Self-Standing Film Assembled using SnS–Sn/Multiwalled Carbon Nanotubes Encapsulated Carbon Fibers: A Potential Large-Scale Production Material for Ultra-stable Sodium-Ion Battery Anodes

High-energy sodium-ion batteries have a significant prospective application as a next-generation energy storage technology. However, this technology is severely hindered by the lack of large-scale production of battery materials. Herein, a self-standing film, assembled with SnS–Sn/multiwalled carbon nanotubes encapsulated in carbon fibers (SnS–Sn/MCNTs@CFs), is prepared using ball milling and electrospinning techniques and used as sodium-ion battery anodes. To compensate the poor internal conductivity of SnS–Sn nanoparticles, MCNTs are used to interweave SnS–Sn nanoparticles to improve the conductivity. Moreover, the designed three-dimensional carbon fiber conductive network can effectively shorten the diffusion path of electron/Na+, accelerate the reaction kinetics, and provide abundant active sites for sodium absorption. Benefiting from these unique features, the self-standing film offers a high reversible capacity of 568 mA h g–1 at 0.1 A g–1 and excellent cycling stability at 1 A g–1 with a reversible capacity of 359.3 mA h g–1 after 1000 cycles. In the sodium-ion full cell device, the capacity is stable at 283.7 mA h g–1 after 100 cycles at a current of 100 mA g–1. This work provides a new strategy for electrode design and facilitates the large-scale application of the sodium-ion battery.