Chlorinated polyvinyl chloride (CPVC) assisted leaching of lithium and cobalt from spent lithium-ion battery in subcritical water

The objective of this study was to determine leaching efficiency of Li and Co from spent lithium-ion batteries (LIBs) by using waste chlorinated polyvinyl chloride (CPVC) in hydrothermal subcritical water process. Waste CPVC was used as the source of HCl to speed up leaching efficiency. Effects of temperature, time, LiCoO2: CPVC mass ratio and liquid-solid ratio on leaching efficiencies of Li and Co were investigated. Solid residues were characterized by XRD and SEM-EDS elemental mapping to predict chemical compounds remained after leaching. Results showed that more than 98.71 % of Li and 97.69 % of Co were effectively leached from LiCoO2 powder under the following conditions: temperature of 250 degrees C, reaction time of 60 min, and LiCoO2: CPVC mass ratio of 1:3. Results of this study suggest that recovery of Li and Co from spent LIBs using hydrothermal subcritical water is an efficient, environmental friendly and sustainable technology.