scholarly journals Closed Bipolar Electrodes for Spatial Separation of H2 and O2 Evolution during Water Electrolysis and the Development of High-Voltage Fuel Cells

2017 ◽  
Vol 9 (28) ◽  
pp. 23654-23661 ◽  
Author(s):  
Sean Goodwin ◽  
Darren A. Walsh
Keyword(s):  
Fuel Cells ◽  
High Voltage ◽  
Water Electrolysis ◽  
Spatial Separation ◽  
O2 Evolution ◽  
Bipolar Electrodes

Applications of two dimensional material-MXene for proton exchange membrane fuel cells (PEMFCs) and water electrolysis

2020 ◽  
Vol 16 ◽  
Author(s):  
Chanchan Fan ◽  
Peng Zhang ◽  
Ranran Wang ◽  
Yezhu Xu ◽  
Xingrui Sun ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Water Splitting ◽  
Proton Exchange Membrane ◽  
Layer Structure ◽  
Metal Layer ◽  
Water Electrolysis ◽  
Proton Exchange ◽  
Two Dimensional ◽  
Max Phases ◽  
Early Transition Metal

: A new kind of two-dimensional (2D) materials MXene (early transition metal carbides, nitrides and carbonitrides) is obtained by selective etching the A element from the MAX phases. MXene exhibits both the metallic conductivity and the hydrophilic nature due to its metal layer structure and hydroxyl or oxygen terminated surfaces. This review provides an overview of the MXene used in the electrolytes and electrodes for the fuel cells and water splitting. MXene with functional groups termination could construct ion channels that significantly benefits to the ion conductivity through the electrolyte. The metal supported by MXene interaction offers electronic, compositional, and geometric effects that could enhance the catalytic activity and stability. MXene have already shown promising performance for fuel cells and water electrolysis. Herein, the etching and intercalation methods of MXene in recent years are summarized. The applications of MXene for fuel cells electrolyte, catalyst and water splitting catalyst are revealed to provide more brief idea for MXene used as new energy materials.

scholarly journals Development of an in-situ specimen holder for high-voltage environmental electron microscopy of fuel cells

2016 ◽  
pp. 225-226 ◽  
Author(s):  
Takafumi Ishida ◽  
Takayoshi Tanji ◽  
Masahiro Tomita ◽  
Kimitaka Higuchi ◽  
Koh Saitoh
Keyword(s):  
Electron Microscopy ◽  
Fuel Cells ◽  
High Voltage ◽  
Specimen Holder

Ventricular fibrillation threshold

1961 ◽  
Vol 201 (3) ◽  
pp. 457-461 ◽  
Author(s):  
Robert A. vanTyn ◽  
Lloyd D. MacLean
Keyword(s):  
Ventricular Fibrillation ◽  
Left Ventricle ◽  
Reliable Method ◽  
Spatial Separation ◽  
Bipolar Electrodes ◽  
Anatomical Position ◽  
Ventricular Fibrillation Threshold

The use of single rectangular stimuli, applied directly to the heart surface, has been confirmed as a reliable method for measurement of the ventricular fibrillation threshold (VFT). The following factors which influence reproducibility were investigated: 1) spatial separation of bipolar electrodes, 2) interval between stimuli, and 3) anatomical position of electrodes on the heart. With bipolar electrodes placed 10–30 mm apart and an interval of 10–15 cycles between stimuli the VFT was remarkably constant for any single dog. An interelectrode separation of 2–4 mm or the placement of electrodes in a coagulated area of epicardium produced high, widely variable, and at times unobtainable thresholds believed due to short circuiting of the current delivered. Thresholds determined with stimuli 3–4 beats apart were significantly lower than when stimuli were delivered 10–15 beats apart. The VFT was significantly higher at the base than at the apex of the left ventricle. Investigations which measure the effect of a given influence on the VFT should control the factors studied here.

Towards re-electrification of hydrogen obtained from the power-to-gas process by highly efficient H2/O2 polymer electrolyte fuel cells

RSC Advances ◽  
2014 ◽  
Vol 4 (99) ◽  
pp. 56139-56146 ◽  
Author(s):  
Felix N. Büchi ◽  
Marcel Hofer ◽  
Christian Peter ◽  
Urs D. Cabalzar ◽  
Jérôme Bernard ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Energy Storage ◽  
Electric Power ◽  
Polymer Electrolyte ◽  
Water Electrolysis ◽  
Polymer Electrolyte Fuel Cells ◽  
Pure Oxygen ◽  
Electrolysis Process ◽  
Highly Efficient ◽  
Power To Gas

In the power-to-gas process, hydrogen, produced by water electrolysis, is used for storage of excess renewable electric power. Pure oxygen is a byproduct of the electrolysis process. Using pure oxygen as the oxidant in polymer electrolyte fuel cells can increase the efficiency of the power-to-hydrogen-to-power energy storage chain.

An interleaved soft-switching converter with high voltage conversion ratio for fuel cells

2017 ◽  
Vol 104 (7) ◽  
pp. 1190-1213 ◽  
Author(s):  
Long-Yi Chang ◽  
Kuei-Hsiang Chao ◽  
Tsang-Chih Chang ◽  
Yang-Guang Liu ◽  
Liang-Chiao Huang
Keyword(s):  
Fuel Cells ◽  
High Voltage ◽  
Conversion Ratio ◽  
Soft Switching ◽  
Switching Converter ◽  
Voltage Conversion

scholarly journals High crystallinity design of Ir-based catalysts drives catalytic reversibility for water electrolysis and fuel cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Woong Hee Lee ◽  
Young-Jin Ko ◽  
Jung Hwan Kim ◽  
Chang Hyuck Choi ◽  
Keun Hwa Chae ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Catalytic Properties ◽  
Hydrogen Oxidation ◽  
Water Electrolysis ◽  
Oxidation Reactions ◽  
Hydrogen Electrode ◽  
Positive Potential ◽  
Nanoparticle Catalysts ◽  
High Crystallinity ◽  
Hydrogen Evolution Reactions

AbstractThe voltage reversal of water electrolyzers and fuel cells induces a large positive potential on the hydrogen electrodes, followed by severe system degradation. Applying a reversible multifunctional electrocatalyst to the hydrogen electrode is a practical solution. Ir exhibits excellent catalytic activity for hydrogen evolution reactions (HER), and hydrogen oxidation reactions (HOR), yet irreversibly converts to amorphous IrOx at potentials > 0.8 V/RHE, which is an excellent catalyst for oxygen evolution reactions (OER), yet a poor HER and HOR catalyst. Harnessing the multifunctional catalytic characteristics of Ir, here we design a unique Ir-based electrocatalyst with high crystallinity for OER, HER, and HOR. Under OER operation, the crystalline nanoparticle generates an atomically-thin IrOx layer, which reversibly transforms into a metallic Ir at more cathodic potentials, restoring high activity for HER and HOR. Our analysis reveals that a metallic Ir subsurface under thin IrOx layer can act as a catalytic substrate for the reduction of Ir ions, creating reversibility. Our work not only uncovers fundamental, uniquely reversible catalytic properties of nanoparticle catalysts, but also offers insights into nanocatalyst design.

Ultrathin Cu-MOF@δ-MnO2 nanosheets for aqueous electrolyte-based high-voltage electrochemical capacitors

2018 ◽  
Vol 6 (36) ◽  
pp. 17329-17336 ◽  
Author(s):  
Jing Xu ◽  
Yan Wang ◽  
Shuai Cao ◽  
Jian Zhang ◽  
Guangxun Zhang ◽  
...  
Keyword(s):  
High Voltage ◽  
Aqueous Electrolyte ◽  
Electrochemical Capacitors ◽  
Water Electrolysis ◽  
Operating Voltage ◽  
Asymmetric Supercapacitor ◽  
Mno2 Nanosheets

Ultrathin Cu-MOF@δ-MnO2 nanosheets have been successfully prepared and the operating voltage window of the asymmetric supercapacitor can reach high values in aqueous electrolyte without any water electrolysis.

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