Nickel and cobalt recycling from lithium-ion batteries by electrochemical processes

The presence of LiCoO2 and LiCoxNi(1 − x)O2 in the cathodic material of Li-ion and Li-polymer batteries has stimulated the recovery of Co and Ni by hydrometallurgical processes. In particular, the two metals were separated by SX method and then recovered by electrochemical (galvanostatic and potentiostatic) processes. The metallic Ni has been electrowon at 250 A/m2, pH 3–3.2 and 50 °C, with 87% current efficiency and 2.96 kWh/kg specific energy consumption. Potentiostatic electrolysis produces a very poor Ni powder in about 1 h with current efficiency changing from 70% to 45% depending on Ni concentration in the electrolyte. Current efficiency of 96% and specific energy consumption of 2.8 kWh/kg were obtained for Co at 250 A/m2, pH 4–4.2 and 50 °C, by using a solution containing manganese and (NH4)2SO4. The Co powder, produced in potentiostatic conditions (−0.9 V vs. SCE, pH 4, room temperature) appears particularly suitable for Co recycling as cobaltite in new batteries.