Synthesis of Free-Standing Tin Phosphide/Phosphate Carbon Composite Nanofibers as Anodes for Lithium-Ion Batteries with Improved Low-Temperature Performance.

Free-standing tin phosphide/phosphate carbon composite nanofiber mats of unique nanostructure have been successfully synthesized by electrospinning and partially reducing the phosphate-containing precursors. An unusual effect of the Sn:P molar ratio in the precursor solution on the structure and physical-electrochemical properties of the material is observed. Physical characterizations, including X-Ray diffraction (XRD), Raman spectroscopy, X-Ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), confirm the formation of tin phosphide/phosphate nanoparticles of P-rich inner Sn P layer and Sn-rich outer layer uniformly distributed within carbon nanofiber matrix when the Sn:P=1:1.