Evaluations of Advanced Si-Mo Composite Anodes Using RF/DC Magnetron Sputtering for Bulk Lithium Ion Batteries

Lithium-ion batteries have become the most important rechargeable battery for portable electronics and electric and plug-in hybrid electric vehicles [1], with high energy density materials being of considerable interest. Numerous replacements for the graphite anode have been investigate, with silicon [2, 3] being one of the most attractive since its high theoretical specific capacity of 4200 mAhg-1 is more than 10 times larger than graphite (372 mAhg-1) [4]. However, lithium silicon alloys usually exhibit rapid capacity loss during cycling. It has been experimentally indentified that volume expansion by 300~400 % of bulk Si during lithium ion insertion and extraction result in cracking and pulverization, and consequently the capacity failure