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 TiO 2 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 TiO 2 NWAs by a simple electrophoretic deposition method and NaBH 4 treatment. The electrochemical tests reveal that this TiO 2 /rGO electrode has an excellent capacitive property than pure TiO 2 electrode in the optimum potential window (− 0.4~0.6 V). Two similar TiO 2 /rGO electrodes with Poly (vinyl alcohol)-LiCl solid-state electrolyte are assembled SSCTSs, which deliver a specific capacitance as high as 60.8 μF cm −1 at 5 μA 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 TiO 2 /rGO electrode is promising for high-performance wearable and flexible electronic devices.