Patent ID: 7662517

Claim:
An organic/inorganic composite porous separator, which comprises: (a) a polyolefin-based separator substrate; and (b) an active layer formed by coating at least one region selected from the group consisting of a surface of the substrate and a part of pores present in the substrate with a mixture of inorganic particles and a binder polymer, wherein the inorganic particles in the active layer are interconnected among themselves and are fixed by the binder polymer, and interstitial volumes among the inorganic particles form a pore structure, and the inorganic particles have a size between 0.001 μm and 10 μm and are present in the mixture of inorganic particles with the binder polymer in an amount of 50-99 wt % based on 100 wt % of the mixture, and wherein the separator has uniform pore structures both in the active layer and the polyolefin-based separator substrate.