Positive green plate and manufacturing method thereof

Abstract

The invention discloses a positive unformed plate and a manufacturing method thereof, and relates to the technical field of lead storage batteries. On the premise of ensuring the product quality, a high-apparent-density lead paste formula is adopted, the strongly acidic styrene cation exchange resin is added in the formula, the lead paste is good in flowability, an acid-free rapid paste mixing process is matched, no excessive water is separated out in the paste extrusion process, and a lead paste recovery treatment system does not need to be matched; in addition, sulfuric acid is not added in the lead paste formula, chemical reaction is avoided, paste mixing equipment does not need to adopt cooling measures of water cooling or air cooling, acid-resistant and corrosion-resistant materials are not needed, and the manufacturing cost of the paste mixing equipment is reduced. Meanwhile, a positive unformed plate curing procedure is cancelled, so that the processing technology is simplified, and the production cost of the battery is reduced; the high-rate discharge performance of the lead storage battery assembled by adopting the positive unformed plate manufactured by the invention is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lead-acid batteries, and particularly to a positive grid plate and a manufacturing method thereof. Background Art

[0002] There are mainly three manufacturing methods for the positive grid plates of tubular lead-acid batteries, namely powder filling type, paste extrusion type, and grout filling type. The paste extrusion production method mainly fills the lead paste into a pre-prepared tubular grid (a sleeve is installed on the rib of the grid plate) by extrusion. The production of this process requires the use of special paste extrusion equipment to extrude the pre-prepared lead paste into the tubular grid at a certain pressure and speed, install the bottom seal, and send it into a curing and drying kiln for curing and drying.

[0003] When the lead paste is extruded into the tubular grid, in order to ensure the uniform distribution and filling rate of the lead paste in the grid, parameters such as extrusion pressure, speed, and fluidity of the lead paste need to be controlled. If the fluidity of the lead paste is poor and the extrusion pressure is too high, it may cause the sleeve of the tubular grid to rupture or deform, resulting in the leakage of active substances, leading to battery short circuit or increased self-discharge; it will also cause uneven paste extrusion volume, resulting in phenomena such as flattened tubes or empty tubes. Therefore, in order to manufacture lead paste with good fluidity, the apparent density of the lead paste is generally controlled at 3.2 - 3.7 g / cm 3 , but at this density, the water content in the lead paste is relatively high. When the lead paste is extruded into the tubular grid, some of the water in the lead paste will precipitate from the holes of the sleeve under the action of pressure (the apparent density of the lead paste in the sleeve is 4.8 - 5.1 g / cm 3 ), and a lot of lead sludge will accompany the precipitation of water, resulting in a dirty surface of the sleeve, which needs to be cleaned. If the cleaning is not thorough, it will increase the internal resistance of the battery and reduce the battery performance. Therefore, usually, a large amount of water is used to clean the surface of the sleeve, and a special lead paste recovery and treatment system is provided.

[0004] The lead paste recovery and treatment system mainly consists of a recovery tank, a sedimentation tank, a clean water tank, a stirring tank, etc. A stirring system is provided in the recovery tank. To prevent the precipitation of lead sludge, the stirring system cannot be stopped; a clean water and lead sludge separation device is provided in the sedimentation tank. After separation, the lead sludge is pumped into the stirring tank, and the clean water is pumped into the clean water tank; a stirring system is provided in the stirring tank. After the lead sludge and an appropriate amount of clean water are fully stirred, when the density reaches the process requirements, the mixture in the stirring tank is transported to the paste mixer at a certain addition amount. The lead paste recovery and treatment system realizes the recycling of sludge and achieves the purpose of zero discharge. However, the system operation is relatively complex, bringing many inconveniences to production and operation. Especially for the lead pump in the stirring system, in order to prevent the precipitation of lead sludge, the stirring lead pump cannot be stopped, which puts higher requirements on the reliability of the equipment and also wastes a large amount of electric energy.

[0005] In addition, the traditional paste extrusion process uses a lead paste formula mainly consisting of lead powder, sulfuric acid, water, and additives. During the lead paste mixing process, a chemical reaction occurs between sulfuric acid and lead powder, releasing a large amount of heat. To prevent the paste mixing temperature from exceeding 60°C, the acid addition time is usually controlled within 15 - 20 minutes. Therefore, the time required to mix a box of lead paste is not less than 30 minutes, and relatively high requirements are imposed on the paste mixing equipment, which must be acid-resistant and equipped with two sets of cooling devices, namely air cooling and water cooling. At the same time, when using this process to produce lead paste, during the reaction between lead powder and sulfuric acid, basic lead sulfate is generated, making the structure of the lead paste denser and the hardness relatively greater. When the apparent density of the lead paste is higher than 3.8 g / cm 3 and the penetration of the lead paste is less than 45 mm, the process performance during paste extrusion is not ideal, and phenomena such as tube swelling, empty tubes, flattened tubes, and the paste extrusion amount not being within the process requirements are likely to occur.

[0006] Therefore, there is an urgent need to develop a new manufacturing method to solve the above problems existing in the current manufacturing method of positive raw plates. Summary of the Invention

[0007] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art and provide a positive raw plate and its manufacturing method. On the premise of ensuring product quality, a high-apparent-density lead paste formula and a fast acid-free paste mixing process are adopted, no excess water is separated out during the paste extrusion process, and there is no need to support a lead paste recycling and treatment system. At the same time, the curing process of the positive raw plate is cancelled, simplifying the processing technology and reducing the battery production cost. For the lead-acid battery assembled with the positive raw plate manufactured by the present invention, the high-rate discharge performance is greatly improved.

[0008] The technical solution of the present invention is as follows: On the one hand, the present invention provides a manufacturing method for a positive raw plate, including the following steps: S1 Prepare lead paste: The lead paste is made from the following raw materials in parts by weight: 100 parts of lead powder, 4 - 5 parts of strongly acidic styrene-based cation exchange resin, 0.5 - 1 part of nano-silica, and 9.3 - 10.5 parts of deionized water; the preparation method of the lead paste is: add the strongly acidic styrene-based cation exchange resin, nano-silica, and 50 parts of lead powder into a paste mixer for the first-stage stirring; then add the remaining 50 parts of lead powder for the second-stage stirring; then pour deionized water into the paste mixer, and conduct the third-stage stirring while pouring water, and the stirring speeds of the three stages gradually increase, thus obtaining lead paste with an apparent density of 4.8 - 5.1 g / cm 3 ; S2 Acid immersion: Squeeze the lead paste into a tubular grid frame, install the bottom seal, and immerse it in sulfuric acid electrolyte with a density of 1.6 - 1.65 g / cm 3 ; S3 Drying: After pickling, it is sent into a drying kiln for drying. The humidity in the first stage of drying is 60 - 75%RH, the temperature is 50 - 60°C, and the time is 6 - 8h; the humidity in the second stage of drying is ≤20%RH, the temperature is 70 - 80°C, and the time is 16 - 18h, then the positive grid plate is obtained.

[0009] Preferably, in step S1, the strongly acidic styrene-based cation exchange resin is the 001X7H type strongly acidic styrene-based cation exchange resin.

[0010] Preferably, in step S1, the particle size of the strongly acidic styrene-based cation exchange resin is 0.3 - 0.6mm.

[0011] Preferably, in step S1, the rotation speed of stirring in the first stage is 15 - 20rpm to uniformly coat the lead powder with the strongly acidic styrene-based cation exchange resin; the rotation speed of stirring in the second stage is 30 - 40rpm to form a "lead powder - resin" core - shell structure; the rotation speed of stirring in the third stage is 60 - 80rpm to trigger the swelling of the strongly acidic styrene-based cation exchange resin and release lubricity.

[0012] Preferably, the stirring time in the first stage is 1 - 1.5min, the stirring time in the second stage is 1 - 1.5min, the time for pouring in deionized water is 3 - 5min, and the stirring time in the third stage is 5 - 8min.

[0013] Preferably, in step S1, the total paste - making time is 7 - 11min.

[0014] Preferably, in step S2, the pickling time is 3 - 5s.

[0015] On the other hand, the present invention provides a positive grid plate obtained by the manufacturing method of the above positive grid plate.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The paste manufactured by the present invention through the high apparent density paste formula and the acid - free rapid paste - making process has good fluidity. When the paste is extruded into the tubular grid, the moisture in the paste will not precipitate from the holes of the sleeve under the action of pressure, and the surface of the sleeve is clean, without the need for cleaning, so there is no need to support a paste recovery and treatment system, which simplifies the paste extrusion processing technology.

[0017] 2. By adopting the acid - free rapid paste - making process of the present invention, the paste - making time is greatly shortened, and the equipment utilization rate is improved. At the same time, since sulfuric acid is not required to be added during the paste manufacturing process, the paste - making equipment does not need to be acid - proof treated or made of acid - proof materials, reducing the manufacturing cost of the equipment.

[0018] 3. The lead-acid battery assembled with the positive grid plate manufactured by the present invention can be comparable to the lead-acid battery manufactured by the traditional process, and its high-rate discharge performance is even more excellent. This is because during high-rate discharge of the traditional positive grid plate, the concentration of H + in the pores of the grid plate drops rapidly, but the H + in the external electrolyte cannot diffuse and supplement in time, resulting in the reaction stagnation due to acid deficiency inside the grid plate and a sudden voltage drop ("knee point effect"), and the discharge is terminated prematurely. When the present invention uses strongly acidic styrene-based cation exchange resin as an additive, its mechanism of action is as follows: during high-rate discharge of the battery, due to the rapid decrease in the concentration of H + in the micropores of the positive active material, when the diffusion rate of sulfuric acid cannot keep up, the H + in the strongly acidic styrene-based cation exchange resin exchanges with Pb 2+ in the solution, adsorbs Pb 2+ , and releases H + , thereby increasing the concentration of H + in the micropores of the positive grid plate and increasing the discharge capacity. During discharge end and the charging process, due to the diffusion effect, the concentration of H + in the micropores of the positive active material gradually increases, and exchanges with Pb 2+ adsorbed by the strongly acidic styrene-based cation exchange resin, restoring the original state of the strongly acidic styrene-based cation exchange resin.

[0019] 4. The present invention adds nano-silica to the lead paste formula of the positive grid plate. The hydroxyl groups on its surface form a hydrogen bond network with the sulfonic acid groups of the strongly acidic styrene-based cation exchange resin, and water molecules are trapped in the hydrogen bond network, preventing the lead paste from dehydrating too quickly and avoiding the problem of drying and cracking of the high-density lead paste.

[0020] 5. The present invention enables (1) high-density (1.6 - 1.65 g / cm 3 ) sulfuric acid to rapidly sulfonate the surface layer of the lead paste within 3 - 5 s to form a dense PbSO4 layer, which can enhance the mechanical strength of the positive grid plate; (2) in the first stage of drying, the strongly acidic styrene-based cation exchange resin absorbs heat and expands, and the internal water diffuses in a gradient manner. In the second stage of drying, the strongly acidic styrene-based cation exchange resin dehydrates and shrinks, extruding the lead powder particles and enhancing the binding force, thereby realizing that the performance of the positive grid plate manufactured after canceling the curing process is not lower than that of the traditional cured product, and simplifying the production process. Detailed Embodiments

[0021] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention.

[0022] In the following embodiments: 001X7H strongly acidic styrene-based cation exchange resin, Zibo Dongda Chemical Co., Ltd.; Nano-silica, Wuxi Hengcheng Silicon Industry Co., Ltd.; Lead powder, self-made in the laboratory.

[0023] Example 1 The manufacturing method of the 5DB500 positive grid plate in this example includes the following steps: S1 Prepare the lead paste: Add 40 kg of 001X7H strongly acidic styrene-based cation exchange resin (particle size 0.3 mm), 5 kg of nano-silica and 500 kg of lead powder into the paste mixer, stir at 15 rpm for 1 min; then add another 500 kg of lead powder, stir at 30 rpm for 1 min; then pour 93 kg of deionized water into the paste mixer, the pouring time is 3 min, adjust the stirring speed to 60 rpm while pouring water, and stir at this speed for 5 min, stop the machine and test the apparent density of the lead paste to be 5.1 g / cm 3 , thus obtaining the lead paste; S2 Acid immersion: Use the die-casting mold of the 5DB500 lead storage battery to die-cast 4800 positive grid plates. Install the ribs of the die-cast positive grid plates into the polyester tubes using a casing machine. Send the semi-finished positive grid plates with installed polyester tubes to the paste extruder, extrude the lead paste, the extrusion amount is 1468 g / piece, and then automatically install the plastic bottom seal to obtain the wet positive grid plate; Place the wet positive grid plate in an acid tank with sulfuric acid density of 1.6 g / cm 3 , soak for 3 s, take out the positive grid plate after soaking and place it on the drying rack; S3 Drying: Send the drying rack with the positive grid plates to the drying kiln for drying. The humidity in the first stage of drying is 60%RH, the temperature is 50 °C, and the time is 6 h; the humidity in the second stage of drying is 20%RH, the temperature is 70 °C, and the time is 16 h, thus obtaining the positive grid plate, and the water content of the positive grid plate is 0.5 wt.%.

[0024] Assemble the positive grid plates manufactured in this example into a 5DB500 lead storage battery.

[0025] Example 2 The manufacturing method of the 5PzS625 positive grid plate in this example includes the following steps: S1 Preparation of lead paste: Add 45 kg of 001X7H type strong acid styrene cation exchange resin (particle size 0.45 mm), 7.5 kg of nano-silica and 500 kg of lead powder to a paste mixer and stir at 17.5 rpm for 1.25 min; then add 500 kg of lead powder and stir at 35 rpm for 1.25 min; then pour 97 kg of deionized water into the paste mixer for 4 min. While pouring water, adjust the stirring speed to 70 rpm and stir at this speed for 6.5 min. Stop the machine to test the apparent density of the lead paste, which is 4.95 g / cm 3 , you get lead paste; S2 acid dipping: Use the die-casting mold of 5PzS625 lead-acid battery to die-cast 2400 positive grids. Use the casing machine to install the ribs of the die-cast positive grid in the polyester tube. Send the semi-finished positive grid with the polyester tube installed to the paste extruder, squeeze in the lead paste, the paste amount is 1810g / piece, and then automatically install the plastic bottom to obtain the wet positive plate; put the wet positive plate into the slurry containing sulfuric acid with a density of 1.65g / cm 3 Soak the positive plates in an acid tank for 4 seconds. After soaking, take out the positive plates and place them on a drying rack. S3 Drying: Send the drying rack with the positive plates to the drying kiln for drying. The humidity of the first drying stage is 67% RH, the temperature is 55°C, and the time is 7 hours. The humidity of the second drying stage is 15% RH, the temperature is 75°C, and the time is 17 hours. The positive plates are obtained, and the moisture content of the positive plates is 0.4wt.%.

[0026] The positive electrode plates manufactured in this embodiment were assembled into a lead-acid battery of model 5PzS625.

[0027] Example 3 The manufacturing method of the D-450 positive electrode plate of this embodiment includes the following steps: S1 Preparation of lead paste: Add 50 kg of 001X7H type strong acid styrene cation exchange resin (particle size 0.6 mm), 10 kg of nano-silica and 500 kg of lead powder to a paste mixer and stir at 20 rpm for 1.5 min; then add 500 kg of lead powder and stir at 40 rpm for 1.5 min; then pour 105 kg of deionized water into the paste mixer for 5 min. While pouring water, adjust the stirring speed to 80 rpm and stir at this speed for 8 min. Stop the machine to test the apparent density of the lead paste, which is 4.8 g / cm 3 , you get lead paste; S2 Acid Dipping: Using a die-casting mold for D-450 lead-acid batteries, die-cast 4800 positive plate grids. The die-cast positive plate grids are installed with ribs in a polyester row tube using a casing machine. The semi-finished positive plate grids with the installed polyester row tubes are sent to a paste extruder, and lead paste is extruded with an extrusion amount of 730 g / grid. Then, a plastic bottom cover is automatically installed to obtain a wet positive plate. The wet positive plate is placed in an acid tank with a sulfuric acid density of 1.65 g / cm 3 and soaked for 5 s. After soaking, the positive plate is taken out and placed on a drying rack. S3 Drying: The drying rack with the positive plates placed on it is sent to a drying kiln for drying. The humidity in the first stage of drying is 75%RH, the temperature is 60 °C, and the time is 8 h. The humidity in the second stage of drying is 10%RH, the temperature is 80 °C, and the time is 18 h, thus obtaining the positive plates with a water content of 0.25 wt.%.

[0028] Assemble the positive plates manufactured in this example into a lead-acid battery of model D-450.

[0029] Comparative Example 1 The manufacturing method of the 5DB500 positive plates in Comparative Example 1 includes the following steps: S1 Manufacturing Recycled Lead Paste: Transport the lead sludge and clear water in the lead paste recycling system to a stirring tank and adjust its density to 1.8 g / cm 3 for standby. S2 Manufacturing Lead Paste: Add 500 kg of lead powder and 500 kg of red lead to a paste mixer and stir at 50 rpm for 3 min. Add 110 kg of deionized water and stir at 50 rpm for 3 min. While stirring, add 100 kg of sulfuric acid with a density of 1.4 g / cm 3 to the paste mixer within 15 min. After adding the acid, continue stirring for 10 min to obtain lead paste with an apparent density of 4.25 g / cm 3 . To prevent the temperature in the paste mixer from exceeding 60 °C during the paste mixing process, starting from the sulfuric acid addition stage, two systems for cooling water and air cooling of the paste mixer need to be turned on. When the temperature of the lead paste in the paste mixer is lower than 38 °C, add 220 kg of the recycled lead paste from step S1 to the paste mixer and continue stirring at 50 rpm for 10 min. Test the apparent density of the lead paste to be 3.2 g / cm 3 ; S3 Paste Extrusion: Using a die-casting mold for 5DB500 lead-acid batteries, die-cast 4800 positive plate grids. The die-cast positive plate grids are installed with ribs in a polyester row tube using a casing machine. The semi-finished positive plate grids with the installed polyester row tubes are sent to a paste extruder, and lead paste is extruded with an extrusion amount of 1590 g / grid. Then, a plastic bottom cover is automatically installed to obtain a wet positive plate. Then, the wet positive plate is sent to a cleaning station to clean the lead sludge on the surface of the positive plate. S4 Curing and Drying: Send the wet positive grid plate after surface cleaning to the curing and drying kiln, and cure and dry the positive grid plate according to the curing and drying parameters shown in Table 1-2, then the positive grid plate is obtained, and the water content of the positive grid plate is 0.5 wt.%.

[0030] Table 1 Curing Parameters of the Positive Grid Plate in Comparative Example 1

[0031] Table 2 Drying Parameters of the Positive Grid Plate in Comparative Example 1

[0032] Assemble the positive grid plate manufactured in Comparative Example 1 into a lead-acid battery with the model of 5DB500.

[0033] Comparative Example 2 The difference from Example 1 is that in step S1, 001X7H type strongly acidic styrene-based cation exchange resin is not added.

[0034] Comparative Example 3 The difference from Example 1 is that in step S1, D201 type strongly basic anion exchange resin (particle size of 0.3 mm) is used to replace the 001X7H type strongly acidic styrene-based cation exchange resin in Example 1.

[0035] Comparative Example 4 The difference from Example 1 is that in step S1, the addition amount of 001X7H type strongly acidic styrene-based cation exchange resin is 55 kg.

[0036] Comparative Example 5 The difference from Example 1 is that in step S1, nano-silica is not added.

[0037] Comparative Example 6 The difference from Example 1 is that in step S1, the addition amount of nano-silica is 15 kg.

[0038] Comparative Example 7 The difference from Example 1 is that in step S1, the 001X7H type strongly acidic styrene-based cation exchange resin, nano-silica, lead powder and deionized water are added to the paste mixer at one time and stirred together, and the stirring speed is 60 rpm.

[0039] Comparative Example 8 The difference from Example 1 is that in step S1, the stirring speed of the paste mixer is always 80 rpm.

[0040] Comparative Example 9 The difference from Example 1 is that in step S1, the amount of deionized water poured in is 72.5 kg, and the apparent density of the lead paste obtained is 5.5 g / cm 3 .

[0041] Comparative Example 10 The difference from Example 1 is that in step S2, the sulfuric acid density in the acid tank is 1.75 g / cm 3 .

[0042] Comparative Example 11 The difference from Example 1 is that in step S3, the drying rack for placing the positive green plates is sent to a drying kiln for drying. The drying humidity is 20%RH, the temperature is 70 °C, and the time is 22 h, thus obtaining the positive green plates, and the water content of the positive green plates is 0.01 wt.%.

[0043] The lead-acid batteries assembled with Examples 1-3 and Comparative Examples 1-11 were subjected to performance tests. The tests were carried out with reference to "GB / T7403.1-2018 Traction Lead-Acid Batteries Part 1: Technical Conditions". The test results are shown in Table 3 as follows: Table 3 Performance test results of the lead-acid batteries assembled with Examples 1-3 and Comparative Examples 1-11

[0044] In Table 3, the first discharge capacity / rated capacity refers to the percentage of the actual capacity in the first capacity test to the rated capacity; the discharge capacity / rated capacity refers to the percentage of the highest actual capacity to the rated capacity in the first ten capacity tests.

[0045] It can be seen from Table 3 that the initial capacities of the lead-acid batteries of Examples 1-3 and Comparative Example 1 all meet the requirements of "GB / T7403.1-2018 Traction Lead-Acid Batteries Part 1: Technical Conditions". And compared with the lead-acid batteries manufactured by the existing manufacturing method in Comparative Example 1, the capacities of the lead-acid batteries of Examples 1-3 are comparable to it, and the high-rate discharge performance is more excellent. At the same time, since the positive green plates were not cured during the manufacturing process of Examples 1-3, the processing technology was simplified.

[0046] Compared with Example 1, the first capacity and the highest capacity in the first ten capacity tests of the lead-acid battery manufactured in Comparative Example 2 are basically the same, but the high-rate discharge performance drops by about 13.6%, indicating that adding strongly acidic styrene-based cation exchange resin can improve the rate discharge performance. The first capacity, the highest capacity in the first ten capacity tests, and the high-rate discharge performance of the lead-acid battery manufactured in Comparative Example 3 all decrease significantly. This is because the anions on the D201 type strongly basic anion exchange resin will compete for the transport channels with SO4 2- in the electrolyte, causing lead ions and SO4 2-The reaction that combines to form PbSO4 is hindered, affecting the charge and discharge performance of the battery. The first capacity of the lead-acid battery manufactured in Comparative Example 4, the highest capacity in the first ten capacity tests, and the high-rate discharge performance are comparable to those of Example 1, indicating that adding too much strongly acidic styrene-based cation exchange resin does not improve the battery performance but increases the manufacturing cost instead. The first capacity of the lead-acid battery manufactured in Comparative Example 5, the highest capacity in the first ten capacity tests, and the high-rate discharge performance are all significantly reduced, and during the first ten capacity tests, the capacity does not reach the standard requirement value, indicating that the lead paste without adding nano-silica has a fast drying speed, resulting in uneven shrinkage of the lead paste, cracking of the lead paste on the plate surface, and affecting the battery capacity. The first capacity of the lead-acid battery manufactured in Comparative Example 6, the highest capacity in the first ten capacity tests, and the high-rate discharge performance are all significantly reduced, and the high-rate discharge performance does not meet the standard requirement because nano-silica itself is insulating, and excessive addition may lead to a decrease in the overall conductivity of the electrode.

[0047] Compared with Example 1, the first capacity of the lead-acid battery manufactured in Comparative Example 7, the highest capacity in the first ten capacity tests, and the high-rate discharge performance are all significantly reduced, and the first capacity is the highest, indicating that the lead paste obtained by this pasting method has uneven composition and affects the battery performance. The first capacity of the lead-acid battery manufactured in Comparative Example 8, the highest capacity in the first ten capacity tests, and the high-rate discharge performance are slightly reduced, indicating that the dry mixing and stirring speed before adding water is too high, causing some strongly acidic styrene-based cation exchange resins to be damaged and affecting the battery performance. The first capacity of the lead-acid battery manufactured in Comparative Example 9, the highest capacity in the first ten capacity tests, and the high-rate discharge performance are all significantly reduced, and the highest capacity in the first ten capacity tests does not reach the standard requirement because the lead paste manufactured by this process has a too high apparent density of the lead paste, making it difficult to extrude the paste, and the phenomenon of swelling tubes and empty tubes appears in the manufactured positive grids, affecting the battery capacity. The first capacity of the lead-acid battery manufactured in Comparative Example 10, the highest capacity in the first ten capacity tests, and the high-rate discharge performance are all significantly reduced because when the pickling density is increased, the lead sulfate layer formed on the surface thickens, and the lead sulfate on the surface is difficult to be completely decomposed and converted into lead dioxide during the battery formation process, resulting in a decrease in the battery capacity. The first capacity of the lead-acid battery manufactured in Comparative Example 11, the highest capacity in the first ten capacity tests, and the high-rate discharge performance are all significantly reduced, and the highest capacity in the first ten capacity tests does not reach the standard requirement because too high a drying temperature leads to the formation of a dense layer on the plate surface, hindering the uniform penetration of sulfuric acid during subsequent battery formation, resulting in incomplete formation, reduced utilization rate of the active material, and a decrease in the battery capacity; at the same time, because nano-silica is added to the lead paste, the water content of the manufactured green grid (wet state) during paste extrusion is about 15 wt.%, and too fast water loss during one-time drying may also lead to deterioration of nano-silica dispersion, formation of agglomerates, destruction of the pore structure of the grid, and reduction of its effect of improving the battery performance.

Claims

1. A method for manufacturing a positive plate electrode, characterized in that, It includes the following steps: S1 Preparation of lead paste: The lead paste is made from the following raw materials in parts by weight: 100 parts of lead powder, 4 - 5 parts of strongly acidic styrene-based cation exchange resin, 0.5 - 1 part of nano-silica, and 9.3 - 10.5 parts of deionized water; The preparation method of the lead paste is as follows: Add the strongly acidic styrene-based cation exchange resin, nano-silica, and 50 parts of lead powder into a paste mixer and conduct the first-stage stirring; Then add the remaining 50 parts of lead powder and conduct the second-stage stirring; Then pour the deionized water into the paste mixer and conduct the third-stage stirring while pouring water, and the stirring speeds of the three stages gradually increase, thus obtaining a lead paste with a bulk density of 4.8 - 5.1 g / cm 3 ³; S2 Acid pickling: Squeeze the lead paste into the tubular grid, install the bottom seal, and pickle it in sulfuric acid electrolyte with a density of 1.6 - 1.65 g / cm 3 ; S3 Drying: After pickling, it is sent into a drying kiln for drying. The humidity in the first stage of drying is 60 - 75%RH, the temperature is 50 - 60°C, and the time is 6 - 8h; the humidity in the second stage of drying is ≤20%RH, the temperature is 70 - 80°C, and the time is 16 - 18h, thus obtaining the positive grid plate.

2. The manufacturing method of the positive grid plate according to claim 1, characterized in that, In step S1, the strongly acidic styrene-based cation exchange resin is the 001X7H type strongly acidic styrene-based cation exchange resin.

3. The manufacturing method of the positive active plate according to claim 1, characterized in that, In step S1, the particle size of the strongly acidic styrene-based cation exchange resin is 0.3 - 0.6mm.

4. The manufacturing method of the positive grid plate according to claim 1, characterized in that, In step S1, the rotation speed of stirring in the first stage is 15 - 20rpm, the rotation speed of stirring in the second stage is 30 - 40rpm, and the rotation speed of stirring in the third stage is 60 - 80rpm.

5. The manufacturing method of the positive active material plate according to claim 4, characterized in that, The stirring time in the first stage is 1 - 1.5min, the stirring time in the second stage is 1 - 1.5min, the time for deionized water to be poured in is 3 - 5min, and the stirring time in the third stage is 5 - 8min.

6. The manufacturing method of the positive grid plate according to claim 5, characterized in that, In step S1, the total pasting time is 7 - 11min.

7. The manufacturing method of the positive active material plate according to claim 1, characterized in that, In step S2, the pickling time is 3 - 5s.

8. Positive raw plate, characterized in that, It is obtained by the manufacturing method of the positive grid plate according to any one of claims 1 - 7.

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