Battery separator and battery including the same

PROBLEM TO BE SOLVED: To improve characteristics of a battery separator such as a tensile characteristic and resistance in electrolyte while keeping an electrolyte absorbing property, size stability after wetting, and electrolyte resistance excellent. SOLUTION: A battery separator is constirocted of nonwoven fabric (a), which is made of fiber with a mean diameter of about 15 μm or less, and a graft polymerized monomer (b), which is applied onto the surface of the nonwoven fabric (a) so as to provide a spontaneous wettability based on alkaline electrolyte to the nonwoven fabric (a). The nonwoven fabric (a), which contains about 60 wt.% of first polyolefine (polypropylene, for example) provided with the first melting temperature and about 40 wt.% of second polyolefin (polyethylene, for example) provided with the second melting temperature lower than the first melting temperature, is treated at a temperature between the first and second melting temperatures. The thickness of the nonwoven fabric (a) is about 50 μm or more.