Si/CNT/graphite@C composite silicon-carbon negative electrode material as well as preparation and application thereof

A negative electrode material, graphite technology, applied in carbon preparation/purification, nanotechnology for materials and surface science, silicon, etc., can solve problems such as unsatisfactory chemical properties and unsatisfactory performance

Active Publication Date: 2020-12-04
湖南宸宇富基新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In order to solve the technical problem of the unsatisfactory electrochemical performance of existing silicon-carbon materials, especially the unsatisfactory fast charging performance, the first purpose of the present invention is to provide a Si / CNT / graphite@C composite silicon with a new morphology Carbon negative electrode material (the present invention is also referred to as negative electrode active material or silicon-carbon composite material), aims to improve the capacity, rate performance, cycle performance and service life of lithium-ion batteries, especially to improve the stability of fast charging

Method used

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  • Si/CNT/graphite@C composite silicon-carbon negative electrode material as well as preparation and application thereof
  • Si/CNT/graphite@C composite silicon-carbon negative electrode material as well as preparation and application thereof
  • Si/CNT/graphite@C composite silicon-carbon negative electrode material as well as preparation and application thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0085] ①Take 0.05gAgNO 3 Dissolve in 50ml of HF solution with a concentration of 10M, add 1g of nano-silicon particles into the mixture and stir for 0.5h, then add 10ml of hydrogen peroxide (30%H 2 o 2 aqueous solution), continue to stir for 1 hour, filter with suction, wash, and dry in an oven at 120°C;

[0086] ②Add the obtained porous silicon (0.8g) and 0.05g of cobalt chloride to 20ml of water and 10ml of ethanol, stir and dissolve, then dry in an oven at 80°C;

[0087] ③The obtained material (0.85g), spherical graphite (0.5g), polyvinylidene fluoride (0.05g), and 0.2g pitch are placed in a mixer and mixed evenly, and the mixed material is sent into a kneader, To granulate;

[0088] ④ Place the material obtained in the previous step in a nitrogen atmosphere furnace, vacuumize, keep the pressure in the furnace at 200Pa, and perform heat treatment. The heat treatment temperature is 750°C, and the holding time is 2h;

[0089] ⑤ Place the material obtained in the previous ...

Embodiment 2

[0094] ①Take 0.05gAgNO 3 Dissolve in 50ml of HF solution with a concentration of 10M, add 1g of nano-silicon particles into the mixture and stir for 0.5h, then add 10ml of hydrogen peroxide (30%H 2 o 2 aqueous solution), continue to stir for 1 hour, filter with suction, wash, and dry in an oven at 120°C;

[0095] ②Add the obtained porous silicon (0.75g; porosity 22%) and 0.1g ferric nitrate to 20ml water, stir and dissolve, then dry in an oven at 80°C;

[0096] ③Place the obtained material (0.85g), petroleum coke (2g), polypropylene (0.05g), and 0.2g phenolic resin in a mixer to mix evenly, and send the mixed material into a kneader for granulation ;

[0097] ④ Place the material obtained in the previous step in a nitrogen atmosphere furnace, vacuumize, keep the pressure in the furnace at 500Pa, and perform heat treatment. The heat treatment temperature is 800°C, and the holding time is 3h;

[0098] ⑤ Place the material obtained in the previous step in a hydrogen atmospher...

Embodiment 3

[0103] ①Take 0.05gAgNO 3 Dissolve in 50ml of HF solution with a concentration of 10M, add 1g of nano-silicon particles into the mixture and stir for 0.5h, then add 10ml of hydrogen peroxide (30%H 2 o 2 aqueous solution), continue to stir for 1h, filter with suction, wash, and dry in an oven at 120°C

[0104] ②Add the obtained porous silicon (0.85g) and 0.1g of nickel oxalate into 20ml of water, stir and dissolve, then dry in an oven at 80°C;

[0105] ③Put the obtained material, natural graphite (2g), sodium alginate (0.05g), and 0.2g glucose in a mixer for uniform mixing, and send the mixed material into a kneader for granulation;

[0106] ④ Place the material obtained in the previous step in a nitrogen atmosphere furnace, vacuumize, keep the pressure in the furnace at 200Pa, and perform heat treatment. The heat treatment temperature is 600°C, and the holding time is 4h;

[0107] ⑤ Place the material obtained in the previous step in a hydrogen atmosphere furnace, and conduc...

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Abstract

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly discloses a Si/CNT/graphite@C composite silicon-carbon negative electrode material, which comprises an inner core and pyrolytic carbon coating the surface of the inner core, the inner core is secondary particles formed by aggregation of Si@CNT primary particles and graphite; and the Si@CNT primary particles comprise porous silicon and carbon nanotubes compounded on the surface of the porous silicon in situ. In addition, the invention also discloses a preparation method of the material. The silicon-carbon composite material prepared by the invention can be used for a fast-charging lithium ion battery, has the advantages of high rate capability, high cycling stability, long service life and controllable specific capacity, and is simple in preparation process, wide in raw material source and suitable for large-scale production.

Description

technical field [0001] The invention relates to a silicon-carbon composite negative electrode for a lithium ion battery and a preparation method thereof, in particular to a fast-charging silicon-carbon composite negative electrode material and a preparation method thereof. The invention belongs to the field of composite material and electrochemical technology. Background technique [0002] In order to solve various negative problems caused by the current burning of fossil energy, it is imminent to develop new green renewable energy. Lithium-ion battery is currently the most promising green rechargeable chemical power source. Lithium-ion batteries have significant advantages over other secondary battery systems and are widely used in portable electronic devices. With the increasing demand for pure electric vehicles and hybrid battery vehicles, the energy density and functional density of lithium-ion batteries are increasingly demanding. At present, limited by the low theor...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/587H01M4/62H01M10/0525C01B32/05C01B32/162C01B32/205C01B33/02B82Y30/00B82Y40/00
CPCB82Y30/00B82Y40/00C01B33/02C01B2202/22C01B32/05C01B32/162C01B32/205H01M4/362H01M4/386H01M4/587H01M4/625H01M10/0525Y02E60/10
Inventor 周昊宸周向清王鹏周进辉
Owner 湖南宸宇富基新能源科技有限公司
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