在分层中调节热稳定性 (NixMnyCoz)
Jiaxin Zheng1, Tongchao Liu1, Zongxiang Hu1
1School of Advanced Materials, Peking University, Shenzhen Graduate School , Shenzhen 518055, People's Republic of China.
Journal of the American Chemical Society
|September 20, 2016
概括
在电动汽车电池中,优化,,氧化物 (NMC) 材料的热稳定性是关键. 这项研究揭示了氧气
科学领域:
- 材料科学
- 电化学
- 计算化学
背景情况:
- 多层氧化 (NMC) 材料对于电动汽车的可充电离子电池 (LIB) 是至关重要的.
- 优化NMC阴极的热稳定性对于提高电池安全性和性能至关重要.
研究的目的:
- 阐明NMC材料的热稳定性机制.
- 通过了解氧气在局部协调结构单元 (LCSU) 中的作用,建立调节热稳定性的模型.
主要方法:
- 使用初始计算与实验验证.
- 分析氧的局部协调结构单元 (LCSU),特别是TM ((Ni,Mn,Co) 3-O-Li3-x),以了解氧结合和稳定性.
主要成果:
- 热稳定性受到LCSU中最不稳定的氧原子的直接影响.
- 含量,Ni价值状态,元素组成 (Ni,Mn,Co) 和Ni/Li障碍显著影响氧气的位置,含量和释放温度.
- 空位和高值状态之间的协同效应加剧了氧气不稳定性;LCSU中较高的含量导致更不稳定的氧气.
结论:
- 通过控制氧气的局部环境和稳定性来调整NMC的热稳定性.
- 了解Ni/Li混合效应至关重要:它降低了"Ni=Mn"组的稳定性,但通过形成超级交换链,提高了"富含Ni"的NMC.
- 和 doping 通过修改 Ni 价值状态,氧协调和 Ni/Li 障碍来调整 NMC 热稳定性的直接途径.
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