On-line optimal ion conductivity control of Li-ion battery

The battery charging control strategies with considering battery characteristics in the high power battery energy storage applications are limited, because it is difficult to obtain the overall electrochemical characteristics. However, this information is important, because they are related on life cycle, charging speed, and efficiency. In order to improve these factors, this paper proposes to control the ion conductivity, which is one of the electrochemical characteristics as an optimal charging control strategy. It results in reducing polarization impact. This control scheme needs to measure on-line battery impedance and track its saturation points. This control scheme enhanced the charging efficiency and moderate temperature rising rate. Experimental results based on a 14.6V 40Ah LiFeMgPO4 battery are used to validate and to demonstrate the performance of the proposed control scheme.