Decomposition of PVDF to delaminate cathode materials from end-of-life lithium-ion battery cathodes

The growing demand of electric vehicles and rapid consumption rechargeable lithium-ion batteries (LIBs) require recycling spent cathode active materials (CAMs) to reduce hazardous wastes supply raw LIB production. To separate CAMs from the cathode, direct calcination polyvinylidene fluoride (PVDF) binder is widely applied, which leads high energy release toxic hydrogen fluoride. It desirable have an environmentally friendly effective alternative traditional calcination. In this study, five lithium salts, LiOAc (lithium acetate), LiNO3, LiCl, Li2CO3, Li2SO4, were deployed compared for their performance in CAMs. A peel-off efficiency up 98.5% was achieved at a LiNO3 molar ratio 3:2, salt mass 10:1, temperature 300 °C holding time 30 min. This system avoids corrosive chemicals minimizes particle agglomeration recycled products. Compared with sodium systems (NaOAc-NaNO3) or calcination, LiOAc-LiNO3 prevented reaction further loss, minimized crystal structure morphological changes. decomposition mechanism PVDF through adsorption HF fluorine substitution proposed.