Regeneration of LiFePO4 from spent materials: control and influence of Al impurity

Owing to the rapid increase of lithium iron phosphate (LiFePO4) batteries, recycling and regeneration of LiFePO4 enjoys significances for sustainable development and environmental protection. In this study, an effective regeneration method for spent LiFePO4 materials and the influence of Al impurity on the electrochemical performance of regenerated LiFePO4 were studied. Firstly, 99.26% Fe, 99.52% P, 99.58% Li, 59.36% Al and 20.24% Cu in spent LiFePO4 material were leached with 150 g•L‐1 H2SO4. Subsequently, Al removal and control were achieved by simply adjusting the pH value, and FePO4•2H2O precursors with different Al contents were prepared. Specially, the LiFePO4 regenerated by FePO4•2H2O precursor containing 0.096% Al exhibits excellent electrochemical performance with discharge capacity of 145 mAh•g‐1, 140.5 mAh•g‐1 and 130.9 mAh•g‐1 at the current density of 1C, 2C and 5C, respectively.