High power density electrochemical thermocells for inexpensively harvesting low-grade thermal energy

Continuously operating thermo-electrochemical cells (thermocells) are of interest for harvesting low-grade waste thermal energy because of their potentially low cost compared with conventional thermoelectrics. Pt-free thermocells devised here provide an output power of 12 W m−2 for an interelectrode temperature difference (ΔT) of 81 °C, which is sixfold higher power than previously reported for planar thermocells operating at ambient pressure.