Modelling and analysis of the volume change behaviors of Li-ion batteries with silicon-graphene composite electrodes

Silicon-carbon composite electrode is considered as one of the most promising anode materials because of its high theoretical capacity. However, the problem of huge volume change during lithiation/de-lithiation of Si-based electrodes limits its further use. In this work, we mainly simulate the radius change on the particle scale and the thickness change on the cell scale by Comsol software, and study the electrochemical behaviour and thickness evolution of the cell under different ratios of active materials, different electrode structures, and different operating conditions, and the thickness change can be converted into stress change, which provides a basis for the analysis of the stress state of the actual cell in the operating process.

June 2023