The cyclic plasticity behaviour and failure mechanism of the cathode material in lithium-ion batteries urgently need to be understood due to the cyclic lithium-ion diffusion-induced stress during charging-discharging process. Many researches have focused on the shakedown and ratcheting responses of lithium-ion battery anode. However, the systematic investigation on the plasticity behaviour of lithium-ion battery cathode is still lacking. In this paper, the cyclic plasticity behaviour of LiNi_xMn_yCo_zO₂ electrode subjected to cyclic lithiation/delithiation under a constant mechanical load is investigated comprehensively. The shakedown, ratcheting and fatigue analyses of active layer are conducted using direct numerical techniques based on the Linear Matching Method framework, while coin cell electrochemical experiments are performed simultaneously to support the analysis. The effect of thickness of coating on the shakedown and ratcheting response is investigated, and the thickness is confirmed as a crucial parameter that can influence the battery performance. The strain-fatigue life curve is also obtained to effectively predict the life of active coating. Moreover, the numerical results reveal the existence of low cycle fatigue at the centre, and ratcheting mechanism on the edge of the cathode, which is consistent well with the experimental result.

由于在充放电过程中循环锂离子扩散引起的应力，迫切需要了解锂离子电池中正极材料的循环可塑性行为和破坏机理。许多研究集中在锂离子电池负极的震动和棘轮响应上。但是，仍然缺乏对锂离子电池正极可塑性行为的系统研究。本文研究了LiNi _x Mn _y Co _z O ₂的循环可塑性行为全面研究了在恒定机械载荷下经受周期性锂化/脱锂的电极。基于线性匹配方法框架，使用直接数值技术对活性层进行了减振，棘轮和疲劳分析，同时还进行了纽扣电池电化学实验以支持该分析。研究了涂层厚度对震动和棘轮响应的影响，并确定厚度是影响电池性能的关键参数。还获得了应变疲劳寿命曲线，以有效预测活性涂层的寿命。而且，数值结果表明，在中心处存在低循环疲劳，并且在阴极边缘处存在棘轮机制，