Highly Conductive Self-Healable Rhenium Oxide–Polytetrahydrofuran Composite for Resilient Flexible Electrode

The newly introduced conductive rhenium oxide–polytetrahydrofuran (ReOx–PTHF) exhibits high electrical conductivity (6.4 S/cm) and autonomous self-healing properties. ReOx–PTHF can be easily synthesized by dissolving Re2O7 in the tetrahydrofuran (THF) solvent and waiting for over 24 h without further treatment. The synthesized ReOx–PTHF can be prepared as a gummy lump and thin film. Both mechanically cut ReOx–PTHF chunks and thin films can be successfully self-healed, and their electrical conductivity recovered after self-healing, although conventional PTHF does not exhibit electrical conductivity and self-healing properties at all. Ion–dipole and coordinative interactions by the ReO4– and ReO3 particles in the ReOx–PTHF significantly contribute to their self-healing properties and enhance the electrical conductivity of PTHF. Thus, ReOx–PTHF can be applied to self-repairing electronic circuits on the macroscale and microscale. Significantly, the self-healing properties and high electrical conductivity of ReOx–PTHF prevent severe loss of electrical conductivity of the thin metal film in flexible devices by mechanical strain when this polymer is simply spin-coated on the flexible electrodes. Thus, ReOx–PTHF-coated flexible electrodes show excellent capability as resilient flexible electrodes, which can retain their original electrical conductivity even after 10 000 bending cycles. Further, the ReOx–PTHF is not swellable and decomposable in aqueous media, sweat-like saltwater, and after it was exposed for over a month under ambient conditions. Therefore, ReOx–PTHF is a promising material as a resilient electrode in flexible and wearable electronics.