Stresses in Porous Electrodes with Particle-Particle Contact and Binder Influence

Abstract

Particle fracture and particle-binder interface debonding caused by stress will induce the performance deterioration of Li-ion battery porous electrodes. Here we developed a model to systematically investigated the effect of direct particle-particle contact and the effect of binder on stress evolution. The stress in active particle with only particle contact, with only binder contact and with both contacts were numerically studied. The influence of particle size, lithium flux at the particle–binder interface, the binder elastic modulus, and binder coverage ratio on the stress development and particle-binder interface debonding were explored. The numerical study indicates that there is significant stress in the area of direct contact between particles. Moreover, the interfacial debonding decreases with the increasing of particle size and C-rate, and with the decreasing of binder elastic modulus. The optimized binder coverage ratio was obtained. This work provides guidance for optimizing battery performance by rationally designing parameters in porous electrodes.