Decoupled Ionic and Electronic Pathways for Enhanced Osmotic Energy Harvesting

Abstract

Methods of reducing nanofluids’ internal resistance by mixing conductive nanomaterials will negatively affect the nanochannel structures and ion transmissions. Herein, a layered-structured nanofluidic membrane that achieves ion transport in the internal cellulose nanochannels and realizes electron transport in the external polyaniline network is developed. Results show that the ionic conductivity and resistivity of the layered membrane at low salt concentrations are 1.57 times higher and 0.99 times lower than those of the blend membrane, demonstrating the positive contribution of decoupled ionic and electronic pathways. Furthermore, the layered membrane attained an enhanced output power density of 11.7 W m-2 and maintained an output performance of up to 10.9 W m-2 after 16 days of operation under the neutral 50-fold salinity concentration gradient, which is higher than that of the commercial system (5.0 W m-2). Overall, this research expands the materials for osmotic energy-harvesting systems based on the design of ion and electron decoupling paths in biomass materials.