Development of Lightweight, Sustainable and Multifunctional Battery Pack Materials in Electric Vehicles

Abstract

Accelerated needs for battery electric vehicles (BEVs) drive materials requirements toward lightweight, mechanically stable, and environmentally friendly battery packaging materials beyond metal-rich systems. This thesis explores the GO/rGO polymer coatings as multifunctional layers for two packaging sectors, namely, CF skins for battery enclosure and PA/PE films for pouch laminates. A focused literature benchmark is supplemented with experiments performed on coated CF and PA/PE coupons at 1, 3, and 5 wt% graphene loadings. Performance was characterized via peel load–displacement (interfacial adhesion and failure mode), tensile testing (mechanical integrity of coated substrates) and a 48 h deionized-water soak (moisture stability). Results demonstrate that low-to-moderate loadings (1-3 wt%) provide robust adhesion and mechanical performance on both CF and PA/PE, whilst coatings remain stable after soaking. On the other hand, 5 wt% early debonded, synergetic particulate detachment and worse mechanical behavior, indicating interfacial instability. Such results bring valuable design guidelines to metal-lean/metal-free battery packaging: constraining graphene in a 1–3 wt% window and adopting graded coatings (less loading on adhesion-critical interfaces, moderate loading on reinforcing or tortuosity-barrier sites). This route enables lightweight CF enclosures and metal-free pouch laminates, which are in line with the sustainability targets. The leading nextstep priorities are quantitative WVTR/OTR, electrolyte ageing and thermal/abuse propagation studies, as well as life-cycle analysis (LCA) and scalability considerations.