Increased cycling efficiency and rate capability of copper-coated silicon anodes in lithium-ion batteries

• Published in: Journal of power sources Vol. 196; no. 1; pp. 393 - 398
• Main Authors: Sethuraman, Vijay A., Kowolik, Kristin, Srinivasan, Venkat
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2011; Elsevier
• Subjects: Alloy anodes; ANODES; Applied sciences; BATTERIES; Coating; COATINGS; Copper; Copper coating; Cycles; Cycling efficiency; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrodes; ELECTRONIC PRODUCTS; Electronics; Equivalence; Exact sciences and technology; Lithium-ion batteries; Rate capability; Silicon; Silicon anodes; THIN FILMS; Lithium-ion batteries; Alloy anodes; Silicon anodes; Copper coating; Cycling efficiency; Rate capability; Performance evaluation; Cycling; Anode; Alkaline storage battery; Secondary cell; Coated material; Lithium battery; Silicon; Copper
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2010.06.043

Cycling efficiency and rate capability of porous copper-coated, amorphous silicon thin-film negative electrodes are compared to equivalent silicon thin-film electrodes in lithium-ion batteries. The presence of a copper layer coated on the active material plays a beneficial role in increasing the cycling efficiency and the rate capability of silicon thin-film electrodes. Between 3C and C/8 discharge rates, the available cell energy decreased by 8% and 18% for 40
nm copper-coated silicon and equivalent silicon thin-film electrodes, respectively. Copper-coated silicon thin-film electrodes also show higher cycling efficiency, resulting in lower capacity fade, than equivalent silicon thin-film electrodes. We believe that copper appears to act as a glue that binds the electrode together and prevents the electronic isolation of silicon particles, thereby decreasing capacity loss. Rate capability decreases significantly at higher copper coating thicknesses as the silicon active material is not accessed, suggesting that the thickness and porosity of the copper coating need to be optimized for enhanced capacity retention and rate capability in this system.