Simultaneous Enhancement of Energy and Power Density of Reduced Graphene Oxide by the Effect of Dispersed Metal Oxide Nanoparticles in the Electrolyte

Abstract

Few-layered reduced graphene oxide (RGO) is prepared from graphite by chemical exfoliation method. In half cell, RGO electrode delivers a specific capacitance value of 41 mF cm−2 at 0.5 mA cm−2 in 1.0 M KOH. An attempt is made to improve the capacitance properties of RGO by widening the operating voltage window and improving the charge storage capability through the use of metal oxide nanoparticles as electrolyte additives. The specific capacitance of RGO increases to 62 mF cm−2 and 87 mF cm−2 when ZnO and SiOx nanoparticles were uniformly dispersed in the electrolyte, respectively, at 0.5 mA cm−2. For a power density of 1.5 mW cm−2, the symmetric supercapacitor assembled using ZnO and SiOx nanofluid electrolyte delivers an energy density of 2.6 μWh cm−2 and 3.03 μWh cm−2, respectively, which is 2.7 and 3.1 times the value of energy density obtained for symmetric supercapacitor assembled using KOH electrolyte. The nanofluid electrolytes show high stability even after 60 d and the electrochemical performance of RGO is reproducible in the aged nanofluid electrolytes. The RGO electrode shows stable cycling for the tested number of 10000 cycles in all the electrolytes.

Nickel Hydroxide Nanofluid Cathodes with High Solid Loadings and Low Viscosity for Energy Storage Applications

“…Liquids are flowable, conformable in shape and have convective mechanisms for energy, mass, and momentum transfer. Solids dispersed inside nanofluids can provide novel functionality but also change fluid dynamics, viscosity, thermal conductivity, density and specific heat [14][15][16][17][18][19][20].…”

Acetonitrile-Free Organic Electrolyte for Textile Supercapacitor Applications

“…With more devices comes more complexity and consideration must be taken over the balancing within the TSC string. To increase the operating window for aqueous electrolytes, groups have made use of additives, (such as Bharathidasan et al 23 use of dispersed SiOx nano particles) or asymmetric electrodes (such as Guo et al 24 use of nitrogen doped carbon sheets and CoNiO2).…”

“…With more devices comes more complexity and consideration must be taken over the balancing within the TSC string. To increase the operating window for aqueous electrolytes, groups have made use of additives, (such as Bharathidasan et al 23 use of dispersed SiO x nano particles) or asymmetric electrodes (such as Guo et al 24 use of nitrogen doped carbon sheets and CoNiO 2 ). The SiO x nanoparticles led to a three times improvement in the energy density, while the asymmetric electrodes increased the potential window of the KOH electrolyte to 1.5 V. However, these strategies again add complexity to the system.…”

A Rational Approach to Suppress Hydrogen Evolution Reaction and its Concurrent Zinc Corrosion in Zinc-air Batteries: A Uniform Dispersion of Carbon Nanodots in the Electrolyte

“…Due to its enhanced Brownian motion and superior heat transfer capabilities, nanofluid (uniformly dispersed nanomaterial in a base fluid) is instrumental in improving the performance of redox flow batteries, ZABs, fuel cells and supercapacitors. [27][28][29][30][31][32] Carbon nanodots (CNDs) possess many advantageous features, including strong fluorescence, chemical inertness, easy functionalization, low toxicity, good biocompatibility, etc. 33,34 Herein, CNDs are dispersed in 6 M KOH (CNF) and used to suppress HER and zinc corrosion.…”