Microwave Construction of NiSb/NiTe Composites on Ni-Foam for High-Performance Supercapacitors
Ontology highlight
ABSTRACT:
SUBMITTER:
PROVIDER: S-EPMC10795113 | biostudies-literature | 2023 Dec
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:A novel MnO2/graphene/Ni foam electrode was fabricated via the impregnation and electrochemical deposition technique with Ni foams serving as substrates and graphene serving as a buffer layer for the enhanced conductivity of MnO2. The samples were characterized using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Compared with other methods, our strategy avoids using surfactants and high-temperature treatments. The electrodes exhibited excellent electrochemical performance, high capabilities, and a long cycle life. Various electrochemical properties were systematically studied using cyclic voltammetry and electrochemical impedance spectroscopy. The results showed that the specific capacitance of the MnO2/graphene/Ni composite prepared at 1 mA cm-2 of electrodeposition could achieve a scan rate of 10 mV s-1 at 292.8 F g-1, which confirmed that the graphene layer could remarkably improve electron transfer at the electrolyte-electrode interface. The capacitance retention was about 90% after 5000 cycles. Additionally, a MnO2/graphene//graphene asymmetric supercapacitor was assembled and it exhibited a high-energy density of 91 Wh kg-1 as well as had an excellent power density of 400 W kg-1 at 1 A g-1. It is speculated that the strong adhesion between the graphene and MnO2 can provide a compact structure to enhance the mechanical stability, which can be applied as a new method for energy storage devices.
| S-EPMC8537046 | biostudies-literature
Project description:Well-aligned nickel oxide (NiO) nanosheets with the thickness of a few nanometers supported on a flexible substrate (Ni foam) have been fabricated by a hydrothermal approach together with a post-annealing treatment. The three-dimensional NiO nanosheets were further used as electrode materials to fabricate supercapacitors, with high specific capacitance of 943.5, 791.2, 613.5, 480, and 457.5 F g(-1) at current densities of 5, 10, 15, 20, and 25 A g(-1), respectively. The NiO nanosheets combined well with the substrate. When the electrode material was bended, it can still retain 91.1% of the initial capacitance after 1,200 charging/discharging cycles. Compared with Co3O4 and NiO nanostructures, the specific capacitance of NiO nanosheets is much better. These characteristics suggest that NiO nanosheet electrodes are promising for energy storage application with high power demands.
| S-EPMC4177676 | biostudies-literature
Project description:The application of transition metal oxides/hydroxides in energy storage has long been studied by researchers. In this paper, the core-shell CNFs@Ni(OH)2/NiO composite electrodes were prepared by calcining carbon nanofibers (CNFs) coated with Ni(OH)2 under an N2 atmosphere, in which NiO was generated by the thermal decomposition of Ni(OH)2. After low-temperature carbonization at 200 °C, 250 °C and 300 °C for 1 h, Ni(OH)2 or/and NiO existed on the surface of CNFs to form the core-shell composite CNFs@Ni(OH)2/NiO-X (X = 200, 250, 300), in which CNFs@Ni(OH)2/NiO-250 had the optimal electrochemical properties due to the coexistence of Ni(OH)2 and NiO. Its specific capacitance could reach 695 F g-1 at 1 A g-1, and it still had 74% capacitance retention and 88% coulomb efficiency after 2000 cycles at 5 A g-1. Additionally, the asymmetric supercapacitor (ASC) assembled from CNFs@Ni(OH)2/NiO-250 had excellent energy storage performance with a maximum power density of 4000 W kg-1 and a maximum functional capacity density of 16.56 Wh kg-1.
| S-EPMC9738488 | biostudies-literature
Project description:As typical electrode materials for supercapacitors, low specific capacitance and insufficient cycling stability of transition metal oxides (TMOs) are still the problems that need to be solved. Design of core-shell structure is considered as an effective method for preparation of high-performance electrode materials. In this work, NiO flakes@CoMoO4 nanosheets/Ni foam (NiO flakes@CoMoO4 NSs/NF) core-shell architecture was constructed by a two-step hydrothermal method. Interestingly, the CoMoO4 NSs are vertically grown on the surface of NiO flakes, forming a two-dimensional (2D) branched core-shell structure. The porous core-shell architecture has relatively high surface area, effective ions channels, and abundant redox sites, resulting in excellent electrochemical performance. As a positive electrode for supercapacitors, NiO flakes@CoMoO4 NSs/NF core-shell architecture exhibits excellent capacitive performance in terms of high specific capacitance (1097 F/g at 1 A/g) and outstanding cycling stability (97.5% after 2000 circles). The assembled asymmetric supercapacitor (ASC) of NiO flakes@CoMoO4 NSs/NF//active carbon (AC)/NF possesses a maximum energy density of 25.8 Wh/kg at power density of 894.7 W/kg. The results demonstrate that NiO flakes@CoMoO4 NSs/NF electrode displays potential applications in supercapacitors and the design of 2D branched core-shell architecture paves an ideal way to obtain high-performance TMOs electrodes.
| S-EPMC6606686 | biostudies-literature
Project description:Mixed metal sulfides exhibit outstanding electrochemical performance compared to single metal sulfides and mixed metal oxides because of their richer redox reactions and high electronic conductivity. In the present study, Zn-Co-S nanostrip cluster arrays were formed from ZnCo2O4 grown on Ni foam by an anion exchange reaction using a two-step hydrothermal process. Morphological characterization confirmed that the Zn-Co-S nanostrip cluster arrays had grown homogeneously on the skeleton of the 3D Ni foam. The length of the nanostrip was approximately 8 µm, and the width ranged from 600 to 800 nm. The Ni foam-supported Zn-Co-S nanostrip cluster arrays were assessed directly for electrochemical supercapacitor applications. Compared to ZnCo2O4, the Zn-Co-S electrode exhibited a three-fold higher specific capacity of 830 C g-1 at a specific current of 2.0 A g-1. The higher polarizability, lower electro-negativity, and larger size of the S2- ion played an important role in substituting oxygen with sulfur, which enhanced the performance. The Zn-Co-S//AC hybrid device delivered a maximum specific energy of 19.0 Wh kg-1 at a specific power of 514 W kg-1. The remarkable performance of Zn-Co-S nanostrip cluster arrays highlights their potential as a positive electrode for hybrid supercapacitor applications.
| S-EPMC8706522 | biostudies-literature
Project description:A facile one-step hydrothermal reaction was employed to synthesis an integrated bifunctional composite composed by a network structure of ZnS/ZnO/Ni(OH)2 nanosheets with ZnS/ZnO nanospheres in situ growing on Ni foam. The synergistic effect of these three substances make the composite having both improved electrochemical performances and photocatalytic activity. The ZnS/ZnO/Ni(OH)2-4mmol shows a high specific capacitance of 1173.8 F g-1 at 1 A g-1, as well as good rate capability and relatively stable cyclability. Using as photocatalyst, the methyl orange dye in solution can be completely decomposed under ultraviolet-visible radiation in about 80 min. And the composite is easy to be repeatedly used because bulk Ni foam was used as a carrier. Such a bifunctional composite material provides a new insight for energy storage and utilization as well as the water pollution treatment.
| S-EPMC5465224 | biostudies-literature
Project description:Transition metal oxide aerogels are a fascinating class of compounds that have received considerable attention in the last decade owing to their unique and exceptional properties, including high porosity, large surface area, and ultralow density. In this study, α-Ni(OH)2 aerogels and annealed NiO/Ni aerogels were used to design and fabricate a two-electrode supercapacitor device. The physicochemical properties of the as-synthesized aerogels were characterized through X-ray diffraction, scanning electron microscopy, transmission electron microscopy, the Brunauer-Emmett-Teller theory, and X-ray photoelectron spectroscopy studies. The annealed NiO/Ni aerogels showed a (specific capacitance of 1060 F/g) specific capacity of 422 C/g at 1 A/g current density and with good cycling stability (up to 10,000 cycles). The supercapacitor also demonstrated an energy density of 32.4 Wh/kg and power density of 1800 W/kg at a current density of 2 A/g. The specific capacitance of NiO/Ni aerogels was more than twice that of the α-Ni(OH)2 aerogels. The practical applications of the aerogel were demonstrated by fabricating a two-electrode device.
| S-EPMC9655204 | biostudies-literature
Project description: Not available
| S-EPMC11243357 | biostudies-literature
Project description:Electrode materials are crucial for the electrochemical performance of supercapacitors. In view of the high specific surface area, high conductivity of graphene nanosheets and the high pseudocapacitance of polyaniline (PANI), the combination of graphene with PANI has become a research hotspot. In this work, we summarize the recent advance on the synthesis of PANI and graphene/PANI composites, and their application in supercapacitors. The synthesis of PANI is the basis of preparing graphene/PANI composites, so we first introduce the synthesis methods of PANI. Then, the advances of two dimensional (2D) and three dimensional (3D) graphene/PANI composites are summarized according to the inherent feature of graphene. The 2D composites of pristine graphene and functionalized graphene with PANI are introduced separately; furthermore, the 3D composites are classified into three sections, including flexible graphene/PANI composites, graphene framework based composites, and printable graphene/PANI composites. At last, aiming at solving the current challenges of graphene/PANI composites, we put forward some strategies for preparing high performance graphene/PANI composite electrodes.
| S-EPMC6540261 | biostudies-literature
Project description:Graphene oxide (GO) was rarely used as microwave absorption (MA) material due to its lower dielectric loss compared with reduced GO (RGO). However, the characteristics of low conductivity, light weight, and large surface area were beneficial to the impedance matching for absorbers already containing highly conductive metal materials. Cu@Ni nanowires are promising MA materials due to the desired dielectric loss from copper and excellent magnetic loss from nickel. However, the high density was an impediment to its further application. Combining Cu@Ni nanowires with GO should be an effective solution to decrease the absorber's density and improve its MA properties. Herein, we demonstrated that Cu@Ni nanowires/GO composites exhibited enhanced MA capacities compared with Cu@Ni nanowires or GO alone, and the minimum reflection loss reached -42.8 dB at 16.9 GHz with a thickness of 2.1 mm. The enhanced MA performance mainly originated from good impedance matching, as a result of the addition of low conductivity of GO. To confirm this point, the MA performance of Cu@Ni nanowires/RGO was studied, and unsurprisingly, weak MA performance was obtained. Our work provides a new strategy to decrease the density, broaden the frequency band and tune MA performance of composites.
| S-EPMC5431521 | biostudies-literature