Sensitivity Analysis of Electrochemical Model Parameters for Lead-acid Batteries

A high-precision electrochemical model of lead-acid batteries is the core foundation for enhancing the safety of battery management systems. However, the numerous parameters and strong coupling characteristics of the model make identification difficult. In order to explore the design basis for an efficient and accurate parameter identification framework, this paper conducted a parameter sensitivity analysis. The parameter value ranges for 23 variables were determined based on established lead-acid battery literature. The sensitivity analyses were then performed across different C-rates and depth of discharge regions, primarily evaluating parameter identifiability. Additionally, the impact of parameter uncertainty on critical model outputs, specifically electrolyte concentration and side reaction overpotential, was quantified under constant-current charging conditions. The results indicate that capacity and electrochemically relevant parameters with high sensitivity significantly influence the terminal voltage. Accordingly, this paper proposes a stepwise identification strategy and clarifies the optimal identification conditions for different parameters: capacity-related parameters are suitable for low-current conditions, while electrochemical parameters require identification under high-rate currents.