Freestanding\nGraphene Paper Supported Three-Dimensional\nPorous Graphene–Polyaniline Nanocomposite Synthesized by Inkjet\nPrinting and in Flexible All-Solid-State Supercapacitor

Abstract

Freestanding paper-like electrode\nmaterials have trigged significant\nresearch interest for their practical application in flexible and\nlightweight energy storage devices. In this work, we reported a new\ntype of flexible nanohybrid paper electrode based on full inkjet printing\nsynthesis of a freestanding graphene paper (GP) supported three-dimensional\n(3D) porous graphene hydrogel (GH)–polyaniline (PANI) nanocomposite,\nand explored its practical application in flexible all-solid-state\nsupercapacitor (SC). The utilization of 3D porous GH scaffold to load\nnanostructured PANI dramatically enhances the electrical conductivity,\nthe specific capacitance and the cycle stability of the GH–PANI\nnanocomposite. Additionally, GP can intimately interact with GH–PANI\nthrough π–π stacking to form a unique freestanding\nGP supported GH–PANI nanocomposite (GH–PANI/GP) with\ndistinguishing mechanical, electrochemical and capacitive properties.\nThese exceptional attributes, coupled with the merits of full inkjet\nprinting strategy, lead to the formation of a high-performance binder-free\npaper electrode for flexible and lightweight SC application. The flexible\nall-solid-state symmetric SC based on GH–PANI/GP electrode\nand gel electrolyte exhibits remarkable mechanical flexibility, high\ncycling performance and acceptable energy density of 24.02 Wh kg^–1 at a power density of 400.33 W kg^–1. More importantly, the proposed simple and scale-up full inkjet\nprinting procedure for the preparation of freestanding GP supported\n3D porous GH-PANI nanocomposite is a modular approach to fabricate\nother graphene-based nanohybrid papers with tailorable properties\nand optimal components.