A pre-treatment method for internalization into a green plate

Abstract

The application provides a preprocessing method for internalization of a green plate, the green plate having an upper surface, comprising: treating a solidified dry green plate into a wet green plate by water or an aqueous solution, free water or free aqueous solution being retained on the upper surface of the treated wet green plate; removing the free water or free aqueous solution retained on the upper surface of the wet green plate; then surface drying the wet green plate; and wrapping the surface-dried wet green plate. The application also protects a manufacturing method of a lead-acid battery. The preprocessing method for internalization of a green plate and the manufacturing method of the application ensure the service life of the lead-acid battery.

Description

Technical Field

[0001] This invention relates to the field of lead-acid battery manufacturing, and in particular to a pretreatment method for green plates used in internal formation. Background Technology

[0002] The applicant previously applied for a method of treating cured dry green plates with water or an aqueous solution to create wet green plates. To reduce the short-circuit risk of lead-acid batteries after the wet green plates are laminated, the wet green plates need to be dried or air-dried before lamination. Due to the curvature of the upper surface of the green plate, the amount of free water or free aqueous solution retained on different locations on the upper surface of the green plate varies. Even after drying or air-drying under the same conditions, the water content of different locations on the upper surface of the same wet green plate is inconsistent in the direction perpendicular to the upper surface of the plate. In addition, the amount of free water or free aqueous solution retained on different wet green plates after processing also varies. Even after drying or air-drying different wet green plates under the same conditions, the water content of different wet green plates will be inconsistent. After lamination and placement in the cell, this will lead to inconsistent water content between individual cells of the lead-acid battery, which in turn will reduce the life of the lead-acid battery. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a pretreatment method for a green electrode plate for internalization. The green electrode plate has an upper surface. The cured dry green electrode plate is treated with water or an aqueous solution to become a wet green electrode plate. Free water or an aqueous solution is retained on the upper surface of the treated wet green electrode plate. The free water or aqueous solution retained on the upper surface of the wet green electrode plate is removed. The wet green electrode plate is then surface-dried. The surface-dried wet green electrode plate is then coated.

[0004] Furthermore, free water or free aqueous solution leaves the upper surface of the wetted electrode by being pushed away by an external force.

[0005] Furthermore, the direction of the external thrust is along the extension direction of the upper surface of the wetted electrode plate.

[0006] Furthermore, the aqueous solution is an aqueous solution of sulfuric acid or an aqueous solution of sulfate.

[0007] Furthermore, the cured dry green electrode plate is a positive dry green electrode plate. The pretreatment method pretreats at least two positive dry green electrode plates, and the pretreated at least two positive wet green electrode plates are surface dried under the same surface drying conditions.

[0008] Furthermore, the cured dry electrode plates are treated by soaking or pouring.

[0009] Furthermore, the surface is dried by baking or air drying.

[0010] Furthermore, the drying temperature is 100℃-200℃, and the drying time is 10-20 seconds.

[0011] Furthermore, the moisture content of the wetted electrode plate after surface drying is 2%-7.5%.

[0012] The present invention also protects a method for manufacturing a lead-acid battery, wherein a wet green plate obtained by the pretreatment method of the green plate of the present invention is placed into a battery case, and acid is added and the battery is formed.

[0013] The pretreatment method for the internal formation of the green plate of the present invention ensures the lifespan of the lead-acid battery. Detailed Implementation

[0014] The present invention will be further described below with reference to specific embodiments.

[0015] The present invention discloses a pretreatment method for a green electrode plate for internalization. The green electrode plate has an upper surface. The cured dry green electrode plate is treated with water or an aqueous solution to become a wet green electrode plate. Free water or an aqueous solution is retained on the upper surface of the treated wet green electrode plate. The free water or aqueous solution retained on the upper surface of the wet green electrode plate is removed. The wet green electrode plate is then surface-dried. The surface-dried wet green electrode plate is then coated.

[0016] The cured dry electrode plate is treated with water or an aqueous solution, preferably by soaking or pouring. The aqueous solution can be a sulfuric acid solution, preferably with a density between 1.00 g / mL and 1.20 g / mL (25°C), more preferably between 1.04 g / mL and 1.08 g / mL (25°C). The aqueous solution of the present invention can also be a sulfate aqueous solution, such as a stannous sulfate aqueous solution. Treating the cured dry electrode plate with water or an aqueous solution ensures that the water reaches the bottom of the active material, that is, the part near the grid. During formation, an electrochemical reaction first occurs to generate the framework structure, ensuring the supporting effect of the bottom of the active material. A relatively large amount of α-PbO2 can be generated at the bottom of the active material of the positive electrode plate, and a relatively large amount of framework lead can be generated at the bottom of the active material of the negative electrode plate, ensuring the bonding force between the active material and the grid.

[0017] To achieve the desired effect of transforming the cured dry green electrode plate into a wet green electrode plate, ensuring that water effectively penetrates the pores of the corrosion layer, the positive electrode plate is treated as follows: The cured dry green electrode plate is immersed or poured with water at a temperature of 5℃~50℃ for 5~80 minutes, preferably until no more bubbles emerge from the electrode plate surface. This allows the water to completely fill the pores of the active material in the green electrode plate. After immersion or pouring, a wet green electrode plate is obtained, at which point free water remains on the surface of the wet electrode plate.

[0018] Alternatively, the present invention involves soaking or rinsing the cured dry green electrode plate with dilute sulfuric acid, preferably with a density less than 1.20 g / mL and between 1.04 g / mL and 1.08 g / mL, at a temperature of 5°C to 50°C for 5 to 80 minutes, preferably until no more bubbles emerge from the electrode plate surface. This allows the aqueous solution to completely fill the pores of the active material in the green electrode plate. After soaking or rinsing, a wet green electrode plate is obtained, at which point a free aqueous solution, i.e., dilute sulfuric acid, remains on the surface of the wet green electrode plate.

[0019] Alternatively, in a similar manner, the present invention soaks or pours the cured dry green electrode plate with sulfate, such as stannous sulfate; or in a similar manner, the present invention soaks or pours the cured dry green electrode plate with a mixed aqueous solution, such as a mixed aqueous solution of bismuth sulfate and low-density sulfuric acid, or a mixed aqueous solution of antimony sulfate and low-density sulfuric acid, etc., preferably until no more bubbles emerge from the electrode plate surface, so that the mixed aqueous solution can completely fill the pores of the active material in the green electrode plate. The density of the dilute sulfuric acid in the present invention refers to the density at room temperature (25°C). At this time, the surface of the wet green electrode plate retains free aqueous solution, i.e., stannous sulfate, bismuth sulfate, or a mixed aqueous solution.

[0020] The aqueous solution used in this invention to process the cured dry green electrode plate into a wet green electrode plate can be a neutral, weakly acidic, or weakly alkaline aqueous solution, all of which can achieve the technical effect of this invention.

[0021] The negative electrode plate can also be selectively processed using a similar method to the positive electrode plate, depending on the need.

[0022] This invention provides a pretreatment method for a green electrode plate used in internalization. This method removes free water or free aqueous solution retained on the upper surface of the wet green electrode plate. The free water or free aqueous solution can be pushed away from the upper surface of the wet green electrode plate by an external pushing force. This ensures that the amount of free water or free aqueous solution retained at different positions on the upper surface of the same wet green electrode plate is consistent in the direction perpendicular to the upper surface. The direction of the external pushing force is preferably along the extension direction of the upper surface of the wet green electrode plate. This external pushing force removes as much free water or free aqueous solution as possible from the upper surface of the wet green electrode plate, making it easier to ensure that the amount of free water or free aqueous solution retained on the same wet green electrode plate is consistent. The amount of free water or free water solution retained at different positions on the surface in the direction perpendicular to the electrode surface is consistent. When the surface is dried, the surface drying conditions at different positions on the upper surface of the same wet electrode are the same, such as the same temperature and the same time. After surface drying, the water content at different positions on the upper surface of the same wet electrode in the direction perpendicular to the upper surface of the electrode is consistent. This ensures the consistency of the α-PbO2 content generated at the bottom of the positive electrode active material during formation, ensures the consistency of the interface, and avoids the risk of inconsistent discharge between the upper and lower electrodes, thereby ensuring the life of the lead-acid battery. The external thrust of this invention refers to the free water or free water solution being pushed by an external force, rather than by its own gravity. This ensures the consistency of the amount of free water or free water solution retained at different positions on the upper surface of the same wetted electrode plate in the direction perpendicular to the electrode plate surface. It also improves the efficiency of ensuring the consistency of the amount of free water or free water solution retained at different positions on the upper surface of the same wetted electrode plate in the direction perpendicular to the electrode plate surface. It removes as much free water or free water solution retained on the upper surface of the wetted electrode plate as possible. That is, the external thrust is applied along the extension direction of the upper surface of the wetted electrode plate to remove the free water or free water retained on the upper surface of the wetted electrode plate. This reduces the surface drying time and improves the pretreatment efficiency of the internalization forming electrode plate.

[0023] To further illustrate, the water content at different locations on the upper surface of the same wet-grown electrode plate is consistent in the direction perpendicular to the upper surface of the electrode plate. For example, if there are two locations on the upper surface of the same wet-grown electrode plate, point a and point b, and a perpendicular line A passes through point a perpendicular to the upper surface of the electrode plate with direction A, and a perpendicular line B passes through point b perpendicular to the upper surface of the electrode plate with direction B, then the water content at points a and b on the upper surface of the same wet-grown electrode plate is consistent in both the direction A and the direction B perpendicular to the upper surface of the electrode plate.

[0024] The present invention relates to a wetted electrode plate obtained by processing the cured dry green electrode plate. The moisture content of the wetted electrode plate is higher than that of the cured dry green electrode plate. The moisture content of the wetted electrode plate is preferably greater than 6%, and typically not exceeding 8.5%. After surface drying, the moisture content of the wetted electrode plate is preferably between 2% and 7.5%. Surface drying ensures that the surface of the wetted electrode plate is not dripping wet before coating, i.e., the surface of the wetted electrode plate is moist but not wet, which reduces the risk of short circuits after coating into the substrate. The surface drying method for the wetted electrode plate can be air drying, but oven drying is preferred. The oven drying temperature is preferably 100℃-200℃, and the drying time is preferably 10-20 seconds, thus obtaining a wetted electrode plate that meets the requirements. Furthermore, the adhesion of the lead paste to the wetted electrode plate is higher than that of the green electrode plate before curing after coating.

[0025] In this invention, the cured dry green electrode plate is preferably a positive dry green electrode plate. The pretreatment method involves pretreating at least two positive dry green electrode plates into two positive wet green electrode plates. The pretreatment method is the same as described above, that is, soaking or rinsing until no more bubbles emerge from the surface of the two positive green electrode plates. This allows the water or aqueous solution to completely fill the pores of the active material in the two positive green electrode plates. At this point, free water or free aqueous solution remains on the surface of the two positive green electrode plates. The two positive dry green electrode plates are for the same type of lead-acid battery. The lead paste used for the two positive dry electrode plates is usually the same type of lead paste and the same weight of paste is applied. In short, the paste application should meet the coating standard requirements. Ideally, the external pushing force should be directed along the surface extension of the wetted electrode plate. After removing all free water or free water solution remaining on the surfaces of the two positive wetted electrode plates through this external pushing force, the water content between the two positive wetted electrode plates will be consistent. Surface drying of the two positive wetted electrode plates under the same conditions ensures consistent water content after surface drying, reducing the risk of inconsistent water content between lead-acid battery cells after the two positive wetted electrode plates are wrapped into different cells, thus ensuring the battery's lifespan. Similarly, this method also applies to processing two negative dry electrode plates into two negative wetted electrode plates, achieving the same technical effect. Under the same surface drying conditions, the same drying temperature and the same drying time are required. For example, two positive wetted electrode plates can be dried at the same temperature of 150℃ for the same time of 15 seconds.

[0026] This invention processes the cured dry green plates into wet green plates, and then uses external force to remove as much free water or free aqueous solution as possible from the surface of the wet green plates. This ensures good consistency in moisture content among different wet green plates after the removal of all free water or free aqueous solution. The wet green plates are then surface-dried. Because the moisture content of different wet green plates is almost identical after removing the free water or free aqueous solution, surface drying under the same conditions ensures good consistency in moisture content among the different wet green plates after surface drying. This reduces the risk of inconsistent moisture content between lead-acid battery cells after different wet green plates are packaged into different cells, thus ensuring the lifespan of the lead-acid battery. Good consistency in moisture content among different wet green plates refers to good consistency between different positive wet green plates or different negative wet green plates. In this invention, different wet green plates refer to different wet green plates that can be used in the same type of lead-acid battery. Furthermore, by using external force to push away free water or free water solution from the upper surface of the wetted electrode plate, the amount of free water or free water solution retained at different positions on the upper surface of the same wetted electrode plate in the direction perpendicular to the upper surface of the electrode plate is consistent. Different positions on the upper surface of the same wetted electrode plate are dried under the same surface drying conditions. After surface drying, the water content at different positions on the upper surface of the same wetted electrode plate in the direction perpendicular to the upper surface of the electrode plate is consistent. That is, the water content at different positions on the upper surface of the same wetted electrode plate in the direction perpendicular to the upper surface of the electrode plate is almost the same. After the wetted electrode plate is wrapped into the tank, the risk of inconsistent water content between individual cells of lead-acid battery is also reduced, thus ensuring the life of lead-acid battery.

[0027] This invention also protects a method for manufacturing a lead-acid battery, in which a wet green plate obtained by the pretreatment method of the green plate of this invention is placed into a battery cell, acid is added, and formation is performed. The density of the sulfuric acid aqueous solution used for formation is preferably between 1.3 g / mL and 1.5 g / mL. In addition, before processing the cured dry green plate into a wet green plate, the method may include processes such as paste preparation, plate coating, and curing.

[0028] The upper surface mentioned in this invention is preferably the surface with the largest surface area of ​​the green electrode plate.

[0029] The lead-acid battery prepared by this invention has good consistency between individual cells, which helps to ensure the lifespan of the lead-acid battery.

[0030] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A pretreatment method for a green electrode plate for internalization, wherein the green electrode plate has an upper surface, characterized in that, include: The cured dry electrode plate is treated with water or an aqueous solution to become a wet electrode plate. After treatment, free water or an aqueous solution remains on the upper surface of the wet electrode plate. The free water or aqueous solution remaining on the upper surface of the wet electrode plate is removed. The wet electrode plate is then surface-dried. The surface-dried wet electrode plate is then coated.

2. The pretreatment method for an internalized green electrode plate as described in claim 1, characterized in that, The free water or free aqueous solution leaves the upper surface of the wetted electrode plate by being pushed away by an external force.

3. The pretreatment method for internalization of a green electrode plate as described in claim 2, characterized in that, The direction of the external thrust is along the extension direction of the upper surface of the wetted electrode plate.

4. The pretreatment method for an internalized green electrode plate as described in claim 1, characterized in that, The aqueous solution is a sulfuric acid solution or a sulfate solution.

5. The pretreatment method for an internalized green electrode plate as described in claim 3, characterized in that, The cured dry green electrode plate is a positive dry green electrode plate. The pretreatment method pretreats at least two of the positive dry green electrode plates. After pretreatment, at least two positive wet green electrode plates are surface dried under the same surface drying conditions.

6. The pretreatment method for internalization of a green electrode plate as described in claim 1, characterized in that, The cured dry electrode plate is treated by soaking or pouring.

7. The pretreatment method for internalization of a green electrode plate as claimed in claim 1, characterized in that, The surface drying method is baking.

8. The pretreatment method for internalization of a green electrode plate as described in claim 7, characterized in that, The drying temperature is 100℃-200℃, and the drying time is 10-20 seconds.

9. The pretreatment method for internalization of a green electrode plate as claimed in claim 1, characterized in that, The moisture content of the wetted electrode plates after surface drying is 2%-7.5%.

10. A method for manufacturing a lead-acid battery, characterized in that, The wet green plate obtained by any one of the pretreatment methods for the green plate of claims 1-9 is placed into the battery case, and acid is added for formation.