Steel-based Laminates for Lithium-ion Pouch Cell of Electric Vehicles

Aluminium foils have gained traction with EV battery manufacturers for their pouch cell format. Over the years it has evolved as a material of choice, but it is still plagued by issues of stress concentration, swelling due to lower strength and stiffness of base aluminium layer. Preliminary investigation revealed that laminates using steel foil material (thickness <0.1mm) could be a potential candidate for EV pouch cell casing. Thus, steel-based laminate was developed meeting key functional requirements (e.g. barrier performance, insulation resistance, peel strength, electrolyte resistance, formable without cracking at edges, and heat sealing compliant). This innovative patented steel-based laminate was further used to manufacture pouch cell prototypes (maximum capacity 2.5Ah) for key performance tests (e.g. cell cycling, nail penetration and thermal runaway). The study paves the way for a low cost, sustainable and flexible yet strong steel-based laminate packaging material solution for lithium-ion pouch cells.