다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

In this critical review, metal oxides-based materials for electrochemical supercapacitor (ES) electrodes are reviewed in detail together with a brief review of carbon materials and conducting polymers. Their advantages, disadvantages, and performance in ES electrodes are discussed through extensive analysis of the literature, and new trends in material development are also reviewed. Two important future research directions are indicated and summarized, based on results published in the literature: the development of composite and nanostructured ES materials to overcome the major challenge posed by the low energy density of ES (476 references).

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A review of electrode materials for electrochemical supercapacitors

Nanocrystals are fundamental to modern science and technology. Mastery over the shape of a nanocrystal enables control of its properties and enhancement of its usefulness for a given application. Our aim is to present a comprehensive review of current research activities that center on the shape-controlled synthesis of metal nanocrystals. We begin with a brief introduction to nucleation and growth within the context of metal nanocrystal synthesis, followed by a discussion of the possible shapes that a metal nanocrystal might take under different conditions. We then focus on a variety of experimental parameters that have been explored to manipulate the nucleation and growth of metal nanocrystals in solution-phase syntheses in an effort to generate specific shapes. We then elaborate on these approaches by selecting examples in which there is already reasonable understanding for the observed shape control or at least the protocols have proven to be reproducible and controllable. Finally, we highlight a number of applications that have been enabled and/or enhanced by the shape-controlled synthesis of metal nanocrystals. We conclude this article with personal perspectives on the directions toward which future research in this field might take.

Shape‐Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics?

Graphene’s success has shown that it is possible to create stable, single and few-atom-thick layers of van der Waals materials, and also that these materials can exhibit fascinating and technologically useful properties. Here we review the state-of-the-art of 2D materials beyond graphene. Initially, we will outline the different chemical classes of 2D materials and discuss the various strategies to prepare single-layer, few-layer, and multilayer assembly materials in solution, on substrates, and on the wafer scale. Additionally, we present an experimental guide for identifying and characterizing single-layer-thick materials, as well as outlining emerging techniques that yield both local and global information. We describe the differences that occur in the electronic structure between the bulk and the single layer and discuss various methods of tuning their electronic properties by manipulating the surface. Finally, we highlight the properties and advantages of single-, few-, and many-layer 2D materials in...

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Progress, Challenges, and Opportunities in Two-Dimensional Materials Beyond Graphene

Rechargeable lithium-sulfur batteries.

An effective method for preparing uniform carbon coated nano-sized LiFePO4 particles

Microwave-irradiation synthesis of Li1.3NixCoyMn1―x―yO2.4 cathode materials for lithium ion batteries

The invention provides a method for improving graphene and copper basal body binding force in a copper-based graphene composite material; and the method prepares the composite material by a spark plasma sintering technology through adding a small amount of alloy elements in a copper basal body and mixing the alloy elements with graphene. Experiments prove that the method improves the interface binding force of the basal body and a graphene reinforcement phase in the composite material; and compared with a composite material prepared by adding no alloy element, high tensile resistance is achieved. In addition, the copper-based graphene composite material with excellent heat conductivity, electricity conductivity and wear resistance can be obtained by optimizing the adding quantity of the alloy elements and the mass of the graphene, so that excellent application prospect is achieved.

Method for improving graphene and copper basal body binding force in copper-based graphene composite material

Vanadium hexacyanoferrate (VHCF) with an open-framework crystal structure is a promising cathode material for rechargeable aqueous metal-ion batteries owing to its high electrochemical performance and easy synthesis. In this paper, vanadium hexacyanoferrate cathodes were first used for constructing rechargeable aqueous sodium-ion batteries (VHCF/WO3) and tested in the new-type electrolyte (NaP-4.6) consisting of a polyethylene glycol (PEG)/H2O/NaClO4 electrolyte with a low H+ concentration (molar ratio of [H2O]/[Na+] is 4.6), which has high stability at a high current density as high as 1000 mA g-1 with a capacity retention of 90.3% after 2000 cycles at high coulombic efficiency (above 97.8%). To understand their outstanding performance, the proton-assisted sodium-ion storage mechanism and interphase chemistry of VHCF are investigated by solid-state NMR (ssNMR) technology. It is suggested that the H+ storage reaction is accompanied by the redox of vanadium atoms and Na+ intercalation is accompanied by the redox of iron atoms. It is also observed that the complex of polyethylene glycol (PEG) with Na+ (PEG-Na+) exists on the VHCF surface, which facilitates the stability of VHCF and promotes the alkali-ion transfer at a high current density. The results of the ssNMR study offer new insights into the intercalation chemistry of Prussian blue analogues with open-framework-structured compounds, which can greatly broaden our horizons for battery research.

Zhaoping Liu

Papers

An effective method for preparing uniform carbon coated nano-sized LiFePO4 particles

Microwave-irradiation synthesis of Li1.3NixCoyMn1―x―yO2.4 cathode materials for lithium ion batteries

Method for improving graphene and copper basal body binding force in copper-based graphene composite material

Polyethylene Glycol–Na+ Interface of Vanadium Hexacyanoferrate Cathode for Highly Stable Rechargeable Aqueous Sodium-Ion Battery

La0.7(Sr0.3-xPdx)MnO3 as a highly efficient electrocatalyst for oxygen reduction reaction in aluminum air battery