| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide: a lithium ion secondary battery separator that has a low basis weight and strong mechanical strength and is excellent in internal resistance, internal short-circuit failure, and cycle characteristic; and a lithium ion secondary battery using the lithium ion secondary battery separator.SOLUTION: A lithium ion secondary battery separator contains 10-30 mass% of fibrillated solvent spinning cellulose fiber, 40-50 mass% of oriented, crystallized polyester short fiber having a mean fiber diameter of 2.0-3.5μm, and 30-40 mass% of polyester short fiber for undrawn binder having a mean fiber diameter of 5.0μm or less. A lithium ion secondary battery is configured by using the lithium ion secondary battery separator.</p> |
