Bisulfate transport in hydrogels for self-healable and transparent thermoelectric harvesting films

Abstract

A wearable and transparent thermoelectric (TE) hydrogel based on bisulfate transport was demonstrated to record a negative ionic Seebeck coefficient of −25.0 mV K-1, ionic power factor of 9.94 mW...

Mesogenic polymer composites for temperature-programmable thermoelectric ionogels

“…1,2 Among the possible power sources for intelligent devices, ionic thermoelectrics (iTEs) composed of ionic polymers are emerging as competitive candidates in terms of a high thermovoltage generation compared to traditional organic thermoelectrics due to their potential as so wearable electronics and Seebeck voltages that are large enough to operate low-voltage driving electronics from a small thermal gradient between the environment and iTEs. [3][4][5][6][7][8][9][10][11] The thermoelectric performance of materials is dened using the thermoelectric gure of merit, ZT ¼ S 2 sT k , where S is the Seebeck coefficient, s is the carrier conductivity, T is the absolute temperature, and k is the thermal conductivity. 12 Generally, the electric thermoelectric performance of polymers depends on the power factor (PF ¼ S 2 s) due to their intrinsically low thermal conductivity.…”

“…13 Under a temperature gradient for ionic conductors, this effect can produce positive or negative thermovoltages according to the charge type of the major ionic species (cation or anion), respectively, which is an important characteristic in iTEs for practical applications such as iTE modules with series connection. 11 However, there have been few reports for iTE materials with negative ionic Seebeck coefficient (S i ), 11,[14][15][16][17][18][19][20] because of the difficulty in controlling anion transport and the low diffusivity of anions rather than cations due to the large anion size. Nonetheless, the PF for ionic polymers could be dramatically enhanced by taking advantage of a high S i value from ion channel control in the hydrogel matrix and easy carrier-ion tuning.…”

Advanced Bacterial Cellulose Ionic Conductors with Gigantic Thermopower for Low-Grade Heat Harvesting

“…Figure f compares the Seebeck coefficient and ionic conductivity of previously reported i-TE materials based on individual thermodiffusive effects. It can be seen that the comprehensive performances of CaBC/NaCl hydrogel are much greater than those previously reported for i-TE materials. ,,,,− We also calculated the ionic power factor (PF) of the hydrogel, as shown in Figure S12 in the Supporting Information. When the NaCl concentration in the hydrogel was 3 M, we obtained the best PF of 15.11 mW m –1 K –2 , because of its high ionic conductivity of 204.2 mS cm –1 and a high Seebeck coefficient of −27.2 mV K –1 .…”

Soret Effect of Ionic Liquid Gels for Thermoelectric Conversion

“…The ionogels should have a high ionic conductivity and high ionic Seebeck coefficient to have high thermoelectric properties. A couple of methods were recently reported to increase the ionic conductivity and/or the ionic Seebeck coefficient. − The ZT i value of ionogels was rapidly increased to >6 …”