(Invited) All-in-One Graphene Composite-Based Fiberwearable Supercapacitor

Abstract

Graphene fibers (GF) have generated great interest in wearable electronics applications due to their excellent mechanical flexibility and superior electrical conductivity. Herein, an all-in-one graphene and MnO2 composite hybrid supercapacitor fiber device has been designed and tested. The unique coaxial design of this device enables large scale production and avoids the risk of short circuiting. The backbone of the device consists of GF that not only provides a durable scaffold for the entire device, but also ensures fast electron transfer during charge-discharge. The introduction of a MnO2 (200 nm in length) hierarchical nanostructured film, with abundant active sites contacting the interface of the PVA/H3PO4 gel electrolyte, enhanced the pseudocapacitance dramatically compared to the graphene-only device. The entire device displays outstanding mechanical strength as well as good electrocapacitive performance with a volumetric capacitance of 29.6 F cm-3 at 2 mv s-1. The capacitance of the device maintained under bending testing from 0° to 150°, while the capacitance retention was kept 93% after 1000 cycles. These unique features make this device a promising candidate for applications in wearable fabric supercapacitors.