ELECTROLYTIC COPPER ALLOY FOIL, METHOD FOR PRODUCING SAME, ELECTROLYTIC SOLUTION USED FOR PRODUCTION OF SAME, NEGATIVE ELECTRODE COLLECTOR FOR SECONDARY BATTERIES USING SAME, SECONDARY BATTERY, AND ELECTRODE OF SECONDARY BATTERY

摘要

Provided is an electrolytic copper alloy foil which has high mechanical strength in a normal state and is not susceptible to thermal deterioration even if heated to 300°C or higher. This electrolytic copper foil is an electrolytic copper alloy foil that contains tungsten with the balance made up of copper. Preferably, the electrolytic copper foil takes in tungsten into the copper foil in the form of a copper alloy, and has a tensile strength at normal temperature of 650 MPa or more, a tensile strength after a heat treatment at 300°C for one hour of 450 MPa or more, and an electrical conductivity of 80% or more. More preferably, the electrolytic copper foil has an elongation at normal temperature of 2.5% or more and an elongation after a heat treatment at 300°C for one hour of 3.5% or more. This electrolytic copper foil is produced through electrolytic deposition by adding a thiourea compound, a tungsten salt and chloride ions into a sulfuric acid-copper sulfate electrolytic solution.