Efficient separation and recovery of lithium through volatilization in the recycling process of spent lithium-ion batteries

Spent lithium-ion batteries (LIBs) comprise different kinds of valuable metals with recovery and reuse value. Aiming to address the difficulty of recycling lithium from spent LIBs through conventional pyrometallurgy, a new method of high-efficiency separation and recovery of lithium through volatilization is proposed. In this new method, spent LIBs as the raw material, copper slag as the only flux and CaCl2 as an additive are utilized to recover lithium from spent LIBs. Under the optimal conditions, the volatilization rate of Li was 96.87%. During the smelting process, lithium is volatilized into the gas phase in the form of LiCl, where lithium can be recycled from the dust. In light of the experimental results, the addition of CaCl2 contributes to the formation of LiCl. The kinetics study showed that the volatilization of LiCl was controlled by an interfacial chemical reaction, and the apparent activation energy was 42.57 kJ/mol. In addition, Li2CO3 could be obtained from lithium-containing dust using a precipitation process. This method achieves efficient separation of lithium during the reduction smelting process. The phase transformation and kinetics of the separation process were investigated, and reaction mechanism was revealed. Importantly, the novel process provides new ideas and perspectives for the separation of lithium from spent LIBs through a pyrometallurgical process.