压力对三元锂电池膨胀及充放电性能的影响

用三元锂电池制成的电池组必须用结构件进行封装,其封装的压力及在充放电过程中发生膨胀产生的压力都对电池性能有很大影响。通过对50 Ah软包装锂电池在恒压和恒变形两种状态进行了测试,实验结果显示:在0~5 000 N的恒压力下0.5 C充放电,单电池电压在3.0~4.2 V范围内,电池厚度最大膨胀量基本保持不变,为电池厚度的1.8%左右;电池容量随着压力的增加有所降低;在0~5 000 N压力范围内保持变形不变下进行0.5 C充放电,电池充放电过程承受的压力相对初始压力的变化量为40%左右,电池容量随初始压力增加有所降低。

Effect of pressure on charge and discharge performance and expansion of ternary lithium battery

The package made of soft package batteries must use the encapsulation structure.The encapsulation pressure and expanding pressure have great influence on batteries performance during charging and discharging.The 50 Ah ternary lithium battery of soft package was tested under constant pressure and constant deformation.The results show during charging and discharging at 0.5 C and under pressure of 0-5 000 N and 3.0-4.2 V,the maximum swell increment of the battery keeps constant for 1.8％ of the battery thickness;the battery capacity decreases as the pressure increases;on the condition of constant deformation,the maximum pressure increment is 40％,and the battery capacity decreases as the initial pressure increases.