BATTERY SEPARATOR, AND BATTERY SEPARATOR MANUFACTURING METHOD

摘要

A battery separator includes a porous membrane A including a polyethylene resin, and a porous membrane B laminated thereon including a heat resistant resin and inorganic particles or cross-linked polymer particles, wherein the porous membrane A satisfies expressions (a) to (c), and the entire battery separator satisfies expressions (d) to (f).

主权项

1. A battery separator comprising: a porous membrane A comprising a polyethylene resin, and a porous membrane B laminated thereon comprising a heat resistant resin and inorganic particles or cross-linked polymer particles,
wherein the porous membrane A satisfies expressions (a) to (c) below, the battery separator satisfies (d) to (f), and the heat resistant resin comprises a fluororesin:
t(A)<10 μm  (a) wherein t(A) is a thickness of the porous membrane A;
0.01 μm≦R(A)≦1.0 μm  (b) wherein R(A) is an average pore size of the porous membrane A;
30%≦V(A)≦70%  (c) wherein V(A) is a porosity of the porous membrane A:
t(T)≦13 μm  (d) wherein t(T) is a thickness of the battery separator;
F(A/B)≧1.0 N/25 mm  (e) wherein F(A/B) is a peeling strength at an interface between the porous membrane A and the porous membrane B; and
20≦Y−X≦100  (f) wherein X is an air resistance (sec/100 cc Air) of the porous membrane A, and Y is an air resistance (sec/100 cc Air) of the entire-battery separator.