In the journal ACS Energy Letters, researchers report producing a semipermeable membrane that gathers osmotic energy from salt gradients and converts it to electricity.The new design had an output power density more than 2 times higher than industrial membranes in laboratory demonstrations.Advancements in Osmotic Energy TechnologyOsmotic energy can be produced anywhere salt gradients are found, however the readily available innovations to record this eco-friendly energy have room for improvement. Dongdong Ye, Xingzhen Qin, and colleagues created a semipermeable membrane from ecologically friendly materials that would in theory decrease internal resistance and take full advantage of output power.Innovative Membrane Design by ResearchersThe researchers RED membrane prototype included different (i.e., decoupled) channels for ion transport and electron transportation. In a water tank that simulated an estuary environment, their model achieved an output power density 2.34 times higher than an industrial RED membrane and kept performance throughout 16 days of non-stop operation, demonstrating its long-term, stable efficiency underwater.In a last test, the group created a salt battery range from 20 of their RED membranes and produced enough electricity to individually power a calculator, LED light, and stopwatch.Practical Applications and Future ProspectsYe, Qin, and their team members say their findings broaden the variety of eco-friendly products that might be used to make RED membranes and improve osmotic energy-harvesting performance, making these systems more feasible for real-world use.Reference: “Decoupled Ionic and Electronic Pathways for Enhanced Osmotic Energy Harvesting” 24 April 2024, ACS Energy Letters.DOI: 10.1021/ acsenergylett.4 c00320The authors acknowledge financing from the National Natural Science Foundation of China.