EurekAlert February 12, 2020
A thermocell can convert environmental thermal energy to electric energy via thermal charging effect. However, the output voltage is low and depends on temperature. Researchers in Japan developed a thermocell containing a material that exhibited a temperature-induced phase transition of its crystal structure. Just above room temperature, the atoms in this solid material rearranged to form a different crystal structure. This phase transition resulted in an increase in output voltage from zero to around 120 mV, representing a considerable performance improvement over that of existing thermocells. They were able to finely tune the phase transition temperature of the material so that it lay just above room temperature. When a thermocell containing this material was heated above this temperature, the phase transition of the material was induced, which led to a substantial rise of the output voltage from zero at low temperature to around 120 mV at 50 °C…read more. Open Access TECHNICAL ARTICLE
Schematic structure of NaxCo[Fe(CN)6]y (Co-PBA) in the (a) low-spin (LS) and (b) high-spin (HS) phases. Credit: Nature Scientific Reports volume 10, Article number: 1813 (2020)