高电压钴酸锂/硬碳电池的化成

Formation of high voltage lithium cobaltate/hard carbon battery

以高层间距、各向异性的硬碳材料匹配高电压、高容量的钴酸锂材料,制备锂离子电池。针对硬碳材料比表面活性大、界面不稳定的问题,研究高电压钴酸锂/硬碳电池化成工艺,考察化成电流对电池首次库仑效率、dQ/dU、容量、倍率性能、贮存性能和循环性能的影响。电池以0.10 C或1.00 C充电至4.2 V循环3次进行化成后,首次库仑效率分别约为62%、69%,4.4 V下的容量分别为900 mAh、950 mAh,比能量分别为94 W·h/kg、99 W·h/kg,60.00 C放电比能量分别为81.10 W·h/kg、84.83 W·h/kg,以10.00 C充电、20.00 C放电在4.4~2.5 V循环600次,容量保持率分别为80.03%、75.47%。

Li-ion battery was prepared by matching high-voltage and high-capacity lithium cobaltate materials with hard carbon materials with high space and anisotropy.Aiming at the problems of high surface activity and unstable interface of hard carbon material,the formation process of high voltage lithium cobaltate/hard carbon battery was studied,the effects of formation current on the initial Coulombic efficiency,dQ/dU,capacity,rate capability,shelf performance and cycle performance of battery were investigated.After being formatted by charging to 4.2 V with 0.10 C or 1.00 C and cycled for 3 times,the initial Coulombic efficiency of the battery was about 62% and 69%,capacity was 900 mAh and 950 mAh at 4.4 V,specific energy was 94 W·h/kg and 99 W·h/kg,specific energy was 81.10 W·h/kg and 84.83 W·h/kg at 60.00 C discharge,the capacity retention rate was 80.03% and 75.47% after 600 cycles of charging at 10.00 C and discharging at 20.00 C in 4.4-2.5 V,respectively.