Electrophoresis deposition of flexible and transparent silver nanowire/graphene composite film and its electrochemical properties

Abstract

Silver nanowire (Ag NW)/graphene composite films were fabricated on polyethylene terephthalate (PET) substrates using an electrophoresis method, making graphene sheets closely contact with NW networks. As electrophoresis voltage increased from −1 V to −10 V, the transmittance and sheet resistance of the composite film changed in the range of 64.8%–35.2% and 0.98 Ω/sq-6.61 Ω/sq (initial values are 75.7% and 0.77 Ω/sq). Combined advantages of two materials, the stability of the Ag NW film was greatly enhanced due to protection of the graphene layer, and the conductivity of the graphene electrode was remarkably improved ascribed to introduction of the interconnected networks. The areal and specific capacitance of the composite film increased from 1.22 mF/cm2 to 7.6 mF/cm2 and decreased from 108.4 F/g to 25.7 F/g at 100 mV/s in a 1 M LiClO4 solution, as the electrophoresis voltage increased from −1 V to −10 V. Furthermore, the Ag NW/graphene composite film exhibited a good long-term cycling stability with 82.6% capacitance retention after 2500 cycles. Additionally, a symmetric supercapacitor using the Ag NW/graphene films as electrodes exhibited symmetric galvanostatic charge-discharge and similar CV curves under flat and bent conditions, indicating that the fabricated electrode could be considered as one of excellent candidates in flexible and transparent supercapacitors.