Fast Electron Transfers of Non-Noble-Metal Tungsten Carbide Electrodes for Aqueous Thermo-Electrochemical Cells in Neutral Media

Thermo-electrochemical cells (TECs) are attracting significant attention because of their ability to harvest waste heat energy. They are considered suitable replacements for thermoelectric devices because of their flexibility, simple structure, and high stability. However, the extensive application of TECs is limited by the high cost of their constituent materials, such as nanostructured carbon or Pt electrodes. In this study, a highly active tungsten carbide (WCx) electrode was employed as a substitute for Pt and nanostructured carbon-based electrodes in a TEC. This non-noble-metal electrode delivered an outstanding power output of 1.16 W m–2 and dramatically lowered the cost of the TEC system. Moreover, the maximum power output of the WCx-based TEC was maintained for over 10 days. This study highlights the significant application potential of WCx as a non-noble-metal-based electrode material for harvesting waste heat energy, attributed to its activity, economic feasibility, and stability.