Chemically grown 3D copper hydroxide electrodes with different morphologies for high-performance asymmetric supercapacitors

Present study investigated decoration of Cu(OH)(2) with different morphologies by copper precursors, on 3D nickel foam. The Cu(OH)(2)-A (nano flower)electrode showed an excellent capacitance of 1332 Fg(-1) at current density of 2 A g(-1) compared to the Cu(OH)(2)-C (nano ribbon, 1100 F g(-1)) and Cu(OH)(2)-S (nano long leaf, 1013 F g(-1)) electrodes. Asymmetric supercapacitor (ASC) was fabricated, and showed maximum capacitance of 165 Fg(-1) at current density of 2 A g(-1) with high energy density of 66.7 Wh kg(-1) and power density of 5698 W kg(-1) with excellent stability of 80% after 10,000 cycles. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved

Highly Uniform Atomic Layer-Deposited MoS2@3D-Ni-Foam: A Novel Approach To Prepare an Electrode for Supercapacitors

This article takes an effort to establish the potential of atomic layer deposition (ALD) technique toward the field of supercapacitors by preparing molybdenum disulfide (MoS2) as its electrode. 'While molybdenum hexacarbonyl [Mo(CO)(6)] serves as a novel precursor toward the low temperature 'synthesis of ALD-grown MoS2, H2S plasma helps to deposit its polycrystalline phase at 200 degrees C. Several ex situ characterizations such as X-ray diffractometry (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and so forth are performed in detail to study the as-grown MoS2 film on a Si/SiO2 substrate. While stoichiometric MoS2 with very negligible amount of C and O impurities was evident from XPS, the XRD and high-resolution transmission electron microscopy analyses confirmed the (002)-oriented polycrystalline h-MoS2 phase of the as-grown film. A comparative study of ALD-grown MoS2 as a supercapacitor electrode on 2-dimensional stainless steel and on 3-dimensional (3D) Ni-foam substrates clearly reflects the advantage and the potential of ALD for growing a uniform and conformal electrode material on a 3D-scaffold layer. Cyclic voltammetry measurements showed both double-layer capacitance and capacitance contributed by the faradic reaction at the MoS2 electrode surface. The optimum number of ALD cycles was also found out for achieving maximum capacitance for such a MoS2@3D-Ni-foam electrode. A record high areal capacitance of 3400 mF/cm(2) was achieved for MoS2@3D-Ni-foam grown by 400 ALD cycles at a current density of 3 mA/cm(2). Moreover, the ALD-grown MoS2@3D-Ni-foam composite also retains high areal capacitance, even up to a high current density of 50 mA/cm(2). Finally, this directly grown MoS2 electrode on 3D-Ni-foam by ALD shows high cyclic stability (>80%) over 4500 charge discharge cycles which must invoke the research community to further explore the potential of ALD for such applications

Clarifying the Role of Ordered Mesoporous Carbon on a Separator for High-Performance Lithium–Sulfur Batteries

Despite the remarkably high theoretical energy density (∼2600 W h kg–1), lithium–sulfur (Li–S) batteries are still far from commercialization due to the poor intrinsic electrical conductivity of sulfur and the polysulfide shuttle effect. In order to resolve these problems, various sulfur host materials and modified separators have been investigated. Herein, we investigate a dual-functional interlayer by applying ordered mesoporous carbon (OMC) on a commercial separator as (1) OMC provides sufficient capability for adsorbing dissolved polysulfide and (2) the OMC interlayer acts as an additional current collector (reaction site). An innovative investigation of the behaviors of adsorbed sulfur species in the OMC interlayer during cycling is conducted by operando small-angle X-ray scattering and energy-dispersive X-ray spectroscopy analysis. The Li–S cell with a particular configuration, which has only Ketjenblack (KB) without sulfur on the cathode and the OMC interlayer containing 70 wt % of sulfur on the separator, proves that the OMC interlayer provides an additional reaction site. The comprehensive analyses suggest that the dual-functionalized OMC interlayer exhibits great potential for fabricating high-performance Li–S batteries. In addition, the OMC interlayer results in improved electrochemical performances for a high-sulfur-loading cathode (90 wt % S/KB)

Molybdenum chalcogenides for supercapacitor applications : a critical review

The growing energy demands of daily life necessitate innovative solutions. Green approaches, which are universally accepted, advocate the use of renewable energy sources in conversion and storage systems. Research in nanomaterials has continually advanced, with the structures and shapes of these materials diversifying for a broad spectrum of applications. Supercapacitor-based systems are emerging as leading alternatives in contemporary trends among the various energy storage devices. In particular, transition metal dichalcogenides (TMDCs) are surfacing as novel supercapacitive electrode materials, thanks to ongoing research efforts. This review focuses on the technological development, characteristics, and properties of various transition metal chalcogenides used for supercapacitors. Mainly, molybdenum chalcogenides have been observed to be an emerging member of the TMDCs family that recently gained considerable attention for supercapacitor applications. This study briefly describes different synthesis methods and their parameters for molybdenum chalcogenide nanomaterials. The electrochemical properties like electrochemical impedance spectroscopy (EIS), specific capacitance (SC), cycling stability, energy density, and the power density of molybdenum chalcogenide-based supercapacitors have been discussed thoroughly with appropriate literature support