Aluminium alloy plate, making method and aluminium alloy made cell box

Abstract

The aluminum alloy sheet is composed of aluminum alloy containing, by mass%, 0.9-1.5% Mn, >0.50-1.0% Cu, 0.2-0.6% Mg, 0.05-0.50% Si, 0.05-0.60% Fe, Zn regulated to <=0.10% and the balance Al with inevitable impurities. In this manner, this invention provides an aluminum alloy sheet for a battery case which is excellent in strength, formability, laser weldability, stress relaxation property and pressure resistance (bulging resistance) even when the sheet thickness is reduced, and to provide a production method therefor.

Description

technical field [0001] The present invention relates to an aluminum alloy plate suitable for a battery case such as a lithium ion secondary battery case, and a battery case composed of the aluminum alloy plate. Background technique [0002] Conventionally, lithium-ion secondary battery packs (hereinafter referred to as battery packs) mounted as power sources for mobile phones, portable personal computers, etc. have been used for the purpose of miniaturization and weight reduction. and strong aluminum alloy. [0003] However, in such a battery case, when the battery is charged and discharged, the pressure inside the battery case increases. In addition, in summer, when an electronic device equipped with such a battery case is placed in a high-temperature environment such as a car for a long time, the battery case itself even reaches 60 to 90°C, and the pressure inside the battery case rises significantly. The internal stress of the material itself used for the battery case w...

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Problems solved by technology

[0008] However, since the Cu content of the Al alloy material (the aluminum alloy plate for the battery case in the present invention) of JP-A-10-284014 is more than 0.20wt%, 0.5wt% or less (wt% and the mass of the present invention % synonymous) and low, so the strength is not sufficient, in addition, can not suppress the stress relaxation phenomenon

As a result, the sealed rectangular lithium-ion secondary battery outer case (battery case in the present invention) made of this aluminum alloy material cannot suppress the expansion of the outer case when the internal pressure of the outer case increases due to temperature rise.

[0009] In addition, since the Mg content of the aluminum alloy plate for secondary battery case (the aluminum alloy plate for battery case in the present invention) of JP-A-2000-129384 is 0.20% by weight or less (% by weight is equal to the mass of the present invention), % synonymous) and low, so the strength is not sufficient, in addition, can not suppress the stress relaxation phenomenon

As a result, the battery case made of the aluminum alloy plate for secondary battery cases cannot suppress the expansion of the battery case when the internal pressure of the battery case increases due to temperature rise.

[0010] In addition, since the Zn content of the aluminum alloy plate for a secondary battery case in JP-A-2003-34833 is as high as 0.2 to 0.7% by weight, Zn will scatter during welding and pollute the surrounding environment.

Therefore, such an aluminum alloy plate for a secondary battery case has poor laser weldability when producing a battery case.

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