Effective and environmentally friendly recycling process designed for LiCoO2 cathode powders of spent Li-ion batteries using mixture of mild organic acids

An effective and environmentally friendly recycling process designed for LiCoO2 cathode powders of spent Li-ion batteries using mixture of mild organic acids, citric acid (CA), tartaric acid (TA) and ascorbic acid (AA), to recover the metals. Almost complete dissolution of Li and nearly 90% dissolution of Co occurred in at 80 °C for 6 h. The reducing agent, ascorbic acid (AA), converts the dissolved Co(III) to Co(II) thereby selective recovery of Co as Co(II)-oxalate is possible. The formation of Co(III)-and Co(II) complex is evident from the UV-Vis spectra of the dissolved solution as a function of dissolution time. Thus, the reductive-complexing dissolution mechanism is proposed here. These mild organic acids are environmentally benign unlike the mineral acids.