Lithium-ion battery impedance as a battery temperature indicator

In this study, we propose and evaluate the performance of an impedance-based model for battery temperature estimation. We used four different datasets including Electrochemical Impedance Spectroscopy (EIS) experiments measured at different conditions, including variations in technology, temperatures, State-of-Charge (SoC) and State-of-Health (SoH). One of the datasets collects new EIS data coming from new experimental tests. By means of a correlation analysis, we select the reactance of the impedance in the frequency range from 100 to 1000 Hz as the most suitable temperature indicator. Then, we evaluate the temperature estimation performance of some linear and exponential models with a cross-validation approach, using the reactance measured at a single frequency point considering also the effects of SoC and SoH. A further contribution of this manuscript is the presentation of a dataset including EIS experiments under multiple temperature and SoC conditions, that was acquired in our laboratories and published online for the scientific community. In this paper, we provide an accurate description of the tests performed.