Fe(III)/Fe(II) Redox-Based Lithium Extraction/Recovery from Liquid- and Solid-Phase Lithium Resources

Lithium plays a vital role in electrochemical energy conversion and storage that greatly promotes global sustainable development. This stimulates lithium consumption but creates an imbalance between the supply and demand of lithium. Here, we demonstrate an Fe(III)/Fe(II) redox-based electrochemical strategy to simultaneously extract lithium from both liquid- and solid-phase resources and power supply, in which lithium extraction from solid-phase resources is driven by a chemical redox reaction, not consuming the energy. Taking Li3[Fe(CN)6]/Li4[Fe(CN)6] and Zn2+/Zn redox couples as the proof-of-concept model, the constructed system with 15 mL of 0.5 mol L–1 electrolyte exhibits an extraction capacity of 91.9 mg, an energy consumption of 0.6 kWh kgLi–1, and electricity output of 234.6 mWh (15.6 Wh L–1) in a single discharge/charge cycle. Further, the performance can be linearly improved by increasing the electrolyte concentration, showing tremendous potential for real application. This work presents a green, low-carbon, and high-efficiency way to alleviate the imbalance between the supply and demand of lithium.