Screen printed textile electrodes using graphene and carbon nanotubes with silver for flexible supercapacitor applications

Abstract

The eco-friendly conductive cotton textile is promising alternatives for the flexible substrates in wearable devices since the cotton is as an inexpensive natural fabric material and compatible in modern portable electronics with adequate electrical conductivity. In this work, flexible conductive cotton-based electrodes are prepared via a screen-printing method using the carbonaceous nanomaterials such as carbon nanotubes (CNTs) and graphene with an additional component of conductive silver (Ag) powder and textile ink. The prepared conductive cotton electrodes exhibit lower sheet resistance (<10 Ω) along with superior mass loading (20-30 mg.cm-2). On the basis of the performance of cotton electrodes prepared, an all-solid-state flexible supercapacitor device was successfully fabricated which exhibits a high specific areal capacitance of 677.12 mF.cm-2 at 0.0125 mA.cm-2 for a suitable electrode composition (60% of Ag and 40% CNTs) using a PVA-KOH gel electrolyte. The flexible device endures a stable electrochemical performance under severe mechanical deformation using different bending angles (0°, 30°, 45°, 60° and 90°) of the device and possesses excellent cyclic stability with the capacitance retention of ~80% even after 3000 CV cycles.