Production of battery grade power materials from spent lithium iron phosphate (LiFePO4) batteries

Abstract

Lithium iron phosphate (LiFePO₄) batteries have gained popularity due to their high safety and low cost. Effective recycling processes are needed to sustain indigenous material and economic benefit. In other hand, power materials are imported for the manufacturing of batteries, which compells for the development of process for recovery of the valuable metals (Fe, P, Li, Cu, and Al) from spent LFP batteries. Leaching was carried out at optimized condition using 3 % H₂SO₄ and 5 % H₂O₂ maintaining 100 g/L pulp density at 60 °C. 99.99 % Fe, Li, P, Al, and Cu were recovered within 60 min of mixing time. Leaching kinetics of Li followed “Chemical reaction control dense constant size cylindrical particles” model 1−(1−X)^1/2 = k_ct, while Fe, P, Al, and Cu adhered to a “Chemical reaction control dense constant size or shrinking spheres” model 1−(1−X)^1/3 = k_ct. Cementation was carried out using scrap iron to recover Cu at room temperature within 40 min. Fe and P were recovered as FePO₄ by precipitation. 99.99 % Al was precipitated using NaOH at pH 7.5, whereas 99.9 % Li was precipitated as Li₂CO₃ and Li₃PO₄ at pH 12 and 90 °C using Na₂CO₃ and Na₃PO₄.12H₂O, respectively. This process is viable for recycling LFP batteries ensuring resource recovery and environmental sustainability.