Meg/si/c composite negative electrode material for lithium ion battery and preparation method thereof

A lithium-ion battery and negative electrode material technology, applied in battery electrodes, nanotechnology for materials and surface science, negative electrodes, etc., can solve the problems of poor electrode cycle stability, low lithium ion intercalation and extraction rates, and low capacity , to achieve the effects of high-current charging and discharging, increasing lithium intercalation/detachment channels, and increasing specific surface area

Active Publication Date: 2021-02-02
ZIGONG DONGXIN CARBON CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a MEG / Si / C composite negative electrode material for lithium-ion batteries, which solves the problems of low capacity, poor cycle stability of electrodes and lithium ion intercalation and Problems such as low exit rate

Method used

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  • Meg/si/c composite negative electrode material for lithium ion battery and preparation method thereof
  • Meg/si/c composite negative electrode material for lithium ion battery and preparation method thereof
  • Meg/si/c composite negative electrode material for lithium ion battery and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0032]1) At room temperature, after weighing 20g of artificial flake graphite, 45mL of concentrated sulfuric acid (98%) and 35mL of hydrogen peroxide (30%) in a three-necked flask, place it in an ice-water bath for chemical oxidation intercalation reaction for 4 h , and then the solid was separated by filtration, and the solid was washed with deionized water until the supernatant was neutral (pH=7). Grind the filter cake into fine powder and set aside;

[0033] 2) Put the fine powder prepared in step 1) in a tube furnace, raise the temperature in the air to 400°C at 2K / min, keep it warm for 5 hours, and then cool it under nitrogen protection and place it at room temperature to obtain micro-expanded graphite;

[0034] 3) Accurately weigh 5g of micro-expanded graphite, 0.25g of nano silicon powder and 0.158g of PVP and place them in a ball mill at 400r / min for 4h, then add 1.99g of glucose into the ball mill tank, and mill at a speed of 400r / min for 4h. get the mixture;

[003...

Embodiment 2

[0037] 1) At room temperature, after weighing 20g of microcrystalline graphite, 45mL of concentrated nitric acid (98%) and 35mL of potassium permanganate (30%) in a three-neck flask, place it in an ice-water bath for chemical oxidation intercalation reaction for 4 h After that, the solid was separated by filtration, and the solid was washed with deionized water until the supernatant was neutral (pH=7), and then the solid was dried in a vacuum oven at 110 °C for 12 h, and the Grind the filter cake into fine powder and set aside;

[0038] 2) Put the fine powder prepared in step 1) in a tube furnace, raise the temperature in the air to 400°C at 2K / min, keep it warm for 5 hours, and then cool it under nitrogen protection and place it at room temperature to obtain micro-expanded graphite;

[0039] 3) Accurately weigh 5g of micro-expanded graphite, 0.5g of nano silicon powder and 0.165g of sodium lauryl sulfate and place them in a planetary ball mill at 500r / min for 4 hours, then ad...

Embodiment 3

[0042] 1) At room temperature, weigh 20g of secondary granulated graphite, 45mL of concentrated sulfuric acid (98%) and 35mL of hydrogen peroxide (30%) in a three-necked flask, and place it in an ice-water bath for chemical oxidation intercalation reaction4 After h, the solid was separated by filtration, washed with deionized water until the supernatant was neutral (pH=7), and then dried in a vacuum oven at 110°C for 12 h, and ground with agate Bowl to grind the filter cake into fine powder, set aside;

[0043] 2) Put the fine powder prepared in step 1) in a tube furnace, raise the temperature in the air to 400°C at 2K / min, keep it warm for 5 hours, and then cool it under nitrogen protection and place it at room temperature to obtain micro-expanded graphite;

[0044] 3) Accurately weigh 5g of micro-expanded graphite, 0.75g of nano silicon powder and 0.173g of PVP and place them in a planetary ball mill at 500r / min for 4h, then add 2.18g of glucose into the ball milling tank, a...

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Abstract

The invention discloses a MEG / Si / C composite negative electrode material for lithium ion batteries and a preparation method thereof. The composite negative electrode material comprises the following components in mass fractions: 2-20% of nano silicon powder, 1%-3% of surfactant % and carbon source 10~30%, and the balance is micro-expanded graphite. Micro-expanded graphite was prepared by chemical oxidation intercalation method and low-temperature thermal expansion technology, and then micro-expanded graphite / silicon / carbon (MEG / Si / C) composite negative electrode materials for lithium-ion batteries were prepared by mechanical ball milling and high-temperature carbonization. The invention not only effectively relieves the volume expansion and contraction effect of graphite intercalation / delithiation, but also increases lithium intercalation / delithiation channels, which is beneficial to high-current charging and discharging, and ensures proper volume energy density and coulombic efficiency of the negative electrode material. The specific capacity of the first discharge can reach 857.9 mAh / g, which has large specific capacity, good rate performance and stable electrode cycle. The preparation method of the invention has simple process flow, simple and easy-to-obtain raw materials, low cost, and is easy for large-scale production.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a MEG / Si / C composite negative electrode material for lithium ion batteries and a preparation method thereof. Background technique [0002] Because of its high energy density, high power density, long cycle life, no memory effect, safety and reliability, and environmental friendliness, lithium-ion batteries are considered to be the most ideal tool for energy storage and conversion. They have great potential in the fields of energy storage and electric vehicles. It has broad application prospects and has become one of the main research hotspots in the new energy industry. However, at present, the internal impedance of lithium-ion batteries is high, the operating voltage varies greatly, and the cost is high. Special protection circuits are necessary, and the power density and charge-discharge specific capacity of lithium-ion batteries used in the field of p...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/583H01M10/0525B82Y30/00
CPCB82Y30/00H01M4/364H01M4/386H01M4/583H01M10/0525H01M2004/027Y02E60/10
Inventor 陈建刘平李琳龚勇彭川赖世毅
Owner ZIGONG DONGXIN CARBON CO LTD
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