Powerful Thermogalvanic Cells Based on Reversible Hydrogen Electrode and Gas-Containing Electrolytes
2019
Thermogalvanic cells (TGCs) directly convert waste heat to electricity, but the efficiency has been limited largely by the contradiction between thermal resistance and electrical conductance. Here we report a new design of TGC that can disentangle such a dilemma and thus accelerate the thermoelectric conversion. The key is to replace the traditional liquid-based redox reaction and single-phase mass transport with an internal gas/liquid two-phase system. We choose the rapid H2/H+ redox reaction that generates H2 gas at the hot electrode while consuming it at the cool electrode. Between the electrodes is a 3D-printed thin separator comprising straightly aligned H2/electrolyte microchannels for fast H2/H+ transport. Besides gaining additional entropy from the water-vaporizing effect, such a gas-containing electrolyte layer, albeit only 0.36 mm in thickness, has diminished the heat convection between electrodes. The power density of this TGC reaches 4 W/m2 at a temperature difference of 30 K.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
29
References
15
Citations
NaN
KQI