Apple-shaped embedded silicon carbon negative electrode material and preparation method thereof

A negative electrode material, silicon carbon material technology, applied in the field of apple-shaped embedded silicon carbon negative electrode material and its preparation, can solve the problems of affecting application, material pulverization and falling off, cycle performance degradation, etc.

Active Publication Date: 2018-08-14
TIANJIN B&M SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, silicon will produce a huge volume expansion (>300%) during the process of absorbing lithium, which will cause the

Method used

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  • Apple-shaped embedded silicon carbon negative electrode material and preparation method thereof
  • Apple-shaped embedded silicon carbon negative electrode material and preparation method thereof
  • Apple-shaped embedded silicon carbon negative electrode material and preparation method thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0025] A method for preparing an apple-shaped embedded silicon-carbon negative electrode material, comprising the steps of:

[0026] 1) Add natural graphite, absolute ethanol and polyethylene glycol accounting for 1% of the graphite mass into a sand mill for ball milling until the particle size is D 50 =1 μm, to obtain slurry I;

[0027] 2) Slurry I is spray-dried in a nitrogen atmosphere with a pressure spray drying unit. During spray drying, the inlet temperature is 210°C and the pressure is 0.7Mpa to obtain material I. The shape of material I is a cylinder with rounded edges shape;

[0028] 3) The material I was roasted once at 450°C in a nitrogen atmosphere for 12 hours to obtain the material II;

[0029] 4) Combine material II, absolute ethanol, polyethylene glycol and particle size D 50 The silicon powder of =90nm is added into the stirring ball mill for stirring, the quality of the silicon powder is 5% of the quality of the material II, the quality of polyethylene gl...

Embodiment 2

[0034] A method for preparing an apple-shaped embedded silicon-carbon negative electrode material, comprising the steps of:

[0035] 1) Add artificial graphite, absolute ethanol and polyethylene glycol accounting for 1% of the graphite mass into a sand mill for ball milling until the particle size is D 50 =1 μm, to obtain slurry I;

[0036] 2) Slurry I is spray-dried in a nitrogen atmosphere with a pressure spray drying unit. During spray drying, the inlet temperature is 160°C and the pressure is 0.4Mpa to obtain material I. The shape of material I is a cylinder with rounded edges shape;

[0037] 3) The material I was roasted once at 700° C. in a nitrogen atmosphere, and the roasting time was 6 hours to obtain the material II;

[0038] 4) Combine material II, absolute ethanol, polyethylene glycol and particle size D 50 The silicon powder of =90nm is added into the stirring ball mill for stirring, the quality of the silicon powder is 5% of the quality of the material II, the...

Embodiment 3

[0043] A method for preparing an apple-shaped embedded silicon-carbon negative electrode material, comprising the steps of:

[0044] 1) Add artificial graphite, absolute ethanol and polyvinyl alcohol accounting for 3% of the graphite mass into a sand mill for ball milling until the particle size after ball milling is D 50 =0.8 μm, to obtain slurry I;

[0045] 2) Slurry I is spray-dried in an argon atmosphere with a pressure spray drying unit. During spray drying, the inlet temperature is 200°C and the pressure is 0.7Mpa to obtain material I. The shape of material I is a circle with rounded edges Cylindrical;

[0046] 3) The material I was roasted once at 700°C in an argon atmosphere for 12 hours to obtain material II;

[0047] 4) Combine material II, absolute ethanol, polyvinyl alcohol and particle size D 50 =90nm silicon powder is added into the stirring ball mill for stirring, the quality of the silicon powder is 10% of the quality of the material II, the quality of polyv...

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Abstract

The invention discloses an apple-shaped embedded silicon carbon negative electrode material and a preparation method thereof, wherein the silicon carbon negative electrode material is orderly composedof a core part, a middle part and an external layer from inside to outside; the core part is a micron-level carbon coated silicon carbon material, the middle part is a micron-level graphite material,and the external layer is a submicron-level carbon coated silicon carbon material; the middle part is cylindric and has a rounded edge, the middle part is filled with the core part, and sunken partsare formed at two ends of the middle part; and the external layer covers a surface of the middle part. The preparation method comprises the following steps: obtaining a hollow apple-shaped graphite material by executing spray drying, carbonization and other means on the graphite, then, filling the inside of a hollow structure with a silicon carbon composite material, meanwhile, covering the external surface with the silicon carbon composite material; then, obtaining a target product through high temperature carbonization. With the carbon coated silicon carbon material in the apple-shaped embedded silicon carbon negative electrode material, specific capacity of the product is improved, and the graphite in the middle part not only can improve electrical conductivity of the silicon carbon material, but also can limit volume expansion of the silicon.

Description

technical field [0001] The invention relates to the field of negative electrode materials for lithium-ion secondary batteries, in particular to an apple-shaped embedded silicon-carbon negative electrode material and a preparation method thereof. Background technique [0002] Power batteries are the core part of new energy vehicles, among which lithium-ion batteries have obvious advantages in terms of cost and energy density, which will greatly improve the economy and convenience of use of new energy vehicles. The positive electrode material in the lithium-ion battery system is the decisive factor . New energy vehicles should be fully or partially driven by electricity. Compared with traditional fuel vehicles, they can reduce fuel consumption. However, at present, the savings in fuel consumption during the entire life cycle of new energy vehicles cannot offset the increased costs. If the cruising range of a pure electric vehicle reaches 400 kilometers, and the cost of the ba...

Claims

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Application Information

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IPC IPC(8): H01M4/36H01M4/583H01M4/62H01M10/0525H01M4/38
CPCH01M4/362H01M4/386H01M4/583H01M4/62H01M10/0525Y02E60/10
Inventor 徐宁宋英杰伏萍萍马倩倩吴孟涛
Owner TIANJIN B&M SCI & TECH
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