Positive unformed plate of flooded lead-acid storage battery for traction and manufacturing method of positive unformed plate

Abstract

The invention belongs to the technical field of lead-acid batteries, and particularly relates to a positive unformed plate of a flooded lead-acid storage battery for traction and a manufacturing method of the positive unformed plate. The positive unformed plate for the flooded traction lead-acid storage battery comprises a positive grid with plate lugs, positive lead plaster and a polyester thermal shrinkage bag, transverse ribs and vertical ribs are arranged in the positive grid, the positive lead plaster is thickly coated in the positive grid, and the polyester thermal shrinkage bag wraps the outer layers of the positive grid and the positive lead plaster to bind the positive lead plaster on the positive grid. According to the positive unformed plate of the lead-acid storage battery for the flooded traction, the lead plaster is prevented from falling off in a lead plaster supercoating and polyester thermal shrinkage bag coating mode, the service life of the positive unformed plate is prolonged, the working environment is improved, and the input cost of production equipment is reduced; the invention further provides a manufacturing method of the positive green plate of the flooded lead-acid storage battery for traction, and the manufacturing method is simple and easy to implement.

Description

Technical Field

[0001] The invention belongs to the technical field of lead-acid batteries, and in particular relates to a positive electrode plate of a flooded lead-acid traction battery and a manufacturing method thereof. Background Art

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

[0003] In order to meet the standard requirement of not less than 1000 cycles of cycle endurance test for flooded traction lead-acid batteries, domestic manufacturers use tubular positive plates to improve the utilization rate of positive active materials and prevent premature shedding of positive active materials, thereby increasing service life. However, the dry powder filling method is used to manufacture positive plates, which creates a harsh working environment and harms the health of front-line workers. At present, fully automatic paste extruders are used to produce positive plates, but this process still has obvious disadvantages: fully automatic paste extruders are expensive and the efficiency is only 1 / 10 of that of plate coating machines. When traditional plate positive plates are used for flooded traction lead-acid batteries, the thickness must reach 7mm-9mm, and the traditional over-coating is only 0.1-0.5mm. The surface is not rolled and raised, the contact area with the acid is small, and the utilization rate of active materials is low. At the same time, the plate spacing is large, and there is a lack of AGM separators that can bind active materials. Active materials are easy to fall off, resulting in a shortened battery life.

[0004] CN104577056A discloses a positive electrode plate for a lead-acid battery, which includes a grid frame, a lead paste and an acid-resistant porous coating layer. By combining the structural advantages of a tubular plate and a paste-coated plate, the grid-type positive electrode plate is not prone to softening and falling off of active substances, and the cycle service life is effectively extended; however, when the lead paste and the acid-resistant porous coating layer are sewn with acid-resistant sutures, the lead paste is easily caused to fall off, the sewing rate is low, and the equipment requirements are high. In addition, the plate is still a plate structure, the contact surface between the active substance and the electrolyte is not increased, and the utilization rate of the active substance is low. Summary of the invention

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

[0006] The positive electrode plate of the flooded lead-acid traction battery of the present invention comprises a positive grid with plate ears, a 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 outer layer of the positive grid and the positive lead paste to bind the positive lead paste to the positive grid.

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

[0008] Preferably, the positive grid is provided with horizontal ribs and vertical ribs, which form a grid structure in the positive 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 transverse reinforcement is less than the cross-sectional area of ​​the vertical reinforcement. Preferably, the cross-sectional area of ​​the transverse reinforcement is half of the cross-sectional area 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 tear strength of ≥100 N / cm, and a porosity of ≥50%.

[0010] The method for manufacturing the positive electrode plate of the flooded lead-acid traction battery comprises the following steps: S1: Apply positive lead paste to the positive grid, with the upper surface overcoated, and then roll it with a roller to obtain a positive plate with an arc-shaped convex surface, and the lower surface is not overcoated and has a flat structure; S2 pushes the coated positive electrode plate into a polyester heat shrink bag, and heat shrinks it through a heat shrink tunnel via a conveyor belt to obtain a positive electrode plate of a flooded lead-acid traction battery; wherein the polyester heat shrink bag tightly wraps the positive electrode plate after heat shrinkage, leaving only the plate ears completely exposed.

[0011] The single-sided overcoating thickness of the positive electrode lead paste is 4-6 mm.

[0012] The positive electrode plate has an arc-shaped protrusion on the surface, the protrusion center distance is 7-10mm, and the protrusion center and the center of the vertical rib cross section are on the same vertical line.

[0013] The temperature of the heat shrink tunnel is 80-110°C.

[0014] 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 overcoating, the cross section of the grooves is arc-shaped, and the radius is equal to half of the center distance between adjacent grooves (i.e., the center distance between the long strip protrusions on the surface of the green plate), and its structure is as follows: Figure 5 and Figure 6 shown.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) The positive electrode plate of the flooded lead-acid traction battery of the present invention adopts positive lead paste, which improves the working environment and reduces environmental pollution compared with the dry powder filling process; compared with the full-automatic paste extrusion process, it improves the production efficiency, reduces the investment cost of production equipment, and reduces the discharge of lead-containing wastewater; compared with the plate-type positive electrode plate, the contact area between the positive electrode plate and the electrolyte is increased, the utilization rate of the active material is improved, and the discharge capacity is increased. The positive electrode plate is over-coated, and the grid thickness is reduced by 30%-45% compared with the traditional positive electrode plate, which reduces the amount of grid alloy used and saves costs.

[0016] (2) The positive electrode plate of the flooded lead-acid traction battery of the present invention uses a polyester heat shrink bag to bind the positive electrode active material to the plate grid, thereby preventing the positive electrode active material from falling off and extending the service life of the positive electrode plate. At the same time, the polyester heat shrink bag tightly wraps the positive electrode plate after heat shrinkage, leaving only the plate ears completely exposed, thereby reducing the probability of short circuit of the positive electrode plate.

[0017] (3) The method for manufacturing the positive electrode plate of the flooded lead-acid traction battery of the present invention only requires over-coating and rolling one side of the positive electrode plate, and the preparation process is simple and the operation is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of the positive grid structure of the present invention; Figure 2 This is a schematic diagram of the positive electrode structure of the present invention when not covered with a polyester heat shrink bag; Figure 3 It is a schematic diagram of the structure of the polyester heat shrink bag of the present invention when the positive electrode plate is wrapped without heat shrinkage; Figure 4 It is a schematic diagram of the structure of the polyester heat shrink bag of the present invention when the positive electrode plate is wrapped and heat shrunk; Figure 5 is a side view of the roller used in the present invention; Figure 6 It is a surface development diagram of the roller used in the present invention.

[0019] In the figure: 1. Positive grid; 2. Positive electrode lead paste; 3. Polyester heat shrink bag; 4. Vertical ribs; 5. Horizontal ribs. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the embodiments and drawings. The raw materials used in the embodiments of the present invention are all commercially available conventional products unless otherwise specified, and the processes used are all conventional processes in the art. The polyester heat shrinkable bags used are commercially available polyester heat shrinkable fabrics purchased and made by ultrasonic welding.

[0021] like Figure 1-Figure 6As shown, the positive plate of the flooded lead-acid traction battery includes a positive grid 1 with plate ears, a positive lead paste 2, and a polyester heat shrink bag 3. The positive lead paste 2 is coated on the inside of the positive grid 1, and the polyester heat shrink bag 3 is wrapped around the outer layer of the positive grid 1 and the positive lead paste 2 to bind the positive lead paste 2 to the positive grid 1.

[0022] The frame thickness of the positive grid 1 is 4-6 mm.

[0023] The positive grid 1 is provided with transverse ribs 5 and vertical ribs 4, the number of the 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 transverse reinforcement 5 is less than the cross-sectional area of ​​the vertical reinforcement 4.

[0024] 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 tear strength of ≥100 N / cm, and a porosity of ≥50%.

[0025] The method for manufacturing the positive electrode plate of the flooded lead-acid traction battery comprises the following steps: S1: Apply positive lead paste 2 on positive grid 1, wherein the upper surface is overcoated, and the thickness of the single-side overcoating is 4-6mm, and then roll it with a roller to obtain a positive plate with arc-shaped convex surface, and the center distance of the convex is 7-10mm, and the lower surface is not overcoated, and has a flat structure; 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 beam, and the positive electrode plate is heat-shrunk through the heat shrink tunnel via a conveyor belt. The temperature of the heat shrink tunnel is 80-110°C, and the positive electrode plate of the flooded lead-acid traction battery is obtained; wherein, the polyester heat shrink bag 3 tightly covers the positive electrode plate after heat shrinkage, and only the plate ear is completely exposed.

[0026] Example 1 The positive plate of the flooded lead-acid traction battery described in this embodiment includes a positive grid 1 with a plate ear, a positive lead paste 2, and a polyester heat shrink bag 3. The positive lead paste 2 is coated on the inside of the positive grid 1, and the polyester heat shrink bag 3 is wrapped on the outer layer of the positive grid 1 and the positive lead paste 2 to bind the positive lead paste 2 to the positive grid 1; wherein 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 mm 2 The cross-sectional area of ​​the horizontal rib 5 is half of the cross-sectional area of ​​the vertical rib 4. The single-layer thickness of the polyester heat shrink bag 3 is 0.35 mm, the heat shrinkage rate is 40%, the tensile strength is 120 N / cm, and the porosity is 55%; The method for manufacturing the positive electrode plate of the flooded lead-acid traction battery comprises the following steps: S1 applies positive lead paste 2 on positive grid 1, wherein the upper surface is overcoated, and the thickness of the single-side overcoating is 4 mm, and then rolls it with a roller (the depth of the roller groove is 3 mm) to obtain a positive plate with an arc-shaped convex surface, and the center distance of the convex is 9.7 mm. The lower surface is not overcoated, and has a flat structure; 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 beam, and passes through the heat shrink tunnel through the conveyor belt for heat shrinkage, the temperature of the heat shrink tunnel is 100°C, and obtains the positive electrode plate of the flooded lead-acid traction battery; wherein, after heat shrinkage, the polyester heat shrink bag 3 tightly covers the positive electrode plate, and only the plate ear is completely exposed; The positive electrode plate manufactured using the above structure and method is made into 9PzS630H battery according to the existing process and tested in accordance with GB / T7403.1-2018: the first discharge capacity is 588Ah, and the fifth discharge capacity reaches 632Ah; the high-rate discharge time is 37min, the charge retention capacity test discharge capacity is 625Ah, and the cycle endurance has completed 1750 cycles. All indicators meet the standard requirements, and the production rate of the positive electrode plate is 70 pieces / min.

[0027] Example 2 The positive plate of the flooded lead-acid traction battery described in this embodiment includes a positive grid 1 with a plate ear, a 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 on the outer layer of the positive grid 1 and the positive lead paste 2 to bind the positive lead paste 2 to the positive grid 1; wherein the frame thickness of the positive grid 1 is 4.5 mm, the number of vertical ribs 4 is 15, the cross-sectional area of ​​the vertical ribs 4 is 4.5 mm², the cross-sectional area of ​​the horizontal ribs 5 is half of the cross-sectional area of ​​the vertical ribs 4, the single-layer thickness of the polyester heat shrink bag 3 is 0.30 mm, the heat shrinkage rate is 50%, the tensile strength is 100 N / cm, and the porosity is 60%; The method for manufacturing the positive electrode plate of the flooded lead-acid traction battery comprises the following steps: S1 applies positive lead paste 2 on positive grid 1, wherein the upper surface is overcoated, and the overcoating thickness of one side is 5 mm, and then rolls it with a roller (the roller groove depth is 4 mm), to obtain a positive plate with arc-shaped convex surface, and the convex center distance is 10 mm, and the lower surface is not overcoated, and has a flat structure; 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 beam, and passes through the heat shrink tunnel through the conveyor belt for heat shrinkage, the temperature of the heat shrink tunnel is 80°C, and obtains the positive electrode plate of the flooded traction lead-acid battery; wherein, after heat shrinkage, the polyester heat shrink bag 3 tightly covers the positive electrode plate, and only the plate ear is completely exposed; The positive electrode plate manufactured using the above structure and method is made into a 5DB500H battery according to the existing process and tested in accordance with GB / T7403.1-2018: the first discharge capacity is 490Ah, and the third discharge capacity reaches 503Ah; the high-rate discharge time is 35min, the charge retention capacity test discharge capacity is 500Ah, and the cycle endurance has completed 1650 cycles. All indicators meet the standard requirements, and the production rate of the positive electrode plate is 65 pieces / min.

[0028] Example 3 The positive plate of the flooded lead-acid traction battery described in this embodiment includes a positive grid 1 with plate ears, a 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 on the outer layer of the positive grid 1 and the positive lead paste 2 to bind the positive lead paste 2 to the positive grid 1; wherein, the frame thickness of the positive grid 1 is 4 mm, the number of vertical ribs 4 is 22, the cross-sectional area of ​​the vertical ribs 4 is 6 mm², the cross-sectional area of ​​the transverse ribs 5 is half of the cross-sectional area of ​​the vertical ribs 4, the single-layer thickness of the polyester heat shrink bag 3 is 0.5 mm, the heat shrinkage rate is 45%, the tensile strength is 130 N / cm, and the porosity is 52%.

[0029] The method for manufacturing the positive electrode plate of the flooded lead-acid traction battery comprises the following steps: S1 applies positive lead paste 2 on the positive grid 1, wherein the upper surface is over-coated, and the single-side over-coating thickness is 6mm, and then rolls it with a roller (the roller groove depth is 5mm) to obtain a positive electrode plate with an arc-shaped protrusion on the surface, and the protrusion center distance is 7mm. The lower surface is not over-coated and has a flat structure.

[0030] 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 beam, and the positive electrode plate is heat-shrunk through the heat shrink tunnel via a conveyor belt. The temperature of the heat shrink tunnel is 110°C, and the positive electrode plate of a flooded lead-acid traction battery is obtained; wherein, the polyester heat shrink bag 3 tightly covers the positive electrode plate after heat shrinkage, and only the plate ear is completely exposed.

[0031] The positive electrode plate manufactured using the above structure and method is made into D330KT (A) battery according to the existing process and tested in accordance with GB / T7403.1-2018: the first discharge capacity is 335Ah; the high-rate discharge time is 40min, the charge retention capacity test discharge capacity is 333Ah, and the cycle endurance has completed 1550 cycles. All indicators meet the standard requirements, and the production rate of the positive electrode plate is 85 pieces / min.

[0032] Comparative Example 1 The tubular positive electrode plate was prepared by the existing paste extrusion process, and a 9PzS630H battery was made according to the existing process, and tested according to GB / T7403.1-2018: the first discharge capacity was 600Ah, and the third discharge capacity reached 632Ah; the high-rate discharge time was 40min, the charge retention capacity test discharge capacity was 630Ah, and the cycle endurance completed 1800 cycles. All indicators met the standard requirements, and the production rate of the positive electrode plate was 7 pieces / min; the filling amount of the positive lead paste 2 in the positive electrode plate of this comparative example was the same as that in Example 1, the difference was that the conventional paste extrusion process was adopted in Comparative Example 1, which was to arrange the tube first and then extrude the paste.

[0033] Comparative Example 2 The plate-type positive electrode plate is manufactured by the existing process, and a 5DB500H battery is made according to the existing process, and is tested according to GB / T7403.1-2018: the first discharge capacity is 395Ah, and the 12th discharge capacity reaches 503Ah; the high-rate discharge time is 25min, the charge retention capacity test discharge capacity is 495Ah, and the cycle endurance has completed 700 cycles; the filling amount of the positive lead paste 2 in the positive electrode plate of this comparative example is the same as that in Example 2, except that there is no rolling and subsequent wrapping and heat shrinking steps, and only the conventional plate-type positive electrode plate preparation method is used to coat the positive lead paste 2.

[0034] The positive electrode plates prepared in Examples 1-3 and Comparative Examples 1-2 were applied to batteries and tested in accordance with GB / T7403.1-2018.

[0035] By comparing Example 1 with Comparative Example 1, the results show that although batteries with qualified performance can be prepared by the paste extrusion process, its production rate is low, which is not conducive to actual production; Comparative Example 2 is compared with Example 2, and the results show that the positive electrode plate prepared by simply coating the positive electrode lead paste 2 without rolling and subsequent wrapping and heat shrinking steps, even if the same amount of positive electrode lead paste 2 is used, its contact area with the acid solution is small, and the utilization rate of the active material in the positive electrode lead paste 2 is low. At the same time, the existing process does not restrain the positive electrode lead paste 2, which makes the active material easy to fall off. Ultimately, the battery produced by the plate-type positive electrode plate does not meet the national standard requirements.

Claims

1. A positive electrode plate of a flooded lead-acid traction battery, characterized in that: It comprises a positive grid (1) with plate ears, a positive lead paste (2), and a polyester heat shrink bag (3), wherein the positive lead paste (2) is coated on the positive grid (1), and the polyester heat shrink bag (3) is wrapped around the outer layer of the positive grid (1) and the positive lead paste (2), so as to bind the positive lead paste (2) to the positive grid (1).

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

3. The positive electrode plate of the flooded lead-acid traction battery according to claim 1, characterized in that: The positive grid (1) is provided with transverse ribs (5) and vertical ribs (4), the number of the vertical ribs (4) is 15-22, and the cross-sectional area of ​​the vertical ribs (4) is 4.5-6 mm 2 , the cross-sectional area of ​​the transverse reinforcement (5) is less than the cross-sectional area of ​​the vertical reinforcement (4).

4. The positive electrode plate of a flooded lead-acid traction battery according to claim 1, characterized in that: 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 tear strength of ≥100 N / cm, and a porosity of ≥50%.

5. A method for manufacturing a positive electrode plate of a flooded lead-acid traction battery according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: coating the positive lead paste (2) on the positive grid (1), wherein the upper surface is overcoated, and then rolling with a roller to obtain a positive electrode plate with an arc-shaped convex surface, and the lower surface is not overcoated and has a flat structure; S2 pushes the coated positive electrode plate into a polyester heat shrink bag (3), and heat shrinks the plate through a heat shrink tunnel via a conveyor belt to obtain a positive electrode plate for a flooded lead-acid traction battery.

6. The method for manufacturing a positive electrode plate of a flooded lead-acid traction battery according to claim 5, characterized in that: The single-sided overcoating thickness of the positive electrode lead paste (2) is 4-6 mm.

7. The method for manufacturing a positive electrode plate of a flooded lead-acid traction battery according to claim 5, characterized in that: The positive electrode plate has arc-shaped protrusions on the surface, and the protrusion center distance is 7-10mm.

8. The method for manufacturing a positive electrode plate of a flooded lead-acid traction battery according to claim 5, characterized in that: The temperature of the heat shrink tunnel is 80-110°C.

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