结构相容的阳离子替代增强NASICON-Na4Mn1.5Fe1.5(PO4)2P2O7阴极
Jingyao Zeng1, Lei Sun1, Jinqiang Gao2,3
1College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
ACS nano
|September 8, 2025
概括
在离子电池阴极中的离子替代提高了性能. 在Na4Mn1.5Fe1.5(PO4)2P2O7中用酸盐取代酸盐可以提高离子的移动性和结构稳定性,从而更好地储存能量.
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:
- 离子电池 (SIB) 是离子电池的一个有希望的替代品.
- 像Na4Mn1.5Fe1.5(PO4)2P2O7 (NMFPP) 这样的聚离子框架提供高能量密度,但受到Na+流动性和结构稳定性的损害.
- 在NMFPP中整合 (Mn) 提高了能量密度,但加剧了Na+扩散问题和Jahn-Teller效应.
研究的目的:
- 为了提高NMFPP阴极的离子 (Na+) 流动性和结构稳定性.
- 调查阴离子替代对NMFPP电化学性能的影响.
- 为SIBs开发一种高性能阴极材料.
主要方法:
- 阳离子替代策略:部分替换PO4(3-) 用SiO4(4-) 组.
- 合成的Na4Mn1.5Fe1.5(PO4)1.95(SiO4)0.05P2O7.5的合成情况
- 电化学表征包括静电间歇定位 (GITT) 和电化学阻抗光谱 (EIS) 通过DRT分析.
- 使用*in situ*X射线衍射 (XRD) 的结构分析.
主要成果:
- 加入SiO4(4-) 导致了格子扩张,促进了Na+扩散,并降低了电荷-放电阻抗.
- 由于的电子负性较低,观察到更好的循环稳定性,允许更好的电荷再分配和减少格子体积波动.
- 修改后的阴极在1°C的500个循环中保持了85.42%的容量,在5°C的1500个循环中保持了80.54%.
结论:
- 阴离子替代是优化SIB阴极中的多阴离子框架的有效策略.
- Na4Mn1.5Fe1.5(PO4)1.95(SiO4)0.05P2O7阴极表现出增强的速度能力和长期循环稳定性.
- 这种方法在开发先进的离子电池材料方面具有重大潜力.
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