KU Research Group Has Uncovers the Mechanism behind Room-Temperature Silicon-Based Anode Degradation
- categorization Research
- writing date 2025.10.15
- author Communication Team
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KU Research Group Has Uncovers the Mechanism behind Room-Temperature Silicon-Based Anode Degradation
△ Mechanism behind rapid capacity loss at room temperature in lithium-ion batteries using a graphite/SiO composite anode
Professor Yu Seung-ho’s research group at the Department of Chemical and Biological Engineering at KU (President Kim Dong-One), together with Professor Moon Jang-hyeok’s group from Chung-Ang University, has found the cause of the sudden performance decline that occurs in the silicon-based anodes of lithium-ion batteries when operated at room temperature.
The results of this study were published online on September 3 in Advanced Energy Materials (IF=26.0), an international journal in the field of energy materials.
*Article title : Origins of Abrupt Capacity Degradation in Lithium-Ion Batteries with Silicon-Based Anodes
*DOI: 10.1002/aenm.202502143
*URL: https://doi.org/10.1002/aenm.202502143
With the recent expansion of the electric vehicle market, demand for higher-performance lithium-ion batteries has driven research into next-generation anode materials that can replace graphite. Among them, silicon oxide (SiO) has drawn attention for its high capacity and ability to mitigate volume expansion, although it is limited due to its low stability during long-term use.
Through long-term operational experiments, the research group found that rapid charge and discharge cycles at room temperature (25 °C) resulted in a sudden capacity loss in graphite/SiO anodes. However, this problem did not occur at high temperatures (50 °C or higher) or under slow charge and discharge conditions.
The research group confirmed that the cause was diffusion-induced stress resulting from lithium concentration differences. At room temperature, lithium diffusion is slow, and thus the concentration difference between the interior of a particle and the surface is increased, resulting in cracks forming on the particle surface. These cracks promote electrolyte decomposition, creating a thick film that prevents lithium ion movement. As this process repeats, the battery performance rapidly deteriorates. Ultimately, the silicon oxide forms a thick, inactive layer called a “SiO-SEI crust,” and the efficient functioning of a battery is lost.
Furthermore, the research group demonstrated that a brief “relaxation step” between charge and discharge cycles may mitigate lithium concentration differences, thereby suppressing sudden capacity decline. This shows that diffusion-induced stress is a key cause of silicon anode performance degradation.
Professor Yu said, “The results of our study fundamentally clarify the deterioration process of silicon-based anodes, providing important clues for designing long-life, high-energy batteries. Our results will greatly contribute to the commercialization of silicon-based lithium-ion batteries in the future.”
This study was supported by the Ministry of Science and ICT, the National Research Foundation of Korea, and LG Energy Solution.
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