| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery which is excellent not only in discharge capacity but also excellent in high cycle capacity retention by setting a volume resistivity value of a negative electrode mix layer of a secondary battery having a negative electrode having the negative electrode mix layer mainly composed of a carbon material so as to become a specific range. SOLUTION: A negative electrode mix layer is set so that its volume resistivity value becomes 0.1 to 1 Ωcm. A carbon material to be used is graphite on which spacing of a (d002) surface in X-ray diffraction is less than 0.338 nm, and is artificial graphite powder graphitized in a powder shape. It is desirable that the specific surface area measured by a BET method is less than 3 m<2> /g by containing the artificial graphite powder graphitized in a powder shape and a scale-shaped graphite powder. The volume resistivity value of the negative electrode mix layer can be changed by adjusting porosity by pressure at pressing time by drying this after, for example, a carbon material of a negative electrode is applied to a surface of a current collecting body. When its volume resistivity value is less than 0.01 Ωcm, discharge capacity reduces. |
