All graphene electrode for high‐performance asymmetric supercapacitor

Abstract

Electrode imbalance" is one of the major issues that hinders the potential performance of asymmetric supercapacitors (ASCs), which arises mainly due to the huge dissimilarities of the electrodes microstructures. Herein, an "allgraphene" electrode system is designed by simple chemo-thermal modification of graphene oxide. Chemically functionalized graphene (FG) cathode and two anodes based on thermally reduced graphene oxide (TrGO) and iodine-doped graphene (IG) prepared via simple synthetic routes, followed by assembling into ASCs. The ASC comprising FG cathode-IG anode delivers phenomenally high energy-power (E-P) density (91 W h kg −1 and 424.95 W kg −1 ) and a good capacitance retention after 10 000 cycles. This outcome is accredited to the similar chemistry of electrodes resulting in a minimal electrode imbalance.The developed scheme has capacity to be employed as all-graphene hybrid energy storage system outputting enhanced performance and cyclic stability.asymmetric supercapacitor, all-graphene electrode system, functionalized graphene, iodinedoped graphene, ultra-high energy density

Graphene/ β‐ MnO 2 composites—synthesis and its electroanalytical properties study in the Mg storage battery

“…Graphene is a single layer with a two-dimensional (2D) structure of hexagonal sp 2 carbon arrays. 8 Graphene has excellent thermal conductivity (~5000 W/ m / k), and it has received considerable research interest for the preparation of superior electrode materials. [9][10][11][12] Graphene has a desirable application because of its high optical transmittance, unique structural features, high theoretical surface area (2675 m 2 /g) and good electrical properties, 13 which is an intrinsic carrier mobility of 200 000 cm 2 /Vs.…”

“…Graphene is a single layer with a two‐dimensional (2D) structure of hexagonal sp 2 carbon arrays 8 . Graphene has excellent thermal conductivity (~5000 W/m / k), and it has received considerable research interest for the preparation of superior electrode materials 9‐12 .…”

Preparation of activated biomass carbon from pine sawdust for supercapacitor and CO 2 capture

“…Zhu et al found that the biomass carbons from ginkgo leaves by KOH activation exhibited the highest specific capacitance of 374 F·g −1 at 0.5 A·g −1 compered to activating agent of ZnCl 2 and H 3 BO 3 . Siddique et al used graphene as an electrode for the performance of supercapacitor and found that it delivers a high energy density of 91 Wh·kg −1 and a power density of 424.95 W·kg −1 . Chen et al reported that chitin‐based carbon owned high electrochemical performance.…”

A hybrid composite of rGO / TiO 2 as a double layer electrode with improved capacitance performance

“…[8][9][10] Graphene makes an ideal SC support materials to prepare HCs as it has the highest theoretical conductivity and capacitance values as compared to the other carbonaceous materials. 11 Therefore, it is widely used as conductive backbone to lodge TMOs as active electrode components. Nevertheless, the key to make graphene-TMOs hybrid materials lies in compositing them in a way to ensure maximum area of contact which then enhances the electrode work function in electrolytes to deposit maximum numbers of ions on the surface of electrodes.…”

“…Graphene makes an ideal SC support materials to prepare HCs as it has the highest theoretical conductivity and capacitance values as compared to the other carbonaceous materials 11 . Therefore, it is widely used as conductive backbone to lodge TMOs as active electrode components.…”