Lithium ion battery and negative electrode active material thereof

A negative electrode active material, lithium-ion battery technology, applied in battery electrodes, secondary batteries, circuits, etc., can solve the problems of low reversible capacity, low coulombic efficiency, poor cycle performance, etc., to improve the first efficiency, increase rate performance, The effect of structural stability

Inactive Publication Date: 2012-01-25
DONGGUAN AMPEREX TECH +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] One of the purposes of the present invention is to provide a Si-based negative electrode active material for lithium ion batteries, which overcomes the problems of low reversible capacity and low Coulombic efficiency of existing Si-based negative electrode active materials, especially the problem of poor cycle performance, thereby improving the existing Si-based negative electrode active materials. Capacity, efficiency, cycle characteristics, and stability of lithium-ion batteries using Si-based anodes

Method used

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  • Lithium ion battery and negative electrode active material thereof
  • Lithium ion battery and negative electrode active material thereof
  • Lithium ion battery and negative electrode active material thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Put 50g of mixed graphite (D50=20μm, natural graphite accounts for 50%) into a vacuum furnace, 4 The gas is used as silicon source (flow rate 300ml / min), heated to 900°C and kept at constant temperature for 15h. After cooling, put it into a vacuum furnace, feed acetylene as carbon source gas (flow rate 300ml / min), and keep the temperature constant for 20h. The diameter of the nano-silicon wire on the surface of the obtained negative electrode active material is about 100-300 nm, and the length is about 10-20 μm; the thickness of the amorphous carbon coating layer is about 55 nm. The XRD pattern of above-mentioned material is as figure 1 As shown, its SEM surface morphology analysis is as follows figure 2 shown.

[0040] The initial reversible capacity of the above-mentioned negative electrode active material measured in the button battery is 580mAh / g, the initial efficiency is 89%, and the capacity retention rate after 50 cycles is 95%. The capacity of the above-me...

Embodiment 2

[0042] Put 50g of natural graphite (D50=18μm) into the vacuum furnace, 4 The gas is used as silicon source (flow rate 300ml / min), heated to 900°C and kept at constant temperature for 40h. After cooling, put it into a vacuum furnace, feed methane as carbon source gas (flow rate 300ml / min), and keep the temperature constant for 40h. The diameter of the nano-silicon wire on the surface of the obtained negative electrode active material is about 300-500 nm, and the length is about 40-80 μm; the thickness of the amorphous carbon coating layer is about 80 nm.

[0043] The initial reversible capacity of the above-mentioned negative electrode active material measured in the button battery is 1200mAh / g, the initial efficiency is 89%, and the capacity retention rate after 50 cycles is 88%.

Embodiment 3

[0045] Put 50g of artificial graphite (D50=20μm) into the vacuum furnace, 4 The gas is used as silicon source (flow rate 300ml / min), heated to 900°C and kept at constant temperature for 10h. After cooling, put it into a vacuum furnace, feed acetylene as carbon source gas (flow rate 300ml / min), and keep the temperature constant for 10h. The diameter of the nano-silicon wire on the surface of the obtained negative electrode active material is about 80-200 nm, the length is about 5-20 μm; the thickness of the amorphous carbon coating layer is about 40 nm.

[0046] The initial reversible capacity of the above-mentioned negative electrode active material measured in the button battery is 550mAh / g, the initial efficiency is 89%, and the capacity retention rate after 50 cycles is 90%. The initial reversible capacity of the above-mentioned negative electrode active material in the 454261 pouch battery is 1650mAh, the initial efficiency is 89%, and the capacity retention rate after 50...

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Abstract

The invention which belongs to the technical field of lithium ion batteries especially relates to a lithium ion battery and a negative electrode active material thereof. The negative electrode active material comprises graphite, silicon nanometer wires growing on graphite, and an amorphous carbon layer coated on the silicon nanometer wires. The lithium ion battery prepared with the negative electrode active material has the characteristics of high first efficiency, high capacity, low expansion, excellent cycle performance and the like. The invention also provides the lithium ion battery with the negative electrode active material.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium ion battery negative electrode active material and a lithium ion battery using the negative electrode active material. Background technique [0002] Due to a series of advantages such as high energy density, high working voltage, light weight, no memory effect and environmental friendliness, lithium-ion batteries have attracted widespread attention and developed rapidly since their birth. With the rapid development of electronic technology, people put forward higher energy density and longer cycle performance requirements for lithium-ion batteries. Therefore, it is particularly important to develop materials for lithium-ion batteries with high specific capacity and excellent cycle performance. [0003] The traditional lithium battery negative electrode material is mainly graphite, and its theoretical lithium storage capacity is about 372mAh / g,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/38H01M4/134H01M4/1395H01M10/0525
CPCY02E60/122Y02E60/10
Inventor 程晓燕华斌陈振许瑞赵丰刚
Owner DONGGUAN AMPEREX TECH
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