Carbothermal Reduction of Spent Mobile Phones Batteries for the Recovery of Lithium, Cobalt, and Manganese Values

Abstract

Lithium-ion batteries have a limited lifespan and ever-growing demand and the presence of critical metals such as lithium and cobalt make their recycling inevitable. In this study, discarded mixed mobile batteries were discharged, dismantled, and separated into cathode and anode sheets, followed by attritor crushing. The cathode material comprises LiCoO2 and LiMn2O4, while graphite is present in the anode material. The cathode material was indigenously reduced with purified graphite in a muffle furnace at different times and dosages. A Taguchi statistical design is employed for the optimization of reduction parameters and the obtained magnetic fraction contains cobalt and manganese oxide, whereas graphite and lithium carbonate were found in a nonmagnetic fraction and dried solution. The composition, saturation magnetization and product phases obtained in optimum conditions (900°C, 7.5% graphite, 45 min and 800°C, 7.5% graphite, 45 min) are: Co: ~ 80 to 84%; Mn: 6–10%; and saturation magnetization: 105–114 emu/g with Co, CoO and MnO phases, respectively.