Quintuple Thermal Model for All-Solid-State Batteries and Temperature Estimation through a Cascaded Thermal-Electrochemical Model

This study introduces a novel quintuple thermal model for all-solid-state batteries, governed by five Ordinary Differential Equations (ODEs) representing the temperatures of the case surface near the cathode, cathode, electrolyte, anode, and the case surface near the anode. The thermal model estimates temperatures by utilizing heat generated from the battery, derived from an electrochemical model that describes the concentration of lithium-ions in the cathode and electrolyte through two Partial Differential Equations (PDEs). Model reduction, achieved via Padé approximation, transforms the PDEs into four 5th-order transfer functions. The thermal model is verified using ANSYS Transient Thermal Analysis. Optimal sensor placement was implemented with a single observable option using just one sensor. Subsequently, the Kalman filter was used to estimate the temperature.