Rich liquid traction lead-acid battery positive plate and its manufacturing method

Abstract

The application belongs to the technical field of lead-acid batteries, and particularly relates to a positive active plate of a flooded traction lead-acid battery and a manufacturing method thereof. The positive active plate of the flooded traction lead-acid battery comprises a positive grid with a plate lug, positive lead paste and a polyester heat-shrink bag. The positive grid is provided with horizontal ribs and vertical ribs. The positive lead paste is thickly coated in the positive grid. The polyester heat-shrink bag is wrapped outside the positive grid and the positive lead paste to bind the positive lead paste to the positive grid. The positive active plate of the flooded traction lead-acid battery avoids the falling of the lead paste by means of the over-coating of the lead paste and the wrapping of the polyester heat-shrink bag, improves the service life of the positive active plate, improves the working environment and reduces the investment cost of the production equipment. The application also provides a manufacturing method of the positive active plate of the flooded traction lead-acid battery, which is simple and easy to implement.

Description

Technical Field

[0001] This invention belongs to the field of lead-acid battery technology, specifically relating to a positive electrode plate for a flooded traction lead-acid battery and its manufacturing method. Background Technology

[0002] Flooded lead-acid traction batteries are mainly used to provide DC power for handling vehicles, forklifts, etc. used in industrial and mining enterprises, warehouses, and stations.

[0003] To meet the standard requirement of at least 1000 cycles for the cycle durability test of flooded traction lead-acid batteries, domestic manufacturers use tubular positive electrode plates to improve the utilization rate of positive electrode active materials and prevent premature shedding, thereby extending service life. However, the dry-filling method for manufacturing positive electrode plates results in a harsh working environment, harming the health of frontline workers. Currently, fully automated paste extrusion machines are used for positive electrode plate production, but this process still has significant drawbacks: the equipment is expensive and its efficiency is only 1 / 10 that of a coating machine. When using traditional plate-type positive electrode plates for flooded traction lead-acid batteries, the thickness needs to reach 7mm-9mm, while traditional overcoating is only 0.1-0.5mm. The surface lacks roller-pressed protrusions, resulting in a small contact area with the acid and low utilization rate of active materials. Simultaneously, the large plate spacing and lack of AGM separators to bind the active materials make them prone to shedding, shortening battery life.

[0004] CN104577056A discloses a positive electrode plate for a lead-acid battery, which includes a grid frame, lead paste, and an acid-resistant porous coating layer. By combining the structural advantages of tubular electrode plates and paste-coated electrode plates, the resulting grid positive electrode plate is less prone to softening and shedding of active materials, effectively extending its cycle life. However, when acid-resistant stitches are used to sew the lead paste and the acid-resistant porous coating layer, the lead paste is prone to falling off, the sewing rate is low, and the equipment requirements are high. In addition, the electrode plate is still a plate structure, which does not increase the contact surface between the active material and the electrolyte, resulting in low utilization of the active material. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a positive electrode plate for a flooded traction lead-acid battery. By overcoating with lead paste and covering it with a polyester heat-shrink bag, the lead paste is prevented from falling off, the service life of the positive electrode plate is improved, the working environment is improved, and the investment cost of production equipment is reduced. This invention also provides a simple and easy method for manufacturing the positive electrode plate for a flooded traction lead-acid battery.

[0006] The positive electrode plate of the flooded traction lead-acid battery of the present invention includes a positive grid with lugs, positive lead paste, and a polyester heat shrink bag. The positive lead paste is coated on the positive grid, and the polyester heat shrink bag is wrapped around the positive grid and the positive lead paste, thus binding the positive lead paste to the positive grid.

[0007] Preferably, the thickness of the frame of the positive plate grid is 4-6mm.

[0008] Preferably, the positive plate grid is provided with horizontal and vertical ribs, which form a grid structure within the positive plate grid. The number of vertical ribs is 15-22, and the cross-sectional area of ​​the vertical ribs is 4.5-6 mm. 2 The cross-sectional area of ​​the horizontal reinforcement is less than that of the vertical reinforcement. Preferably, the cross-sectional area of ​​the horizontal reinforcement is half that of the vertical reinforcement.

[0009] Preferably, the polyester heat shrink bag has a single-layer thickness of 0.3-0.5 mm, a heat shrinkage rate of 40-50%, a tensile strength of ≥100 N / cm, and a porosity of ≥50%.

[0010] The method for manufacturing the positive electrode plate of the flooded traction lead-acid battery includes the following steps:

[0011] S1 applies positive electrode lead paste to the positive plate grid, with the upper surface overcoated, and then rolls it with rollers to obtain a positive electrode plate with an arc-shaped convex surface, while the lower surface is not overcoated, resulting in a planar structure.

[0012] S2 pushes the coated positive electrode plate into a polyester heat shrink bag, and then heat shrinks it through a heat shrink tunnel via a conveyor belt to obtain a positive electrode plate for a flooded traction lead-acid battery; wherein, after the polyester heat shrink bag is heat-shrinked, it tightly covers the positive electrode plate, with only the plate ears fully exposed.

[0013] The thickness of the positive electrode lead paste overcoating on one side is 4-6 mm.

[0014] The positive electrode plate with an arc-shaped protrusion has a center-to-center distance of 7-10mm, and the center of the protrusion is on the same vertical line as the center of the cross-section of the vertical rib.

[0015] The temperature of the heat-shrinkable tunnel is 80-110℃.

[0016] Preferably, the roller of the present invention has grooves on its surface. The depth of the grooves is 1 mm less than the thickness of the supercoating. The cross-section of the grooves is arc-shaped, and the radius is equal to half the center distance between adjacent grooves (i.e., the center distance between the elongated protrusions on the upper surface of the green electrode plate). Its structure is as follows: Figure 5 and Figure 6 As shown.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The positive electrode plate of the lead-acid battery for traction with rich liquid of the present invention adopts positive electrode lead paste, which improves the working environment and reduces environmental pollution compared with dry powder filling process; compared with fully automatic extrusion paste process, it improves production efficiency, reduces production equipment investment cost and reduces lead-containing wastewater discharge; compared with plate positive electrode plate, it increases the contact area between positive electrode plate and electrolyte, improves the utilization rate of active material and increases discharge capacity. The overcoating method of positive electrode plate reduces grid thickness by 30%-45% compared with traditional positive electrode plate, reduces grid alloy usage and saves costs.

[0019] (2) The positive electrode plate of the lead-acid battery for flooded traction of the present invention uses a polyester heat shrink bag to bind the positive electrode active material to the grid, which avoids the positive electrode active material from falling off and extends the service life of the positive electrode plate. At the same time, after the polyester heat shrink bag is heat-shrinked, it tightly covers the positive electrode plate, only exposing the plate ears completely, which can reduce the probability of short circuit of the positive electrode plate.

[0020] (3) The manufacturing method of the positive electrode plate of the lead-acid battery for flooded traction of the present invention only requires overcoating and rolling one side of the positive electrode plate. The preparation process is simple and convenient. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the positive plate grid structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the positive electrode plate structure of the present invention without the polyester heat shrink bag;

[0023] Figure 3 This is a schematic diagram of the structure of the present invention when the positive electrode plate is wrapped in a polyester heat-shrink bag without heat shrinking;

[0024] Figure 4 This is a schematic diagram of the structure of the present invention when the positive electrode plate is wrapped in a polyester heat-shrink bag and has been heat-shrinked.

[0025] Figure 5 This is a side view of the roller used in this invention;

[0026] Figure 6 This is a surface development view of the roller used in this invention.

[0027] In the diagram: 1. Positive grid; 2. Positive lead paste; 3. Polyester heat shrink bag; 4. Vertical rib; 5. Horizontal rib. Detailed Implementation

[0028] The present invention will be further described below with reference to the embodiments and accompanying drawings. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available conventional products, and the processes used are all conventional processes in the art. The polyester heat shrink bags used are made by purchasing commercially available polyester heat shrink fabric and manufacturing bags through ultrasonic welding.

[0029] like Figures 1-6 As shown, the positive electrode plate of the flooded traction lead-acid battery includes a positive grid 1 with lugs, positive lead paste 2, and a polyester heat shrink bag 3. The positive lead paste 2 is coated inside the positive grid 1, and the polyester heat shrink bag 3 is wrapped around the positive grid 1 and the positive lead paste 2, thus binding the positive lead paste 2 to the positive grid 1.

[0030] The thickness of the frame of the positive plate grid 1 is 4-6mm.

[0031] The positive plate grid 1 is provided with horizontal ribs 5 and vertical ribs 4. The number of vertical ribs 4 is 15-22, and the cross-sectional area of ​​the vertical ribs 4 is 4.5-6mm. 2 The cross-sectional area of ​​the horizontal reinforcement 5 is less than the cross-sectional area of ​​the vertical reinforcement 4.

[0032] The polyester heat shrink bag 3 has a single-layer thickness of 0.3-0.5mm, a heat shrinkage rate of 40-50%, a tensile strength of ≥100N / cm, and a porosity of ≥50%.

[0033] The method for manufacturing the positive electrode plate of the flooded traction lead-acid battery includes the following steps:

[0034] S1. Apply positive lead paste 2 to positive grid 1, with the upper surface overcoated and the thickness of the overcoat on one side being 4-6mm. Then roll it with rollers to obtain a positive electrode plate with an arc-shaped convex surface and a center-to-center distance of 7-10mm. The lower surface is not overcoated and has a planar structure.

[0035] S2 pushes the coated positive electrode plate into the polyester heat shrink bag 3. The lower edge of the polyester heat shrink bag 3 coincides with the lower edge of the bottom of the positive electrode plate, and the upper edge coincides with the upper edge of the upper crossbeam. It passes through the heat shrink tunnel via conveyor belt and is heat-shrinked. The temperature of the heat shrink tunnel is 80-110℃, resulting in the positive electrode plate of the flooded traction lead-acid battery. After heat shrinking, the polyester heat shrink bag 3 tightly covers the positive electrode plate, with only the plate ears fully exposed.

[0036] Example 1

[0037] The positive electrode plate of the flooded traction lead-acid battery described in this embodiment includes a positive grid 1 with lugs, positive electrode paste 2, and a polyester heat-shrink bag 3. The positive electrode paste 2 is coated inside the positive grid 1, and the polyester heat-shrink bag 3 wraps around the positive grid 1 and the positive electrode paste 2, binding the positive electrode paste 2 to the positive grid 1. The frame thickness of the positive grid 1 is 6 mm, the number of vertical ribs 4 is 19, and the cross-sectional area of ​​the vertical ribs 4 is 5.2 mm². 2 The cross-sectional area of ​​the horizontal rib 5 is half that of the vertical rib 4. The single-layer thickness of the polyester heat shrink bag 3 is 0.35mm, the heat shrinkage rate is 40%, the tensile strength is 120N / cm, and the porosity is 55%.

[0038] The method for manufacturing the positive electrode plate of the flooded traction lead-acid battery includes the following steps:

[0039] S1. Apply positive lead paste 2 to positive grid 1, with the upper surface overcoated and the thickness of the overcoat on one side being 4mm. Then roll it with a roller (the groove depth of the roller is 3mm) to obtain a positive electrode plate with an arc-shaped protrusion on the surface and a center distance of 9.7mm between the protrusions. The lower surface is not overcoated and has a planar structure.

[0040] S2 pushes the coated positive electrode plate into the polyester heat shrink bag 3. The lower edge of the polyester heat shrink bag 3 coincides with the lower edge of the bottom of the positive electrode plate, and the upper edge coincides with the upper edge of the upper crossbeam. It passes through the heat shrink tunnel via a conveyor belt and is heat-shrinked. The temperature of the heat shrink tunnel is 100℃, resulting in a positive electrode plate for a liquid-filled traction lead-acid battery. The polyester heat shrink bag 3 tightly covers the positive electrode plate after heat shrinking, with only the plate ears fully exposed.

[0041] The positive electrode plates manufactured using the above structure and method were used to make 9PzS630H batteries according to existing processes, and tested according to GB / T7403.1-2018: the initial discharge capacity was 588Ah, the capacity reached 632Ah after the 5th discharge, the high-rate discharge time was 37min, the discharge capacity of the charge retention test was 625Ah, and the cycle durability test completed 1750 cycles. All indicators met the standard requirements, and the production rate of the positive electrode plates was 70 pieces / min.

[0042] Example 2

[0043] The positive electrode plate of the flooded traction lead-acid battery described in this embodiment includes a positive grid 1 with lugs, positive electrode lead paste 2, and a polyester heat shrink bag 3. The positive electrode lead paste 2 is coated inside the positive grid 1, and the polyester heat shrink bag 3 wraps around the positive grid 1 and the positive electrode lead paste 2, binding the positive electrode lead paste 2 to the positive grid 1. The positive grid 1 has a frame thickness of 4.5 mm, 15 vertical ribs 4 with a cross-sectional area of ​​4.5 mm², and horizontal ribs 5 with a cross-sectional area half that of the vertical ribs 4. The polyester heat shrink bag 3 has a single-layer thickness of 0.30 mm, a heat shrinkage rate of 50%, a tensile strength of 100 N / cm, and a porosity of 60%.

[0044] The method for manufacturing the positive electrode plate of the flooded traction lead-acid battery includes the following steps:

[0045] S1. Apply positive lead paste 2 to positive grid 1, with the upper surface overcoated and the thickness of the overcoat on one side being 5mm. Then roll it with a roller (the groove depth of the roller is 4mm) to obtain a positive electrode plate with an arc-shaped protrusion on the surface and a center distance of 10mm between the protrusions. The lower surface is not overcoated and has a planar structure.

[0046] S2 pushes the coated positive electrode plate into the polyester heat shrink bag 3. The lower edge of the polyester heat shrink bag 3 coincides with the lower edge of the bottom of the positive electrode plate, and the upper edge coincides with the upper edge of the upper crossbeam. It passes through the heat shrink tunnel via a conveyor belt and is heat-shrinked. The temperature of the heat shrink tunnel is 80°C, resulting in a positive electrode plate for a liquid-filled traction lead-acid battery. The polyester heat shrink bag 3 tightly covers the positive electrode plate after heat shrinking, with only the plate ears fully exposed.

[0047] The positive electrode plates manufactured using the above structure and method were used to make 5DB500H batteries according to existing processes, and tested according to GB / T7403.1-2018: the initial discharge capacity was 490Ah, the third discharge capacity reached 503Ah; the high-rate discharge time was 35min, the discharge capacity of the charge retention test was 500Ah, and the cycle durability test completed 1650 cycles. All indicators met the standard requirements, and the production rate of the positive electrode plates was 65 pieces / min.

[0048] Example 3

[0049] The positive electrode plate of the flooded traction lead-acid battery described in this embodiment includes a positive grid 1 with lugs, positive lead paste 2, and a polyester heat shrink bag 3. The positive lead paste 2 is coated inside the positive grid 1, and the polyester heat shrink bag 3 wraps around the positive grid 1 and the positive lead paste 2, binding the positive lead paste 2 to the positive grid 1. The positive grid 1 has a frame thickness of 4mm, 22 vertical ribs 4, a cross-sectional area of ​​6mm², and a cross-sectional area of ​​half that of the vertical ribs 5. The polyester heat shrink bag 3 has a single-layer thickness of 0.5mm, a heat shrinkage rate of 45%, a tensile strength of 130N / cm, and a porosity of 52%.

[0050] The method for manufacturing the positive electrode plate of the flooded traction lead-acid battery includes the following steps:

[0051] S1 applies positive lead paste 2 onto the positive grid 1, with the upper surface overcoated to a thickness of 6mm on one side. Then, it is rolled with rollers (the groove depth of the rollers is 5mm) to obtain a positive electrode plate with an arc-shaped protrusion on the surface and a center-to-center distance of 7mm between the protrusions. The lower surface is not overcoated and has a planar structure.

[0052] S2 pushes the coated positive electrode plate into the polyester heat shrink bag 3. The lower edge of the polyester heat shrink bag 3 coincides with the lower edge of the bottom of the positive electrode plate, and the upper edge coincides with the upper edge of the upper crossbeam. It passes through the heat shrink tunnel via a conveyor belt and is heat-shrinked. The temperature of the heat shrink tunnel is 110℃, resulting in a positive electrode plate for a flooded traction lead-acid battery. After heat shrinking, the polyester heat shrink bag 3 tightly covers the positive electrode plate, with only the plate ears fully exposed.

[0053] The positive electrode plates manufactured using the above structure and method were used to make D330KT(A) batteries according to existing processes, and tested according to GB / T7403.1-2018: the initial discharge capacity was 335Ah; the high-rate discharge time was 40min; the discharge capacity of the charge retention test was 333Ah; the cycle durability test completed 1550 cycles; all indicators met the standard requirements; and the production rate of the positive electrode plates was 85 pieces / min.

[0054] Comparative Example 1

[0055] Tubular positive electrode plates were prepared using existing extrusion paste technology, and 9PzS630H batteries were manufactured according to the existing process. The batteries were tested according to GB / T7403.1-2018: the initial discharge capacity was 600Ah, the third discharge capacity reached 632Ah; the high-rate discharge time was 40min; the discharge capacity of the charge retention test was 630Ah; the cycle durability test completed 1800 cycles, and all indicators met the standard requirements. The production rate of positive electrode plates was 7 pieces / min. The amount of positive electrode lead paste 2 filled in the positive electrode plate of this comparative example was the same as that in Example 1. The difference was that the conventional extrusion paste process was used in Comparative Example 1, which involved first arranging the tubes and then extruding the paste.

[0056] Comparative Example 2

[0057] The plate-type positive electrode plate was manufactured using existing processes, and a 5DB500H battery was produced according to the existing processes. The battery was tested according to GB / T7403.1-2018: the initial discharge capacity was 395Ah, the 12th discharge capacity reached 503Ah; the high-rate discharge time was 25min, the discharge capacity of the charge retention test was 495Ah, and the cycle durability test completed 700 cycles. The positive electrode lead paste 2 filling amount in the positive electrode plate of this comparative example is the same as that in Example 2. The difference is that there is no rolling and subsequent heat shrinking steps. Only the conventional preparation method of plate-type positive electrode plate is used to coat the positive electrode lead paste 2.

[0058] The positive electrode plates prepared in Examples 1-3 and Comparative Examples 1-2 were applied to batteries and tested according to GB / T7403.1-2018.

[0059] Comparing Example 1 and Comparative Example 1, the results show that although the extrusion paste process can produce batteries with qualified performance, its production rate is low, which is not conducive to actual production. Comparing Comparative Example 2 with Example 2, the results show that the positive electrode plate prepared by simply coating the positive electrode paste 2 without rolling and subsequent heat shrinking steps has a small contact area with the acid, even if the same amount of positive electrode paste 2 is used. The utilization rate of the active material in the positive electrode paste 2 is low. At the same time, the existing process does not bind the positive electrode paste 2, which makes the active material easy to fall off. Ultimately, the battery produced by the plate positive electrode plate does not meet the national standard requirements.

Claims

1. A positive electrode plate for a flooded lead-acid traction battery, characterized in that, Includes a positive grid (1) with lugs, positive lead paste (2), and a polyester heat shrink bag (3). The positive lead paste (2) is coated on the positive grid (1), and the polyester heat shrink bag (3) is wrapped around the positive grid (1) and the positive lead paste (2) to bind the positive lead paste (2) to the positive grid (1). The positive plate grid (1) is provided with horizontal ribs (5) and vertical ribs (4), the number of vertical ribs (4) is 15-22, and the cross-sectional area of ​​the vertical ribs (4) is 4.5-6mm. 2 The cross-sectional area of ​​the horizontal reinforcement (5) is less than the cross-sectional area of ​​the vertical reinforcement (4); The polyester heat shrink bag (3) has a single-layer thickness of 0.3-0.5 mm, a heat shrinkage rate of 40-50%, a tensile strength of ≥100 N / cm, and a porosity of ≥50%. The method for manufacturing the positive electrode plate of the flooded traction lead-acid battery includes the following steps: S1 The positive electrode lead paste (2) is applied to the positive plate grid (1), with the upper surface overcoated and then rolled with rollers to obtain a positive electrode plate with an arc-shaped protrusion on the surface. The lower surface is not overcoated and has a planar structure. The thickness of the positive electrode lead paste (2) overcoated on one side is 4-6mm. The center of the protrusion and the center of the cross section of the vertical rib are on the same vertical line. S2 pushes the coated positive electrode plate into a polyester heat shrink bag (3), and heat shrinks it through a heat shrink tunnel via a conveyor belt to obtain the positive electrode plate of a liquid-filled traction lead-acid battery.

2. The positive electrode plate of the flooded traction lead-acid battery according to claim 1, characterized in that, The thickness of the frame of the positive plate grid (1) is 4-6mm.

3. The positive electrode plate of the flooded traction lead-acid battery according to claim 1, characterized in that, The positive electrode plate has an arc-shaped convex surface with a center-to-center distance of 7-10 mm.

4. The positive electrode plate of the flooded traction lead-acid battery according to claim 1, characterized in that, The temperature of the heat-shrinkable tunnel is 80-110℃.

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