxy for the electrochemically accessible surface area, rose from 1.69 to 14.2 microfarads per square centimeter upon incorporating the recycled hydroxide, an 8.4-fold increase. Polarization resistance, measured near the equilibrium potential, fell from about 11.4 to 3.15 kiloohm square centimeters, a 72 percent reduction. Most importantly for any practical device, the electrode held a current density close to 10 milliamperes per square centimeter for 180 hours of continuous operation at the 310 millivolt overpotential, with a slight upward drift in current that the authors interpret as progressive electrochemical activation of the cobalt surface under anodic polarization.

The authors are careful about the limits of their evidence. They did not measure Faradaic efficiency for oxygen, perform post-mortem microscopy or spectroscopy, or run electrochemical impedance spectroscopy, so the long-term test demonstrates operational stability of the current rather than proving that the electrode’s structure survived intact. They likewise note that definitive identification of the CoOOH-like active phase would require operando spectroscopy, since cobalt surfaces are known to reconstruct substantially under oxygen-evolving conditions, changing oxidation state and coordination as they work. Trace impurities below the detection limits of their analytical methods also cannot be excluded.

Even with those caveats, the study offers a compelling template for a circular hydrogen economy. It demonstrates that a battery destined for the shredder can pass through a single acid leach and a single precipitation step and emerge as a competitive water-oxidation anode, without phase engineering, nanostructure synthesis or noble metals. As electrolyzer deployments scale alongside renewable power, and as the first great wave of lithium-ion batteries reaches retirement, routes like this one suggest that yesterday’s phones could help supply the electrodes that split tomorrow’s water.

Subject of Research: Recycling cobalt from spent lithium-ion battery cathodes into low-cost electrodes for the oxygen evolution reaction in alkaline water electrolysis

Article Title: Recycled Co(OH)₂ from spent LiCoO₂ cathodes as a low-cost graphite-based composite electrode for the oxygen evolution reaction

Article References: Garcia, E. M., Taroco, H. A., Melo, J. O. F., & Taroco, C. G. (2026). Recycled Co(OH)₂ from spent LiCoO₂ cathodes as a low-cost graphite-based composite electrode for the oxygen evolution reaction. Ionics. https://doi.org/10.1007/s11581-026-07540-w

Image Credits: AI Generated

DOI: 10.1007/s11581-026-07540-w

Keywords: lithium-ion battery recycling, cobalt hydroxide, oxygen evolution reaction, electrocatalysis, water electrolysis, green hydrogen, LiCoO2 cathode, graphite composite electrode, cobalt recovery, Tafel analysis, alkaline medium, circular economy

The material at the heart of the work is a lithium manganese oxide cathode with the formula Li1.27Mn1.73O4, a composition typical of spent lithium-ion batteries from the lithium-manganese-oxide family. Instead of dismantling the chemistry and rebuilding the catalyst from purified metal salts — the conventional, energy-hungry approach — the team treated the spent cathode powder itself as the precursor. After removing the residual lithium using a deep eutectic solvent system based on choline chloride and lactic acid, they were left with a manganese-rich oxide framework ready to be activated. This lithium-extraction step proved critical, because the removal of lithium ions from the host lattice destabilizes the crystal structure and opens the door to defect formation on a scale that ordinary synthesis routes rarely achieve.

The second ingredient in the recipe is the heating method. Rather than ramping up a muffle furnace over hours, the researchers employed flash Joule heating, a technique in which a large electrical current is passed directly through the sample, generating intense heat within the material itself in seconds. The team systematically varied the applied current, producing a series of catalysts labeled FMn-aA, where the current ranged up to 25 amperes. For comparison, they also prepared catalysts from the same battery-derived material using conventional muffle-furnace calcination, and from analytical-grade metal salts processed both ways. This four-way comparison allowed them to isolate the individual and combined effects of the precursor source and the heating regime.

The results were striking. The optimized catalyst, designated FMn-25A, achieved more than 90 percent conversion of benzene at only 208 degrees Celsius. In the catalytic oxidation of VOCs, the temperature at which 90 percent of the pollutant is converted — known as T90 — is a key benchmark, because lower operating temperatures translate directly into lower energy costs and reduced risk of unwanted byproduct formation. Manganese oxides are well known catalysts for this chemistry, but reaching such low light-off temperatures typically requires careful doping, composite formation or noble metal promotion. Here, the researchers obtained the performance simply by choosing a waste-derived precursor and heating it in the right way.

The reason for the enhanced activity lies in the defect chemistry of the material. Detailed characterization combining X-ray diffraction, electron microscopy, X-ray photoelectron spectroscopy, hydrogen temperature-programmed reduction, oxygen temperature-programmed desorption and electron paramagnetic resonance showed that flash Joule heating combined with lithium-ion removal generated an unusually high density of oxygen vacancies — atomic-scale holes in the oxide lattice where an oxygen atom is missing. These vacancies are not passive imperfections. They are chemically active sites that change the electronic environment of neighboring manganese atoms, making the lattice easier to reduce and reoxidize, and they create anchoring points where gas-phase oxygen can adsorb and be converted into reactive oxygen species.

To trace exactly how benzene is destroyed on these surfaces, the team turned to in-situ diffuse reflectance infrared Fourier transform spectroscopy, or DRIFTS. This technique monitors the chemical species present on a catalyst surface while the actual reaction is running. The spectra revealed that the abundant oxygen vacancies promoted the formation of active oxygen species, which then attacked the benzene ring and its partially oxidized intermediates, accelerating the entire oxidation cascade toward complete conversion to carbon dioxide and water. In essence, the vacancies act as continuous suppliers of the reactive oxygen that drives the chemistry, explaining why the defect-rich battery-derived catalysts outperformed their conventionally prepared counterparts, including the CMn-MS sample made from metal salts in a muffle furnace and the salt-derived catalyst heated by flash Joule heating.

The study also underscores a broader lesson about how synthesis conditions shape catalytic materials. Conventional furnace calcination proceeds slowly and at relatively moderate temperatures, allowing the oxide lattice to relax into well-ordered, defect-poor configurations. Flash Joule heating, by contrast, delivers an extreme thermal shock followed by rapid cooling, freezing in a metastable, defect-rich structure. When applied to a lithium-depleted battery cathode — a lattice already destabilized by the extraction of lithium ions — this thermal shock produces exactly the kind of oxygen-deficient, highly reducible surface that low-temperature oxidation catalysis demands. The finding aligns with a growing body of literature on rapid Joule heating for catalyst preparation, which has shown that ultrafast thermal processing can create single-atom sites, defective graphenes and nanostructured electrocatalysts that are difficult or impossible to obtain through conventional routes.

The environmental logic of the approach is twofold. On the waste side, recycling strategies for spent lithium-ion batteries have so far concentrated on recovering lithium, cobalt and nickel from high-value ternary cathodes, while manganese-based cathodes have attracted less commercial attention and often end up in lower-value applications or landfill. Converting this material directly into environmental catalysts gives it a productive second life without demanding the purity levels required for new battery manufacturing. Earlier work by the same research group and others has already demonstrated that spent battery materials can serve as precursors for ammonia-selective catalytic reduction catalysts and for catalysts that simultaneously remove nitrogen oxides and VOCs. The present study extends that concept to lithium manganese oxide chemistry and, crucially, combines it with ultrafast electrified heating rather than energy-intensive furnace treatment.

On the pollution side, catalytic oxidation is one of the most effective technologies for destroying VOC emissions, but its industrial adoption has been constrained by the high temperatures — often above 300 degrees Celsius — that conventional catalysts require to achieve complete conversion. Every hundred degrees saved is a meaningful cut in operating energy and cost, particularly for dilute emission streams from painting, printing, petrochemical and smelting operations, sectors that are significant VOC sources and the focus of tightening regulation. A catalyst that reaches 90 percent benzene conversion at 208 degrees Celsius, made from waste rather than fresh chemicals and activated without prolonged furnace heating, addresses the economic and sustainability dimensions of the problem simultaneously. The authors describe the work as a sustainable strategy for green industrial VOC abatement, and the research was supported by China’s National Science and Technology Major Project on regional environmental improvement in the Beijing-Tianjin-Hebei area.

Significant steps remain before the concept reaches industrial deployment. Real emission streams contain water vapor, sulfur compounds and mixtures of VOCs that can poison or deactivate catalysts, and the long-term stability of a defect-rich structure under continuous operation must be demonstrated. Scaling flash Joule heating from laboratory powder samples to the throughput of a working air-cleaning unit is another engineering challenge, although the process is inherently fast and electrically driven, which favors energy efficiency and compatibility with renewable power. Nevertheless, the study offers a compelling proof of principle: the defective, highly reactive materials that catalyst designers usually struggle to engineer can emerge naturally — and almost instantly — from the wreckage of yesterday’s batteries. In turning one environmental liability into the cure for another, the work captures the kind of cross-cutting chemistry that may define the next generation of sustainable pollution control.

Subject of Research: Flash Joule heating fabrication of defect-rich manganese oxide catalysts from spent lithium-ion battery cathodes for low-temperature VOC oxidation

Article Title: Flash Joule Heating–Driven Fabrication of Defect-Rich Catalysts Derived from Spent Li1.27Mn1.73O4 Batteries for Low-Temperature VOCs Oxidation

Article References: Wang, X., Zheng, Y., Guo, H. Y., Duan, X. H., Gong, C., & Xue, G. (2026). Flash Joule Heating–Driven Fabrication of Defect-Rich Catalysts Derived from Spent Li1.27Mn1.73O4 Batteries for Low-Temperature VOCs Oxidation. Catalysis Letters, 156(10), Article 283. https://doi.org/10.1007/s10562-026-05527-w

Image Credits: AI Generated

DOI: 10.1007/s10562-026-05527-w

Keywords: flash Joule heating, oxygen vacancies, spent lithium-ion batteries, benzene catalytic oxidation, manganese oxides, volatile organic compounds, low-temperature catalysis, lithium-ion removal, deep eutectic solvents, DRIFTS, catalyst recycling, VOC abatement

The scale of the dye problem is enormous. More than 100,000 commercial dyes exist worldwide, with annual production exceeding 700,000 tons, and the textile industry alone consumes over 10,000 tons each year. Roughly 100 tons of dye are estimated to enter aquatic environments annually, where they block sunlight, suppress photosynthesis, and poison aquatic organisms. Methylene blue, the cationic dye used as a model contaminant in this work, is toxic, poorly biodegradable, and notoriously difficult to remove with conventional treatment. Adsorption, the process by which dye molecules stick to a solid surface, remains one of the most practical remediation strategies, provided the adsorbent is cheap, effective, and reusable.

That is precisely where dead batteries come in. Led by Eric M. Garcia of the Federal University of São João del-Rei, the team disassembled commercial cellphone batteries and extracted the graphite-rich anode material. Rather than applying the chemical activation or high-temperature treatment that most high-performance adsorbents require, the researchers simply washed the recovered carbon with 1.0 mol per liter hydrochloric acid for two hours to strip away surface metal contaminants. X-ray diffraction confirmed that the characteristic graphitic peak at 2θ ≈ 26.5° remained intact after purification, while peaks belonging to the copper current collector vanished, indicating that the metal had been removed without damaging the crystalline carbon framework.

Atomic absorption spectroscopy quantified how well the washing step decontaminated the material. Cobalt levels in water contacting the graphite plummeted from 14 milligrams per liter to 0.01, and lithium fell from 17 to 0.02 milligrams per liter, while nickel and manganese were present only in trace amounts throughout. The authors caution that residual metal content in the solid phase was not directly measured, but the aqueous leaching data suggest the purified carbon is substantially safer for environmental use. Fourier-transform infrared spectroscopy added a crucial insight: the anode surface is not pristine graphite but carries oxygen-containing functional groups, carboxylates, carbonyls, hydroxyls, and residues from electrolyte decomposition, and these surface chemistry features turn out to be the secret of its adsorption behavior.

Adsorption tests, run with dye concentrations of 10 to 100 milligrams per liter, an adsorbent dose of 1 gram per liter, and a 24-hour equilibration period, revealed a strong dependence on pH. Performance was poor under acidic conditions, where protonation of the surface and competition from hydrogen ions limit available binding sites, and reached a maximum at pH 10. The explanation lies in acid–base equilibria: at alkaline pH, surface carboxylic and hydroxyl groups deprotonate, generating negatively charged sites that electrostatically attract the positively charged methylene blue molecules. A Langmuir maximum capacity of 7.25 milligrams per gram, with a correlation coefficient of 0.998, described the monolayer adsorption, and the Freundlich exponent remained above one at every pH tested, confirming that adsorption stays favorable even as surface heterogeneity increases.

Thermodynamic analysis between 298 and 318 kelvin painted a picture of a gentle, physical process. The enthalpy change of −6.64 ± 0.47 kilojoules per mole sits far below the threshold typically associated with chemisorption, which exceeds 80 kilojoules per mole, while Gibbs free energy values of roughly −13 to −15 kilojoules per mole confirmed that adsorption is spontaneous. Intriguingly, the entropy change was positive, +23.4 ± 1.6 joules per mole per kelvin, suggesting that the process is driven by the release of ordered water molecules from the adsorbent surface and the dye’s hydration shell. In short, methylene blue clings to the recycled graphite through weak, reversible interactions, electrostatic attraction dominating under alkaline conditions, with π–π stacking between the dye’s aromatic rings and the graphitic domains providing a secondary assist across the whole pH range.

Kinetic measurements reinforced the electrostatic story. The pseudo-first-order rate constant climbed from 0.0202 per minute at pH 2 to 0.100 per minute at pH 10, and the pseudo-second-order constant rose fivefold over the same range, meaning adsorption is dramatically faster in alkaline water. The team also applied a generalized near-equilibrium model that unifies pseudo-first-order, pseudo-second-order, and Elovich kinetics through a coverage-dependent rate coefficient. The fitted heterogeneity parameter came out near 10⁻⁶ under all conditions, collapsing the model to a pure monoexponential relaxation identical in form to pseudo-first-order behavior. This gave the authors a physically meaningful criterion, rather than a statistical one, for classifying the kinetic regime, an approach they argue should be adopted more widely in adsorption research.

Perhaps the most commercially persuasive result is durability. After regenerating the material with dilute hydrochloric acid and drying it at 100 degrees Celsius, the researchers ran seven consecutive adsorption–desorption cycles, and the adsorbent retained more than 90 percent of its original efficiency. This resilience is exactly what one expects from physisorption: because the dye is held by weak, reversible forces rather than irreversible chemical bonds, it can be washed off without destroying the surface. The slight decline over successive cycles is attributed to partial blockage of active sites or incomplete desorption of strongly bound molecules, but the graphitic framework itself appears to survive repeated use essentially unchanged.

Comparisons with the wider literature highlight what makes this approach distinctive. Materials such as graphene oxide can achieve far higher capacities, but producing them demands concentrated acids, strong oxidizers, and controlled thermal processing, which inflate both cost and environmental footprint. The recycled anode carbon delivers a moderate capacity through acid washing alone, placing it alongside waste-derived biochars and mineral adsorbents while requiring almost no processing energy. In a circular economy framing, the anode graphite, which makes up a substantial fraction of battery mass and is usually downcycled or burned, becomes a functional water-treatment material instead of a liability.

The timing is significant. With electric vehicle production in China projected to reach roughly 15 million units per year by 2030, global lithium-ion battery waste could hit 11 million tons by 2030 and approach 900 million tons by 2048. Conventional recycling focuses on valuable cathode metals through energy-intensive hydrometallurgical and pyrometallurgical routes, often leaving the carbonaceous fraction behind. The authors acknowledge that questions remain, including tests in real wastewater, full textural characterization, leaching and toxicity studies, and life-cycle assessment, but the core demonstration stands: a material recovered from the trash, treated with nothing more exotic than dilute acid, can repeatedly pull a stubborn industrial pollutant out of water. As battery waste mounts worldwide, turning dead anodes into working adsorbents may prove one of the simplest and most elegant forms of double-duty recycling yet devised.

Subject of Research: Reusing graphitic carbon from spent lithium-ion battery anodes as a low-cost adsorbent for methylene blue dye removal in wastewater treatment

Article Title: Carbon recovered from lithium ion batteries for methylene blue adsorption and environmental remediation

Article References: Garcia, E. M., Taroco, H. A., & Melo, J. O. F. (2026). Carbon recovered from lithium ion batteries for methylene blue adsorption and environmental remediation. Discover Industrial Chemistry and Materials, 1(1), Article 10. https://doi.org/10.1007/s44508-026-00013-y

Image Credits: AI Generated

DOI: 10.1007/s44508-026-00013-y

Keywords: lithium-ion battery recycling, graphitic carbon, methylene blue, adsorption, wastewater treatment, dye removal, water purification, circular economy, physisorption, battery waste, environmental remediation, reusable adsorbent

The significance of the work lies in its approach, known as direct regeneration. Conventional recycling of lithium-ion batteries typically falls into two camps: pyrometallurgy, in which entire cells are smelted at extreme temperatures to yield a mixed metal alloy, and hydrometallurgy, in which cathode powders are dissolved in acids and the constituent metals are precipitated back out as salts. Both approaches destroy the carefully engineered crystal structure of the cathode and require substantial downstream processing to rebuild a battery-grade compound from scratch. Direct regeneration, by contrast, aims to heal the spent cathode in place, replenishing lost lithium and repairing structural damage while retaining the original particles, their morphology and their composition. Because the energy and chemicals invested in making the original cathode are largely preserved, the method promises lower cost, lower emissions and far less material loss.

The research team focused on NMC 532, a layered oxide cathode in which nickel, manganese and cobalt are combined in a 5:3:2 ratio. This composition is a mainstay of the electric vehicle industry because it balances high energy density with good thermal stability and moderate cost. During years of charge and discharge cycling, however, an NMC cathode suffers from a cascade of degradation mechanisms. Lithium is progressively extracted and only partially returned, leaving the material in a lithium-deficient state. The layered crystal structure, which depends on orderly planes of lithium ions to remain stable, begins to collapse as transition metals migrate into the vacated lithium sites. Surface impurities accumulate, including lithium carbonates and hydroxides formed through reactions with electrolyte and moisture, while microcracks open within the particles themselves. The result is a cathode that no longer conducts lithium ions and electrons efficiently and delivers steadily less capacity.

The regeneration procedure developed by Sharma and her co-workers addresses these failures in a sequence of deliberate steps. First, the recovered cathode material undergoes selective impurity removal, stripping away the parasitic surface compounds that would otherwise interfere with electrochemical performance. Next comes controlled relithiation, in which lithium is resupplied to the depleted crystal lattice in carefully metered quantities, restoring the stoichiometric balance that the layered structure requires. Finally, a moderate thermal treatment consolidates the repair, allowing lithium ions to diffuse into their proper interlayer positions and encouraging displaced transition metals to return to their original sites within the oxide framework. The word moderate is important here: unlike processes that demand furnace temperatures well above a thousand degrees, this treatment operates with restrained energy input, keeping the overall energy budget of the process down to roughly 39 kilowatt-hours per kilogram of recovered material.

That energy figure, the authors emphasise, positions the method as a practical and cost-efficient alternative to conventional regeneration chemistry, which can consume far more reagents and power. Minimising chemical usage was an explicit design goal. In hydrometallurgical flowsheets, large volumes of acid, base and precipitating agents are required, generating secondary waste streams that must themselves be treated. By contrast, the thermochemical route reported here uses comparatively little chemistry, relying instead on controlled thermal and compositional manipulation to accomplish the repair. In an industry where the economics of recycling often teeter on the edge of viability, such reductions in consumable and energy costs could make the difference between a laboratory curiosity and a deployable industrial process.

But a recycling method is only as good as the material it produces, and the team subjected their regenerated NMC 532 to a battery of characterisation tests. Structural analysis confirmed that the layered crystal architecture, the defining feature of a functional cathode, had been successfully restored. Morphological examination showed that the particle integrity, often compromised by cracking in degraded cathodes, had been improved, and compositional measurements verified that the nickel, manganese, cobalt and lithium ratios matched the target specification of the original material. These findings matter because cathode performance is intimately tied to structure: when the layered framework is intact and the lithium sites are properly occupied, lithium ions can shuttle in and out of the particles reversibly over thousands of cycles.

Electrochemical testing provided the decisive verdict. Cathodes fabricated from the regenerated powder delivered an initial discharge capacity of 117 milliampere-hours per gram at a 1 C rate, meaning the material could be fully discharged in one hour, a demanding condition for real-world relevance. More impressive still was the durability: the regenerated cathodes exhibited excellent cycling stability, retaining their capacity over extended operation, and achieved a coulombic efficiency of nearly 99 percent after 150 charge-discharge cycles. Coulombic efficiency, which measures how much charge put into a cell comes back out, is a sensitive indicator of parasitic side reactions; a value approaching 99 percent over 150 cycles signals that the regenerated material is electrochemically clean and structurally sound, not merely superficially revived.

The broader implications extend well beyond a single cathode chemistry. Global sales of electric vehicles continue to climb, and analysts project that hundreds of thousands of tonnes of lithium-ion batteries will reach end of life each year within the coming decade. Cobalt and nickel supplies are geographically concentrated and increasingly expensive, and lithium extraction carries its own environmental burdens. A circular economy for batteries, in which cathode materials are repeatedly regenerated and redeployed rather than mined anew and landfilled after use, would blunt these pressures considerably. Direct regeneration methods such as the one demonstrated here sit at the heart of that vision, because they preserve the highest-value component of the cell in a form close to its finished state, bypassing the costly rebuild-from-elements paradigm of conventional recycling.

Challenges remain before thermochemical regeneration can be scaled from laboratory coin cells to gigafactory volumes. Feedstocks arriving at recycling plants vary widely in chemistry, state of charge and degree of contamination, and a commercial process must handle that heterogeneity robustly. Process control of relithiation and thermal treatment must be precise enough to guarantee consistent quality across tonnes of material rather than grams. Nonetheless, the study offers a compelling proof of concept: with selective impurity removal, controlled relithiation and moderate heating, a spent NMC 532 cathode can be coaxed back to life with minimal chemical input and restrained energy consumption, delivering capacities and cycling stability that validate the approach. If such methods mature, today’s discarded batteries could become tomorrow’s supply of battery-grade cathode, turning one of the clean-energy transition’s thorniest waste problems into a renewable resource stream.

Subject of Research: Direct thermochemical regeneration of spent NMC 532 cathode material from end-of-life lithium-ion batteries

Article Title: Regeneration of NMC cathode active material from discarded li-ion batteries by using thermochemical treatment

Article References: Sharma, Y., Guduru, R. K., Tripathi, B., Sarada, B. V., Tewatia, S., & Rashid, A. (2026). Regeneration of NMC cathode active material from discarded li-ion batteries by using thermochemical treatment. Ionics. https://doi.org/10.1007/s11581-026-07498-9

Image Credits: AI Generated

DOI: 10.1007/s11581-026-07498-9

Keywords: lithium-ion batteries, battery recycling, NMC 532 cathode, direct regeneration, thermochemical treatment, relithiation, cathode materials, circular economy, electric vehicles, energy consumption, electrochemical performance, sustainability

Indigo carmine, chemically known as disodium (2E)-3-oxo-2-(3-oxo-5-sulfonato-1,3-dihydro-2H-indol-2-ylidene)-5-indolinesulfonate, carries a molar mass of 466.36 grams per mole and appears throughout the textile, food, and pharmaceutical industries. Its high water solubility, aromatic structure, and sulfonate functional groups make it both persistent and difficult to strip from industrial effluents. Beyond aesthetic concerns, exposure carries documented risks including biotoxic effects and potential mutagenic and carcinogenic consequences, which makes effective treatment of dye-laden wastewater an environmental priority. Adsorption has long been considered one of the most attractive remediation routes because it is efficient, simple to operate, and inexpensive when low-cost or waste-derived materials are used.

The twist in this study lies in how the researchers deliberately avoided the chemistry that usually dominates when lithium manganese oxide meets this dye. Under acidic conditions, the spinel lattice of LiMn2O4 is redox-active: protons attack the structure, driving delithiation toward lambda-MnO2 and partial disproportionation to MnO, while manganese ions are reduced and the dye is oxidatively destroyed. Previous work, including earlier studies by the same group, exploited this acid-driven redox coupling for oxidative decolorization. But those experiments could not separate adsorption from chemical degradation. By working at pH 7 and pH 11, where manganese redox activity and acid-assisted lattice dissolution are suppressed, the team isolated purely surface-controlled interactions for the first time.

To build the adsorbent, the researchers manually disassembled commercial Nokia BL-4C cellphone batteries, chosen because their cathodes are predominantly LiMn2O4, and separated the cathode tape from the other components. A mild thermal pretreatment at 200 degrees Celsius for five hours in air was applied to volatilize residual organic solvents and electrolyte-derived species while preserving the spinel structure. The authors are careful to note that this step cannot remove polymeric binders such as PVDF, which degrade at higher temperatures, but scanning electron microscopy with energy-dispersive X-ray analysis showed a marked reduction in fluorine and phosphorus signals, consistent with partial cleaning of electrolyte residues such as LiPF6 and its decomposition products.

Characterization confirmed that the recovered material retained its essential identity. X-ray diffraction patterns indexed to the cubic spinel structure of LiMn2O4 in the Fd3-bar space group, matching the JCPDS reference 35-0782, and the pattern was essentially unchanged after dye uptake, showing no new crystalline phases or significant peak shifts. Fourier-transform infrared spectroscopy revealed Mn-O vibrational bands between 500 and 700 reciprocal centimeters characteristic of MnO6 octahedra in mixed Mn3+/Mn4+ valence states. After adsorption, new features appeared in the 900 to 1100 and 1480 to 1650 reciprocal centimeter regions, assigned to C-N and aromatic C=C stretching modes of the dye, alongside a broad 3100 to 3500 band reflecting hydrogen bonding between dye N-H and O-H groups and surface hydroxyl sites.

The quantitative heart of the study is the adsorption isotherm analysis. Using a fixed adsorbent dose of one gram per liter and dye concentrations from 10 to 100 milligrams per liter at 25 degrees Celsius, the Langmuir model fit the pH 7 data exceptionally well, yielding a monolayer capacity of 4.95 milligrams per gram with a correlation coefficient of 0.99. At pH 11, that capacity collapsed to just 0.13 milligrams per gram. Crucially, the Freundlich constant fell by nearly two orders of magnitude and the heterogeneity exponent dropped from 5.40 to 2.68, indicating weaker and less favorable adsorption under alkaline conditions, yet the high correlation coefficients at both pH values showed that the underlying adsorption mechanism remained intact.

The explanation for this dramatic pH dependence came from electrostatics rather than site loss. Zeta potential measurements showed that the recycled powder carries a point of zero charge near pH 3; above it, the surface becomes increasingly negative, ranging from about minus 20 millivolts at pH 7 to minus 60 millivolts at pH 11. Because indigo carmine exists predominantly as a dianionic IC2- species under these conditions, the increasingly negative surface electrostatically repels the dye, excluding it from the adsorption region. Applying a Poisson-Boltzmann-based electrostatic accessibility model in which the apparent Langmuir capacity scales with an exponential Boltzmann factor, the researchers found that matching the experimental capacity ratio required an effective dye charge of approximately minus 2.2, consistent with speciation diagrams showing the dianion accounts for roughly 95 percent of dissolved species even at pH 11.

Thermodynamics painted the picture of a physisorption-dominated process. The enthalpy change of 1.3 plus or minus 0.1 kilojoules per mole is small and positive, indicating a weakly endothermic interaction with no strong chemical bond formation. The entropy change of 100 plus or minus 2 joules per mole per kelvin is large and positive, reflecting the release of structured water molecules and counterions as the dye attaches to the surface. The resulting Gibbs free energy change of minus 28.5 plus or minus 0.6 kilojoules per mole at 298 kelvin confirms spontaneity, and the combination of low enthalpy with high entropy marks adsorption as entropy-driven rather than enthalpy-driven, the classic signature of physical adsorption on heterogeneous oxide surfaces.

Where the material truly distinguishes itself is durability. Although its maximum capacity trails many engineered adsorbents, including functionalized carbon nanotubes, modified graphene oxide composites, and mesoporous metal oxide nanoparticles, the recycled cathode maintained greater than 95 percent removal efficiency across repeated adsorption-regeneration cycles, retaining about 94 percent after 20 adsorption-desorption cycles with only 6 percent total efficiency loss. Regeneration involved simply filtering the powder and soaking it in dilute 0.01 molar hydrochloric acid for 24 hours. The weak physical binding that limits capacity also enables nearly complete dye desorption, minimizing irreversible fouling of active sites. Ultraviolet-visible spectroscopy reinforced the point: after adsorption, the characteristic dye bands at 610, 290, and 250 nanometers remained, merely diminished in intensity, showing the chromophore survived intact and no redox degradation or new degradation products formed.

The broader context makes the approach timely. Global production of spent lithium-ion batteries is projected to exceed 11 million tons by 2030, and cathode materials account for roughly 30 to 40 percent of battery mass while containing high-value metals and structurally robust oxides. Repurposing that waste stream as a functional water-treatment material embodies circular economy principles, converting an environmental liability into an asset. The authors position recycled LiMn2O4 not as a high-capacity engineered sorbent but as a low-cost, waste-derived, structurally stable, and reusable material whose performance hinges on electrostatic accessibility. By coupling isotherm modeling, thermodynamics, zeta potential measurements, and Poisson-Boltzmann theory, the study delivers something rarer than a new adsorbent: a quantitative framework predicting exactly how pH and surface charge govern dye uptake, a framework that could guide the rational deployment of recycled battery oxides in real wastewater treatment wherever near-neutral conditions prevail.

Subject of Research: Adsorptive removal of indigo carmine dye from water using recycled LiMn2O4 cathode material from spent lithium-ion batteries under non-redox conditions.

Article Title: Adsorptive removal of indigo carmine using recycled LiMn2O4 cathode material under non redox conditions

Article References: Garcia, E. M., Dias, T. M., Taroco, H. A., Melo, J. O. F., Mariz, C. S., & de Almeida Rocha, F. (2026). Adsorptive removal of indigo carmine using recycled LiMn2O4 cathode material under non redox conditions. Discover Industrial Chemistry and Materials, 1(1), Article 11. https://doi.org/10.1007/s44508-026-00012-z

Image Credits: AI Generated

DOI: 10.1007/s44508-026-00012-z

Keywords: lithium-ion battery recycling, LiMn2O4, indigo carmine, adsorption, wastewater treatment, physisorption, electrostatic accessibility, zeta potential, Langmuir isotherm, circular economy, dye removal, recycled cathode material

Published in Materials Reports: Solidwaste and Ecomaterials, the study, titled “A systematic review of valuable resource recovery from spent lithium-ion battery cathodes: Technologies, challenges, and future trends,” examines the field through a framework that connects data, mechanisms, and industrial systems. Led by Jianqiu Qin and supervised by Associate Professors Shaoying Li and Liucheng Zhao, the review combines bibliometric analysis with technical, economic, and environmental assessment. Rather than treating recycling as a single chemical operation, the researchers present it as a complete life-cycle system involving collection, sorting, pretreatment, material recovery, environmental management, and the reintegration of recovered products into battery manufacturing.

The review’s bibliometric analysis shows how rapidly this research area has expanded since 2019. China, the United States, and South Korea have emerged as major contributors, reflecting the concentration of battery manufacturing, electric-vehicle production, and energy-storage development in these countries. The focus of research has also evolved. Early studies were strongly oriented toward modifying materials and improving isolated recovery reactions. More recent work increasingly addresses life-cycle management, industrial-scale process integration, carbon emissions, economic feasibility, and the role of recycling within broader energy and manufacturing systems. In other words, the field is moving from the question of whether metals can be recovered to the more difficult question of how they can be recovered sustainably and at commercial scale.

A typical recycling pathway begins with pretreatment. Spent batteries must first be discharged and dismantled safely before components can be separated. Mechanical processes such as crushing, screening, magnetic separation, and gravity separation can concentrate the electrode-rich fraction known as black mass, which contains cathode and anode materials along with conductive additives and binders. Pretreatment is critical because battery packs differ in chemistry, design, state of charge, and degree of degradation. Poorly controlled dismantling can cause short circuits, fires, toxic emissions, or the release of electrolyte compounds. The review also considers echelon, or second-life, utilization, in which batteries that are no longer suitable for electric vehicles may still serve in stationary energy storage before final recycling. Extending battery service life can reduce waste generation, although it also delays material recovery and requires reliable methods for evaluating battery health.

Hydrometallurgy remains one of the most widely studied routes for recovering cathode metals. In this approach, valuable elements are dissolved into an aqueous solution through leaching, often using inorganic acids, organic acids, reducing agents, or other chemical systems. Subsequent purification steps—including solvent extraction, precipitation, ion exchange, and selective crystallization—can separate lithium, cobalt, nickel, and manganese and convert them into compounds suitable for new battery materials. According to the review, hydrometallurgical processes can achieve lithium and cobalt leaching rates above 95 percent under optimized conditions, while also producing relatively high-purity products. Their major weaknesses are the cost and environmental burden of chemical reagents, the generation of acidic or metal-containing wastewater, and the need for complex downstream treatment. A process that recovers metals efficiently but produces large volumes of hazardous liquid waste cannot be considered fully sustainable.

Pyrometallurgy offers a contrasting strategy. Batteries or concentrated black mass are treated at high temperatures, allowing organic components to burn and selected metals to form an alloy or slag. The method is robust, tolerant of mixed feedstocks, and suitable for large-scale continuous operation. It can also simplify pretreatment because some contaminants are destroyed or removed during heating. However, the high temperatures required make pyrometallurgy extremely energy-intensive. Lithium may be lost through volatilization or become trapped in slag, reducing overall resource recovery. The process can also generate substantial greenhouse-gas emissions, particularly when fossil-derived energy is used, and may produce gaseous pollutants that require sophisticated control systems. The researchers therefore describe pyrometallurgy as operationally attractive but environmentally demanding, especially as the battery industry seeks lower-carbon manufacturing and recycling.

Bioleaching represents a greener but slower alternative. Instead of relying primarily on strong chemical reagents, microorganisms or their metabolic products are used to dissolve metals from battery materials. Certain bacteria and fungi can produce organic acids, inorganic acids, or other compounds that promote metal solubilization. Because the process can operate under relatively mild conditions and potentially generate less hazardous waste, bioleaching has drawn attention as an environmentally compatible technology. Its drawbacks are equally clear: metal extraction may take much longer than conventional leaching, microbial activity is sensitive to temperature, pH, nutrient supply, and toxic battery constituents, and maintaining a stable biological system at industrial scale is difficult. These limitations currently restrict bioleaching’s ability to compete with faster chemical routes, although advances in microbial engineering and process control could improve its prospects.

The review identifies direct regeneration as one of the most promising directions for next-generation recycling. Conventional hydrometallurgy and pyrometallurgy generally break cathode materials down into individual elements or salts before those elements are used to manufacture new cathodes. Direct regeneration seeks to preserve and repair the crystal structure of the cathode itself, potentially shortening the process and retaining more of the material’s embedded value. Hydrothermal treatment, relithiation, thermal repair, and electrochemical methods may restore lithium content, reduce structural defects, and recover the performance of degraded cathode powders without fully separating every metal. If successfully scaled, this approach could reduce reagent consumption, energy use, and processing steps. Its central challenge is feedstock variability: cathodes with different chemistries, aging histories, impurities, and compositions cannot always be regenerated through the same recipe.

Emerging solvents could further reshape the recycling landscape. Ionic liquids and deep eutectic solvents have attracted interest because their chemical properties can be tuned for selective dissolution and metal separation. They may enable leaching under milder conditions, reduce volatility, and improve the separation of chemically similar elements. However, their cost, viscosity, recyclability, toxicity profiles, and long-term stability must be assessed before they can be considered truly green alternatives. The researchers emphasize that no single route currently balances recovery efficiency, cost, energy demand, waste generation, and product quality perfectly. A future industrial system is therefore more likely to combine technologies—for example, mechanical pretreatment with selective hydrometallurgy, direct regeneration for suitable cathode streams, and specialized treatment for residues—rather than rely on one universal process.

The study concludes that sustainable battery recycling will require more than laboratory breakthroughs. Digital battery passports could record chemistry, manufacturing history, usage patterns, repair events, and remaining capacity, allowing batteries to be directed toward reuse, echelon applications, or recycling with greater precision. Life-cycle carbon tracking could help manufacturers and regulators compare competing recovery routes using consistent environmental data. Stronger standards for collection, transport, dismantling, worker safety, wastewater management, and recycled-content requirements will also be essential. As electric mobility expands, the success of the battery economy may depend on whether industry can transform end-of-life packs into dependable sources of new materials. The review’s central message is clear: the next phase of lithium-ion battery recycling must be integrated, low-carbon, digitally managed, and designed from the beginning as a closed loop from “end of life” to “new life.”

Subject of Research: Resource recovery and recycling technologies for spent lithium-ion battery cathode materials

Article Title: A systematic review of valuable resource recovery from spent lithium-ion battery cathodes: Technologies, challenges, and future trends

News Publication Date: 29-Jul-2026

Web References: https://doi.org/10.26599/MRSE.2026.9520029

References: Qin, J., Li, S., Zhao, L., et al. “A systematic review of valuable resource recovery from spent lithium-ion battery cathodes: Technologies, challenges, and future trends.” Materials Reports: Solidwaste and Ecomaterials. DOI: 10.26599/MRSE.2026.9520029

Image Credits: Materials Reports: Solidwaste and Ecomaterials, Tsinghua University Press

Keywords: spent lithium-ion batteries, battery recycling, cathode materials, hydrometallurgy, pyrometallurgy, bioleaching, direct regeneration, lithium recovery, cobalt recovery, nickel recovery, circular economy, green technology

The study highlights an innovative approach to separating the critical nickel, cobalt, and manganese (NCM) materials utilized in the cathodes of lithium-ion batteries. These elements are essential for the production of high-performance batteries required for electric vehicles and renewable energy storage systems. As demand for such technologies surges, the importance of resource recovery becomes increasingly clear. This research aims not only to mitigate environmental risks associated with battery waste but also to alleviate the pressure on raw material supplies critical to battery production.

A core element of the study is the development of a novel separation process that employs advanced hydrometallurgical techniques. These methods capitalize on the unique chemical properties of NCM materials, allowing for their efficient extraction from the battery residues. The research team meticulously assessed various chemical agents and operational conditions to optimize the separation efficiency. Their findings suggest that the selected process can achieve high recovery rates of nickel, cobalt, and manganese, highlighting its potential effectiveness in commercial applications.

Moreover, this research underscores the challenges faced in the recycling industry regarding purity and recovery rates. Traditional methods often fall short, resulting in a significant loss of materials and creating economic disincentives for recycling efforts. By enhancing the separation process, Zheng and colleagues hope to pave the way for increased profitability in the recycling sector, incentivizing companies to invest in greener practices.

The escalating demand for electric vehicles and energy storage solutions underscores the necessity of establishing robust recycling protocols. With millions of lithium-ion batteries reaching their end of life each year, the environmental impact of improper disposal is profound. The researchers emphasize that developing efficient recovery methods for battery materials is paramount in reducing landfill waste and conserving natural resources, thus promoting environmental sustainability.

In addition, the study is positioned within the larger context of global initiatives aiming to reduce carbon emissions and promote the use of renewable energy. By recovering valuable materials from discarded batteries, the researchers are contributing to a more sustainable energy ecosystem. The transition to electric mobility and renewable energy storage solutions cannot be fulfilled without addressing the lifecycle of battery materials, making this research timely and relevant.

The implications of this research extend beyond environmental benefits; they also hold significant economic potential. The recovery of nickel, cobalt, and manganese from discarded batteries could lead to reduced dependency on imported raw materials, enhancing national energy security. Recycling operations could stimulate job creation in the green technology sector, further contributing to economic growth while addressing environmental concerns.

Importantly, this work lays the groundwork for future investigations into battery recycling methods, inspiring further academic exploration in the field. With ongoing advancements in material science and engineering, researchers are encouraged to seek innovative solutions to the challenges posed by battery waste. This study serves as a clarion call for collaboration across industries, urging stakeholders to engage in responsible resource management practices.

The publication of these findings is poised to generate interest within both academic circles and the wider community, particularly among policymakers and industry leaders. The compelling evidence supporting the economic and environmental benefits of efficient battery material recovery can serve as a catalyst for legislative action and investment in recycling infrastructure. As awareness of environmental issues rises, public pressure may further drive the adoption of sustainable practices across industries.

In conclusion, the research conducted by Zheng, Chen, Wang, and their team offers a promising glimpse into the future of battery recycling. Their innovative approach to separating valuable materials from discarded lithium-ion batteries not only contributes to environmental sustainability but also holds the potential for significant economic benefits. The importance of this work cannot be overstated as we navigate the challenges of a rapidly changing world where technological advancements must harmonize with ecological preservation. As further studies emerge in this domain, the journey towards a more sustainable and circular battery economy continues to evolve.

In summary, this research signifies a crucial step towards enhancing the efficiency of material recovery from lithium-ion batteries—a step that is not only essential for advancing sustainable technology but also for ensuring the longevity and viability of the electric vehicle and renewable energy sectors.

Subject of Research: Efficient separation of nickel cobalt manganese ternary cathode materials from discarded pouch lithium-ion batteries.

Article Title: Process study for the efficient separation of nickel cobalt manganese ternary cathode materials from discarded pouch lithium-ion batteries.

Article References:

Zheng, B., Chen, M., Wang, W. et al. Process study for the efficient separation of nickel cobalt manganese ternary cathode materials from discarded pouch lithium-ion batteries.
Ionics (2025). https://doi.org/10.1007/s11581-025-06801-4

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s11581-025-06801-4

Keywords: Lithium-ion batteries, recycling, nickel, cobalt, manganese, sustainable technology, materials recovery, circular economy.

China, as the world’s largest EV market, faces immense pressure to secure a consistent and sustainable supply of battery materials. The nation’s explosive growth in EV production and adoption is projected to cause a surge in demand for metals critical to lithium-ion batteries. Traditional mining activities not only face economic and environmental constraints but are also subject to geopolitical volatility. The study underscores the importance of establishing a robust domestic recycling ecosystem to alleviate reliance on virgin material extraction. Battery recycling, the researchers argue, is a pivotal strategy that can both mitigate supply risks and reduce the environmental footprint associated with primary mining.

The research employs comprehensive modeling that integrates technological, economic, and policy dimensions of lithium-ion battery recycling. By analyzing current battery life cycles alongside projected EV deployment rates, the team delineates material flow scenarios extending several decades into the future. This dynamic approach reveals how recovered materials from spent batteries can be reintroduced into the production chain, significantly offsetting the demand for raw resources. The implications are profound: large-scale recycling programs could transform potential shortages into manageable surpluses, ensuring steady material availability as the global push for electrification intensifies.

A critical aspect explored in the study involves the efficiency and scalability of existing recycling technologies. While many processes exist, ranging from pyrometallurgical to hydrometallurgical methods, their ability to recover lithium and other metals at high yield and purity remains a technical challenge. Zhang and colleagues comprehensively assess these technologies, identifying key bottlenecks and opportunities for innovation. Their analysis highlights recent advancements that markedly improve material recovery rates while lowering energy consumption and operational costs, setting the stage for economically viable recycling at scale.

The paper also delves into the policy frameworks necessary to incentivize recycling infrastructure development. China’s national strategies already emphasize green energy and resource security, but the researchers suggest that targeted policies—such as extended producer responsibility (EPR) mandates, subsidies for recycling facilities, and standardized battery designs—could dramatically enhance recycling rates. Harmonizing regulations with technological progress, they argue, will be essential to unlock the full potential of battery circularity and secure China’s leadership in the EV sector.

In addition to safeguarding raw material supplies, the environmental benefits of recycling lithium-ion batteries form a core pillar of the authors’ argument. Mining operations are energy-intensive, generate significant greenhouse gas emissions, and often raise concerns about ecological disruptions and human rights. Recycling, by recapturing valuable metals from spent batteries, mitigates these impacts by curbing the need for new mining activities. The study quantitatively compares the life-cycle environmental footprints of recycled versus virgin materials, confirming that recycling pathways can substantially reduce carbon emissions and resource depletion.

Furthermore, the work underscores the economic ramifications for both manufacturers and consumers. Recycled materials have the potential to stabilize raw material prices, which currently exhibit volatility driven by geopolitical tensions and supply-demand imbalances. This price stability would benefit battery manufacturers by reducing input cost uncertainties, enabling more predictable production planning and potentially lowering the end cost of electric vehicles. For consumers, this could translate to more affordable and accessible EV options, accelerating market penetration and fostering a positive feedback loop in the transition to sustainable transport.

One of the study’s novel contributions is its detailed mapping of the battery recycling supply chain within China. It accounts for variables such as collection logistics, processing capacities, and the anticipated volume of end-of-life batteries. The authors note that while China boasts a strong industrial base capable of supporting recycling activities, the current collection rates of spent batteries remain suboptimal partly due to fragmented channels and limited consumer awareness. Addressing these gaps through education campaigns and streamlined collection incentives is highlighted as a necessary next step to maximize recycling efficacy.

The researchers also emphasize that battery design plays a critical role in the recyclability of lithium-ion cells. As materials and chemistries evolve, standardization becomes increasingly important for optimizing recovery processes. The study advocates for a collaborative approach, where manufacturers, policymakers, and recyclers coordinate on design-for-recycling principles that simplify disassembly and enhance material extraction. This forward-looking perspective aligns with broader circular economy concepts and could lead to disruptions in how batteries are produced and managed throughout their life cycles.

Crucially, the environmental and economic benefits outlined are complemented by social considerations. Improved recycling infrastructure creates new employment opportunities and incentivizes technological innovation within local communities. The transformation from a linear battery production-consumption-disposal model to a circular one fosters sustainable industries and skills development. In regions reliant on mining, recycling may mitigate some adverse social impacts by reducing dependence on extractive activities. Thus, the transition offers a holistic model supporting environmental sustainability, economic resilience, and social well-being concurrently.

Zhang et al.’s analysis also tackles the broader global significance of their findings. Although the research centers on China’s context, the mechanisms and strategies proposed are broadly applicable to other rapidly electrifying markets. The impending global battery waste surge requires coordinated international efforts in technology sharing, policy formulation, and capacity building. The study’s comprehensive scenarios and policy recommendations can serve as a blueprint for countries seeking to integrate recycling into their own EV supply chains effectively.

Looking ahead, the study indicates key areas for future research and technical development. Enhancing lithium recovery rates, reducing processing costs, and scaling pilot recycling projects to industrial levels remain priorities. Furthermore, investigating alternative battery chemistries that balance performance, cost, and recyclability could provide complementary pathways to address resource constraints. Integrating digital tracking systems could also enhance end-of-life battery management, ensuring accurate data collection and incentivizing consumer participation.

In conclusion, this timely research encapsulates a critical dimension of the EV transition often overshadowed by battery performance metrics—the lifecycle environmental and material sustainability of lithium-ion batteries. By demonstrating that recycling can substantially relieve material scarcity risks without compromising economic feasibility or environmental responsibility, Zhang, Xin, Chen, and their team contribute invaluable insights for policymakers, industry stakeholders, and sustainability advocates alike. Their work reaffirms that a sustainable, circular battery economy is not just desirable but necessary for the future of transportation.

As global electrification efforts move from promising concepts to tangible realities, addressing supply chain vulnerabilities becomes paramount. The study’s evidence-based recommendations provide a strategic roadmap for China, offering scalable solutions that could reverberate worldwide. With synthesis of technological innovation, robust policy frameworks, and market incentives, lithium-ion battery recycling emerges not only as an environmental imperative but also as a catalyst for enduring industrial competitiveness and energy security.

Ultimately, this research marks a pivotal contribution to our understanding of how technological and policy integration can reshape resource management in a rapidly evolving sector. Leveraging battery recycling as a cornerstone of sustainable development unlocks pathways to a cleaner, more resilient future—where electric vehicles fulfill their promise without depleting the very materials essential to their operation.

Subject of Research:
Lithium-ion battery recycling as a strategy to mitigate material scarcity amidst rapid electric vehicle adoption in China.

Article Title:
Lithium-ion battery recycling relieves the threat to material scarcity amid China’s electric vehicle ambitions.

Article References:
Zhang, B., Xin, Q., Chen, S. et al. Lithium-ion battery recycling relieves the threat to material scarcity amid China’s electric vehicle ambitions. Nat Commun 16, 6661 (2025). https://doi.org/10.1038/s41467-025-61481-y

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