Silicon oxycarbide-carbon hybrid nanofibers: a promising anode for ultralong-cycle lithium ion batteries with high rate capability

Abstract The practical application of silicon oxycarbide (SiOC) based electrodes has been restricted by poor rate performance and under capacity retention on account of sluggish electronic and ionic transport of the SiOC glass. To tackle this issue, we synthesized silicon oxycarbide-carbon hybrid nanofibers by using an economically efficient approach, which involves several steps: electrospinning the PAN nanofibers (PNFs), grafting polysiloxanes onto the PNFs and thermal conversion of the silicone/PNFs (SPNFs). The obtained 1D nanostructure endows the hybrids electrode with rapid electron transfer kinetics, robust structural stability, fast lithium ion conduction, and efficient electronic pathway. When tested as an active electrode material, the hybrids electrode delivers a reversible specific capacity of 715.8 mAh g-1 at 1C (1C = 372 mA g-1), excellent high rate performance (422.1 mAh g-1 at 20C) and outstanding capacity retention capability of 95.4% after 2000 cycles at 10C. The results well testify the potential application of silicon oxycarbide-carbon hybrid nanofibers anode for the next-generation lithium ion batteries.