asymmetric-thermoelectrochemical-cell-for-harvesting-low-grade-heat

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

Low-grade heat is abundantly available in the environment as waste heat. The efficient conversion of low-grade heat into electricity is very difficult. We ...

University of Hong Kong

Efficient low-grade heat recovery can help to reduce greenhouse gas emission as over 70% of primary energy input is wasted as heat, but current technologies to fulfill the heat-to-electricity conversion are still far from optimum. Here we report a direct thermal charging cell, using asymmetric electrodes of a graphene oxide/platinum nanoparticles cathode and a polyaniline anode in Fe/Fe redox electrolyte via isothermal heating operation. When heated, the cell generates voltage via a temperature-induced pseudocapacitive effect of graphene oxide and a thermogalvanic effect of Fe/Fe, and then discharges continuously by oxidizing polyaniline and reducing Fe under isothermal heating till Fe depletion. The cell can be self-regenerated when cooled down. Direct thermal charging cells attain a temperature coefficient of 5.0 mV K and heat-to-electricity conversion efficiency of 2.8% at 70 °C (21.4% of Carnot efficiency) and 3.52% at 90 °C (19.7% of Carnot efficiency), outperforming other thermoelectrochemical and thermoelectric systems.

Kaiyu Mu

Electrochemical Nanoengineering Group,
Department of Mechanical Engineering,
Electrochemical Nanoengineering Group, Department of Mechanical Engineering

University of Hong Kong

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

Kaiyu Mu

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Electrochemical Nanoengineering Group,Department of Mechanical Engineering,Electrochemical Nanoengineering Group, Department of Mechanical Engineering

University of Hong Kong

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

Electrochemical Nanoengineering Group,
Department of Mechanical Engineering,
Electrochemical Nanoengineering Group, Department of Mechanical Engineering