关于应变和电荷状态与电池阴极材料LiCoO中的离子扩散相互作用的第一原则研究 LiCoO2
Zizhen Zhou1,2, Claudio Cazorla3, Bo Gao2,4
1Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
ACS applied materials & interfaces
|November 9, 2023
概括
机械应变显著影响离子电池阴极性能. 压缩应变增强了LiCoO2中的Li+扩散,而拉伸应变和压力阻碍了它,为改善能量密度提供了洞察力.
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
- 计算物理 计算物理
背景情况:
- 在离子电池 (LIB) 中的阴极降解限制了能量密度.
- 由充电状态 (SOC) 和接口不匹配影响的结构应变是主要的降解因素.
- 了解对正极性能的机械影响对于先进的电池设计至关重要.
研究的目的:
- 研究双轴应变和水静压对LiCoO2 (LCO) 结构和Li+运输的影响.
- 澄清机械应力,SOC和阴极材料特性之间的关系.
- 为提高LIB能量密度提供见解.
主要方法:
- 第一原则计算.第一原则计算.
- 裸体弹性带技术.
- 分子动力学模拟.分子动力学模拟.
- 分析结构参数和空缺的形成能量.
主要成果:
- 压缩双轴应变增强了缺乏的LCO中的Li+扩散性.
- 拉力双轴应变和水静压抑制了Li+扩散.
- +扩散与"Co层距离"相关,而不是"层距离".
- 在水静压下首次报告LCO激活体积.
- 压缩应变削弱了Li-O键,可能降低了Li的间隙潜力.
结论:
- 机械应变极大地影响LCO阴极中的Li+扩散动力学.
- 应变工程为优化阴极性能和能量密度提供了一条途径.
- 结果提供了更深入的理解机械电化学合在LIBs.
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