Thermogalvanic Waste Heat Recovery System in Automobiles

Waste heat recovery remains an inviting subject for research. Solid-state thermoelectric devices have been widely investigated, but their practical application remains challenging due to cost and inability to fabricate them in geometries that are easily compatible with heat sources. An alternative to such devices is thermogalvanic cells. Temperature difference between hot and cold electrodes creates a potential difference. Once they connect to a load, electric current and power are delivered, thus converting heat into electricity. Recent work in our laboratory has showed that an annular copper-copper sulfate thermogalvanic cell system, which was affixed conformingly onto a hot pipe to simulate car’s exhaust pipe, produced electricity in the order of tens of milliwatt per square meter. Therefore, the current study is essentially the continuation of that proof-of-concept work. We redesign and build new cells with increased electrodes’ surface area to generate more power. We also incorporate a flowing cell design to capture more waste heat from a car’s radiator. This study is a largely experimental approach to improve the power generation of the system, with the goal being to make possible future practical energy conversion devices for automotive industries.