一个策略,以减轻丰富的纳西康框架离子电池的Jahn Teller效应
Muhammad Tayyab Ahsan1, Zeeshan Ali1, Daping Qiu2
1School of Materials Science and Engineering, Peking University, Beijing, 100871, China.
Small (Weinheim an der Bergstrasse, Germany)
|August 19, 2024
概括
这项研究引入了一种基于的新型阴极材料用于离子电池 (SIB),可以克服Jahn-Teller效应的局限性. 新材料表现出高速率能力和卓越的周期稳定性,用于先进的能量存储.
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:
- 基于的超离子导体是对离子电池 (SIB) 的低成本阴极材料的有希望的.
- 3+的Jahn-Teller效应导致这些材料的低速率能力和低循环性能.
- 减轻Jahn-Teller效应对于开发先进的SIB阴极材料至关重要.
研究的目的:
- 为了合成一种新的无序和缺乏的纳西康材料,Na4-xMn (FeVCrTi) 0.25 (PO4) 3 (Na4-xMn (HE)),以抑制Jahn-Teller效应.
- 在基于的SIB阴极中实现高速能力和超稳定的电化学性能.
- 调查负责提高性能的潜在机制.
主要方法:
- 合成一个有障碍和缺乏的纳西康材料 (Na4-xMn(HE)).
- 电化学表征包括速率能力和周期性性能测试.
- 现场X射线衍射 (XRD),现场X射线光电子光谱 (XPS) 和第一原理计算来研究结构和电子性质.
主要成果:
- 合成的Na3.5Mn(HE) 材料呈现了五种可逆电子反应 (Ti3+/Ti4+,Fe2+/Fe3+,V3+/V4+,Mn2+/Mn3+,Mn3+/Mn4+).
- 在0.2°C达到141mAhg-1的容量,在1°C的500个循环后保持80%的容量,性能优于二元基材料.
- 对于Na3.5Mn(HE)//HC系统,在0.2°C时显示出89.7mAhg-1的完整电池容量.
结论:
- 缺乏,稳定的Na4-xMn(HE) 材料有效地弥补了Jahn-Teller效应,从而产生了优越的电化学性能.
- 该材料显示了用于SIB应用的增强动力学,结构可逆性和电子特性.
- 这项工作为设计高性能Mn基阴极用于储能提供了洞察力.
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