Highly Hydrophobic, Self‐Healing, and Stretchable N‐type Ionogels for High‐Performance Wearable Thermoelectrics

ABSTRACT Flexible and wearable electronics demand materials that combine environmental stability, mechanical resilience, and efficient energy harvesting. Here, we report a highly hydrophobic, self‐healing, and stretchable n‐type ionic thermoelectric ionogel synthesized via one‐step UV polymerization of 2,2,3,3,3‐pentafluoropropyl acrylate (PFPA) and acrylamide (AAm) in the hydrophobic ionic liquid (IL) 1‐ethyl‐3‐methylimidazole bis(trifluoromethanesulfonyl)imide ([EMIM][TFSI]). The fluorine‐rich copolymer network and dynamic noncovalent interactions enable exceptional multifunctionality: ultrahigh stretchability (1659% elongation), rapid self‐healing (6 h), underwater adhesion, and thermal stability up to 300°C. The ionogel achieves a thermopower of −11.99 mV K −1 , ionic conductivity of 24.46 mS cm −1 , and a power factor of 351 µW m −1 K −2 , outperforming most reported n‐type ionogels. Integrated into an ionic thermoelectric capacitor, it delivers a maximum power density of 0.091 W m −2 , demonstrating practical viability for low‐grade heat harvesting. This work establishes a new design paradigm for multifunctional ionogels, paving the way for next‐generation wearable thermoelectric devices and robust energy harvesters for harsh environments.