Preparation method for composite cathode material of lithium ion battery

A negative electrode material, silicon-carbon composite technology, applied in the direction of battery electrodes, circuits, electrical components, etc., can solve the problems of electrode cycle performance degradation, limited commercial application, material structure damage, etc., to achieve capacity design, cycle performance and large Good current discharge capacity and high tap density

Active Publication Date: 2012-08-22
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the silicon negative electrode undergoes severe volume expansion and contraction during the lithium intercalation and deintercalation cycles, resulting in the destruction of the material structure and mechanical crushing, which leads to the degradation of the electrode cycle performance and limits its commercial application.

Method used

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  • Preparation method for composite cathode material of lithium ion battery
  • Preparation method for composite cathode material of lithium ion battery
  • Preparation method for composite cathode material of lithium ion battery

Examples

Experimental program
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Effect test

Embodiment 1

[0033] Petroleum pitch was used as raw material, pretreated in a nitrogen atmosphere at 400°C for 10 hours to remove low-temperature volatile organic compounds, and the pretreated coal tar pitch was used as the second type of binder. The first type of binder phenolic resin (according to the 5wt% addition of pyrolytic carbon content in the spherical core material after sintering) is added to an appropriate amount of deionized water, magnetically stirred to form a viscous solution, and then add nano silicon powder (Nano-Si , according to the mass ratio of silicon / carbon in the spherical core material after sintering: 1:19) the second type of binder (petroleum pitch after pretreatment, added according to the content of coking carbon in the material after sintering is 5wt%) and 10wt% polypropylene Amide dispersant, ball milling for 5 hours, ultrasonic plus mechanical stirring and dispersion for 1 hour, and then according to the content of natural graphite in the spherical core mate...

Embodiment 2

[0036]Coal tar pitch is used as raw material, pretreated in an argon atmosphere at 400°C for 1 hour to remove low-temperature volatile organic compounds, and the pretreated coal tar pitch is used as the second type of binder. Add the first type of binder polyvinyl alcohol-124 (according to the content of pyrolytic carbon in the composite material after sintering is 25wt%) into an appropriate amount of absolute ethanol, stir magnetically to form a viscous solution, and then add nano silicon monoxide powder (Nano-SiO, according to the mass ratio of silicon / carbon in the spherical core material after sintering: 1:9), the second type of binder (coal tar pitch after pretreatment, according to the content of coking carbon in the spherical core material after sintering is 10wt%) Add) and 0.5wt% polyammonium methacrylate dispersant, ball mill for 1h, ultrasonically add mechanical stirring and disperse for 0.5h, then press the content of artificial graphite in the spherical core materia...

Embodiment 3

[0039] Coal tar pitch is used as raw material, pretreated in a nitrogen atmosphere at 260°C for 20 hours to remove low-temperature volatile organic compounds, and the pretreated coal tar pitch is used as the second type of binder. Add the first type of binder urea-formaldehyde resin (according to the content of pyrolytic carbon in the spherical core material after sintering is 10wt%) into an appropriate amount of deionized water, stir magnetically to form a viscous solution, and then add the mixture of nano-silicon and silicon monoxide (Nano-Si / SiO=1:1, according to the mass ratio of silicon / carbon in the spherical material after sintering is 3:17) the second type of binder (coal tar pitch after pretreatment, according to the coking carbon content in the spherical core material after sintering) Add 40wt% polyethylene glycol dispersant) and 5wt% polyethylene glycol dispersant, ultrasonically add mechanical stirring to disperse for 1h, and then add the graphitized intermediate D...

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Abstract

The invention discloses a preparation method for a composite cathode material of a lithium ion battery by means of spray drying pyrolysis treatment. The preparation method includes the steps: dissolving a first type of binder organic carbon source into solvent of a proper quantity, adding a silicon source, a second type of binder and a dispersing agent, dispersing uniformly, adding graphite, dispersing for a certain time, subjecting uniformly dispersed suspension to spray drying, and using the first type of binder organic carbon source to bond the silicon source, the graphite and the second type of binder particles into spherical or spherical-like forms to obtain a composite precursor; and transferring the precursor into a shielding atmosphere for sintering, heating the second type of binder to a certain temperature to be melted into a liquid crystal state, bonding the particle silicon source and the graphite into cores, subjecting the organic carbon source to pyrolysis at the high temperature to form a coating, and furnace cooling to obtain the carbon-silicon composite cathode material of the lithium ion battery. The preparation method is simple, easy in implementation and high in practicality. The carbon-silicon composite prepared by the method has the advantages of high reversible capacity, designable capacity, high circulating performance and high-current discharging performance, high tap density and the like.

Description

technical field [0001] The invention belongs to the field of lithium ion battery materials and preparation methods thereof, and relates to a preparation method of lithium ion battery composite negative electrode materials. Background technique [0002] Lithium-ion batteries are widely used in various portable electronic devices and electric vehicles due to their advantages such as large specific energy, high working voltage, low self-discharge rate, small size, and light weight. The current commercial lithium-ion battery anode material is mainly graphite, but its theoretical capacity is only 372mAh g -1 , high rate charge and discharge capacity is low, poor low temperature performance and other reasons, can no longer meet the demand for high energy density power supply in the field of lithium ion battery applications. Therefore, it is extremely urgent to develop new anode materials for lithium-ion batteries with high specific capacity. [0003] Si-based materials have the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/38
CPCY02E60/10
Inventor 郭华军黄思林王志兴李新海彭文杰胡启阳张云河甘雷
Owner CENT SOUTH UNIV
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