降低的债券共价性和无异型格子扭曲使混合聚离子阴极中的高Fe-Mn回氧激活成为可能
Huangxu Li1,2, Xu Wang3, Fangyan Liu4
1Key Laboratory of Silicon-based Materials, the Ministry of Education, and School of New Materials and New Energy, Fujian Fuyao University of Science and Technology, Fuzhou 350109, P. R. China.
ACS nano
|October 3, 2025
概括
这项研究揭示了一种新的离子电池阴极材料,Na4Mn1.5Fe1.5(PO4)2(P2O7),它克服了 Jahn-Teller 效应等限制,提高了循环稳定性和能量密度.
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:
- 基于铁 (Fe) 和 (Mn) 的聚离子化合物是离子电池 (SIB) 的成本效益高的阴极材料.
- Fe2+/3+的低氧化还原潜力和Mn2+/3+中的Jahn-Teller (JT) 效应阻碍了氧化还原激活,限制了SIB中的循环稳定性和速率性能.
研究的目的:
- 调查Fe-Mn氧化还原激活和晶格扭曲在SIBs的新型聚离子材料中的协同效应.
- 提高储存材料的能量密度,速度能力和循环稳定性.
主要方法:
- 合成和表征Na4Mn1.5Fe1.5(PO4)2(P2O7) (NMFPP) 材料的合成和表征.
- 实验和理论研究 (例如,DFT) 来分析氧化还原行为,电子结构和离子扩散.
- 电化学测试用于评估电池性能.
主要成果:
- 在NMFPP中实现了高Mn2+/3+和Fe2+/3+氧化还原激活.
- 替代减少了Fe-O键的共价性,增加了Fe2+/3+氧化还原潜力和能量密度.
- 不同类型的晶格扭曲扩大了Na+扩散通路,降低了快速Na+迁移的障碍.
- NMFPP表现出增强的能量密度,速度性能和卓越的循环稳定性.
结论:
- 雅恩-泰勒效应和晶格扭曲可以协同增强电极材料中的过渡金属氧化还原激活.
- 这项工作为设计用于离子电池的高性能阴极材料提供了洞察力.
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