Direct Regeneration of Spent LiFePO ₄ Cathodes by Liquid‐Phase‐Mediated Reconstruction

Directregeneration of spent LiFePO ₄ (S‐LFP) cathodes is imperative for sustainable battery recycling, yet it remains severely hindered by inherent structural degradation, specifically lithium depletion and irreversible Fe ³⁺ formation. Herein, we propose a facile, one‐step liquid‐phase mediated method to directly repair S‐LFP. By constructing a liquid‐phase‐mediated system comprising Fe/Li‐based salts and sucrose, this method kinetically accelerates ionic diffusion and ensures homogeneous elemental distribution at a low temperature (300 °C). Concurrently, the synergistic effect of the liquid‐phase‐mediated state and a reducing atmosphere facilitates the complete structural restoration from Fe ³⁺ to electrochemically active Fe ²⁺ . Consequently, the regenerated LFP (R‐LFP) demonstrates exceptional electrochemical reversibility, delivering a superior initial capacity of 158.5 mAhg ⁻¹ at 0.1 C. Notably, practical full‐cell evaluations exhibit robust long‐term cycling stability, retaining 80.0% capacity over 1500 cycles at a high rate of 2 C. Techno‐economic analysis confirms that this low‐cost, liquid‐phase‐mediated regeneration protocol outperforms conventional hydro/pyrometallurgical routes, establishing a viable, scalable closed‐loop LFP recycling pathway.