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4596127 
Journal Article 
High capacity group-15 alloy anodes for Na-ion batteries: Electrochemical and mechanical insights 
Mortazavi, M; Ye, Q; Birbilis, N; Medhekar, NV 
2015 
Yes 
Journal of Power Sources
ISSN: 0378-7753 
285 
29-36 
WOS:000354140800004 
Group-15 elements phosphorus, arsenic, antimony and bismuth offer the prospect of serving as functional alloying elements for developing high-capacity alloy anodes for sodium-ion batteries (NIBs). Here we obtain concentration-dependent electrochemical properties of sodium (Na) alloys with group-15 elements using first principles calculations. Since Na intercalation in these alloys is accompanied by a substantial volume expansion that can lead to mechanical failure and loss of capacity, we have also obtained a full set of concentration-dependent elastic properties for a single crystal as well as a polycrystalline microstructure. We find that sodiation of these alloys results in their significant elastic softening by as large as 60%. In contrast to the group-14 alloys that are also being explored as anodes of NIBs, the elastic softening in group-15 alloys varies in a non-monotonic manner with Na concentration, and more importantly, the maximum degradation of elastic properties does not necessarily occur at full sodiation. Our results provide crucial insights into the electrochemical and mechanical response of these alloys to Na intercalation, thus contributing to the design of failure-resistant architectures of high capacity NIBs. (C) 2015 Elsevier B.V. All rights reserved. 
Na-ion batteries (NIBS); Alloy anodes; Electrochemical properties; Elastic properties; Density functional theory (DFT)