摘要
研究不同相区内的两种正极材料Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)(NCM622)和Li(Ni_(0.8)Co_(0.1)Mn_(0.1))O_(2)(NCM811)的结构变化、热稳定性及放热反应机理。两种三元正极材料在充电过程中,相变顺序为H1、M、H2和H3。当结构转变为M相时,材料在高温下开始分解释氧,当结构转变为H2相时,材料热分解临界温度降低50℃左右。所研究的两种材料中,NCM811的热稳定性较差,主要原因有两个方面:首先,NCM811转变为不稳定相的临界电压较低,M、H2相变的临界电压分别为3.60V、4.00V,低于NCM622(分别为3.67V和4.64V);其次,同处于M相时,NCM811的释氧分解温度为300℃,低于NCM622的500℃。
The structure change,thermal stability and exothermic reaction mechanism of cathode material Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)(NCM622)and Li(Ni_(0.8)Co_(0.1)Mn_(0.1))O_(2)(NCM811)under different phases were studied.The investigated two ternary cathode materials underwent phase transformations in the sequence of H1,M,H2 and H3 in charging.Under M phase,cathode material began to decompose and release oxygen;when transformed to H2 phase,the critical thermal decomposition peak of cathode material decreased about 50℃.Among the two cathode materials,NCM811 exhibited lower thermal stability which was resulted from two main reasons.Firstly,the critical voltage of NCM811 to unstable phase was lower,the critical voltage of M phase and H2 phase transition was 3.60V and 4.00V,respectively,which was lower than NCM622(3.67V and 4.64V respectively);secondly,in M phase,the decomposition temperature of NCM811 was 300℃,which was lower than 500℃of NCM622.
作者
朱振东
代娟
彭文
吴欢欢
ZHU Zhen-dong;DAI Juan;PENG Wen;WU Huan-huan(Hefei Gotion High-Tech Power Energy Co.,Ltd.,Hefei,Anhui 230012,China)
出处
《电池》
CAS
北大核心
2021年第1期54-58,共5页
Battery Bimonthly
基金
国家重点研发计划项目(2016YFB0100304)。
关键词
锂离子电池
正极材料
结构转变
热稳定性
Li-ion battery
cathode material
structural transformation
thermal stability
作者简介
朱振东(1984-),男,安徽人,合肥国轩高科动力能源有限公司工程师,博士,研究方向:锂离子电池机理及分析;通信作者:代娟(1990-),女,安徽人,合肥国轩高科动力能源有限公司工程师,硕士,研究方向:锂离子电池安全;彭文(1985-),女,安徽人,合肥国轩高科动力能源有限公司工程师,博士,研究方向:锂离子电池的开发与安全机理;吴欢欢(1989-),女,安徽人,合肥国轩高科动力能源有限公司工程师,硕士,研究方向:锂离子电池安全机理。
