Featuring surface sodium storage properties of confined MoS2/bacterial cellulose-derived carbon nanofibers anode

A facile strategy has been designed for the synthesis of nanoflower-like MoS2/carbon nanofibers (CNFs) derived from bacterial cellulose. CNFs can well retain the fibrous structure with thickness of 21 nm. The formation of few-layered ultrathin MoS2 nanosheets crosslinked with CNFs due to confined growth, leading to more active surface area. Among the varied compositions of MoS2/CNFs, the largest specific surface area is 35.1 m(2) g(-1). In addition, 3D porous architecture of CNFs can provide sufficient space to accommodate the volume change of MoS2 during sodiation/desodiation, while the conducive network facilitates electron and ion transfer. The morphology evolution of MoS2/CNFs can be observed by tuning the amount of CNFs. The optimized MoS2/CNFs possesses expanded interlayer spacing of 0.71 nm, while the CNFs content is 10.24 wt%. As anodes for sodium ion batteries, it can deliver a capacity of 509 mA h g(-1) at 0.1 A g(-1), and maintains a high discharge capacity of 368 mA h g(-1) after 400 cycles at 6.25 A g(-1). Furthermore, reaction kinetics is analyzed, demonstrating the superior cycling stability and rate performance are rooted in the capacitive behavior. And the contribution ratio is calculated to be 72.7% at 1 mV s(-1).