Cleaner recycling of cathode material by in-situ thermite reduction

The extensive application of lithium-ion batteries (LIBs) generates a large amount of hazardous spent LIBs, for which sustainable recycling is seriously required by the demand of both environmental protection and resources conservation. An environmental friendly, economic effective and industrial applicable process has been developed for spent LiNixCoyMnzO2 (x + y + z = 1) cathode recycling. Here, the current collector of aluminium preforms as the in-situ reductant of thermite reduction transforming valuable metals in LiNixCoyMnzO2 cathode into LiAlO2, Li2O, NiO, CoO, and MnO. Then, Al in the in the thermite reduction product can be removed by alkaline leaching without large amount of explosive H2 emission. Afterwards, valuable metals of Li, Ni, Co, and Mn were effectively leached into H2SO4 solution with leaching efficiencies of 99.78%, 98.62%, 99.29% and 99.91%, respectively. Comparing with the traditional carbothermic reduction methods, this method enjoys advantages of no need for peeling off the cathode materials, none adding of carbonaceous materials, avoiding large amount of H2 emission and lower reduction temperature. The in-situ thermite reduction process demonstrates a greener, simpler, safer, more energy conserving and industrial applicable approach for sustainable recycling of spent LIBs.