Power Generation by Thermal Evaporation Based on a Button Supercapacitor.

Abstract

Thermal evaporation generators exhibit remarkable output performance, sustainability, and economy and, as a result, have attracted considerable interest as a prospective energy-converting technology for harvesting renewable energy. Here, we investigate power generation induced by water evaporation within a button supercapacitor with a simple sandwich structure. For conventional water evaporation devices, the thermodiffusion direction of hydrated ions driven by the Soret effect is opposite to the migration direction of hydrated ions driven by the streaming potential effect during thermal evaporation, which could reduce the output performance of the device. By tuning the thermodiffusion direction to be consistent with the thermal evaporation direction, our button supercapacitor achieves enhanced output performance as high as 674.4 mV, 70.7 mA, and 4.68 mW cm-2 due to the synergistic mechanism of the streaming potential effect and the Soret effect. Moreover, the system could effectively achieve in situ energy generation and storage owing to the device's ability to act as a supercapacitor. Our findings supply a feasible strategy for the synergistic integration of waste energy sources (low-grade waste heat, etc.) to generate electricity.