Abstract:
Lithium ion batteries (LIBs) are being used in communication and transportation vehicles for last 30 years. LIBs has become an essential alternative resource for its high contents of worthwhile components like lithium and cobalt. After use, batteries are getting accumulated at dumping sites globally, causing fires at dump sites, pollution in soil and water streams. In this research, a hybrid process was developed with citric acid as leaching agent and hydrogen peroxide (H2O2) as a reductant for recovery of lithium and cobalt element from waste mobile phone LIBs. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), X-Ray Diffraction (XRD) and Energy Dispersive Spectroscopy (EDS) were used to analyze the elemental contents. The results exhibited 90.20% of cobalt and 93.46% of lithium leaching efficiency under optimized conditions with concentrations of 1 molar Citric acid, H2O2 content of 3 vol.%, solid to liquid ratio of 20 g L-1, leaching temperature of 80 °C and reaction time of 2 h. Leached cobalt and lithium ions were converted into cobalt oxalate and lithium carbonate using oxalic acid and sodium carbonate with a recovery efficiency of 95% and 91% with sample purity of 99.72% and 98.77%, respectively. Recovered products have high market value of cobalt oxalate worth Rs 12,000/kg and lithium carbonate worth Rs 10,000/kg in the Pakistani chemicals market. Cobalt oxalate is used in the synthesis of cobalt powder, desiccants, additives, ceramics, pigments, foam, stabilizers, catalysts, in cobalt oxide preparation and for the production of cathode active material. Lithium carbonate is used as a catalyst, lithium salt, ceramic material, dental material, swelling joint therapy material and in the reduction of critical psychological disorders. The developed hybrid process was found efficient, low cost, easy to handle and environmentally safe.
