Temperature response spatiotemporal correlation model of lithium-ion battery and temperature field reconstruction during charging and discharging processes

This study introduces an innovative approach aimed at estimating the temperature distribution inside a lithium-ion battery: By establishing a temperature response spatiotemporal correlation model (RSTCM) for battery, the transient temperature field inside the battery is directly reconstructed according to the surface temperature of the battery. Firstly, an external description of the temperature at the battery charging and discharging process is established. The presence of a definitive spatiotemporal correlation among the temperatures at various nodes within the battery is confirmed. Furthermore, a spatiotemporal correlation matrix for temperature responses is constructed using regularization optimization techniques. The temperature RSTCM for battery is established, which utilizes surface temperature measurement data to estimate the temperature distribution. This study utilizes discharge experiment data from lithium battery to validate the RSTCM model. Additionally, numerical simulations are conducted to analyze the impact of various factors on the reconstruction results, including the number of measurement points, charge and discharge rates, measurement errors, and model mismatches. During the charging/discharging process, the reconstructed battery temperature field exhibits an instantaneous maximum error of roughly 1.5 K. With a measurement noise standard deviation of 1.0 K, the temperature field reconstruction exhibits an instantaneous maximum error of approximately 1.3 K.