Aluminum alloy plate for battery lid for use in molding of integral explosion-proof valve, and method for producing same

Abstract

Provided are: an aluminum alloy plate for a battery lid, which has proper strength and has excellent heat-dissipating properties, moldability and properties to be softened upon processing, and which enables the molding of an integral explosion-proof valve showing small variations in operating pressure and having excellent repeated fatigue resistance properties; and a method for producing the aluminum alloy plate. An aluminum alloy plate for a battery lid for use in the molding of an integral explosion-proof valve, the aluminum alloy plate being characterized by having a component composition comprising 1.05 to 1.50% by mass of Fe, 0.15 to 0.70% by mass of Mn, 0.002 to 0.15% by mass of Ti, less than 0.05% by mass of B and a remainder made up by Al and impurities, wherein the Fe / Mn ratio isadjusted to 1.8 to 7.0, the contents of Si, Cu, Mg and V that are contained as impurities are adjusted to less than 0.40% by mass, less than 0.03% by mass, less than 0.05% by mass and less than 0.03%by mass, respectively, and also characterized by having tensile strength of 95 MPa or more and an elongation value of 40% or more, and having a recrystallized structure, wherein, the (TS95 - TS90) value is less than -4 MPa when the tensile strength measured after being subjected to a cold-rolling procedure at a rolling reduction rate of 90% is defined as TS90 and the tensile strength measured after being subjected to a cold-rolling procedure at a rolling reduction rate of 95% is defined as TS95, and the elongation value measured after being subjected to a cold-rolling procedure at a rolling reduction rate of 90% is 5.0% or more. It is preferred that the average crystal grain diameter of recrystallized grains in the recrystallized structure is 15 to 30 um.

Description

technical field [0001] The present invention relates to an aluminum alloy plate for a battery cover for forming an integrated explosion-proof valve used in square, cylindrical and other lithium-ion batteries and having a small working pressure deviation. Background technique [0002] In recent years, countries have imposed stricter regulations on automobile exhaust, and the production of electric vehicles, which are environmentally friendly vehicles, is rapidly expanding. Currently, the mainstream of secondary batteries used in electric vehicles is lithium-ion batteries. Lithium-ion battery casings come in various types such as square, cylindrical, and sheet-shaped. In the case of square and cylindrical shapes, aluminum alloy plates that can achieve weight reduction are drawn and processed. Or a shell obtained by thinning and deep drawing processing (also called DI processing). [0003] Thus, as a material for a battery case, development of an aluminum alloy plate having e...

AI Technical Summary

Problems solved by technology

The explosion-proof valve must work reliably, and the valve will automatically break when the internal pressure of the container exceeds the specified pressure, etc.

Images