Volume 52

Sensitivity analysis and evolution patterns of key electrochemical parameters to temperature and SOC for lithium-ion batteries Mengshu Tian, Jiangong Zhu , Jixiang Cai, Wentao Xu, Jie Zhang, Haifeng Dai, Xuezhe Wei

Abstract

Battery modeling is a crucial method for battery design and management, in which understanding the variations in key electrochemical parameters is essential for lithium-ion battery(LIB) modeling. To analyze the sensitivity of electrochemical parameters under different conditions, this study investigates electrochemical parameters under different temperatures and states of charge (SOC) in a NCM vs. graphite lithium-ion battery. Half cells were designed and utilized to systematically acquire electrochemical parameters for the cathode. To delineate the correlation between working conditions (temperature, and SOC) and key electrochemical parameters, the evolution patterns of the electrochemical parameter matrix under different temperatures and SOC levels are quantified experimentally. Subsequently, through battery model simulation, the impacts of parameter adjustments on the external characteristics of the battery are assessed, revealing the mapping relationships among conditions, electrochemical parameters, and external battery attributes. The results indicate a high sensitivity of the solid-phase diffusion coefficient (D_s) to temperature. Within the temperature range of 10 °C to 55 °C, these parameters generally exhibit an increasing trend with rising temperature. Furthermore, as the temperature increases, both the peak values and their corresponding SOC values show a noticeable shift. Simulation results reveal that variations in these parameters significantly impact the impedance and voltage of the battery. This investigation furnishes insights for precise modeling and simulation.

Keywords lithium-ion battery, solid-phase diffusion coefficient, sensitivity analysis, parameter evolution pattern