Corrosion-resistant aluminum alloy plate for battery and preparation process of corrosion-resistant aluminum alloy plate

Abstract

The invention discloses a corrosion-resistant aluminum alloy plate for a battery and a preparation process of the corrosion-resistant aluminum alloy plate, and belongs to the technical field of aluminum alloy processing. The corrosion-resistant aluminum alloy plate for the battery comprises a corrosion-resistant layer, a bearing layer and a protective layer which are sequentially stacked, the anti-corrosion layer comprises the following components in percentage by weight: 1 to 3 percent of Si, 0.2 to 1 percent of Mg, 0.05 to 0.2 percent of Fe, 0.01 to 0.2 percent of Cu and the balance of Al and inevitable impurities; the bearing layer comprises 0.08 wt%-0.25 wt% of Sc, 0.01 wt%-0.1 wt% of Zr, 0.2 wt%-1 wt% of Si, 0.1 wt%-0.5 wt% of Mn and the balance Al and inevitable impurities. And the protective layer comprises the following components in percentage by weight: 4 to 8 percent of Zn, 0.006 to 0.02 percent of Ga, 0.05 to 0.5 percent of Mg, 0.01 to 0.1 percent of Ti and the balance of Al and inevitable impurities. By adding Sc and Ga, an Al3Sc nanophase and a compact Ga2O3-Al2O3 composite oxide film are formed, the grain boundary corrosion potential is improved, local galvanic corrosion is inhibited, in addition, through a three-layer alloy structure, the functions of corrosion resistance, strong support and self protection are achieved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum alloy processing, and in particular relates to a corrosion-resistant aluminum alloy plate for batteries and a preparation process thereof. Background Art

[0002] With the rapid development of new energy vehicles and electronic devices, the performance requirements for battery materials are becoming increasingly higher. Aluminum alloy sheets for batteries need to have excellent corrosion resistance, mechanical properties, and processing properties to meet the requirements of battery housings, battery packs, and other components.

[0003] Traditional aluminum alloys have limitations in terms of corrosion resistance and mechanical properties. Aluminum alloys generally face a trade-off between high strength and high corrosion resistance: higher strength comes with lower corrosion resistance. High-strength aluminum alloys typically require the addition of a large number of alloying elements, which, while increasing strength, also increase the electrochemical activity of the material, thereby reducing corrosion resistance. Cold-rolled aluminum alloy sheets are susceptible to exfoliation corrosion. The fibrous structure formed during cold rolling is prone to intergranular corrosion. Corrosion develops along the grain boundaries in the rolling direction, and the resulting corrosion products expand in volume, causing blistering on the alloy surface. In severe cases, this can lead to lamellar lifting or flaking of the alloy surface. Furthermore, traditional aluminum alloy surface treatment processes, such as phosphating, have limitations. For example, the quality of the phosphate film significantly affects the corrosion resistance and paint adhesion of the aluminum alloy. However, excessively thick or low-quality phosphate films can reduce corrosion resistance. These limitations limit the application of aluminum alloys in harsh environments such as high humidity and high salt spray, necessitating the development of new corrosion-resistant aluminum alloy sheets. Summary of the Invention

[0004] Based on the deficiencies of the prior art, the purpose of the present invention is to provide a corrosion-resistant aluminum alloy plate for batteries and a preparation process thereof.

[0005] The first aspect of the present invention is to provide a corrosion-resistant aluminum alloy plate for batteries, comprising an anti-corrosion layer, a load-bearing layer, and a protective layer stacked in sequence; The anti-corrosion layer comprises Si 1-3 wt%, Mg 0.2-1 wt%, Fe 0.05-0.2 wt%, Cu 0.01-0.2 wt%, and the balance is Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%; The 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%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.15 wt%; 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%, and the balance is Al and inevitable impurities; the total content of the inevitable impurities is ≤0.15 wt%.

[0006] In some embodiments, the anti-corrosion layer includes Si 1.5-2 wt%, Mg 0.5-0. 8 wt%, Fe 0.1-0.15 wt%, Cu 0.01-0.1 wt%, and the balance is Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%; The bearing layer comprises Sc 0.12-0.18 wt%, Zr 0.04-0.08 wt%, Si 0.4-0.6 wt%, Mn 0.1-0.3 wt%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.15 wt%; The protective layer comprises Zn 6-7.5 wt%, Ga 0.008-0.015 wt%, Mg 0.1-0.3 wt%, Ti 0.01-0.03 wt%, and the balance is Al and inevitable impurities; the total content of the inevitable impurities is ≤0.15 wt%.

[0007] A second aspect of the present invention is to provide a process for preparing a corrosion-resistant aluminum alloy plate for batteries, comprising the following steps: S1: Melt the components according to their proportions and cast them into corrosion-resistant layer, bearing layer and protective layer; S2: Micro-arc etching is performed on the surface of the anti-corrosion layer, the bearing layer and the protective layer to form a rough interface; S3: stacking the anti-corrosion layer, the bearing layer, and the protective layer after micro-arc etching in order from top to bottom, placing the layers in a rolling mill for three hot rolling passes to obtain an aluminum alloy plate; S4: subjecting the aluminum alloy plate to solid solution, quenching, and double-stage aging treatment; S5: placing the aluminum alloy plate treated in S4 in an electrolyte to carry out an electrolytic plasma oxidation reaction, and sealing the edges to obtain a corrosion-resistant aluminum alloy plate for batteries.

[0008] In some embodiments, 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.

[0009] In some embodiments, the melting temperature is 660-750° C., argon gas is introduced during the melting process of the corrosion-resistant layer, and the bearing layer is melted in a vacuum.

[0010] In some embodiments, the micro-arc etching forms a rough interface with a depth of 45-55 μm on the surface of the alloy layer.

[0011] In some embodiments, the conditions of the three hot rolling passes are: first pass: 55-65% compression at 400-450°C, second pass: 35-45% compression at 300-400°C, and final pass: 15-25% compression at 200-300°C.

[0012] In the present invention, a three-pass hot rolling process is adopted. In the first pass, the interlayer etched microgrooves produce a local melting effect under high temperature and high pressure, which stimulates the diffusion of aluminum atoms across the interface and establishes a preliminary metallurgical bond; the second pass uses medium temperature and medium pressure to induce grain boundary migration, recrystallize under the synergy of Sc / Zr elements, and enhance the subsequent aging strengthening potential; the last pass uses low temperature and light pressing to eliminate interlayer thermal stress and strengthen the base surface structure.

[0013] In some embodiments, solution treatment and quenching specifically include raising the temperature of the aluminum alloy plate to 500-520°C at a rate of 10-15°C / min, holding the temperature for 50-70 minutes, and then quenching the plate using high-pressure water mist. Double-stage aging strengthening includes primary aging and secondary aging. The primary aging treatment involves holding the aluminum alloy plate at 115-125°C for 7-9 hours, and the secondary aging treatment involves raising the temperature of the aluminum alloy plate to 155-165°C within 8-12 minutes.

[0014] It should be noted that the present invention creatively adopts staged temperature control of nanophase precipitation. The first stage of aging is to form high-density Mg-Si-Cu aggregation at low temperature for a long time, thereby strengthening the supporting force of the plate. At the same time, low temperature drives the migration of Fe / Mn impurity atoms into the crystal, significantly reducing grain boundary segregation and reducing grain boundary corrosion current; in the second stage, short-term high temperature accelerates Sc / Zr diffusion, stimulates Al3(Sc,Zr) nanophase, avoids excessive diffusion of Zn / Ga, and when corrosion perforation occurs, Zn can react preferentially as an anode to prevent further spread of corrosion.

[0015] In some embodiments, the electrolyte is prepared by mixing sodium silicate, ammonium molybdate, and trisodium citrate in a mass ratio of 15-17:1:1-3.

[0016] It should be noted that the present invention adopts a new electrolyte formula, with ammonium molybdate ((NH4)2MoO4) as a corrosion inhibitor, and the aluminum alloy plate absorbs MoO4 through micropores. 2- Ions can be converted into MoO2F2 passivation film when encountering HF, blocking the corrosion of fluoride ions; sodium silicate forms a nano-SiO2 sealing layer, which can prevent the penetration of electrolyte.

[0017] In some embodiments, in the electrolytic plasma oxidation reaction, the anode is a plate treated with S4, the cathode is a stainless steel plate, the voltage is 250-300V, and the current density is 4.5-5.5A / dm 2 , the reaction time is 8-10 min.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention creatively adds Sc into the bearing layer of the aluminum alloy plate and Ga into the protective layer of the aluminum alloy plate. Sc can form Al3Sc nanophase with metal aluminum to block Cl - 、F - The three-layer structure adopted by the present invention has the functions of corrosion resistance, high pressure resistance, and self-repair. The anti-corrosion layer can form an amorphous SiO2 passivation film, which plays an anti-corrosion role. The supporting 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.

[0019] This invention uses etching and hot rolling technology to achieve atomic-level metallurgical bonding between layers, avoiding the problem of interfacial delamination of the composite sheet. A dual-stage aging hardening technique simultaneously improves matrix strength and grain boundary corrosion resistance, overcoming the conflict between high strength and high corrosion. Electrolytic plasma oxidation technology creates a self-healing microporous membrane layer on the surface, effectively blocking hydrogen fluoride corrosion in the electrolyte. These three technologies work together to form a stable system of strong matrix and strong protection, which can extend the service life of the battery under extreme operating conditions. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to specific embodiments.

[0021] Example 1 A corrosion-resistant aluminum alloy plate for batteries, comprising an anti-corrosion layer, a load-bearing layer, and a protective layer stacked in sequence; The anti-corrosion layer comprises Si 1.8 wt%, Mg 0.7 wt%, Fe 0.12 wt%, Cu 0.05 wt%, and the balance is Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%; The bearing layer comprises Sc 0.15 wt%, Zr 0.06 wt%, Si 0.5 wt%, Mn 0.2 wt%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.15 wt%; The protective layer includes 6.5 wt% of Zn, 0.012 wt% of Ga, 0.2 wt% of Mg, and 0.02 wt% of Ti, with the remainder being Al and inevitable impurities; the total content of the inevitable impurities is ≤0.15 wt%.

[0022] The above-mentioned corrosion-resistant aluminum alloy plate for battery is prepared by the following steps: S1: Melting is performed according to the component ratio. The corrosion-resistant layer is melted and cast into an alloy ingot with a thickness of 10 mm at 720°C under argon protection. The bearing layer is cast into an alloy ingot with a thickness of 15 mm at 740°C under vacuum. The protective layer is cast into an alloy ingot with a thickness of 10 mm at 660°C. S2: Micro-arc etching is performed on the surface of the anti-corrosion layer, the bearing layer and the protective layer to form a 50 μm deep rough interface; S3: The anti-corrosion layer, the bearing layer, and the protective layer after micro-arc etching are stacked in order from top to bottom, and then placed in a rolling mill for three passes of hot rolling to obtain an aluminum alloy plate; wherein, the first pass: 60% compression at 450°C, the second pass: 40% compression at 350°C, and the final pass: 20% compression at 250°C; S4: The hot-rolled aluminum alloy plate is solution-hardened and quenched, and the temperature is raised to 510°C at a rate of 15°C / min and kept at this temperature for 60 minutes. Then, a two-stage aging treatment is performed. The first stage aging treatment is to keep the plate at 120°C for 8 hours, and the second stage aging treatment is to raise the plate temperature to 160°C within 10 minutes. S5: The aluminum alloy plate treated with S4 was placed in an electrolyte composed of sodium silicate, ammonium molybdate and trisodium citrate in a mass ratio of 16:1:2 for electrolytic plasma oxidation reaction. The anode was the plate treated with S4, the cathode was the stainless steel plate, the voltage was 300 V, and the current density was 5 A / dm 2 , the reaction time is 10 min, and finally the edge is sealed to obtain the corrosion-resistant aluminum alloy plate for battery.

[0023] Example 2 A corrosion-resistant aluminum alloy plate for batteries, comprising an anti-corrosion layer, a load-bearing layer, and a protective layer stacked in sequence; The anti-corrosion layer comprises Si 2 wt%, Mg 0.8 wt%, Fe 0.15 wt%, Cu 0.1 wt%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.2 wt%; The bearing layer includes Sc 0.18 wt%, Zr 0.08 wt%, Si 0.6 wt%, Mn 0.3 wt%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.15 wt%; The protective layer includes Zn 7.5 wt%, Ga 0.015 wt%, Mg 0.3 wt%, Ti 0.03 wt%, and the balance is Al and inevitable impurities; the total content of the inevitable impurities is ≤0.15 wt%.

[0024] The above-mentioned corrosion-resistant aluminum alloy plate for battery is prepared by the following steps: S1: Melting is performed according to the component ratio. The corrosion-resistant layer is melted and cast into an alloy ingot with a thickness of 12 mm at 720°C under argon protection. The bearing layer is cast into an alloy ingot with a thickness of 116 mm at 740°C in vacuum. The protective layer is cast into an alloy ingot with a thickness of 12 mm at 660°C. S2: Micro-arc etching is performed on the surface of the anti-corrosion layer, the bearing layer and the protective layer to form a 55 μm deep rough interface; S3: The anti-corrosion layer, the bearing layer, and the protective layer after micro-arc etching are stacked in order from top to bottom, and then placed in a rolling mill for three hot rolling passes to obtain an aluminum alloy plate; wherein, the first pass: 65% compression at 450℃, the second pass: 45% compression at 400℃, and the final pass: 25% compression at 300℃; S4: The hot-rolled aluminum alloy plate is solution-hardened and quenched, and the temperature is raised to 520°C at a rate of 15°C / min and kept at this temperature for 70 minutes. Then, a two-stage aging treatment is performed. The first stage aging treatment is to keep the plate at 125°C for 9 hours, and the second stage aging treatment is to raise the plate temperature to 165°C within 12 minutes. S5: The aluminum alloy plate treated with S4 was placed in an electrolyte composed of sodium silicate, ammonium molybdate and trisodium citrate in a mass ratio of 17:1:3, and an electrolytic plasma oxidation reaction was carried out. The anode was the plate treated with S4, the cathode was the stainless steel plate, the voltage was 300 V, and the current density was 5.5 A / dm 2 , the reaction time is 10 min, and finally the edge is sealed to obtain the corrosion-resistant aluminum alloy plate for battery.

[0025] Example 3 A corrosion-resistant aluminum alloy plate for batteries, comprising an anti-corrosion layer, a load-bearing layer, and a protective layer stacked in sequence; The anti-corrosion layer comprises Si 1.5 wt%, Mg 0.5 wt%, Fe 0.1 wt%, Cu 0.01 wt%, and the balance is Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.2 wt%; The bearing layer includes Sc 0.12 wt%, Zr 0.04 wt%, Si 0.4 wt%, Mn 0.1 wt%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.15 wt%; The protective layer includes Zn 6 wt%, Ga 0.008 wt%, Mg 0.1 wt%, Ti 0.01 wt%, and the balance is Al and inevitable impurities; the total content of the inevitable impurities is ≤0.15wt%.

[0026] The above-mentioned corrosion-resistant aluminum alloy plate for battery is prepared by the following steps: S1: Melting is performed according to the component ratio. The corrosion-resistant layer is melted and cast into an alloy ingot with a thickness of 8 mm at 720°C under argon protection. The bearing layer is cast into an alloy ingot with a thickness of 14 mm at 740°C in vacuum. The protective layer is cast into an alloy ingot with a thickness of 8 mm at 660°C. S2: Micro-arc etching is performed on the surface of the anti-corrosion layer, the bearing layer and the protective layer to form a 45 μm deep rough interface; S3: The anti-corrosion layer, the bearing layer, and the protective layer after micro-arc etching are stacked in order from top to bottom, and then placed in a rolling mill for three hot rolling passes to obtain an aluminum alloy plate; wherein, the first pass: 55% compression at 400°C, the second pass: 35% compression at 300°C, and the final pass: 15% compression at 200°C; S4: The hot-rolled aluminum alloy plate is solution-hardened and quenched, and the temperature is raised to 500°C at a rate of 10°C / min and kept at this temperature for 50 minutes. Then, a two-stage aging treatment is performed. The first stage aging treatment is to keep the plate at 115°C for 7 hours, and the second stage aging treatment is to raise the plate temperature to 155°C within 8 minutes. S5: The aluminum alloy plate treated with S4 was placed in an electrolyte composed of sodium silicate, ammonium molybdate and trisodium citrate in a mass ratio of 15:1:1, and an electrolytic plasma oxidation reaction was carried out. The anode was the plate treated with S4, the cathode was the stainless steel plate, the voltage was 250V, and the current density was 4.5A / dm 2 The reaction time is 8 min, and finally the edge is sealed to obtain the corrosion-resistant aluminum alloy plate for battery.

[0027] Example 4 It is basically the same as Example 1, with the only difference being: The components of the anti-corrosion layer, the load-bearing layer, and the protective layer of the corrosion-resistant aluminum alloy plate for batteries provided in this embodiment are as follows: The anti-corrosion layer comprises Si 3 wt%, Mg 1 wt%, Fe 0.2 wt%, Cu 0.2 wt%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.2wt%; The bearing layer includes Sc 0.25 wt%, Zr 0.1 wt%, Si 1 wt%, Mn 0.5 wt%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.15 wt%; The protective layer includes 8 wt% of Zn, 0.02 wt% of Ga, 0.5 wt% of Mg, and 0.1 wt% of Ti, with the remainder being Al and inevitable impurities; the total content of the inevitable impurities is ≤0.15 wt%.

[0028] Example 5 It is basically the same as Example 1, with the only difference being: The components of the anti-corrosion layer, the load-bearing layer, and the protective layer of the corrosion-resistant aluminum alloy plate for batteries provided in this embodiment are as follows: The anti-corrosion layer comprises Si 1 wt%, Mg 0.2 wt%, Fe 0.05 wt%, Cu 0.01 wt%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.2wt%; The bearing layer includes Sc 0.08 wt%, Zr 0.01 wt%, Si 0.2 wt%, Mn 0.1 wt%, and the balance is Al and inevitable impurities; the total content of inevitable impurities is ≤0.15 wt%; The protective layer includes 4 wt% of Zn, 0.006 wt% of Ga, 0.05 wt% of Mg, and 0.01 wt% of Ti, with the remainder being Al and inevitable impurities; the total content of the inevitable impurities is ≤0.15 wt%.

[0029] Comparative Example 1 The method is basically the same as Example 1, except that Sc is replaced by the same amount of Y.

[0030] Comparative Example 2 The process is basically the same as that of Example 1, except that Ga is replaced with the same amount of In.

[0031] Comparative Example 3 It is basically the same as Example 1, except that a single-layer structure is adopted, that is, the chemical composition of the three-layer alloy is smelted into a single-layer homogeneous alloy with a thickness of 35 mm, and the element components are calculated as the sum of the three layers. The composition of the aluminum alloy plate is as follows: Si 2.3wt%, Mg 0.9 wt%, Fe 0.12 wt%, Cu 0.05 wt%, Sc 0.15 wt%, Zr 0.06 wt%, Mn 0.2 wt%, Zn6.5 wt%, Ga 0.012 wt%, Ti 0.02 wt%, and the balance is Al and unavoidable impurities; the total content of unavoidable impurities is ≤0.15wt%.

[0032] Comparative Example 4 The method is basically the same as Example 1, with the only difference being that the three-pass hot rolling is replaced by a single hot rolling, that is, the hot rolling condition is 81% compression at 400°C.

[0033] Comparative Example 5 The method is basically the same as Example 1, with the only difference being that the double-stage aging strengthening is replaced by single-stage aging strengthening, that is, the aluminum alloy plate is kept at 160° C. for 10 h.

[0034] Comparative Example 6 The process is basically the same as that of Example 1, except that the electrolytic plasma oxidation is replaced by ordinary anodic oxidation.

[0035] In order to demonstrate that the corrosion-resistant aluminum alloy plate for batteries provided by the present invention has excellent mechanical properties and corrosion resistance, performance tests were performed on Examples 1-5 and Comparative Examples 1-6 below. The test results are shown in Table 1.

[0036] Mechanical properties test: GB / T 16865 rectangular standard specimen with fixed gauge length P001 specimen is used for testing. The sampling direction is parallel to the rolling direction. The test is carried out according to the room temperature tensile method of GB / T 228.1.

[0037] Intergranular corrosion resistance test: ASTM G67-2018, 500 hours test.

[0038] Exfoliation corrosion resistance test: refer to GB / T 22639-2022.

[0039] Table 1 As can be seen from Table 1, the corrosion-resistant aluminum alloy plate for batteries provided by 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 the comparative examples are relatively weak. In comparative examples 1 and 2, Sc is replaced by Y and Ga is replaced by In, respectively, resulting in a decrease in the mechanical properties and corrosion resistance of the plate, indicating that Sc and Ga are irreplaceable in the present invention. Comparative examples 3-6 respectively adopt a single-layer alloy structure, a single-pass hot rolling, a single-stage aging strengthening and ordinary anodizing, resulting in a significant decrease in the various properties of the aluminum alloy plate.

[0040] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

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

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

3. A process for preparing the corrosion-resistant aluminum alloy plate for batteries according to claim 1 or 2, characterized in that: The following steps are involved: S1: Melt the components according to their proportions and cast them into corrosion-resistant layer, bearing layer and protective layer; S2: Micro-arc etching is performed on the surface of the anti-corrosion layer, the bearing layer and the protective layer to form a rough interface; S3: stacking the anti-corrosion layer, the bearing layer, and the protective layer after micro-arc etching in order from top to bottom, placing the layers in a rolling mill for three hot rolling passes to obtain an aluminum alloy plate; S4: subjecting the aluminum alloy plate to solid solution, quenching, and double-stage aging treatment; S5: placing the aluminum alloy plate treated in S4 in an electrolyte to perform an electrolytic plasma oxidation reaction, and sealing the edges to obtain the corrosion-resistant aluminum alloy plate for the battery.

4. The process for preparing the corrosion-resistant aluminum alloy plate for batteries according to claim 3, characterized in that: 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 process for preparing the corrosion-resistant aluminum alloy plate for batteries according to claim 3, characterized in that: The smelting temperature is 660-750° C., argon gas is introduced during the smelting process of the anti-corrosion layer, and the bearing layer is smelted in a vacuum.

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

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

8. The process for preparing the corrosion-resistant aluminum alloy plate for batteries according to claim 3, characterized in that: The solution treatment and quenching specifically involves raising the temperature of the aluminum alloy plate to 500-520°C at a rate of 10-15°C / min, keeping the temperature for 50-70 minutes, and then quenching with high-pressure water mist. The two-stage aging strengthening includes primary aging and secondary aging. The primary aging refers to keeping the aluminum alloy plate at 115-125°C for 7-9 hours, and the secondary aging refers to raising the temperature of the aluminum alloy plate to 155-165°C within 8-12 minutes.

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

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

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