Graphene foam functionalized with electrodeposited nickel hydroxide for energy applications

Abstract

The need of new systems for the storage and conversion of renewable energy sources is fueling the research in supercapacitors. In this work, we propose a low temperature route for the synthesis of electrodes for these supercapacitors: electrodeposition of a transition metal hydroxide --Ni(OH)2 on a graphene foam. This electrode combines the superior mechanical and electrical properties of graphene, the large specific surface area of the foam and the large pseudocapacitance of Ni(OH)2. We report a specific capacitance up to 900 F/g as well as specific power and energy comparable to active carbon electrodes.

Hybrid Films of Ni(OH)2 Nanowall Networks on Reduced Graphene Oxide Prepared at a Liquid/Liquid Interface for Oxygen Evolution and Supercapacitor Applications

“…In addition, low cost, earth abundance, facile preparation, layered structure and theoretically high specific capacitance add to their value as potential materials . However, poor electronic conductivity, large volumetric expansion and aggregation during elelctrochemcial cycling limit the electron transport affecting the reaction kinetics ,. Henceforth, to address all these problems, one feasible and effective approach is to fabricate novel hybrid nanostructured materials.…”

“…Of particular interest is graphene and its derivatives such as reduced graphene oxide (rGO) possessing high surface area, good mechanical and thermal stability and have been widely investigated for electrochemical applications , Compared to the numerous reports of Ni(OH) 2 nanostructures for supercapacitor applications, studies on their oxygen evolution activity are less . Ni(OH) 2 in the form of nanoparticles, nanosheets supported on Ni foam, nanoplates on multiwalled carbon nanotubes (MWCNTs), nanosheets doped with other active metals on Ni foam, etc have been reported for OER ,,.…”

“…[13] However, poor electronic conductivity, large volumetric expansion and aggregation during elelctrochemcial cycling limit the electron transport affecting the reaction kinetics. [14,15] Henceforth, to address all these problems, one feasible and effective approach is to fabricate novel hybrid nanostructured materials. The growth of electrocatalysts directly on conductive substrates such as graphene nanosheets, carbon nanofibres and nanotubes and Ni foam is an effective way to improve the capacitive performance and cycling stability of the electrode materials by enhancing the electrical conductivity.…”

“…[15-17,20À 23] Compared to the numerous reports of Ni (OH) 2 nanostructures for supercapacitor applications, studies on their oxygen evolution activity are less. [11][12][13][14][15][16][17] Ni(OH) 2 in the form of nanoparticles, nanosheets supported on Ni foam, nanoplates on multiwalled carbon nanotubes (MWCNTs), nanosheets doped with other active metals on Ni foam, etc have been reported for OER. [18,19,[24][25][26][27] In a recent report, Zhou et al has shown that the in-situ growth of βNi(OH) 2 nanoplates on MWCNTs improves OER activity when compared to bare βNi (OH) 2 nanoplates and physical mixture of nanoplates and MWCNTs.…”

Recent trends in graphene supercapacitors: from large area to microsupercapacitors

“…(a) Within the family of 3D sponge graphene structures, 35 graphene foam (GF) obtained from the reduction of graphene oxide (rGO) by chemical methods [36][37][38][39] and by chemical vapor deposition (CVD) [40][41][42][43] represents the focus in Section 2.1. The improvement of its energy density and operating voltage window as a supercapacitor by lling it with other carbon-based materials such as carbon nanotubes (CNTs) [44][45][46] or pseudocapacitive materials such as metal oxides, [47][48][49] metal hydroxides [50][51][52][53] and conductive polymers [54][55][56][57] is also discussed within the section.…”