TY - JOUR
T1 - A Multiphysics Aging Model for SiOx–Graphite Lithium-Ion Batteries Considering Electrochemical–Thermal–Mechanical–Gaseous Interactions
AU - Ma, Xiao Ying
AU - Li, Xue
AU - Kang, Meng Ran
AU - Shi, Jintao
AU - Fan, Xingcun
AU - Cong, Zifeng
AU - Feng, Xiaolong
AU - Jiang, Jiuchun
AU - Yang, Xiao Guang
N1 - Publisher Copyright:
© 2026 by the authors.
PY - 2026/1
Y1 - 2026/1
N2 - Silicon oxide/graphite (SiOx/Gr) anodes are promising candidates for high energy-density lithium-ion batteries. However, their complex multiphysics degradation mechanisms pose challenges for accurately interpreting and predicting capacity fade behavior. In particular, existing multiphysics models typically treat gas generation and solid electrolyte interphase (SEI) growth as independent or unidirectionally coupled processes, neglecting their bidirectional interactions. Here, we develop an electro–thermal–mechanical–gaseous coupled model to capture the dominant degradation processes in SiOx/Gr anodes, including SEI growth, gas generation, SEI formation on cracks, and particle fracture. Model validation shows that the proposed framework can accurately reproduce voltage responses under various currents and temperatures, as well as capacity fade under different thermal and mechanical conditions. Based on this validated model, a mechanistic analysis reveals two key findings: (1) Gas generation and SEI growth are bidirectionally coupled. SEI growth induces gas release, while accumulated gas in turn regulates subsequent SEI evolution by promoting SEI formation through hindered mass transfer and suppressing it through reduced active surface area. (2) Crack propagation within particles is jointly governed by the magnitude and duration of stress. High-rate discharges produce large but transient stresses that restrict crack growth, while prolonged stresses at low rates promote crack propagation and more severe structural degradation. This study provides new insights into the coupled degradation mechanisms of SiOx/Gr anodes, offering guidance for performance optimization and structural design to extend battery cycle life.
AB - Silicon oxide/graphite (SiOx/Gr) anodes are promising candidates for high energy-density lithium-ion batteries. However, their complex multiphysics degradation mechanisms pose challenges for accurately interpreting and predicting capacity fade behavior. In particular, existing multiphysics models typically treat gas generation and solid electrolyte interphase (SEI) growth as independent or unidirectionally coupled processes, neglecting their bidirectional interactions. Here, we develop an electro–thermal–mechanical–gaseous coupled model to capture the dominant degradation processes in SiOx/Gr anodes, including SEI growth, gas generation, SEI formation on cracks, and particle fracture. Model validation shows that the proposed framework can accurately reproduce voltage responses under various currents and temperatures, as well as capacity fade under different thermal and mechanical conditions. Based on this validated model, a mechanistic analysis reveals two key findings: (1) Gas generation and SEI growth are bidirectionally coupled. SEI growth induces gas release, while accumulated gas in turn regulates subsequent SEI evolution by promoting SEI formation through hindered mass transfer and suppressing it through reduced active surface area. (2) Crack propagation within particles is jointly governed by the magnitude and duration of stress. High-rate discharges produce large but transient stresses that restrict crack growth, while prolonged stresses at low rates promote crack propagation and more severe structural degradation. This study provides new insights into the coupled degradation mechanisms of SiOx/Gr anodes, offering guidance for performance optimization and structural design to extend battery cycle life.
KW - SiO/graphite anode
KW - cycling aging
KW - electrochemical–thermal–mechanical–gaseous coupled modeling
KW - lithium-ion batteries
UR - https://www.scopus.com/pages/publications/105028621075
U2 - 10.3390/batteries12010030
DO - 10.3390/batteries12010030
M3 - Article
AN - SCOPUS:105028621075
SN - 2313-0105
VL - 12
JO - Batteries
JF - Batteries
IS - 1
M1 - 30
ER -