Aromatic Ketone-Mediated Two-Electron Lithiation for Rapid and Room-Temperature Regeneration of Spent LiFePO ₄ Cathodes

Abstract

Addressing the growing demand for sustainable lithium-ion battery (LIBs) recycling, we present a novel aromatic ketone (AK)-mediated chemical lithiation reaction for the rapid and spontaneous regeneration of degraded lithium iron phosphate (D-LFP) cathodes within just 5 min at room temperature. Utilizing benzophenone (Bzp) as a representative low-toxicity and cost-efficient AK reagent, we demonstrate a unique two-electron transfer mechanism. This key innovation halves the required reagent stoichiometry compared to conventional single-electron systems, significantly enhancing both economic viability and environmental sustainability. The regenerated cathodes exhibit restored electrochemical performance, comparable to commercial materials in capacity retention and cycling stability. Crucially, the entire process operates at room temperature, and the reagent solution (Bzp/THF) can be efficiently recycled, achieving near-complete atomic economy and minimizing waste. This work establishes a rapid, cost-effective, and green closed-loop regeneration route with significant potential for advancing sustainable battery recycling technologies.