This work utilizes in situ transmission electron microscopy–based nanopillar compression to investigate the effect of electrochemical cycling on the mechanical properties of LiCoO₂. The ultimate strength of LiCoO₂ in the pristine state, and after 1 and 11 cycles are 5.62 ± 0.22 GPa, 3.91 ± 1.22 GPa, and 2.27 ± 1.07 GPa, respectively. The reduced average yield strengths and the large standard deviations of cycled samples, relative to the pristine powder, are hypothesized to result from nonuniform accumulation of Li⁺ site‐point defects during cycling; either H⁺ or Li⁺ vacancies. Density functional theory calculations support our hypothesized link between a nonuniform Li site‐point defect distribution in the cathode and reduction in the materials cohesive strength.

中文翻译：

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电化学循环对LiCoO2强度的影响

这项工作利用基于原位透射电子显微镜的纳米柱压缩技术来研究电化学循环对LiCoO ₂力学性能的影响。在原始状态下以及1和11个循环后，LiCoO ₂的极限强度分别为5.62±0.22 GPa，3.91±1.22 GPa和2.27±1.07 GPa。相对于原始粉末，循环样品的平均屈服强度降低和标准偏差大，据推测是由于循环过程中Li ⁺点缺陷的不均匀积累引起的。H ⁺或Li ⁺空缺。密度泛函理论的计算支持了我们假想的阴极正极点缺陷分布与材料内聚强度降低之间的假想联系。