Waste heat is abundantly available in the environment, conversion of primary energy and even in human body. Existing technology to convert low-grade heat to electricity is expensive, complicated or low in efficiency. The team led by Ir Prof Feng Shien Ping invented the Direct Thermal Charging Cell, which may be the key to unlock the potential of heat-to-electricity conversion.
This new electrochemical system uses asymmetric electrodes of graphene oxide (GO)/Pt nanoparticles cathode and polyaniline anode in aqueous Fe2+/Fe3+ redox electrolyte for the efficient conversion of low-grade heat to electricity, which is self-regenerated. The cell has a heat-to-electricity efficiency of 3.5%, surpassing the 1% of existing technology in low grade heat regime. Each basic unit sized only 1.5 sq.cm and thickness 1 to 1.5 mm and it is low cost, bendable and technically simple, bringing a fundamental change to the heat-to-electricity conversion.
Ir Prof Feng believes low-grade heat is a source of renewable energy that being overlooked. It will be a promising opportunity to hike up energy efficiency and cut carbon emission, which will bring tangible economic and environmental benefits to the society.
Ir Prof Feng is a Professor of Advanced Design and Systems Engineering at City University of Hong Kong. Before entering academia, he was working at Taiwan Semiconductor Manufacturing Company and Tripod Technology Corporation. By establishing startup company and collaborating with industries, the invention is moving from academic research toward real applications.