溶剂PC含量对锂离子电池物化性能的影响

Effect of Solvent PC Content on Physical and Chemical Properties of Li-ion Batteries

以20100140型方形锂离子电池为样本,进行充放电和45℃条件存储时的容量损失测试实验,研究电解液中碳酸丙烯酯(PC)溶剂含量对锂离子电池物化性能的影响。结果表明:当PC质量分数为4%时,锂离子电池表现出最佳性能,压降较小,电池界面较好,容量可达32.813 Ah,在45℃高温存储6 d后放电效率可达100.28%;当PC质量分数增加到7%时仍未发生与Li+共嵌入负极石墨的现象,但随着PC含量的增加,电池电压降增大、厚度增加、电化学性能降低、石墨发生剥离;当PC质量分数为12%时,放电容量为31.503 Ah,存储后只有93.84%的放电效率,电池臌胀。

Taking 20100140 square lithium-ion battery as the sample,the charge-discharge test and capacity loss test during storage at 45℃were carried out.The effect of solvent content of propylene carbonate(PC)in electrolyte on the physicochemical properties of Li-ion battery was studied.The results show that when the mass fraction of PC is 4%,the Li-ion battery has the best performance,the voltage drop is small,the battery interface is good,the capacity can reach 32.813 Ah,and the discharge efficiency can reach 100.28%after 6 days of high temperature storage at 45℃.The phenomenon co-embedding with Li+did not occur when the mass fraction of PC increase to 7%,but with the increasing of PC content,the voltage drop and thickness of the battery increase,electrochemical properties decrease,and graphite peels off.When the mass fraction of PC is 12%,the discharge capacity is only 31.503 Ah,the discharge efficiency is only 93.84%after storage,and the battery inflates.