超低温锂离子电池性能的综合调控

Comprehensive control of ultra-low temperature Li-ion battery performance

为提高锂离子电池-40℃场景下的充放电性能,采用电导率、黏度、SEM和电化学测试等,研究电解液以及负极调控对锂离子电池低温性能的影响。当采用LiBF_(4)和VC作为添加剂的改性电解液,负极搭配硬碳材料,钴酸锂锂离子电池具备优良的超低温性能。在低温-40℃放电,容量可达常温时的94.9%。该电池具备较好的低温充电能力,在-40℃以0.2 C充电、0.5 C放电在2.5~4.2 V循环100次,容量为首次低温充电时的71.8%。

In order to improve the charge-discharge performance of Li-ion battery at-40 ℃ situation,the effects of electrolyte and anode control on low temperature performance of Li-ion battery were studied by conductivity,viscosity,SEM and electrochemical test.When the modified electrolyte which contained LiBF_(4) and VC,hard carbon anode was used,the battery had good ultra-low temperature performance.When discharged at-40 ℃ low temperature,the retention was 94.9% of that at room temperature.The battery had good low temperature charging capability.When charged at 0.2 C and discharged at 0.5 C at-40 ℃ for 100 cycles in 2.5-4.2 V,the capacity could reach 71.8% of that at the initial low temperature charging.