A novel mechanical pre-treatment process for the recovery of valuable materials for portable Li-ion batteries

The increasing global demand of Li-ion batteries (LIBs) led to an increasing demand of raw materials that, just for Electric Vehicles (EV) market (25% of global market), in the next 15 years will be about 65-fold the current one for graphite, Nickel and Aluminum and 100 times for Lithium, Cobalt and Manganese (Bloomberg, 2017). According to this data and considering a battery lifetime between 300-500 discharge/charge cycles, in 2040 between 70 and 550 Mio kg of EV wasted LIBs (Natkunarajah et al., 2015) will have to be treated ensuring an efficient metals recovery, according also to the increasingly strict environmental regulation. Nowadays LIBs are treated by using pyrometallurgical processes for materials decomposition and/or evaporation at high temperature. These processes require a significant energy consumption, a proper monitoring to avoid environmental issues due to polymeric decomposition, and an additional chemical treatment for metals purification. In order to overcome these drawbacks, the present study proposes the optimization of a mechanical pre-treatment, combined with hydrometallurgical processes, to increase extraction efficiency, in a more energy and costs saving eco-friendly framework. This mechanical pre-treatment allows target materials concentration, i.e. the separation of the oxide layer on Aluminum foil (cathode electrode) containing Co, Ni, Mn, etc. The process was thoroughly investigated by experiments with the aim of optimizing approaches and working parameters; the efficiency has been validated according to grade and recovery rate evaluation. The study has been performed at "De- and Remanufacturing" Pilot Plant of STIIMA-CNR, in collaboration with the Italian batteries collecting scheme COBAT.