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CN-122003511-A - Aluminum-based alloy and product thereof

CN122003511ACN 122003511 ACN122003511 ACN 122003511ACN-122003511-A

Abstract

The invention relates to the field of metallurgy, in particular to an aluminum alloy for manufacturing a thin aluminum foil for a lithium ion battery and a battery pack thereof. The aluminum alloy comprises 0.40-0.60 wt% of iron, 0.10-0.20 wt% of silicon, 0.05-0.15 wt% of copper, 0.05-0.10 wt% of zirconium, 0.01-0.05 wt% of scandium, 0.005-0.02 wt% of titanium, 0.0001-0.005 wt% of boron, not less than 99.0 wt% of aluminum, unavoidable impurities including not more than 0.02 wt% of vanadium, and the balance. Nano-dispersed precipitates of Al 3 Sc、Al 3 Zr phase having an L1 2 type crystal structure, and a composite phase Al 3 (Sc, zr) exist in the microstructure of the alloy. In a second embodiment, the alloy additionally contains an element selected from the group consisting of manganese not more than 0.15 wt% and nickel not more than 0.15 wt%. The invention realizes that the ultimate tensile strength is improved to 265-305 megapascals and the elongation at break is improved to 2% -3%.

Inventors

  • Victor Christianovich Mann
  • Dmitry Konstantinovich Liabov
  • Roman Olegovich Vakoromov
  • Alexander. Yuryevich Gradopov
  • Ruslan Tehmurovich Aliyev
  • Yevgeny Vasilyevich Shenkalenko
  • Yevgenya Vladimir Rovna Krivenkova

Assignees

  • 轻材料与技术研究所有限责任公司

Dates

Publication Date
20260508
Application Date
20241001
Priority Date
20231011

Claims (4)

  1. 1. An aluminum alloy for manufacturing a thin aluminum foil for lithium ion batteries, which contains iron, silicon, copper, scandium, titanium, boron, aluminum and unavoidable impurities, characterized by further containing zirconium, and having the following composition in weight percent: 0.40 to 0.60 percent of iron; 0.10 to 0.20 percent of silicon; 0.05 to 0.15 percent of copper; 0.05 to 0.10 percent of zirconium; scandium 0.01-0.05; 0.005-0.02 of titanium; Boron is 0.0001-0.005; aluminum not less than 99.0; Unavoidable impurities including vanadium, the balance being aluminum and unavoidable impurities, wherein the content of vanadium is not more than 0.02 wt.%, and nano-dispersed precipitates of Al 3 Sc phase and Al 3 Zr phase having an L1 2 type crystal lattice, and complex phase Al 3 (Sc, zr) are present in the microstructure of the alloy.
  2. 2. An aluminum alloy for manufacturing a thin aluminum foil for lithium ion batteries, which contains iron, silicon, copper, scandium, titanium, boron, aluminum and unavoidable impurities, characterized by further containing zirconium and at least one element selected from the group consisting of manganese, nickel, and having the following components in weight percent: 0.40 to 0.60 percent of iron; 0.10 to 0.20 percent of silicon; 0.05 to 0.15 percent of copper; 0.05 to 0.10 percent of zirconium; scandium 0.01-0.05; 0.005-0.02 of titanium; Boron is 0.0001-0.005; manganese not more than 0.15; Nickel not exceeding 0.15; aluminum not less than 99.0; Unavoidable impurities including vanadium, the balance being aluminum and unavoidable impurities, wherein the content of vanadium is not more than 0.02 wt.%, and nano-dispersed precipitates of Al 3 Sc phase and Al 3 Zr phase having an L1 2 type crystal lattice, and complex phase Al 3 (Sc, zr) are present in the microstructure of the alloy.
  3. 3. An article made from the aluminum alloy of claim 1 or 2, in the form of an aluminum foil having an ultimate tensile strength of not less than 265 mpa and an elongation at break of not less than 2%.
  4. 4. The article of claim 3, wherein the aluminum foil has a thickness of less than 12 microns.

Description

Aluminum-based alloy and product thereof Technical Field The invention belongs to the field of nonferrous metal metallurgy, and particularly relates to an aluminum alloy for manufacturing a thin aluminum foil for a lithium ion battery electrode. Background Aluminum foil is one of the main materials for manufacturing lithium ion batteries, which are composed of an ultrathin aluminum foil layer coated with a lithium-containing positive electrode material and a copper foil with a negative electrode layer. The improvement of the energy density of the battery can be achieved by increasing the number of layers and the surface area per unit volume, and thus further reduction of the aluminum foil thickness is required. In the last few years, the thickness of the aluminium foil used has been reduced from 16 to 14 microns and subsequently to 12 microns. Currently, many battery manufacturers are turning to the use of aluminum foil having a thickness of 10 microns or even 8 microns. As the aluminum foil for lithium ion batteries becomes thinner, the requirements for the ultimate tensile strength and surface quality are increased in proportion. To avoid breakage during the process of coating the positive electrode material layer, calendaring, rolling, drying, and other processes that subject the aluminum foil to tensile and compressive forces, the material must have sufficient strength and plasticity. For aluminum foils having a thickness of 10 microns and less, a strength level of not less than 265 mpa and an elongation of not less than 2% are required. Currently, aluminum foils for lithium ion batteries are manufactured from 1xxx series industry pure aluminum grades (e.g., 1070, 1235, 1200, 1100) having aluminum contents of not less than 99.0 wt.%. The tensile strength in the H18 work hardened state is about 180 to 200 megapascals. WO2019124530 discloses an aluminum alloy for aluminum foil, which contains (by weight) Fe 1.0-1.8, si 0.01-0.06, cu 0.006-0.015, and the balance of aluminum and unavoidable impurities. The composition can obtain aluminum foil for battery electrode with thickness of 6-30 μm and tensile strength of up to 180 megaPa. The disadvantage of this solution is that the strength performance level is insufficient for thin aluminium foils. WO2014069119 discloses an alloy for manufacturing aluminium foil for lithium ion batteries. The alloy contains (by weight) Fe 0.2-1.0, si 0.1-0.6, and balance Al and unavoidable impurities. Variations of this composition are also known, wherein an additional alloying addition of Cu 0.01-0.25 wt-%. A method of making aluminum foil 12 microns thick from the alloy is also described. The strength of the aluminum foil prepared from the alloy is 210 megapascals, which is slightly higher than that of the similar products, but the aluminum foil is still insufficient for thin aluminum foil. JP5639398 discloses a reinforced alloy for manufacturing a contact (three-phase slip ring). The alloy contains (by weight) Fe 0.2-1.3, cu 0.01-0.5, si not more than 0.2, and unavoidable impurities, with the balance being not less than 88.0% by weight. According to the patent specification, aluminum foil for battery contact (three-phase slip ring) with thickness of 5-20 micrometers, ultimate tensile strength of 215-220 megapascals and elongation of 1% -3% can be manufactured from the composition. Although the strength properties of the aluminum foil of this aluminum alloy solution are higher than those of the similar products, it is still insufficient for a thin aluminum foil used as an electrode of a battery. The high content of alloying elements (particularly copper) results in a low residual aluminum content, making the alloy less suitable for manufacturing aluminum foils for thin batteries, which are manufactured mainly from 1 xxx-series alloys having an aluminum content of not less than 99.0 wt.%. One of the 1xxx series alloys widely used for manufacturing aluminum foils for batteries is 1100 alloy, which contains (wt%) Fe+Si total amount of not more than 0.95, cu 0.05-0.20, mn of not more than 0.05, zn of not more than 0.10, each other impurity alone of not more than 0.05, and the balance Al content of not less than 99.0% according to GOST 618-2014 aluminum foil for technology. Thin aluminum foils with a thickness of less than 10 μm can be obtained with this alloy, with an ultimate tensile strength of up to 245 mpa (standard GB/T33143 aluminium and aluminum foil for lithium ion batteries). However, to produce thin aluminum foils with higher mechanical property levels, it is necessary to re-examine the composition of the alloy. As a closest prior art (prototype) the solution selected is the alloy described in WO2019214243 "1100 alloy aluminum foil for lithium batteries and method for manufacturing same", which proposes an aluminum foil for lithium batteries based on 1100 alloy, comprising the following components in weight-%: Fe:0.4-0.5; Si:0.1-0.2; Cu:0.1-0.15; Ti:0.01-0.02; Sc:0.03-0.