Over the last few decades, Lithium-ion (Li-ion) batteries have attracted significant attention due to their high energy density, low maintenance, and variety of shapes, chemistries, and performances available. Meanwhile, the concept of reliability and safety assessment of the Li-ion batteries have become essential issues for Original Equipment Manufacturers (OEMs). Evaluation of reliability plays a critical role in assessing overall a Li-ion battery behaviour over its lifespan. The primary gap definition of the reliability assessment of Li-ion batteries are i: Reliability indicators and their connection with degradation modes, degradation mechanisms, and degradation conditions, ii: Multi degradation conditions (different temperatures and C-raters) need to implement on the Li-ion batteries to investigate their effect on the reliability indicators, iii: The reliability assessment of the Li-ion battery from the time-domain, iv: Investigation of degradation conditions and their comparison from the reliability standpoint.
To fulfil these objectives, capacity fade, power fade, and battery open-circuit voltage (OCV) variations have been introduced as three main reliability indicators in this dissertation. Moreover, quantitative technique and risk analysis have been taken into account for providing reliability assessment as solutions to existing challenges from the time domain. Additionally, Nickel Manganese Cobalt Oxide (NMC) cylindrical Li-ion battery due to high domain operating temperature and discharge C-rate has been used to cover the evaluation from different degradation conditions. Also, due to the nonlinear behaviour of the Li-ion batteries, power fade and OCV variations in three critical State of Charge (SoC) windows (80%, 50%, and 20%) have been evaluated. The main objectives of this dissertation are summarized as below: