Coupling flexible stripping with efficient impurity removal for high-quality regeneration of spent LiFePO4 materials.

Lithium iron phosphate (LiFePO4) batteries are widely used in electric vehicles and energy storage systems due to their superior safety and cycling stability. However, their limited lifespan results in substantial spent battery accumulation. Current recycling methods face challenges including high costs, inefficient cathode detachment, and inadequate removal of metallic impurities. This study proposes a flexible stripping combined with efficient decontamination to achieve regeneration of spent LiFePO4. The physical stripping method achieves >99 % cathode detachment efficiency without structural degradation. Subsequent FeCl3-assisted decontamination removes 100 % Cu and >82 % Al impurities while retaining organic components. Residual organics and Al compounds act synergistically as carbon sources and dopants, enhancing electrochemical performance. Regenerated cathodes using Li2CO3 and glucose deliver an initial capacity of 150.3 mAh/g at 0.1 C and 96.43 % capacity retention after 100 cycles at 1 C, matching commercial material performance. This strategy offers an efficient, low-cost pathway for closed-loop LiFePO4 recycling with industrial scalability.