High Energy Density Asymmetric Supercapacitor Based on NiOOH/Ni3S2/3D Graphene and Fe3O4/Graphene Composite Electrodes

Abstract

The application of the composite of Ni3S2 nanoparticles and 3D graphene as a novel cathode material for supercapacitors is systematically investigated in this study. It is found that the electrode capacitance increases by up to 111% after the composite electrode is activated by the consecutive cyclic voltammetry scanning in 1 M KOH. Due to the synergistic effect, the capacitance and the diffusion coefficient of electrolyte ions of the activated composite electrode are ca. 3.7 and 6.5 times higher than those of the Ni3S2 electrode, respectively. Furthermore, the activated composite electrode exhibits an ultrahigh specific capacitance of 3296 F/g and great cycling stability at a current density of 16 A/g. To obtain the reasonable matching of cathode/anode electrodes, the composite of Fe3O4 nanoparticles and chemically reduced graphene oxide (Fe3O4/rGO) is synthesized as the anode material. The Fe3O4/rGO electrode exhibits the specific capacitance of 661 F/g at 1 A/g and excellent rate capability. More importantly, an asymmetric supercapacitor fabricated by two different composite electrodes can be operated reversibly between 0 and 1.6 V and obtain a high specific capacitance of 233 F/g at 5 mV/s, which delivers a maximum energy density of 82.5 Wh/kg at a power density of 930 W/kg.

Supercapacitor Electrode Based on Nano-Vanadium Nitride Incorporated on Porous Carbon Nanospheres Derived from Ionic Amphiphilic Block Copolymers & Vanadium-Contained Ion Assembly Systems

“…And for the rate capability, the PCNS@VNNP-0.6 is the best. These data confirm that the r V/P value plays an important role in electrochemical storage process: too high or low r V/P value cannot 15 obtain a high supercapacitor performance due to the failure to fabricate the rational superstructure as mentioned above. To simulate actual device behavior, asymmetrical cells with a two-electrode configuration were constructed to fabricate PCNS@VNNP//NiO hybrid supercapacitors.…”

“…Energy density can be improved by enhancing high capacitance and providing increased cell potential of the full devises according to E=0.5 CV 2 [15,16]. Recently, metal nitrides, for instance, iron nitride (Fe 2 N), molybdenum nitride (MoN), titanium nitride (TiN), and vanadium nitride (VN) were given much interesting owing to its superb electrical conductivity (4000-55 500 S/cm), high capacitance (>200 F/g), and wide operating potential window (0.8-3 V) [17 -19].…”

Ni Foam‐Ni3S2@Ni(OH)2‐Graphene Sandwich Structure Electrode Materials: Facile Synthesis and High Supercapacitor Performance

“…Figure 3b shows the Ni 2p emission spectrum with two major peaks centered around 873 and 855.4 eV,w ith as pin-energy separation of 17.6 eV,c orresponding to Ni 2p 1/2 and Ni 2p 3/2 ,r espectively.T hese peaks are characteristic of aN i(OH) 2 phase andi ng ood agreement with the previousl iterature. [15] Figure 3c depicts the high-resolution spectrum for the O1sr egion, reveal- ing three oxygen contributions. The binding energies at 852 eV and 869 eV are typicalc haracteristic peaks of Ni 3 S 2 .…”

“…After comparison, the optimizedf irst and second hydrothermal reactiont imes wered etermined to both be 2h.T herefore, in the following section, the electrochemical analysis was performed on the samples of NF-N-2h, NF-NN-2h, and NF-NN-G-5mg (2 h). [19] The corresponding reversible reactions can be described by Equations (1)and (2): [15,20] Ni 3 S 2 þ 3OH À $ Ni 3 S 2 OH ðÞ 3 þ 3e À ð1Þ Figure 7a shows the cyclic voltammogram curves( CV) of NF-N-2h, NF-NN-2h, and NF-NN-G-5mg electrodes, which were measured at as can rate of 10 mV s À1 over the voltage range 0 to 0.7 V. Ap air of obvious strong redox peaks can be observed in all curves, which are attributed to the Faradaic reactiont hat bringsp seudo-capacitancec haracteristics in the electrochemical reaction.…”

Mechanical alloying synthesis of Ni 3 S 2 nanoparticles as electrode material for pseudocapacitor with excellent performances

“…Moreover, the anodic peaks shift towards positive potential and the cathodic peaks shift towards negative potential can be observed with the increasing of scan rates, this is caused by the strengthened electric polarization generated during the charge/discharge process [34]. Fig.…”