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[Display omitted] • The polyhedral-shaped CdS decorated ZIF-8 nanocomposites have been prepared by in-situ synthesis. • It exhibits good cyclic stability, with 85.91 % (RAE) capacity retention after 6000 cycles at 5 A/g. • CdS@ZIF-8 achieves a specific capacitance of 1065 Fg−1 at 5 mV/s. With reference to the promising characteristics of metal–organic frameworks (MOFs) and the contributions of nanoparticles (NPs) to their electrochemical activities, the hybrid MOF built with metal sulphides has garnered a lot of attention, primarily as electrode materials in energy storage devices. The polyhedral-shaped CdS enwrapped zeolitic imidazolate framework-8 (ZIF-8) nanocomposites have been prepared by in-situ chemical synthesis. The electrochemical performance was evaluated in 6 M KOH electrolyte, achieving a specific capacitance of 1063.48 Fg−1 at 5 mV/s. The nanocomposite electrode material exhibits good cyclic stability, with 82.32 % (6 M KOH) and 85.91 % (redox additive electrolyte) capacity retention after 6000 cycles at 5 A/g. The energy and power density of the asymmetric supercapacitor were found to be 2.81 Wh/kg and 1785.71 W/kg, respectively. [ABSTRACT FROM AUTHOR]

Highlights • Hybrid WO 3 –V 2 O 5 nanocomposites were prepared. • Supercapacitor performance was analysed in two electrolytes such as KOH and H 2 SO 4. • The capacitance was enhanced in KOH electrolyte from 44 F/g to 173 F/g. • The capacitance was declined from 246 F/g to 12 F/g in the H 2 SO 4 electrolyte. • WO 3 –V 2 O 5 composites showed capacitance retention of ∼126% up to 5000 cycles. Abstract The rod shape WO 3 –V 2 O 5 hybrid nanocomposites were prepared by microwave assisted wet chemical route. The electrochemical investigations of as-prepared composites were carried in two electrolytes such as KOH and H 2 SO 4 for comparison. Their maximum capacitance was calculated as 44 F/g for WO 3 and 173 F/g for WO 3 –V 2 O 5 composites in KOH electrolyte and its efficiency is 100% up to 5000 cycles and its capacitance retention is ∼126% in KOH electrolyte. In H 2 SO 4 electrolyte, the specific capacitance of WO 3 was recorded as 246 F/g and WO 3 –V 2 O 5 showed poor performance such as less than 12 F/g. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A novel MnO 2 /g-C 3 N 4 @PPy ternary nanocomposite was designed and fabricated. • The ternary nanocomposite exhibited highly enhanced supercapacitor performance. • The ternary nanocomposite possessed outstanding cyclic stability. Abstract In this work, a novel MnO 2 /g-C 3 N 4 @polypyrrole (PPy) ternary nanocomposite (NC) was fabricated by coupling the MnO 2 nanorods with the two-dimensional g-C 3 N 4 sheets and the conductive PPy. The MnO 2 /g-C 3 N 4 @PPy NC electrode exhibited a high specific capacitance of 274 F g−1 at a current density of 2 A g−1, which was 1.88 times than that of the MnO 2 @PPy NC electrode. The MnO 2 /g-C 3 N 4 @PPy NC electrode also possessed outstanding cyclic stability with 95% capacitance retention after 1000 cycles. The present strategy for fabricating ternary nanocomposite uses low-cost raw materials and simple preparation method, which provides an alternative route to optimize the SC performance of other pseudocapacitive oxides. [ABSTRACT FROM AUTHOR]

Highlights • The as-prepared Ni 3 S 2 /CNTs electrode showed an excellent specific capacitance. • It shows good cycle stability with capacitance retention of 91.5% after 2000 cycles. • There's no binder involved in this method. • The electrodeposition-and-ion exchange technique is suitable for mass production. Abstract We reported a facile and easily controllable electrodeposition-and-ion exchange technique for synthesis of Ni 3 S 2 /carbon nanotubes (CNTs) nanocomposites on the surface of Ni foam for supercapacitor applications. When tested as electrode for a supercapacitor, a large surface area of the Ni 3 S 2 /CNTs hybrid nanoarchitecture was proven and it showed an excellent specific capacitance of 1643 F/g at the current density of 1 A/g, and maintains 999 F/g at 20 A/g. The Ni 3 S 2 /CNTs electrode also displayed good cycle stability with capacitance retention of 91.5% after 2000 cycles in 3 M KOH electrolyte. Because of these outstanding properties, the Ni 3 S 2 /CNTs nanocomposites are becoming promising candidates for the high performance binder-free supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

Highlights • Carbon-coated copper sulfide nanocomposite prepared via two-step sulfidation. • Cu 7 S 4 /C nanocomposite is ∼100 nm in size. • Cu 7 S 4 /C electrode exhibits highest capacitance (321.9 F g−1) at 0.5 A g−1. Abstract Metal-organic framework (MOF)-derived carbon-coated metal sulfides are a popular research area for energy storage, owing to their highly reactive nature and universal electrochemical activity. A simple and efficient method for the preparation of carbon-coated copper sulfide via a calcining-hydrothermal process using an MOF template is presented in this paper. The transmission electron microscope (TEM) imaging indicates that the cobble-like Cu 7 S 4 nanopolyhedra are ∼100 nm in size, and are interconnected by amorphous carbon. Electrochemical analysis shows that the Cu 7 S 4 /C electrode possesses the highest capacitance, 321.9 F g−1 (80.5 mAh g−1 in capacity), at a current density of 0.5 A g−1, and achieves nearly 78.1% capacitance retention after 3000 cycles, suggesting its holds promise for application in battery-type electrode materials for supercapacitors. [ABSTRACT FROM AUTHOR]

Sphere-feature MoSe 2 has been synthesized by using a facile hydrothermal method. The electrochemical properties of the as-prepared materials have been investigated for supercapacitors. Electrochemical measurements show that MoSe 2 spheres exhibit a specific capacitance of 243 F/g at 0.5 A/g, and still kept 90.3% capacitance after 1000 cycles at 1 A/g, indicating MoSe 2 sphere could be a promising candidate for high-performance supercapacitor applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • NGO/NiWO 3 /PANI nanocomposite was prepared by Hydrothermal method. • Current density of NGO/NiWO 3 /PANI electrode is significantly increased. • Specific capacitance of NGO/NiWO 3 /PANI electrode is about ∼1380 F/g at 0.5 A/g. • NGO/NiWO 3 /PANI electrode material displays excellent cycling stability. Hybrid supercapacitors signify a potential candidate for highly stable energy storage devices because of their excellent power density, low cost, and inherent safety. Hydrothermal method was used to synthesize NGO (Nitrogen doped graphene oxide)/NiWO 3 (nickel tungstate)/PANI (polyaniline)) nanocomposite (NC). GCD analysis offers noticeable enhanced specific capacitance of 1380 F/g as compared to NiWO 3 (670 F/g) and displays the cycle stability for 10 000 cycles with 92.6 % retention of capacitance at the current density of 0.5 A/g, and also shows a high energy density of 47.8 W h kg−1. These obtainable outcomes propose that NGO/NiWO 3 /PANI can be considered an efficient electrode for highly stable supercapacitors. [ABSTRACT FROM AUTHOR]

Nano-scale Co(OH) 2 /NG (nano-graphene: NG) composites serving as the active materials of miniature supercapacitors are deposited on macroporous electrically conductive network (MECN). The Co(OH) 2 /NG composite in the channels largely contribute to the capacitance. The electrochemical properties are investigated by cyclic voltammetry (CV), galvanostatic charging-discharging, and electrochemical impedance spectroscopy (EIS) in a 2 M KOH solution. The Co(OH) 2 /NG composite exhibits a stable capacitance of 3.522 F/cm 2 (880.5 F/g) and retention ratio is 99% after 5000 cycles demonstrating the stability and durability. The Co(OH) 2 /NG/MECN can be scanned faster than Co(OH) 2 /MECN in CV because of the higher conductivity. [ABSTRACT FROM AUTHOR]

Supercapacitors have drawn intensive attention in recent years due to their high specific power, long cycle life, and ability to fully fill the need for capacitors and batteries of hybrid energy applications. Electrodes of nanomaterials have shown superior electrochemical properties in performing high-performance supercapacitors. This feature article describes our recent progress in designing on different nanostructure of birnessite-type of manganese oxide-based materials for these applications. In order to fully understand the potential of manganese oxide-based electrode nanomaterials, sketchy appreciation of these morphology ranging from different dimensions and material properties are carried out critically, which may serve as a guidance for further development of fabricating supercapacitor electrode. [ABSTRACT FROM AUTHOR]

A new and facile one-step method to synthesise graphene oxide/natural rubber latex (GO/NRL) nanocomposite was achieved using an electrochemical exfoliation method. In this method, the fabrication of GO/NRL nanocomposite occurs concurrently with GO production that is intermixed with NRL. This approach is a simple and innovative method that succeeded in producing nanocomposite with better conductivity. The samples were characterized using FESEM, HRTEM, FT-IR, UV–vis, micro-Raman spectroscopy, XRD, TGA, I–V and C – V measurements. The C – V analysis showed that the specific capacitance of the samples prepared via the one-step method was 103.7 F g −1 , much better than those produced via a two-step method (32.6 F g −1 ). These results were also consistent with the I–V analysis, in which a higher conductivity value was measured for the one-step method (7.12×10 −5 S cm −1 ) than for the two-step method (3.62×10 −7 S cm −1 ). In conclusion, the one-step method introduced for the fabrication of GO/NRL nanocomposite is a promising method for implementation in supercapacitor applications. [ABSTRACT FROM AUTHOR]

• Solvothermal synthesis was used to make MnO 2 /MWCNT nanocomposites. • MnO 2 /MWCNT nanocomposites were employed as a binder-free super capacitor electrode. • MnO 2 /MWCNT electrode has a high specific capacitance and a good rate capability. • MnO 2 /MWCNT electrode annealed at 500 °C has a high specific capacitance of 314F/g. • CV curves of the MnO 2 /MWCNT electrode retain rectangular shape at high scan rates. This study presents the findings of MnO 2 tailoring in MWCNT for supercapacitor applications. Using a solvothermal method, we developed the MnO 2 /MWCNT nanocomposites with high energy storage capacity. The XRD peaks revealed the hexagonal structure of graphite and the tetragonal structure of birnessite type MnO 2. TEM revealed that the MWCNT sidewalls were decorated with a huge number of high purity manganese nanoparticles. According to CV studies, the composite electrode's specific capacitance exceeds 314F/g. As per the researchers, the tailored MnO 2 /MWCNT nanocomposites should promote the best electrode material for supercapacitor applications. [ABSTRACT FROM AUTHOR]

Nanosheets composite consisting of β-Ni(OH) 2 and reduction graphene oxide (β-Ni(OH) 2 /RGO) was successfully synthesized by improved hydrothermal process as electrochemical capacitor materials. The β-Ni(OH) 2 /RGO composite was tested as positive electrode material in a KOH aqueous electrolyte. The results show that the sample exhibits a high specific capacitance of 1740.56 F/g at a charge and discharge current density of 2.5 A/g, and the specific capacitance of β-Ni(OH) 2 /RGO is as high as 1326 F/g, even if the current density increase to 50 A/g. What is more, it exhibits an excellent long cycle life along with 93.8% specific capacitance retained after 1000 charge/discharge cycles. This composite displays a great promise as electrode materials for supercapacitor. [ABSTRACT FROM AUTHOR]

Abstract: In this work, we developed a one-pot approach to fabricate CoFe2O4/FeOOH nanocomposites without any surfactant. By tailoring the urea concentration, flower-like nanostructures of CoFe2O4/FeOOH nanocomposites can be obtained. The electrochemical properties of the CoFe2O4/FeOOH electrodes were elucidated by cyclic voltammograms, galvanostatic charge/discharge tests and electrochemical impedance spectroscopy in 6M KOH electrolyte. Flower-like CoFe2O4/FeOOH exhibited a specific capacitance of 332.4Fg−1 at the current density of 0.5Ag−1, and excellent cycling stability (91.3% retention after 1000 cycles, 5Ag−1). These findings suggested that this facile synthetic strategy could be useful to design and synthesize hierarchical electrode nanocomposites with enhanced supercapacitive performance. [Copyright &y& Elsevier]

Abstract: Sn-doped Mn3O4/C nanocomposite was synthesized using Pluronics P123 (EO20PO70EO20) as both structure-directing agent and carbon source. The phase and morphology was characterized with X-ray diffraction (XRD), X-ray spectroscopy (EDS), Field-emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). The electrochemical performance of the sample was tested in 6M KOH A high specific capacitance of 216Fg−1 was achieved at current density of 5Ag−1, and 93% capacitance retention remained after 10,000 charge/discharge cycles. [Copyright &y& Elsevier]

• Novel metal oxide nanostructures of copper and iron on Philippine natural zeolite (PNZ) matrix were successfully fabricated. • Comprehensive characterization proved the incorporation of Cu and Fe oxides on PNZ. • Calcined Cu/ and Fe/PNZ samples have the potential to be electrodes for supercapacitors. Herein, we report the formation of novel metal oxide nanostructures of copper and iron on Philippine natural zeolite (PNZ) matrix and their application as an electrode for supercapacitors for the first time. Flake-like and aggregated protruding nanoarchitectures were generated after calcination process of Cu- and Fe-exchanged PNZ samples, respectively. The successful inclusion of Cu and Fe were verified through comprehensive characterizations such as SEM-EDX, XRF, XRD, FTIR and XPS analyses. XRD and XPS analyses confirmed the presence of metal oxides species on the PNZ matrix. Electrochemical characterizations revealed the pseudocapacitance behaviour of both samples. These results highlight the potential of metal oxide/PNZ composites as novel electrodes for energy storage devices. [ABSTRACT FROM AUTHOR]

Abstract: Co3O4@graphene nanocomposite (Co3O4@GE) was prepared by a facile hydrothermal route. X-ray diffraction and transmission electron microscope proved Co3O4 nanoparticles with an average size of 5.8nm were homogeneously dispersed on sonication-exfoliated graphene sheets. X-ray photoelectron spectra indicated a low oxidation degree of graphene in Co3O4@GE. Small amount of functional groups on graphene sheets not only worked as anchor sites for Co3O4 nanoparticles, but also kept the carbon framework with lower defect density. Electrochemical experiments on Co3O4@GE showed high specific capacitance of 415F/g at a large current density of 3A/g in 6M KOH electrolyte, which is valuable for practical application in supercapacitors. [Copyright &y& Elsevier]