Solar‐Driven Direct Lithium Extraction from Low‐Quality Brines

Owing to the crucial role in energy transformation for decarbonization, sustainable lithium (Li) supply has become growingly critical. Low-quality brines hold vast potential due to infinite reserves and diverse distribution but desire green and cost-effective extraction techniques against low Li concentrations and high magnesium-to-lithium ratios. Solar-driven direct lithium extraction (SDLE) systems combining conventional evaporation and DLE techniques can overcome the present challenges of Li extraction, promising to advance the exploitation of low-quality brines while simultaneously producing fresh water. However, the underlying construction principles and fundamental physical processes concerning SDLE systems are still uncovered comprehensively. This review first reveals the high-efficient and energy-effective Li extraction mechanisms from low-quality brines. Then, this work systematically presents construction and enhancement strategies, and the latest advancements and engineering applications of various SDLE systems, covering adsorption, membrane separation, crystallization separation, and electrochemical extraction. Furthermore, this work highlights the rational design of SDLE devices for water-Li co-production. Finally, this work discusses the challenges and future prospects for realizing SDLE systems from lab discovery to scale-up field demonstration. This review aims to bridge the gap between fundamental science and practical engineering behind the SDLE, unlocking different insights for resource sustainability and low-grade brines mining.