Silicon/graphene laminar composite material for lithium ion battery cathode and preparation method thereof

A technology for lithium ion batteries and composite materials, applied in the field of silicon/graphene composite materials and their preparation, can solve problems such as unsatisfactory cycle stability, achieve good electrochemical activity and cycle stability, buffer volume expansion, and preparation technology simple effect

Active Publication Date: 2011-05-18
深圳清研紫光科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The composite material prepared by Harold H. Kung et al. by directly combining silicon nanoparticles with graphene can reach ~2200mAh / g, but the cycle stability is not ideal, and the capacity drops to ~1500mAh / g after 200 cycles [Jeong K. Lee, Kurt B. Smith, Cary M. Hayner et al. Chem. Commun., 2010, 46, 2025-2027.]

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] Dissolve 0.06g of dodecyltrimethylammonium bromide in 75mL of THF, and then add 0.68g of anhydrous SiCl 4 Until dissolved, ultrasonically disperse 0.1g of graphite oxide in 75mL of tetrahydrofuran for 2h and add it into the solution, dissolve 0.12g of sodium naphthalene in 25mL of tetrahydrofuran, mix the above prepared solution into a 250mL reactor, and evacuate to 10Pa to Raise the temperature to 380°C at a heating rate of 5°C / min, and react for 24 hours. After the reactor was cooled to room temperature, the product was separated by filtration, and then washed three times with 50 mL of hexane and deionized water, until no raw materials and by-products could be detected in the washing liquid. After drying at room temperature for 10 hours, the product was placed in a furnace protected by an argon inert atmosphere, and the temperature was raised to 600° C. at a rate of 5° C. / min for 1 hour to obtain a silicon / graphene composite material.

Embodiment 2

[0013] Dissolve 0.006g of dodecyltrimethylammonium bromide in 75mL of THF, and then add 0.068g of anhydrous SiCl 4 Until dissolved, ultrasonically disperse 0.1g of graphite oxide in 75mL of tetrahydrofuran for 2h and add it into the solution, dissolve 0.012g of sodium naphthalene in 25mL of tetrahydrofuran, mix the above prepared solution into a 250mL reactor, and evacuate to 10Pa to Raise the temperature to 380°C at a heating rate of 5°C / min, and react for 24 hours. After the reactor was cooled to room temperature, the product was separated by filtration, and then washed three times with 50 mL of hexane and deionized water, until no raw materials and by-products could be detected in the washing liquid. After drying at room temperature for 10 hours, the product was placed in a furnace protected by an argon inert atmosphere, and the temperature was raised to 600° C. at a rate of 5° C. / min for 1 hour to obtain a silicon / graphene composite material.

Embodiment 3

[0015] The process and conditions of this embodiment are the same as that of Embodiment 1, except that the degree of vacuum is changed: from 10Pa to 1000Pa.

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PUM

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Abstract

The invention relates to a preparation method of a silicon/graphene laminar composite material for lithium ion battery cathode. The composite material adopts a laminar sandwich structure, silicon nano-particles are dispersed on each lamina of the grapheme, the laminas of the grapheme are separated from one another by the silicon nano-particles and the edges of the laminas are in lapped joint so as to constitute a laminar conductive network structure. The preparation method thereof comprises the steps of: formulating anhydrous silicon tetrachloride, surface active agent, sodium naphthalene and graphite oxide to tetrahydrofuran solution, adding the tetrahydrofuran solution into a reactor for reaction in vacuum at the temperature ranging from 380 to 400 DEG C, filtering the reactant to result in the product, and then washing, drying and heating the product to obtain the silicon/grapheme composite material. The preparation method of the invention has the advantages of simple preparation process and great easiness for industrial production; and the silicon/graphene laminar composite material prepared according to the method includes excellent conductivity, power performance, electrochemical activity and cycle stability, and is particularly suitable for manufacturing lithium ion battery cathode.

Description

technical field [0001] The invention relates to a silicon / graphene composite material for a negative electrode of a lithium ion battery and a preparation method thereof, belonging to the negative electrode material of a lithium ion battery and a preparation technology thereof. Background technique [0002] In today's world, fossil fuels are becoming increasingly depleted of traditional energy sources, and the environmental pollution caused by the burning of fossil fuels is also becoming more and more serious. The harmonious and sustainable development of energy, resources, environment and human society has become the focus of social attention, and the pursuit of renewable and clean energy and the harmonious development of human and environment have gradually become the theme of the times. In the process of new energy development, the green and efficient storage and transfer of energy has become a key issue. Lithium-ion batteries with high power density and high energy densi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/38H01M4/1395
CPCY02E60/12Y02E60/122Y02E60/10
Inventor 杨全红魏伟苏方远陈学成吕伟
Owner 深圳清研紫光科技有限公司
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