基于降低极化电压磷酸铁锂电池充电方法研究

Study on Charging Method of LiFePO4 Based on Reduced Polarization Voltage

以优化锂电池充电极化电压,提高充电效率为目标,研究了电池充电极化电压与SOC的关系、停歇与极化电压降的关系、放电幅值与极化电压降的关系。研究结果表明:在充电初期与充电快完成阶段,极化电压变化极大;停歇与放电能有效地降低极化电压,停歇的时间越长,极化电压降低得越多;放电幅值越大,极化电压降越大。在此基础上,以降低极化电压作为电池充电性能的评价指标,提出了基于降低极化电压的优化充电方法,并与恒流充电方法和变电流间歇充电方法的充电性能进行了对比分析。试验结果表明,提出的方法在充电效率上高于恒流充电与变电流间歇充电2到3倍,大大缩短了充电时间,充电效率达到了95.36%。

To optimize the charging polarization voltage of lithium battery, and improve the charging efficiency, the relations between the polarization voltage and SOC, the stop voltage and the polarization voltage drop, the discharge amplitude and the polarization voltage drop are studied. The research results show that the polarization voltage changes greatly at the early stage of charging and at the completion stage of charging. Pause and discharge can effectively reduce the polarization voltage, the longer the stop, the more the polarization voltage decreases. The larger the discharge amplitude, the greater the polarization voltage drop. On the basis of this, the reduction of polarization voltage is used as an evaluation index of the battery charging performance, an optimized charging method based on the reduction of polarization voltage is proposed, and the comparison has been completed in the charging performance among the proposed method, the constant current charging method and the variable current intermittent charging method. The experimental results show that the proposed method is 2 - 3 times more efficient than constant current charging and variable current intermittent charging. The proposed method greatly reduces the charging time, the charging efficiency reaches 95.36%.