Flexible Asymmetrical Solid-State Supercapacitors Based on Laboratory Filter Paper

In this study, a flexible asymmetrical all-solid-state supercapacitor with high electrochemical performance was fabricated with Ni/MnO2—filter paper (FP) as the positive electrode and Ni/active carbon (AC)—filter paper as negative electrode, separated with poly(vinyl alcohol) (PVA)–Na2SO4 electrolyte. A simple procedure, such as electroless plating, was introduced to prepare the Ni/MnO2–FP electrode on the conventional laboratory FP, combined with the subsequent step of electrodeposition. Electrochemical results show that the as-prepared electrodes display outstanding areal specific capacitance (1900 mF/cm2 at 5 mV/s) and excellent cycling performance (85.1% retention after 1000 cycles at 20 mA/cm2). Such a flexible supercapacitor assembled asymmetrically in the solid state exhibits a large volume energy density (0.78 mWh/cm3) and superior flexibility under different bending conditions. It has been demonstrated that the supercapacitors could be used as a power source to drive a 3 V light-emitting diode in...