A corrosion-resistant aluminum alloy sheet for batteries and its preparation process

Abstract

This invention discloses a corrosion-resistant aluminum alloy sheet for batteries and its preparation process, belonging to the field of aluminum alloy processing technology. The corrosion-resistant aluminum alloy sheet for batteries comprises a corrosion-resistant layer, a load-bearing layer, and a protective layer stacked sequentially. The corrosion-resistant layer comprises Si 1-3 wt%, Mg 0.2-1 wt%, Fe 0.05-0.2 wt%, Cu 0.01-0.2 wt%, with the balance being Al and unavoidable impurities. The load-bearing layer comprises Sc 0.08-0.25 wt%, Zr 0.01-0.1 wt%, Si 0.2-1 wt%, Mn 0.1-0.5 wt%, with the balance being Al and unavoidable impurities. The protective layer comprises Zn 4-8 wt%, Ga 0.006-0.02 wt%, Mg 0.05-0.5 wt%, Ti 0.01-0.1 wt%, with the balance being Al and unavoidable impurities. This invention adds Sc and Ga to form an Al3Sc nanophase and a dense Ga2O3-Al2O3 composite oxide film, thereby increasing the grain boundary corrosion potential and suppressing local galvanic corrosion. In addition, the three-layer alloy structure achieves corrosion resistance, strong support and self-protection functions, thus extending the service life of the battery.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy processing technology, specifically relating to a corrosion-resistant aluminum alloy sheet for batteries and its preparation process. Background Technology

[0002] With the rapid development of new energy vehicles and electronic devices, the performance requirements for battery materials are becoming increasingly stringent. Aluminum alloy sheets for batteries need to possess excellent corrosion resistance, mechanical properties, and machinability to meet the needs of components such as battery casings and battery packs.

[0003] Traditional aluminum alloys have limitations in terms of corrosion resistance and mechanical properties. Aluminum alloys generally suffer from a trade-off between high strength and high corrosion resistance; higher strength often results in lower corrosion resistance. High-strength aluminum alloys typically require the addition of numerous alloying elements, which, while increasing strength, also increase the material's electrochemical activity, thus reducing corrosion resistance. Cold-rolled aluminum alloy sheets are prone to exfoliation corrosion. The fibrous structure formed during cold rolling exhibits a tendency for intergranular corrosion, with corrosion progressing along the grain boundaries in the rolling direction. The resulting corrosion products expand in volume, causing blistering on the alloy surface, and in severe cases, leading to layered prying or peeling off. Furthermore, traditional aluminum alloy surface treatment processes (such as phosphating) also have limitations. For example, the quality of the phosphating film significantly affects the corrosion resistance and coating adhesion of the aluminum alloy; however, excessively thick or thin phosphating films can lead to decreased corrosion resistance. These defects limit the application of aluminum alloys in harsh environments such as high humidity and high salt spray conditions. Therefore, finding a new type of aluminum alloy sheet with corrosion resistance is essential. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a corrosion-resistant aluminum alloy sheet for batteries and its preparation process.

[0005] The first aspect of the present invention is to provide a corrosion-resistant aluminum alloy sheet for batteries, comprising an anti-corrosion layer, a load-bearing layer and a protective layer stacked sequentially;

[0006] The anti-corrosion layer comprises 1-3 wt% Si, 0.2-1 wt% Mg, 0.05-0.2 wt% Fe, and 0.01-0.2 wt% Cu, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%.

[0007] The supporting layer comprises 0.08-0.25 wt% Sc, 0.01-0.1 wt% Zr, 0.2-1 wt% Si, and 0.1-0.5 wt% Mn, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0008] The protective layer comprises 4-8 wt% Zn, 0.006-0.02 wt% Ga, 0.05-0.5 wt% Mg, and 0.01-0.1 wt% Ti, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0009] In some embodiments, the anti-corrosion layer comprises 1.5-2 wt% Si, 0.5-0.8 wt% Mg, 0.1-0.15 wt% Fe, and 0.01-0.1 wt% Cu, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%.

[0010] The supporting layer comprises 0.12-0.18 wt% Sc, 0.04-0.08 wt% Zr, 0.4-0.6 wt% Si, and 0.1-0.3 wt% Mn, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0011] The protective layer comprises 6-7.5 wt% Zn, 0.008-0.015 wt% Ga, 0.1-0.3 wt% Mg, and 0.01-0.03 wt% Ti, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0012] A second aspect of this invention is to provide a process for preparing corrosion-resistant aluminum alloy sheets for batteries, comprising the following steps:

[0013] S1: Melt and cast the anti-corrosion layer, load-bearing layer and protective layer according to the component ratios respectively;

[0014] S2: Micro-arc etching is performed on the surfaces of the anti-corrosion layer, the load-bearing layer, and the protective layer to form a rough interface;

[0015] S3: The anti-corrosion layer, the load-bearing layer and the protective layer, which have been micro-arc etched, are stacked in order from top to bottom and placed in a rolling mill for three hot rolling passes to obtain aluminum alloy sheet.

[0016] S4: The aluminum alloy sheet is subjected to solution treatment, quenching, and two-stage aging strengthening.

[0017] S5: The aluminum alloy sheet treated with S4 is placed in an electrolyte and subjected to an electrolytic plasma oxidation reaction. After the edges are sealed, a corrosion-resistant aluminum alloy sheet for batteries is obtained.

[0018] In some implementations, the anti-corrosion layer has a thickness of 8-12 mm, the load-bearing layer has a thickness of 14-16 mm, and the protective layer has a thickness of 8-12 mm.

[0019] In some implementations, the melting temperature is 660-750°C, argon gas is introduced during the melting of the anti-corrosion layer, and the support layer is melted under vacuum.

[0020] In some implementations, micro-arc etching forms a rough interface 45-55 μm deep on the surface of the alloy layer.

[0021] In some embodiments, the conditions for the three-pass hot rolling are as follows: first pass: 55-65% compression at 400-450°C, second pass: 35-45% compression at 300-400°C, and last pass: 15-25% compression at 200-300°C.

[0022] In this invention, a three-pass hot rolling process is adopted. In the first pass, the interlayer etching microgrooves are etched under high temperature and high pressure to produce a local melting effect, which stimulates the diffusion of aluminum atoms across the interface and establishes a preliminary metallurgical bond. In the second pass, medium temperature and medium pressure induce grain boundary migration and recrystallize under the synergy of Sc / Zr elements, which enhances the potential for subsequent aging strengthening. In the final pass, low temperature and light pressure are used to eliminate interlayer thermal stress and strengthen the base surface structure.

[0023] In some embodiments, solution treatment and quenching specifically involve raising the aluminum alloy sheet to 500-520°C at a rate of 10-15°C / min, holding it at that temperature for 50-70 min, and then quenching it using high-pressure water mist. The two-stage aging strengthening includes primary aging and secondary aging. Primary aging involves placing the aluminum alloy sheet at 115-125°C for 7-9 h, while secondary aging refers to raising the temperature of the aluminum alloy sheet to 155-165°C within 8-12 min.

[0024] It should be noted that this invention creatively employs a staged temperature-controlled nanophase precipitation process. The first stage involves long-term low-temperature aging to form high-density Mg-Si-Cu aggregates, which strengthens the support of the plate. At the same time, the low temperature drives Fe / Mn impurity atoms to migrate into the grains, significantly reducing grain boundary segregation and lowering the grain boundary corrosion current. The second stage involves short-term high-temperature aging to accelerate Sc / Zr diffusion and excite the Al3(Sc,Zr) nanophase, avoiding excessive diffusion of Zn / Ga. When corrosion perforates, Zn can preferentially act as the anode to react, preventing further corrosion spread.

[0025] In some embodiments, the electrolyte is a mixture of sodium silicate, ammonium molybdate, and trisodium citrate in a mass ratio of 15-17:1:1-3.

[0026] It should be noted that this invention uses a novel electrolyte formulation, employing ammonium molybdate ((NH4)2MoO4) as a corrosion inhibitor. The aluminum alloy sheet adsorbs MoO4 through micropores. 2- When ions encounter HF, they can be transformed into a MoO2F2 passivation film, blocking fluoride ion corrosion; sodium silicate forms a nano-SiO2 sealing layer, which can prevent electrolyte penetration.

[0027] In some embodiments, during the electrolytic plasma oxidation reaction, the anode is an S4-treated plate, the cathode is a stainless steel plate, the voltage is 250-300V, and the current density is 4.5-5.5A / dm³. 2 The reaction time is 8-10 min.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention creatively incorporates Sc into the load-bearing layer of an aluminum alloy sheet and Ga into the protective layer. Sc can form an Al3Sc nanophase with metallic aluminum, thus blocking Cl. - F - The corrosion of the substrate increases the grain boundary corrosion potential; Ga can promote the formation of a dense Ga2O3-Al2O3 composite oxide film on the surface, improve the ionic conductivity of the oxide film, and inhibit local galvanic corrosion. In addition, the three-layer structure adopted in this invention has the protective functions of corrosion resistance, high pressure resistance, and self-repair. The corrosion-resistant layer can generate an amorphous SiO2 passivation film to play a role in corrosion resistance; the bearing layer has a Sc-Zr reinforced matrix, which provides mechanical support to improve mechanical properties and thus reduce plate deformation; the protective layer has a high content of Zn and Ga, which can preferentially dissolve when damaged, actively protecting the matrix from corrosion.

[0030] This invention achieves atomic-level metallurgical bonding between layers through etching and hot rolling technology, avoiding the problem of interface delamination in composite materials. A dual-stage aging strengthening technology simultaneously improves both matrix strength and grain boundary corrosion resistance, overcoming the contradiction between high strength and high corrosion. Electrolytic plasma oxidation technology constructs a self-healing microporous film layer on the surface, effectively blocking hydrogen fluoride corrosion from the electrolyte. These three technologies synergistically form a stable system of strong matrix and strong protection, extending the battery's service life under extreme operating conditions. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments.

[0032] Example 1

[0033] A corrosion-resistant aluminum alloy sheet for batteries includes a corrosion-resistant layer, a load-bearing layer, and a protective layer stacked sequentially.

[0034] The anti-corrosion layer comprises 1.8 wt% Si, 0.7 wt% Mg, 0.12 wt% Fe, and 0.05 wt% Cu, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%.

[0035] The supporting layer comprises 0.15 wt% Sc, 0.06 wt% Zr, 0.5 wt% Si, and 0.2 wt% Mn, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0036] The protective layer comprises 6.5 wt% Zn, 0.012 wt% Ga, 0.2 wt% Mg, and 0.02 wt% Ti, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0037] The corrosion-resistant aluminum alloy sheet for batteries described above is prepared by the following steps:

[0038] S1: The components are melted according to their proportions. The anti-corrosion layer is melted and cast into an alloy ingot with a thickness of 10 mm under argon protection at 720°C. The bearing layer is cast into an alloy ingot with a thickness of 15 mm under vacuum at 740°C. The protective layer is cast into an alloy ingot with a thickness of 10 mm at 660°C.

[0039] S2: Micro-arc etching is performed on the surfaces of the anti-corrosion layer, the load-bearing layer and the protective layer to form a 50 μm deep rough interface;

[0040] S3: The anti-corrosion layer, load-bearing layer, and protective layer, which have undergone micro-arc etching, are stacked in a top-to-bottom order and placed in a rolling mill for three passes of hot rolling to obtain aluminum alloy sheet; wherein, the first pass: 60% compression at 450℃, the second pass: 40% compression at 350℃, and the last pass: 20% compression at 250℃;

[0041] S4: The hot-rolled aluminum alloy sheet is solution-treated and quenched, heated to 510℃ at 15℃ / min and held for 60min; then a two-stage aging strengthening treatment is carried out. First stage aging: the sheet is held at 120℃ for 8 hours. Second stage aging: the sheet temperature is raised to 160℃ within 10min.

[0042] S5: The S4-treated aluminum alloy sheet is placed in an electrolyte solution composed of sodium silicate, ammonium molybdate, and trisodium citrate in a mass ratio of 16:1:2 for electrolytic plasma oxidation. The anode is the S4-treated sheet, the cathode is a stainless steel plate, the voltage is 300 V, and the current density is 5 A / dm³. 2 The reaction time is 10 minutes, and the corrosion-resistant aluminum alloy sheet for batteries is obtained after edge sealing.

[0043] Example 2

[0044] A corrosion-resistant aluminum alloy sheet for batteries includes a corrosion-resistant layer, a load-bearing layer, and a protective layer stacked sequentially.

[0045] The anti-corrosion layer comprises 2 wt% Si, 0.8 wt% Mg, 0.15 wt% Fe, and 0.1 wt% Cu, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%.

[0046] The supporting layer comprises 0.18 wt% Sc, 0.08 wt% Zr, 0.6 wt% Si, and 0.3 wt% Mn, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0047] The protective layer comprises 7.5 wt% Zn, 0.015 wt% Ga, 0.3 wt% Mg, and 0.03 wt% Ti, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0048] The corrosion-resistant aluminum alloy sheet for batteries described above is prepared by the following steps:

[0049] S1: The components are melted according to their proportions. The anti-corrosion layer is melted and cast into an alloy ingot with a thickness of 12 mm under argon protection at 720°C. The bearing layer is cast into an alloy ingot with a thickness of 116 mm under vacuum at 740°C. The protective layer is cast into an alloy ingot with a thickness of 12 mm at 660°C.

[0050] S2: Micro-arc etching is performed on the surfaces of the anti-corrosion layer, the load-bearing layer and the protective layer to form a 55 μm deep rough interface;

[0051] S3: The anti-corrosion layer, load-bearing layer, and protective layer, which have undergone micro-arc etching, are stacked in a top-to-bottom order and placed in a rolling mill for three passes of hot rolling to obtain aluminum alloy sheet; wherein, the first pass: 65% compression at 450℃, the second pass: 45% compression at 400℃, and the last pass: 25% compression at 300℃;

[0052] S4: The hot-rolled aluminum alloy sheet is solution-treated and quenched, heated to 520℃ at 15℃ / min and held for 70min; then a two-stage aging strengthening treatment is carried out. First stage aging: the sheet is held at 125℃ for 9 h. Second stage aging: the sheet temperature is raised to 165℃ within 12 min.

[0053] S5: The S4-treated aluminum alloy sheet is placed in an electrolyte solution composed of sodium silicate, ammonium molybdate, and trisodium citrate in a mass ratio of 17:1:3 for electrolytic plasma oxidation. The anode is the S4-treated sheet, the cathode is a stainless steel plate, the voltage is 300V, and the current density is 5.5A / dm³. 2 The reaction time is 10 minutes, and the corrosion-resistant aluminum alloy sheet for batteries is obtained after edge sealing.

[0054] Example 3

[0055] A corrosion-resistant aluminum alloy sheet for batteries includes a corrosion-resistant layer, a load-bearing layer, and a protective layer stacked sequentially.

[0056] The anti-corrosion layer comprises 1.5 wt% Si, 0.5 wt% Mg, 0.1 wt% Fe, and 0.01 wt% Cu, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%.

[0057] The supporting layer comprises 0.12 wt% Sc, 0.04 wt% Zr, 0.4 wt% Si, and 0.1 wt% Mn, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0058] The protective layer consists of 6 wt% Zn, 0.008 wt% Ga, 0.1 wt% Mg, and 0.01 wt% Ti, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0059] The corrosion-resistant aluminum alloy sheet for batteries described above is prepared by the following steps:

[0060] S1: The components are melted separately according to their proportions. The anti-corrosion layer is melted and cast into an alloy ingot with a thickness of 8 mm under argon protection at 720°C. The bearing layer is cast into an alloy ingot with a thickness of 14 mm under vacuum at 740°C. The protective layer is cast into an alloy ingot with a thickness of 8 mm at 660°C.

[0061] S2: Micro-arc etching is performed on the surfaces of the anti-corrosion layer, the load-bearing layer and the protective layer to form a 45 μm deep rough interface;

[0062] S3: The anti-corrosion layer, the load-bearing layer, and the protective layer, which have undergone micro-arc etching, are stacked in a top-to-bottom order and placed in a rolling mill for three passes of hot rolling to obtain aluminum alloy sheet; wherein, the first pass: 55% compression at 400℃, the second pass: 35% compression at 300℃, and the last pass: 15% compression at 200℃.

[0063] S4: The hot-rolled aluminum alloy sheet is solution-treated and quenched, heated to 500℃ at 10℃ / min and held for 50min; then a two-stage aging strengthening treatment is carried out. First stage aging: the sheet is held at 115℃ for 7 h. Second stage aging: the sheet temperature is raised to 155℃ within 8 min.

[0064] S5: The S4-treated aluminum alloy sheet is placed in an electrolyte solution composed of sodium silicate, ammonium molybdate, and trisodium citrate in a mass ratio of 15:1:1 for electrolytic plasma oxidation. The anode is the S4-treated sheet, the cathode is a stainless steel plate, the voltage is 250V, and the current density is 4.5A / dm³. 2 The reaction time is 8 minutes, and the corrosion-resistant aluminum alloy sheet for batteries is obtained after edge sealing.

[0065] Example 4

[0066] It is basically the same as Example 1, except that:

[0067] The anti-corrosion layer, load-bearing layer, and protective layer components of the corrosion-resistant aluminum alloy sheet for batteries provided in this embodiment are as follows:

[0068] The corrosion-resistant layer comprises 3 wt% Si, 1 wt% Mg, 0.2 wt% Fe, and 0.2 wt% Cu, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%.

[0069] The supporting layer comprises 0.25 wt% Sc, 0.1 wt% Zr, 1 wt% Si, and 0.5 wt% Mn, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0070] The protective layer consists of 8 wt% Zn, 0.02 wt% Ga, 0.5 wt% Mg, and 0.1 wt% Ti, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0071] Example 5

[0072] It is basically the same as Example 1, except that:

[0073] The anti-corrosion layer, load-bearing layer, and protective layer components of the corrosion-resistant aluminum alloy sheet for batteries provided in this embodiment are as follows:

[0074] The corrosion-resistant layer comprises 1 wt% Si, 0.2 wt% Mg, 0.05 wt% Fe, and 0.01 wt% Cu, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%.

[0075] The supporting layer comprises 0.08 wt% Sc, 0.01 wt% Zr, 0.2 wt% Si, and 0.1 wt% Mn, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0076] The protective layer consists of 4 wt% Zn, 0.006 wt% Ga, 0.05 wt% Mg, and 0.01 wt% Ti, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0077] Comparative Example 1

[0078] It is basically the same as Example 1, except that Sc is replaced with the same amount of Y.

[0079] Comparative Example 2

[0080] It is basically the same as Example 1, except that Ga is replaced with the same amount of In.

[0081] Comparative Example 3

[0082] The process is essentially the same as in Example 1, except that a single-layer structure is used. The chemical composition of the three-layer alloy is smelted into a 35 mm thick single-layer homogeneous alloy. The elemental composition is calculated as the sum of the three layers. The aluminum alloy sheet composition is as follows: Si 2.3 wt%, Mg 0.9 wt%, Fe 0.12 wt%, Cu 0.05 wt%, Sc 0.15 wt%, Zr 0.06 wt%, Mn 0.2 wt%, Zn 6.5 wt%, Ga 0.012 wt%, Ti 0.02 wt%, with the balance being Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15 wt%.

[0083] Comparative Example 4

[0084] It is basically the same as Example 1, except that the three-pass hot rolling is replaced with a single hot rolling, that is, the hot rolling condition is 81% compression at 400°C.

[0085] Comparative Example 5

[0086] It is basically the same as Example 1, except that the two-stage aging strengthening is replaced with single-stage aging strengthening, that is, the aluminum alloy sheet is kept at 160°C for 10 hours.

[0087] Comparative Example 6

[0088] It is basically the same as Example 1, except that electrolytic plasma oxidation is replaced with ordinary anodizing.

[0089] To demonstrate that the corrosion-resistant aluminum alloy sheet for batteries provided by this invention has excellent mechanical properties and corrosion resistance, performance tests were conducted on Examples 1-5 and Comparative Examples 1-6, and the test results are shown in Table 1.

[0090] Mechanical property testing: The rectangular standard specimen with gauge length P001 model was used for testing. The sampling direction was parallel to the rolling direction, and the test was carried out according to the room temperature tensile method of GB / T 228.1.

[0091] Intergranular corrosion resistance test: ASTM G67-2018, 500-hour test.

[0092] Resistance to exfoliation corrosion test: Refer to GB / T 22639-2022.

[0093] Table 1

[0094]

[0095] As can be seen from Table 1, the corrosion-resistant aluminum alloy sheet for batteries provided in the embodiments of the present invention has both excellent mechanical properties and high corrosion resistance, and the intergranular corrosion rate is relatively slow. In contrast, the mechanical properties and corrosion resistance of each comparative example are weaker. Comparative examples 1 and 2 replace Sc with Y and Ga with In, respectively, which leads to a decrease in the mechanical properties and corrosion resistance of the sheet. This shows that Sc and Ga are irreplaceable in the present invention. Comparative examples 3-6 adopt a single-layer alloy structure, single-pass hot rolling, single-stage aging strengthening and ordinary anodizing, respectively, which leads to a significant decrease in the various properties of the aluminum alloy sheet.

[0096] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A corrosion-resistant aluminum alloy sheet for batteries, characterized in that, It includes a corrosion-resistant layer, a load-bearing layer, and a protective layer stacked in sequence; The anti-corrosion layer comprises 1-3 wt% Si, 0.2-1 wt% Mg, 0.05-0.2 wt% Fe, and 0.01-0.2 wt% Cu, with the balance being Al and unavoidable impurities; the total content of the unavoidable impurities is ≤0.2 wt%. The supporting layer comprises 0.08-0.25 wt% Sc, 0.01-0.1 wt% Zr, 0.2-1 wt% Si, and 0.1-0.5 wt% Mn, with the balance being Al and unavoidable impurities; the total content of the unavoidable impurities is ≤0.15 wt%. The protective layer comprises 4-8 wt% Zn, 0.006-0.02 wt% Ga, 0.05-0.5 wt% Mg, and 0.01-0.1 wt% Ti, with the balance being Al and unavoidable impurities; the total content of the unavoidable impurities is ≤0.15 wt%.

2. The corrosion-resistant aluminum alloy sheet for batteries according to claim 1, characterized in that, The anti-corrosion layer comprises 1.5-2 wt% Si, 0.5-0.8 wt% Mg, 0.1-0.15 wt% Fe, and 0.01-0.1 wt% Cu, with the balance being Al and unavoidable impurities; the total content of the unavoidable impurities is ≤0.2 wt%. The supporting layer comprises 0.12-0.18 wt% Sc, 0.04-0.08 wt% Zr, 0.4-0.6 wt% Si, and 0.1-0.3 wt% Mn, with the balance being Al and unavoidable impurities; the total content of the unavoidable impurities is ≤0.15 wt%. The protective layer comprises 6-7.5 wt% Zn, 0.008-0.015 wt% Ga, 0.1-0.3 wt% Mg, and 0.01-0.03 wt% Ti, with the balance being Al and unavoidable impurities; the total content of the unavoidable impurities is ≤0.15 wt%.

3. A process for preparing the corrosion-resistant aluminum alloy sheet for batteries as described in claim 1 or 2, characterized in that, Includes the following steps: S1: Melt and cast the anti-corrosion layer, load-bearing layer and protective layer according to the component ratios respectively; S2: Micro-arc etching is performed on the surfaces of the anti-corrosion layer, the load-bearing layer, and the protective layer to form a rough interface; S3: The anti-corrosion layer, the load-bearing layer and the protective layer, which have been micro-arc etched, are stacked in order from top to bottom and placed in a rolling mill for three hot rolling passes to obtain aluminum alloy sheet. S4: The aluminum alloy sheet is subjected to solution treatment, quenching, and two-stage aging strengthening. S5: The aluminum alloy sheet treated in S4 is placed in an electrolyte and subjected to an electrolytic plasma oxidation reaction. After the edges are sealed, the corrosion-resistant aluminum alloy sheet for the battery is obtained.

4. The preparation process of corrosion-resistant aluminum alloy sheet for batteries according to claim 3, characterized in that, In S1, the thickness of the anti-corrosion layer is 8-12 mm, the thickness of the bearing layer is 14-16 mm, and the thickness of the protective layer is 8-12 mm.

5. The preparation process of corrosion-resistant aluminum alloy sheet for batteries according to claim 3, characterized in that, The melting temperature is 660-750℃, argon gas is introduced during the melting process of the anti-corrosion layer, and the bearing layer is melted under vacuum.

6. The preparation process of corrosion-resistant aluminum alloy sheet for batteries according to claim 3, characterized in that, The micro-arc etching forms a rough interface 45-55 μm deep on the surface of the alloy layer.

7. The preparation process of corrosion-resistant aluminum alloy sheet for batteries according to claim 3, characterized in that, The conditions for the three hot rolling passes are as follows: first pass: 55-65% compression at 400-450℃, second pass: 35-45% compression at 300-400℃, and last pass: 15-25% compression at 200-300℃.

8. The preparation process of corrosion-resistant aluminum alloy sheet for batteries according to claim 3, characterized in that, The solution treatment and quenching process specifically involves raising the aluminum alloy sheet to 500-520℃ at a rate of 10-15℃ / min, holding it at that temperature for 50-70 min, and then quenching it using high-pressure water mist. The dual-stage aging strengthening process includes primary aging and secondary aging. Primary aging refers to holding the aluminum alloy sheet at 115-125℃ for 7-9 h, and secondary aging refers to raising the temperature of the aluminum alloy sheet to 155-165℃ within 8-12 min.

9. The preparation process of corrosion-resistant aluminum alloy sheet for batteries according to claim 3, characterized in that, The electrolyte is composed of sodium silicate, ammonium molybdate and trisodium citrate in a mass ratio of 15-17:1:1-3.

10. The preparation process of corrosion-resistant aluminum alloy sheet for batteries according to claim 9, characterized in that, In the electrolytic plasma oxidation reaction, the anode is the S4-treated plate, the cathode is a stainless steel plate, the voltage is 250-300V, and the current density is 4.5-5.5A / dm³. 2 The reaction time is 8-10 min.

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