内在扭曲与Jahn-Teller扭曲相对应:高稳定性Na-Ion分层Mn-Rich氧化物阴极的新范式
Junteng Jin1, Yao Wang2, Xudong Zhao3,4
1Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing, 100083, China.
Angewandte Chemie (International ed. in English)
|February 5, 2025
概括
将氧气空缺引入富含的多层氧化物阴极,通过抵消Jahn-Teller扭曲来稳定离子电池,提高循环耐用性而不牺牲容量.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 储能 储能 储能 储能 储能 储能
背景情况:
- 富含的多层氧化物 (LMROs) 由于其高容量和低成本,对离子电池 (SIBs) 是有前途的阴极.
- 3+的Jahn-Teller (J-T) 扭曲导致结构降解,限制了LMRO阴极的实际应用.
研究的目的:
- 引入"对抗 J-T 扭曲的内在扭曲"机制以稳定 LMRO 阴极框架.
- 为了提高电网规模SIB的LMRO阴极的循环稳定性和性能.
主要方法:
- 系统地在LMRO中引入大量的氧气空缺.
- 使用同步射线X射线技术和原子尺度成像的先进表征.
- 理论计算以确认机制及其影响.
主要成果:
- 氧气空隙通过具有相反的变形方向来抵消J-T扭曲.
- 在ab平面和c轴上减少和均的格子应变.
- 减轻了P2-P'2相位过渡,并抑制了诸如边缘位移和裂之类的结构缺陷.
- 在500个循环后实现了91.9%的容量保留,其特定容量为P2-Na0.72Mg0.1Mn0.9O2.2. 在0.3°C下为186.5mAhg-1的P2-Na0.72Mg0.1Mn0.9O2.
结论:
- 通过氧气空隙的内在扭曲工程有效地稳定了LMRO阴极.
- 这种方法可以提高循环耐用性,而不会影响电化学性能.
- 为SIBs开发高性能LMRO阴极铺平了一条新道路.
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