The silicon–carbon nanofibers-carbonized yeast powder composites with excellent electrochemical properties as lithium-ion anode materials

Abstract

Silicon–carbon nanofibers-carbonized yeast powder composite (SCNFs/CYP) was fabricated using the electrostatic spinning and hydrothermal processes. Experimental results show that the carbon nanofibers can restrain the volume expansion of silicon in the electrochemical process and the microporous structure of carbonized yeast powder can increase the specific surface area and promote the penetration of electrolyte. The compound was cyclically tested at charge–discharge rate of [Formula: see text]C, and the first charge/discharge capacity was 1725 and 1732 mAh/g. Although it is lower than the capacity of single structure silicon–carbon nanofibers (SCNFs), with the increase of the number of cycles, the capacity of charging and discharging has been greatly improved, and it can be maintained at 1656 mAh/g after 180 cycles. The [Formula: see text] after 1 cycle, 10 cycles and 100 cycles were 486, 286.5 and 231 [Formula: see text], from which we can see that the SCNFs–CYP has lower overall impedance values as the cycle increases. This indicated that the addition of carbon nanofibers and carbonized yeast powder inhibited the volume expansion and increased the specific surface area, providing more electrical contact sites.