In-situ nano Fe3O4@C composite porous lithium ion battery anode material and preparation method thereof

Abstract

The invention discloses an in-situ nano Fe3O4@C composite porous lithium ion battery anode material and a preparation method thereof and belongs to the technical field of production of lithium ion battery electrode materials. On the basis of polyhydroxy structure features of citrate, the in-situ Fe3O4@C composite porous lithium ion battery anode material with Fe3O4 obtained through carbonization dispersed and distributed in a porous carbon framework is designed on the molecular scale with ferric citrate chelate as a precursor. The ferric citrate precursor is prepared with a complexing precipitation method and carbonized in the inert atmosphere, Fe<3+> produces Fe3O4 at in-situ sites, C6H5O7<3-> decomposes to form the carbon framework, the porous structure benefits from overflow of other decomposition products, the preparation condition is mild, the synthesis process is simple and controllable, and the cost is low. The synthesized electrode material can realize in-situ nano crystallization and dispersion distribution of Fe3O4, external carbon sources are not required, meanwhile, by the aid of the porous structure of carbon, the electron migration rate is increased, contact of an electrolyte and the electrode material is enhanced, the lithium storage performance of the electrode material is improved, the synergistic effect of Fe3O4 and the porous carbon structure is realized, andthe problems of significant capacity fading, poor cycle stability and the like caused by the Fe3O4 volume effect are solved effectively, so that the Fe3O4@C composite material has good electrochemical performance.

Description

technical field [0001] The present invention relates to a kind of nano Fe 3 o 4 @C An in-situ composite porous lithium-ion battery negative electrode material and a preparation method thereof belong to the field of lithium-ion battery materials. Background technique [0002] In response to the requirements of high energy density, long service life, safety performance and low cost for energy storage and power batteries, electrode materials for lithium-ion batteries have been extensively studied in recent years. However, the current commercial graphite carbon anode materials have a low theoretical capacity (372 mAh g -1 ), it is difficult to meet the needs of high energy density of lithium-ion batteries, so the development of new anode materials with high capacity, long cycle life and low cost is the main direction of current research. Fe 3 o 4 Theoretical capacity up to 924 mAh·g -1 , rich in reserves and high safety, so it has attracted much attention in the research p...

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Problems solved by technology

Although the above method can improve the electrochemical performance of electrode materials to a certain extent, its synthesis process requires additional carbon materials, or the synthesis process has high requirements and complicated process flow, and the above methods still have obvious volume expansion and particle agglomeration. The performance and cycle stability are poor, and the performance and cost requirements cannot be taken into account, which greatly limits the Fe 3 o 4 Production application and promotion in the lithium-ion battery material market

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