Preparation and electrochemical performance of Nb-doped LiFePO₄/C regenerated from spent Li-ion battery cathodes

This study explores a method for the large-scale recycling and reuse of spent LiFePO 4 from industry by synthesizing regenerated LiFePO 4 /C materials via a carbothermal reduction method using Nb-doped spent LiFePO 4 as precursors. Among these regenerated materials, the 3 wt% Nb-doped sample exhibits a first discharge capacity of 140.2 mA h/g at 1 C. At 0.1 C, 2 C, and 5 C, the first discharge capacities are 162.6, 125.4, and 75.3 mA h/g, respectively. These experimental results demonstrate the excellent electrochemical performance of the 3 wt% Nb-doped sample. The regeneration method employed in this study, which offers convenient operation, easy preparation, and low cost, proves to be a viable approach for recycling spent cathodes and reusing them.