No abstract

Ionic thermoelectrics show great potential in thermal sensing owing to their ultrahigh thermopower, low cost, and ease in production. However, the lack of effective n-type ionic thermoelectric materials seriously hinders their applications. Here, we report giant and bidirectionally tunable thermopowers within an ultrawide range from −15 to +17 mV K −1 in solid ionic liquid-based ionogels. Particularly, a record high negative thermopower of −15 mV K −1 is achieved in the ternary ionogel, rendering it among the best n-type ionic thermoelectric materials under the same condition. A thermopower regulation strategy through ion doping to selectively induce ion aggregates to enhance ion-ion interactions is proposed. These selective ion interactions are found to be decisive in modulating the sign and magnitude of the thermopower in the ionogels. A prototype wearable device integrated with 12 p-n pairs is demonstrated with a total thermopower of 0.358 V K −1 , showing promise for ultrasensitive thermal detection.

The phase-structure dependent ion transport networks comprised of Oct–Tet and Oct–Oct pathways in Na3YI6 broaden the diffusion channels and provide rational guidance for the design of halide-based Na superionic conductors.

No abstract