COMPOSITE MEMBRANE FOR ELECTROCHEMICAL DEVICES CAPABLE OF ABSORBING ELECTROLYTE UNIFORMLY, MANUFACTURING METHOD THEREOF AND ELECTROCHEMICAL DEVICE COMPRISING THE SAME

摘要

PURPOSE: Provided is a composite membrane for electrochemical devices, which can absorb an electrolyte uniformly to improve the quality of a battery, and has excellent mechanical strength and adhesion to an electrode to increase the workability in a battery manufacturing process. CONSTITUTION: The composite membrane for electrochemical devices comprises: a polyolefin-based microporous membrane; and a porous membrane in the form of a web comprising nanofibers, the porous membrane being bonded to at least one surface of the polyolefin-based microporous membrane. The polyolefin-based microporous membrane may be at least one membrane formed of polyethylene polymers or polypropylene polymers. The polyolefin-based microporous membrane has a thickness of 5-50 micrometers and porosity of 30-80%, and the nanofiber has a diameter of 50-2000 nm.