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

Abstract

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, ReO4-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.