| abstract |
The separator for an electrochemical device according to the present invention has a small content of secondary particles in which inorganic particles are aggregated in the inorganic coating layer. Particularly, the amount of secondary particles protruding more than a predetermined height to the surface of the separation membrane is small. In this way, when the separator according to the present invention is applied to a battery because inorganic particles are not aggregated in the inorganic coating layer as described above, the pressure is evenly distributed over the entire surface of the separator when pressure is generated in the battery due to charging and discharging of the battery, thereby preventing deformation of the separator. Can be minimized. On the other hand, when a porous film made of a polymer material is used as the separator substrate, the tendency of the pressure to be intensively applied to the local portion of the separator substrate by the secondary particles decreases, so that damage to the separator substrate is reduced, and accordingly, the occurrence rate of a short circuit is lowered. |