在离子电池的Ni和Co无基阴极化学中混合离子和阴极氧化
Sudhan Nagarajan1, Sooyeon Hwang2, Mahalingam Balasubramanian3
1Department of Mechanical Engineering, Wayne State University, Detroit, Michigan 48202, United States.
Journal of the American Chemical Society
|September 15, 2021
概括
研究人员开发了新的基于硫的阴极,用于改进的离子电池. 这种方法通过利用混合的阳离子和阴离子氧化还原反应来提高稳定性和容量,超越了传统的金属氧化物.
科学领域:
- 材料科学
- 电化学
- 固态化学
背景情况:
- 离子电池的常规层氧化物阴极面临理论容量限制.
- 电流阴极中的离子氧化还原反应由于金属-氧联体共价性较弱而导致稳定性问题.
研究的目的:
- 在正极材料中探索改进的金属联体共价性.
- 通过硫合并利用可逆混合阳离子和阴离子氧化还原化学.
- 开发用于先进的离子电池的新型稳定阴极材料.
主要方法:
- 在阴极框架中引入硫作为较少的电子负连接体.
- 用Fe氧化还原对合成和表征层状阴极材料 (Li2SnS3).
- 使用电子能量损失光谱 (EELS) 和X射线吸收近边结构 (XANES) 进行电荷分析.
- 使用高分辨率传输电子显微镜 (HRTEM) 和高角度环状暗场扫描传输电子显微镜 (HAADF-STEM) 进行结构分析.
主要成果:
- 通过结合硫,证明了增强的金属配体共价性.
- 在新材料中确定可逆混合阳离子和阴离子氧化还原化学物质.
- 在循环过程中观察到结构变化,表面无形化和纳米孔形成.
- 提供了关于提取过程中金属和配体位点的电荷贡献的见解.
结论:
- 成功设计了一种使用硫的新型分层阴极材料.
- 这项研究为开发无Ni和无Co的石墨烯阴极提供了途径.
- 这些发现为基于基的双氧还原阴极的先进功能材料铺平了道路.
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