可進行重複充放電的鋰離子電池 (rechargeable lithium-ion batteries) 是可攜式電子產品中做為電源供應之不可或缺的角色。然而，鋰離子電池為高可靠度產品，意謂其衰變速度極為緩慢，因此如何精確推估鋰離子電池之壽命，對製造商而言是個十分重要的研究課題。過去針對高可靠度產品多是以固定應力加速衰變試驗進行分析，惟此方法的實驗成本通常相當昂貴。為彌補此缺點，本研究採用循環式逐步應力衰變試驗來收集鋰離子電池實驗資料，並以常用的逐步應力衰變模型 (如SS_ADT以及TSS_ATRP的模型) 為基礎，提出SS_ATRP模型來針對循環式逐步應力衰變試驗的資料進行分析，並使用最大概似估計法 (maximum likelihood estimation) 求出模型中的參數估計值以及預測正常使用狀況下之電池壽命EOP (end of performance)，配合有母數拔靴法 (parametric bootstrap) 計算其95% 信賴區間。最後則使用此實驗資料來推估鋰離子電池的平均失效壽命 (mean time to failure) 以及提出本研究的發展性。

Rechargeable lithium-ion batteries play an essential role as power supplies in portable electronic products. Due to its high reliability, the lifetime assessment for lithium-ion batteries is a challenging research topic. To address this issue, highly reliable products were often analyzed via constant stress accelerated degradation tests in practice. However, implementing such experiments is high-cost in general. To compensate for this shortcoming, this study designed a Type-III step-stress degradation test to collect the experimental data of lithium-ion batteries, in which different stresses are arranged in a cycle fashion. Adopting the ideas of SS_ADT, ATRP, and TSS_ATRP model, an SS_ATRP model is then proposed for analyzing the data collected from the Type-III step-stress degradation test. For inference, the maximum likelihood estimation is used for model fitting, under which the end-of-performance (EOP) of lithium-ion batteries is predicted at normal use conditions. The proposed methodologies are applied to the collected Type-III step-stress degradation test data for assessing the mean-time-to-failure (MTTF) of lithium-ion batteries. Finally, some possible extensions of this study are addressed.

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