Effect of Ni Substitution for Co on the Electrochemical Properties of La0.75Mg0.25Ni2.7+xCo0.4-xMn0.1Al0.3(x= 0–0.4) Hydrogen Storage Alloys Synthesized by Chemical Co-precipitation plus Reduction Method

Zhu, Wen; Tan, Cong; Xu, Jinbang; Li, Zhenxuan

Abstract

The feasibility of substituting nickel for cobalt in La-Mg-Ni-based hydrogen storage alloys to reduce material costs and improve
electrochemical properties is investigated. The series of alloys with the chemical formula La0.75Mg0.25Ni2.7+xCo0.4-xMn0.1Al0.3
(x = 0–0.4) that reflects the gradual substitution of Ni for Co are prepared by chemical co-precipitation plus reduction method.
The detailed synthesis process, structure, morphology, electrochemical performance, and kinetic properties of the resulting alloy
electrodes are discussed in terms of the variation in substitution amount of Ni for Co. Results reveal that the hydrogen storage alloy
substituted with x = 0.1 exhibits the best overall electrochemical performance among all investigated samples, whereas the complete
substitution of Ni for Co has no significant effect on electrochemical performance. Based on these results, a mechanism underlying
the effect of substituting Ni for Co on the electrochemical performance of the resulting alloy is discussed in detail and effectively
verified by conducting three electrochemical kinetic experiments. Complete substitution of Ni for Co is found to be suitable for
reducing material costs and improving the overall electrochemical performances of La-Mg-Ni-based hydrogen storage alloys.

Citation

Zhu, W., Tan, C., Xu, J., & Li, Z. (2014). Effect of Ni Substitution for Co on the Electrochemical Properties of La0.75Mg0.25Ni2.7+xCo0.4-xMn0.1Al0.3(x= 0–0.4) Hydrogen Storage Alloys Synthesized by Chemical Co-precipitation plus Reduction Method. Journal of The Electrochemical Society, 161(1), A89-A96. https://doi.org/10.1149/2.043401jes

• Journal Article Type: Article
• Acceptance Date: Nov 1, 2013
• Online Publication Date: Nov 13, 2013
• Publication Date: 2014
• Deposit Date: Aug 22, 2019
• Journal: Journal of The Electrochemical Society
• Print ISSN: 0013-4651
• Electronic ISSN: 1945-7111
• Publisher: Electrochemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 161
• Issue: 1
• Pages: A89-A96
• DOI: https://doi.org/10.1149/2.043401jes
• Keywords: Renewable Energy, Sustainability and the Environment; Electrochemistry; Materials Chemistry; Electronic, Optical and Magnetic Materials; Surfaces, Coatings and Films; Condensed Matter Physics
• Public URL: https://nottingham-repository.worktribe.com/output/2471860
• Publisher URL: http://jes.ecsdl.org/content/161/1/A89