High-rate lead-acid storage battery grid structure and preparation method thereof

Abstract

The invention discloses a grid structure of a high-magnification lead-acid storage battery and a preparation method of the grid structure. The grid structure consists of a frame, tabs and composite ribs, the thickness of the tab is greater than that of the frame; the thickness of the frame is greater than that of the composite rib; the frame comprises an upper frame, a lower frame and a side frame; the composite ribs comprise short curved surface transverse ribs and long straight surface longitudinal ribs; the tab is located on the edge of one side of the upper frame, the short curved surface transverse ribs and the long straight surface longitudinal ribs are arranged in a brick wall type staggered mode, and the thicknesses of the tab, the frame and the ribs are designed in a gradient mode. Compared with the traditional grid structure, the grid structure disclosed by the invention can effectively reduce the current transmission impedance, obviously improve the discharge performance of the battery and provide a solid guarantee for high-rate charge and discharge application. The preparation method of the grid adopts a double-die step-by-step stamping process, so that the manufacturing process is simplified, and the production efficiency and the product consistency are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lead-acid storage batteries, in particular to a high-rate lead-acid storage battery grid structure and a preparation method thereof. BACKGROUND

[0002] With the rapid development of data centers, power systems and communication equipment, higher requirements are put forward for the short-time rate and high-power discharge performance of valve-regulated lead-acid batteries. Due to the limitation of manufacturing process, the traditional valve-regulated lead-acid battery usually adopts a relatively thick positive and negative plate design, which results in a small geometric area for electrochemical reaction and low output power, and it is difficult to meet the demand for high-power discharge in a short time.

[0003] In order to solve this problem, some manufacturers use a cast thin plate multi-piece design scheme to improve the high-power performance of the battery. However, this design scheme has some defects: due to the thin thickness of the plate, the thickness of the grid frame and the rib is also thin, the resistance to electrolyte corrosion is poor, the anti-deformation strength is poor, the plate is easy to deform and cause short circuit, which affects the service life of the battery. In addition, the unreasonable design of the grid structure will lead to the growth of the battery grid, affecting the cycle life and performance stability of the battery, and the design of the grid structure of the lead-acid battery still needs to be further optimized. At the same time, the traditional grid forming method has complicated steps, low production efficiency, and is prone to lead paste falling off during use, which affects the performance of the battery.

[0004] Therefore, a new grid structure design and manufacturing method is needed to improve the conductivity of the battery, enhance the strength of the plate, reduce the paste falling phenomenon, and prolong the service life of the battery. SUMMARY

[0005] The purpose of the present application is to solve the above technical problems, and to provide a new grid structure design and manufacturing method, which uses a double-die step-by-step stamping process to simplify the grid manufacturing process and significantly improve the production efficiency and product consistency. The specific technical scheme is as follows: A high-rate lead-acid storage battery grid structure, the grid structure is composed of a frame, a tab, and a composite rib; the thickness of the tab is greater than the thickness of the frame, and the thickness of the frame is greater than the thickness of the composite rib; the frame includes an upper frame, a lower frame, and a side frame, and the composite rib includes a horizontal rib and a vertical rib; the tab is located at one side edge of the upper frame, and the horizontal rib and the vertical rib are arranged in a brick wall type staggered manner; the vertical rib is a long straight face vertical rib, which is a hollow porous straight face structure; the horizontal rib is a short curved surface horizontal rib, which is a spiral curved surface structure; the grid structure is divided into a high-current area, a medium-current area, and a low-current area according to the current density gradient, the high-current area is located around the tab, the medium-current area is located in the middle of the grid, and the low-current area is located at the edge of the grid, and the rib density of each area is designed differently.

[0006] Preferably, the long straight surface longitudinal ribs are arranged inside the side frame in parallel to the side frame, and the two ends of each long straight surface longitudinal rib are connected perpendicularly to the upper and lower frames, and the short curved surface transverse ribs are arranged perpendicularly to the side frame and each short curved surface transverse rib connects two adjacent long straight surface longitudinal ribs or connects the vertical frame and the adjacent long straight surface longitudinal rib.

[0007] Preferably, the thickness of the tab is controlled in the range of 0.9 mm-1.1 mm, the thickness of the frame is controlled in the range of 0.8-0.9 mm, and the thickness of the composite rib is controlled in the range of 0.7-0.8 mm.

[0008] Preferably, the density of the high-current area is 8-10 roots / cm², the density of the medium-current area is 5-7 roots / cm², and the density of the low-current area is 3-4 roots / cm².

[0009] A preparation method of a high-rate lead-acid battery grid, the battery grid is prepared by a double-mold step-by-step stamping process, and the steps are as follows: Step 1: Lead strip preparation: a uniform-thickness lead strip is prepared by a continuous rolling process, the thickness is adjusted according to the design requirements of the grid, and the thickness gradient allowance of the tab, frame and composite rib is met to ensure that the lead strip surface is flat, free of impurities and oxidation layer, and provides a qualified base material for subsequent stamping forming; Step 2: First set of mold stamping: the plane basic structure is formed by conveying the lead strip into the first set of punching screen mold, removing the excess lead material by stamping process to form the plane basic structure of the grid; specifically including stamping out the profiles of the upper frame, lower frame and side frame to determine the overall size of the grid, stamping the distribution and shape of the long straight surface longitudinal ribs and the initial plane structure of the transverse ribs, at this time the transverse ribs have not formed a curved surface, and the transverse ribs and longitudinal ribs are arranged in a brick wall type staggered layout, that is, each transverse rib only connects two adjacent longitudinal ribs or the side frame and the adjacent longitudinal rib; simultaneously stamping out the tab located at the side edge of the upper frame to ensure the thickness gradient of the tab, frame and rib. Step 3: Second set of mold stamping: curved transverse rib forming, conveying the plane grid stamped in the first step into the second set of mold with concave-convex structure design for secondary stamping; using the concave-convex corresponding structure of the mold to apply directional pressure to the short transverse rib to make the originally flat short transverse rib plastically deform to form a pre-designed curved surface; keeping the structure of the frame, longitudinal rib and tab stable to ensure that the brick wall type staggered layout of the curved transverse rib and the longitudinal rib does not deviate, and at the same time ensuring the connection strength between the ribs.

[0010] Compared with the closest prior art, the technical scheme provided by the present application has the following beneficial effects: 1. The application adopts a curved transverse rib design, significantly extending the current conduction path of the rib in the polar plate; by shortening the conductive distance between the active material and the grid, the overall conductivity of the grid is greatly improved, compared with the traditional grid structure, which can effectively reduce the current transmission impedance and significantly improve the battery discharge performance, providing a solid guarantee for high-rate charge and discharge applications.

[0011] 2. Unlike the traditional straight rib flat grid, the curved grid significantly enhances the lead paste adhesion performance by increasing the surface area; this design not only improves the overall strength of the polar plate, but also effectively suppresses the occurrence of paste falling during use, greatly extending the service life of the battery and reducing the use and maintenance cost.

[0012] 3. The application can have more intersection points between the horizontal and vertical ribs of the grid under the same lead amount condition through the brick wall type rib net design, which is beneficial to enhance the overall strength of the grid and increase the active material adhesion area.

[0013] 4. The application adopts the double-die step stamping process through the division and cooperation of two stamping processes, which can not only accurately control the overall structure and rib distribution of the grid, but also optimize the curved surface shape of the short horizontal rib through secondary stamping, realizing the consideration of the stability and functionality of the grid structure, while simplifying the traditional multi-step forming process and improving the production efficiency and product consistency. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 The application provides a plan view of the battery grid; Figure 2 The application provides a horizontal cross-sectional view of the battery grid; Figure 1 In the figure: 1, upper frame; 2, lower frame; 3, side frame; 4, tab; 5, horizontal rib; 6, vertical rib. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0016] Please refer to Figures 1-2 .

[0017] A high rate lead-acid battery grid structure, the grid structure is composed of a frame, a tab, and a composite rib; the thickness of the tab 4 is greater than the thickness of the frame, and the thickness of the frame is greater than the thickness of the composite rib; the frame includes an upper frame 1, a lower frame 2, and a side frame 3, and the composite rib includes a horizontal rib 5 and a vertical rib 6; the tab 4 is located at one side edge of the upper frame 1, and the horizontal rib 5 and the vertical rib 6 are arranged in a brick wall type staggered layout; the vertical rib 6 is a long straight face vertical rib, which is a hollow porous straight face structure; the horizontal rib 5 is a short curved surface horizontal rib, which is a spiral curved surface structure; the grid structure is divided into a high current area, a medium current area, and a low current area according to the current density gradient, the high current area is located around the tab, the medium current area is located in the middle of the grid, and the low current area is located at the edge of the grid, and the rib density of each area is designed differently. By designing the brick wall type rib net, more intersection points can be formed between the horizontal and vertical ribs of the grid under the same lead amount, which is beneficial to enhancing the overall strength of the grid and increasing the active material adhesion area.

[0018] Further, the vertical rib 6 is arranged inside the side frame 3 parallel to the side frame 3, and the two ends of each vertical rib 6 are connected to the upper frame 1 and the lower frame 2 perpendicularly, and the horizontal rib 5 is arranged perpendicularly to the side frame 3 and each horizontal rib 5 connects two adjacent vertical ribs 6 or connects the vertical frame and its adjacent vertical rib 6. The curved surface horizontal rib design of the present application significantly prolongs the current conduction path of the rib in the plate; by shortening the conductive distance between the active material and the grid, the overall conductivity of the grid is greatly improved, compared with the traditional grid structure, the current transmission impedance can be effectively reduced, and the battery discharge performance can be significantly improved, providing a solid guarantee for high rate charging and discharging applications. Unlike traditional straight rib flat grid, the curved surface grid significantly enhances the lead paste adhesion performance by increasing the surface area; this design not only improves the overall strength of the plate, but also effectively suppresses the occurrence of paste falling during use, greatly prolongs the service life of the battery, and reduces the use and maintenance cost.

[0019] Further, the thickness of the tab 4 is controlled in the range of 0.9 mm-1.1 mm, the thickness of the frame is controlled in the range of 0.8-0.9 mm, and the thickness of the composite rib is controlled in the range of 0.7-0.8 mm.

[0020] Further, the high current area density is 8-10 roots / cm², the medium current area density is 5-7 roots / cm², and the low current area density is 3-4 roots / cm².

[0021] A high rate lead-acid battery grid preparation method, the battery grid is prepared by a double-mold step-by-step stamping process, and the steps are as follows: Step 1: Lead strip preparation: a continuous rolling process is used to prepare a lead strip with uniform thickness, the thickness is adjusted according to the design requirements of the grid, and the gradient thickness processing allowance of the tab 4, the frame and the composite rib is met to ensure that the lead strip surface is flat, free of impurities and oxidation layer, and to provide qualified base material for subsequent stamping forming; Step 2: First set of die stamping: plane base structure forming The lead belt is conveyed into the first set of punching net die, and the excess lead material is removed by the stamping process to form the plane base structure of the grid; specifically including stamping out the profiles of the upper frame 1, the lower frame 2, and the side frame 3 to determine the overall size of the grid, stamping the distribution and shape of the long straight face longitudinal rib and the initial plane structure of the 5 horizontal ribs, at this time the horizontal ribs 5 have not formed a curved surface, and the horizontal ribs 5 and the longitudinal ribs 6 are arranged in a brick wall type staggered layout, that is, each horizontal rib is connected to only two adjacent longitudinal ribs or the side frame and the adjacent longitudinal rib; the stamping of the tab located at the side edge of the upper frame is synchronized to ensure the thickness gradient of the tab, the frame, and the rib; Step 3: Second set of die stamping: curved horizontal rib forming The plane grid after the first step of stamping is conveyed into the second set of die with concave-convex structure design for secondary stamping; the concave-convex corresponding structure of the die is used to apply directional pressure to the short horizontal rib, causing the originally flat horizontal rib 5 to plastically deform and form a pre-designed curved surface; the structure of the frame, the longitudinal rib 6, and the tab is kept stable to ensure that the brick wall type staggered layout of the curved horizontal rib and the longitudinal rib does not deviate, and the connection strength between the ribs is also ensured.

[0022] The double-die step-by-step stamping process adopted by the present application achieves precise control of the overall structure of the grid and the distribution of the ribs through the division of labor of two stamping steps, and optimizes the curved shape of the short horizontal rib through secondary stamping, achieving the balance between the stability and functionality of the grid structure, while simplifying the traditional multi-step forming process and improving production efficiency and product consistency.

[0023] On the basis of the same other conditions, the discharge capacity of the assembled product 12V800W battery of the comparative example and the known battery grid is compared, and the results are as follows: Table 1 Comparison of discharge capacity of the grid of the example and the known battery As can be seen from the above table, the grid prepared by the preparation method of the present application has significantly improved discharge capacity compared to the general battery after subsequent assembly into a finished battery.

[0024] The above examples are only used to illustrate the technical solutions of the present application and not to limit them, although the present application has been described in detail with reference to the above examples, the ordinary skilled in the art can still modify or equivalently replace the specific embodiments of the present application, and any modification or equivalent replacement that does not deviate from the spirit and scope of the present application is within the protection scope of the claims of the application to be approved.

Claims

1. A high-rate lead-acid battery grid structure, characterized in that, The grid structure consists of a frame, tabs, and composite ribs. The thickness of the tabs is greater than the thickness of the frame, and the thickness of the frame is greater than the thickness of the composite ribs. The frame includes an upper frame, a lower frame, and a side frame. The composite ribs include horizontal ribs and vertical ribs. The tabs are located on one edge of the upper frame. The horizontal and vertical ribs are arranged in a brick wall-like staggered layout. The vertical ribs are long, straight-faced ribs with a hollow, porous, straight-faced structure. The horizontal ribs are short, curved-faced ribs with a helical curved-face structure. The grid structure is divided into a high-current region, a medium-current region, and a low-current region according to the current density gradient. The high-current region is located around the tabs, the medium-current region is located in the middle of the grid, and the low-current region is located at the edge of the grid. The rib density of each region is designed differently.

2. The high-rate lead-acid battery grid structure according to claim 1, characterized in that, The long straight longitudinal ribs are arranged parallel to the side frame and inside the side frame. The two ends of each long straight longitudinal rib are perpendicularly connected to the upper and lower frames respectively. The short curved horizontal ribs are arranged perpendicular to the side frame and each short curved horizontal rib connects to two adjacent long straight longitudinal ribs or connects the vertical frame to its adjacent long straight longitudinal ribs.

3. The high-rate lead-acid battery grid structure according to claim 1, characterized in that, The thickness of the electrode tab is controlled within the range of 0.9 mm to 1.1 mm, the thickness of the frame is controlled within the range of 0.8 to 0.9 mm, and the thickness of the composite rib is controlled within the range of 0.7 to 0.8 mm.

4. The high-rate lead-acid battery grid structure according to claim 1, characterized in that, The density in the high current region is 8-10 roots / cm², the density in the medium current region is 5-7 roots / cm², and the density in the low current region is 3-4 roots / cm².

5. A method for preparing a high-rate lead-acid battery grid according to any one of claims 1-4, characterized in that, The solar panel grid is manufactured using a dual-mold step-by-step stamping process, with the following steps: Step 1: Lead strip preparation: A lead strip with uniform thickness is prepared using a continuous rolling process. The thickness is adjusted according to the grid design requirements to meet the gradient thickness processing allowance of the tabs, frame and composite ribs, and to ensure that the lead strip surface is flat, free of impurities and oxide layer, so as to provide a qualified base material for subsequent stamping. Step 2: First set of die stamping: The lead strip is fed into the first set of die stamping, and excess lead is removed through the stamping process to form the planar basic structure of the grid. Specifically, this includes stamping out the outlines of the upper frame, lower frame, and side frame to determine the overall shape of the grid. The stamping forms the distribution and shape of the long straight longitudinal ribs and the initial planar structure of the transverse ribs. At this time, the transverse ribs have not yet formed curved surfaces, ensuring that the transverse and longitudinal ribs are arranged in a brick wall-like staggered layout, that is, each transverse rib connects only two adjacent longitudinal ribs or the side frame and the adjacent longitudinal rib. Simultaneously, the tabs located on one side edge of the upper frame are stamped out to ensure the thickness gradient of the tabs, frame, and ribs. Step 3: Second set of die stamping: Curved horizontal rib forming. The flat grid plate after the first step of stamping is transported to the second set of dies with concave and convex structure design for secondary stamping. Using the concave and convex structure of the die, directional pressure is applied to the short horizontal ribs, causing the originally flat short horizontal ribs to undergo plastic deformation and form a preset curved shape. The structure of the frame, longitudinal ribs and pole ears is kept stable to ensure that the brick wall-like staggered layout of the curved horizontal ribs and longitudinal ribs does not shift, while ensuring the connection strength between the ribs.

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