Aluminum alloy plate for battery cover for forming integrated explosion-proof valve and manufacturing method thereof

Abstract

The present invention provides an aluminum alloy plate for a battery cover and a method for producing the same. The aluminum alloy plate for a battery cover is an aluminum alloy plate for a battery cover that has moderate strength and is excellent in formability and work softening property, and can be formed into variations in operating pressure. An integral explosion-proof valve that is small and has excellent resistance to repeated fatigue. An aluminum alloy plate for a battery cover for forming an integrated explosion-proof valve is characterized in that it has the following composition: 1.05 to 1.50 mass % of Fe, 0.15 to 0.70 mass % of Mn, 0.002 to 0.15 mass % of Ti, and less With 0.03% by mass of B, the rest is composed of Al and impurities, the Fe / Mn ratio is limited to 1.8 to 7.0, Si as impurities is limited to less than 0.40% by mass, Cu is limited to less than 0.03% by mass, and Mg is limited to less than 0.03% by mass. 0.05% by mass, V is limited to less than 0.03% by mass, the tensile strength is above 95MPa, the value of elongation is above 40%, has a recrystallized structure, and will be cold-rolled at a reduction rate of 70%. When the tensile strength is defined as TS70 and the tensile strength after cold rolling at a rolling reduction of 95% is defined as TS95, the value of (TS95-TS70) is less than -1MPa, after cold rolling at a rolling reduction of 90% The elongation value is above 5.0%. More preferably, the average grain size of the recrystallized grains of the recrystallized structure is 15 to 30 μm.

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.

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