Bio‐Inspired Site‐Specific Atomic Repair for Energy‐Efficient Regeneration of Spent LiFePO ₄ Batteries

Abstract

ABSTRACT Solid‐state sintering regeneration offers a promising strategy for repairing spent lithium iron phosphate (LFP) cathodes, yet conventional homogeneous‐mixing (HM) sintering approaches neglect the intrinsic heterogeneity of FePO 4 within LFP particles. This induces additional long‐range Li +  solid‐state migration from Li‐rich to Li‐deficient domains during regeneration, creating substantial solid‐state diffusion barriers that necessitate extended high‐temperature sintering duration while triggering local over‐lithiation, ultimately degrading regeneration performance. Inspired by specific antigen‐antibody‐phagocyte interactions, we propose a novel mechanistic concept of site‐specific atomic repair (SAR) for energy‐efficient LFP regeneration. Through targeted‐adsorption‐enhanced evaporation‐nucleation processes, lithium sources and reductants are selectively anchored onto heterogeneous FePO 4 domains for localized repair, which shortens Li + solid‐state diffusion pathways, lowers migration barrier, and reduces FePO 4 → LiFePO 4 transition temperature from 300–400°C to 100–200°C. Consequently, the SAR‐regenerated LFP cathodes deliver enhanced performance while requiring only half of the high‐temperature sintering duration of conventional HM approaches, thereby achieving ∼20%–30% reduction in energy consumption & CO 2 emissions with a markedly improved profit by ∼40%. With additional heteroatom doping, SAR demonstrates exceptional rate performance (73.0 mAh g −1 at 15 C) and long‐term stability (90.0% after 600 cycles), ranking among the best reported to date, demonstrating cost‐effective mechanistic advances for industrial‐scale LFP recycling.