ELECTROLYTIC COPPER FOIL, BATTERY CURRENT COLLECTOR COMPRISING SAID ELECTROLYTIC COPPER FOIL, ELECTRODE OBTAINED USING SAID CURRENT COLLECTOR FOR SECONDARY BATTERY, AND SECONDARY BATTERY OBTAINED USING SAID ELECTRODE

摘要

There is provided an electrolytic copper foil having a tensile strength of 500 MPa or more as measured at room temperature after a heat treatment at 300 占 폚 for 1 hour. Also provided is an electrolytic copper foil having excellent mechanical strength in use in the field of a printed wiring board to be bonded to a polyimide film. Also disclosed is a current collector (copper foil) of a lithium ion secondary battery using a Si or Sn alloy-based active material, which maintains adhesion with an active material by a polyimide binder to provide a copper alloy foil which is not deformed or broken. 0.06 wt% to 0.5 wt% tungsten, and the balance copper. The electrolytic copper foil has a tensile strength of 500 MPa or more as measured at room temperature after a heat treatment at 300 캜 for 1 hour. Further, it is a secondary battery using the electrolytic copper foil as a current collector.