Fabrication of hollow C/Si nanofibers as binder-free anodes for lithium-ion batteries

Abstract

Silicon is the anode material with great prospects thanks to its high theoretical specific capacity and lower lithiation/delithiation voltages. Nonetheless, the poor cycling stability of silicon, which is attributed to the considerable volume changes during lithiation and delithiation, restricts its practical application in energy storage technologies. Within this work, C/Si nanofibers with a hollow structure were prepared using electrospinning combined with magnetron sputtering. The hollow structure provides essential buffer space to alleviate the volume changes of silicon during the cycling process, and the thinner surface layer accelerates lithium-ion diffusion by narrowing the diffusion channel. The hollow C/Si nanofibers (H-C/Si NFs) exhibit superior lithium storage performance, retaining a capacity of 1262.9 mA h g⁻¹ after 80 cycles at 0.1 A g⁻¹ and demonstrating excellent rate capability with 654.2 mA h g⁻¹ at 2 A g⁻¹.