Electrochemical State Observer Design for Li-Ion Batteries With Heterogenous Electrode Lithiation

Real-time reconstruction of electrochemical state information is essential for high-fidelity monitoring and high-performance operation in advanced battery management systems. In this letter, a Partial Differential Equation (PDE) based observer is developed for a simplified Doyle-Fuller-Newman electrochemical model of a Li-ion battery. This observer enables the reconstruction of the internal states of the battery based on current and voltage measurements while also exploring the impact of including new sensor technologies in the battery cell. In particular, the exploitation of reference electrode and fiber-optic sensors is considered. Stability analysis of the observer components is done using Lyapunov techniques, their effectiveness in spatially tracking the electrochemical states of the original system is demonstrated through simulation results, and robustness to noise in input is analyzed.