Core-shell type composite negative electrode material as well as preparation method and application thereof

A negative electrode material, core-shell technology, applied in the field of lithium-ion battery negative electrode material application, core-shell high-capacity long-cycle composite negative electrode material, can solve problems such as limited application, limited performance improvement, and difficulty in meeting practical application needs, etc. To achieve good bonding performance, improve the composite effect, enhance the effect of electrical conductivity

Pending Publication Date: 2020-11-17
BTR NEW MATERIAL GRP CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The carbon-coated silicon / graphite composite prepared by this method has good reversible specific capacity, good rate performance and cycle stability, but its performance improvement is limited, which is difficult to meet the needs of practical applications.
[0004] Although the cycle, expansion and rate performance of silicon-based materials can be improved to a certain extent by means of nano-silicon-based materials, graphite composites, and carbon coatings, the shortcomings of silicon-based materials are still relatively obvious, and their applications are limited.

Method used

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  • Core-shell type composite negative electrode material as well as preparation method and application thereof
  • Core-shell type composite negative electrode material as well as preparation method and application thereof
  • Core-shell type composite negative electrode material as well as preparation method and application thereof

Examples

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Effect test

Embodiment 1

[0076] This embodiment provides a core-shell composite negative electrode material and a preparation method thereof, the method comprising the following steps:

[0077] (1) Flake silicon with a median particle size of 80 nm and an aspect ratio of 8, and flaky SiO with a median particle size of 400 nm and an aspect ratio of 3 0.98 Carry out kneading molding with a median particle size of 5 μm and flake natural graphite with an aspect ratio of 10 in a mass ratio of 30:30:40 to obtain precursor A;

[0078] (2) Precursor A and glucose are dispersed in ethanol at a mass ratio of 70:30, and dried to obtain Precursor B;

[0079] (3) Precursor B was placed in a box furnace, fed with nitrogen, and the temperature was raised to 800 °C to obtain a core-shell composite negative electrode material with a carbon coating thickness of 0.5 μm.

[0080] The core-shell type composite negative electrode material obtained in this example includes: an inner core formed by a first active material a...

Embodiment 2

[0084] This embodiment provides a core-shell composite negative electrode material and a preparation method thereof, the method comprising the following steps:

[0085] (1) Flake silicon with a median diameter of 200nm and an aspect ratio of 25, a flake-shaped Si-Fe alloy with a median diameter of 900nm and an aspect ratio of 7.0, and a flake-shaped Si-Fe alloy with a median diameter of 8μm and an aspect ratio of 3 Artificial graphite is mixed and heated according to the mass ratio of 45:5:50 to obtain precursor A;

[0086] (2) Precursor A and pitch are placed in a mixer in a mass ratio of 80:20 and mixed to obtain precursor B;

[0087] (3) Precursor B was placed in a tube furnace, argon gas was introduced, and the temperature was raised to 900° C. to obtain a core-shell composite negative electrode material with a carbon coating thickness of 0.3 μm.

Embodiment 3

[0089] This embodiment provides a core-shell composite negative electrode material and a preparation method thereof, the method comprising the following steps:

[0090] (1) Flake SiO with a median particle size of 200 nm and an aspect ratio of 4 1.05 A flaky Si-Cu alloy with a median particle size of 600 nm and an aspect ratio of 10 and a flaky natural graphite with a median particle size of 10 μm and an aspect ratio of 21 were spray-dried to obtain the precursor A at a mass ratio of 30:35:35;

[0091] (2) Precursor A is placed in a rotary furnace, acetylene gas is passed through, and precursor B is obtained by depositing at 800°C for 2 hours;

[0092] (3) Precursor B was placed in a roller kiln, nitrogen gas was introduced, and the temperature was raised to 700°C to obtain a core-shell composite negative electrode material with a carbon coating thickness of 0.1 μm.

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Abstract

The invention discloses a core-shell type composite negative electrode material, a preparation method and applications thereof, the composite negative electrode material comprises an inner core formedby a first active substance and a second active substance, and a carbon coating layer shell used as a third active substance, the first active substance is a sheet-shaped silicon-based material, andthe second active substance is a silicon-based material. The second active substance is a flake graphite material, and the third active substance is a carbon-coated shell. The composite material disclosed by the invention is used for the negative electrode of the lithium ion battery, and has high specific capacity (the capacity is greater than 400mAh / g) and excellent cycle life. The method is simple in process and easy for large-scale production.

Description

technical field [0001] The invention belongs to the application field of lithium-ion battery negative electrode materials, and relates to a composite negative electrode material, its preparation method and application, in particular to a core-shell type high-capacity long-cycle composite negative electrode material for lithium-ion batteries, its preparation method and the composite materials for lithium-ion batteries. Background technique [0002] Lithium-ion batteries have been widely used due to their long cycle life, high specific energy, and good safety performance, and have received close attention from all sides. As a traditional lithium-ion battery anode material, graphite material has stable electrochemical performance, but its own specific capacity is not high, the theoretical capacity is only 372mAh / g, which cannot meet the increasing demand for high-energy-density lithium-ion batteries in today's market. The theoretical specific capacity of silicon-based negative...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/583H01M4/134H01M4/133H01M10/0525
CPCH01M4/362H01M4/386H01M4/583H01M4/134H01M4/133H01M10/0525Y02E60/10H01M4/364H01M4/366H01M4/587H01M2004/027H01M4/1393H01M4/1395H01M4/483H01M10/052H01M2004/021
Inventor 何鹏郭锷明任建国贺雪琴
Owner BTR NEW MATERIAL GRP CO LTD
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