自愈,Ga-Sb合金封闭的Sn阳极,用于稳定的纳离子储存在基于Glyme的电解质中
Dimpal Deori1, Madhurja Buragohain1, Youhyun Son2
1Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, India.
Small (Weinheim an der Bergstrasse, Germany)
|June 9, 2025
概括
一种具有锡 (Sn) 核心外结构的新型自愈抗氧化物 (GaSb) 合金使稳定的离子 (Na+) 储存成为可能. 这种先进的电极材料在以太基电解质中表现出良好的容量保留和循环寿命.
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
- 纳米技术纳米技术
背景情况:
- 开发稳定和高性能电极材料对于推进离子 (Na+) 电池技术至关重要.
- 锡 (Sn) 基材料在理论上具有较高的Na+储存能力,但其体积膨胀很大,周期寿命较短.
- 电极材料的自我愈合特性可以减轻循环过程中体积变化引起的降解.
研究的目的:
- 开发一种具有封闭的Sn核心外结构的自愈GaSb合金,用于增强Na+储存.
- 研究GaSb@Sn核心外材料的结构,电化学和机械性能.
- 了解Na+储存的机制以及核心外结构在提高稳定性方面的作用.
主要方法:
- 在碳支上合成GaSb@Sn核心外纳米结构.
- 使用高角度环状暗场扫描传输电子显微镜 (HAADF-STEM) 和电子能量损失光谱 (EELS) 的表征.
- 电化学性能评估,包括循环稳定性和速率能力.
- 在现场/操作的X射线衍射 (XRD) 和电化学扩展度研究.
- 密度函数理论 (DFT) 计算以探测电解质-电极相互作用.
主要成果:
- 该GaSb@Sn/C电极表现出高的特定容量 (560 mAh g-1在50 mA g-1和449 mAh g-1在2 A g-1),在1200和2000个周期内保持出色的容量.
- 操作XRD证实了Na+储存过程中Na-Sn,Na-Sb-O和Na-Ga-O金属间化合物的形成.
- 电化学扩展测量显示,与散装Sn (420%) 相比,电极膨胀显著减少 (33%),归因于GaSb外.
- DFT的计算显示了GaSb@Sn上的较弱的diglyme吸附,导致较薄的固体电解质介相 (SEI) 形成和更高的初始库伦比效率 (81%对比62%).
结论:
- 开发的可自我修复的GaSb@Sn核心外结构有效地适应Na+存储期间的体积变化,增强电极稳定性.
- 封闭的Sn结构和较弱的电解质相互作用有助于改善循环寿命和初始库伦比效率.
- 这种核心外架构为开发高性能和耐用的离子电池电极提供了一个有前途的战略.
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