Charging Optimization of Lithium-ion Batteries Based on Capacity Degradation Speed and Energy Loss

In order to prolong the battery life, a charging optimization in lithium-ion batteries based on capacity degradation speed and energy loss is proposed in this paper. Frist, a first-order equivalent circuit model of the battery is established and the parameters of the model under different SOC and charging rates are identified. Second, the degradation characteristics of the battery life in different SOC cycle intervals are analyzed and a capacity degradation speed model which is related to SOC and charging rate is established. Third, the energy loss is calculated based on the equivalent circuit model and the objective function that aims to reduce the capacity degradation speed and energy loss is established. Finally, the optimal current sequence is obtained by dynamic programming algorithm. Compared with the traditional charging method, the loss of the energy and capacity are reduced under the same average charging rate and the battery cycle life is effectively improved after suffering 300 cycle life verification tests.