Microstructure-Dependent Macroscopic Electro-Chemo- Mechanical Behaviors of Li-Ion Battery Composite Electrodes

Abstract

The rapid development of the electric vehicle industry has created an urgent need for high-performance Li-ion batteries. Such demand not only requires the development of novel active materials but also requires optimized microstructure of composite electrodes. However, due to complicated heterogeneous electrode microstructure, there still lacks a relationship between the electrode microstructure and the macroscopic electro-chemo-mechanical performance of the battery. In this study, electrochemical and mechanical multi-scale models are developed in order to account for the influence of the heterogeneous microstructure on the macroscopic mechanical and electrochemical behavior of the battery. It is found that porosity and particle size are two important parameters to characterize the microstructure that can affect the macroscopic mechanical and electrochemical behavior. The models developed in this study can be served as designing guidelines for the optimization for the Li-ion battery composite electrodes.

Keywords

• Li-ion battery
• microstructure
• multi-scale modeling
• electro-chemo-mechanical coupling