Silicon-based negative electrode material with multi-buffer structure, and preparation method thereof

A silicon-based negative electrode material and buffer structure technology, applied in the field of material processing, can solve the problems of low initial charge and discharge efficiency, unstable material performance, poor cycle life of composite materials, etc., to inhibit polymerization and peeling, improve electrochemical performance, The effect of good cycle performance

Inactive Publication Date: 2018-01-23
常州市宇科不绣钢有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] The technical problem to be solved by the present invention: In view of the huge volume change of silicon in the lithium intercalation process, which seriously damages the stability of the electrode, and the electrical conductivity is poor, the cycle life of the composite material is poor, the initial charge and discharge efficiency is low, and the complicated The preparation process makes it difficult to control many influencing factors, leading to the problem of unstable material performance. A silicon-based negative electrode material with multiple buffer structures and its preparation method are provided.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0031] Take 5g of 325 mesh sieve micron silicon and add it to a stainless steel ball mill jar, and ball mill it for 10 hours under an argon atmosphere to obtain nanometer silicon powder.

[0032] Add 34g of tetrabutyl titanate into 300mL of 80% ethanol solution, stir at 300r / min for 10min, then add 2.8g of nano-silica powder, disperse with 300W ultrasonic wave for 30min, put it into a spray dryer and spray dry it. The air inlet temperature is 250°C, and the air outlet temperature is 110°C to obtain titanium dioxide-coated silicon. Take 3.5g of titanium dioxide-coated silicon, add it to 150g of 1% sucrose / ethanol solution, disperse it with 300W ultrasonic wave for 20min, and turn to Put it into a rotary evaporator, evaporate to dryness at 80°C to obtain the precursor, put the precursor in a tube furnace, and raise the temperature to 400°C at a heating rate of 5°C / min under an argon atmosphere, and keep it warm for 2 hours. Raise the temperature to 700°C at a heating rate of 5°C...

example 2

[0034] Take 8g of 325 mesh sieve micron silicon and add it to a stainless steel ball milling tank, and ball mill it under an argon atmosphere for 11 hours to obtain nanometer silicon powder. Take 51g of tetrabutyl titanate and add it to 450mL of 80% ethanol solution, and stir at 350r / min for 12min. Then add 4.2g of nano-silica powder, disperse it with 300W ultrasonic wave for 35min, put it into a spray dryer and spray dry it. Add 280g of silicon into a 1% sucrose / ethanol solution, disperse it with a 300W ultrasonic wave for 25 minutes, then transfer it to a rotary evaporator, and evaporate it to dryness at 85°C to obtain a precursor, which is placed in a tube furnace In an argon atmosphere, the temperature was raised to 450°C at a heating rate of 8°C / min, the temperature was raised to 750°C at a heating rate of 8°C / min for 2 hours, and the temperature was raised to 750°C at a heating rate of 8°C / min. 4h, multi-buffered silicon-based anode material.

example 3

[0036]Take 10g of 325-mesh sieve micron silicon and add it to a stainless steel ball mill jar, and ball mill it under an argon atmosphere for 12 hours to obtain nano-silicon powder. Take 68g of tetrabutyl titanate and add it to 600mL of 80% ethanol solution, and stir at 400r / min for 15min. Then add 5.6g of nano-silica powder, disperse it with 300W ultrasonic wave for 40min, put it into a spray dryer and spray dry, control the inlet air temperature to 270°C, and the outlet air temperature to 120°C to obtain titanium dioxide-coated silicon, take 7.0g titanium dioxide-coated Cover silicon, add 300g mass fraction of 1% sucrose / ethanol solution, disperse with 300W ultrasonic wave for 30min, then transfer to rotary evaporator, and evaporate to dryness at 90°C to obtain precursor, which is placed in tube In the furnace, in an argon atmosphere, the temperature was raised to 500°C at a heating rate of 10°C / min, and then the temperature was raised to 800°C at a heating rate of 10°C / min f...

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Abstract

The invention relates to a silicon-based negative electrode material with a multi-buffer structure, and a preparation method thereof, and belongs to the technical field of material processing. According to the silicon-based negative electrode material provided by the invention, a nanometer titanium dioxide layer is coated on the surface of nanometer silicon powder, the stable structure of the nanometer titanium dioxide is used as a buffer layer of volume change of silicon particles in a lithium embedding and removing process to successfully inhibit the polymerization and peeling of the siliconparticles, and the electrochemical performance of the electrode material is also improved, then an amorphous carbon layer is coated to prepare a silicon-based electrode material with a double-layer coating structure, the volume expansion of the core of the activated silica is effectively buffered by the double-layer coating structure in a charge and discharge process, the stability of an electrode / electrolyte interface and a surface SEI film is maintained, and thus the composite material exhibits good cycle performance.

Description

technical field [0001] The invention relates to a silicon-based negative electrode material with a multiple buffer structure and a preparation method thereof, belonging to the technical field of material processing. Background technique [0002] Coal, natural gas, petroleum, etc. are traditional energy sources that are widely used at present, promoting the development of industry and the whole society. However, with the rapid development of the economy, human beings have increased the consumption of fossil fuels, leading to further deterioration of environmental pollution, which has seriously affected the survival of human beings. Fossil fuels are carbon-based energy substances. The massive combustion of fossil fuels will inevitably produce a large amount of carbon dioxide. As a greenhouse gas, carbon dioxide will definitely increase the global temperature, resulting in rising sea levels, erratic weather, and the gradual decline in the range of human activities. reduce. Ot...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/134H01M4/36
CPCY02E60/10
Inventor 史琴娟王之霖陈倩
Owner 常州市宇科不绣钢有限公司
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