Aluminum alloy sheet for battery lids for molding integrated explosion-prevention valve, and method for producing same

Abstract

The invention provides an aluminum alloy sheet for battery lids that exhibits an excellent heat dissipation property, an excellent resistance to deformation, and an excellent moldability; and a method for producing the aluminum alloy sheet. The aluminum alloy sheet for battery lids enables the molding of an integrated explosion-prevention valve that exhibits little variability in operating pressure and an excellent cyclic fatigue resistance. The aluminum alloy sheet for battery lids for molding an integrated explosion-prevention valve is characterized by: a composition that contains Fe : 1.05-1.50 mass%, Mn : 0.30-0.70 mass%, Ti : 0.002-0.15 mass%, and B : less than 0.04 mass%, with the balance being Al and impurities, the Fe / Mn ratio being controlled to 1.8-3.5, wherein, as impurities, Si is controlled to less than 0.20 mass%, Cu is controlled to less than 0.03 mass%, Mg is controlled to less than 0.05 mass%, and V is controlled to less than 0.03 mass%; a conductivity of at least 53.0% IACS; a 0.2% proof stress of at least 40 MPa; an elongation value of at least 40%; the presence of a recrystallized microstructure; and both an elongation value after cold rolling at an 80% reduction ratio and an elongation value after cold rolling at a 90% reduction ratio both being at least 5.0%. The average crystal grain size of the recrystallized grains in the recrystallized microstructure is preferably 15-30 [mu]m.

Description

technical field [0001] The present invention relates to an aluminum alloy plate for a battery cover for forming an integral explosion-proof valve used in cylindrical and square 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 excellent ...

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.

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