Abstract:
A battery includes a positive electrode, a negative electrode, a separator interposed therebetween, and an electrolyte. The separator includes a plurality of nanofibers and has a form of a sheet having a first surface and a second surface opposite thereto. When the average maximum fiber diameter of the nanofibers in the plane direction of the separator is compared between in vicinities of the first and second surfaces and at a center portion in the thickness direction of the separator, average maximum fiber diameters Ds1 and Ds2 of the nanofibers in the vicinity of the first and second surfaces are smaller than an average maximum fiber diameter Dc of the nanofibers at the center portion in the thickness direction of the separator.
Abstract:
A nonwoven fabric includes a fiber including a first portion and a second portion connected to the first portion. A first fiber diameter of the first portion is smaller than a reference fiber diameter. A second fiber diameter of the second portion is equal to or greater than the reference fiber diameter. The reference fiber diameter is smaller than 1 μm. A ratio of a maximum fiber diameter of the second portion to a length of a linear line connecting both end portions of the second portion is from 1/10 to ⅓.
Abstract:
A laminated nonwoven fabric includes a first nonwoven fabric that comprises first fibers, and a second nonwoven fabric that comprises second fibers. The second nonwoven fabric is laminated on the first nonwoven fabric. An average fiber diameter D1 of the first fibers and an average fiber diameter D2 of the second fibers satisfy a relation of D1>D2. In viewed from a side of a principal surface of the second nonwoven fabric being not opposed to the first nonwoven fabric, a total area of first portions of the second fibers superimposed on the first fibers and existing on the nearer side than the first fibers is larger than a total area of second portions of the second fibers existing and superimposed on voids S of the first nonwoven fabric formed of the first fibers.