Continuing technological development decreases the useful lifetime of electronic equipment, resulting in the generation of waste and the need for new and more efficient recycling processes. The objective of this work is to study the effectiveness of supercritical fluids for the leaching of cobalt contained in lithium-ion batteries (LIBs). For comparative purposes, leaching tests are performed with supercritical CO₂ and co-solvents, as well as under conventional conditions. In both cases, sulfuric acid and H₂O₂ are used as reagents. The solution obtained from the supercritical leaching is processed using electrowinning in order to recover the cobalt. The results show that at atmospheric pressure, cobalt leaching is favored by increasing the amount of H₂O₂ (from 0 to 8% v/v). The use of supercritical conditions enable extraction of more than 95 wt% of the cobalt, with reduction of the reaction time from 60 min (the time employed in leaching at atmospheric pressure) to 5 min, and a reduction in the concentration of H₂O₂ required from 8 to 4% (v/v). Electrowinning using a leach solution achieve a current efficiency of 96% and a deposit with cobalt concentration of 99.5 wt%.