Carbon powder for use in cathode materials of non-aqueous secondary battery

A technology of carbon powder and pitch powder, which is applied in the field of carbon powder of negative electrode materials for non-aqueous secondary batteries, can solve the problems of no electrode density and resistance to PC electrolyte, and achieve superior resistance to PC electrolyte and improve Excellent PC electrolyte resistance and rate characteristics

Inactive Publication Date: 2007-02-07
CHUO DENKI KOGYO CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this patent document, there is no description of electrode density and PC electrolyte resistance

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0063] As the base material, natural graphite powder with an average particle size of 20 μm and a specific surface area of ​​5.2 m was used. 2 / g, in the pore distribution curve obtained by analyzing the isotherm on the nitrogen desorption side by the BJH method, the volume of pores with a pore diameter of 50 to 200 nm is 0.0110 cm 3 / g, 1360cm in argon ion laser Raman spectrum -1 The peak intensity near 1580cm -1 The value of the ratio R of the peak intensity in the vicinity is 0.19, and the natural graphite powder which was spheroidized and pulverized.

[0064] 5 parts of coal-based pitch powder having an average particle diameter of 35 μm and a softening temperature of 80° C. and 100 parts of the natural graphite powder were mixed in a solid phase by simple mixing using a V mixer. The obtained mixed powder was put into a graphite crucible, and heat-treated at 1000° C. for 1 hour under a nitrogen gas flow, thereby obtaining carbon powder.

[0065] The pore distribution an...

Embodiment 2

[0068] Carbon powder was obtained in the same manner as in Example 1 except that the amount of the pitch powder was changed to 9 parts. The V2 / V1 value of the obtained carbon powder was 1.11, and the V4 / V3 value was 1.87.

[0069] The carbon powder sample obtained in Example 2 was observed with a TEM (transmission electron microscope). In a part of the powder surface where the edge face and the base face can be clearly distinguished, a structure in which carbon (derived from low-temperature fired carbon with an underdeveloped crystal structure) adhered to the edge face was observed, and the carbon had a turbostratic structure.

Embodiment 3

[0073] As the base material, natural graphite powder with the following conditions was used, namely: average particle size 29 μm; specific surface area 3.5 m 2 / g; in the pore distribution curve obtained by analyzing the nitrogen desorption side isotherm by the BJH method, the volume of pores with a diameter of 50-200nm is 0.0072cm 3 / g; Argon ion laser Raman spectrum, 1360cm -1 The peak intensity near 1580cm is relative to -1 The ratio R of the peak intensity in the vicinity is 0.16, and the natural graphite powder was spheroidized and pulverized.

[0074] 5 parts of coal-based pitch powder having an average particle diameter of 35 μm and a softening temperature of 80° C. and 100 parts of the graphite powder were mixed in a solid phase by simple mixing using a V mixer. This mixed powder was put into a graphite crucible, and heat-treated at 900° C. for 1 hour under a nitrogen gas stream, whereby carbon powder was obtained. The value of V2 / V1 of the obtained carbon powder wa...

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Abstract

The invention provides low cost carbon powder which does not decompose propylene carbonate to be used as a negative electrode material of a low temperature-operable nonaqueous secondary battery. The carbon powder obtained by depositing low temperature fired carbon originating in pitch on a part of the surface of natural graphite powder is made by mixing the natural graphite powder with pitch powder of a carbon precursor in a solid state and heating at 900-1,500 deg C to carbonize the pitch. The quantity of the pitch powder is controlled so that the ratio V2/V1 of the pore volume (V1) of poreshaving 2-50 nm pore diameter to the pore volume (V2) of pores having 50-200 nm pore diameter in the pore distribution curve determined by analyzing nitrogen desorption side isotherm of the resultant carbon powder by the BJH method is >=1.

Description

technical field [0001] The present invention relates to an inexpensive carbon powder in which carbon with a low degree of graphitization is adhered to a part of the surface of a natural graphite powder, and particularly relates to a carbon powder suitable for a negative electrode material for a nonaqueous secondary battery. Background technique [0002] Lithium-ion secondary batteries are rapidly spreading as power sources for portable electronic devices and the like. The negative electrode material of non-aqueous secondary batteries typified by lithium ion secondary batteries is carbon powder. Due to the demand for high capacity of small batteries, negative electrode materials are also seeking high capacity. In current non-aqueous secondary batteries, artificial graphite powder that has been graphitized is mainly used as a negative electrode material. Since the capacity per unit volume is further increased, the fillability of the electrode is improved, that is, the densit...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/02H01M4/38B82Y30/00B82Y99/00H01M4/02H01M4/36H01M4/583H01M4/587H01M10/05
CPCY02E60/12Y02E60/10H01M4/02H01M4/583H01M2004/027
Inventor 山本浩司藤原彻
Owner CHUO DENKI KOGYO CO LTD
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