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Graphene/silver nanocomposites stabilize Mg-Ni-La electrode alloys and enhance electrochemical performance.
- Source :
-
Journal of Alloys & Compounds . Feb2017, Vol. 694, p1140-1148. 9p. - Publication Year :
- 2017
-
Abstract
- The influence of a graphene/silver (G/A) nanocomposite coating layer on the microstructural evolution and surface oxidation of a Mg–Ni–La hydride is investigated systematically by XRD, SEM, EDS and HRTEM in detail. SEM and EDS reveal that the existence of the G/A composite prevents the electrode from pulverizing and oxidizing. The oxygen content in the surface of the electrode is reduced from 21% to 10% after 50 cycles for a Mg-Ni-La electrode with 0.2 mass fraction of G/A. The crystallization process of the amorphous electrodes coated by G/A is reduced compared to the uncoated electrode and the stable Mg 2 NiH 4 , α-Mg, MgH 2 and La oxihydroxide phases are present with the grain size about 40–60 nm after 50 charge/discharge cycles. The G/A coating reduces the corrosion and oxidation of the electrode alloy and provides both a pathway for hydrogen diffusion and active sites for the redox reaction of hydrogen. All of these factors result in a significant improvement of the discharge capacity by about 200 mAh g −1 in each cycle (after activation) for Mg-Ni-La electrodes with 0.2 mass fraction of G/A nanocomposites. [ABSTRACT FROM AUTHOR]
- Subjects :
- *GRAPHENE
*SILVER
*ELECTRODES
*NANOCOMPOSITE materials
*CRYSTALLIZATION
Subjects
Details
- Language :
- English
- ISSN :
- 09258388
- Volume :
- 694
- Database :
- Academic Search Index
- Journal :
- Journal of Alloys & Compounds
- Publication Type :
- Academic Journal
- Accession number :
- 119846669
- Full Text :
- https://doi.org/10.1016/j.jallcom.2016.10.068