Regeneration of LiFePO from Spent Materials: Control and Influence of Al Impurity.

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