富锂锰基锂正极材料和动力电池的性能研究

The research about performance of li-rich manganese based li-ion material and power battery

以全浓度梯度核壳(Full Concentration Gradient Core-Shell,简称FCGC-S)富锂锰基材料为正极材料,以中间相碳微球为负极材料,采用叠片工艺制备了高电压17Ah的富锂锰基锂离子电池。从材料合成工艺、性能优化和电池设计及集成关键技术几方面,评价电池的充放电倍率性能、高低温性能、循环寿命性能等。通过优异的全浓度梯度核壳富锂锰基材料正极材料、容量匹配和负极匹配技术、电解液和添加剂的兼容性优化等集成,制作了高电压富锂锰锂离子电池。实验结果表明,电池样品的能量密度处于220Wh/kg;室温1C倍率放电容量为额定容量的97.90%,10s放电的比功率为240W/kg;低温(-20℃)1C放电容量为额定容量的90.09%;高温(55℃)1C放电容量为额定容量的93%;在室温下储存28天,荷电保持能力为97.12%,恢复容量为额定容量的97.79%;在高温(55℃)下储存7天,然后在室温下以1C电流放电荷电容量为额定容量的95.53%,恢复容量为额定容量的95.72%;标准寿命循环500次时放电容量为额定容量的95.09%。安全性能测试符合GB/T 31485-2015标准要求。

Lithium-rich manganese-based material with FCGC-S structure as cathode material,Mesophase carbon microspheres as anode material,A 17 Ah high-Voltage lithium-ion battery was fabricated by lamination process.Through material synthesis process,performance optimization,battery integration design,etc key technologies,the battery charge-discharge rate,high and low temperature performance,cycle life performance,etc.were evaluated.The test results showed that the energy density of the battery is about 220 Wh/kg,the 1 Cdischarge capacity at room temperature is 97.90%of the nominal capacity.The 10 sspecific power of discharge is 240 W/kg.The 1 C discharge capacity at low temperature(-20 C)and at high temperature(55 C)are 90.09%and93%of the nominal capacity respectively.After Stored for 28 days at room temperature,the charge retention is 97.12%of nominal capacity and capacity recovery is about 97.79%of nominal capacity.After 500 standard life cycles,the discharge capacity is 95.09%of the nominal capacity.The safety performance test meets GB/T 31485-2015 standard requirements.