| 摘要 |
<p>Provided is a finely fibrous structure which renders smooth ion conduction possible and hence attains excellent capacity retentivity with high rates and which is suitable for use as a separator for batteries, electric double-layer capacitors, capacitors, etc. The finely fibrous structure comprises a finely fibrous layer constituted of fine polymeric fibers having an average diameter of 50-3,000 nm, and is characterized in that each surface of the finely fibrous structure has a surface roughness (Ra) of 0.01-10 µm and a 10-point average height (Rz) of 0.01-100 µm and that the finely fibrous layer has an average pore diameter of 0.01-15 µm, a thickness of 0.0025-0.3 mm, a porosity of 20-90%, a basis weight of 1-90 g/m2, a Frazier air permeability less than 46 m3/min/m2, and a Macmillan number of 2-15.</p> |
