Ionic Liquid-Armored MXene Membranes Enabling High-Performance Moisture-Driven Power Generation

Abstract

High-temperature moisture is commonly encountered in both natural and industrial processes, presenting significant opportunities for clean electricity generation. However, due to insufficient selective ion transport, traditional moisture-driven power generators (MPGs) face challenges in achieving high performance at elevated temperatures. To address this issue, we develop a membrane by confining ionic liquids within MXene nanosheets, resulting in an MPG that delivers a remarkable electrical current of 4.49 mA and a power density of 239.00 µW cm² at 100 °C, comparable to traditional hydropower stations. Molecular dynamics simulations and in-situ experimental characterization suggest that the highly hydrophilic surface of MXene facilitates the formation of an interfacial water layer and a stable hydrated anion state within the nanochannels at high temperatures. Consequently, the rapid diffusion of water at elevated temperatures significantly enhances the transport of anions while minimally affecting cation diffusion. This selective anion transport capability contributes to the MPG’s excellent moisture-driven power performance at high temperatures. Leveraging this enhanced power output, we further integrate the MPG device with a geothermal power generation system, demonstrating continuous power generation and efficient utilization of high-temperature geothermal steam.