Three Dimensional Thermal-, Electrical-, and Electrochemical-Coupled Model for Cylindrical Wound Large Format Lithium-ion Batteries

A numerical model for cylindrical wound lithium-ion cells, which resolves thermal, electrical and electrochemical coupled physics, is presented in this paper. Using the Multi-Scale Multi-Domain (MSMD) model framework, the wound potential-pair continuum (WPPC) model is developed as a cell domain submodel to solve heat and electron transfer across the length scale of cell dimension. By defining the cell composite as a wound continuum, the WPPC model can evaluate layer-to-layer differences in electrical potential along current collectors, and electric current in the winding direction to investigate the effects of thermal and electrical configurations of a cell design, such as number and location of tabs, on performance and life of a cylindrical cell. In this study, 20-Ah large-format cylindrical cell simulations are conducted using the WPPC model with the number of electrical tabs as a control parameter to investigate how macroscopic design for electrical current transport affects microscopic electrochemical processes and apparent electrical and thermal output.