| Title |
Electrochemical Hydrogenation Behavior of Surface-Treated Mg-based Alloys for Hydrogen Storage of Fuel Cell |
| Authors |
Ho-Sung Kim ; Jong-Ho Lee ; Seong-Jae Boo |
| Keywords |
Ni-MH battery ; Mg₂Ni based ; Hydrogen Storage Alloy ; Single Spherical Particle ; Microelectrode |
| Abstract |
The effects of surface treatment on the hydrogen storage properties of a Mg₂Ni alloy particle were investigated by the microvoltammetric technique, in which a carbon-filament microelectrode was manipulated to make electrical contact with the particle in a KOH aqueous solution. It was found that the hydrogen storage properties of Mg₂Ni at room temperature were improved by the surface treatment with a nickel plating solution. The sodium salts(sodium phosphate and sodium dihydrogen citrate) contained in the nickel plating solution made the alloy form an amorphous-like state, resulting in an improved hydrogen charge/discharge capacity at room temperature as high as about 150[mAh/g] from the original value of 17[mAh/g]. Potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom (Dapp) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. Dapp was found to vary the order between 10??[㎠/s]～10??[㎠/s] over the course of hydrogenation and dehydrogenation process. |