Carbothermal regeneration of LiFePO₄/C cathode material by recycling the precursors from out-of-line LiFePO₄ cells

In this work, the LiFePO₄/C (LFP/C) cathode material was regenerated by carbothermal processing using Li₂CO₃, Li₃PO₄, and FePO₄ precursors recycled from out-of-line (substandard) LFP cells. The separated black mass was converted into the various metal precursors, Li₂CO₃, Li₃PO₄, and FePO₄. The LFP/C powders were then regenerated by the carbothermal reaction between the metal precursors in various molar ratios of lithium precursor to FePO₄ (1:1, 1.05:1, and 1.10:1) and sucrose as a carbon source. The LFP/C powders regenerated from Li₂CO₃ and FePO₄ precursors at a molar ratio of 1:1 exhibited long-term cycling performance, with 90% capacity retention after 2,000 charge/discharge cycles at a current density of 20C.