@article{Duan2026, 
author = {Xiangrui Duan and Yangtao Ou and Shuibin Tu and Wenyu Wang and Hengtao Shen and Guocheng Li and Yuanjian Li and Junjie Fu and Ruikang Feng and Renming Zhan and Yongming Sun},
title = {Understanding and regulation of stress-induced structural evolution in silicon anodes for high-energy-density batteries},
year = {2026},
journal = {Nano Research},
keywords = {high energy density, structural evolution, Si-anode pouch cells, electrochemical-mechanical behavior, operando spatial stress measurement},
url = {https://www.sciopen.com/article/10.26599/NR.2026.94908467},
doi = {10.26599/NR.2026.94908467},
abstract = {Silicon (Si)-based electrodes are widely regarded as a promising anode option for next-generation high-energy batteries. Although the substantial volume expansion during charge/discharge cycles is recognized as a primary cause of Si-based anode failure, the correlation between material volume changes, electrode-scale electrochemical-mechanical behavior, and electrochemical performance remains unclear. This poses a significant obstacle to the design of high-performance Si-based anodes. Herein, by combining operando detection of spatial stress in pouch cells (8 × 8 cm) with materials characterization, we elucidate the dependence of electrochemical performance on the inner stress-driven structural evolution of Si-based anodes, where large, uneven stress/strain dominates their mechanical degradation, compromising electrochemical reversibility. Significantly, we unveil that, beyond the basic function of Li compensation, prelithiation redirects the stress-induced structural evolution of the electrode from pore and crack formation to a void-filling-dominated process, effectively mitigating volume changes and reaction inhomogeneity. With ~25% prelithiation degree of the anode, LiCoO2||Si/C pouch cells, featuring an anode specific capacity of ~1300 mAh g-1 and areal capacity of ~2.3 mAh cm-2, deliver a remarkable reduction in anode porosity of 14.4% during the initial charge, in contrast to a 5.4% increase in the unprelithiated counterpart. Synchronously, electrode swelling diminishes from over 153% to below 18%. Harnessing this favorable electrochemical-mechanical behavior, the pouch cell delivers a 27.1% improvement in capacity retention after 200 cycles at 0.5 C, outside of a 90.4% increase in cumulative discharge capacity.}
}