Patent attributes
A battery separator comprising a nonwoven fabric, wherein the nonwoven fabric contains (1) superfine fibers having a fiber diameter of 3 μm or less, (2) noncircular fine fibers having a noncircular cross-sectional shape and having a fiber diameter of 3 to 5 μm (excluding 3 μm), the fiber diameter meaning a diameter of a circle having an area the same as that of the noncircular cross-sectional shape, and (3) polypropylene based high-strength composite fibers containing a fusible component on the surface thereof and having a tensile strength of 4.5 cN/dtex or more, and the fusible component contained in the polypropylene based high-strength composite fibers is fused, and a battery comprising the battery separator are disclosed. A battery separator of the present invention has a high electrolyte-holding capacity and is capable of effectively preventing a short circuit, even if the separator is designed to be thinner to enhance the capacity of a battery.
