不同充电模式对锂离子电池极化特性影响

发布时间：2018-05-01 17:33

本文选题：锂离子电池 + 电池极化　；参考：《电工技术学报》2017年12期

【摘要】：锂离子电池大电流快速充电成为近年来的发展趋势,但大电流充电很容易在电池内部引起严重极化,影响电池的性能与寿命。本文研究不同充电模式对锂离子电池极化特性的影响规律,首先,建立基于LiMn_2O_4/石墨电池的电化学-热耦合瞬态计算模型,充分考虑充电过程中电池内部的电化学过程和内热源实时变化,通过变电流充电时电池端电压变化和电解液浓度的空间分布规律,研究电池内三种极化的时变特性。然后,研究不同恒流充电倍率下电池端电压和极化电压随SOC的变化规律,提出表征电池极化程度和极化电压对电池充电过程影响的变量P_A与SOC_c,定量分析不同充电条件下极化电压对锂离子电池充电过程的影响。最后,研究Reflex快速充电条件下极化电压的变化规律,分析不同正向充电时间t_(ch)对电池极化及充电过程的影响,并给出了建议t_(ch)值。结果表明,极化电压受充电电流和SOC的直接影响,而其变化又直接影响电池端电压的变化,Reflex快充方法能有效抑制电池极化,减弱其对充电的影响。
[Abstract]:The rapid charging of large current in lithium ion batteries has become a trend of development in recent years. However, large current charging is very easy to cause serious polarization in the battery and affect the performance and life of the battery. In this paper, the influence of different charging modes on the polarization characteristics of lithium ion batteries is studied. First, the electrochemical thermal coupling based on LiMn_2O_4/ graphite battery is built. The transient calculation model takes full consideration of the electrochemical process inside the battery and the real-time change of the internal heat source in the charging process. The time variation characteristics of three kinds of polarization in the battery are studied by the change of the voltage of the battery end and the spatial distribution of the electrolyte concentration when the current is charged. Then, the battery terminal voltage and the polarization voltage of the battery are studied. With the changing law of SOC, the variable P_A and SOC_c that characterise the influence of polarization and polarization voltage on battery charging process are presented. The influence of polarization voltage on the charging process of lithium ion batteries under different charging conditions is quantitatively analyzed. Finally, the change law of polarization electrical pressure under the fast charging condition of Reflex is studied, and the different positive charging time t is analyzed. The effect of CH on the battery polarization and charging process is given and the proposed t_ (CH) value is given. The results show that the polarization voltage is directly affected by the charging current and the SOC, and the change of the voltage is directly affected by the change of the battery terminal voltage. The Reflex fast charging method can effectively suppress the battery polarization and weaken its influence on the charging.

【作者单位】：输配电装备及系统安全与新技术国家重点实验室(重庆大学);国网四川省电力公司电力科学研究院;国网重庆市电力公司电力科学研究院;
【基金】：中央高校基本科研业务费项目资助(CDJZR13150051)
【分类号】：TM912

【相似文献】