| abstract |
The present invention relates to a composite membrane that can be used in an electrochemical device such as a lithium secondary battery, a method for manufacturing the same, and an electrochemical device having the same. The composite membrane for an electrochemical device of the present invention includes a polyolefin-based microporous membrane; And a porous membrane on a web made of nanofibers bonded to at least one surface of the polyolefin-based microporous membrane. Since the composite membrane according to the present invention can absorb the electrolyte uniformly, the performance of the battery is greatly improved when used in an electrochemical device, and the mechanical strength is good and the binding with the electrode is good, thereby increasing the process speed of battery manufacturing. have. |