Separator for nonaqueous electrolyte secondary battery, member for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery

The present invention addresses the problem of providing a separator for a non-aqueous electrolyte secondary battery, said separator having excellent shock absorption properties. A separator for a non-aqueous electrolyte secondary battery according to one embodiment of the present invention comprises a polyolefin-containing porous film in which the half-width W of a component in the MD direction is 30 degrees or more as calculated on the basis of an azimuth distribution curve of scattering peaks in the (110) plane obtained by wide-angle X-ray scattering measurement performed by irradiating the surface with X-rays from the vertical direction. And/or the maximum/minimum intensity ratio (r) calculated on the basis of a Fourier transform azimuth distribution curve obtained by SEM observation from the surface is 3.6 or less. 本发明的课题在于提供一种冲击吸收性优异的非水电解液二次电池用隔膜。本发明的一个实施方式涉及的非水电解液二次电池用隔膜含聚烯烃多孔膜，其基于通过对表面从铅直方向照射X射线而进行的广角X射线散射测定得到的(110)面的散射峰的方位角分布曲线算出的、MD方向成分的半峰宽W为30度以上，和/或基于从表面通过SEM观察得到的傅里叶变换方位角分布曲线算出的最大最小强度比r为3.6以下。