Synthesis and electrochemical properties of binary MgTi and ternary MgTiX (X = Ni, Si) hydrogen storage alloys
| Autor: | DL Dmitry Danilov, Peter H. L. Notten, Thirugnasambandam G. Manivasagam, Merve Iliksu |
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| Přispěvatelé: | Control Systems, Dynamics and Control for Electrified Automotive Systems |
| Rok vydání: | 2017 |
| Předmět: |
Electrochemical impedance
Nickel metal hydride batteries Materials science Inorganic chemistry Energy Engineering and Power Technology 02 engineering and technology Overpotential 010402 general chemistry Electrochemistry 01 natural sciences Hydrogen storage Reaction rate constant Metal hydrides SDG 7 - Affordable and Clean Energy Thin film Renewable Energy Sustainability and the Environment 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Dielectric spectroscopy Electrochemical hydrogen Fuel Technology Magnesium alloys Gravimetric analysis 0210 nano-technology Ternary operation SDG 7 – Betaalbare en schone energie |
| Zdroj: | International Journal of Hydrogen Energy, 42(37), 23404-23415. Elsevier |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2017.03.093 |
| Popis: | Mg-based hydrogen storage alloys are promising candidates for many hydrogen storage applications because of the high gravimetric hydrogen storage capacity and favourable (de)hydrogenation kinetics. In the present study we have investigated the synthesis and electrochemical hydrogen storage properties of metastable binary Mg yTi 1−y (y = 0.80–0.60) and ternary Mg 0.63Ti 0.27X 0.10 (X = Ni and Si) alloys. The preparation of crystalline, single-phase, materials has been accomplished by means of mechanical alloying under controlled atmospheric conditions. Electrodes made of ball-milled Mg 0.80Ti 0.20 powders show a reduced hydrogen storage capacity in comparison to thin films with the same composition. Interestingly, for a Ti content lower than 30 at.% the reversible storage capacity increases with increasing Ti content to reach a maximum at Mg 0.70Ti 0.30. The charge transfer coefficients (α) and the rate constants (K 1 and K 2) of the electrochemical (de)hydrogenation reaction have been obtained, using a theoretical model relating the equilibrium hydrogen pressure, electrochemically determined by Galvanostatic Intermittent Titration Technique (GITT), and the exchange current. The simulation results reveal improved values for Mg 0.65Ti 0.35 compared to those of Mg 0.80Ti 0.20. The addition of Ni even more positively affects the hydrogenation kinetics as is evident from the increase in exchange current and, consequently, the significant overpotential decrease. |
| Databáze: | OpenAIRE |
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