| 摘要 |
PROBLEM TO BE SOLVED: To prevent performance degradation during storage while keeping heavy load discharge performance by using oil furnace black having a specific surface area in a certain range as carbon powder. SOLUTION: For a positive electrode mix, oil furnace black having a specific surface area of 50-80 m2/g measured by a BET method is used as carbon powder. Preferably, the oil furnace black should have an average fine hole diameter of 90-120Åand a total fine hole volume of 0.10-0.25 cc/g. Additionally, the degree of graphatization of the oil furnace black is preferably set to 3.50-3.65Å(using an graphite layer surface interval (d002) as an index). Manganese dioxide is used for an active material constituting the positive electrode mix, the blending ratio of the oil furnace black with it is preferably set in the range of 1/4-1/10 based on the weight ratio of the oil furnace black to manganese dioxide.
|
