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Author Wang, Qiannan ♦ Zhu, Ding ♦ Zhou, Wanhai ♦ Zhong, Chenglin ♦ Wu, Chaoling ♦ Chen, Yungui
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ ALUMINIUM ALLOYS ♦ COBALT ADDITIONS ♦ ELECTROCHEMISTRY ♦ HEAT TREATMENTS ♦ HEXAGONAL LATTICES ♦ HYDROGEN ♦ HYDROGEN STORAGE ♦ HYSTERESIS ♦ IRON ADDITIONS ♦ MANGANESE ALLOYS ♦ MICROSTRUCTURE ♦ NICKEL ALLOYS ♦ PERFORMANCE ♦ POTASSIUM HYDROXIDES ♦ SOLIDIFICATION ♦ TEMPERATURE DEPENDENCE ♦ THERMODYNAMIC PROPERTIES
Abstract Highlights: • Effects of four different preparation processes were studied at 20/60 °C. • All NS + HT, RS and RS + HT processes can optimize the thermodynamic performance. • The HT process can provoke the precipitation of A{sub 2}B{sub 7} and leads to a poor cycling life. • Al exhibits the most remarkable dissolution for all the alloys, especially at 60 °C. - Abstract: In order to optimize the microstructure and high temperature electrochemical performances of low-cost AB{sub 5}-type Ml(NiMnAl){sub 4.2}Co{sub 0.3}Fe{sub 0.5} hydrogen storage electrode alloys, four different preparation methods including normal solidification (NS), normal solidification and 900 °C heat treatment (NS + HT), rapid solidification (RS), rapid solidification and 900 °C heat treatment (RS + HT) were adopted in this work. All alloys exhibit CaCu{sub 5} type hexagonal structure and there is a small amount of A{sub 2}B{sub 7} phase in NS + HT and RS + HT alloys. It is found the using of HT process can decrease the hydrogen equilibrium plateau pressure, the plateau slope and hysteresis at 40, 60 and 80 °C. The NS + HT and RS + HT alloys also possess better activation, high rate discharge performance, larger discharge capacity, but poor cycling performance due to the existence of A{sub 2}B{sub 7} phase which can accelerate dissolution of Ni, Mn and Fe elements in KOH alkaline electrolyte. The RS process can make alloy exhibit the best cycling performance especially at 60 °C.
ISSN 00255408
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-04-15
Publisher Place United States
Journal Materials Research Bulletin
Volume Number 76


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