调节可逆离子间隔的多层阴极材料中的伪约翰-泰勒效应和上层结构
Jiliang Zhang1, Jae-Bum Kim1, Jing Zhang1
1Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea.
Journal of the American Chemical Society
|April 25, 2022
概括
雅恩-泰勒效应 (JTE) 在分层阴极材料中引起应力. 伪JTE是一种二次效应,被认为是材料降解的关键因素,这表明它对提高电池性能的重要性.
科学领域:
- 材料科学
- 电化学
- 固态化学
背景情况:
- 雅恩-泰勒效应 (JTE) 是影响电化学循环过程中分层阴极材料应力的一个关键因素.
- 现有研究表明,即使在JTE消除后,原始层级材料中也存在上层结构痕迹和不可逆转的相变.
研究的目的:
- 研究伪JTE在分层阴极材料中的作用,特别是P2型Na3/4MnO2.
- 阐明伪JTE,阴离体扭曲和电化学降解之间的关系.
- 展示如何抑制伪JTE可以增强电化学性质.
主要方法:
- 使用泰勒膨胀来研究电离变形能量的理论分析.
- 对P2型丰富阴极 (Na3/4MnO2) 和其替代变体 (Na3/4(Li1/4Mn3/4) O2) 的实验研究.
- 先进的分析技术来描述结构扭曲和相位过渡.
主要成果:
- 伪JTE是一种二次JTE,被确定为不对称的MnO6八面体扭曲的广泛原因.
- 这些Na3/4(Li1/4Mn3/4) O2的扭曲导致了显著的电化学降解.
- 抑制伪JTE可以调节相位过渡并改善电化学性能.
结论:
- 伪JTE比传统的JTE在分层阴极材料中更为普遍和重要.
- 控制伪JTE为合理化以前的方法和提高分层阴极的稳定性和性能提供了新的途径.
- 这项工作强调了考虑伪JTE对于未来的阴极材料设计的关键重要性.
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