Sumitomo Chemical Company, Limited

Yuki Yoneguchi

Atsuhiro Takata

Yoshinori Sato

Akinori Bando

Daisuke Yamaguchi

A nonaqueous electrolyte secondary battery separator having excellent impact absorbency includes a polyolefin porous film having a full width W at half maximum of a peak of an MD component of not less than 30 degrees. The full width W at half maximum of the peak of the MD component is calculated from an azimuthal profile of a scattering peak on a plane obtained by wide-angle X-ray scattering measurement that is carried out by irradiating a surface of the polyolefin porous film with an X-ray from a direction vertical to the surface of the polyolefin porous film, and/or having a maximum-to-minimum intensity ratio r of not more than 3.6. The maximum-to-minimum intensity ratio r is calculated from a Fourier transformed azimuthal profile obtained by observing the surface of the polyolefin porous film by SEM.

Nonaqueous electrolyte secondary battery separator, nonaqueous electrolyte secondary battery member, and nonaqueous electrolyte secondary battery

A nonaqueous electrolyte secondary battery separator which has a low shutdown temperature, a high mechanical strength, and a high ion permeability is provided. The nonaqueous electrolyte secondary battery separator contains a polyolefin-based resin as a main component. The nonaqueous electrolyte secondary battery separator has a maximum heating value of not less than 30 mW/g observed during isothermal crystallization of the nonaqueous electrolyte secondary battery separator at 128&#xb0; C.

Growing community of inventors

Niihama, Japan

Yuki Yoneguchi