Si/C composite nanofibers were prepared by electrospinning and carbonization using polyacrylonitrile (PAN) as the spinning medium and carbon precursor. The nanofibers were used as lithium-ion battery anodes to combine the advantages of carbon (long cycle life) and silicon (high storage capacity) materials. The effects of Si particle size, Si content, and carbonization temperature on the structure and electrochemical performance of the anodes were investigated. Results show that anodes made from a 15 wt.% Si/PAN precursor with a Si particle size of 30-50 nm and carbonization temperature of 800 degrees C exhibit the best performance in terms of high capacity and stable cycling behavior. It is demonstrated that with careful structure control, Si/C composite nanofiber anodes are a promising material for next-generation lithium-ion batteries. (C) 2012 Elsevier Ltd. All rights reserved.