磷酸铁锂动力电池性能研究

Study on the Performance of LiFePO_4 Power Batery

采用导电性能优异的纳米碳管替代部分导电碳用以制作磷酸铁锂正极片,磷酸铁锂电池的充放电性能得到极大改善,电池内阻由未掺纳米碳管的7.5±0.5Ω降为1.7±0.3Ω,电池1 C电流下充放循环700次,容量未见衰减,维持在10 Ah。-20℃下放电容量为25℃时容量的57.35%。与1C下的放电容量相比,5 C下的放电容量未见减小。电池的优异电化学性能主要归功于整个电池电导性能的改进。

In the making process of LiFePO4 positive electrode film,part of electrical carbon was replaced by some carbon nano tubes（CNTs）,its electrochemical performance was improved greatly.The battery resistance after replaced by CNTs was decreased from 7.5±0.5 Ω to 1.7±0.3 Ω,its discharge capacity kept very well at 10 Ah after 700 charge-discharge cycles at 1C.At-20 ℃,the battery can discharge 57.35 % capacity of that at 25 ℃,and the discharge capacity at 5C is almost the same as 1C.This excellent performance can be attributed to the improvement of electrode conductive property.