Dual-buffered SnSe@CNFs as negative electrode with outstanding lithium storage performance

Alloying with Se has been recently found to be an effective way to improve the cycling performance because the reduced-Se formations can act as a buffer matrix against the volume change of electrode for IVA materials or anchors S in Li-S batteries during cycling. In this paper, SnSe nanoparticles were dispersed within a carbon fiber matrix with ball milling and electrospinning methods. The uniform nano-architecture with SnSe nanoparticles homogeneously confined in the carbon matrix, which is revealed by X-ray powder diffraction and scanning electron microscope, provides a stable buffer and good electrical conductor for the lithiation/delithiation process. Moreover, Se-based phase acts as an additional stabilizer to alleviate Sn agglomeration during cycling. Such dual-buffered SnSe/C composites thus deliver large reversible capacity of 840 mAh/g with ultrastable cycling performance over 100 cycles and demonstrate good rate capacity.