The influence of chlorination additives on metal separation during the pyrometallurgical recovery of spent lithium-ion batteries.

The difficulty of separating Li during pyrometallurgical smelting of spent lithium-ion batteries (LIBs) has limited the development of pyrometallurgical processes. Chlorination enables the conversion of Li from spent LIBs to the gas phase during the smelting process. In this paper, the effects of four solid chlorinating agents (KCl, NaCl, CaCl2 and MgCl2) on Li volatilization and metal (Co, Cu, Ni and Fe) recovery were investigated. The four solid chlorinating agents were systematically compared in terms of the direct chlorination capacities, indirect chlorination capacities, alloy physical losses and chemical losses in the slag. CaCl2 was better suited for use as a solid chlorinating agent to promote Li volatilization due to its excellent results in these indexes. The temperature required for the release of HCl from MgCl2, facilitated by CO2 and SiO2, was lower than 500 °C. The prematurely released HCl failed to participate in the chlorination reaction. This resulted in approximately 12 % less Li volatilization when MgCl2 was used as a chlorinating agent compared to when CaCl2 was used. In addition, the use of KCl as a chlorinating agent decreased the chemical dissolution loss of alloys in the slag. The performance of NaCl was mediocre. Finally, based on evaluations of the four indexes, recommendations for the selection and optimization of solid chlorinating agents were provided.

Applicability of the reduction smelting recycling process to different types of spent lithium-ion batteries cathode materials.

The high-temperature smelting process based on pyrometallurgy is influential in the field of recycling spent lithium-ion batteries (LIBs) on an industrial scale. However, there are a variety of cathode materials for spent LIBs. The applicability of the high-temperature smelting process to different kinds of cathode materials has not been reported. In this work, the applicability of the reduction smelting process to four different cathode materials is studied. The phase transition, distribution and existence of target elements and the characteristics of the smelting products when different cathode materials are used as raw materials are systematically discussed. The results show that the reduction smelting process can recover the four different cathode materials (LiCoO2, LiFePO4, LiMn2O4, LiNi0.8Co0.1Mn0.1O2) of spent LIBs. The reduction smelting process is also suitable for complex feedstocks containing the four cathode materials. The target elements Co, Cu, Ni, Fe and P are transferred to the alloy. The target elements Li and Mn volatilize into the gas phase. In addition, the future application of the reduction smelting process on an industrial scale is discussed and proposed. This study reveals the excellent applicability of the reduction smelting process to different LIB cathode materials and provides support for the development of a high-temperature smelting process based on pyrometallurgy.

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.