无机材料学报2025，Vol.40Issue(7)：772-780,中插11-中插14,13.DOI:10.15541/jim20240472
硅电极组分梯度设计抑制力-化学耦合劣化
Composition-gradient Design of Silicon Electrodes to Mitigate Mechanochemical Coupling Degradation
摘要
Abstract
As an anode for lithium-ion batteries,silicon material has the advantage of high energy density.However,the volume effect during charge-discharge cycles causes instability in the active coating's surfaces and diffusion stress induced by internal polarization,leading to inevitable structural degradation and capacity fading.Inspired by functionally gradient materials,this study proposed a five-layer composite gradient silicon electrode.Experiments and multi-scale electro-chemo-mechanical coupled model demonstrate that the designed symmetric and linear gradient silicon electrodes effectively mitigate mechanochemical coupled degradation,showing superior cycling and rate performance compared to traditional uniform electrode.Specifically,the symmetric gradient electrode retains a specific capacity of 2065 mAh·g-1 after 100 cycles at 0.2C(1C=2.65 mA·cm-2)rate,with a capacity retention rate of 81%,while that of uniform electrode is 51%.The linear gradient electrode exhibits an average discharge capacity 1.5 times that of the uniform electrode at 1C rate.Moreover,both types of gradient electrodes demonstrate smaller impedance variations before and after cycling compared to the uniform electrode.These composite gradient electrodes are implemented through an innovative multi-layer coating process,and improved structural stability and electrochemical performance without material modifications,providing a reference for designing and fabricating high-performance silicon electrodes.关键词
锂离子电池/硅电极/功能梯度材料/多物理场耦合Key words
lithium-ion battery/silicon electrode/functionally gradient material/multi-physics field coupling分类
信息技术与安全科学引用本文复制引用
谭博文,耿双龙,张锴,郑百林..硅电极组分梯度设计抑制力-化学耦合劣化[J].无机材料学报,2025,40(7):772-780,中插11-中插14,13.基金项目
国家自然科学基金(12372173) （12372173）
上海市自然科学基金(23ZR1468600)National Natural Science Foundation of China(12372173) （23ZR1468600）
Natural Science Foundation of Shanghai(23ZR1468600) （23ZR1468600）
