Robust Temperature Estimation in All-Solid-State Batteries

This paper proposes a robust observer for temperature estimation in All-Solid-State Batteries (ASSBs) based on a coupled electrochemical-thermal model. The thermal subsystem is modeled using a quintuple-state structure that captures the temperature dynamics of five key components: the cathode, electrolyte, anode, and the surfaces near the cathode and anode. The thermal model is driven by electrochemical heat generation, which is derived from a physics-based electrochemical model, in which the cathode diffusion coefficient depends on the cathode temperature. To ensure robustness under modeling uncertainties, the observer gain is designed such that the estimation error dynamics achieve D-stability, constraining the observer poles to lie within a prescribed disk in the complex plane. For simulation purpose, a piecewise time-discretized implementation of the coupled model is adopted. Simulation results under the Urban Dynamometer Driving Schedule (UDDS) demonstrate the accuracy of the proposed temperature observer and its robustness to parameter uncertainties, demonstrating its potential for reliable thermal monitoring and enhanced safety in ASSBs.