| 摘要 |
PURPOSE: To obtain a microporous film resistant to the penetration of a zinc dendrite, usable as a battery separator, and enhance life cycle characteristic of the battery by coating a microporous film with a uniform porous cover of a specified low hydrogen overvoltage material. CONSTITUTION: An open cell type microporous film is formed by coating at least one surface with a uniform porous cover of a low hydrogen overvoltage material such as nickel. The microporous film when it is hydrophilic before coating, it has an electric resistance of about 7.75mΩ-cm<2> or lower, lower bulk density to a corresponding base not having open cell type structure, a surface area of at least 10m<2> /g, a mean pore diameter of about 200-10000Å, and after coating, the coating film thickness is controlled so that the electric resistance does not exceed a specified value. The open cell type microporous film is the most suitable as separators 7, 8 of a secondary battery having a zinc electrode, resistant to the penetration of a zinc dendrite, and lengthens the cycle life of the battery. |
