Lithium-ion Battery Instantaneous Available Power Prediction Using Surface Lithium Concentration of Solid Particles in a Simplified Electrochemical Model

Accurate battery power capability prediction can contribute to reliable and sufficient utilization of the battery to absorb or deliver a certain amount of power within its safe operating area. The power capability of a battery is a finite quantity that is limited by the electrochemical reaction properties occurring inside the battery. Note that the instantaneous available power of the battery is strongly related to the surface lithium concentration of solid particles in battery electrodes, but their relationship has not been explored sufficiently yet. This paper proposes a novel method for battery instantaneous available power prediction using a practical physical limit (i.e., lithium concentration limit) rather than the limits of macroscopically observed variables, such as the cell terminal voltage and current, thus providing a direct insight into electrochemical processes inside batteries. The surface lithium concentration of the solid particle is derived from a simplified battery electrochemical model, and a relationship between battery instantaneous available power and surface lithium concentration is quantified for the power capability prediction. Promising results with small forecast errors can be achieved for battery charging and discharging at different cell aging levels and ambient temperatures, which highlights the superior accuracy and robustness of the proposed method.