锂离子电池健康状态估计方法

为研究动力锂离子电池的健康状态( state of health,SOH),根据SOH和荷电状态( state of charge,SOC)的定义以及电池的二阶电阻电容( resistance-capacitance,RC)等效电路模型,建立了基于恒流充电阶段电池电压曲线的SOH估计模型。通过分析电池循环寿命测试数据,利用恒流充电阶段电池电压曲线对SOH进行估计,并与试验数据进行了对比,在SOH值衰减至80%之前,SOH估计的相对误差均在±2%范围内,能较好地吻合试验结果。结果表明：所提出的估计方法具有可行性和精确性。

Methods for SOH Estimation of Li-ion Battery

To study lithium ion battery state of health ( SOH) , according to the definitions of SOH and state of charge ( SOC) and 2RC ( resistance-capacitance) battery equivalent circuit model, the SOH estimation model of the battery voltage curve based on the constant current charging stage was established. Based on the analysis of the battery cycle life test data, the SOH was estimated by the battery voltage curve of the constant current charging stage and compared to the testing data. The relative error of SOH estimation was in the range of 2% before the SOH value was reduced to 80%, which was well consistent with the experimental results. The results show that the proposed method is feasible and accurate.