Negative electrode material for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery using same

Abstract

Disclosed is a mixed carbon material for use in an electrode of a non-aqueous secondary battery showing excellent characteristics having rapid charge-discharge characteristics and high cycle characteristics. More particularly, disclosed is a negative electrode material for non-aqueous electrolyte secondary battery comprising the following carbon material A and carbon material B, wherein the carbon material A is a multilayer-structured carbon material which contains graphite particles and amorphous carbon covering the surfaces of the particles, and in which a 002 plane spacing (d002) measured by X-ray wide angle diffraction is 3.37Angstrom or less, Lc is 900Angstrom or more, a tap density is 0.8 g / cm<3> or more, and a Raman R value, which is the ratio of a peak intensity at around 1360 cm<-1> to a peak intensity at around 1580 cm<-1> in an argon ion laser Raman spectrum, is 0.25 to 0.6; and the carbon material B is graphite particles in which a 002 plane spacing (d002) measured by X-ray wide angle diffraction is 3.37Angstrom or less, Lc is 900Angstrom or more, a tap density is 0.8 g / cm<3> or more, a Raman R value, which is the ratio of a peak intensity at around 1360 cm<-1> to a peak intensity at around 1580 cm<-1> in an argon ion laser Raman spectrum, is 0.2 to 0.5, and an average circularity measured by a flow-type particle analyzer is 0.9 or more.

Description

technical field [0001] The present invention relates to a carbon material for a negative electrode of a non-aqueous electrolyte secondary battery. In addition, the present invention also relates to a negative electrode for a nonaqueous electrolyte secondary battery using the carbon material for a negative electrode, and a nonaqueous electrolyte secondary battery including the negative electrode. Background technique [0002] A nonaqueous lithium secondary battery including a positive electrode and a negative electrode capable of occluding and releasing lithium ions, and a nonaqueous electrolyte in which lithium salts such as LiPF6 and LiBF4 are dissolved has been developed and put into practical use. [0003] As the negative electrode material of this battery, various schemes have been proposed, but from the viewpoints of high capacity and excellent flatness of discharge voltage, artificial graphite obtained by graphitization of natural graphite, coke, etc., graphitized grap...

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Problems solved by technology

[0007] In order to improve cycle characteristics, for example, Patent Document 2 proposes a non-aqueous lithium secondary battery obtained by using the following carbonaceous particles and the following amorphous carbonaceous particles as negative electrode materials, wherein the carbonaceous particles have multiple layer structure, and the R value obtained by Raman spectroscopy is above 0.2; the crystallinity of the amorphous carbonaceous particles is low, and the X-ray interplanar distance d002 is However, this non-aqueous lithium secondary battery has the problem of an increase in irreversible capacity due to amorphous carbon particles, and further improvement in the cycle characteristics and rapid charge-discharge characteristics required for recent lithium secondary batteries is required.

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