缓慢释放的阴离子氧化还原活性促进了稳定的阴离子氧化还原和抑制了 Jahn-Teller 扭曲在分层的氧化物中的氧化
Ao Zeng1, Jianyue Jiao1, Hong Zhang1
1College of Materials Science and Optoelectronic Technology, Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS applied materials & interfaces
|January 31, 2024
概括
研究人员为离子电池开发了一种基于的新型阴极. 这种材料通过控制阳离子氧化还原反应来提高稳定性和容量,为先进的能量存储解决方案提供了一个有前途的途径.
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:
- 由于成本效益,基于的层氧化物对离子电池 (SIB) 是有前途的.
- 阳离子氧化还原反应 (ARR) 可以提高SIB容量,超出阴离子极限.
- 不稳定的ARR和Mn3+ Jahn-Teller扭曲导致SIB阴极的结构退化和容量衰减.
研究的目的:
- 设计和研究SIBs的P2型Na0.8Li0.2Mn0.7Cu0.1O2阴极材料.
- 了解基阴极中增强循环稳定的背后机制.
- 探索受控的阴离子氧化还原活性在抑制ARR期间有害影响中的作用.
主要方法:
- 一个P2型Na0.8Li0.2Mn0.7Cu0.1O2阴极的合成.
- 电化学测试包括200个周期在200mA/g的循环性能.
- 在现场的X射线衍射和多个现场表征.
- 密度函数理论 (DFT) 的计算.
主要成果:
- 纳0.8Li0.2Mn0.7Cu0.1O2阴极表现出极好的容量保留 (84.5%在200mA/g后200个循环).
- 增强的稳定性归因于阴离子氧化还原活性缓慢释放,抑制了Jahn-Teller扭曲.
- 支持ARR可逆性,得到了DFT计算的支持,显示抑制了层间迁移和减少了带间隙.
结论:
- P2型的Na0.8Li0.2Mn0.7Cu0.1O2材料显示出离子电池的卓越循环稳定性.
- 控制的阴离子氧化还原活性对于稳定阴离子氧化还原反应和防止结构降解至关重要.
- 这项工作为设计利用离子氧化还原活性的高能量密度阴极材料提供了洞察力.
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