Dissolution of cathode active material of spent Li-ion batteries using tartaric acid and ascorbic acid mixture to recover Co

•Tartaric and ascorbic acid mixture can dissolve active cathode material of spent Li-ion batteries.•Formation of Co(III)- and Co(II)-L complex was evident from UV–vis spectra.•Co was recovered as Co(II)-oxalate by selective precipitation.•Unlike mineral acids, these organic acids are advantageous in waste management.

Environmentally benign hydrometallurgical dissolution process is investigated for the recovery of cobalt from the cathode active materials of spent lithium-ion batteries (LIBs). A mixture of tartaric acid and ascorbic acid is used to dissolve the LiCoO2 collected from spent LIBs. The reductive-complexing mechanism led to > 95% dissolution with 0.4 M tartaric acid and 0.02 M ascorbic acid in about 5 h at 80 °C. The dissolved Co was separated as cobalt oxalate from the mixture.

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