在较高的电流速率下实现高度可逆的Nb5+/Nb4+/Nb3+ 在散装NASICON-NaNbAlPO中进行氧化反应
Ayon Phukan1, Biplab Patra1, Tanushree Acharya2
1New Chemistry Unit, International Centre for Materials Science, and School of Advanced Materials, Jawaharlal Nehru Centre For Advanced Scientific Research, Bangalore, Karnataka, India.
Small (Weinheim an der Bergstrasse, Germany)
|February 4, 2026
概括
替代的纳西康阳极 (NaNbAl) 能够使离子电池具有高度可逆的Nb氧化还原反应. 这种稳定结构提高了循环稳定性和快速离子传输,为先进的能量存储铺平了道路.
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
- 固态化学 固态化学
背景情况:
- 离子电池 (SIB) 对大规模储能充满希望.
- 纳西康类型的材料,特别是Nb2(PO4) 3,由于Nb氧化还原的高理论容量,显示出作为SIB阳极的潜力.
- 结构性降解限制了传统NASICON阳极中Nb氧化还原反应的可逆性.
研究的目的:
- 为SIBs开发一个具有增强结构稳定性和可逆Nb氧化还原反应的NASICON阳极.
- 调查Al替代在稳定纳西康框架和促进Na+ (de) 干扰中的作用.
- 评估新型NaNbAl阳极的电化学性能和离子传输特性.
主要方法:
- 基于密度函数理论 (DFT) 的计算,以了解氧化还原机制和离子迁移障碍.
- 散装NASICON-NaNbAl(PO4)3 (NaNbAl) 阳极材料的合成和表征.
- 电化学测试,包括循环性能,速率能力和操作同步射线X射线衍射 (XRD).
主要成果:
- 在NaNbAl中Al的替代稳定了NASICON框架,使可逆Nb5+/Nb4+/Nb3+氧化还原反应成为可能.
- NaNbAl阳极在5C时表现出90mAhg-1的容量,在1000个循环后保持86%的容量.
- 操作的XRD和DFT计算证实了Na+结构中的快速Na+ (de) 间位和低迁移障碍.
- 一个完整的SIB电池 (Na4V2(PO4) 3下载NaNbAl) 的能量密度为201 Wh kg-1 (阴极质量),在1C的200个周期内保持84%的容量.
结论:
- 替代NASICON (NaNbAl) 是用于离子电池的高度可逆性阳极材料.
- 稳定的框架和促进的离子扩散使得强大的循环性能和高速率能力.
- 这项工作为设计先进的NASICON阳极提供了一个可行的策略,利用可逆的多电子氧化还原对.
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