Preparation method of metal doped lithium manganese phosphate/graphene/carbon composite material

Abstract

The invention discloses a preparation method of a metal doped lithium manganese phosphate / graphene / carbon composite material. By adopting the method, the graphene is added in the preparation process of the lithium manganese phosphate to replace partial conductive carbon black; and a precursor which is a mixture of three solutions is transferred to a reaction tank and is subjected to solvothermal reaction at 160-300 DEG C for 1-20 hours to obtain the graphene in-situ composite lithium manganese phosphate material. According to the preparation method disclosed by the invention, the surface-contact compounding of graphene and lithium manganese phosphate is achieved by taking advantage of the flexibility characteristic of graphene, and the electronic conductivity of the lithium manganese phosphate is improved by taking advantage of the extremely high conductivity of graphene. By adopting the preparation method disclosed by the invention, not only is the intrinsic electronic conductivity of the composite material improved, but also a graphene film layer with extremely high conductivity is uniformly coated on the surface of the lithium manganese phosphate material, the graphene and the conductive carbon black together form a three-dimensional conductive network, and therefore the electrochemical performance of the lithium manganese phosphate material is obviously improved, and the composite material can be used as the anode material of a lithium ion battery.

Description

technical field [0001] The invention belongs to the preparation of lithium-ion battery cathode materials in the field of electrochemistry and new energy materials, and specifically relates to a preparation method of a metal-doped lithium manganese phosphate / graphene / carbon composite material. Background technique [0002] The progress of society and the continuous growth of people's needs make clean and efficient energy more and more people's attention. On the one hand, for many clean new energy sources (such as solar energy, wind energy, tidal energy, and geothermal energy), large-capacity energy storage devices are required to store these energy sources for use when people need them, and lithium-ion secondary batteries have become the best choice. . On the other hand, replacing fuel vehicles with electric vehicles has become the key development direction of various countries. Battery technology is the core of electric vehicle production and plays a vital role in the devel...

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Problems solved by technology

[0005] The purpose of the present invention is to address the shortcomings of the existing technology of lithium manganese phosphate materials such as poor electronic conductivity, serious polarization during charge and discharge, low reversible capacity, poor cycle stability, and severe attenuation. It is proposed to add graphene when preparing lithium manganese phosphate. Instead of some conductive carbon black, use graphene and conductive carbon black to form a three-dimensional conductive network to improve the electrochemical performance of lithium manganese phosphate materials

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