Closing the Loop on Lithium-Ion Battery Cathodes: A Green Electrometallurgical Recycling Approach

The burgeoning use of lithium-ion batteries (LIBs) creates a growing challenge: spent battery management. Traditional hydrometallurgical recycling with coprecipitation generates massive Na 2 SO 4 wastewater, posing a significant environmental burden. This work presents a novel, closed-loop recycling method for LIB cathode materials that merges electrolysis and hydrometallurgy. Using Na 2 SO 4 electrolysis, we produced high-purity sulfuric acid and sodium hydroxide solutions, which served as the key reagents for leaching and resynthesizing waste cathodes. Optimized leaching conditions ensure near-complete recovery of valuable metals. Li 2 CO 3 and a precursor (Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 ) are subsequently precipitated and regenerated into a new LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode material, which demonstrates excellent electrochemical performance. The spent Na 2 SO 4 solution undergoes a simple treatment before re-electrolysis, achieving a closed-loop system with minimal waste generation and reduced reliance on external reagents. Moreover, the acid-leaching carbon residue is repurposed as a bifunctional carbon-based catalyst for hydrogen peroxide production. This innovative approach offers both economic and environmental benefits, paving the way for sustainable LIBs recycling and a circular economy for battery materials.