Electrochemical and Optical Properties of Magnesium-Alloy Hydrides Reviewed
As potential hydrogen storage media, magnesium based hydrides have been systematically studied in order to improve reversibility, storage capacity, kinetics and thermodynamics. The present article deals with the electrochemical and optical properties of Mg alloy hydrides. Electrochemical hydrogenati...
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| Format: | Article |
| Language: | English |
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MDPI AG
2012-10-01
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| Series: | Crystals |
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| Online Access: | http://www.mdpi.com/2073-4352/2/4/1410 |
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| author | Thirugnasambandam G. Manivasagam Kamil Kiraz Peter H. L. Notten |
| author_facet | Thirugnasambandam G. Manivasagam Kamil Kiraz Peter H. L. Notten |
| author_sort | Thirugnasambandam G. Manivasagam |
| collection | DOAJ |
| description | As potential hydrogen storage media, magnesium based hydrides have been systematically studied in order to improve reversibility, storage capacity, kinetics and thermodynamics. The present article deals with the electrochemical and optical properties of Mg alloy hydrides. Electrochemical hydrogenation, compared to conventional gas phase hydrogen loading, provides precise control with only moderate reaction conditions. Interestingly, the alloy composition determines the crystallographic nature of the metal-hydride: a structural change is induced from rutile to fluorite at 80 at.% of Mg in Mg-TM alloy, with ensuing improved hydrogen mobility and storage capacity. So far, 6 wt.% (equivalent to 1600 mAh/g) of reversibly stored hydrogen in MgyTM(1-y)Hx (TM: Sc, Ti) has been reported. Thin film forms of these metal-hydrides reveal interesting electrochromic properties as a function of hydrogen content. Optical switching occurs during (de)hydrogenation between the reflective metal and the transparent metal hydride states. The chronological sequence of the optical improvements in optically active metal hydrides starts with the rare earth systems (YHx), followed by Mg rare earth alloy hydrides (MgyGd(1-y)Hx) and concludes with Mg transition metal hydrides (MgyTM(1-y)Hx). In-situ optical characterization of gradient thin films during (de)hydrogenation, denoted as hydrogenography, enables the monitoring of alloy composition gradients simultaneously. |
| first_indexed | 2024-04-11T20:39:35Z |
| format | Article |
| id | doaj.art-27f0b2ff31cb4b2b9b156dd9626b8f34 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-04-11T20:39:35Z |
| publishDate | 2012-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-27f0b2ff31cb4b2b9b156dd9626b8f342022-12-22T04:04:14ZengMDPI AGCrystals2073-43522012-10-01241410143310.3390/cryst2041410Electrochemical and Optical Properties of Magnesium-Alloy Hydrides ReviewedThirugnasambandam G. ManivasagamKamil KirazPeter H. L. NottenAs potential hydrogen storage media, magnesium based hydrides have been systematically studied in order to improve reversibility, storage capacity, kinetics and thermodynamics. The present article deals with the electrochemical and optical properties of Mg alloy hydrides. Electrochemical hydrogenation, compared to conventional gas phase hydrogen loading, provides precise control with only moderate reaction conditions. Interestingly, the alloy composition determines the crystallographic nature of the metal-hydride: a structural change is induced from rutile to fluorite at 80 at.% of Mg in Mg-TM alloy, with ensuing improved hydrogen mobility and storage capacity. So far, 6 wt.% (equivalent to 1600 mAh/g) of reversibly stored hydrogen in MgyTM(1-y)Hx (TM: Sc, Ti) has been reported. Thin film forms of these metal-hydrides reveal interesting electrochromic properties as a function of hydrogen content. Optical switching occurs during (de)hydrogenation between the reflective metal and the transparent metal hydride states. The chronological sequence of the optical improvements in optically active metal hydrides starts with the rare earth systems (YHx), followed by Mg rare earth alloy hydrides (MgyGd(1-y)Hx) and concludes with Mg transition metal hydrides (MgyTM(1-y)Hx). In-situ optical characterization of gradient thin films during (de)hydrogenation, denoted as hydrogenography, enables the monitoring of alloy composition gradients simultaneously.http://www.mdpi.com/2073-4352/2/4/1410hydrogen storagemagnesium hydrideswitchable mirrorsbulk powdersthin filmselectrochemical hydrogenationgas phase hydrogenation |
| spellingShingle | Thirugnasambandam G. Manivasagam Kamil Kiraz Peter H. L. Notten Electrochemical and Optical Properties of Magnesium-Alloy Hydrides Reviewed Crystals hydrogen storage magnesium hydride switchable mirrors bulk powders thin films electrochemical hydrogenation gas phase hydrogenation |
| title | Electrochemical and Optical Properties of Magnesium-Alloy Hydrides Reviewed |
| title_full | Electrochemical and Optical Properties of Magnesium-Alloy Hydrides Reviewed |
| title_fullStr | Electrochemical and Optical Properties of Magnesium-Alloy Hydrides Reviewed |
| title_full_unstemmed | Electrochemical and Optical Properties of Magnesium-Alloy Hydrides Reviewed |
| title_short | Electrochemical and Optical Properties of Magnesium-Alloy Hydrides Reviewed |
| title_sort | electrochemical and optical properties of magnesium alloy hydrides reviewed |
| topic | hydrogen storage magnesium hydride switchable mirrors bulk powders thin films electrochemical hydrogenation gas phase hydrogenation |
| url | http://www.mdpi.com/2073-4352/2/4/1410 |
| work_keys_str_mv | AT thirugnasambandamgmanivasagam electrochemicalandopticalpropertiesofmagnesiumalloyhydridesreviewed AT kamilkiraz electrochemicalandopticalpropertiesofmagnesiumalloyhydridesreviewed AT peterhlnotten electrochemicalandopticalpropertiesofmagnesiumalloyhydridesreviewed |