At the forefront of addressing this challenge, a recent study led by Kwon, Kim, Hyun, and colleagues introduces novel insights into the design of interphase chemistry tailored for rapid lithium plating and stripping. The researchers specifically investigate a series of pyran-based electrolytes, modified by varying substitutional anions, under stringent fast charging protocols. Their work reveals that the nature of the anionic species in the electrolyte critically influences lithium-ion association dynamics, which in turn governs the morphology and stability of lithium deposition during charging.

The fundamental difficulty in fast charging lithium metal batteries lies in managing the formation and evolution of the SEI — a complex, nanoscale composite layer formed at the electrode–electrolyte interface. Traditionally, this interphase comprises a mixture of inorganic and organic decomposition products arising from electrolyte breakdown. While the SEI is essential for passivating the reactive lithium surface, its heterogeneous composition and uncontrolled growth often precipitate the formation of dendrites, short circuits, and capacity fade, especially under accelerated charge rates that amplify ion flux and interfacial reactivity.

This study sheds light on the role of anion chemistry in mediating these processes. The researchers designed electrolytes incorporating weakly lithium-ion associating anions, hypothesizing that such species could suppress the clustering of inorganic components within the SEI. Using comprehensive electrochemical and spectroscopic characterization techniques, they confirmed that these anions indeed facilitate more uniform lithium nucleation and growth. The resulting lithium deposits were denser and more homogenous compared to those formed in electrolytes containing strongly associating anions, which are prone to heterogeneous plating and accelerated degradation.

Crucially, the electrolyte formulations enabled lithium metal batteries to sustain exceptionally fast charging cycles while maintaining remarkable cycling stability. The team achieved charging from 5% to 70% state of charge (SoC) in just 12 minutes at a high current density of 8.4 mA cm⁻² (4C rate), maintaining this performance over 350 repeated cycles. This represents a significant advance over existing lithium metal battery systems, where rapid charging typically results in compromised safety and diminished cycle life due to dendritic lithium growth and unstable interphases.

Further emphasizing the practical impact, the researchers demonstrated high-energy cell designs projecting energy densities upwards of 386 Wh kg⁻¹, coupled with fast charging capabilities reaching 10% to 80% SoC in 17 minutes sustained over 180 cycles. These metrics push the boundaries of battery performance, indicating that with meticulous electrolyte design centered on anionic control, lithium metal batteries can indeed merge high energy with fast chargeability, a feat long sought after in the domain of electric mobility.

From a mechanistic standpoint, the suppression of inorganic species clustering within the SEI under fast charging conditions emerges as a pivotal factor. The weak Li⁺-associating anions appear to modulate solvation structures and interfacial ion transport, mitigating local ionic concentration gradients that otherwise fuel irregular deposition morphologies. By stabilizing the interphase architecture at the nanoscale, these anions enact a form of ‘chemical governance’ that preserves the integrity and uniformity of lithium plating, thereby enhancing both safety and longevity.

The implications of this discovery extend beyond the specific electrolyte chemistries explored. They highlight a broader strategy for electrolyte development—where the focus shifts from merely optimizing ionic conductivity or electrochemical stability to engineering the nuanced interactions between lithium ions and electrolyte constituents to directly control interphase formation. This paradigm could inspire next-generation electrolyte systems tailored not just for lithium metal batteries but also for other emerging metal anode chemistries prone to interfacial instabilities.

Moreover, the rapid charging performance achieved in these systems addresses one of the most significant bottlenecks for consumer adoption of EVs: charging convenience. Current fast charging infrastructure often results in battery degradation or safety concerns due to thermal and electrochemical stresses. By enabling uniform lithium plating at 4C rates, these novel electrolytes promise batteries that can be charged rapidly without sacrificing cycle life—ushering in a new era where EV users could recharge as swiftly as refueling a combustion engine vehicle.

The study also underscores the importance of comprehensive characterization of interphasic properties under real-world operational stresses. Utilizing advanced in situ and ex situ analytical methods, the team correlated microscopic interphase features with macroscopic electrochemical performance. Such multiscale understanding is key to translating laboratory innovations into commercial battery technologies, as it enables targeted improvements and predictive diagnostics.

Nevertheless, challenges remain in the path to commercialization. Scale-up synthesis of specialized pyran-based electrolytes and their integration into full-cell architectures require careful consideration of cost, stability under varying environmental conditions, and compatibility with manufacturing processes. Additionally, long-term safety assessments under diverse cycling regimes will be essential to validate their viability for mass-market deployment.

One of the promising aspects of this approach is its compatibility with existing battery manufacturing infrastructure, as the electrolyte modifications do not necessitate radical changes in electrode design or cell format. This compatibility could accelerate the adoption of high-energy, fast-charging lithium metal batteries once the electrolyte chemistries are optimized for commercial scalability and regulatory compliance.

This breakthrough also sparks exciting prospects for fundamental scientific research. The observed covariance between interphase structure and electrochemical kinetics invites deeper exploration into the physicochemical principles governing metal electrodeposition dynamics. Understanding these interactions at the molecular level could unlock further refinements in electrolyte formulations, potentially achieving even higher charging rates without compromising battery life or safety.

Furthermore, this work may catalyze renewed interest in leveraging organic frameworks such as pyran derivatives for electrolyte design. These molecules offer versatile platforms for functionalization to tune solvation dynamics, ionic association, and interfacial chemistry. Their modularity could enable bespoke electrolyte recipes customized for specific battery chemistries and operating conditions.

In conclusion, the study by Kwon and colleagues represents a landmark achievement in lithium metal battery research. By innovatively harnessing the interplay between anion chemistry and interphase properties, they deliver a compelling solution to the long-standing challenge of fast charging in high-energy batteries. Their approach paves the way for next-generation energy storage technologies that combine rapid rechargeability with extended cycle life, potentially revolutionizing electric transportation and portable power systems.

As global demand for clean and efficient energy storage accelerates, such fundamental advances in battery science are critical. The capability to fast charge lithium metal batteries reliably and repeatedly without compromising safety or performance could redefine expectations for electric vehicles and beyond. While further development and validation remain, this research not only advances the state-of-the-art but also illuminates a promising path forward for the energy storage community.

Ultimately, the convergence of materials chemistry, electrochemical engineering, and analytical science evident in this work exemplifies the multidisciplinary innovation required to overcome complex technological challenges. By elucidating the mechanisms underpinning fast chargeability and interphase stability, this study equips scientists and engineers with new tools and strategies to craft the batteries of tomorrow—faster, safer, and more powerful than ever before.

Subject of Research: Lithium metal batteries and electrolyte interphase design for enhanced fast charging performance.

Article Title: Covariance of interphasic properties and fast chargeability of energy-dense lithium metal batteries.

Article References:
Kwon, H., Kim, S., Hyun, J. et al. Covariance of interphasic properties and fast chargeability of energy-dense lithium metal batteries. Nat Energy (2025). https://doi.org/10.1038/s41560-025-01838-1

Image Credits: AI Generated

Addressing the inherent issues related to lithium metal anodes is vital for harnessing the full potential of LMBs. One of the fundamental strategies being pursued is the modification of electrolytes to better regulate the interfacial inorganic components. Strengthening the solid electrolyte interphase (SEI) is critical, as it protects the lithium metal from detrimental side reactions that degrade battery performance. Researchers are exploring the development of efficient electrolyte additives as an optimal approach, due to their cost-effectiveness and practical application in real-world scenarios.

In a groundbreaking study published in the esteemed journal National Science Review, Professor Yuping Wu and Associate Professor Tao Wang from Southeast University introduced a novel thioether-based electrolyte additive known as 1,3-dithiane. This innovative additive plays a pivotal role in restructuring electrode interfaces through a synergistic mechanism that utilizes three distinct processes. The findings from this research could mark a significant advancement in achieving long-cycle and high-performance lithium metal batteries.

The first mechanism by which 1,3-dithiane operates involves polarity inversion and the suppression of organic components in the SEI. The unique structure of the compound allows for highly acidic hydrogen at the 2-methylene position to react with alkyl lithium, resulting in the formation of a crucial intermediate known as 2-lithio-1,3-dithiane. This chemical transformation plays a vital role in minimizing the formation of unstable organic materials in the SEI. The decomposition of this intermediate results in a sulfur-rich interface on the lithium surface, transforming delicate organics into more stable sulfur-containing inorganic compounds. Concurrently, this additive significantly enhances the resistance of carbonate solvents to nucleophilic attacks, which is an essential improvement for the longevity of battery performance.

The second aspect of 1,3-dithiane’s action on the battery interface is its contribution to kinetic and thermodynamic optimization. By utilizing the preferential adsorption kinetics and redox properties inherent in this thioether compound, the additive helps to create a highly stable and dynamic interface on the electrodes. This enhanced interface fosters the participation of PF₆^– anions in the film formation process. As a result, a robust inorganic-rich interphase with high ionic conductivity is constructed, significantly improving the overall efficiency of the battery’s operation.

Perhaps the most surprising aspect of the research is the additive’s substantial sulfur content, which reaches an impressive 53.5%. This level of sulfur utilization is nearly double that of traditional sulfur additives, allowing for effective interfacial regulation even at low concentrations. Such a breakthrough not only paves the way for advancements in thioether additives but also opens new research avenues and development opportunities in the field of battery technology.

The practical implications of using 1,3-dithiane as an electrolyte additive were showcased in experiments with Li||LiFePO₄ full cells. These cells, utilizing the modified electrolyte, exhibited an extraordinary capacity retention of 83.6% after an impressive 3,300 cycles at a 1C rate. Furthermore, lab-fabricated cells demonstrated an outstanding capacity retention of 93.1% after 150 cycles, highlighting a tenfold extension in overall cycle life. Such remarkable results underline the potential of 1,3-dithiane in enabling long-cycle lithium metal batteries even under quasi-commercial conditions.

Beyond these results, the research represents a low-cost universal strategy for constructing stable interfaces that are rich in inorganic materials. This advancement has the potential to catalyze further developments in LMBs, driving practical improvements in energy storage solutions and expanding the options available for battery manufacturers.

The significance of this research is underscored by the support it received from prominent institutions, including the National Key R&D Program of China, the National Natural Science Foundation of China, the Jiangsu Provincial Key R&D Program, and the Southeast University High-Level Talent Startup Fund. This backing illustrates the importance attributed to ongoing research and innovation in the realm of energy storage and battery technology.

In conclusion, the discovery and implementation of 1,3-dithiane as a thioether-based electrolyte additive represent a monumental stride forward in the quest to develop efficient, long-lasting lithium metal batteries. This additive addresses critical challenges faced by lithium metal anodes, thereby reinforcing their interfaces and significantly improving overall battery performance. As the research community continues to unravel the complexities of battery technology, such innovations will be paramount in ensuring a sustainable and efficient energy future.

Subject of Research: Thioether-based electrolyte additives for lithium metal batteries
Article Title: A Novel Thioether-based Electrolyte Additive for Lithium Metal Batteries
News Publication Date: October 2023
Web References: National Science Review DOI
References: Research funded by National Key R&D Program of China, National Natural Science Foundation of China, Jiangsu Provincial Key R&D Program, Southeast University High-Level Talent Startup Fund.
Image Credits: ©Science China Press

Keywords

Lithium metal batteries, thioether, electrolyte additives, solid electrolyte interphase, energy storage technology, capacity retention, sulfur utilization, battery performance, inorganic-rich interphase, electrode interface.

The researchers began by recognizing that the nucleation of lithium does not occur in isolation but rather within a complex interfacial environment. At the core of this environment are two critical interfaces: the interface between lithium and the electrolyte, specifically the solid–electrolyte interphase (SEI), and the interface between lithium and the substrate upon which lithium deposits. The SEI is a chemically heterogeneous, ion-conductive but electron-insulating layer that forms naturally during battery cycling and strongly influences lithium ion transport at the electrode surface. Meanwhile, the substrate provides nucleation sites and pathways for lithium atoms once they arrive at the electrode surface. Understanding how these two interfaces interact and individually or jointly regulate nucleation was the central focus of the team’s investigation.

To dissect these complex interfacial dynamics, the authors employed a physics-based modeling approach that allowed them to quantify the controlling factors in lithium nucleation across a range of electrolyte and substrate combinations. Their model revealed a bifurcation in nucleation regimes primarily governed by the kinetic properties of lithium ion transport and charge transfer at the SEI as well as lithium adatom mobility on the substrate. In scenarios where ion transport through the SEI and charge transfer kinetics were sluggish, the nucleation process was overwhelmingly controlled by the SEI, rendering the substrate properties effectively irrelevant. Conversely, when the SEI allowed rapid lithium transport and charge transfer, the substrate itself became the dominant factor controlling nucleation.

This substrate-controlled nucleation regime was particularly revealing. It highlighted the critical importance of the speed at which lithium adatoms—individual lithium atoms adsorbed onto the substrate surface—move or diffuse along the substrate. The authors showed that for dense, uniform lithium nucleation to occur, the velocity of lithium adatoms must surpass a certain critical threshold that outpaces the formation of unstable nuclei. In other words, a surface that enables fast lithium adatom migration promotes the growth of stable lithium nuclei while suppressing the formation of dendrites and whiskers that can degrade battery performance.

The study elucidates the dualistic nature of lithium nucleation control, emphasizing that improving battery performance is not solely a matter of optimizing the electrolyte or the substrate independently but requires holistic engineering of both interfaces. For instance, simply enhancing SEI transport without considering substrate characteristics will not guarantee uniform and reversible lithium deposition. Similarly, tuning substrate surface energies and adatom mobilities without ensuring compatible electrolyte transport properties may prove insufficient. This dual control mechanism underscores the complexity of electrochemical interface engineering in lithium metal batteries.

Importantly, the findings offer a conceptual framework for rational design of next-generation battery materials. By mapping out regimes where nucleation is governed by SEI characteristics versus substrate properties, the model guides material scientists in choosing or designing electrolytes and substrates that synergistically promote fast lithium transport and substrate diffusion. The authors specifically point toward the need for electrolyte formulations that form SEIs with high lithium ion conductivity and for substrate surfaces engineered at the atomic scale to facilitate rapid lithium adatom migration.

Moreover, the researchers connected nucleation modes to lithium plating and stripping reversibility, a key metric for battery cycle life and safety. Dense, uniform lithium deposition achieved via fast SEI transport and rapid adatom movement minimizes the formation of isolated lithium “dead zones” and mitigates volumetric changes during cycling. These improvements translate to longer cycle life, higher coulombic efficiency, and reduced risk of battery failure modes such as short-circuiting or capacity loss.

To validate their theoretical insights, the team performed simulations that capture the nucleation kinetics under various interface-controlled conditions. Their results reproduced experimental observations reported in the literature where certain electrolyte–substrate combinations favor dendritic growth, while others promote smooth lithium surfaces. This further bolsters the robustness of their model and provides confidence that their framework can be applied in practical battery design scenarios.

The discovery that the lithium nucleation process can be decoupled into SEI-controlled and substrate-controlled regimes represents a paradigm shift in our understanding of metal anode behavior. It moves beyond the simplistic view that dendrite formation is merely a byproduct of electrolyte instability or substrate roughness alone. Instead, it reveals a nuanced balance where interfacial transport kinetics and surface diffusion dynamics jointly dictate the nanoscale pathways of lithium growth.

Looking forward, this research invites the development of advanced characterization techniques that can probe lithium adatom mobility at electrode surfaces in operando conditions. Such experimental validations would further confirm the predictions made by the model and help transitioning the insights into practical battery systems. Additionally, the principles uncovered here may extend beyond lithium metal batteries, offering lessons for other metal anode systems, such as sodium or magnesium, which face similar nucleation challenges.

The critical take-home message from Hui and co-authors’ study is the necessity of fostering simultaneous fast lithium transport through the SEI and fast lithium adatom movement on the substrate to achieve dense, uniform, and reversible lithium metal deposition. Only by mastering these intertwined interfacial dynamics can the long-standing challenges of lithium metal batteries—dendrite growth, low cycle life, and safety concerns—be effectively addressed.

To propel the field forward, future research should also examine how novel substrate materials such as two-dimensional materials, alloys, or nanostructured frameworks influence adatom mobility. Similarly, electrolyte engineering focusing on additive chemistry to tailor SEI properties will be essential. Combining these approaches in light of this new nucleation framework holds promise for breakthroughs toward practical lithium metal batteries.

In conclusion, the study not only deepens fundamental scientific knowledge of lithium nucleation but also provides a practical guide for materials design in battery technology. The interplay of substrate and electrolyte interfaces emerges as a decisive factor controlling lithium metal growth, ultimately shaping the rechargeable battery landscape. By embracing this complex but rich interfacial physics, the path toward safer, more efficient, and longer-lasting lithium metal batteries appears distinctly brighter.

Subject of Research: Lithium nucleation mechanisms and interfacial control in lithium metal batteries.

Article Title: Nucleation processes at interfaces with both substrate and electrolyte control lithium growth.

Article References:
Hui, Z., Yu, S., Wang, S. et al. Nucleation processes at interfaces with both substrate and electrolyte control lithium growth. Nat. Chem. (2025). https://doi.org/10.1038/s41557-025-01911-y

Image Credits: AI Generated