A Mixed-Methods Approach to Identify and Assess Sustainability Criteria for Battery Chemistries in Electric Vehicles

Sammanfattning

The transport system is currently undergoing a transition, with car manufacturers shiftingfrom producing conventional internal combustion engines to producing electric vehicles(EVs). One of those actors is Volvo Car Corporation, which has the ambition to becomea fully electric car manufacturer by 2030, as well as climate neutral and circular by 2040.One important factor to assess in the transition to EVs is the choice of battery cell chemistry.The aim of this study is to identify and assess sustainability criteria for multiple lithiumionbatteries (LIBs) and sodium-ion batteries (SIBs) chemistries for EV application. TheLIB cell chemistries examined are nickel manganese cobalt - graphite (NMC811-Gr) andlithium iron phosphate - graphite (LFP-Gr), and SIB cell chemistries are nickel manganesemagnesium titanium oxide - hard carbon (NaNMMT-HC) and nickel manganesecobalt oxide - hard carbon (NaNMC-HC).Prior research within sustainability in battery cell chemistries for electric vehicles hasoften been covered through life cycle assessments (LCA) studies. However, LCA hasbeen shown to only address limited aspects of sustainability. This thesis proposes amixed-methods approach to assess sustainability, by combining an open space technology(OST) workshop, data from LCAs, expert interviews, and multi-criteria decision analysis(MCDA), in order to bring forward other aspects in the sustainability assessment.The sustainability indicators identified in the OST workshop and used in this study are’Responsible sourcing and social aspects’, ’Human health’, ’Raw material availability’,’Longevity of cell’, ’Climate impact’, and ’Recyclability’. Quantification of the indicatorsand the MCDA showed that the LFP-Gr cell is a promising chemistry amongst thoseassessed.In conclusion, it is recommended to adopt additional stakeholder perspectives, and othertools, to complement the environmental and social assessments conducted using LCAstudies, when assessing the sustainability of both current and emerging battery chemistries.