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Surface modification method for spherical graphite negative material

A spherical graphite, surface modification technology, applied in the direction of graphite, battery electrodes, electrical components, etc., can solve the problems of not easy to obtain a uniform surface oxide layer, waste liquid discharge pollutes the environment, poor process stability, etc., to achieve the elimination of surface Defects, improved reversible capacity, and easy operation

Active Publication Date: 2015-04-15
河南克莱威纳米碳材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The liquid phase oxidation method uses ammonium sulfate, nitric acid, KClO 3 Such a strong oxidant is used to treat the surface of spherical graphite. This process is convenient to control the degree of oxidation, and the product has good uniformity and stability. It is suitable for industrial production. However, the use of strong acidic oxidants brings problems such as poor working environment and environmental pollution caused by waste liquid discharge.
The gas-phase oxidation method mainly uses air, oxygen, ozone, etc. as the oxidant, and realizes it through the gas-solid phase interface reaction. Its advantages are simple process and no environmental pollution. The main problems are low oxidation efficiency and poor process stability. It is not easy to obtain a uniform surface oxide layer

Method used

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  • Surface modification method for spherical graphite negative material
  • Surface modification method for spherical graphite negative material
  • Surface modification method for spherical graphite negative material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Put 50g of graphite in a vacuum drying oven at 100°C for preheating and drying for 40min, then place it in a gas phase oxidizer with a gas flow rate of 150L / min, oxidize at 600°C for 15min, and let it stand for 5min; ultrasonic treatment uses 50g / L (graphite / ethanol) Ratio, 800W ultrasonic treatment for 10min; then centrifugal filter at 2000r / min for 10min. The semi-finished product can be finished by placing it in a vacuum oven at 80°C for 30 minutes.

Embodiment 2

[0023] Place 50g of graphite in a vacuum drying oven at 80°C for preheating and drying for 60 minutes, then place it in a gas phase oxidizer with a gas flow rate of 150L / min and 500°C for 30 minutes, and let it stand for 5 minutes; ultrasonic treatment uses 50g / L (graphite / ethanol) Ratio, 600W ultrasonic treatment for 20min; then centrifugal filter at 1000r / min for 10min. The semi-finished product can be finished by placing it in a vacuum oven at 60°C for 60 minutes.

Embodiment 3

[0025] Put 50g of graphite in a vacuum drying oven at 150°C for preheating and drying for 30 minutes, then place it in a gas phase oxidizer with a gas flow rate of 150L / min, oxidize at 400°C for 45 minutes, and let it stand for 5 minutes; ultrasonic treatment uses 50g / L (graphite / ethanol) Ratio, 400W ultrasonic treatment for 30min; then centrifugal filter at 1000r / min for 20min. The semi-finished product can be finished by placing it in a vacuum oven at 60°C for 45 minutes.

[0026] The morphology of the finished graphite obtained by the method of the present invention can be observed by a SEM scanning electron microscope, and the model is Quanta200. Figure 1~3 Corresponding to Embodiments 1-3 of the inventive method.

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Abstract

The invention discloses a surface modification method for a spherical graphite negative material. The method comprises the following steps of: carrying out surface oxidation modification treatment on the spherical graphite negative material by using oxidizing gas, and eliminating the defect structure on the surface of spherical graphite by using a gas phase, namely, conducting steps of preheating, drying, gas phase oxidation, ultrasonic treatment, filtering separation, finished product drying, and the like. The method is simple and convenient to operate, the production efficiency is high, the utilization rate of a spherical graphite material is sufficiently improved, and the oxidation uniformity of the surface of the spherical graphite is improved; by utilizing the oxidation method, the surface defect on the surface of the spherical graphite is eliminated, the compatibility of the graphite and electrolyte is improved, the cycle life is prolonged, nano pores are obtained, and the reversible capacity of the negative material is improved. The surface modification method can be popularized to various gas phase modified graphite materials, and requirements of industrial production are met.

Description

technical field [0001] The invention belongs to the technical field of material processing and relates to a material surface processing method. Background technique [0002] Graphite material has good electrical conductivity, high crystallinity, and good layered structure, suitable for lithium intercalation-deintercalation, with a theoretical capacity of 372 mAh g -1 , low irreversible capacity, charge and discharge efficiency above 90%, is currently the most widely used anode material for lithium-ion batteries. However, the defect structure contained in graphite itself leads to unsatisfactory electrochemical performance. Seek appropriate modification treatment to eliminate the structural defects of graphite, which is beneficial to the practical application of graphite in lithium batteries. For example, the electronic state of spherical graphite can be changed through surface oxidation treatment, and the oxygen content on the graphite surface can be increased at the same t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B31/04H01M4/587C01B32/21
CPCY02E60/10
Inventor 李克廖健南王东华
Owner 河南克莱威纳米碳材料有限公司