Porous membrane for secondary battery, slurry for secondary battery porous membrane and secondary battery

摘要

The porous membrane according to the present invention comprises non-conductive particles, a binder, and a water-soluble polymer, and is characterized in that: the three dimensions of the non-conductive particles, namely the length (L), thickness (t), and width (b), are such that the length (L) is 0.1 to 0 μm, the ratio (b/t) of the width (b) and the thickness (t) is 1.5 to 100; the binder is a copolymer containing (meth)acrylonitrile monomer units and (meth)acrylic acid ester monomer units; and the water-soluble polymer contains sulfonic acid groups, and has a weight average molecular weight of 1000 to 15000. The slurry for a porous membrane according to the present invention is characterized by being formed by dispersing the non-conductive particles, the binder, and the soluble polymer, in water. Thus, the present invention provides: a porous membrane that can be formed into a thin film, has an excellent sliding property, and generates few particles; and a slurry for porous membranes which is capable of producing porous membrane easily and quickly, and has excellent storage stability.

主权项

1. A porous membrane for a secondary battery including a non-conductive particle, a binder and an aqueous polymer; wherein:
said non-conductive particle long diameter L is 0.1 to 20 μm and ratio (b/t) between width (b) and thickness (t) is 1.5 to 100, said binder is a copolymer including (meth)acrylonitrile monomer unit and (meth)acrylate monomer unit; and said aqueous polymer includes sulfonic acid group and a weight average molecular weight is 1000 to 15000.