Recycling of spent lithium-ion batteries is an urgent task in view of the resource shortage and environmental concerns. Pretreatment as the first step in recycling of spent lithium-ion batteries has become urgent issue for efficient separation of spent cathode materials from aluminum foil. Herein, a facile ternary molten salts approach is presented for efficient separation of cathode material and aluminum foil synchronous implementation of regeneration of spent cathode material. The separation efficiency reaches 99.98% at molar ratio of LiNO3: LiOH·H2O: Li2CO3(LNOC) of 3:2:0.5 with mass ratio of spent cathode pieces to the ternary molten salts of 1:2 holding at 300 °C for 15 min. The regenerated materials show discharging capacity of 122.2 mAhg−1 at 1C with retention rate of 99.97% after 100 cycles. The ternary molten salts are also made available for separation of other spent cathode materials with achieving high separation efficiency.