Second Life Applications for Degraded EV Batteries : Evaluating Benefits Basedon Remaining Useful Life and Battery Configurations

Abstract: This thesis explores the potential of second-life electric vehicle batteries, which are no longer suitable for electro-mobility, to provide energy storage solutions. The study iden- tifies two potential applications for second-life batteries: charging stations and residential PV energy storage systems. The research uses the remaining useful life as a vital indicator of the benefit that emerges from each solution. A battery aging framework is proposed, tak- ing power demand and temperature as inputs and generating capacity loss and resistance increase utilizing aging models from the literature. It is observed that the prediction can vary significantly depending on the model. Additionally, the total costs of each solution are heavily influenced by the battery pack configuration, as EV batteries can be directly reused or refurbished. A lower degree of dis-aggregation and testing is more cost-effective and entails fewer wasted components, yet it introduces performance uncertainties. The study concludes that applications that can tolerate uncertainties and inflexibility are best suited to meet the supply of second-life EV batteries. Furthermore, by re-purposing second-life batteries, there is potential to maximize their value and reduce environmental impact by reducing the need for new batteries.