| abstract |
A separator for an electrochemical device according to the present invention has a low content of secondary particles that are inorganic particles aggregated in an inorganic coating layer. In particular, the amount of secondary particles protruding above a predetermined height toward the surface of the separator is small. Since, as described above, the inorganic particles are uniformly distributed and not aggregated in the inorganic coating layer, when the separator according to the present invention is applied to a battery, pressure generated inside the battery due to charging/discharging of the battery is evenly distributed over the entire surface of the separator, and thus deformation of the separator is minimized. Meanwhile, when a porous film made of a polymer material is used as a separator substrate, the tendency for the pressure to be concentrated in a localized portion of the separator substrate due to the secondary particles decreases, so that damage to the separator substrate is reduced, and accordingly, the rate at which short circuiting occurs is reduced. |