Surface Passivation Of Metal Hydrides For Applications

1998 ◽  
Vol 513 ◽  
Author(s):  
S. Suda ◽  
Z. -P. Li ◽  
Y.-M. Sun ◽  
B.-H. Liu ◽  
X.-P. Gao
Keyword(s):  
Electrolyte Solution ◽  
Atomic Hydrogen ◽  
Surface Passivation ◽  
Metal Hydrides ◽  
Electrochemical Reactions ◽  
Body Centered Cubic ◽  
Alloy Particles ◽  
Charge Discharge ◽  
Improved Characteristics

ABSTRACTProperties and characteristics of hydriding alloys are strongly dependent on surface compositions and morphologies. For instance, oxides such as La203 on AB5 alloys and ZrO2 on AB2, AB, and body-centered-cubic (BCC) alloys act as the barriers for the conversion of molecular and ionic hydrogen to atomic hydrogen at the surface, thus reducing the kinetics in both the gas-solid and electrochemical reactions.Alloy surfaces chemically treated by an aqueous F-ion containing solution have been developed to solve such problems. F-treated surfaces exhibit significantly improved characteristics in regard to the hydrogen uptakes and the protection against impurities and electrolyte solution. In addition, highly conductive metallic Ni layers can be formed on the surface of the alloy particles by the fluorination.The authors report the properties and characteristics of fluorinated hydriding alloys, mainly of a typical AB2 Laves phase material which represents the difficult activation characteristics and poor long-term durability during electrochemical charge/discharge cycles.

scholarly journals Suppression of byproduct accumulation in rechargeable aluminum–air batteries using non-oxide ceramic materials as air cathode materials

2017 ◽  
Vol 1 (5) ◽  
pp. 1082-1089 ◽  
Author(s):  
Ryohei Mori
Keyword(s):  
Ionic Liquid ◽  
Cathode Materials ◽  
High Capacity ◽  
Ceramic Materials ◽  
Electrochemical Reactions ◽  
Oxide Ceramic ◽  
Air Cathode ◽  
Air Battery ◽  
Charge Discharge

To develop a high-capacity rechargeable aluminum–air battery with resistance toward the degradation induced by long-term charge–discharge electrochemical reactions, non-oxide ceramic materials, e.g., TiN, TiC, and TiB2, were used as air cathode materials with the ionic liquid 1-ethyl-3-methylimidazolium chloride as the electrolyte.

scholarly journals Electrochemical properties of a rechargeable aluminum–air battery with a metal–organic framework as air cathode material

RSC Advances ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 6389-6395 ◽  
Author(s):  
Ryohei Mori
Keyword(s):  
Cathode Material ◽  
Electrochemical Properties ◽  
Metal Organic Framework ◽  
High Capacity ◽  
Electrochemical Reactions ◽  
Air Cathode ◽  
Metal Organic ◽  
Air Battery ◽  
Charge Discharge

The goal of this study was to develop a rechargeable aluminum–air battery with high capacity and long-term durability in charge–discharge electrochemical reactions.

Performance and Long-Term Charge/Discharge Properties of a Capacitor Electrode of Carbon Gel in an Organic Electrolyte

2017 ◽  
Vol 43 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Hikaru Tsuchida ◽  
Zairan Cheng ◽  
Kiyoharu Nakagawa ◽  
Hirokazu Oda
Keyword(s):  
Organic Electrolyte ◽  
Carbon Gel ◽  
Charge Discharge

Long-Term Stability of Aluminum Oxide Based Surface Passivation Schemes Under Illumination at Elevated Temperatures

2017 ◽  
Vol 7 (5) ◽  
pp. 1197-1202 ◽  
Author(s):  
Tim Niewelt ◽  
Wolfram Kwapil ◽  
Marisa Selinger ◽  
Armin Richter ◽  
Martin C. Schubert
Keyword(s):  
Aluminum Oxide ◽  
Elevated Temperatures ◽  
Surface Passivation ◽  
Term Stability ◽  
Long Term Stability

scholarly journals Preparation of Porous Carbon Nanofibers with Tailored Porosity for Electrochemical Capacitor Electrodes

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 729 ◽  
Author(s):  
Jisu Kim ◽  
Youn-Ji Heo ◽  
Jin-Yong Hong ◽  
Sung-Kon Kim
Keyword(s):  
Silica Nanoparticles ◽  
Carbon Nanofibers ◽  
Porous Carbon ◽  
High Performance ◽  
Weight Ratio ◽  
Electrochemical Capacitor ◽  
Electrochemical Performances ◽  
Porous Carbon Electrodes ◽  
Charge Discharge

Porous carbon electrodes that accumulate charges at the electrode/electrolyte interface have been extensively investigated for use as electrochemical capacitor (EC) electrodes because of their great attributes for driving high-performance energy storage. Here, we report porous carbon nanofibers (p-CNFs) for EC electrodes made by the formation of a composite of monodisperse silica nanoparticles and polyacrylonitrile (PAN), oxidation/carbonization of the composite, and then silica etching. The pore features are controlled by changing the weight ratio of PAN to silica nanoparticles. The electrochemical performances of p-CNF as an electrode are estimated by measuring cyclic voltammetry and galvanostatic charge/discharge. Particularly, the p-CNF electrode shows exceptional areal capacitance (13 mF cm−2 at a current of 0.5 mA cm−2), good rate-retention capability (~98% retention of low-current capacitance), and long-term cycle stability for at least 5000 charge/discharge cycles. Based on the results, we believe that this electrode has potential for use as high-performance EC electrodes.

Mixed Mn3+/Mn4+ in high-voltage nano-structured lithium nickel manganese oxide cathode with a P4332 structure

2017 ◽  
Vol 10 (06) ◽  
pp. 1750074 ◽  
Author(s):  
Yu Li ◽  
Yi-Jie Gu ◽  
Yun-Bo Chen ◽  
Hong-Quan Liu ◽  
Yong-Qin Han ◽  
...  
Keyword(s):  
Oxygen Vacancies ◽  
Electrochemical Reactions ◽  
Discharge Process ◽  
Icp Oes ◽  
Space Group ◽  
Oxide Cathode ◽  
Co Precipitation ◽  
Nickel Manganese ◽  
Charge Discharge ◽  
Discharge Curves

In this paper, we have synthesized LiNi[Formula: see text]Mn[Formula: see text]O4 with P4332 space group by carbonate co-precipitation. TG/DSC, TG*, ICP-OES, a gas displacement pycnometer using He gas, XPS, and XRD refinement results show that oxygen vacancies exist in the LiNi[Formula: see text]Mn[Formula: see text]O[Formula: see text] with a P4332 space group. There is a mixture of Mn[Formula: see text] and Mn[Formula: see text] in the P4332 structured LiNi[Formula: see text]Mn[Formula: see text]O[Formula: see text]. Despite the large amount of Mn[Formula: see text] in the spinel structure, no 4.0[Formula: see text]V plateau appears in charge–discharge curves. This result indicates that the Mn[Formula: see text] in LiNi[Formula: see text]Mn[Formula: see text]O[Formula: see text] does not participate in electrochemical reactions during the charge–discharge process.

scholarly journals Hydroxyl layer: trend of number density and intra-annual variability

2015 ◽  
Vol 33 (6) ◽  
pp. 749-767 ◽  
Author(s):  
G. R. Sonnemann ◽  
P. Hartogh ◽  
U. Berger ◽  
M. Grygalashvyly
Keyword(s):  
Atomic Hydrogen ◽  
Middle Atmosphere ◽  
Transport Model ◽  
Anthropogenic Impacts ◽  
Number Density ◽  
Hemispheric Differences ◽  
Chemical Transport Model ◽  
Mesopause Region ◽  
Production Term

Abstract. The layer of vibrationally excited hydroxyl (OH*) near the mesopause in Earth's atmosphere is widely used to derive the temperature at this height and to observe dynamical processes such as gravity waves. The concentration of OH* is controlled by the product of atomic hydrogen, with ozone creating a layer of enhanced concentration in the mesopause region. However, the basic influences on the OH* layer are atomic oxygen and temperature. The long-term monitoring of this layer provides information on a changing atmosphere. It is important to know which proportion of a trend results from anthropogenic impacts on the atmosphere and which proportion reflects natural variations. In a previous paper (Grygalashvyly et al., 2014), the trend of the height of the layer and the trend in temperature were investigated particularly in midlatitudes on the basis of our coupled dynamic and chemical transport model LIMA (Leibniz Institute Middle Atmosphere). In this paper we consider the trend for the number density between the years 1961 and 2009 and analyze the reason of the trends on a global scale. Further, we consider intra-annual variations. Temperature and wind have the strongest impacts on the trend. Surprisingly, the increase in greenhouse gases (GHGs) has no clear influence on the chemistry of OH*. The main reason for this lies in the fact that, in the production term of OH*, if atomic hydrogen increases due to increasing humidity of the middle atmosphere by methane oxidation, ozone decreases. The maximum of the OH* layer is found in the mesopause region and is very variable. The mesopause region is a very intricate domain marked by changeable dynamics and strong gradients of all chemically active minor constituents determining the OH* chemistry. The OH* concentration responds, in part, very sensitively to small changes in these parameters. The cause for this behavior is given by nonlinear reactions of the photochemical system being a nonlinear enforced chemical oscillator driven by the diurnal-periodic solar insolation. At the height of the OH* layer the system operates in the vicinity of chemical resonance. The solar cycle is mirrored in the data, but the long-term behavior due to the trend in the Lyman-α radiation is very small. The number density shows distinct hemispheric differences. The calculated OH* values show sometimes a step around a certain year. We introduce a method to find out the date of this step and discuss a possible reason for such behavior.

Interpreting Abnormal Charge–Discharge Plateau Migration in CuxS during Long-Term Cycling

2019 ◽  
Vol 11 (4) ◽  
pp. 3961-3970 ◽  
Author(s):  
Zuguang Yang ◽  
Ting Chen ◽  
Chunjin Wu ◽  
Jie Qu ◽  
Zhenguo Wu ◽  
...  
Keyword(s):  
Charge Discharge
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