High Thermopower of Agarose-Based Ionic Thermoelectric Gel Through Micellization Effect Decoupling the Cation/Anion Thermodiffusion

Ionic thermoelectric (i-TE) gels can have a high thermopower, if the thermodiffusion of mobile cation/anion is decoupled, attracting increasing attentions. Herein, it is shown a high p-type i-TE thermopower of 41.8 mV K-1 in agarose-based ionic thermoelectric gels of AG-x Na:DBS (AG: agarose, Na:DBS: sodium dodecyl benzene sulfonate). The exclusively high thermopower is relative to the successfully decoupling the thermodiffusion of cation Na+ and anion DBS-. A unique porous structure is formed due to the micellization of the amphiphilic DBS- with the hydrophilic benzenesulfonic group attached to the hydrous agarose gel chains, while the hydrophobic alkyl chain point to the pore centers. As a result, the DBS- micelles are almost immobile as compared with Na+, which can be reconsidered as a part of the gel matrix. The work shines a light on decoupling of cation/anion thermodiffusion through tailoring the microstructure of the quasi-solid i-TE materials.