摘要
以Li Co O2为正极材料制备成软包电池,探究不同面密度及压实密度对其快速充电性能及循环性能的影响.采用扫描电镜(SEM)及X射线衍射(XRD)技术表征正极材料表面形貌和结构的变化.实验电池以高倍率6 C充电(1 C放电)并测试其电性能.结果表明:随着面密度增加,电池内阻明显增加,放电比容量降低且循环性能变差;面密度从150 g/m2提升到220 g/m2,电池循环1 000次后容量保持率由89.06%下降到60.45%.而随着压实密度的提高,循环性能先提升后下降,适当增大压实密度可有效地减小电池内阻并缩短Li+迁移路径,循环性能也有所提升.当压实密度为3.32 g/cm3时,电池循环500次后,容量保持率有91.50%.
The effects of cathode bulk density and compaction density on fast charge and cycle properties of the soft package battery, which was prepared by using LiCo0 2 as cathode material, were studied. The morphology and structure of the cathode materials were investigated by scanning electron microscopy （ SEM） and powder X-ray diffraction （ XRD） techniques. The prepared battery was charged at high rate 6 C （discharged at 1C） to test its electrochemical properties. With the adding cathode surface density, the discharge specific capacity and the cycle performance diminish accompanied with increasing resistance. When the bulk density is increased from 150 g/m2 to 220 g/m2, the battery capacity retention ratio falls from 89.06 % to 60.45 % after 1 000 cycles. The cycle performance of LiCo〇 2 battery increases first and then drops with the adding compaction density. Appropriate increasing of press density can effectively reduce the resistance and shorten the migration path of Li＋, which improves the battery＊s cycle performance. The capacity retention ratio for the battery charged at 6 C and discharged at 1C with compaction density of 3.32 g/ cm3 is 91.50 % after 500 cycles.
出处
《有色金属科学与工程》
CAS
2017年第3期69-73,共5页
Nonferrous Metals Science and Engineering
基金
国家自然科学基金资助项目(51372104)
江西省科技计划项目(2014BBE50019)
关键词
锂离子电池
面密度
压实密度
快速充电
高倍率
lithium ion battery
surface density
compaction density
fast charge
high rate
