Co-sputtered V2O5–TiN composite on Ag-network current collector for high-performance flexible transparent thin-film supercapacitors

Abstract

Next-generation wearables require extremely capable electrochemical energy-storage devices that exhibit improved performance with high flexibility and transparency. Herein, we present a highly flexible and transparent electrochemical thin-film supercapacitor electrode fabricated by co-sputtering V2O5 and TiN on an Ag-network-based current collector. The electrodes' physical properties, optical properties, and structural morphologies are studied using X-ray diffraction, UV–visible spectroscopy, and scanning electron microscopy, respectively. A symmetric device is fabricated using V2O5 and TiN on an Ag network, and the TiN sputter power is varied to optimize the performance. The device performance of the co-sputtered electrodes at various composition ratios is studied. The optimized V2O5–TiN (200−40)/Ag electrode device with pseudocapacitive behavior delivers an excellent areal specific capacitance of 98.66 mF cm–2 at a current density of 4 mA cm–2 with a charge retention of 90.12 % after 6000 cycles. The V2O5–TiN (200−40)/Ag electrode device outperforms other reported electrodes, with an energy density and power density of 30.83 μWh cm–2 and 2999.67 μW cm–2, respectively, and excellent mechanical stability.