Electrochemical cycling stability of electrospun silicon/carbon nanofibers anode materials: A review

Abstract

Silicon (Si) is regarded as the promissing anode material owing to its high specific capacity and low lithiation potential. The large volume change and the pulverization of silicon during the lithiation/delithiation process hinder its direct energy storage application. This review focuses on the electrospun silicon/carbon (Si/C) nanofibers anode material of lithium-ion battery for long-term stable energy storage. The silicon is completely embedded in electrospinning-based carbon nanofibers to form the electrospun Si/C nanofibers. It not only creates pore space to buffer silicon volume expansion, but also prevents direct contact between silicon and electrolyte, consequently forming a stable solid electrolyte interface film. The electrospun Si/C nanofibers solve the pulverization issue of silicon to achieve cycling stability. Furthermore, the electrospun carbon nanofibers form a flexible conductive network for surrounding silicon by facilely introducing sacrificial polymers or template agents. The electrospun Si/C nanofibers ultimately promote the lithium-ion transport to achieve rate stability. The silicon source selection and microstructure regulation of the electrospun Si/C nanofibers are overviewed. The silicon sources include the direct utilization of silicon or silicon oxide particles as well as the indirect conversion of silicon-based precursors. The cycle stability regulation of various metal- and metal oxide-modified silicon composites and heterogeneous carbon materials-decorated electrospun Si/C nanofibers are summarized. In addition, the microstructure designs of the electrospun Si/C nanofibers associated with the improvement of long-term capacity retention are overviewed. The main challenges of the electrospun Si/C nanofibers anode materials are summarized, and the future perspectives are also proposed.