| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a separator for a lithium secondary battery, excellent in winding performance and resistance to lithium dendrite, and a lithium secondary battery excellent in a discharge capacity maintenance rate. <P>SOLUTION: This separator for the lithium secondary battery comprises a wet type nonwoven fabric containing: an ultrafine fiber obtained by splitting a split type composite fiber in which polyester and polyolefin are adjacent to each other; and a beaten solvent spinning cellulose fiber, the modified freeness of the beaten solvent spinning cellulose fiber defined by the following is 0-400 ml, and a length-weighted average fiber length is 0.20-2.00 mm. Modified freeness: a 80 mesh wire net having a wire diameter of 0.14 mm and an aperture of 0.18 mm is used for a sieve plate, and sample concentration is 0.1%. Other than that, the freeness is measured in conformity to JIS P8121. <P>COPYRIGHT: (C)2013,JPO&INPIT |
