Internal Cell Temperature Estimation Based on EIS Considering SOC and Temperature

Experiments were carried out under diverse temperatures and states of charge (SOC) to establish the relationship between SOC, temperature, and EIS impedance phase angles. A corresponding mathematical model was deduced, which further facilitates a quantitative correlation between EIS phase angles and both SOC and temperature.

This enables the accurate estimation of the internal cell temperature. The results, through analysis, exhibit high precision, rendering them appropriate for internal temperature estimation and battery safety management.