在现场原子级观测电化学脱诱导结构 运行全固态电池中的LiCoO2阴极的演变
Yue Gong1,2, Jienan Zhang1, Liwei Jiang1
1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
Journal of the American Chemical Society
|March 10, 2017
概括
我们开发了一种新方法来观察固态电池在运行过程中的原子变化. 这项研究揭示了氧化物正极如何转化为纳米晶体,为改进电池设计提供了洞察力.
科学领域:
- 材料科学
- 电化学
- 纳米技术
背景情况:
- 与传统离子电池相比,全固态电池 (ASSB) 提供了更高的安全性和能量密度.
- 了解ASSB中的原子级动态过程对于优化其性能至关重要.
- 电极材料的电化学脱是影响电池降解和容量衰减的关键过程.
研究的目的:
- 在ASSB中开发和应用一种新的原子级观测方法.
- 在原子水平上研究LiCoO2阴极在脱过程中的结构演变.
- 阐明离子迁移路径和颗粒边界在非化阴极中的作用.
主要方法:
- 使用基于芯片的现场传输电子显微镜 (TEM) 持有器进行原子尺度成像.
- 采用聚焦离子束 (FIB) 研磨来准确制备ASSB的样本.
- 在偏差校正扫描TEM (STEM) 中构建并运行由LiCoO2阴极,LLZO固体电解质和黄金阳极组成的ASSB.
主要成果:
- 在高压脱过程中观察到原始单晶LiCoO2转化为纳米大小的多晶体.
- 确定了脱阴极内连贯双边界和反相域边界的形成.
- 理论计算证实,在离子提取后,颗粒边界变得更加有利.
- 在阴极多晶化之前和之后提出了不同的迁移途径.
结论:
- 液态电解质电池中的LiCoO2在原子尺度上的结构演变与液态电解质电池的结构演变有很大不同.
- 谷物边界工程和理解迁移对于设计高性能ASSB至关重要.
- 在现场开发的TEM方法为推进电池材料研究提供了前所未有的机械洞察力.
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