DGIST Scientists Blend Two Technologies to Produce a High-Efficiency Waste-Heat Energy Harvester
A team of scientists from Korea's Daegu Gyeongbuk Institute of Science and Technology (DGIST) have developed a hybrid energy harvesting system, which they say dramatically outperforms existing thermoelectrochemical cell (TEC) systems — allowing Internet of Things (IoT) devices to run entirely from low-grade waste heat.
"Our hybrid cell demonstrates a remarkable thermal conversion efficiency (5.2%) and outperforms the current best n-type TECs," says Hochun Lee, DGIST professor and project lead, of the team's work. "In addition, the simple structure and fabrication process of our TCCs offer a practically feasible platform for thermal energy harvesting."
The novel energy harvesting system is known as a thermoelectrochemical-concentration cell, or TCC, and is designed to combine the operating principle of a TEC with that of concentration galvanic cells — offering the best of both worlds and offering a dramatic performance gain once the temperature of the hot side goes above 40°C (104°F).
"IoT-connected societies will require economic and autonomous power sources for their IoT devices and sensors," Lee claims, "and we believe [TCCs] will be the ideal candidate to meet their need."
There's work still to be done, however: While the prototype devices built by the team offer high efficiencies, their absolute output is below that required by a useful IoT device — something Lee and colleagues hope to address by chaining multiple TCCs together in order to boost the output.
The team's work has been published in the Chemical Engineering Journal under closed-access terms.