An optimal charging strategy of lithium-ion batteries based on polarization and temperature rise

Abstract

The temperature rise characteristics of the Li-ion battery at different charging rate are investigated. Except the electrode tabs, the temperature rise of different positions at the battery surface is consistent, thus we can establish a battery particle thermal model to simulate the battery temperature variation at different charging rate. The temperature rise of simulation is compared with the temperature rise of experiment to verify the battery particle thermal model. Based on the battery thermal model, taking temperature rise as constraint, a boundary charging current curve is developed. Combined with the boundary charging current curve taking polarization voltage as constraint, a boundary charging current curve taking polarization voltage and temperature rise as constraint is developed. Based on the current curve, an optimal charging strategy is proposed. The experimental results demonstrate that the proposed charging strategy can not only shorten the charging time, but also enlarge the charging capacity.