Scope and relevance of circular economy indicators for the sustainable lifetime management of batteries for electric vehicles

Circular economy (CE) is aimed at improving resource efficiency to reduce the environmental burden and other negative externalities of production and consumption systems. Focusing on batteries for electric vehicles (EV), various CE strategies can be applied to improve manufacturing efficiencies, develop long-lived products or facilitate life-extension, and enable material reuse and recycling at the end-of-life. However, product design methods not relying on the consideration of CE criteria and indicators could lead to insufficient resource efficiency improvements or undesired consequences, such as rebound effects. This is important because batteries can account for over 40% of the EVs´ life cycle environmental impacts. However, the literature analysing the applicability of CE indicators to EV battery design and management is scarce and limited in scope. This study evaluates 15 product-level CE indicators to determine its importance and viability to inform battery designers and manufacturers in the development of more sustainable products. An Excel-based matrix was built to provide a description of each CE indicator, including its applicability, scoring system and data requirements, and show their links to the hierarchy of CE strategies and life cycle stages. The suitability of the CE indicators to support decision-making was evaluated by ten industrial stakeholders (manufacturers of battery components). The results show that End of Life Indices (Favi et al., 2016) and the Product Circularity Indicator (Bracquené et al., 2020) are the most suitable indicators due to the quality of information provided. However, it is crucial to develop new battery-oriented circular design methods and indicators to support the development of sustainable EV batteries.