Selective recovery of lithium from spent lithium iron phosphate batteries

Abstract

The recovery of lithium from spent lithium iron phosphate (LiFePO4) batteries is of great significance to prevent resource depletion and environmental pollution. In this study, through active ingredient separation, selective leaching and stepwise chemical precipitation develop a new method for the selective recovery of lithium from spent LiFePO4 batteries by using sodium persulphate (Na2S2O8) to oxidize LiFePO4 to FePO4. The impact of various variables on the efficiency of lithium leaching was investigated. Moreover, a combination of thermodynamic analysis and characterization techniques such as X-ray diffraction and X-ray photoelectron spectroscopy was employed to elucidate the leaching mechanism. It was found that 98.65% of lithium could be selectively leached in just 35 minutes at 60°C with only 0.2 times excess of Na2S2O8. This high leaching efficiency can be attributed to the stability and lack of structural damage during the oxidation leaching process. The proposed process is economically viable and environmentally friendly, thus showing great potential for the large-scale recycling of spent LiFePO4 batteries.