Regeneration of waste LiCoO₂ cathode materials with high energy stripping of laser

To regenerate waste LiCoO₂, laser was used to strip LiCoO₂ from the current collector. The surface chemical state and element composition of the laser stripped LiCoO₂ material were analyzed. The regenerated laser-stripped LiCoO₂ was used to fabricate the cathode of batteries and the electrochemical performance was tested. The test results show that the first discharge specific capacity of the regenerated LiCoO₂ is 164.6 mAh g⁻¹ at 25 mA g⁻¹, and capacity remains 120 mAh g⁻¹ after 100 cycles. At high current density of 1250 mA g⁻¹, its capacity can be stabilized at 97.2 mAh g⁻¹. The excellent electrochemical performance can be attributed to the high energy of the laser which can directly decompose and volatilize PVDF and C, thereby effectively improves the purity of LiCoO₂. Moreover, the laser could effectively decompose Li_xCoO₂ to Li₁CoO₂ and Co₃O₄ by heating, which facilitates the reaction of Co₃O₄ with Li₂CO₃ to form LiCoO₂ during the process of replenishing lithium, therefore, improves the structural stability and dynamic performance of the regenerated LiCoO₂.