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

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.