Ultra-fast mechanochemistry reaction process: An environmentally friendly instant recycling method for spent LiFePO4 batteries

Abstract

As LiFePO4 (LFP) gradually becomes the leader in the energy storage and power battery field, achieving a green and efficient industrialized recovery of Li from the stable lattice structure of LFP has become a significant requirement for driving resource and environmental sustainability. Here, a non-acid wet ultra-fast mechanochemistry reaction (UMR) instantaneous metallurgy technology is proposed, water leaching has obvious green and sustainable advantages. Including the wet mechanochemical reaction of C10H14N2Na2O8 assisted H2O2 and water leaching to deconstruct the orthorhombic olivine structure, and an innovative, detailed explanation of the mechanism of this technology is presented from the perspective of the synergy between mechanics and chemistry. The results indicate that under optimal conditions, stress energy accumulation and single-factor conditions can instantly achieve the activation process of efficiently deintercalating Li and enriching Fe in a single step within 4 mins, while still maintaining the olivine structure. Through the coupling of UMR with chelation reactions, the fastest selective recovery of 99.17 % of Li is achieved. Following filtration and precipitation, Fe and Li are ultimately recovered in the form of FePO4 and Li2CO3 precursors, respectively. Grey correlation analysis, grain flows numerical simulation, and the mechanism of chemical reactions indicate that rotation speed is the most critical factor affecting Li recovery, leading to the desorption of Fe(III) and Li+ mainly caused by the wear to the lattice structure by normal cumulative force, energy accumulation dissipation-induced advanced oxidation reactions, and chelation reactions. The non-acid USMR reported in this study offers a sustainable new pathway for the rapid extraction of Li from spent LFP for industrial purposes.