Comparative study of the dissolution of LCO in HCl medium with and without H2O2

Abstract

The dissolution of LiCoO2 (LCO) from spent lithium-ion batteries (LIBs) has been widely studied with organic and inorganic acids. Among these acids, HCl is the one that showed the best results when used at concentrations higher than 4 M. However, its higher cost compared with other acids is disadvantageous. Taking this into account, this work aims to perform a comparative study of the effect of different operational variables such as temperature, reaction time, leaching agent concentration (HCl) and reducing agent concentration (H2O2) on the dissolution efficiency of LCO for the systems HCl and HCl-H2O2 to determine the optimal parameters to achieve a maximum dissolution in minimum time at low temperatures and reagent concentrations. Increasing temperature, time and concentration of the reagents had a positive effect on the dissolution of LCO. When working with HCl 1.8 M, the highest dissolution for LCO, 91.0% was obtained at 348 K for 60 min. Furthermore, a slightly higher oxide dissolution (93.0%) was obtained in a reducing medium at the same temperature in half the time and with a concentration of HCl more than ten times lower. This will allow us to propose an alternative process to the existing ones with economic and ecological advantages.