| 摘要 |
PURPOSE:To improve the reaction utilization factor of MnO2 by specifying average grain sizes of MnO2 powder used as a positive electrode active material constituting a positive electrode black mix and two kinds of graphite powder used as a conductive agent. CONSTITUTION:Graphite powder consists of two kinds having different average grain sizes, the average grain size of one graphite powder is larger than that of the other graphite powder but smaller than that of manganese dioxide powder. The graphite powder having a smaller average grain size exists on the surface of MnO2 powder and forms electrochemical reaction type reaction sites on the surface of MnO2 powder. On the other hand, the graphite powder having a larger average grain size exists among the MnO2 powder holding the graphite powder having a smaller average grain size and forms a conductive passage. Accordingly, many reaction sites are formed, the electric conductivity of the whole positive electrode is increased, and the reaction utilization factor of MnO2 can be improved. |
