The influences of the preparation methods on the lithium iron(II) phosphate-lithium vanadium phosphate mixing materials

Lithium iron(Ⅱ) phosphate lithium vanadium phosphate mixing materials(LFVP) were prepared by "physical blending method" and "chemical blending method",and the obtained materials were characterized by crystal structure,carbon analysis,grain size distribution,morphology and conductivity.We found in the process of "physical blending method",the strong mechanical force impacted the material's crystal structures and the carbon coating on the surface of the materials;a few materials grains may also agglomerate.The good crystal structural material synthesized by "chemical blending method" has more excellent electrochemical performance,its discharge capacity is 194.5 and 85mAh/g at 0.1 and 20C respectively;when the material was discharged at 1C for 1000 times,the capacity also remained 120mAh/g,so it has important practical value.All of the excellent electrochemical performances can be attributed to its fine and uniformly distributed materials grains,carbon-coating,and the trace impurities.Therefore "chemical blending method" is the preferred method to prepare LFVP.