Heating treatment of spent lithium-ion batteries and ammoniacal leaching of product of LiCoO2 reduced by carbon in vacuum
失效锂离子电池材料真空热处理及氨性浸出

The removal of organics from spent lithium-ion batteries,such as outer plastic shell and electrode membrane by vacuum distillation was studied.Battery-grade LiCoO2 was reduced by activated carbon using vacuum carbonthermal reduction method,and then the reduced mixture was leached in ammoniacal aqueous solution containing NH3 and NH4HCO3.Experimental results demonstrated that all the organics were removed at 450℃ under the vacuum pressure of 400 Pa.There was no reaction between LiCoO2 and carbon when heating temperature was below 400℃ under vacuum condition.Co and Li elements in the mixture of LiCoO2 and carbon were then transformed into CoO,Co and Li2CO3 phases at 600℃.Cobalt metal in cubic and hexagonal structures and a small amount of CoO were obtained at 800℃.The reduced product was easily leached out in the ammoniacal solution.Cobalt phases were dissolved into solution with leaching time up to 3 h,and the leaching ratio of lithium was above 97%.