High-performance phosphate cathode from revitalizing spent battery slag via Joule heating

Abstract

Spent lithium batteries (S-LIBs) are crucial for decoupling energy-metal demands from natural mineral extraction, with hydrometallurgy being the main lithium recovery method. However, spent slag management remains unexplored. We present a rapid (>99%) metal recovery technique using Joule-heating-induced high-temperature shock (HTS), converting spent LiMn₂O₄ and ferrophosphorus slag into LiMnFePO₄ in 1 s, defying traditional cathode synthesis. This achieves unprecedented material conversion efficiency, with exceptional energy density (579 Wh kg⁻¹) and cycling stability (87% capacity retention after 1,000 cycles). Compared with direct recycling or hydrometallurgy, multi-waste recycling reduces greenhouse gas emissions and energy consumption. A continuous industrial-grade HTS platform integrates smart manufacturing, accelerating LIB regeneration and production. This work establishes an efficient framework for sustainable closed-loop LIB recycling systems.