Super Long‐Life Supercapacitors Based on the Construction of Nanohoneycomb‐Like Strongly Coupled CoMoO₄–3D Graphene Hybrid Electrodes

Abstract

Nanohoneycomb-like strongly coupled CoMoO4 -3D graphene hybird electrodes are synthesized for supercapacitors which exhibit excellent specific capacitance and superior long-term cycle stability. The supercapacitor device can power a 5 mm-diameter LED efficiently for more than 3 min with a charging time of only 2 s, and shows high energy densities and good cycle stability.

Two-dimensional NiCo2O4nanosheet-coated three-dimensional graphene networks for high-rate, long-cycle-life supercapacitors

“…The peak current increasing linearly with the increment of the scan rate also suggests that the rates of electronic and ionic transportation were rapid enough with respect to the scan rates. 22 The selected galvanostatic charge/discharge curves of the NiCo 2 O 4 NS/3DGN electrode (Fig. 4b) at different current densities in the potential window of 0-0.4 V exhibit the discharge voltage plateaus at around 0.2-0.1 V, which is in good agreement with the CV curves (Fig.…”

“…46 Lastly, the strong coupling between NiCo 2 O 4 NS and 3DGN renders good mechanical adhesion and electrical connection, avoiding the use of polymer binders and conductive additives and leading to enhanced electrochemical kinetics, which is good for high-rate capability and long-term cycling performance of supercapacitors. 12,22,27 In summary, we have successfully fabricated high-capacitance, high-rate, and long-cycle-life supercapacitors by synthesis of thin 2D NiCo 2 O 4 NS with a thickness of ∼6.4 nm on 3DGN. The novel NiCo 2 O 4 NS/3DGN hybrid demonstrates excellent electrochemical performances including ultrahigh specific capacitances as well as excellent rate capability of 2173 and 954 F g −1 at high current densities of 6 and 200 A g −1 , respectively, and superior long-term cycling stability with only 6% capacitance loss after 14 000 cycles at 100 A g −1 , which is obviously superior to most of the previously reported pseudocapacitor electrodes (Table S1 in ESI †).…”

NiCo2S4 Nanosheets Grown on Nitrogen‐Doped Carbon Foams as an Advanced Electrode for Supercapacitors

“…Greatly enhanced performance has kindled the interest of researchers in the fi eld of 3D electrode architectures designs, such as copper pillar array, [ 31 ] nickel network, [ 32,33 ] stainless steel mesh, [ 34 ] carbonaceous interpenetrating structures. [ 35 ] The rigid electrode with metals as current collectors lead to the devices less fl exible, and they also have a low energy density. Carbon nanotubes sponge and graphene foams have been recently fabricated using chemical vapor deposition and used as electrode architectures for supercapacitors.…”

Role of anions on structure and pseudocapacitive performance of metal double hydroxides decorated with nitrogen-doped graphene

“…A linear increase in peak current was observed with the increasing scan rate, signifying that the electronic and mass transfer is fast enough with respect to the scan rates. As scan rate increases from 5 to 100 mV s −1 , a small shift in the redox peak position confirms that the hybrid still keeps its structure and high conductivity, and a pair of redox peak still exists in the CV curves, suggesting that the NiCoDH@NG hybrid electrode is capable for fast redox reactions while most of the other reported materials show large shift because of the increasing diffusion barrier to ions [22,27]. Furthermore, linear voltage plateaus are observed in constant charge-discharge curves of NiCoDH@ NG (Fig.…”