Qidong Wang

Bio: Qidong Wang is an academic researcher from Zhejiang University. The author has contributed to research in topics: Hydrogen storage & Hydrogen. The author has an hindex of 39, co-authored 195 publications receiving 5130 citations. Previous affiliations of Qidong Wang include Fudan University.

Advanced hydrogen storage alloys for Ni/MH rechargeable batteries

Abstract: Hydrogen storage alloys are of particular interest as a novel group in functional materials owing to their potential and practical applications in Ni/MH rechargeable batteries. This review is devoted to the specific alloy families developed for high-energy and high-power Ni/MH batteries in the last decades, especially for EV, HEV and PHEV applications. The scope of the work encompasses principles of Ni/MH batteries, electrochemical hydrogen storage thermodynamics and kinetics, prerequisites for hydrogen storage electrode alloys and recent advances in hydrogen storage electrode alloys. Rare earth AB5-type alloys, Ti- and Zr-based AB2-type alloys, Mg-based amorphous/nanocrystalline alloys, rare earth-Mg–Ni-based alloys and Ti–V-based alloys are highlighted. Additionally, the challenges met in developing advanced hydrogen storage alloys for Ni/MH rechargeable batteries are pointed out and some research directions are suggested.

Size-Dependent Kinetic Enhancement in Hydrogen Absorption and Desorption of the Li−Mg−N−H System

Abstract: High operating temperature and slow kinetics retard the practical applications of the Li-Mg-N-H system for hydrogen storage To alleviate these problems, a first attempt was carried out by synthesizing Li(2)MgN(2)H(2) through sintering a mixture of Mg(NH(2))(2)-2LiNH(2) and investigating its size-dependent hydrogen storage performance A dramatically enhanced kinetics for hydrogen absorption/desorption was achieved with a reduction in the particle size For the dehydrogenation reaction, a three-dimensional diffusion-controlled kinetic mechanism was identified for the first time by analyzing isothermal hydrogen desorption curves with a linear plot method The experimental improvement and mechanistic understanding on the dehydrogenation kinetics of the Li-Mg-N-H system shed light on how to further decrease the operating temperature and enhance the hydrogen absorption/desorption rate of the amide/hydride combined materials

A Study of the Structural and Electrochemical Properties of La0.7Mg0.3 ( Ni0.85Co0.15 ) x ( x = 2.5 ­ 5.0 ) Hydrogen Storage Alloys

Abstract: In this paper, the structural and electrochemical properties of La 0.7 Mg 0.3 (Ni 0.85 Co0.15) x (x = 2.5,3.0,3.5,4.0,4.5,5.0) hydrogen storage alloy electrodes were studied systematically. X-ray diffraction Rietveld analyses show that all these alloys consist of a (La, Mg)Ni 3 phase with the PuNi 3 -type rhombohedral structure and a LaNi 5 phase with the CaCu 5 -type hexagonal structure. The (La, Mg)Ni 3 phase abundance first increases to a high percentage (∼75%) and then decreases with increasing x. In contrast, the LaNi 5 -phase abundance first remains low and almost unchanged and then increases to a high percentage (∼70%) with increasing x. The pressure-composition isotherms shows that for each isotherm the plateau region widens and the plateau pressure is maintained almost unchanged when x increases from 2.5 to 3.5. However, as x increases further, the plateau region is shortened and becomes flatter, and the plateau pressure increases with x. Electrochemical studies indicate that all important electrochemical properties, including the maximum discharge capacity, the high rate dischargeability, the exchange current density, and the limiting current density of the alloy electrodes increase as x increases from 2.5 to 3.5 and then decrease when x increases further from 3.5 to 4.5.

Mechanical Alloying And Milling

Abstract: Mechanical alloying (MA) is a solid-state powder processng technique involving repeated welding, fracturing, and rewelding of powder particles in a high-energy ball mill. Originally developed to produce oxide-dispersion strengthened (ODS) nickel- and iron-base superalloys for applications in the aerospace industry, MA has now been shown to be capable of synthesizing a variety of equilibrium and non-equilibrium alloy phases starting from blended elemental or prealloyed powders. The non-equilibrium phases synthesized include supersaturated solid solutions, metastable crystalline and quasicrystalline phases, nanostructures, and amorphous alloys. Recent advances in these areas and also on disordering of ordered intermetallics and mechanochemical synthesis of materials have been critically reviewed after discussing the process and process variables involved in MA. The often vexing problem of powder contamination has been analyzed and methods have been suggested to avoid/minimize it. The present understanding of the modeling of the MA process has also been discussed. The present and potential applications of MA are described. Wherever possible, comparisons have been made on the product phases obtained by MA with those of rapid solidification processing, another non-equilibrium processing technique.

Complex Hydrides for Hydrogen Storage

Abstract: Note: Times Cited: 875 Reference EPFL-ARTICLE-206025doi:10.1021/cr0501846View record in Web of Science URL: ://WOS:000249839900009 Record created on 2015-03-03, modified on 2017-05-12