Nonaqueous electrolyte secondary battery

摘要

A nonaqueous electrolyte secondary battery provided by the present invention includes an electrode body in which a positive electrode sheet and a negative electrode sheet 20 are laminated with a separator sheet 40 interposed therebetween. A porous layer 42 including an inorganic filler and a binder is formed on at least one surface of the separator sheet 40. The surface of the porous layer 42 is made uneven by forming peaks and valleys, and a maximum difference of elevation on an uneven surface 42a is 0.2 μm to 1.7 μm.

主权项

1. A nonaqueous electrolyte secondary battery, comprising:
a positive electrode sheet; a negative electrode sheet; a separator sheet interposed between the positive electrode sheet and the negative electrode sheet; and a porous layer formed on the separator sheet; wherein the porous layer including an inorganic filler and a binder, and a surface of the porous layer is made uneven by forming peaks and valleys, and a maximum difference of elevation δ on an uneven surface is 0.2 μm to 1.7 μm, wherein the maximum difference of elevation δ is determined by (1) selecting three equidistant locations in a transverse direction and selecting three locations with a reference length interval of 3 cm in a machine direction (a total of nime locations), (2) observing a cross-section of the porous layer at each location by an electron microscope, (3) measuring a distance between a highest point and a lowest point on the uneven surface within the reference length of 3 cm at each location, and (4) calculating an average value of the distance.