The study, led by Professor Kang Taek Lee of the Department of Mechanical Engineering at the Korea Advanced Institute of Science and Technology, or KAIST, was conducted with Professor EunAe Cho of the Department of Materials Science and Engineering. Instead of treating a battery electrode as a uniform block with average properties, the researchers recreated its internal architecture in three dimensions, including graphite particles, binder material, and electrolyte-filled pores. The resulting model was designed to behave like a virtual counterpart of a commercial graphite anode.

That internal structure matters because a lithium-ion battery is not simply a container in which ions move smoothly from one side to another. During charging, lithium ions travel through the electrolyte-filled pores of the anode and enter graphite particles, where they are stored between layers of carbon atoms. When charging is too rapid, however, the ions may reach the graphite surface faster than they can be absorbed. Instead of intercalating into the graphite, they can accumulate as metallic lithium on the surface, a damaging process known as lithium plating.

Lithium plating is one of the most important obstacles to extreme fast charging. It can consume active lithium, reduce the battery’s usable capacity, and in some cases create structures that increase the risk of internal short circuits. At the same time, a thin protective layer called the solid electrolyte interphase, or SEI, forms on the graphite surface. The SEI is essential because it helps stabilize the electrode, but excessive or uneven growth consumes electrolyte and lithium, raises resistance, and can prevent ions from reaching the graphite efficiently.

The anode also undergoes mechanical changes during charging. As lithium enters graphite, the particles expand and push against neighboring particles, binder regions, and pore walls. If the surrounding structure has sufficient empty space, that expansion can be accommodated with less damage. If the local pore volume is too limited, mechanical stress becomes concentrated in particular regions. Because lithium transport, SEI growth, lithium plating, and mechanical deformation occur simultaneously at microscopic scales, experiments that measure only total capacity can miss the earliest signs of failure.

To expose these hidden processes, the KAIST team reconstructed the three-dimensional arrangement of the graphite particles, polymer binder, and pores in a commercial anode. The researchers then altered key structural parameters in the virtual electrode, including its thickness, porosity, and the spatial distribution of the binder. They simulated fast-charging conditions and tracked where lithium ions moved, where lithium plating occurred, how the SEI developed, and which areas experienced the greatest mechanical stress.

The simulations revealed that two electrodes with nearly identical overall compositions and apparent charging capabilities can behave very differently internally. In 50-micrometer-thick anodes, changing the binder distribution produced a capacity difference of less than 4 percent, a variation that might appear relatively minor in conventional battery testing. Yet the simulations showed clear differences in the locations where lithium was inserted into graphite and where degradation reactions were concentrated.

One particularly important result emerged when binder was concentrated near the separator, the membrane that separates the anode from the cathode while allowing lithium ions to pass. The binder occupied space that could otherwise support ion transport, effectively narrowing the pathways through which ions moved into the electrode. This created a microscopic bottleneck similar to traffic congestion on a narrowed road. Under those conditions, lithium plating near the current collector increased by more than 10 percent compared with an anode in which the binder was distributed more evenly.

A more uniform binder arrangement produced more consistent ion transport and helped the SEI form more evenly across the electrode. The contrast became substantially stronger as the anode grew thicker. In an 83-micrometer electrode, the difference in charge capacity between the two binder distributions reached approximately 18 percent. The finding highlights a growing challenge in battery engineering: thicker electrodes can store more energy per unit of area, but their greater transport distance makes them more sensitive to local variations in pores, binder, and particle arrangement.

The researchers also found that pore-space distribution influenced mechanical damage. Regions with adequate pore volume could absorb some of the expansion of graphite particles during charging, while densely packed areas forced particles against one another and developed concentrated stress. These localized effects may not immediately appear in a battery’s total voltage or capacity, but they can gradually accelerate structural damage and amplify other degradation mechanisms. The study therefore suggests that electrode design must consider not only how much graphite, binder, and pore space are present, but also their precise locations.

The digital-twin strategy could allow battery developers to test virtual electrode designs before producing and cycling large numbers of physical prototypes. By revealing where transport bottlenecks, lithium plating, uneven SEI growth, and mechanical stress are likely to occur, the model may help engineers optimize electrodes for fast charging while preserving energy density and service life. Professor Lee said the work demonstrates how three-dimensional modeling can uncover internal battery problems that remain invisible when researchers rely only on overall charging performance. The study, led by KAIST PhD candidate Yejin Kang as first author, was published in InfoMat and featured on the journal’s back cover. Its results point toward a future in which the microscopic architecture of an electrode is designed as carefully as its chemical ingredients.

Subject of Research: Three-dimensional digital-twin modeling of graphite lithium-ion battery anodes, fast-charging degradation, lithium plating, SEI formation, ion transport, binder distribution, pore structure, and mechanical stress.

Article Title: Digital twin quantifies spatial-heterogeneity-driven failure in fast-charging lithium-ion battery anodes

News Publication Date: August 24, 2026

Web References: https://doi.org/10.1002/inf2.70141

References: Kang, Y. et al., “Digital twin quantifies spatial-heterogeneity-driven failure in fast-charging lithium-ion battery anodes,” InfoMat, DOI: 10.1002/inf2.70141. Article publication date: July 7, 2026.

Image Credits: KAIST

Keywords

Lithium-ion batteries, electric vehicles, fast charging, battery degradation, lithium plating, graphite anodes, digital twins, solid electrolyte interphase, electrode microstructure, binder distribution, pore structure, battery materials, energy storage, KAIST.

The integration of a graphene oxide membrane is a masterstroke in this technology, enabling the selective permeation of gaseous species while effectively blocking organic solvent molecules. This selective barrier dramatically mitigates the loss of electrolytes and contamination in measurement, which are the primary causes of poor longevity and reliability in conventional DEMS analysis. As a result, the MDEMS system can sustain long-term gas evolution monitoring, even under conditions that mimic the practical operation of batteries, including elevated temperatures.

Electrochemical mass spectrometry (DEMS) has been an essential tool in studying battery chemistry for years, primarily by detecting gases evolved during charge and discharge cycles. However, volatile organic electrolytes housed within typical lithium-ion batteries evaporate quickly during testing, disrupting the delicate mass spectrometry balance and resulting in compromised data quality. With the MDEMS approach, the innovative membrane ensures a constant internal environment, allowing extended studies that can be conducted over weeks instead of mere days, opening unprecedented insights into battery aging and failure mechanisms.

This new analytical capability allowed researchers to explore the intricate interplay between electrolyte additives and cathode surface coatings in suppressing the deleterious side reactions that cause gas formation. Such side reactions are crucial contributors to capacity fade, increased internal resistance, and safety hazards in lithium-ion batteries. By analyzing these interactions under realistic operational conditions, the scientific team elucidated how specific additive compounds, in conjunction with specially engineered cathode layers, inhibit the gas-evolving processes that previously went uncharacterized under long-term conditions.

One of the most pressing challenges in lithium-ion battery technology has been ensuring stability at elevated temperatures while maintaining performance and safety. High temperatures accelerate the decomposition of electrolytes and promote gas evolution, which can lead to rapid battery deterioration and safety incidents such as thermal runaway. With the MDEMS platform, the researchers conducted long-term measurements at elevated temperatures, thereby mimicking real-life scenarios in electric vehicles and energy storage systems, concluding that targeted combinations of additives and coatings could dramatically mitigate gas generation and extend battery life under thermal stress.

The practical implications of this discovery are vast, potentially transforming how battery manufacturers approach electrolyte formulation and electrode surface engineering. By deploying the MDEMS technique during the development phase, quality control, and post-mortem analysis, manufacturers could optimize batteries for enhanced longevity and safer operation over diverse environmental conditions. This not only promises economic benefits by reducing battery replacements but also aligns with global sustainability goals by minimizing battery waste.

The underlying scientific achievement, of course, centers on the versatile properties of graphene oxide membranes. Graphene oxide’s unique structure allows it to selectively filter molecules by size and chemical affinity, which in this case translates into allowing small gas molecules—such as oxygen, carbon dioxide, and hydrogen—to pass while excluding larger organic solvent molecules. This selective permeability is the cornerstone of the MDEMS’s ability to maintain the electrolyte’s integrity within the measurement chamber, marking a significant materials science breakthrough in battery diagnostics.

Further, the precise detection of the types and rates of gas evolved during electrochemical cycling provides vital mechanistic insights into electrolyte decomposition and electrode interface stability. For instance, the presence of oxygen evolution might indicate cathode lattice oxygen release, while hydrogen evolution can signal electrolyte reduction at the anode. Tracking these gaseous byproducts over extended cycling enables researchers to pinpoint degradation pathways with unprecedented temporal resolution, yielding actionable data for battery improvement strategies.

This innovative use of MDEMS also holds promise for accelerating the introduction of next-generation battery systems beyond lithium-ion, including solid-state and lithium-metal technologies. These emerging chemistries often involve complex interfacial phenomena and volatile reaction products, for which reliable long-term gas analysis has been a missing piece of the puzzle. By adapting the MDEMS platform to these novel chemistries, researchers anticipate unraveling their failure modes and optimizing their component interactions before wide-scale commercialization.

The success of this technology also opens new avenues for real-time, in situ diagnostic monitoring of batteries during operation. Traditional approaches typically require disassembly or destructive testing, hindering continuous observation of dynamic processes. MDEMS, with its stability and selective permeation membrane, could be adapted into portable or integrated sensors that provide continuous feedback on battery health and performance, driving smarter battery management systems that preempt failure and extend operational lifecycle.

Importantly, the research underpinning the MDEMS system underscores the increasingly interdisciplinary nature of modern battery science, combining advanced materials engineering, electrochemistry, and analytical instrumentation. The collaboration across these fields was essential to design, fabricate, and validate a membrane that not only withstands battery conditions but also enhances the resolution and longevity of gas analysis, providing a template for future breakthroughs at the interface of material science and energy technology.

Taken together, the development and deployment of the membrane-separated DEMS system represent a landmark achievement in battery diagnostics. It promises to propel the field forward by enabling continuous, reliable, and precise monitoring of gas evolution—something that was notoriously difficult with previous methodologies. Such capability holds the promise of safer, longer-lasting batteries and accelerates the global transition to cleaner energy technologies powered by advanced electrochemical storage.

Subject of Research: Development of a membrane-separated differential electrochemical mass spectrometry system for long-term gas evolution analysis in lithium-ion batteries.

Article Title: Long-Term Gas Evolution Analysis in Lithium-Ion Batteries Enabled by Graphene Oxide Membrane-Separated DEMS.

News Publication Date: Not provided.

Web References: Not provided.

References: Not provided.

Image Credits: EurekAlert

Fast charging, while highly desirable for consumer convenience, introduces a complex electrochemical dynamic within lithium-ion cells. During rapid charge cycles, lithium ions are meant to migrate smoothly from the cathode, passing through the electrolyte, and intercalate into the graphite layers of the anode. However, under certain conditions, notably low temperatures or excessive current density, these ions instead deposit as metallic lithium on the anode surface rather than integrating into its structure. This surface deposition, termed lithium plating, detracts from the cell’s effective lithium inventory, diminishes capacity, and can provoke hazardous outcomes such as internal short circuits or thermal runaway. Despite its importance, directly observing this process as it unfolds has been notoriously difficult due to the opaque and miniature nature of battery components.

To surmount these challenges, the research team devised an operando microscopy technique that recreates realistic battery environments within transparent glass tubes. By mimicking the electrochemical and thermal conditions of conventional lithium-ion cells, this platform enables live monitoring of lithium-ion behavior down to the nanoscale. The breakthrough allows researchers to capture the initial emergence and evolution of lithium plating, providing vital quantitative data on its onset voltage and progression kinetics. This capability represents a paradigm shift, moving from indirect inference based on post-mortem analysis toward direct, dynamic observation of battery chemistry in situ.

From the detailed recordings obtained, the study identifies critical voltage thresholds that signify the transition point where benign lithium intercalation gives way to harmful plating. This newfound knowledge allows the formulation of precise charging “cut-off” parameters tailored to specific operating conditions. By discontinuing charging once this threshold is approached, operators can mitigate the risk of plating, thereby enhancing battery cycle life and operational safety. Such protocols could be integrated into battery management systems, enabling adaptive, real-time optimization that balances charge speed against long-term durability.

Beyond identifying safe charging limits, the operando microscopy approach facilitates rigorous testing and comparison of different electrolyte formulations under realistic usage scenarios. The researchers highlighted the superiority of ether-based electrolytes in suppressing plating phenomena. These electrolytes, characterized by favorable ion transport properties and stability under fast charging, demonstrate promise in advancing battery chemistries toward higher performance envelopes. Identifying electrolyte compositions that complement fast charging regimes without incurring plating damage is paramount for next-generation battery development.

A consequential outcome of this study is the generation of a comprehensive “performance map” delineating the interplay between voltage, temperature, charging rate, and plating onset. This map serves as a quantitative guidebook for battery designers and manufacturers, enabling the optimization of cell architectures and charging protocols. It encapsulates the complex electrochemical landscape in a usable format that can inform engineering decisions and software algorithms alike. The existence of such a tool is invaluable for accelerating the commercialization of safer, faster-charging batteries.

It is noteworthy that despite the considerable excitement around achieving ultra-fast charging capabilities, there is a nuanced tradeoff. Accelerated charging inherently raises the risk of lithium plating, particularly in cold ambient conditions or at high charge states near full capacity. The research underscores the practical advice that users might consider terminating charging sessions at approximately 80% state-of-charge to preserve battery health. This operational insight, underpinned by detailed mechanistic understanding, bridges the gap between laboratory discovery and everyday application.

The implications of this work extend well beyond consumer electronics into the realm of electric vehicles, where battery reliability and rapid rechargeability are critical for widespread adoption. Automatically integrated charging cut-offs based on operational feedback could prevent premature battery degradation and potential fire hazards in EV batteries. Thus, this research not only enhances scientific knowledge but also charts a pathway for safer, more durable battery deployment in large-scale mobility solutions.

Underpinning this groundbreaking work is a multidisciplinary collaboration blending materials science, chemical engineering, and computational analytics. Lead investigator Peng Bai and his doctoral students Rajeev Gopal and Bingyuan Ma exemplify the fusion of innovative experimentation with theoretical rigor. Their publication in the esteemed journal Small signals the high-impact nature of their contribution to the field. The project enjoys support from the National Science Foundation and industry partnerships such as the Toyota Research Institute, reflecting the strategic importance and broad relevance of advanced battery research.

Looking ahead, the operando microscopy platform promises to be a versatile tool for continuous refinement of lithium-ion battery technology. As researchers apply this method across diverse chemistries and configurations, iterative improvements in electrolyte formulas, electrode materials, and charging algorithms are anticipated. Such advances will be crucial in pushing the boundaries of charge speed and battery safety, ultimately catalyzing the transition to a more electrified, sustainable future.

In conclusion, this research constitutes a pioneering step toward demystifying and controlling lithium plating phenomena during fast charging. By providing direct visualization and quantitative mapping of plating onset, it empowers the design of smarter, safer battery systems capable of balancing the demand for rapid recharge with the imperative of longevity and fire safety. As lithium-ion batteries continue to permeate every facet of modern technology, innovations like these will be instrumental in shaping the next generation of energy storage solutions.

Subject of Research: Lithium plating in lithium-ion batteries during fast charging and its mitigation via operando microscopy.

Article Title: Mapping Out Fast Charging Safe Limits for High-Loading Lithium-Ion Cells by High-Fidelity Operando Microscopy.

News Publication Date: Not specified in the article (expected 2026 Jan 23 as per journal).

Web References:
https://onlinelibrary.wiley.com/doi/10.1002/smll.202514619

References:
Gopal RK, Ma B, Bai P. Mapping Out Fast Charging Safe Limits for High-Loading Lithium-Ion Cells by High-Fidelity Operando Microscopy. Small. 2026 Jan 23:e14619. DOI: 10.1002/smll.202514619.

Keywords:
Lithium-ion batteries, lithium plating, fast charging, battery safety, operando microscopy, electrolyte optimization, ether-based electrolytes, battery degradation, battery management systems, electric vehicle batteries, electrochemistry, battery performance mapping.

What stands out in this study is the multi-faceted approach that the researchers adopted for health assessment. Traditional methods often rely on direct measurements, which can fail to capture the nuances of battery dynamics and therefore lead to oversimplified interpretations of battery health. The researchers have bridged this gap by utilizing an array of indirect features that provide critical data points while monitoring battery performance. These indirect features cover a spectrum of operational parameters and physical characteristics, such as temperature variations, charge-discharge cycles, and internal resistance. By examining these data points, the researchers have created a more nuanced understanding of how various factors contribute to overall battery health and longevity.

The incorporation of indirect feature extraction has been a game changer in battery diagnostics. Through this method, the researchers were able to derive insightful correlations that highlight how specific operational conditions affect battery life. For instance, understanding how temperature fluctuations impact battery efficiency allows for more fine-tuned operational strategies that can enhance lifespan. Furthermore, this technique also enables predictive modeling that anticipates potential failures, allowing for preemptive maintenance instead of reactive measures. The study showcases how these innovative techniques can not only aid in extending battery life but also improve user safety by reducing the risk of failures.

Enhancing the decision tree with the Watermelon Particle Algorithm is another innovative aspect of this research. The WPA is a novel optimization technique that mimics the foraging behavior of watermelons, allowing for the identification of the most relevant features within the vast dataset. This optimization facilitates the creation of a robust decision-making framework that systematically classifies battery health based on the extracted indirect features. By merging these advanced computational techniques, the researchers have established a highly efficient model capable of addressing the inherent complexities of battery performance evaluations.

Moreover, the utilization of a WPA-optimized decision tree marks a significant leap in how we can interpret battery health data. Unlike conventional algorithms that may struggle with large datasets or exhibit biases, this approach offers remarkable accuracy in classification. Such precision is vital for real-time monitoring applications, where the decision-making process can impact the operational viability of electric vehicles and other battery-operated devices. Embracing this technology could lead to smarter battery management systems that are not only efficient but also enhance overall device safety.

Another compelling aspect of this study is its implications for the broader field of energy storage technologies. As lithium-ion batteries continue to dominate the market, the need for reliable assessment methods becomes increasingly critical to maximize their potential. A better understanding of battery health facilitates the development of improved charging protocols, energy management strategies, and recycling methods—contributing to a more sustainable future. By effectively integrating real-time data analytics with artificial intelligence, researchers are paving the way toward energy systems that are both efficient and environmentally friendly.

In the context of large-scale energy policies, the findings from this study also have significant ramifications. Governments and corporations alike are investing heavily in battery technology to support transitions toward renewable energy sources. Fine-tuning diagnostic tools like those developed by Si, Pan, and Liu can help evaluate the lifecycle of battery assets, ensuring that investments yield returns not just in financial terms, but also in sustainability metrics. Establishing a standard for health assessment could also promote interoperability among different battery technologies, enabling seamless transitions and integrations within energy grids.

Furthermore, as battery technology continues to evolve, ensuring compatibility between old and new battery systems becomes a challenge. This study takes a proactive step toward addressing these compatibility issues through a standardized approach to health assessment. By establishing metrics that can uniformly apply across various battery types, researchers can help facilitate collaboration among manufacturers, developers, and policymakers in creating a regulatory framework that supports innovation without compromising safety.

In conclusion, the work by Si, Pan, and Liu signifies a pivotal advancement in our understanding and management of lithium-ion batteries. This study exemplifies the intersection between technology and sustainability, where enhanced battery health assessment not only minimizes the risk of failures but also supports broader energy objectives. As this research gains traction within the scientific community, it is poised to inspire further innovations in battery technology, making it an essential addition to the ongoing conversation about energy efficiency and sustainability. As we move forward into a future increasingly reliant on batteries, embracing such sophisticated methodologies will be instrumental in unlocking the full potential of energy storage systems.

The landscape of battery technologies is changing rapidly, and continual assessment of performance metrics is critical. This study not only fills an important gap in current diagnostic practices but also sets the stage for a future where batteries are seen less as disposable commodities and more as long-term investments in sustainable energy solutions. The global tide is shifting towards more intelligent, data-driven approaches to energy management, and the methodologies developed in this research could well be the cornerstone for emerging strategies and technologies.

Ultimately, the journey of lithium-ion batteries is far from over, and with continued research and innovation, a future laden with robust, efficient, and safe energy solutions is within reach. The main takeaway from this significant study is that the health assessment of lithium-ion batteries is not merely about prolonging the life of a technology; it is about fostering a more sustainable relationship with energy consumption as a whole.

Subject of Research: Health assessment of lithium-ion batteries using multiple indirect feature extraction and WPA-optimized decision tree

Article Title: Health assessment of lithium-ion batteries using multiple indirect feature extraction and WPA-optimized decision tree

Article References:

Si, R., Pan, R., Liu, Q. et al. Health assessment of lithium-ion batteries using multiple indirect feature extraction and WPA-optimized decision tree.
Ionics (2025). https://doi.org/10.1007/s11581-025-06661-y

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s11581-025-06661-y

Keywords: Lithium-ion battery, health assessment, indirect feature extraction, Watermelon Particle Algorithm, decision tree optimization.