Enhanced Performance of Li-Ion Batteries via Modified Reference Governors and Electrochemical Models

This paper examines reference governor (RG) methods for satisfying state constraints in Li-ion batteries. Mathematically, these constraints are formulated from a first principles electrochemical model. Consequently, the constraints explicitly model specific degradation mechanisms, such as lithium plating, lithium depletion, and overheating. This contrasts with the present paradigm of limiting measured voltage, current, and/or temperature. The critical challenges, however, are that: 1) the electrochemical states evolve according to a system of nonlinear partial differential equations, and 2) the states are not physically measurable. Assuming available state and parameter estimates, this paper develops RGs for electrochemical battery models. The results demonstrate how electrochemical model state information can be utilized to ensure safe operation, while simultaneously enhancing energy capacity, power, and charge speeds in Li-ion batteries.