Spherical silicon carbon composite anode material of lithium ion battery and preparation method for spherical silicon carbon composite anode material

A technology for lithium-ion batteries and negative electrode materials, applied to battery electrodes, circuits, electrical components, etc., can solve the problems that cannot completely solve the problem of silicon powder exposure, and it is difficult to fully utilize the buffer mechanism of graphite, so as to reduce the probability of dispersion and exposure. The effect of good cycle performance and complete configuration rules

Inactive Publication Date: 2012-10-03
力芯(青岛)新能源材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The electrochemical performance of Si / graphite / carbon is largely determined by the structure of the composite material. People have conducted research on what kind of silicon-carbon composite material with a specific structure is formed, and how to form a silicon-carbon composite material with a specific structure. For example, Li Hong et al. A silicon-carbon composite material with a "Yuanxiao" structure was invented by mixing spherical graphite and silicon powder by stirring (Chinese patent authorization announcement number CN 1328805C). The mechanical force of graphite and the prepared materials cannot completely solve the problem of silicon powder exposure, so it is difficult to give full play to the buffer mechanism of graphite

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  • Spherical silicon carbon composite anode material of lithium ion battery and preparation method for spherical silicon carbon composite anode material
  • Spherical silicon carbon composite anode material of lithium ion battery and preparation method for spherical silicon carbon composite anode material
  • Spherical silicon carbon composite anode material of lithium ion battery and preparation method for spherical silicon carbon composite anode material

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Embodiment 1

[0031] Example 1. Natural flake graphite with a median diameter of 5μm and an aspect ratio of 10, metallic silicon with a median diameter of 0.5μm and pitch (carbonized) were mixed with tetrahydrofuran with a mass ratio of 88:6:6 and 100% by mass. In a twin-shaft mixer, mix at 160°C for 1 hour, remove the tetrahydrofuran solvent under reduced pressure, calcined at 400°C for 5 hours, pulverize appropriately, and sieve to obtain precursor particles with a median diameter of 30μm. The precursor particles are observed by SEM. The particles are not completely spherical, the graphite is exposed, and the surface is relatively rough. Put the precursor into a fine particle pelletizing system, and shape it at a rotation speed of 1200 rpm for 45 minutes. The processed material is heated at 6°C / min to 1000°C in a nitrogen atmosphere and calcined for 5 hours to obtain a spherical silicon-carbon composite anode material. SEM observation of the composite material showed a spherical structure,...

Embodiment 2

[0034] Example 2. Deionization of artificial flake graphite with a median diameter of 3μm and an aspect ratio of 15, metal silicon and PVA with a median diameter of 0.3μm in a mass ratio of 88:5:7 (carbonized) and 100% by mass Mix with water, mix at 200°C for 1 hour, remove the deionized water solvent under reduced pressure, calcinate at 400°C for 4 hours, and pulverize appropriately to prepare precursor particles with a median diameter of 22μm. The precursor particles are not completely spherical according to SEM observation. , Graphite is exposed and the surface is rough. Put the body into the fine particle pelletizing system, and shape it at a rotation speed of 1500 rpm for 30 minutes. The processed material is heated at 5°C / min to 900°C in a nitrogen atmosphere and calcined for 6 hours to obtain a spherical silicon-carbon composite anode. Material, the composite material has a spherical structure observed by SEM, and its physical properties are shown in Table 2.

[0035] The...

Embodiment 3

[0036] Example 3. The artificial flake graphite with a median diameter of 10μm and an aspect ratio of 10, metallic silicon with a median diameter of 0.3μm and pitch (carbonized) were mixed with a mass ratio of 86:6:8 with 100% tetrahydrofuran. In a twin-shaft mixer, mix at 150°C for 2 hours, remove the tetrahydrofuran solvent under reduced pressure, calcined at 300°C for 8 hours, pulverize appropriately, and sieve to obtain precursor particles with a median diameter of 35μm. The precursor particles are observed by SEM. The particles are not completely spherical, the graphite is exposed, and the surface is relatively rough. In the fine particle pelletizing system, the solvent is removed and the spheroidization treatment is carried out at a constant temperature of 120°C, and the treatment is performed at a rotation speed of 1200 rpm for 120 minutes. The obtained spherical particle precursor is heated at 5°C / min in a nitrogen atmosphere. Calcined at 1000°C for 8 hours, spherical s...

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Abstract

The invention provides a spherical silicon carbon composite anode material of a lithium ion battery and a preparation method for the spherical silicon carbon composite anode material. The spherical silicon carbon composite anode material comprises 5 to 12 percent of silicon, 68 to 90 percent of graphite and the balance of carbon material. A spherical precursor is prepared from silicon powder, flake graphite and the carbon source material by a constant-temperature mixing technology; and the spherical silicon carbon composite anode material is prepared by balling high-temperature thermal treatment, wherein the core of spherical silicon carbon composite anode material is anisotropically distributed and the surface of the flake / carbon is wrapped by the carbon material. In the spherical silicon carbon composite anode material, the reversible capacity can reach more than 480 Ah / g; the sequential efficiency at the first time can reach over 85 percent; and the capacity retention rate after circulation is performed for 300 times is more than 87 percent.

Description

[0001] Technical field [0002] The invention relates to a lithium ion battery silicon-carbon composite negative electrode material and a preparation method thereof, in particular to a lithium ion battery spherical silicon-carbon composite negative electrode material and a preparation method thereof. [0003] technical background [0004] Lithium-ion batteries are currently the most widely used power equipment for providing energy for portable and powered vehicles, and graphite materials are the main negative electrode materials. However, in the process of commercial application, people’s requirements for high-energy power sources are getting higher and higher. In order to overcome the shortcomings of the limited lithium insertion capacity (372 mAh / g) of graphite materials, and to find better performance anode materials, people are looking for a variety of new Anode materials have been studied. Among them, Si-based anode materials have attracted the attention of researchers because...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/62H01M4/38
CPCY02E60/12Y02E60/10
Inventor 裴德成李博
Owner 力芯(青岛)新能源材料有限公司
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