Carbon nanofibers with uniformly embedded silicon nanoparticles as self-standing anode for high-performance lithium-ion battery

Abstract

Electrospinning has been used as a convenient technology to produce high-energy and self-standing anodes for lithium-ion batteries (LIBs) by encapsulating silicon nanoparticles (Si/NPs) into carbon nanofibers (CNF). However, the inhomogeneous distribution of Si/NPs in CNF results in low coulombic efficiency, rapid capacity decay and slow kinetics during cycling process which hinder the practical application of this promising composite anode. In this work, a principle of universal design is applied to the manufacture of Si-CNF composites, in this way, a self-standing electrode with homogeneous distribution of Si/NPs in CNF (Si//PCNF-15) is developed by introducing triblock copolymer Pluronic P123 (polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer) as dispersant and pore directing agent. As anode of LIBs, the Si//PCNF-15 exhibits outstanding electrochemical performance and considerable flexibility due to the homogeneous dispersion of Si nanoparticles and high graphitization of the carbon network. As results, a specific capacity of 1074.8 mAh g−1 at 0.3 A g−1 and a rate capacity of 236.1 mAh g−1 at 10 A g−1 have been delivered when it is explored as a self-standing anode for LIBs. This work provides a universal approach for developing self-standing anodes of composite fibers with nanoparticles dispersed homogeneously in CNF.