Intrinsically self-healable, stretchable thermoelectric materials with a large ionic Seebeck effect

While the thermoelectric (TE) generator has attracted tremendous attention, the development of wearable TE generators with stretchability and self-healability has been a significant challenge. Herein, we report intrinsically self-healable and stretchable ternary ionic TE hybrid materials, composed of a conjugated polymer (polyaniline), a non-conjugated anionic polyelectrolyte (poly(2-acrylamido-2-methyl-1-propanesulfonic acid)), and phytic acid. The proposed materials exhibit an excellent ionic figure-of-merit (ZT_i) as well as remarkable stretchability (up to ∼750%) and autonomous self-healability without any external stimuli. The ionic TE performance was sustainable under severe deformation (50% strain) and multiple self-healing processes (30 cycles), which is the first demonstration of such performance. The ZT_i of the stretchable and self-healable ternary TE hybrids is 1.04. Moreover, a self-healable and stretchable ionic thermoelectric capacitor device is also demonstrated using the ternary TE hybrid.