Showa Denko K.k.

Resonac Corporation

Daisuke Kohno

Akihisa Tonegawa

Daisuke Harada

Hirofumi Inoue

Yasuaki Wakizaka

A positive electrode mixture layer for a lithium-ion secondary battery suitable for producing a lithium-ion secondary battery with high rate characteristics at an ordinary temperature and low temperatures and low internal resistance (DCR) at low temperatures, characterized by including a positive electrode active material, a binder, and a conductive additive, in which the conductive additive includes carbon black, a carbon nanotube (1) having an average fiber diameter of 80 to 400 nm, and a carbon nanotube (2) having an average fiber diameter of 0.4 to 3.0 nm, the content rates of the carbon black, the carbon nanotube (1), and the carbon nanotube (2) in the conductive additive are 40 to 80% by mass, 10 to 50% by mass, and 1 to 30% by mass, respectively, and the content rate of the conductive additive in the positive electrode mixed layer is 0.1 to 5.0% by mass.

Positive electrode mixture layer, conductive additive, positive electrode mixture, and lithium-ion secondary battery

The present provides a carbon material containing 50 to 1,000 ppm by mass of vanadium (V), wherein a mean particle diameter D50 is 3 to 7 &#x3bc;m; a tapping density after 400 times of tapping is 0.40 to 1.00 g/cm; a BET specific surface area is 4.0 to 12.0 m/g; an R value (ID/IG) measured in the spectrum observed by Raman spectroscopy is 0.10 to 0.30; and an interplanar spacing dof plane (002) (nm) and Lc(nm) as being the size in the c-axis direction of the graphite crystals satisfy the relationship represented by the following formulae (1) and (2)0.3362&#x2264;d&#x2264;0.3370&#x2003;&#x2003;(1)&#x2212;23660&#xd7;+8010&#x2264;&#x2264;&#x2212;23660&#xd7;+8025&#x2003;&#x2003;(2);which is suitable for a non-aqueous electrolytic secondary battery having a low resistance and a high coulomb efficiency; a method for producing the same; a carbon material for a battery electrode; an electrode; and a lithium-ion secondary battery using the above-described carbon material.

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Tokyo, Japan

Daisuke Kohno