Hydrometallurgical Regeneration of LiMn 2 O 4 Cathode Scrap Material and Its Electrochemical Properties

Abstract The main researches focus on the recovery of metal elements in lithium manganate and not consider regenerating the cathode scrap materials. In this study, first, the polyvinylidene fluoride (PVDF) binder is removed by a combination of solvent dissolution and heat treatment. PVDF is easily separated by dissolving in an N ‐methyl‐2‐pyrrolidone solution at a heating temperature of 60 °C, stirring time of 50 min, and solid solution ratio of 80 g⋅L −1 . The dissolution rate of the scrap material achieves 86.70 % under optimal conditions. Further, using inductively coupled plasma spectroscopy to define the Li and Mn metal contents, and the LiMn 2 O 4 cathode material is regenerated by a hydrometallurgical method. At the optimum calcination conditions of 500 °C for 12 h, electrochemical performance show that there are obvious charge and discharge platforms in the charge/discharge curves, and high first‐cycle discharge capacity is 123.7 mAh g −1 (3.0–4.3 V and 0.1 C), after 50 cycles, it decrease to 83.2 mAh g −1 .