A graphite sheet/self-assembled nanometer cobalt tetraoxide lithium ion negative electrode material, preparation method and lithium battery using the same

Abstract

The embodiment of the invention discloses a graphite flake / self-assembled nanometer cobaltosic oxide lithium ion negative electrode material, its preparation method and a lithium battery using it. The preparation method comprises the following steps: weighing expanded graphite and DMF according to a ratio of 0.5-5g / L, and carrying out ultrasonic treatment to obtain a graphite flake solution; adding a proper amount of deionized water; weighing cobalt acetate tetrahydrate according to a ratio of the cobalt acetate tetrahydrate to the solvent DMF of 10-60g / L, and dissolving the cobalt acetate tetrahydrate in the solvent; stirring for dissolving, adding the above obtained solution into a hydrothermal tank, and carrying out heat insulation; and cooling to room temperature, cleaning the above obtained black sediment through using an alcohol solution by a centrifuge, and baking the cleaned black sediment until the obtained sample is dry. Co3O4 nanoparticles in the composite material prepared through the method are cubic particles with good crystallization and uniform size, the side length of the nanoparticles is about 4nm, the density of the nanoparticles is 2*10<13> / cm<2>, a gap between two adjacent nanoparticles is 1-10nm, and the nanoparticles are uniformly distributed on two surfaces of a graphite flake, so an extremely good lithium storage performance can be obtained.

Description

technical field [0001] The invention belongs to the field of lithium ion energy storage materials, and relates to a graphite flake / self-assembled nanometer cobalt tetraoxide lithium ion negative electrode material and a preparation method, and the material can be used for making lithium ion battery electrodes. Background technique [0002] Graphene (single-layer graphite sheet) and graphite sheet with fewer layers have good conductivity and large specific surface area. Graphene materials are used instead of traditional carbon materials for electrodes of lithium-ion batteries and supercapacitors, which have shown It has good capacity characteristics and charge and discharge characteristics. However, there are also some problems with a single graphene electrode, such as agglomeration and poor cycle stability. Therefore, the preparation of metal oxides on the surface of graphene as electrodes is a recent research hotspot. Using graphene's excellent conductivity and large spec...

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Problems solved by technology

This preparation of composite materials by the GO method and the recent method of reducing graphene oxide has the disadvantages of complex process and high cost. At the same time, the chemical modification of GO will reduce the conductivity of graphene, thereby weakening its performance as an electrode.

Deposited Co prepared in the presence of 3 o 4 The size is large, the size is not very uniform, and the coverage on the graphene surface is not high. These will definitely affect the characteristics of the electrode material

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