SnCo nanowire array as negative electrode for lithium-ion batteries

• Published in: Journal of power sources 2011-02, Vol.196 (3), p.1469-1473
• Main Authors: Ferrara, Germano, Damen, Libero, Arbizzani, Catia, Inguanta, Rosalinda, Piazza, Salvatore, Sunseri, Carmelo, Mastragostino, Marina
• Format: Article
• Language: English
• Subjects: Anode; Applied sciences; Arrays; Channels; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrodes; Exact sciences and technology; Lithium-ion batteries; Lithium-ion battery; Membranes; Nanocomposites; Nanomaterials; Nanowire; Nanowires; Tin; Tin–cobalt alloy
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2010.09.039

Amorphous SnCo alloy nanowires (NWs) grown inside the channels of polycarbonate membranes by potentiostatic codeposition of the two metals (SnCo- PM) were tested vs. Li by repeated galvanostatic cycles in ethylene carbonate-dimethylcarbonate – LiPF 6 for use as negative electrode in lithium ion batteries. These SnCo electrodes delivered an almost constant capacity value, near to the theoretical for an atomic ratio Li/Sn of 4.4 over more than 35 lithiation–delithiation cycles at 1 C. SEM images of fresh and cycled electrodes showed that nanowires remain partially intact after repeated lithiation–delithiation cycles; indeed, several wires expanded and became porous. Results of amorphous SnCo nanowires grown inside anodic alumina membranes (SnCo- AM) are also reported. The comparison of the two types of NW electrodes demonstrates that the morphology of the SnCo- PM is more suitable than that of the SnCo- AM for electrode stability over cycling. Optimization of NW technology should thus be a promising route to enhancing the mechanical strength and durability of tin-based electrodes.