naming of energy storage devices after their own core materials: conventional batteries such as lead-acid batteries, which are named after the lead-based active material and the acidic electrolyte; nickelcadmium batteries named after the nickeland cadmium-based active materials; nickel-metal hybrid batteries named after the nickel-and metal hydride-based active materials; state-of-the-art lithium-ion batteries (LIBs), named after the lithiated host materials and lithium-ion carriers; and next-generation batteries such as sodiumion, lithium-sulfur, and lithium-air batteries, which are named after the lithium metal anode and sulfur or O 2 cathode. [4][5][6][7][8][9] In short, whenever energy storage materials made a breakthrough, new-generation energy storage devices appeared. Among electrochemical energy storage devices, supercapacitors (SCs), which can store charges at the surface, have advantages over LIB and conventional batteries in terms of high power, fast charging/ discharging rates, and long cyclability, as will be discussed in Section 2.1. However, the low energy density of SCs remains a critical challenge for emerging applications such as next-generation electronic systems, electrical vehicles (EVs), and renewable energy storage systems (ESSs). [10,11] Based on the long history of energy storage research, new and emerging materials are expected to provide solutions to this problem.Returning to the chronological development of SCs, SCs have been revolutionized by the emergence of new materials, as Two dimensional (2D) nanomaterials are very attractive due to their unique structural and surface features for energy storage applications. Motivated by the recent pioneering works demonstrating "the emergent pseudocapacitance of 2D nanomaterials," the energy storage and nanoscience communities could revisit bulk layered materials though state-of-the-art nanotechnology such as nanostructuring, nanoarchitecturing, and compositional control. However, no review has focused on the fundamentals, recent progress, and outlook on this new mechanism of 2D nanomaterials yet. In this study, the key aspects of emergent pseudocapacitors based on 2D nanomaterials are comprehensively reviewed, which covers the history, classification, thermodynamic and kinetic aspects, electrochemical characteristics, and design guidelines of materials for extrinsically surface redox and intercalation pseudocapacitors. The structural and compositional controls of graphene and other carbon nanosheets, transition metal oxides and hydroxides, transition metal dichalcogenides, and metal carbide/nitride on both microscopic and macroscopic levels will be particularly addressed, emphasizing the important results published since 2010. Finally, perspectives on the current impediments and future directions of this field are offered. Unlimited combinations and modifications of 2D nanomaterials can provide a rational strategy to overcome intrinsic limitations of existing materials, offering a new-generation energy storage materials toward a high and new p...

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Multiwall carbon nanotube (MWCNT) based nanocomposites were prepared by a two-step process. Firstly, titanium dioxide (TiO2) coated MWCNT was prepared via sol-gel technique. In the second step, the acid modified MWCNTs were dispersed in the thermoplastic polyurethane matrix by solution blending process. Characterizations of the nanocomposites were done by X-ray diffraction analysis, X-ray photoelectron spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy and Energy-dispersive X-ray spectroscopy. Microwave absorption studies of the nanocomposites were carried out in X-band region. The microwave absorption result was discussed with the help of complex permittivity and permeability of the prepared radar absorbing material (RAM). The result showed superior microwave absorption property of the composite containing both TiO2 coated MWCNT and magnetite (Fe3O4). This result is due to the effective absorption of both electrical and magnetic components of the microwave. RAM-MW, RAM-Ti, RAM-Ti@MW and RAMTi@ MW/Fe and showed the maximum reflection loss of –16.03 dB at 10.99 GHz, –8.4 dB at 12.4 GHz, –36.44 dB at 12.05 GHz and –42.53 dB at 10.98 GHz respectively. Incorporation of MWCNT enhanced the thermal stability of the composite which has been confirmed by thermogravimetric analysis

The reduction of the dislocation density in relaxed SiGe/Si heterostructures using a low-temperature Si͑LT-Si͒ buffer has been investigated. We have shown that a 0.1 m LT-Si buffer reduces the threading dislocation density in mismatched Si 0.85 Ge 0.15 /Si epitaxial layers as low as ϳ10 4 cm Ϫ2. Samples were grown by both gas-source molecular beam epitaxy and ultrahigh vacuum chemical vapor deposition.

The development of promising microwave absorbing materials is a booming field of research in both the commercial and defense sectors to prevent electromagnetic pollution, and also to enrich the field of stealth technology. Supercapacitors are a symbol of clean energy storage devices. The present work attends to the preparation of hexagonal shaped magnetic M-type hexaferrite, CuFe 10 Al 2 O 19 (CFA) by a facile chemical co-precipitation method, and the formation of its composites (graphene/CFA) in the presence of acid modified graphene. An in situ approach was employed for the coating of graphene with CFA. Another nanocomposite (graphene/CFA/PANI) was prepared by the wrapping of graphene/CFA with polyaniline (PANI), which was prepared through the in situ chemical oxidation polymerization of aniline.The prepared multifunctional nanocomposites showed an outstanding and improved microwave absorption property (the maximum reflection loss was À63.6 dB at a thickness of 2.5 mm with a broad absorption range) and electrochemical properties (the highest specific capacitance value was 342 F g À1 ), in contrast to the pristine graphene and CFA. The addition of PANI also improves the microwave absorption and specific capacitance of the nanocomposites. The formation of the multifunctional nanocomposites and their structural characteristics are discussed thoroughly with their impact on the two different fields of applications i.e. microwave absorbing and energy storage device applications individually.