Synthesis of CoS_x/TiO₂ nanotubes hybrid electrode for application in supercapacitors

TiO₂ nanotubes are widely recognized as promising electrode materials for supercapacitor application due to their excellent stability. In this study, binder free CoS_x/TiO₂ nanotubes composite electrodes materials were fabricated on titanium sheet by constant piezoelectric deposition under different deposition time. The electrochemical characterization indicates that the CoS_x/TiO₂ nanotubes composite deposited for 1200 s demonstrated the best electrochemical performance. At a current density of 3 mA/cm², the composite electrode exhibits a mass specific capacitance of 401 F/g and an areal capacitance of 16.64 F/cm². In addition, aqueous and all-solid symmetric supercapacitors were prepared using CoS_x/TiO₂ nanotubes composite electrode materials. The maximum power density of water-symmetrical supercapacitors is 4500 μW/cm², and the maximum energy density is 756.88 μWh/cm². The maximum power density and maximum energy density of the all-solid-state symmetrical supercapacitor are 4125 μW/cm² and 629.4 μWh/cm², respectively. By connecting two identical supercapacitor in series, the stored energy was able to power a red LEDs for 9 min and 7 min, respectively. These results highlight the promising application potential of CoS_x/TiO₂ nanotubes electrode materials for supercapacitor systems.