Hierarchical Composite from Carbon Nanofibers Wrapped SnS Core-Shell Nanoparticles as an Anode for Lithium-Ion Batteries

The significant capacity loss and pulverization caused by the dramatic increase in volume of Sn-based anodes during redox reactions severely limit their practical application in lithium-ion batteries. Herein, with the ultralong cycle life and high capacity Sn-based compounds (SnS-C/NS@CNFs), a self-supporting anode was prepared by electrospinning followed by the calcination scheme, which is a superb material for lithium storage since the buffer matrix reduces the volume expansion of Sn. In this strategy, SnS nanoparticles are scattered into a porous carbon framework using Sn-MOFs as a pore-forming template, which allows for easier extraction-insertion of Li-ions due to their inherent layered structure. Moreover, the nitrogen and S-doped carbon nanofibers not only serve as a barrier to impede the aggregation and volume expansion of SnS during cycling but also act as electrical pathways to enhance the conductivity of the electrodes. Having profited from the desirable nanostructures, the flexible three-dimensional cross-linked nanofibers were straightly used as a self-supporting anode for LIBs, displaying ultralong cycle life (455.8 mAh/g after 1000 cycles at 1 A/g) and exceptional rate performance (481 mAh/g at 2 A/g). This work offers a reliable and efficient method for fabricating flexible self-standing and durable electrodes.