3-D Si/carbon nanofiber as a binder/current collector-free anode for lithium-ion batteries

To increase the energy storage capacity of Li-ion batteries (LIBs), novel anode materials having excellent electrochemical properties need to be intensively studied. In particular, although Si as an anode active material has a high theoretical capacity compared to graphite, Si has exhibited irreversible cycle properties due to its volumetric expansion during the charge/discharge process. In this study, a 3-D paper-type Si-carbon nanofiber-composite electrode (Si/CNF-P) as a binder/current collector-free anode for LIBs was prepared using an electrospinning method. The Si/CNF-P exhibited a high initial capacity of 1957 mAh g−1 at 2 A g−1 and maintained 1187 mAh g−1 (retention rate of 60.6%) for 400 cycles. The enhanced performance of Si/CNF-P as an anode without a current collector and a binder in LIBs can be mainly attributed to the voids produced by cross-linked CNFs as a matrix and the electrochemical reaction of Si NPs on the CNFs without additional collapse of the electrode.