SEPARATOR FOR ELECTROCHEMICAL ELEMENT, AND ELECTROCHEMICAL ELEMENT INCLUDING SAME

摘要

Disclosed is a separator for electrochemical elements which comprises fine inorganic particles and a fibrous object or microporous film, characterized in that the primary particles of the fine inorganic particles can be approximated to a geometrical shape and that the difference between a theoretical specific surface area of the fine inorganic particles and the actual specific surface area of the fine inorganic particles determined by the BET method is within ±15% of the theoretical specific surface area, the theoretical specific surface area being calculated from the surface area, volume, and true density of the primary particles of the fine inorganic particles which were determined through approximation of the primary particles of the fine inorganic particles to the geometrical shape.