Sn-Co nanowire-based anodes for lithium-ion batteries

Abstract

The demand of improvement in lithium-ion battery technology in terms of specific capacity and safety has stimulated the search for anode materials alternative to graphite. Among them, tin-based materials have been widely studied because tin can intercalate lithium up to atomic ratio Li/Sn of 4.4 to deliver a impressive specific capacity of 993 mAhg−1 (while graphite gives 372 mAhg−1). Unfortunately the high volume change of about 300%, which is related to the insertion/removal of lithium, causes the alloy pulverization and loss of electric contact that causes a poor cycle life. The synthesis of nanometric materials, intermetallic compounds and carbon composites are strategies that have been pursued to reduce this drawback. In the present study, nanowires of SnCo amorphous alloy grown inside the channels of polycarbonate membrane by potentiostatic deposition were tested as anode for lithium-ion batteries with galvanostatic charge/discharge cycles, demonstrating a capacity corresponding to tin theoretical one stable for over 30 cycles. Even results of nanowires of the same alloy grown on alumina membrane are reported as comparison1. Reference 1. G. Ferrara, C. Arbizzani, L. Damen, R. Inguanta, S. Piazza, C. Sunseri, M. Mastragostino, Nanostructured anode and cathode materials for Li-ion batteries, CIMTEC 2010 5th Forum on New Materials, Montecatini, Italy, June 13-18, 2010