阴极/电解质间相的密度化以提高4.65V的LiCoO2的可逆性
Hengyu Ren1, Jiaxuan Hu1, Haocheng Ji2
1School of Advanced Materials, Peking University Shenzhen Graduate School, Peking University, Shenzhen, Guangdong, 518055, China.
Advanced materials (Deerfield Beach, Fla.)
|August 29, 2024
概括
研究人员通过添加氧沉积物,为氧化 (LCO) 电池开发了一种强化阴极/电解质介面 (CEI). 这种增强的CEI提高了电池在高电压下的稳定性和性能,为先进的LCO阴极开发提供了新的途径.
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
- 电池技术 电池技术
背景情况:
- 氧化 (LCO) 阴极在4.55V以上严重降解,限制了它们的高压性能.
- 阴极/电解质介相 (CEI) 形成和稳定背后的机制尚未完全理解.
研究的目的:
- 在LCO表面开发逐步加强的CEI,以提高高压稳定性.
- 阐明加强CEI的形成机制及其对电化学性能的影响.
主要方法:
- 用氧沉积物 (ZrO2和Li2ZrO3) 来改变LCO的表面,以产生Z-LCO.
- 在循环过程中CEI演变的现场调查.
- 在各种电压范围和速率下,对Z-LCO干电池进行电化学测试.
主要成果:
- 这种Zr-O沉积物促进了LiPF6的分解,形成了含有CEI的坚固且导电性的Zr-O-F物种.
- 加强的CEI稳定了表面晶格氧气,改善了Li+运输,并增强了相位过渡的可逆性.
- Z-LCO电池表现出良好的容量保留 (84.2%在1000次循环后在3-4.65V) 和速率能力 (160mAhg-1在16C).
结论:
- 使用Zr-O沉积物构建逐步加强的CEI的新策略已成功实施.
- 增强的CEI显著提高了LCO阴极的高压循环稳定性和速率性能.
- 这项研究为设计用于高能量密度电池的先进LCO材料提供了宝贵的见解.
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