Improving Thermo-Electrochemical Cells Using Carbon Nanotubes

Thermo-electrochemical cells (TECs) allow us to recover the heat wasted from many sources directly, although the efficiency of the process is currently low. TECs are electrochemical devices that produce a steady electric voltage and current under an applied temperature difference between the electrodes. In order to improve the efficiency of TECs, it’s important to search for electrolytes with high electrical conductivities and low thermal conductivities. To this goal, we used impedance spectroscopy to study the effect of carbon nanotubes in ionic liquids used in TECs. Our research indicates that the addition of carbon nanotubes can result in a 3- to 5-fold increase of the mixture’s electrical conductivity. We further tested the power of coin sized-TECs using these novel mixtures. The results show that the addition of 0.06 wt% of carbon nanotubes to imidazolium-based ionic liquids with a modified cobalt redox couple improves the electrical power up to 80%, while there is no detectable change in the thermal conductivity of the mixture at this concentration of carbon nanotubes.