摘要 |
A battery separator (13) of the present invention includes a porous film (12) serving as a substrate and a crosslinked polymer layer (11) supported on the porous film (12). The crosslinked polymer layer (11) contains a crosslinked polymer and inorganic particles, and is non-porous. The crosslinked polymer is obtained by reacting a reactive polymer having a functional group in its molecule with a polyfunctional compound reactive with the functional group so as to crosslink at least a part of the reactive polymer. A lithium ion secondary battery of the present invention includes a positive electrode (14), a negative electrode (15), the battery separator (13) of the present invention disposed between the positive electrode (14) and the negative electrode (15), and a non-aqueous electrolyte solution. The battery separator (13) is disposed so that the porous film (12) faces the negative electrode (15) and the crosslinked polymer layer (11) faces the positive electrode (14). |