Photovoltaic-driven dual-oxidation seawater electrolyzer for sustainable lithium recovery

The insatiable demand for lithium in portable energy storage necessitates a sustainable and low-carbon approach to its recovery. Conventional hydrometallurgical and pyrometallurgical methods heavily involve hazardous chemicals and significant CO₂ emissions. Herein, by integrating electrode oxidation with electrolyte oxidation, we establish a photovoltaic-driven "dual-oxidation" seawater electrolyzer system for low-carbon footprint and high lithium recovery. A 98.96% lithium leaching rate with 99.60% product purity was demonstrated for lithium recovery from spent LiFePO₄ cathode materials. In-depth mechanism studies reveal that the electric field-driven electrode oxidation and in situ generated oxidative electrolyte synergetically contributes to lithium ions leaching via a structural framework elements oxidation and particle corrosion splitting synergy. This dual-oxidation mechanism facilitates rapid and efficient lithium extraction with broad universality, offering significant economic and environmental benefits. Our work showcases a promising strategy for integrating dual oxidation within a photovoltaic-driven seawater electrolyzer, paving the way for low-carbon lithium recovery from diverse solid wastes and minerals within a sustainable circular economy.