▎ 摘　　要

NOVELTY - Pyrophosphate composite material having a core-shell structure, where the core part comprising sodium vanadium pyrophosphate and graphite, the sodium vanadium pyrophosphate has a spherical or quasi-spherical structure and has a porous structure, and the graphene is filled in the porous structure, the shell part is a graphene layer covering the surface of the vanadium pyrophosphate, the content of the graphene and the graphene layer in the pyrophosphate composite material is 1-10 wt.%. USE - The pyrophosphate composite material is useful in preparing sodium ion battery anode including anode active layer or a sodium ion battery cathode including cathode active layer (all claimed). ADVANTAGE - The pyrophosphate composite material has good sodium ion diffusion characteristics, higher reversible specific capacity, good cycle stability and magnification characteristics. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing the pyrophosphate composite material comprising mixing the sodium source, phosphorus source, vanadium source and de-ionized water to obtain the first mixed solution, adding graphene oxide into the first mixed solution to obtain a second mixed solution, performing spray drying or freeze drying to the second mixed solution to obtain the precursor powder, and calcining the precursor powder; and (2) sodium ion battery includes a anode and a cathode, and a separator provided between the anode and the cathode for separating the anode and the cathode, comprising anode contains the pyrophosphate composite material, the cathode contains the pyrophosphate composite material.