Water Evaporation‐Enhanced Thermogalvanic Cell for Waste Steam Utilizing

Abstract Huge amounts of thermal energy are wasted in the form of steam in the industrial production process. Thermogalvanic cell shows great potential in harnessing this low‐grade thermal energy, and one challenge is to increase the output power. In this study, a water evaporation‐enhanced thermogalvanic cell (WE‐TGC) is developed that exposes the electrolyte to ambient air, utilizing spontaneous water evaporation to effectively regulate the electrolyte concentration distribution and cold‐end temperature. When waste steam of 323 K is used as the heat source, the thermopower can be enhanced from traditional value (1.39 mV K −1 ) to 3.25 mV K −1 because of the additional electrolyte concentration gradient. The cold‐end temperature of the WE‐TGC can be even lower than the ambient temperature, resulting in an output power of 213.07 mW m −2 , which is 1222% higher than that of the conventional thermogalvanic cell. This work offers a fresh perspective to enhance the performance of thermogalvanic cells and optimize the utilization of waste steam.