通过局部化学乱优化氧氧还氧活性,以实现具有高压稳定性的强大的Co-Free丰富阴极
Hongfei Zheng1, Mengjian Fan2, Chenying Zhang2
1College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang Province, 310027, China.
Advanced materials (Deerfield Beach, Fla.)
|November 27, 2024
概括
在丰富的阴极中优化晶格氧氧还原 (LOR) 是至关重要的. 这项研究表明,过度的LOR活动,而不仅仅是不足,会损害稳定性,确定86%的LOR是持久电池性能最佳的.
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:
- 丰富阴极中的晶格氧氧还原 (LOR) 提供了高容量,但面临着稳定性挑战.
- 了解LOR活动对结构和电化学稳定性的确切影响是进步的关键.
研究的目的:
- 为了调节Co-free Li-rich 阴极中的LOR活动.
- 阐明LOR活动,结构演变和电化学稳定性之间的关系.
- 为了确定最佳的LOR活动以提高电池性能.
主要方法:
- 在Li1+xMn0.62Ni0.18O2阴极中控制局部化学干扰,以调整LOR活动从22%到92%.
- 在不同的LOR度下研究了结构演变和电化学性能.
- 分析了故障机制,特别是格子应变效应.
主要成果:
- 证明过度抑制和过度LOR活动都会对稳定性产生负面影响,挑战传统观点.
- 在Li1.18Mn0.62Ni0.18O2 (LR-78) 中确定了86%的最佳LOR活性.
- 在400个循环 (1C) 和稳定的高速循环 (600个循环在5C) 后,LR-78实现了96%的电压保留.
结论:
- LOR活动的程度极大地影响着阴极稳定性,并确定了最佳范围.
- 这些发现为LOR机制和故障模式提供了新的见解,指导了稳定的丰富阴极的设计.
- 这项工作为开发耐用LOR基阴极用于先进的能量存储提供了关键指导.
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