Buckling study of nanowire electrodes in a lithium-ion battery considering surface effects

Nanowire electrodes in lithium-ion batteries are susceptible to buckling during lithiation, which can cause mechanical failure and reduce battery life. This study develops an electrochemical-mechanical coupling model that incorporates surface effects and a concentration-dependent elastic modulus to investigate buckling behavior in graphite nanowire electrodes. The results show that surface tension and positive surface modulus enhance buckling resistance, whereas negative surface modulus accelerates buckling. Increasing the charging/discharging rate promotes buckling, but it has little effect on the state of charge at buckling. When surface effects are considered, elastic hardening may accelerate buckling. Particle size and slenderness ratio also significantly influence buckling behavior, and the effect of surface effects becomes more pronounced for smaller particles and larger aspect ratios. This work provides a theoretical basis for designing nanowire electrodes with improved mechanical stability.