A Practical Lithium-ion Battery Model Based on the Butler-Volmer Equation

Abstract

For Li-ion batteries based energy storage devices, the residual runtime is one of the most important indexes for the energy management and optimization in smart grid and electric vehicle applications. In this present study, the residual runtime of batteries is indicated by the residual available energy and the index of State of Energy (SOE) instead of the traditional State of Charge (SOC). To improve the accuracy of SOE estimation, a novel practical Li-ion battery model is built in this work against the dynamic load and the non-linear battery effects. To acquire advantages of both models, a Butler-Volmer equation-based electrochemical model is merged with an electrical model based on principles of electrochemistry from the discharge curve of the battery. Commercial Li-ion batteries are tested at single-cell level under dynamic loads for model validation. Simulation results verify the high precision and robustness of the proposed battery model.