Lithium ion battery composite anode material and preparation method thereof

A technology for lithium-ion batteries and negative electrode materials, applied to battery electrodes, circuits, electrical components, etc., can solve the problems of material structure damage, loss of electrical contact, capacity attenuation, etc., and achieve high tap density, high degree of practicality, and method simple and easy effects

Active Publication Date: 2011-11-16
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, Si-based materials undergo severe volume expansion and contraction (volume change rate ~300%) during the intercalation/delithiation cycle, resulting in the destruction of the material structure and mec

Method used

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  • Lithium ion battery composite anode material and preparation method thereof
  • Lithium ion battery composite anode material and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0032] 1) Preparation of nuclear material by spraying once: add thermosetting phenolic resin (according to the content of pyrolytic carbon in the spherical nuclear material after sintering is 15wt%) into an appropriate amount of absolute ethanol, magnetically stir to form a solution with a certain viscosity, and then add nano Silicon powder (Nano-Si, according to the mass ratio of silicon / carbon in the spherical core material after sintering 3:7) and 8wt% polyethylene glycol dispersant, ultrasonically plus mechanical stirring for 1h, and then according to the natural stone in the spherical core material after sintering The ink content is 55wt%, adding natural graphite to disperse for 2 hours, spraying and drying the uniformly dispersed suspension at 170-200°C once to obtain the spherical core material.

[0033]2) Secondary spraying-sintering preparation of silicon-carbon composite negative electrode material: adding pitch (according to the total content of pyrolytic carbon afte...

Embodiment 2

[0036] 1) Prepare the spherical core material by spraying once: add thermosetting phenolic resin (according to the content of pyrolytic carbon in the spherical core material after sintering is 25wt%) into an appropriate amount of absolute ethanol, stir magnetically to form a solution with a certain viscosity, and then add Nano silicon monoxide powder (Nano-SiO, according to the mass ratio of silicon / carbon in the spherical core material after sintering: 1:19) and 0.5wt% polyammonium methacrylate dispersant, ultrasonic plus mechanical stirring for 0.5h, and then according to sintering The content of artificial graphite in the final spherical core material is 70wt%, adding artificial graphite to disperse for 1 hour, spraying and drying the uniformly dispersed suspension at 180-210° C. to obtain the spherical core material.

[0037] 2) Preparation of silicon-carbon composite negative electrode material by secondary spraying and sintering: add pitch (according to the total content ...

Embodiment 3

[0040] 1) Preparation of spherical core material by spraying once: add 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, magnetically stir to form a solution with a certain viscosity, and then add nano-silicon The mixture with silicon monoxide (Nano-Si / SiO, according to the mass ratio of silicon / carbon in the spherical core material after sintering is 4:6) and 10wt% polyethylene glycol dispersant, ultrasonic plus mechanical stirring for 1h, and then according to sintering The content of graphitized mesocarbon microspheres (MCMB) in the spherical core material is 50wt%, and the graphitized mesocarbon microspheres are added to disperse for 2 hours, and the uniformly dispersed suspension is spray-dried once at 120-150°C to obtain a spherical nuclear material.

[0041] 2) Secondary spraying-sintering preparation of silicon-carbon composite negative electrode ...

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Abstract

The invention discloses a lithium ion battery silicon carbon composite anode material and a preparation method thereof. The material is prepared by twice spray drying and once sintering. The preparation method comprises the following steps of: 1) dissolving an organic carbon source in an appropriate amount of solvent, adding a silicon source and a dispersing agent for dispersing suspension uniformly, adding graphitized carbon for dispersing the suspension for a certain period of time, and performing primary spray drying on the uniformly dispersed suspension to obtain a spherical nucleus material; and 2) dissolving the organic carbon source in the appropriate amount of the solvent, adding the prepared spherical nucleus material, dispersing the suspension uniformly, performing secondary spray drying on the uniformly dispersed suspension to obtain powder, transferring the powder into a protective atmosphere for sintering, and performing furnace cooling on the powder to obtain the lithium ion battery composite anode material. The preparation method is simple and practicable and has high practicality; and the prepared silicon carbon composite material has the advantages of large reversible capacity, designable capacity, high cycle performance, high rate capability, 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 lithium ion battery composite negative electrode material and a preparation method thereof. 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. At present, the anode material of commercialized lithium-ion batteries is mainly graphite, but its theoretical capacity is only 372mAh g -1 , can no longer meet the demand for high energy density power supplies in the application field of lithium-ion batteries. Therefore, it is extremely urgent to develop new anode materials for lithium-ion batteries with high specific capacity. [0003] Silicon has the highest theoretical lithium intercalation capacity (~3579mAh·g -1 ) and higher interc...

Claims

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Application Information

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IPC IPC(8): H01M4/1395H01M4/134
CPCY02E60/122Y02E60/12Y02E60/10
Inventor 郭华军赖浚李新海王志兴彭文杰胡启阳张云河
Owner CENT SOUTH UNIV
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