Electrospun Fe1-xS@nitrogen-doped carbon fibers as anode material for sodium-ion batteries

Abstract

Iron sulfide is a potential anode material for sodium-ion batteries because of its abundant natural resources and high theoretical specific capacity. However, they show poor cycling performance due to the serious volume change of iron sulfide materials during the process of charge and discharge. In this work, Fe1-xS particles are encapsulated in nitrogen-doped 1D carbon fiber material by an electrospinning/high-temperature vulcanization process. The carbon fiber skeleton effectively stabilized the structure of the material; The heteroelement doped carbon improved the electrical conductivity properties and capacitive sodium storage performance. Owing to the unique structure of nitrogen-doped 1D carbon fiber, the material obtains good cycling stability and rate capability. The optimized Fe1-xS@ nitrogen-doped carbon fibers (Fe1-xS@NCFs) material was used as the anode of the sodium-ion batteries and maintained a discharge capacity of 382 mAh g-1 after 100 cycles at 0.1 A g-1 and 330 mAh g-1 after 150 cycles at 1 A g-1.