Spatial Decoupling Strategy Enhanced Ionic Liquid-Confined Porous MXene for Breakthrough Osmotic Energy Conversion.

Abstract

The potential of reverse electrodialysis for harvesting osmotic energy is severely limited by ion concentration polarization (ICP), a phenomenon that restricts power output and confines the technology to the laboratory scale (< 0.4 µW). This challenge is overcome with an ionic liquid confined porous MXene (IPM) system that integrates strategies across two scales. At the microscopic level, sub-nanometer channels are engineered using porous MXene and confined ionic liquids to reduce mass transfer resistance and optimize ion transport. Concurrently, at the macroscopic level, a micropore array design spatially decouples the diffusion interfaces to effectively suppress the ICP effect. This dual-scale approach increases power density by 53.6% and achieves a maximum output power of 3.47 µW, which is nearly ten times higher than that of similar work. The work demonstrates a robust pathway for overcoming critical power limitations, advancing osmotic energy conversion toward industrial renewable energy applications.