锂离子动力电池脉冲功率特性的研究

Study on pulse power characteristics of lithium ion power battery

对自行研制的17Ah高功率型锂离子动力电池室温下的脉冲功率特性进行了研究。采用控制电流和控制功率脉冲充放电的方法研究电池在50%SOC下的脉冲充放电特性,然后以控制电流脉冲充放电模式循环,研究电池容量和功率的衰减规律。结果显示,电池在控制电流脉冲充放电模式下的功率变化范围为-500～338W,能量效率为96.2%;在控制功率脉冲充放电模式下的电流变化范围为-51.7～39.4A,容量效率为93.7%。电池以控制电流脉冲充放电模式循环1.7万次(2833h)后容量衰减了7.9%,放电功率衰减了13.1%。发现循环过程中容量和功率的衰减都呈现出先快后慢的衰减规律,功率的衰减主要发生在前1000次循环。

The charge and discharge pulse power capability of 17 Ah high power lithium ion battery for hybrid electric vehicle was studied at room temperature. Firstly, pulse power property of the battery at 50%SOC was tested under current control and power control mode, respectively; secondly, the cycle dependence of the capacity and power fade was studied under current control mode. The results show that the battery displays a power range of --500-- 338 W under current control mode, and a current range of --51.7--39.4 A under power control mode; the energy efficiency of the battery is 96.2% and the capacity efficiency is 93.7%, respectively. The battery shows a capacity fade of 7.9% and a power fade of 13.1% after 17 000 cycles （2 833 h） under current control mode. Capacity fade and power fade in the battery are fast at the beginning of cycling, but the fading rates decrease with cycle number. Most of the power fade occurs in the first 1 000 cycles.