Sensors Placement Analysis and Temperature Estimation in Lithium-Ion Batteries with a Cascaded Electrochemical-Thermal Model

This study presents a novel thermal model for cylindrical lithium-ion batteries using ten Ordinary Differential Equations (ODEs). The model covers all battery components and focuses on a simplified assembly with eight parts rolled up on a central mandrel and gaps filled with liquid electrolyte. One key input to the thermal model is the thermal power generated in the battery, calculated using a simplified electrochemical Single Particle Model (SPM) with two Partial Differential Equations (PDEs). This leads to a coupled system of 20 ODEs, where 10 ODEs represent the electrochemical model based on Pade approximation method, and 10 ODEs represent the thermal model. Temperature profiles within the battery are estimated using the Luenberger observer, with feasible sensor placement strategies discussed. Simulation results validate the model's accuracy by demonstrating temperature consistency between the thermal model and the Luenberger observer.