Partial substitution of cobalt for nickel in mixed rare earth metal based superlattice hydrogen absorbing alloy – Part 1 structural, hydrogen storage and electrochemical properties
| Autor: | Tiejun Meng, Kwo-Hsiung Young, Taihei Ouchi, Shigekazu Yasuoka, Lixin Wang |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Hydrogen Superlattice Inorganic chemistry Alloy Analytical chemistry chemistry.chemical_element 02 engineering and technology engineering.material 010402 general chemistry 01 natural sciences Metal Condensed Matter::Materials Science Hydrogen storage Materials Chemistry Hydride Mechanical Engineering Metals and Alloys equipment and supplies 021001 nanoscience & nanotechnology 0104 chemical sciences Nickel chemistry Mechanics of Materials visual_art engineering visual_art.visual_art_medium 0210 nano-technology Cobalt |
| Zdroj: | Journal of Alloys and Compounds. 660:407-415 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2015.11.134 |
| Popis: | The structural, gaseous phase hydrogen storage and electrochemical properties of a series of cobalt-substituted superlattice alloys were investigated as Part 1 of a two-part series. The phase abundances, lattice parameters and unit cell volumes of the AB 5 , AB 3 and A 2 B 7 phases were analyzed by X-ray diffraction patterns. Cobalt (Co) has a more noticeable effect on promoting the AB 5 phase than manganese (Mn) and increases both the gaseous phase hydrogen storage and electrochemical capacity of the alloys. It does this by forming more stable hydrides with a lower pressure-concentration-temperature plateau pressure and a more negative heat of formation. The decreasing entropy difference also indicates that Co promotes a more ordered hydride. An alloy with 7 at% Co shows the best high-rate electrochemical performance due to the increased hydrogen diffusion coefficient and exchange current density. Magnetic susceptibility measurements indicate that there are other factors besides the surface nickel (Ni) cluster that dominate the high-rate performance of the Co-substituted superlattice alloys. |
| Databáze: | OpenAIRE |
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