Efficient Separation of Aluminum Foil and Cathode\nMaterials from Spent Lithium-Ion Batteries Using a Low-Temperature\nMolten Salt

Abstract

The\neffective separation of aluminum (Al) foil and cathode materials\nis a critical issue for the recycling of spent lithium-ion batteries\n(LIBs). Previous studies have shown that the strong binding force\nprovided by the organic binder polyvinylidene fluoride (PVDF) between\nthe cathode materials and the Al foil of spent LIBs makes it difficult\nto peel off the cathode materials from the Al foil, reducing the effectiveness\nof the metal recovery process. This study reports on a low-temperature\nmolten salt technology for melting the organic binder PVDF. The results\nshowed that an aluminum chloride-sodium chloride (AlCl₃-NaCl) systema nontoxic reaction mediumcould melt\nPVDF efficiently and is environmentally friendly as well, because\nof the phase transformation of molten salt caused by heat storage.\nThe optimal conditions for peeling off cathode materials were a temperature\nof 160 °C, molten salt:cathode electrode mass ratio of 10:1,\nand holding time of 20 min. The highest peeling off percentage of\ncathode materials was 99.8 wt %. The purpose of this study was to\nprovide an environmentally friendly, low-cost, and effective solution\nfor the separation of cathode materials and Al foil from spent LIBs.