Parameter sensitivity analysis of a multi-physics coupling aging model of lithium-ion batteries

Abstract

A high-precision lithium-ion battery simulation model is the basis to ensure the reliability of battery management system (BMS), and obtaining the values of model parameters accurately and efficiently is the premise of its online application. In this work, the thermal and stress fields are coupled on the electrochemical model, and the various aging mechanisms under the influence of multi-physics coupling are considered. A multi-physics coupling aging model which can simulate the internal processes of battery is established. Based on up to 10,500 simulation cases, the sensitivities to the simulation results of terminal voltage and battery temperature of 42 model parameters are analyzed, including parameters related to multi-physics field and battery aging mechanisms. The model parameters are divided into three sensitivity levels: high, medium and low. The innovative aspects of this work include the extensive number of parameters studied, the numerous simulation cases, research objects related to multi-physics coupling and battery aging, and the concurrent parameter sensitivity analysis to both voltage and temperature simulation results. This work plays an important guiding role in the accurate and efficient identification of model parameters, and is of great significance for online application of model.