▎ 摘　　要

NOVELTY - The composite material comprises metal layer and metal phosphide layer respectively coated by a carbon source. The metal layer is coated on the outside of the metal phosphide layer or embedded in the metal phosphide layer. The nano metal layer and the metal phosphide layer together form a double-layer concentric fibrous structure. The metal in the metal layer is tin, iron, antimony, copper or nickel. The metal phosphide layer is tin phosphide, iron phosphide (FeP4, Fe3P, FeP2), antimony phosphide, copper phosphide (CuP2, Cu3P2), or nickel phosphide (NiP, Ni3P2). The carbon source is polyvinylpyrrolidone or polyacrylonitrile. USE - Phosphorus-based composite material is used for sodium ion secondary battery cathode (claimed) used in large-scale renewable energy storage device. ADVANTAGE - The phosphorus-based composite material exhibits good cycle stability and multiplying power performance, and reduces impedance of the composite material by electrochemical impedance spectroscopy test. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) preparation method of phosphorus-based composite material comprising adding metal salt into the solvent, fully dissolving, adding spinning raw liquid, continuously stirring, dissolving the phosphide and metal salt in the solvent in batches, and then adding obtained spinning raw liquid, continuously stirring, electrostatic spinning the metal layer spinning solution and the metal phosphide layer spinning solution at 30-50degrees Celsius, humidity of 15-40 %, positive voltage of 15-30 kV, and negative voltage of -3 to -1 kV, carbonizing the obtained material, and preparing the phosphorus-based composite material with the same core structure; (2) sodium ion secondary battery cathode comprising 50-99.5 wt.% phosphorus-based composite material, 0.1-40 wt.% conductive agent and 0.1-40 wt.% binder; and (3) secondary battery.