A lead storage battery positive plate and a method of making the same

Abstract

The application discloses a lead storage battery green plate and a preparation method thereof, and belongs to the field of lead storage batteries. The method comprises the following steps: preparing a polyvinyl alcohol solution with a mass fraction of 2.0%-3.0% as a coating solution, and spraying the coating solution on the surface of a plate before surface drying through an atomization mode; pre-drying the coated plate to make the polyvinyl alcohol form a film on the surface of the plate; and sequentially performing surface drying, curing and drying treatment on the plate after the film formation to obtain a green plate. Through the design of the water-based polyvinyl alcohol protective film formula and the three-stage process comprising atomization spraying, low-temperature micro-wind pre-drying and high-temperature surface drying, the plate surface is rapidly dried, the cracking caused by the rapid loss of moisture is avoided from the root, the production efficiency and the anti-cracking effect are considered, and no new quality and production defects are introduced. The prepared lead storage battery green plate is free of penetrating cracks, the plate surface is free of paste, the internal structure of the plate is optimized, and the large-current discharge performance of the battery is significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of lead-acid batteries, specifically relating to a lead-acid battery green plate and its preparation method. Background Technology

[0002] Lead-acid battery plates are manufactured in various ways, including ordinary casting, continuous casting, and mesh forming. During continuous production, to prevent adhesion between plates, surface drying treatment is necessary for the green plates, with temperatures ranging from 120℃ to 260℃ depending on the plate's condition. Green plates produced by continuous casting and mesh forming processes have a layer of coated paper applied to both sides for protection, making them less prone to cracking during the negative pressure surface drying process. However, green plates manufactured by ordinary casting lack this protective coating, leading to rapid moisture loss during surface drying. Uneven heating and localized overheating can also cause cracking defects in the plates.

[0003] Chinese patent application CN105470472A discloses a method for acid-leaching lead-acid battery plates. The process is as follows: Coated lead-acid battery plates are placed on a conveyor belt. Acid is applied in excess through an acid-leaching pipe onto the surface of an acid-pressing roller. When the plates are conveyed to the pressure roller, the roller rolls over them, causing the acid to adhere to the plate surface. The conveyor belt operates at a speed of 120-140 plates / minute, and the acid-leaching density of the positive lead-acid battery plates is 1.07-1.20 g / cm³. 3 The density of the acid leaching solution for the negative electrode plate of a lead-acid battery is 1.10-1.30 g / cm³. 3 The acid leaching method disclosed in this invention can enhance the surface strength of lead-acid battery plates, reduce dust shedding and plate scrap rate, thereby ensuring the safety and health of production personnel, and also enhancing battery performance.

[0004] The invention patent with publication number CN112768641A discloses a method for preparing a lead-acid battery electrode plate, and the lead-acid battery electrode plate, the process of which is as follows: preparing wet lead paste and coating it; subjecting the electrode plate obtained after coating to acid leaching or paper coating; subjecting the electrode plate after acid leaching or paper coating to surface drying; subjecting the surface-dried electrode plate to curing and drying to obtain the lead-acid battery electrode plate.

[0005] However, while the acid leaching process used to suppress cracking can delay surface water loss and reduce cracks to some extent, it also brings a series of new problems: 1. The amount of acid leaching is difficult to control evenly, and local acid accumulation is likely to occur, resulting in uneven internal structure of the electrode plate during subsequent curing and drying processes, which affects the consistency of the electrode plate. 2. Acid mist and residual acid can corrode equipment, deteriorate the production environment, and increase safety and environmental protection pressures; 3. After acid leaching, the surface of the electrode plate is acidic, which increases the difficulty of subsequent process control and has an adverse effect on the performance and stability of the battery. Summary of the Invention

[0006] To address the aforementioned technical problems in the prior art, this invention provides a lead-acid battery green plate and its preparation method, replacing the traditional acid leaching process, eliminating the scouring and corrosion of the plate by acid, improving the consistency of the plate's appearance and internal quality, simplifying the production process, improving the production environment, and ultimately obtaining a stable and reliable green plate, thereby enhancing the battery's high-current discharge performance.

[0007] The present invention provides a method for preparing a lead-acid battery raw electrode plate, comprising the following steps: (1) Prepare a polyvinyl alcohol solution with a mass fraction of 2.0%-3.0% as a coating liquid and spray it onto the surface of the electrode plate before it is dried by atomization. (2) The coated electrode plate is pre-dried to allow polyvinyl alcohol to form a film on the electrode plate surface; (3) After film formation, the electrode plate is subjected to surface drying, curing and drying treatment in sequence to obtain the green electrode plate.

[0008] This invention replaces the traditional acid-washing process with a three-stage process including atomized spraying, pre-drying, and surface drying, through the formulation design of an aqueous polyvinyl alcohol coating solution. This eliminates the scouring and corrosion of the electrode plate by the acid solution, fundamentally slows down the rapid loss of moisture from the surface of the green electrode plate during the surface drying process, ensures uniform heating of the electrode plate, avoids plaster cracking, improves the consistency of the electrode plate's appearance and internal quality, simplifies the production process, improves the production environment, and ultimately obtains a stable and reliable green electrode plate. The formulation design of the coating solution and the three-stage process synergistically enhance the high-current discharge performance of the electrode plate.

[0009] Furthermore, using an aqueous polyvinyl alcohol solution within the above-mentioned mass fraction range as the coating liquid can slow down the rapid loss of moisture from the electrode surface, ensure uniform heating, prevent the paste from cracking and sticking to the electrode, and allow it to decompose and be removed during the subsequent curing and drying process without affecting the electrode performance.

[0010] Preferably, in step (1), polyvinyl alcohol with a degree of hydrolysis of 87%-89% and a degree of polymerization of 500-1700 is dissolved in water and filtered to obtain a polyvinyl alcohol solution.

[0011] The solution prepared using the polyvinyl alcohol of the above specifications has excellent water solubility, and after filtration, it can ensure that the film on the subsequent electrode surface is uniform and free of impurities, while ensuring that the film layer can decompose on its own without residue.

[0012] More preferably, an 80-120 mesh filter is used for filtration.

[0013] Preferably, in step (1), the electrode is uniformly sprayed onto both sides of the electrode plate by atomization, wherein the coating amount on one side of the electrode plate is 2-12 g / m. 2 .

[0014] Using the above-mentioned spraying amount for atomized spraying ensures that a continuous and uniform liquid film is formed on both sides of the electrode plate, with no missed spraying (no protection) and no excessive spraying, effectively avoiding the film layer being too thick and affecting the surface drying efficiency.

[0015] Preferably, the pre-drying in step (2) is carried out by low temperature and light wind, with the temperature controlled at 35℃-45℃ and the wind speed at 0.2-0.8 m / s.

[0016] By using a low-temperature, micro-wind pre-drying method, the film layer is initially formed and the electrode surface is not sticky. A protective film is formed on the electrode surface before high-temperature surface drying, which effectively avoids the problem of electrode cracking caused by the high-temperature surface drying process and does not affect the electrode performance.

[0017] More preferably, the pre-drying time is 15-40 s.

[0018] Preferably, the surface drying temperature in step (3) is 80℃-105℃ and the surface drying time is 40-60 s.

[0019] The surface drying time is adjusted reasonably according to the thickness of the electrode plate. Higher values ​​are used for thicker plates, and vice versa for thinner plates. Generally, a thickness of 2 mm is used as a distinguishing factor. Using the parameters within the above range for surface drying can achieve rapid drying of the electrode plate surface under the protection of the water-based polyvinyl alcohol protective film, while avoiding cracking caused by rapid moisture loss, thus balancing production efficiency and crack prevention effect.

[0020] Preferably, the curing temperature in step (3) is 60℃-70℃ and the curing time is 30-35 h.

[0021] More preferably, the curing temperature in step (3) is 65°C and the curing time is 33 h.

[0022] Preferably, the drying temperature in step (3) is 60℃-80℃.

[0023] More preferably, the drying temperature in step (3) is 70°C.

[0024] On the other hand, the present invention also provides a lead-acid battery green plate prepared by the aforementioned method for preparing a lead-acid battery green plate.

[0025] On the other hand, the present invention also provides the application of the aforementioned lead-acid battery green plate in the preparation of lead-acid batteries.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention forms a film by spraying water-soluble polyvinyl alcohol onto the surface of the electrode plate, replacing the acid rinsing process. This eliminates the scouring and corrosion of the electrode plate by acid, and eliminates the need for dilute sulfuric acid, thus completely eliminating the problem of poor electrode plate quality caused by uneven acid rinsing. No acid mist is generated, which effectively improves the production environment and reduces the risk of acid mist corrosion to production equipment. The film layer has good volatility and can decompose and volatilize on its own during the subsequent curing and drying process of the electrode plate, avoiding the adverse effects of acid residue on the performance of the electrode plate and subsequent processes, thus taking into account both environmental protection and production safety. Furthermore, it slows down the rapid loss of moisture from the surface of the raw electrode plate during the surface drying process, making the electrode plate heat evenly and preventing the paste from cracking.

[0027] (2) Based on the design of the water-based polyvinyl alcohol protective film formulation, a three-stage process including atomized spraying, low-temperature micro-wind pre-drying and high-temperature surface drying is further combined to achieve rapid drying of the electrode surface, while avoiding cracking caused by rapid moisture loss. This balances production efficiency and crack prevention, and does not introduce new quality and production defects, further optimizing production convenience and electrode quality.

[0028] (3) The lead-acid batteries prepared by the above preparation method have no penetrating cracks and no paste on the surface of the plates, which optimizes the internal structure of the plates and significantly improves the high current discharge performance of the batteries. Attached Figure Description

[0029] Figure 1 The discharge capacity comparison curves are shown for the batteries of Example 1 and Comparative Example 1 of this invention.

[0030] Figure 2 The discharge capacity comparison curves are shown for the batteries of Example 2 and Comparative Example 2 of this invention.

[0031] Figure 3 The discharge capacity comparison curves are for the batteries of Example 3, Comparative Example 3, Comparative Example 4 and Comparative Example 5 of the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] To make the above-mentioned objectives, features and advantages of the present invention clearer and easier to understand, the following detailed description will be provided in conjunction with specific embodiments.

[0034] Example 1 7.5 kg of polyvinyl alcohol (PVA) with a degree of alcoholysis of 88% and a degree of polymerization of 900 was mixed and dissolved with 2992.5 kg of deionized water, and then filtered through an 80-120 mesh screen to remove impurities, resulting in a clear and transparent aqueous PVA solution coating liquid with a mass fraction of 2.5%. After applying paste to the cast 6-DZF-20 positive electrode plate (thickness 2.3±0.1 mm), the paste is then evenly sprayed onto both sides of the electrode plate using an atomizing spraying method, with the coating amount on one side controlled at 10 g / m². 2 Immediately after spraying, the film enters a low-temperature, low-wind pre-drying section, with the temperature controlled at 40±2℃, the wind speed at 0.5 m / s, and the pre-drying time at 25 s, so that the water-based PVA film can quickly form a preliminary film and the surface is non-sticky; then it enters a 100℃±2℃ section for 50 s to complete the surface drying process. After applying paste to the cast 6-DZF-20 negative electrode plate (thickness 1.6±0.1 mm), the paste is then evenly sprayed onto both sides of the electrode plate using an atomizing spraying method, with the coating amount on one side controlled at 10 g / m². 2 Immediately after spraying, the coating enters a low-temperature, low-wind pre-drying section, with the temperature controlled at 40±2℃, the wind speed at 0.5 m / s, and the pre-drying time at 25 s, so that the water-based PVA coating liquid can quickly form a preliminary film and the surface is non-sticky; then it enters an 85℃±2℃ section for 50 s to complete the surface drying process. After surface drying, the electrode plates are transferred to a curing chamber for curing. They are left to stand for 15 hours at a temperature of 65℃ and a relative humidity of 99%-100%. Then, the temperature and humidity are gradually reduced to 50℃ and 30% within 18 hours. Finally, they are dried at 70℃ for 12 hours to obtain the green electrode plates that meet the requirements.

[0035] Example 2 9 kg of PVA with a degree of alcoholysis of 87% and a degree of polymerization of 1700 was mixed and dissolved with 2991 kg of deionized water, and then filtered through an 80-120 mesh filter to remove impurities, resulting in a clear and transparent aqueous PVA solution coating liquid with a mass fraction of 3%. After applying paste to the cast 6-MF-24 positive electrode plate (thickness 2.9±0.1 mm), the paste is then evenly sprayed onto both sides of the electrode plate using an atomizing spraying method, with the coating amount on one side controlled at 8 g / m². 2 Immediately after spraying, the coating enters a low-temperature, low-wind pre-drying section, with the temperature controlled at 45±2℃, the wind speed at 0.2 m / s, and the pre-drying time at 15 s, so that the water-based PVA coating liquid can quickly form a preliminary film and the surface is non-sticky; then it enters a 105℃±2℃ section for 40 s to complete the surface drying process. After applying paste to the cast 6-MF-24 negative electrode plate (thickness 2.1±0.1 mm), the paste is then evenly sprayed onto both sides of the electrode plate using an atomizing spraying method, with the coating amount on one side controlled at 8 g / m². 2Immediately after spraying, the coating enters a low-temperature, low-wind pre-drying section, with the temperature controlled at 45±2℃, the wind speed at 0.2 m / s, and the pre-drying time at 15 s, so that the water-based PVA coating liquid can quickly form a preliminary film and the surface is non-sticky; then it enters a 92℃±2℃ section for 40 s to complete the surface drying process. After surface drying, the electrode plates are transferred to a curing chamber for curing. They are left to stand for 15 hours at a temperature of 60℃ and a relative humidity of 99%-100%. Then, the temperature and humidity are gradually reduced to 48℃ and a relative humidity of 35% within 16 hours. Finally, they are dried at 73℃ for 13 hours to obtain the green electrode plates that meet the requirements.

[0036] Example 3 6 kg of PVA with a degree of alcoholysis of 89% and a degree of polymerization of 500 was mixed and dissolved with 2994 kg of deionized water, and then filtered through an 80-120 mesh filter to remove impurities, resulting in a clear and transparent aqueous PVA solution coating liquid with a mass fraction of 2%. After applying paste to the cast 6-DZF-22 positive electrode plate (thickness 2.2±0.1 mm), the paste is then evenly sprayed onto both sides of the electrode plate using an atomizing spraying method, with the coating amount on one side controlled at 12 g / m². 2 Immediately after spraying, the coating enters a low-temperature, low-wind pre-drying section, with the temperature controlled at 35±2℃, wind speed at 0.8 m / s, and pre-drying time at 40 s, to allow the water-based PVA coating liquid to quickly form a preliminary film and prevent the surface from sticking; then it enters a 100℃±2℃ section for 60 s to complete the surface drying process. After applying paste to the cast 6-DZF-22 negative electrode plate (thickness 1.5±0.1 mm), the paste is then evenly sprayed onto both sides of the electrode plate using an atomizing spraying method, with the coating amount on one side controlled at 12 g / m². 2 Immediately after spraying, the coating enters a low-temperature, low-wind pre-drying section, with the temperature controlled at 35±2℃, wind speed at 0.8 m / s, and pre-drying time at 40 s, to allow the water-based PVA coating liquid to quickly form a preliminary film and prevent the surface from sticking; then it enters an 80℃±2℃ section for 60 s to complete the surface drying process. After surface drying, the electrode plates are transferred to a curing chamber for curing. They are left to stand for 14 hours at a temperature of 63℃ and a relative humidity of 99%-100%. Then, the temperature and humidity are gradually reduced to 55℃ and a relative humidity of 25% over 18 hours. Finally, they are dried at 75℃ for 12 hours to obtain the green electrode plates that meet the requirements.

[0037] Comparative Example 1 After applying paste to the cast 6-DZF-20 positive electrode plate, it is not subjected to acid leaching before undergoing a surface drying process. The surface drying process is completed in 50 seconds with a controlled temperature of 200±2℃ and an air velocity of 0.5 m / s. After applying paste to the cast 6-DZF-20 negative electrode plate, it is not subjected to acid leaching before undergoing a surface drying process. The surface drying process is completed in 50 seconds with a controlled temperature of 130±2℃ and an air velocity of 0.5 m / s. After surface drying, the electrode plates are transferred to a curing chamber for curing. They are left to stand for 15 hours at a temperature of 65℃ and a relative humidity of 99%-100%. Then, the temperature and humidity are gradually reduced to 50℃ and 30% within 18 hours. Finally, they are dried at 70℃ for 12 hours to obtain the green electrode plates that meet the requirements.

[0038] Comparative Example 2 After applying paste to the cast 6-MF-24 positive electrode plate, it is not subjected to acid leaching before undergoing a surface drying process. The surface drying process is completed in 40 seconds with a controlled temperature of 260±2℃ and an air velocity of 0.2 m / s. After applying paste to the cast 6-MF-24 negative electrode plate, it is not subjected to acid leaching before undergoing a surface drying process. The surface drying process is completed in 40 seconds with a controlled temperature of 170±2℃ and an air velocity of 0.2 m / s. After surface drying, the electrode plates are transferred to a curing chamber for curing. They are left to stand for 15 hours at a temperature of 60℃ and a relative humidity of 99%-100%. Then, the temperature and humidity are gradually reduced to 48℃ and 35% within 16 hours. Finally, they are dried at 73℃ for 13 hours to obtain the green electrode plates that meet the requirements.

[0039] Comparative Example 3 After the cast 6-DZF-22 positive electrode plate is coated with paste, it is treated with acid and then subjected to a surface drying process. The surface drying process is completed in 50 seconds with a controlled temperature of 180±2℃ and an air velocity of 0.5 m / s. After the cast 6-DZF-22 negative electrode plate is coated with paste, it is treated with acid and then subjected to a surface drying process. The surface drying process is completed in 50 seconds with a controlled temperature of 120±2℃ and an air velocity of 0.5 m / s. After surface drying, the electrode plates are transferred to a curing chamber for curing. They are left to stand for 14 hours at a temperature of 63℃ and a relative humidity of 99%-100%. Then, the temperature and humidity are gradually reduced to 55℃ and a relative humidity of 25% over 18 hours. Finally, they are dried at 75℃ for 12 hours to obtain the green electrode plates that meet the requirements.

[0040] Comparative Example 4 6 kg of PVA with a degree of alcoholysis of 89% and a degree of polymerization of 500 was mixed and dissolved with 2994 kg of deionized water, and then filtered through an 80-120 mesh filter to remove impurities, resulting in a clear and transparent aqueous PVA solution coating liquid with a mass fraction of 2%. After applying paste to the cast 6-DZF-22 positive and negative electrode plates, the above-mentioned protective coating liquid is evenly sprayed onto both sides of the plates using an atomizing spraying method, with the coating amount on one side controlled at 12 g / m². 2 ; After spraying, no low-temperature micro-wind pre-drying is performed; the surface drying process is directly initiated. The surface drying parameters are the same as in Example 3 (positive plate 100℃±2℃, 60 s; negative plate 80℃±2℃, 60 s). After surface drying, the electrode plates are transferred to a curing chamber for curing. They are left to stand for 14 hours at a temperature of 63℃ and a relative humidity of 99%-100%. Then, the temperature and humidity are gradually reduced to 55℃ and a relative humidity of 25% over 18 hours. Finally, they are dried at 75℃ for 12 hours to obtain the green electrode plates that meet the requirements.

[0041] Comparative Example 5 After casting the 6-DZF-22 positive and negative electrode plates and applying the paste, no PVA coating treatment is performed. Directly enter the low-temperature, light-wind pre-drying section, controlling the temperature at 35±2℃, the wind speed at 0.8 m / s, and the pre-drying time at 40 s; After pre-drying, the surface drying process begins, with the same parameters as in Example 3: surface drying temperature of the positive electrode plate is 100℃±2℃, and surface drying time is 60 s; surface drying temperature of the negative electrode plate is 80℃±2℃, and surface drying time is 60 s. After surface drying, the electrode plates are transferred to a curing chamber for curing. They are left to stand for 14 hours at a temperature of 63℃ and a relative humidity of 99%-100%. Then, the temperature and humidity are gradually reduced to 55℃ and a relative humidity of 25% over 18 hours. Finally, they are dried at 75℃ for 12 hours to obtain the green electrode plates that meet the requirements.

[0042] Green plates were prepared at different positions for the examples and comparative examples, and the cracking was checked. After the plates were assembled into batteries, the 3C high-current discharge performance was tested to verify the crack prevention effect and performance advantages of the present invention. Specifically, 10 plates were taken from each of the six positions (upper left, middle left, lower left, upper right, middle right, and lower right) of the curing chamber prepared by Examples 1-3 and Comparative Examples 1-5. The cracking of the lead paste on the plates was visually inspected under light, and the surface paste adhesion was also checked. The data are shown in Table 1.

[0043] Table 1 The raw plates prepared in Examples 1-3 and Comparative Examples 1-5 were assembled and charged to obtain 12 V batteries. The batteries were left to stand at 25°C for 24 h, and then discharged at 3 C until they reached 9.6 V. The discharge data are shown in Table 2.

[0044] Table 2 Combination Figures 1-3 The data in Table 2 shows that this solution can improve the cracking of lead paste on the plates without acid leaching. The battery prepared in this example discharged at 3C for an average of 10 min 45 s, while the comparative battery discharged for an average of 9 min 48 s, with the discharge time extended by 9.69%, which significantly improves the performance of the plates.

[0045] In summary, based on the experimental test data from Examples 1-3 and Comparative Examples 1-5, the core advantages of this invention are as follows: all advantages are supported by clear experimental data, fully demonstrating the advanced nature, practicality, and feasibility of the technical solution: 1. Significant crack prevention effect, completely solving industry pain points: Experimental data clearly shows that the positive and negative plates prepared in Examples 1-3 (the present invention's solution), when sampled and tested at six different locations in the curing chamber, showed no penetrating cracks, were all deemed qualified, and had no paste residue on the surface; while all plates in Comparative Examples 1-2 (no acid leaching, no protection) showed penetrating cracks and were deemed unqualified; although Comparative Example 4 (PVA coating only, no three-stage process) showed no penetrating cracks and was deemed qualified, the plate surface had paste residue problems, affecting subsequent production and plate quality. Meanwhile, the crack prevention effect of the present invention's solution is on par with Comparative Example 3 (acid leaching anti-crack process), with no penetrating cracks and both being deemed qualified. This indicates that the present invention can completely solve the industry pain point of surface cracking of ordinary cast electrode plates without the use of dilute sulfuric acid leaching. The crack prevention effect is better than the existing unprotected process, and is on par with the traditional acid leaching crack prevention process. Compared with Comparative Example 4, which only coated PVA, it can simultaneously ensure the crack prevention effect and the surface quality of the electrode plate, achieving acid-free, high-efficiency crack prevention and no paste residue on the surface.

[0046] 2. Improved high-current discharge performance of batteries, superior to existing technologies: 3C high-current discharge test data confirms that the present invention can significantly improve battery discharge performance: The average discharge time of batteries in Examples 1-3 is approximately 10 min 45 s; the average discharge time of Comparative Examples 1-2 (no protection, no acid coating) is approximately 9 min 30.5 s, and the present invention extends the discharge time by approximately 114.5 s, representing a performance improvement of 9.69%; the discharge time of Comparative Example 3 (acid coating for crack prevention) is 10 min 23 s, and the present invention extends the discharge time by 52 s, demonstrating superior discharge performance; the discharge time of Comparative Example 4 (PVA coating only, without the three-stage process) is 11 min 01 s, slightly shorter than Example 3 (11 min 12 s), proving that a single PVA coating cannot achieve the synergistic discharge performance advantages of the present invention's PVA and three-stage process. The above data fully demonstrate that the present invention can effectively optimize the internal structure of the electrode plates, significantly improve the high-current discharge performance of batteries, and is superior to traditional unprotected processes, acid coating processes, and single PVA coating solutions.

[0047] 3. Alternative to acid leaching process, overcoming various defects of existing technologies: This invention employs a water-based PVA protective film and a three-stage process in synergy, replacing the traditional acid leaching anti-cracking process. It fundamentally solves the inherent defects of the acid leaching process: It eliminates the need for dilute sulfuric acid, completely preventing the problem of inconsistent electrode quality caused by uneven acid leaching; it eliminates acid mist generation, effectively improving the production environment, reducing the risk of acid mist corrosion to production equipment, and reducing the pressure on enterprise safety and environmental management. Simultaneously, it avoids the adverse effects of residual acid on electrode performance and subsequent processes, balancing environmental protection and production safety. Compared to Comparative Example 4 (PVA coating only, without the three-stage process), this invention not only eliminates the need for acid leaching but also solves the problem of paste adhesion on the electrode surface, further optimizing production convenience and electrode quality.

[0048] 4. The process is simple and easy to control, enabling continuous industrial production: The core processes of this invention are: atomized PVA spraying, low-temperature micro-wind pre-drying, and high-temperature surface drying. The process is simple, and continuous industrial production can be achieved by adjusting the parameters of each step.

[0049] 5. No residue and no impact on the subsequent performance of the electrode plate and battery: The PVA film used in this invention has good volatility and can decompose and volatilize on its own during the subsequent curing and drying process of the electrode plate, leaving no residue. Unlike the acid leaching process, it will not produce acid residue, will not affect the conductivity and electrochemical performance of the electrode plate, and will not have an adverse impact on subsequent battery assembly, formation and other processes, thus ensuring the stability of the final battery performance.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a lead-acid battery green plate, characterized in that, Includes the following steps: (1) Prepare a polyvinyl alcohol solution with a mass fraction of 2.0%-3.0% as a coating liquid and spray it onto the surface of the electrode plate before it is dried by atomization. (2) The coated electrode plate is pre-dried to allow polyvinyl alcohol to form a film on the electrode plate surface; (3) After film formation, the electrode plate is subjected to surface drying, curing and drying treatment in sequence to obtain the green electrode plate.

2. The method for preparing a lead-acid battery green plate according to claim 1, characterized in that, In step (1), polyvinyl alcohol with a degree of hydrolysis of 87%-89% and a degree of polymerization of 500-1700 is selected, dissolved in water, and filtered to obtain a polyvinyl alcohol solution.

3. The method for preparing a lead-acid battery green plate according to claim 2, characterized in that, In step (1), an 80-120 mesh filter is used for filtration.

4. The method for preparing a lead-acid battery green plate according to claim 1, characterized in that, In step (1), the coating is uniformly sprayed onto both sides of the electrode plate by atomization, wherein the coating amount on one side of the electrode plate is 2-12 g / m. 2 .

5. The method for preparing a lead-acid battery green plate according to claim 1, characterized in that, The pre-drying in step (2) is carried out by low temperature and light wind, with the temperature controlled at 35℃-45℃ and the wind speed at 0.2-0.8 m / s.

6. The method for preparing a lead-acid battery green plate according to claim 5, characterized in that, The pre-drying time is 15-40 seconds.

7. The method for preparing a lead-acid battery green plate according to claim 1, characterized in that, In step (3), the surface drying temperature is 80℃-105℃ and the surface drying time is 40-60 s.

8. The method for preparing a lead-acid battery green plate according to claim 1, characterized in that, In step (3), the curing temperature is 60℃-70℃ and the curing time is 30-35 h; The drying temperature is 60℃-80℃.

9. A lead-acid battery green plate prepared by the method for preparing a lead-acid battery green plate according to any one of claims 1-8.

10. The application of the lead-acid battery green plate according to claim 9 in the preparation of lead-acid batteries.

Images