| 摘要 |
PURPOSE:To increase filling capacity per unit volume of a positive electrode black mixture by mixing two kinds of artificial graphite having a properly large specific surface area and artificial graphite having a relatively small surface area for being used as a conductive material of MnO2. CONSTITUTION:A lithium negative electrode 2 and a positive electrode plate 3 are provided inside a cell container 1 of nickel-plated iron. Positive electrode black mixture mainly consisting of heat treated electrolyte MnO2 power is mixed with two kinds of graphite having a specific surface area of 300m<2>/g and that of 10m<2>/g as a conductive material. Thereby, artificial graphite of 300m<2>/g fully secures inter-particle electron conductive network of MnO2, on the other hand, artificial graphite of 10m<2>/g increases filling capacity, since the black mixture displays a sliding effect at the time of rolling. Further, by mixing artificial graphite having a large specific surface area with artificial graphite having a small specific surface area, the synergistic effect consisting of an improved electron conductive network and increased filling density is displayed. |
