New publication in Advanced Functional Materials
Sol-gel phase transition in ionic thermoelectrical (i-TE) materials induced large rapid change in viscosity and ionic transport process thus it was expected to give a drastic variation in thermoelectric properties, crucial in low-grade waste heat harvesting for Internet of thing (IoT) and wearable electronic applications. Prof. Xiaoming TAO’s research team prepared and examined four types of ionic thermoelectric materials featured with non-phase-transition, thermal sol-to-gel phase-transition, thermal gel-to-sol phase-transition and UV-induced sol-to-gel phase-transition, which was recently published in Advanced Functional Materials. For the first time, a large rise of the thermopower was observed by 6.5 times during the sol-gel transition of poloxamer/LiCl system, an even greater ionic figure of merit by around 23 times. The phenomenon was found to be universal as the large variation in thermopower was confirmed in the other thermal gel-sol transitional and UV induced transitional materials. In addition, the mechanism and proposed a model was further revealed that dealt with the pre-, post- and during- phase-transition processes. Finally, six factors were probed influencing the huge variation of the thermopower during the phase-transition and shed light on the possible gigantic changes of thermopower during the phase transition. A possible route to design and control the desired TE performances of materials was uncovered, which can lead to a new sight in tunable i-TE devices for low-heat energy harvesting applications.
