The preparation and electrochemical properties of 3D ordered nickel oxide/silicon microchannel plate (NiO/Si-MCP) array electrode materials for supercapacitors are studied. The Si-MCP fabricated by electrochemical etching is used as a 3D supporting structure for electrodes. The active NiO is synthesized by electroless plating of nickel on the surface of the Si-MCP followed by annealing under oxygen. The electrochemical properties of the NiO/Si-MCP nanocomposite electrode materials are studied using cyclic voltammetry (CV), chronopotentiometry, and electrochemical impedance spectroscopy (EIS) in a 2 M KOH solution. The results reveal typical electrochemical capacitive behavior in the potential range from −0.6 to 1.0 V. The specific capacitance of approximately 586.4 F g−1 decreases slightly with 4.8% loss after 500 cycles. The linear and symmetrical charge/discharge curves are measured by chronopotentiometry. The NiO/Si-MCP composite is a promising electrode material for integrated supercapacitors. 相似文献
Nickel oxide is a promising material for electrochemical energy storage devices due to its high specific surface area, rapid redox reactions, and short diffusion path in the solid electrode. It has been known that the loading of metallic elements into the NiO matrix enhances these superior properties. NiO material is electrochemically deposited on Ni foam, and then, Ag and Cu thin layers are coated on NiO by thermal evaporation. The produced NiO/Ni foam and AgCu:NiO/Ni foam electrodes are annealed at 400 °C for 1 h. Those are utilized as anode for high-performance energy storage electrode in an alkaline solution. The former has an energy density of 56.9 Wh kg?1 at 3155.5 W kg?1, while the latter has a high energy density of 107.6 Wh kg?1 at the corresponding power density of 2957.7 W kg?1. Although specific capacitance of the former decreases to 46.2% of its original capacitance at 10 A g?1 after 5000 cycles, the latter exhibits higher cycling stability with 71.0% retention after 5000 charge–discharge cycles owing to the loading of Ag and Cu into NiO matrix. Charge transfer resistance of NiO/Ni foam, which is inversely proportional to electroactive surface area, reduces from 19.4 to 0.28 Ω after the incorporation of Ag and Cu. Compared to NiO/Ni foam, AgCu:NiO/Ni foam with a higher electroactive surface area is more appropriate for charge accumulation. As mention above, the features of AgCu:NiO/Ni foam indicate that it is a promising material as an effective start-of-art energy storage device.
Nickel oxide nanosheets have been successfully synthesized on the graphene foam (GF) using hydrothermal reflux process for their application as carbon monoxide (CO) gas sensor. X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, energy dispersive spectroscopy, and gas sorption analysis were used to characterize the structure and morphology of the samples. The morphology (SEM), crystal structure (XRD and Raman), and elemental composition (EDS) analysis of NiO/GF composite confirmed the cubic crystal structure of NiO and elemental composition (i.e., Ni, O, and C) of NiO/GF composite. The results reveal that the incorporation of graphene into NiO nanosheets not only improved the surface area of NiO/GF composite, but also enhanced the performance of the composite on CO sensing by improving its conductivity. These results indicate that NiO/GF has potential as electrode material for CO gas sensor. 相似文献
Nanostructured nickel-manganese oxides composite was prepared by the sol-gel and the chemistry deposition combination new route. The surface morphology and structure of the composite were characterized by scanning electron microscope and X-ray diffraction. The as-synthesized NiO/MnO2 samples exhibit higher surface area of 130-190 m2 g−1. Cyclic voltammetry and galvanostatic charge/discharge measurements were applied to investigate the electrochemical performance of the composite electrodes with different ratios of NiO/MnO2. When the mass ratio of MnO2 and NiO in composite material is 80:20, the specific capacitance value of NiO/MnO2 calculated from the cyclic voltammetry curves is 453 F g−1, for pure NiO and MnO2 are 209, 330 F g−1 in 6 mol L−1 KOH electrolyte and at scan rate of 10 mV s−1, respectively. The specific capacitance of NiO/MnO2 electrode is much larger than that of each pristine component. Moreover, the composite electrodes showed high power density and stable electrochemical properties. 相似文献
Cathodic electrodeposition method has been developed for the fabrication of Ag-doped MnO2 films from the KMnO4 aqueous solutions containing AgNO3 for the application in electrodes of electrochemical supercapacitors (ES). The films were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), cyclic voltammetry (CV) and impedance spectroscopy. The Ag-doped MnO2 films showed improved capacitive behaviour and lower electrical resistance compared to pure MnO2 films. The highest specific capacitance (SC) of 770 F g− 1 was obtained at a scan rate of 2 mV s− 1 in the 0.5 M Na2SO4 electrolyte. 相似文献
Journal of Materials Science: Materials in Electronics - High-surface-area Ni(OH)2-porous nitrogen-doped graphene (Ni(OH)2@p-NG) composite was electro-synthesized via a facile... 相似文献
The Mn1-xNixCo2O4 (0.00?≤?x?≤?0.20) nanoparticles were synthesized by a simple PAN-solution route. XRD, TEM, SAED, FESEM, XANES, XPS, and BET techniques were used to investigate the structural and morphology of Ni-doped MnCo2O4 nanoparticles. The effect of Ni ions substitution in MnCo2O4 nanoparticles on the electrochemical properties was examined on three-electrode systems. The results show that the substitution of Mn with Ni ions can improve the electrochemical properties of MnCo2O4 nanoparticles. The Mn1-xNixCo2O4 electrode with x?=?0.15 exhibits the highest specific capacitance of 378 F g?1 at the current density of 1 A g?1. After 1000 charge-discharges times, this electrode has good capacity retention of 85%. The good capacitance characteristics and cyclic stability indicate that these Mn1-0.85Ni0.15Co2O4 nanoparticles could be applied as active materials for energy storage devices.
Nitrogenated porous carbon materials, made by coating the pore surface with nitrogen functional groups from the pyrolysis of hexamine, were characterized and tested for supercapacitor applications. From X-ray photoelectron spectroscopy, the nitrogen content of the nitrogenated carbon sample was found to be 14?wt%. Electrochemical properties from potentiostatic and galvanostatic measurements, and open circuit voltage (OCV) were used to evaluate the effect of nitrogen in porous carbon electrodes. The nitrogenated carbon exhibits pseudocapacitive behavior and an increase in capacitance that is almost double that of plain porous carbon. The cyclic stability is also improved, as the sample retains its high capacitance even after extensive cycling. Also, the nitrogenated carbon shows battery-like characteristics with an initial OCV of ca. 0.4?V, and an OCV of ca. 0.3?V after cycling. 相似文献
Journal of Materials Science: Materials in Electronics - The development of new materials with complex structures has proved to be an effective approach to improve their capabilities in a variety... 相似文献
Journal of Materials Science: Materials in Electronics - Novel three-dimensional electrode materials with high capacitance, long cycle stability and electrocatalytic activity are designed through... 相似文献
Coordination polymers (CPs) and/or metal–organic frameworks (MOFs) are new active materials for supercapacitors (SC). In this study, by solvothermal route, we conduct the melamine-assisted synthesis of bimetallic CPs (Co–Ni CPs) with controllable structures. The concentration of melamine plays an important role in the morphology of Co–Ni CPs, and the CPs can be turned from microspheres to nanorods. The Co–Ni CPs are used as electrode materials for SC. The spherical Co–Ni–CP-M exhibits the highest capacitances of 677 F g?1 and 585 F g?1 at current densities of 1 A g?1 and 10 A g?1, respectively, indicating an outstanding rate capability in a three-electrode system with 2.0 M KOH electrolyte. Furthermore, the Co–Ni–CP-M//active carbon device shows superior long-term cycling stability, i.e., approximately 92.6% of the initial capacitance can be retained after 10,000 cycles at 10 A g?1 in 2.0 M KOH electrolyte. In addition, the asymmetric SC device achieves an excellent energy density of 28.35 W h kg?1 at a power density of 700 W kg?1.
In this article, three-dimensional (3D) heterostructured of MnO2/graphene/carbon nanotube (CNT) composites were synthesized by electrochemical deposition (ELD)-electrophoretic deposition (EPD) and subsequently chemical vapour deposition (CVD) methods. MnO2/graphene/CNT composites were directly used as binder-free electrodes to investigate the electrochemical performance. To design a novel electrode material with high specific area and excellent electrochemical property, the Ni foam was chosen as the substrate, which could provide a 3D skeleton extremely enhancing the specific surface area and limiting the huge volume change of the active materials. The experimental results indicated that the specific capacitance of MnO2/graphene/CNT composite was up to 377.1 F g?1 at the scan speed of 200 mV s?1 with a measured energy density of 75.4 Wh kg?1. The 3D hybrid structures also exhibited superior long cycling life with close to 90% specific capacitance retained after 500 cycles. 相似文献