Unique ion rectification in hypersaline environment: A high-performance and sustainable power generator system

摘要: The development of membrane science plays a fundamental role in harvesting osmotic power, which is considered future clean and renewable energy source. However, the existing designs cannot handle low conversion efficiency power density. Theory has predicted that Janus with ionic diode–type current would be most efficient material. Therefore, rectified transportation hypersaline environment (the salt concentration at least 0.5 M sea) highly desired, but it still remains challenge. Here, we demonstrate versatile strategy for creating scale-up three-dimensional (3D) porous membrane–based generator system. membranes tunable surface charge density porosity were obtained by compounding two kinds ionomers. Under electric fields or chemical gradients, rectification properties anion selectivities environment. Experiments theoretical calculation abundant narrow pore size distribution benefit this unique transport behavior high solution. Thus, output membrane-based reaches 2.66 W/m2 (mixing seawater river water) up to 5.10 500-fold salinity gradient (i.e., flowing lake into water). Furthermore, generator, built connecting series membranes, could calculator 120 hours without obvious decline, proving excellent physical stabilities. believe work advances understanding fluid materials design as paradigm high-performance generator.