Simple fabrication of flexible electrodes with high metal-oxide content: electrospun reduced tungsten oxide/carbon nanofibers for lithium ion battery applications

Abstract

A one-step and mass-production synthetic route for a flexible reduced tungsten oxide–carbon composite nanofiber (WO_x–C-NF) film is demonstrated via an electrospinning technique. The WO_x–C-NF film exhibits unprecedented high content of metal-oxides (∼80 wt%) and good flexibility (the tensile strength of the specimen was 6.13 MPa) without the use of flexible support materials like CNTs or graphene. The WO_x–C-NF film is directly used as an anode in a lithium ion battery (LIB). Compared with previously reported tungsten oxide electrodes, the WO_x–C-NF film exhibits high reversible capacity (481 mA h g⁻¹_{total electrode}), stable cycle, and improved rate performance, without the use of additive carbon, a polymeric binder and a current collector. Moreover, control electrodes fabricated by conventional processes support the positive effects of both the freestanding electrode and metal-oxide embedded carbon 1-D nanofiber structure.