Netted gamma-aluminum oxide coated modified graphite negative electrode material as well as preparation method and application thereof

A graphite negative electrode and alumina technology, applied in the direction of negative electrode, active material electrode, battery electrode, etc., can solve the problems of low coulombic efficiency intercalation and extraction, lower battery energy density, high working voltage, etc., and achieve lithium intercalation dynamics improvement , small capacity loss, easy to expand the effect

Inactive Publication Date: 2021-09-07
DONGGUAN KAIJIN NEW ENERGY TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] For the traditional graphite negative electrode, the characteristics of low working potential (<0.2V) can easily lead to the phenomenon of lithium precipitation, which in turn causes the coulombic efficiency of lithium deposition and stripping to be lower than that of lithium intercalation and extraction, while continuously consuming active lithium ions and electrolytes. Lithium dendrites will also be formed to penetrate the battery separator, causing internal short circuits and bringing safety hazards
Although the new negative electrode material lithium titanate avoids this problem very well, its defects of high working voltage (1.55V) and low specific capacity (175mAh / g) seriously reduce the energy density of the battery

Method used

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  • Netted gamma-aluminum oxide coated modified graphite negative electrode material as well as preparation method and application thereof
  • Netted gamma-aluminum oxide coated modified graphite negative electrode material as well as preparation method and application thereof
  • Netted gamma-aluminum oxide coated modified graphite negative electrode material as well as preparation method and application thereof

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preparation example Construction

[0030] A method for preparing a reticular gamma-alumina coated modified graphite negative electrode material, comprising the steps of:

[0031] (1) Disperse a certain amount of graphite in deionized water, stir evenly, and mark it as A solution;

[0032] (2) A certain amount of aluminum salt is dissolved in deionized water, marked as B solution;

[0033] (3) Slowly drop the B solution into the A solution under mechanical stirring; and add a certain amount of alkaline material to adjust the pH, and obtain the solized slurry after reacting at room temperature;

[0034] (4) aging the slurry prepared in step (3) at a temperature of 50-120° C. for 2-14 hours to form a gel, which is vacuum-dried and pulverized to obtain a coated precursor;

[0035] (5) Calcinate the precursor obtained in step (4) at 600-1100°C for 2-6 hours under an inert atmosphere. After the product drops to room temperature, it is crushed and sieved to obtain a network-like γ-alumina uniformly coated on graphite...

Embodiment 1

[0050] (1) Preparation of coating precursor

[0051] Disperse 600g of graphite in 500ml of deionized water, mechanically stir at 400rpm for 2 hours; then slowly add 100ml of an aqueous solution in which 44.6g of aluminum nitrate nonahydrate is dissolved; then add 29ml of concentrated ammonia water to the system to adjust the pH to 7, and react at room temperature Aluminum sol was formed in 6 hours; finally, the temperature was raised to 80°C for aging reaction for 8 hours to form aluminum gel, and then vacuum-dried at 100°C for 8 hours and mechanically crushed to obtain aluminum hydroxide-coated graphite precursor.

[0052] (2) Preparation of reticular γ-alumina coated modified graphite material

[0053] Put the aluminum hydroxide-coated graphite precursor obtained in (1) in a vacuum tube furnace, raise the temperature to 900°C under a nitrogen atmosphere, the heating rate is 2°C / min, and the holding time is 3h; after the furnace temperature drops to room temperature After pu...

Embodiment 2

[0055] (1) Preparation of coating precursor

[0056] Disperse 600g of graphite in 500ml of deionized water, mechanically stir at 400rpm for 2h; then slowly add 100ml of an aqueous solution in which 89.2g of aluminum nitrate nonahydrate is dissolved; then add 58ml of concentrated ammonia water dropwise to the system to adjust the pH to 7, and react at room temperature Aluminum sol was formed in 6 hours; finally, the temperature was raised to 80°C for aging reaction for 8 hours to form aluminum gel, and then vacuum-dried at 100°C for 8 hours and mechanically crushed to obtain aluminum hydroxide-coated graphite precursor.

[0057] (2) Preparation of reticular γ-alumina coated modified graphite material

[0058] Put the aluminum hydroxide-coated graphite precursor obtained in (1) in a vacuum tube furnace, raise the temperature to 900°C under a nitrogen atmosphere, the heating rate is 2°C / min, and the holding time is 3h; after the furnace temperature drops to room temperature Afte...

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Abstract

The invention relates to the field of negative electrode materials, in particular to a preparation method of a reticular gamma-alumina coated modified graphite negative electrode material. The method comprises the following specific steps: uniformly coating an aluminum salt on the surface of a commercial graphite negative electrode through a sol-gel method; carrying out vacuum drying on the obtained coated precursor; and carrying out high-temperature calcination reaction on the dried product to obtain the reticular gamma-aluminum oxide coated modified graphite material. The invention also provides an application of the netted gamma-alumina coated modified graphite negative electrode. The coated modified graphite material is applied to a lithium ion battery negative electrode. The method is simple in process, mild in condition and low in cost, and the reticular gamma-aluminum oxide coated modified graphite negative electrode material prepared by the method is uniform in surface coating, uniform in particle size distribution, excellent in electrochemical performance, stable in product batch performance and suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to the field of negative electrode materials, in particular to a netted gamma-alumina-coated modified graphite negative electrode material, a preparation method and application thereof. Background technique [0002] In recent years, in order to alleviate climate change and air pollution, and to promote the transformation of the energy system, lithium-ion batteries have been widely used in electric vehicles. However, compared with traditional fuel vehicles, problems such as mileage anxiety and long charging time brought by new energy vehicles have seriously affected consumer experience and hindered market development. Therefore, the fast charging performance of lithium-ion batteries is crucial for next-generation energy storage systems. [0003] For the traditional graphite negative electrode, the characteristics of low working potential (<0.2V) can easily lead to the phenomenon of lithium precipitation, which in turn causes th...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/583H01M4/48H01M10/0525
CPCH01M4/366H01M4/583H01M4/48H01M10/0525H01M2004/027Y02E60/10
Inventor 李叙锋仰永军仰韻霖
Owner DONGGUAN KAIJIN NEW ENERGY TECH
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