A flexible electrode of TiO2 nanowire arrays modified with graphene for solid-state cable-type supercapacitors

Solid-state cable-type supercapacitors (SSCTSs) have a wide application in wearable and flexible electronic devices. The fiber-shaped electrode of fabricating TiO2 nanowire arrays (NWAs) on Ti wire is widly used in flexible electronic devices. For improving the conductivity, reduced graphene oxide (rGO) nanosheets are prepared on the surface of TiO2 NWAs by a simple electrophoretic deposition method and NaBH4 treatment. The electrochemical tests reveal that this TiO2/rGO electrode has an excellent capacitive property than pure TiO2 electrode in the optimum potential window (-0.4 similar to 0.6 V). Two similar TiO2/rGO electrodes with Poly (vinyl alcohol)-LiCl solid-state electrolyte are assembled SSCTSs, which deliver a specific capacitance as high as 60.8 mu F cm(-1) at 5 mu A cm(-1) and a high energy density of 12.2 mWh cm(-1) with a wide potential window from 0 to 1.2 V. Furthermore, this SSCTS exhibits outstanding banding performance at different state and long cycle life. These results demonstrate that fiber-shaped TiO2/rGO electrode is promising for high-performance wearable and flexible electronic devices.