| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress an occurrence of crushes of pores on a separator surface due to expansion of an electrode, thereby suppressing deterioration in battery characteristics. <P>SOLUTION: In a nonaqueous electrolyte battery, a separator is used, the separator including: a base material made of a porous film; and a porous surface layer formed on at least one side of the base material, having a surface with an irregular shape, and having porosity higher than that of the base material. The surface layer includes: a first layer comprising a porous projecting part and a recessed part existing as a gap; and a porous second layer formed between the first layer and the base material. It is preferable that the second layer has porosity higher than that of the base material and the first layer has porosity higher than that of the second layer. Here, it is preferable that the base material has porosity of 25% or more and 40% or less, the first layer has porosity of 60% or more and 90% or less, and the second layer has porosity of 40% or more and 65% or less. <P>COPYRIGHT: (C)2013,JPO&INPIT |
