Abstract: A PET nonwoven fabric for a separator for a secondary battery includes first fibers composed of PET having a melting temperature of 240° C. or more and second fibers composed of PET having a melting temperature of 180˜220° C., respective fibers having two types of fibers having different diameters, and has a fine pore size and uniform pore distribution and exhibits superior surface properties, low surface defects, high mechanical strength and excellent mass production. Even when the temperature of a battery is increased to 200° C. or more, the PET nonwoven fabric has heat resistance which prevents thermal runaway and does not generate melting and shrinking.

Abstract: A hybrid nonwoven separator having an inverted structure includes a nanofiber layer; and a substrate layer composed of a nonwoven fabric provided on both surfaces of the nanofiber layer to form an outermost layer. Because this separator is configured such that the substrate layer having a comparatively low coefficient of friction is disposed as the outermost layer thereof, structural defects generable in the course of manufacturing a separator can be prevented, thermal deformation of the nanofiber layer of the separator can be blocked, and also closure of pores of the nanofiber layer can be prevented thanks to pre-filtering, thus remarkably extending the lifespan of the separator.

Abstract: Provided is a separator having high wettability for a secondary battery, including a polyolefin substrate, a nanofiber hot melt layer formed on one or both surfaces of the substrate, and a nanofiber electrolyte wetting layer formed on the hot melt layer, wherein the hot melt layer is applied in an amount of 0.05˜2.5 g/m2, and the electrolyte wetting layer has a porosity of 55˜89%. The separator according to the current invention has superior heat resistance and high mechanical strength and can exhibit a shutdown function, and has superior porosity and pore size so as to be adapted for a separator for a secondary battery, thereby manifesting high ionic conductivity and preventing battery performance from deteriorating.

Abstract: A PET nonwoven fabric for a separator for a secondary battery includes first fibers composed of PET having a melting temperature of 240° C. or more and second fibers composed of PET having a melting temperature of 180˜220° C., respective fibers having two types of fibers having different diameters, and has a fine pore size and uniform pore distribution and exhibits superior surface properties, low surface defects, high mechanical strength and excellent mass production. Even when the temperature of a battery is increased to 200° C. or more, the PET nonwoven fabric has heat resistance which prevents thermal runaway and does not generate melting and shrinking.