Modeling of thermo-mechanical stresses in Li-ion battery

摘要

The aim of this paper is to evaluate the thermo-mechanical behavior of a multilayer section of a lithium-ion 18650 cell during discharge. Discharging experiments with the measurements of voltage, current output and surface temperature were conducted. The model, developed in the framework of macroscopic approach, accounts for the heat generation during the battery discharge as well as the thermal expansion of each material layer of the jelly roll and can. For sake of simplicity, the mechanical behavior is assumed linear elastic and isotropic, the layers are perfectly tied and the model does not include the lithiation expansion. However, the approach helps to point out the evolution of stresses at the interfaces of the multilayer assembly during complete discharge. It introduces the question of interface cohesion/contact ageing as cycling repeats.