The demand for lithium extraction from salt-lake brines is increasing to address the lithium supply shortage. Nanofiltration (NF) separation technology has shown great potential for lithium extraction, but it often requires diluting the brine with large amounts of freshwater and only yields Li⁺-enriched solutions. Inspired by the selective ion uptake and salt secretion processes in mangroves, researchers have developed a synergistic design of an ion separation membrane and a solar-driven evaporator to directly extract lithium from salt-lake brines. The ion separation membrane-based solar evaporator consists of three functional layers: a photothermal layer for water evaporation, a hydrophilic porous membrane for generating capillary pressure, and an ultrathin ion separation membrane for allowing Li⁺ to pass through while blocking other multivalent ions. This system effectively reduces the Mg²⁺/Li⁺ ratio by 66 times (from 19.8 to 0.3) when treating artificial salt-lake brine with a high salt concentration of 348.4 g L⁻¹. The research combines ion separation with solar-driven evaporation to directly obtain LiCl powder, providing an efficient and sustainable approach for lithium extraction. The device can be scaled up easily and has shown great potential for practical lithium extraction, making it a promising method to secure the lithium supply for future energy uses.The demand for lithium extraction from salt-lake brines is increasing to address the lithium supply shortage. Nanofiltration (NF) separation technology has shown great potential for lithium extraction, but it often requires diluting the brine with large amounts of freshwater and only yields Li⁺-enriched solutions. Inspired by the selective ion uptake and salt secretion processes in mangroves, researchers have developed a synergistic design of an ion separation membrane and a solar-driven evaporator to directly extract lithium from salt-lake brines. The ion separation membrane-based solar evaporator consists of three functional layers: a photothermal layer for water evaporation, a hydrophilic porous membrane for generating capillary pressure, and an ultrathin ion separation membrane for allowing Li⁺ to pass through while blocking other multivalent ions. This system effectively reduces the Mg²⁺/Li⁺ ratio by 66 times (from 19.8 to 0.3) when treating artificial salt-lake brine with a high salt concentration of 348.4 g L⁻¹. The research combines ion separation with solar-driven evaporation to directly obtain LiCl powder, providing an efficient and sustainable approach for lithium extraction. The device can be scaled up easily and has shown great potential for practical lithium extraction, making it a promising method to secure the lithium supply for future energy uses.