TY - JOUR
T1 - High capacity group-15 alloy anodes for Na-ion batteries: electrochemical and mechanical insights
AU - Mortazavi , Majid
AU - Ye, Qiongjie
AU - Birbilis, Nick
AU - Medhekar, Nikhil V
PY - 2015
Y1 - 2015
N2 - 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.
AB - 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.
UR - http://goo.gl/FsbSYq
U2 - 10.1016/j.jpowsour.2015.03.051
DO - 10.1016/j.jpowsour.2015.03.051
M3 - Article
VL - 285
SP - 29
EP - 36
JO - Journal of Power Sources
JF - Journal of Power Sources
SN - 0378-7753
ER -