Aluminum alloy foil for electrode current collectors and manufacturing method thereof

Abstract

It is an object to provide an aluminum alloy foil for an electrode current collector, the foil having a high post-drying strength after application of an active material while keeping a high electrical conductivity. Disclosed is an aluminum alloy foil for an electrode current collector, comprising 0.03 to 0.1 mass % (hereinafter, “mass %” is simply referred to as “%”) of Fe, 0.01 to 0.1% of Si, and 0.0001 to 0.01% of Cu, with the rest consisting of Al and unavoidable impurities, wherein the aluminum alloy foil after final cold rolling has a tensile strength of 180 MPa or higher, a 0.2% yield strength of 160 MPa or higher, and an electrical conductivity of 60% IACS or higher; and the aluminum alloy foil has a tensile strength of 170 MPa or higher and a 0.2% yield strength of 150 MPa or higher even after the aluminum alloy foil is subjected to heat treatment at any of 120° C. for 24 hours, 140° C. for 3 hours, and 160° C. for 15 minutes.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . A method for manufacturing the aluminum alloy foil for an electrode current collector, comprising:
 subjecting an aluminum alloy ingot comprising 0.03 to 0.1 mass % (hereinafter, “mass %” is simply referred to as “%”) of Fe, 0.01 to 0.1% of Si, and 0.0001 to 0.01% of Cu, with the rest being of Al and unavoidable impurities to homogenizing treatment at 550 to 620° C. for 1 to 20 hours; and   performing hot rolling at a starting temperature of 500° C. or higher and at an end-point temperature of 255 to 300° C.   
     
     
         2 . The method of  claim 1 , wherein in the hot rolling, a time going through a temperature range from 350 to 500° C. is within 20 minutes. 
     
     
         3 . The method of  claim 1 , wherein the end-point temperature of the hot rolling is 255 to 285° C.