High efficiency reduction leaching of iron phosphate residue from the recycling of spent LiFePO4 battery

The effective reuse of iron phosphate residue (IPR) is the key issue in the recycling of spent LiFePO4 batteries. The reduction leaching of IPR in H2SO4 solution by adding iron powder as reducing agent was investigated, and compared with direct leaching. The results show that the leaching rate of IPR reached 97% under the optimum reduction leaching conditions. Kinetic studies show that the activation energy for reduction leaching is 12.71 kJ/mol, while that of direct leaching is 21.57 kJ/mol. The reduction leaching time is reduced by half and the acid consumption is reduced by 30% compared to direct leaching with the same leaching rate. This work provides a scientific guidance to the treatment of iron phosphate residue from the recycling of spent LiFePO4 batteries