High-Performance All-Solid-State Flexible Asymmetric Supercapacitor Device Based on a Ag–Ni Nanoparticle-Decorated Reduced Graphene Oxide Nanocomposite as an Advanced Cathode Material

Abstract

The development of wearable electronic devices and energy storage devices that are thin, lightweight, and flexible has led to the fabrication of flexible all-solid-state supercapacitors with skyscraping mechanical endurance and foldability. Herein, for the first time, we have delineated the assembly of a high-performance mechanically flexible all-solid-state asymmetric supercapacitor device from the nanocomposite comprising (Ag0.50Ni0.50)90-rGO10 and pure rGO as the cathode and anode electrode, respectively. Polyvinyl alcohol (PVA) gel containing 3 M KOH is used as the electrolyte and separator. This device delivers a high power density of 1700 W kg–1 without compromising with an energy density value of 49 W h kg–1 which is much higher in comparison to many of the existing supercapacitors in the market and substantive findings in the literature. Also, when the fabricated device is subjected to 5000 galvanostatic charge–discharge (GCD) cycles, a retention of ∼97% of the initial specific capacitance value is observed, displaying its high cycling stability. The omnidirectional mechanical robustness of this supercapacitor makes it flexible to that extent that it tends to exhibit high electrochemical performance even under extreme conditions and the specific capacitance value is pragmatically left unmodified when the device was subjected to different bending conditions. This device showcased its practical application by illuminating seven light-emitting diodes (LEDs) and appeared as an attractive energy storage unit for handy devices.

Biomass-Derived Porous Carbon-Anchoring MnFe2O4 Hollow Sphere and Needle-Like NiS for a Flexible All-Solid-State Asymmetric Supercapacitor

“…The CV profiles of PC and MnFe 2 O 4 -NiS-PC at 10 mV s –1 in the potential range of −1 to 0 and 0–0.55 V, respectively, are shown in Figure a. The quasirectangular shape of the CV curve (Figure S11a) and nearly symmetrical GCD curves of PC (Figure S11b) reflected its EDLC nature and rapid current response . The pseudocapacitive nature of MnFe 2 O 4 -NiS-PC was reflected in its CV profile.…”

“…The quasirectangular shape of the CV curve (Figure S11a) and nearly symmetrical GCD curves of PC (Figure S11b) reflected its EDLC nature and rapid current response. 43 The pseudocapacitive nature of MnFe 2 O 4 -NiS-PC was reflected in its CV profile. The CV profiles of the MnFe 2 O 4 -NiS-PC//PC asymmetric supercapacitor exhibited a stable operating voltage up to 1.5 V (Figure 4b).…”

Dual-Purpose CuFe2O4-rGO-Based Nanocomposite for Asymmetric Flexible Supercapacitors and Catalytic Reduction of Nitroaromatic Derivatives

“…The well-retained CV profile even with rising scan rate and the nearly symmetric triangular shape of the GCD curves indicated the good rate performance and balanced charge storage with remarkable electrochemical reversibility (Figure 3e). 8,48 The C S value obtained from the GCD measurements was 113 F g −1 at a current density of 4 A g −1 , and it was observed that the C S value declined with rising current density. This is due to the depressed ion penetration at comparatively higher current densities, causing incomplete redox reaction at the electrode surface/electrolyte interface.…”

“…Several review papers are available where fundamentals of SCs, categories of SC devices, different types of electrode materials, electrolytes, electrochemical reactions involved, fabrication of SCs, etc., have been discussed in detail. − Among various supercapacitors, high-performance all-solid-state flexible supercapacitors have acquired immense academic and technological attention to satisfy the demand for compact, flexible, and wearable electronic products. Legerity and superior electrochemical performance have led to the improved miniaturization and wearability of these flexible devices. − …”

A high-performance flexible energy storage device from biomass-derived porous carbon supported MnCo2O4 nanorods and MnO2 nanoscales

“…Beyond 1.6 V, the CV curve of the ASC device showed an irregularity in the shape as well as an unwanted peak (marked by a pink circle) due to the thermodynamic breakdown of water. 51 Fig. 6c depicts the CV profiles of the MCO-MnO 2 -PC‖PC device in the 0 to 1.6 V range at numerous scan rates.…”