A water control sheet having superior drainage and gas diffusion properties and superior handling characteristics, and a gas diffusion sheet, a membrane-electrode assembly and a polymer electrolyte fuel cell, which utilize the water control sheet, are prov...

Disclosed are a separator for lithium ion secondary batteries, having an inorganic layer formed from inorganic particles, characterized in that the inorganic particles have a particle diameter distribution in which the 50% cumulative particle diameter D 50...

Disclosed is a battery separator consisting essentially of a nonwoven fabric having a substantially unilayered structure, wherein an apparent total surface area of fibers per a surface density of the nonwoven fabric is 20 m or more, a thickness of the nonw...