Composite graphite particles for lithium secondary battery and preparation method thereof

A lithium secondary battery and composite graphite technology, which is applied in the direction of battery electrodes, circuits, electrical components, etc., can solve the problems of inability to prevent electrode expansion, low charging and discharging efficiency, and accelerated electrolyte reaction. The preparation method is simple, feasible, Large discharge capacity, good safety effect

Active Publication Date: 2012-07-18
SHANGHAI SHANSHAN TECH CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The problem when the graphite anode material is used with high compaction density is that the reaction with the electrolyte is accelerated due to the cracking of the graphite anode material and the exposure of more surface area to react with the electrolyte, resulting in a decrease in charge and discharge efficiency
[0012] Among the graphite negative electrode materials disclosed in the above-mentioned patent documents, graphite in a flat shape is easy to be oriented in a composite powder and electrode, and when a high compacted density (1.65g / cm 3 Above) when used, cannot prevent electrode expansion, resulting in poor lithium ion mobility of the material, battery capacity below 355mAh / g, and low charge and discharge efficiency

Method used

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  • Composite graphite particles for lithium secondary battery and preparation method thereof
  • Composite graphite particles for lithium secondary battery and preparation method thereof
  • Composite graphite particles for lithium secondary battery and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0046] Petroleum asphalt is crushed to below 0.1mm, and 200kg of spherical natural graphite (D50 is 19.1μm) and 60kg of asphalt powder, graphitization catalyst (SiO 2 ) 16kg in a kneading pot, and kneaded at 160°C for 1 hour. After the kneading was finished, it was pressed into flakes (4mm) in a tablet press, crushed into particles with a particle size of less than 100 μm, and briquetted. Under the protection of nitrogen, carbonize at 1100°C for 2 hours, then cool the reaction product to room temperature, then carry out catalytic graphitization high-temperature treatment at 2800°C for 36 hours, and use a jaw crusher to coarsely crush it to 50-70 Millimeters, and then finely pulverized with an ultra-fine mechanical pulverizer at an impeller speed of 8000 rpm, and the coarse particles were removed with a 250-mesh sieve to obtain composite graphite particles for lithium secondary batteries with a particle size D50 of 17.8 μm. The battery capacity is 362.5mAh / g, and the first-time...

Embodiment 2

[0048] Petroleum asphalt is crushed to less than 0.1mm, and under stirring, alternately add 200kg of spherical natural graphite (D50 is 19.5μm), 20kg of asphalt powder, and 6kg of graphitization catalyst (SiC) into a kneading pot for mixing, kneading at 160°C for 1 hour, kneading After the end, it is pressed into a tablet shape (3 mm) in a tablet machine, crushed into particles with a particle size of less than 100 μm, and pressed into a block. Under the protection of nitrogen, carbonize at 800°C for 6 hours, then cool the reaction product to room temperature, then carry out high-temperature catalytic graphitization at 3000°C for 48 hours, and use a jaw crusher to coarsely crush it to 50-70 Millimeters, and then finely pulverize with an impeller speed of 8000 rpm with an ultra-fine mechanical pulverizer, remove coarse particles with a 250-mesh sieve, and obtain composite graphite particles with a particle size D50 of 18.3 μm for lithium secondary batteries, and its half-cell T...

Embodiment 3

[0050] Coal tar pitch is crushed to below 0.1mm, and 200kg of spherical natural graphite (D50 is 20.1μm) and 40kg of pitch powder, graphitization catalyst (SiO 2 ) 10kg in a kneading pot, and kneaded at 160°C for 1 hour. After the kneading was finished, it was pressed into a tablet shape (5 mm) in a tablet machine, crushed into particles with a particle size of less than 100 μm, and briquetted. Under the protection of nitrogen, carbonize at 1500°C for 3 hours, then cool the reaction product to room temperature, then carry out high-temperature catalytic graphitization at 3200°C for 48 hours, and use a jaw crusher to coarsely crush it to 50-70 Millimeters, and then finely pulverize with an impeller speed of 8000 rpm with an ultra-fine mechanical pulverizer, remove coarse particles with a 250-mesh sieve, and obtain composite graphite particles with a particle size D50 of 17.4 μm for lithium secondary batteries, and its half-cell The capacity is 365.0mAh / g, and the first-time effi...

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Abstract

The invention relates to a preparation method for composite graphite particles for a lithium secondary battery. The method comprises the following steps: 1, heating and kneading spherical natural graphite particles, adhesive capable of being graphitization, and graphitized catalyst to form a kneaded thing; 2, pressing the kneaded thing into block to form a formed kneaded thing; 3, under the protection of an inert gas, carbonizing the formed kneaded thing at the temperature of 800-1,500 DEG C, and cooling the kneaded thing to room temperature; 4, under the protection of the inert gas, allowing the formed kneaded thing to be subjected to catalysis and graphitization high-temperature processing at the temperature of 2,800-3,200 DEG C; and 5, performing classifying or screening after the kneaded thing is smashed. The invention further relates to composite graphite particles for the lithium secondary battery prepared by the method. The composite graphite particles have higher compacted density, large discharge capacity, good circulation performance, good electrochemistry performance, better high-current charge-discharge performance, and better safety, discharge platform availability and higher platform retention rate.

Description

technical field [0001] The invention relates to a composite graphite particle for a lithium secondary battery and a preparation method thereof. Background technique [0002] In recent years, with the miniaturization of electronic devices, there has been an increasing need for a secondary battery with a larger capacity. Of particular interest are lithium-ion batteries, which have a higher energy density than nickel-cadmium or nickel-metal hydride batteries. Although extensive research has been conducted on increasing the battery capacity, further increases in battery capacity are required as the requirements for battery performance increase. [0003] As negative electrode materials for lithium ion batteries, granular materials such as metals or graphite have been studied. With the increase of battery capacity, it is especially necessary to use higher electrode density (such as 1.7g / cm 3 or higher than 1.7g / cm 3 ) The negative electrode material used. [0004] Natural gra...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/38
CPCY02E60/12Y02E60/10
Inventor 谢秋生杜辉玉吴志红李杰李辉
Owner SHANGHAI SHANSHAN TECH CO LTD
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