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KAIST Identifies a Route to Faster-Charging, Longer-Lasting EV Batteries
Can electric vehicles charge quickly without sacrificing battery longevity? A KAIST research team has identified a potential solution using a three-dimensional digital twin—a virtual model that recreates the internal microstructure of a real battery electrode. The team found that fast-charging performance and degradation behavior are influenced not only by the amounts of materials and pore space within the electrode, but also by how they are distributed.
KAIST (President Choongsik Bae) announced on August 24 that a research team led by Professor Kang Taek Lee from the Department of Mechanical Engineering, in collaboration with Professor EunAe Cho of the Department of Materials Science and Engineering, constructed a 3D digital twin informed by the microstructure and specifications of a commercial graphite anode. Using the model, the researchers quantitatively analyzed localized degradation mechanisms that arise during fast charging.
A lithium-ion battery anode consists of graphite, which stores lithium; a binder that holds the graphite particles together; and electrolyte-filled pore space where lithium ions travel. When a battery is charged, lithium ions move into the graphite particles in the anode where they are intercalated and stored. But if charging happens too quickly, some lithium ions cannot enter the graphite in time and instead build up as metallic lithium on the surface—a phenomenon called Li plating. It is similar to cars piling up at the entrance of a parking lot when too many arrive at once and cannot get inside fast enough. If this continues, it can degrade both battery performance and lifespan.
During charging, a thin protective film also forms on the graphite surface called the solid electrolyte interphase (SEI) layer. A properly formed SEI layer is necessary, but if it becomes too thick or uneven, it can degrade battery performance. In addition, as lithium enters the graphite particles during charging, the particles expand and push against the surrounding material, creating mechanical stress inside the electrode.
These processes occur simultaneously at the microscale, making their individual effects difficult to distinguish experimentally. Existing computational models have also relied mainly on the electrode's average properties, making it hard to capture the complex internal structure and location-dependent behavior within the electrode.
To address this, the research team built a "3D digital twin" of the battery electrode based on the structure of an actual commercial graphite anode. The team reconstructed the graphite particles, the binder that holds them together, and the electrolyte-filled pores through which lithium ions travel—all in three dimensions.
Using this virtual electrode, the researchers varied the electrode thickness, porosity, and the distribution of the binder, then simulated fast charging to analyze how lithium ions moved. They also examined where Li plating occured, how the protective film formed, and which parts of the anode experienced concentrated stress.
The results showed that even when the overall charge capacities were similar, the internal degradation behavior of the anodes could differ significantly depending on how the binder and pore space were arranged inside the electrode.
In 50-micrometer (μm) anodes, the difference in charge capacities due to binder distribution was within 4%—meaning there was little apparent difference in charging performance. Inside the electrode, however, the locations where lithium was intercalated and where performance-degrading reactions occurred differed clearly.
In particular, when the binder was concentrated near the separator, the available pore space for lithium-ion transport decreased, making it more difficult for lithium ions to move through the anode. It is much like how a narrower road causes traffic congestion. In this case, Li plating near the current collector increased by more than 10% compared to the anode with an evenly distributed binder.
Conversely, when the binder was spread relatively evenly throughout the electrode, lithium-ion transport became more uniform, and the protective film also formed more uniformly.
This difference grew larger as the electrode became thicker. In 83 μm-thick anodes, the charge capacity difference between the two binder distributions widened to about 18%. This suggests that making thicker electrodes to store more energy requires carefully designing not just how much material is used, but exactly how it is arranged inside.
The location of pore space also affected the stress the electrode experienced. Where there was enough pore space, the surrounding area could accommodate the graphite particles as they expanded during charging. Where pore space was insufficient, the graphite particles had no room to expand, concentrating stress in specific areas.
Through this study, the research team proposed a new design direction for fast-charging lithium-ion batteries: rather than simply looking at how much binder and pore space an electrode contains, researchers should also consider where and how they are distributed.
Using a 3D digital twin makes it possible to examine potential problems inside a battery in virtual space before building and testing multiple electrode designs by hand. The approach is expected to help identify optimal electrode structure, contributing to the development of batteries that can charge faster while maintaining longer service life.
"This research is significant in that it used a 3D digital twin to uncover internal battery problems that were difficult to detect from overall charging performance alone," said Professor Lee. He added that properly arranging the binder and pore space inside the electrode could help design batteries that store more energy while charge faster, and last longer.
The study, with KAIST PhD candidate Yejin Kang from the Department of Mechanical Engineering as first author, was published in the international journal InfoMat (Impact Factor 19.6) and was for the journal’s back cover on July 7.
Paper title: Digital twin quantifies spatial-heterogeneity-driven failure in fast-charging lithium-ion battery anodes,
DOI: https://doi.org/10.1002/inf2.70141
This research was supported by the Ministry of Science and ICT's Mid-Career Researcher Support Program, its Convergence Technology Development Program, and the InnoCORE Research Center.
2026.08.24 View 3546 -
Overcoming the Limits of Hydrogen Storage and Transport… KAIST Develops Next-Generation Ammonia Protonic Ceramic Fuel Cell
<(Top row, from left) Professor Kang Taek Lee, Professor Joongmyeon Bae, Dr. Tae Ho Shin, Dr. Ki-Min Roh, (Bottom row, from left) Dr. Dongyeon Kim, Researcher Dong Jae Park, Dr. Incheol Jeong>
As ammonia gains attention as a next-generation energy source capable of overcoming the limits of hydrogen storage and transport, KAIST and a joint research team have developed fuel cell technology that directly uses ammonia as fuel while achieving world-class performance and stability. This achievement is regarded as a core technology that will accelerate the commercialization of the next-generation hydrogen economy and carbon-free power generation.
KAIST (President Kwang Hyung Lee) announced on the 20th of May that Professor Kang Taek Lee and Professor Joongmyeon Bae of the Department of Mechanical Engineering, together with a joint research team including Dr. Tae Ho Shin of the Korea Institute of Ceramic Engineering and Technology (KICET, President Jong-Suk Yoon) and Dr. Ki-Min Roh of the Korea Institute of Geoscience and Mineral Resources (KIGAM, President Kwon Yi Kyun), have developed catalyst technology that dramatically improves the performance and durability of ammonia-based protonic ceramic fuel cells (PCFCs, next-generation high-efficiency fuel cells that generate electricity by transporting hydrogen ions).
<AI image: A next-generation fuel cell that generates electricity using ammonia (NH₃) as fuel>
Ammonia is attracting attention as a next-generation hydrogen carrier (Energy Carrier, a medium that stores and transports hydrogen) because it is easy to store and transport in liquid form. It is also regarded as a representative carbon-free fuel because it consists only of nitrogen (N) and hydrogen (H), producing almost no carbon dioxide (CO₂) during power generation. However, inside fuel cells, ammonia has caused problems by damaging nickel-based materials and slowing reaction rates, leading to performance degradation and shortened lifespan.
To solve this problem, the research team designed a new catalyst structure combining a “high-entropy” oxide catalyst (High-Entropy, a design method that enhances material stability and performance by mixing multiple elements) that improves structural stability by mixing multiple elements, with metal nanoparticles (Nano Particle, ultrafine metal particles on the nanometer scale) that form spontaneously on the surface during operation.
This catalyst was found not only to resist structural collapse even in an ammonia environment, but also to effectively promote the reaction that decomposes ammonia into hydrogen. Through density functional theory (DFT, Density Functional Theory, a simulation method that calculates reaction mechanisms at the atomic level) analysis, the research team identified that the high-entropy oxide structure lowers the energy barrier required for ammonia decomposition and promotes the formation of metal particles.
<AI-generated image of a high-entropy catalyst made by mixing multiple metallic elements>
In particular, the metal alloy nanoparticles that formed spontaneously on the catalyst surface showed much higher catalytic activity than single-metal catalysts. A fuel cell applying this catalyst recorded a maximum power density of 2.04 W per unit area (1 cm²) at 700°C. This means that high power can be produced from an area the size of a fingernail, representing world-class performance in the field of ammonia-based protonic ceramic fuel cells that generate electricity by transporting hydrogen ions (protons).
In addition, the cell operated stably for more than 255 hours even under harsh conditions of 600°C, significantly improving the problem of performance degradation (a phenomenon in which performance decreases over time) seen in existing catalysts.
<Schematic of an ammonia-fueled PCFC incorporating a high-entropy catalyst>
<Microstructure and elemental distribution results of the high-entropy catalyst>
Professor Kang Taek Lee stated, “Through the synergistic structure of high-entropy oxides and alloy nanoparticles, we improved both the performance and durability of ammonia fuel cells,” adding, “This study will serve as a catalyst for accelerating the commercialization of ammonia-based carbon-free power generation technology and next-generation hydrogen energy systems.”
This research, with Dr. Dongyeon Kim of the Department of Mechanical Engineering at KAIST, researcher Dong Jae Park of the Korea Institute of Ceramic Engineering and Technology, and Dr. Incheol Jeong of the Korea Institute of Geoscience and Mineral Resources as co-first authors, was published on April 17 in Nano-Micro Letters (IF: 36.3), an international journal in the fields of energy and materials.
※ Paper title: “Entropy-Modulated Oxide–Metal Catalyst Architectures for Direct Ammonia Protonic Ceramic Fuel Cells,” DOI: https://link.springer.com/article/10.1007/s40820-026-02194-9
This research was supported by the Mid-Career Researcher Program of the Ministry of Science and ICT, the Global Basic Research Laboratory Program, the InnoCORE Program of the Institutes of Science and Technology, and the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources.
2026.05.20 View 1612 -
KAIST Achieves 3-fold Increase in Hydrogen Production Using “High-Entropy” Design—More Mixing, More Strength
<(From Left) Professor Kang Taek Lee, Ph.D candidate Seeun Oh, Researcher Incheol Jeong, Dr. Dongyeon Kim, Ph.D candidate Hyeonggeun Kim>
While mixing materials typically leads to instability, there exists a phenomenon known as “high entropy,” where increasing compositional complexity can actually enhance stability. KAIST researchers leveraged this principle to enable faster proton transport and more efficient reactions within electrochemical cells, developing a technology that significantly improves hydrogen production efficiency. This breakthrough is expected to reduce hydrogen costs and accelerate the transition to clean energy.
KAIST (President Kwang Hyung Lee) announced on the 5th of April that a research team led by Professor Kang Taek Lee from the Department of Mechanical Engineering has developed a novel oxygen electrode material that dramatically improves reaction kinetics and power performance through entropy-maximized design. The oxygen electrode is a key component in electrochemical cells where oxygen evolution occurs during hydrogen production.
Green hydrogen—produced from water without carbon emissions—is considered a cornerstone of future clean energy systems. In particular, protonic ceramic electrochemical cells (PCECs), which generate hydrogen by splitting water using electrical energy while protons migrate through the cell, have attracted attention for their high efficiency. However, their performance has been limited by slow reaction kinetics at the oxygen electrode.
To address this issue, the research team adopted a high-entropy strategy, introducing multiple metal elements simultaneously to increase configurational disorder. Although mixing many elements typically destabilizes structures, under certain compositions, maximizing entropy can instead stabilize a single-phase structure.
<Structural and chemical characterization of PBSCF and PLNNCBSCF. XRD patterns of a) the synthesized PBSCF and PLNNCBSCF and b) enlarged view of the XRD patterns from 31.5 to 33.5°. c) Rietveld refinement results of the XRD profile for PLNNCBSCF, with the inset showing the idealized structure. d) HR-TEM image of PLNNCBSCF with the inset showing lattice fringes. e) Corresponding EDS mappings of the PLNNCBSCF elements. XPS of F) survey peak, G) Pr 3d, and H) O 1s spectra for PBSCF and PLNNCBSCF>
Based on this concept, the researchers designed a high-entropy double perovskite oxygen electrode by incorporating seven different metal elements (Pr, La, Na, Nd, Ca, Ba, Sr) into the A-site of the electrode structure. This material combines a perovskite crystal framework with a double perovskite structure, further enhanced by high-entropy design.
The presence of multiple mixed metal elements improves charge transport and oxygen-related reactions within the electrode, resulting in significantly faster electrochemical reactions for both electricity generation and hydrogen production.
Notably, density functional theory (DFT) calculations revealed that the energy required to form oxygen vacancies—active sites where reactions occur—was reduced by more than 60% compared to conventional materials. This indicates that reactive sites can form more easily and in greater abundance.
Additionally, time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis showed that proton transport speed increased by more than sevenfold, demonstrating that hydrogen generation processes proceed much more efficiently within the electrode.
The performance improvements were substantial. Cells incorporating the new electrode achieved a power density of 1.77 W cm⁻² at 650°C, approximately 2.6 times higher than conventional systems. Hydrogen production performance also improved by approximately threefold (4.42 A cm⁻²) under the same conditions.
Moreover, in long-term testing under steam conditions for 500 hours, performance degradation was only 0.76%, confirming excellent durability and stability over extended operation.
Professor Kang Taek Lee stated, “This study demonstrates that the thermodynamic concept of entropy can be used to control electrode reactivity,” adding, “It has the potential to significantly enhance green hydrogen production efficiency and accelerate the commercialization of the hydrogen economy.”
This study was co-led by Seeun Oh of the Department of Mechanical Engineering at KAIST and Incheol Jeong of the Korea Institute of Geoscience and Mineral Resources. The findings were published on December 16, 2025, in the international journal Advanced Energy Materials (IF: 26.0) and were selected as a front cover article, highlighting their scientific impact.
※ Paper title: “Unveiling Entropy-Driven Performance Enhancement in Double Perovskite Oxygen Electrodes for Protonic Ceramic Electrochemical Cells,” DOI: https://doi.org/10.1002/aenm.202503176※ Authors: Seeun Oh (KAIST, first author), Incheol Jeong (Korea Institute of Geoscience and Mineral Resources, first author), Dongyeon Kim (second author), Hyeonggeun Kim (second author), Kang Taek Lee (corresponding author)
This research was supported by the Mid-Career Researcher Program and the Global Basic Research Laboratory Program funded by the Ministry of Science and ICT (MSIT), Korea.
2026.04.06 View 1307 -
KAIST, Production Temperature ↓ by 500°C, Power Output ↑ 2x… Next-Generation Ceramic Electrochemical Cell Reborn
<(Top row, from left) Professor Kang Taek Lee, Ph.D candidate Yejin Kang, Dr. Dongyeon Kim, (Bottom row, from left) M.S candidate Mincheol Lee, Ph.D candidate Seeun Oh, Ph.D candidate Seungsoo Jang, Ph.D candidate Hyeonggeun Kim>
As power demand surges in the AI era, the “protonic ceramic electrochemical cell (PCEC),” which can simultaneously produce electricity and hydrogen, is gaining attention as a next-generation energy technology. However, this cell has faced the technical limitation of requiring an ultra-high production temperature of 1,500°C. A KAIST research team has succeeded in establishing a new manufacturing process that lowers this limit by more than 500°C for the first time in the world.
KAIST (President Kwang Hyung Lee) announced on the 4th of December that Professor Kang Taek Lee’s research team in the Department of Mechanical Engineering developed a new process that enables the fabrication of high-performance protonic ceramic electrochemical cells at temperatures more than 500°C lower than before, using “microwave + vapor control technology” that leverages microwave heating principles and the diffusion environment of chemical vapor generated from specific chemical components.
The electrolyte—the key material of protonic ceramic electrochemical cells—contains barium (Ba), and barium easily evaporates at temperatures above 1,500°C, which has been the main cause of performance degradation. Therefore, the ability to harden the ceramic electrolyte at a lower temperature has been the core issue that determines cell performance.
As power demand surges in the AI era, the “protonic ceramic electrochemical cell (PCEC),” which can simultaneously produce electricity and hydrogen, is gaining attention as a next-generation energy technology. However, this cell has faced the technical limitation of requiring an ultra-high production temperature of 1,500°C. A KAIST research team has succeeded in establishing a new manufacturing process that lowers this limit by more than 500°C for the first time in the world.
KAIST (President Kwang Hyung Lee) announced on the 4th of December that Professor Kang Taek Lee’s research team in the Department of Mechanical Engineering developed a new process that enables the fabrication of high-performance protonic ceramic electrochemical cells at temperatures more than 500°C lower than before, using “microwave + vapor control technology” that leverages microwave heating principles and the diffusion environment of chemical vapor generated from specific chemical components.
The electrolyte—the key material of protonic ceramic electrochemical cells—contains barium (Ba), and barium easily evaporates at temperatures above 1,500°C, which has been the main cause of performance degradation. Therefore, the ability to harden the ceramic electrolyte at a lower temperature has been the core issue that determines cell performance.
To solve this, the research team devised a new heat-treatment method called “vapor-phase diffusion.” This technique places a special auxiliary material (a vapor source) next to the cell and irradiates it with microwaves to quickly diffuse vapor. When the temperature reaches approximately 800°C, the vapor released from the auxiliary material moves toward the electrolyte and tightly bonds the ceramic particles. Thanks to this technology, a process that previously required 1,500°C can now be completed at just 980°C. In other words, a world-first ceramic electrochemical cell fabrication technology has been created that produces high-performance electricity at a “low temperature” without damaging the electrolyte.
A cell fabricated with this process produced 2 W of power stably from a 1 cm² cell (roughly the size of a fingernail) at 600°C and generated 205 mL of hydrogen per hour at 600°C (about the volume of a small paper cup, among the highest in the industry). It also maintained stability without performance degradation during 500 hours of continuous operation.
In other words, this technology reduces the production temperature (−500°C), lowers the operating temperature (600°C), doubles performance (2 W/cm²), and extends the lifespan (500-hour stability), achieving world-class performance in ceramic cell technology.
The research team also enhanced the reliability of the technology by using digital twins (virtual simulations) to analyze gas-transport phenomena occurring in the microscopic internal structure of the cell − phenomena that are difficult to observe in actual experiments.
<Figure 1. (a) Schematic of the vapor-diffusion-based process; (b) Surface microstructure of the electrolyte; (c) Internal barium composition ratio of the electrolyte according to processing conditions; (d) Comparison of power-generation performance with previous studies>
< Figure 2. (a) Three-dimensional reconstructed image of the protonic ceramic electrochemical cell fuel electrode according to processing conditions (b) Pore structure (c) Gas-transport simulation results >
Professor Kang Taek Lee emphasized, “This study is the world’s first case of using vapor to lower the heat-treatment temperature by more than 500°C while still producing a high-performance, high-stability cell.” He added, “It is expected to become a key manufacturing technology that addresses the power challenges of the AI era and accelerates the hydrogen society.”
Dongyeon Kim (KAIST PhD) and Yejin Kang (KAIST PhD candidate) participated as co–first authors. The research results were published in Advanced Materials (IF: 26.8), one of the world’s leading journals in energy and materials science, and were selected as the Inside Front Cover article on October 29.
(Paper title: “Sub-1000°C Sintering of Protonic Ceramic Electrochemical Cells via Microwave-Driven Vapor Phase Diffusion,” DOI: https://doi.org/10.1002/adma.202506905)
This research was supported by the MSIT’s Mid-career Researcher Program and the H2 Next Round Program.
2025.12.05 View 6389