Mn2P2O7 anode material of core-shell structured lithium ion battery and preparation method thereof

Abstract

The invention relates to a Mn2P2O7 anode material of a core-shell structured lithium ion battery and a preparation method thereof. The Mn2P2O7 is prepared according to the following steps of: (1) dissolving an organic manganese source and a phosphorus source in deionized water to obtain a mixed solution; (2) adjusting a pH value to be 3 to 8; (3) placing the solution in a water bath at 60 to 90 DEG C, and stirring the solution for 10 to 30 hours to form uniform gel; (4) drying the gel for 4 to 15 hours at 60 to 110 DEG C to obtain a Mn2P2O7 precursor; and (5) placing the Mn2P2O7 precursor in a non-oxidizing atmosphere, sintering the Mn2P2O7 precursor at 350 to 700 DEG C for 4 to 14 hours, and cooling the product to the room temperature, thereby obtaining the Mn2P2O7 anode material of the core-shell structured lithium ion battery. The nanometer rod of the Mn2P2O7 is of a core-shell structure and has high specific area, thereby being favorable for ion transmission and infiltration of an electrolyte to an electrode material; and moreover, the conductivity of the nanometer rod is greatly improved due to uniformly-coated amorphous carbon, and the electrochemical performance of the material is excellent.

Description

Technical field [0001] The present invention involves a lithium -ion battery negative material and its preparation method, which specifically involves a core shell structure lithium -ion battery negative pole material marcate and their preparation methods. Background technique [0002] The energy density of lithium -ion batteries mainly depends on the output voltage and ratio capacity, and these also depend on the electrochemical properties of electrode materials. One of the keys to developing ideal lithium ion batteries is to find appropriate electrolytic materials. Among themPowerful materials for ionic electrode materials.The development of low -voltage, high capacity, long life, and safe and stable negative materials are the top priority of the attention of many researchers.The traditional graphite negative electrode limits the development of lithium ion batteries to high -capacity targets due to low capacity (for 372mAh / g). The new graphene is limited to its expansion due to...

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Problems solved by technology

However, there is no report on the application of the synthesized manganese pyrophosphate to lithium-ion battery anode materials.

CN103539098A discloses a method for preparing manganese pyrophosphate nanosheets. When the manganese pyrophosphate nanosheets prepared according to the method are used in lithium-ion batteries, due to the disproportionation reaction of Mn in the electrolyte during charge and discharge, the disproportionation of Mn will occur. Dissolution leads to a decrease in the electrochemical performance of the material, and the nanosheet morphology greatly increases the contact area between the active material and the electrolyte due to its large specific surface area. Therefore, the nanosheet manganese pyrophosphate will promote the dissolution of Mn, and the manganese pyrophosphate Poor conductivity, which will affect the electrochemical performance of the material when used as an electrode material for lithium-ion batteries

[0004] CN104091953A discloses a vanadium pyrophosphate, a negative electrode material for lithium ion batteries, and its preparation method. A reducing agent must be used in the raw materials, and the final product has a nano-sheet shape without carbon coating, which makes its conductivity poor.

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