High-temperature-resistant maintenance-free lead-acid storage battery for starting

Abstract

The invention discloses a high-temperature-resistant maintenance-free lead-acid storage battery for starting. The lead-acid storage battery comprises a positive plate, a negative plate, a partition plate, electrolyte and a storage battery tank, the positive plate comprises a positive grid filled with positive lead plaster; the negative plate comprises a negative plate grid filled with negative lead plaster; the negative electrode lead paste is prepared by curing lead powder, a condensation polymer of beta-naphthol sulfonic acid and formaldehyde, lignin, barium sulfate, acetylene black, short fibers, a sulfuric acid aqueous solution and deionized water according to a ratio. The condensation polymer of beta-naphthol sulfonic acid and formaldehyde added in the negative electrode lead paste has low solubility in an electrolyte and strong oxidation resistance, reduces the volume of lead sulfate crystals generated by discharge, increases the porosity of a negative electrode active substance, inhibits the formation of large-particle metal lead in the charging process, delays the shrinkage of the negative electrode active substance, and improves the charging efficiency. Meanwhile, the hydrogen evolution overpotential is improved, and the water loss of the storage battery is inhibited.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of storage batteries, and relates to a high-temperature-resistant maintenance-free starting lead-acid storage battery. BACKGROUND

[0002] The storage battery is an important component of a vehicle, and mainly provides electric energy for starting, ignition and lighting of the vehicle. In recent years, in the tropical regions such as southern China and the Middle East, the liquid-rich maintenance-free storage battery used appears to have the adverse phenomena of liquid deficiency, positive grid corrosion and negative active material "shrinkage", and finally leads to a shorter service life of the storage battery and an increased replacement frequency, which causes great inconvenience for the use of the vehicle.

[0003] In the prior art, the sodium lignosulfonate and humic acid added in the negative lead paste of the starting lead-acid storage battery can completely meet the use requirements of the storage battery under normal conditions. However, due to the high solubility of the sodium lignosulfonate in the electrolyte, the sodium lignosulfonate is easily oxidized at high temperatures and loses effectiveness, which reduces the hydrogen evolution overpotential of the negative electrode, increases the water loss of the storage battery and causes the negative active material to "shrink". On the other hand, the high content of iron ions in the humic acid increases the self-discharge and water loss of the storage battery at high temperatures. The performance deficiencies of the two materials ultimately lead to a shortened service life of the storage battery under high temperature conditions.

[0004] In the prior art, the positive and negative grid plates of the storage battery are formed by the expanded grid or casting process, and both have certain technical defects. Since the expanded grid has no frame and the expansion process inevitably causes crack damage to the ribs, the corrosion resistance of the positive grid plate is reduced at high temperatures, and the corrosion of the positive grid plate is accelerated. The grid of the negative plate formed by the expanded grid has a large grid, so that the negative active material is quickly separated from the grid after "shrinkage", the internal resistance of the storage battery is increased, and the charge and discharge capacity is reduced. The shrinkage hole generated in the forming process of the cast grid becomes the starting point of the oxidation and corrosion of the positive grid, and the ribs around the hole are corroded and broken in advance. In addition, the cast grid also has the disadvantages of large material consumption and low production efficiency. The storage batteries made by the expanded grid and the cast grid both have the problem of a shortened service life under high temperature conditions.

[0005] Therefore, how to solve the problem of the shortened service life of the lead-acid battery under high temperature conditions has become a technical problem to be solved. SUMMARY

[0006] The application aims to provide a high-temperature-resistant maintenance-free starting lead-acid storage battery to solve the problem of the shortened service life of the storage battery caused by the shrinkage of the negative active material and other adverse phenomena in the prior art.

[0007] The technical scheme adopted by the present application is: the high-temperature-resistant maintenance-free starting lead-acid storage battery comprises positive plates, negative plates, separators, electrolyte and a storage battery tank; the positive plate comprises a positive plate grid filled with positive lead paste; the negative plate comprises a negative plate grid filled with negative lead paste; the negative lead paste is prepared by mixing lead powder, a condensate of beta-naphthol sulfonic acid and formaldehyde, lignin, barium sulfate, acetylene black, short fibers, sulfuric acid solution and deionized water in a certain proportion and then solidifying.

[0008] The present application is also characterized in that, Further, the preparation method of the condensate of beta-naphthol sulfonic acid and formaldehyde comprises the following steps: Step 1.1: beta-naphthol is added to a reactor, heated to 135-140 DEG C to completely melt the beta-naphthol, and the temperature is kept at 135-140 DEG C; Step 1.2: under the condition of continuous stirring, 98% concentrated sulfuric acid is added dropwise, and after adding, the sulfonation is continued at 135-140 DEG C for 4-5 hours; Step 1.3: after the sulfonation is completed, the temperature is lowered to 90 DEG C, and under the condition of continuous stirring, distilled water and 98% concentrated sulfuric acid are added dropwise, the temperature is kept at 85-90 DEG C, 37% formaldehyde aqueous solution is added dropwise, and the stirring is continued for 4-5 hours; Step 1.4: under the condition of stirring, 10% NaOH aqueous solution is added dropwise to adjust the pH to 7±1, and then cooled to room temperature to obtain the condensate of beta-naphthol sulfonic acid and formaldehyde.

[0009] The volume ratio of the distilled water, concentrated sulfuric acid and formaldehyde aqueous solution in step 1.3 is 2:1:8; The ratio of the beta-naphthol in step 1.1 to the formaldehyde aqueous solution in step 1.3 is 144g; 80mL; The volume ratio of the concentrated sulfuric acid in step 1.2 to the formaldehyde aqueous solution in step 1.3 is 27:40.

[0010] Further, the positive lead paste comprises the following components in mass fraction: lead powder 100 parts, positive additives 1.0-1.3 parts, sulfuric acid solution with a density of 1.400g / mL 10 parts, and deionized water 8-10 parts.

[0011] Further, the negative lead paste comprises the following components in mass fraction: lead powder 100 parts, condensate of beta-naphthol sulfonic acid and formaldehyde 0.20-0.25 parts, lignin 0.3-0.5 parts, barium sulfate 0.7 parts, acetylene black 0.25 parts, short fibers 0.06 parts, sulfuric acid solution with a density of 1.400g / mL 8.5 parts, and deionized water 8-10 parts.

[0012] Further, the preparation method of the negative lead paste comprises the following steps: Step 2.1: ingredients are prepared according to mass fraction: lead powder 100 parts, β-naphthol sulfonic acid and formaldehyde condensate 0.20~0.25 parts, lignin 0.3~0.5 parts, barium sulfate 0.7 parts, acetylene black 0.25 parts, short fibers 0.06 parts, 8.5 parts of sulfuric acid aqueous solution with a density of 1.400g / mL, 8~10 parts of deionized water; Step 2.2: β-naphthol sulfonic acid and formaldehyde condensate are dissolved in deionized water; Step 2.3: lead powder, lignin, barium sulfate, acetylene black, and short fibers are added to the paster, and dry stirring is mixed for 1~2min; Step 2.4: deionized water with β-naphthol sulfonic acid and formaldehyde condensate dissolved is added, and stirring is performed for 4~6min; Step 2.5: under the condition of continuous stirring, sulfuric acid aqueous solution is slowly added, stirring is performed for 8~10min, and water cooling and air cooling measures are adopted to control the temperature of the lead paste at 55~60℃; Step 2.6: water cooling and air cooling measures are continued to cool, and when the temperature of the lead paste is lower than 45℃, the paster is ended.

[0013] Further, the positive plate grid and the negative plate grid are both made by punching net process, and the positive plate grid and the negative plate grid both include a tab, an upper frame, a left frame, a longitudinal rib, a lower frame, a horizontal rib and a right frame; the horizontal rib and the longitudinal rib form the grid of the plate grid, and in each grid of the plate grid, the horizontal rib has a spacing of 5~6mm, the maximum spacing of the longitudinal rib is 12mm, and the minimum spacing of the longitudinal rib is 2mm.

[0014] Further, the material of the positive plate grid is a first lead-calcium-tin-aluminum alloy, and the first lead-calcium-tin-aluminum alloy is composed of the following components in percentage by mass: calcium 0.06%~0.08%, tin 1.4%~1.5%, aluminum 0.008%~0.016%, and the rest is lead. Further, the material of the negative plate grid is a second lead-calcium-tin-aluminum alloy, and the second lead-calcium-tin-aluminum alloy is composed of the following components in percentage by mass: calcium 0.10%~0.12%, tin 0.1%~0.4%, aluminum 0.008%~0.016%, and the rest is lead.

[0015] Further, the thickness of the positive plate grid is 0.95~1.15mm, and the thickness of the negative plate grid is 0.70~0.85mm.

[0016] The beneficial effects of the present application are: The high-temperature resistant, maintenance-free lead-acid starting battery of this invention uses a condensation polymer of β-naphthol sulfonic acid and formaldehyde, synthesized under high temperature and strong oxidation conditions, added to the negative electrode lead paste. This polymer has low solubility in the electrolyte and strong oxidation resistance. The -OH and -SO3H groups on its surface can be adsorbed onto the surface of the negative electrode active material, reducing the surface tension of the negative electrode active material, decreasing the volume of lead sulfate crystals generated during discharge, increasing the porosity of the negative electrode active material, and inhibiting the formation of large metallic lead particles during charging, thereby delaying the "shrinkage" of the negative electrode active material. Simultaneously, it increases the hydrogen evolution overpotential and inhibits water loss in the battery. However, because the condensation polymer of β-naphthol sulfonic acid and formaldehyde has a strong adsorption effect on lead sulfate, excessive addition will reduce the battery's charge acceptance performance. Lignin is extracted from a byproduct of wood processing. It has low metal impurity content, is insoluble in water and sulfuric acid electrolyte, and can persist in the negative electrode active material for a long time. Lignin contains certain -OH and -COOH groups, which can contribute to the expansion of negative electrode active materials, but its activity is relatively low and the battery capacity is relatively low. When β-naphthol sulfonic acid and formaldehyde condensate are mixed with lignin in an optimal ratio, their respective advantages are brought into play and their shortcomings are compensated for, thereby inhibiting the "shrinkage" of negative electrode active materials and water loss in the battery, and improving the high-temperature cycle durability of the battery.

[0017] This invention relates to a high-temperature resistant, maintenance-free lead-acid starting battery, employing a grid-forming process for the negative electrode grid. For the negative electrode grid, smaller spacing between the transverse and longitudinal ribs in each grid results in stronger conductivity and greater material usage; conversely, larger spacing results in weaker conductivity and less material usage. Considering both material usage and the high-temperature cycle durability of the flooded maintenance-free starting battery, the preferred transverse rib spacing is 5-6 mm, the maximum longitudinal rib spacing is 12 mm, and the minimum longitudinal rib spacing is 2 mm. This size overcomes the problem of the large grid size in expanded-grid negative electrode grids, which makes the "shrinking" negative electrode active material easily separate from the grid, leading to reduced grid conductivity. This improves the high-temperature cycle durability of the battery and reduces material usage compared to negative electrode grids formed by casting.

[0018] This invention relates to a high-temperature resistant, maintenance-free lead-acid starting battery. The positive electrode grid is manufactured using a punching process, where a lead strip of the appropriate thickness is first formed through seven stages of cold rolling, followed by continuous punching. This process reduces the grain size of the lead alloy, increases crystal density, and solves the defects of intergranular cracks in cast grids and cracks in the ribs of expanded grid grids. It also improves the grid's corrosion resistance under high-temperature conditions, enhances the battery's high-temperature cycle durability, and simultaneously reduces material usage. Attached Figure Description

[0019] Figure 1This is a comparison graph of the voltage of the battery during the high-temperature cycle durability test of Embodiment 1 and Comparative Examples 1-4 of the present invention, when the battery is discharged at a constant current of 475A for 30s.

[0020] Figure 2 This is a schematic diagram of the external structure of the continuous grid positive or negative electrode grid of the present invention.

[0021] In the diagram, 1. tab; 2. top border; 3. left border; 4. vertical rib; 5. bottom border; 6. horizontal rib; 7. right border. Detailed Implementation

[0022] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] Example 1 This invention relates to a high-temperature resistant, maintenance-free lead-acid starting battery, comprising a positive plate, a negative plate, a separator, an electrolyte, and a battery case. The positive plate includes a positive plate grid and a positive active material. The positive active material is formed by coating a positive lead paste, prepared by mixing lead powder, positive additives, sulfuric acid aqueous solution, and deionized water in a specific ratio, onto the positive plate grid, followed by curing and formation. The negative plate includes a negative plate grid and a negative active material. The negative active material is formed by coating a negative lead paste, prepared by mixing lead powder, a condensation polymer of β-naphthol sulfonic acid and formaldehyde, lignin, barium sulfate, acetylene black, short fibers, sulfuric acid aqueous solution, and deionized water in a specific ratio, onto the negative plate grid, followed by curing and formation.

[0024] The preferred method for preparing the condensation polymer of β-naphthol sulfonic acid and formaldehyde includes the following steps: Step 1-1: Add 144g of β-naphthol to the reactor, heat to 135℃ to completely melt the β-naphthol, and maintain the temperature at 135~140℃.

[0025] Steps 1-2: Under continuous stirring, add 54 ml of 98% concentrated sulfuric acid dropwise, and continue sulfonation at 135~140℃ for 5 hours after the addition is complete.

[0026] Steps 1-3: Cool down to 90℃, add 20ml of distilled water and 10ml of 98% concentrated sulfuric acid dropwise while stirring continuously; maintain the temperature at 85~90℃, add 80ml of 37% formaldehyde aqueous solution dropwise, and stir continuously for 5 hours.

[0027] Steps 1-4: While stirring, add 10% NaOH aqueous solution dropwise to adjust the pH to about 7, and cool to room temperature.

[0028] The preferred mass ratio of negative electrode lead paste material is as follows: 100 kg lead powder, 0.20 kg condensate of β-naphthol sulfonic acid and formaldehyde, 0.40 kg lignin, 0.7 kg barium sulfate, 0.25 kg acetylene black, 0.06 kg short fiber, 8.5 kg sulfuric acid aqueous solution with a density of 1.400 (g / ml), and 8-10 kg deionized water.

[0029] The preferred method for preparing negative electrode lead paste includes the following steps: Step 2-1: Prepare materials according to the preferred mass ratio of negative electrode lead paste; Step 2-2: Dissolve the condensation product of β-naphthol sulfonic acid and formaldehyde in deionized water; Steps 2-3: Add lead powder, lignin, barium sulfate, acetylene black, and short fibers to the paste mixer and dry mix for 1 minute; Steps 2-4: Add deionized water containing the condensation polymer of β-naphthol sulfonic acid and formaldehyde, and stir for 4 minutes; Steps 2-5: While stirring continuously, slowly add sulfuric acid aqueous solution, stir for 8 minutes, and use water cooling and air cooling measures to control the temperature of lead paste at 55~60℃; Steps 2-6: Continue to use water cooling and air cooling measures to cool the lead paste. When the temperature of the lead paste is below 45℃, the paste mixing process is completed.

[0030] Both the preferred positive and negative electrode grids are manufactured using a stamping process. Each grid includes tabs, an upper frame, a left frame, longitudinal ribs, a lower frame, transverse ribs, and a right frame. The transverse and longitudinal ribs form the grid mesh. Within each grid mesh, the transverse rib spacing is 6mm, the maximum longitudinal rib spacing is 12mm, and the minimum longitudinal rib spacing is 2mm.

[0031] The preferred thickness of the positive electrode grid is 1.05 mm, and the thickness of the negative electrode grid is 0.75 mm.

[0032] The preferred positive electrode grid material is a first lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.06%~0.08%, tin 1.4%~1.5%, aluminum 0.008%~0.016%, and the remainder is lead.

[0033] The preferred negative electrode grid material is a second lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.10%~0.12%, tin 0.1%~0.4%, aluminum 0.008%~0.016%, and the remainder is lead.

[0034] Comparative Example 1 A flooded maintenance-free starting battery includes positive plates, negative plates, separators, electrolyte, and a battery case. The positive plate consists of a positive grid and positive active material. The positive active material is formed by coating a positive lead paste (made from lead powder, positive additives, sulfuric acid aqueous solution, and deionized water in a specific ratio) onto the positive grid, followed by curing and formation. The negative plate consists of a negative grid and negative active material. The negative active material is formed by coating a negative lead paste (made from lead powder, β-naphthol sulfonic acid and formaldehyde condensate, lignin, barium sulfate, acetylene black, short fibers, sulfuric acid aqueous solution, and deionized water in a specific ratio) onto the negative grid, followed by curing and formation.

[0035] The preferred method for preparing the condensation polymer of β-naphthol sulfonic acid and formaldehyde includes the following steps: Step 1-1: Add 144g of β-naphthol to the reactor, heat to 135℃ to completely melt the β-naphthol, and maintain the temperature at 135~140℃.

[0036] Steps 1-2: Under continuous stirring, add 54 ml of 98% concentrated sulfuric acid dropwise, and continue sulfonation at 135~140℃ for 5 hours after the addition is complete.

[0037] Steps 1-3: Cool to 90℃, add 20ml of distilled water dropwise while continuously stirring, and add 10ml of 98% concentrated sulfuric acid dropwise. Maintain the temperature at 85~90℃, add 80ml of 37% formaldehyde aqueous solution dropwise, and continue stirring for 5 hours.

[0038] Steps 1-4: While stirring, add 10% NaOH aqueous solution dropwise to adjust the pH to about 7, and cool to room temperature.

[0039] The preferred mass ratio of negative electrode lead paste material is as follows: 100 kg lead powder, 0.20 kg condensate of β-naphthol sulfonic acid and formaldehyde, 0.40 kg lignin, 0.7 kg barium sulfate, 0.25 kg acetylene black, 0.06 kg short fiber, 8.5 kg sulfuric acid aqueous solution with a density of 1.400 (g / ml), and 8-10 kg deionized water.

[0040] The preferred method for preparing negative electrode lead paste includes the following steps: Step 2-1: Prepare materials according to the preferred mass ratio of negative electrode lead paste; Step 2-2: Dissolve the condensation product of β-naphthol sulfonic acid and formaldehyde in deionized water; Steps 2-3: Add lead powder, lignin, barium sulfate, acetylene black, and short fibers to the paste mixer and dry mix for 1 minute; Steps 2-4: Add deionized water containing the condensation polymer of β-naphthol sulfonic acid and formaldehyde, and stir for 4 minutes; Steps 2-5: While stirring continuously, slowly add sulfuric acid aqueous solution, stir for 8 minutes, and use water cooling and air cooling measures to control the temperature of lead paste at 55~60℃; Steps 2-6: Continue to use water cooling and air cooling measures to cool the lead paste. When the temperature of the lead paste is below 45℃, the paste mixing process is completed.

[0041] Both the positive and negative electrode grids are manufactured using a stamping process. Each grid includes tabs, a top frame, a left frame, longitudinal ribs, a bottom frame, transverse ribs, and a right frame. The transverse and longitudinal ribs form the grid mesh. Within each grid mesh, the transverse rib spacing is 7mm, the maximum longitudinal rib spacing is 12mm, and the minimum longitudinal rib spacing is 2mm.

[0042] The preferred thickness of the positive electrode grid is 1.05 mm, and the thickness of the negative electrode grid is 0.75 mm.

[0043] The preferred positive electrode grid material is a first lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.06%~0.08%, tin 1.4%~1.5%, aluminum 0.008%~0.016%, and the remainder is lead.

[0044] The preferred negative electrode grid material is a second lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.10%~0.12%, tin 0.1%~0.4%, aluminum 0.008%~0.016%, and the remainder is lead.

[0045] Comparative Example 2 A conventional flooded maintenance-free starting battery includes positive plates, negative plates, separators, electrolyte, and a battery case. The positive plate consists of a positive grid and positive active material. The positive active material is formed by coating a positive lead paste (made from lead powder, positive additives, sulfuric acid solution, and deionized iron in a specific ratio) onto the positive grid, followed by curing and formation. The negative plate consists of a negative grid and negative active material. The negative active material is formed by coating a negative lead paste (made from lead powder, humic acid, sodium lignosulfonate, barium sulfate, acetylene black, short fibers, sulfuric acid solution, and deionized iron in a specific ratio) onto the positive grid, followed by curing and formation.

[0046] The mass ratio of the negative electrode lead paste material is as follows: 100 kg lead powder, 0.30 kg humic acid, 0.15 kg sodium lignosulfonate, 0.7 kg barium sulfate, 0.25 kg acetylene black, 0.06 kg short fiber, 8.5 kg sulfuric acid aqueous solution with a density of 1.400 (g / ml), and 8-10 kg deionized water.

[0047] The preparation method of negative electrode lead paste includes the following steps: Step 2-1: Prepare materials according to the mass ratio of negative electrode lead paste; Step 2-2: Add lead powder, humic acid, sodium lignosulfonate, barium sulfate, acetylene black, and short fibers to the paste mixer and dry mix for 1 minute; Steps 2-3: Add deionized water and stir for 4 minutes; Steps 2-4: While stirring continuously, slowly add sulfuric acid aqueous solution, stir for 8 minutes, and use water cooling and air cooling to control the temperature of lead paste at 45~60℃.

[0048] Steps 2-5: Continue to use water cooling and air cooling measures to cool the lead paste. When the temperature of the lead paste is below 45℃, stop the paste mixing process.

[0049] Both the positive and negative grids are manufactured using a continuous mesh expansion process. The lead strip thickness of the positive grid is 0.90 mm, and the lead strip thickness of the negative grid is 0.75 mm.

[0050] The positive electrode grid material is a first lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.06%~0.08%, tin 1.4%~1.5%, aluminum 0.008%~0.016%, and the remainder is lead.

[0051] The negative electrode grid material is a second lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.10%~0.12%, tin 0.1%~0.4%, aluminum 0.008%~0.016%, and the remainder is lead.

[0052] Comparative Example 3 A flooded maintenance-free starting battery includes positive plates, negative plates, separators, electrolyte, and a battery case. The positive plate consists of a positive grid and positive active material. The positive active material is formed by coating a positive lead paste (made from lead powder, positive additives, sulfuric acid aqueous solution, and deionized water in a specific ratio) onto the positive grid, followed by curing and formation. The negative plate consists of a negative grid and negative active material. The negative active material is formed by coating a negative lead paste (made from lead powder, β-naphthol sulfonic acid and formaldehyde condensate, lignin, barium sulfate, acetylene black, short fibers, sulfuric acid aqueous solution, and deionized water in a specific ratio) onto the negative grid, followed by curing and formation.

[0053] The preferred method for preparing the condensation polymer of β-naphthol sulfonic acid and formaldehyde includes the following steps: Step 1-1: Add 144g of β-naphthol to the reactor, heat to 135℃ to completely melt the β-naphthol, and maintain the temperature at 135~140℃.

[0054] Steps 1-2: Under continuous stirring, add 54 ml of 98% concentrated sulfuric acid dropwise, and continue sulfonation at 135~140℃ for 5 hours after the addition is complete.

[0055] Steps 1-3: Cool to 90℃, add 20ml of distilled water dropwise while continuously stirring, and add 10ml of 98% concentrated sulfuric acid dropwise. Maintain the temperature at 85~90℃, add 80ml of 37% formaldehyde aqueous solution dropwise, and continue stirring for 5 hours.

[0056] Steps 1-4: While stirring, add 10% NaOH aqueous solution dropwise to adjust the pH to about 7, and cool to room temperature.

[0057] The preferred mass ratio of negative electrode lead paste material is as follows: 100 kg lead powder, 0.20 kg condensate of β-naphthol sulfonic acid and formaldehyde, 0.40 kg lignin, 0.7 kg barium sulfate, 0.25 kg acetylene black, 0.06 kg short fiber, 8.5 kg sulfuric acid aqueous solution with a density of 1.400 (g / ml), and 8-10 kg deionized water.

[0058] The preferred method for preparing negative electrode lead paste includes the following steps: Step 2-1: Prepare materials according to the preferred mass ratio of negative electrode lead paste; Step 2-2: Dissolve the condensation product of β-naphthol sulfonic acid and formaldehyde in deionized water; Steps 2-3: Add lead powder, lignin, barium sulfate, acetylene black, and short fibers to the paste mixer and dry mix for 1 minute; Steps 2-4: Add deionized water containing the condensation polymer of β-naphthol sulfonic acid and formaldehyde, and stir for 4 minutes; Steps 2-5: While stirring continuously, slowly add sulfuric acid aqueous solution, stir for 8 minutes, and use water cooling and air cooling measures to control the temperature of lead paste at 55~60℃; Steps 2-6: Continue to use water cooling and air cooling measures to cool the lead paste. When the temperature of the lead paste is below 45℃, the paste mixing process is completed.

[0059] Both the positive and negative grids are manufactured using a continuous mesh expansion process. The lead strip thickness of the positive grid is 0.90 mm, and the lead strip thickness of the negative grid is 0.75 mm.

[0060] The positive electrode grid material is a first lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.06%~0.08%, tin 1.4%~1.5%, aluminum 0.008%~0.016%, and the remainder is lead.

[0061] The negative electrode grid material is a second lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.10%~0.12%, tin 0.1%~0.4%, aluminum 0.008%~0.016%, and the remainder is lead.

[0062] Comparative Example 4 A flooded maintenance-free starting battery includes positive plates, negative plates, separators, electrolyte, and a battery case. The positive plate consists of a positive grid and positive active material. The positive active material is formed by coating a positive lead paste (made from lead powder, positive additives, sulfuric acid aqueous solution, and deionized water in a specific ratio) onto the positive grid, followed by curing and formation. The negative plate consists of a negative grid and negative active material. The negative active material is formed by coating a negative lead paste (made from lead powder, β-naphthol sulfonic acid and formaldehyde condensate, lignin, barium sulfate, acetylene black, short fibers, sulfuric acid aqueous solution, and deionized water in a specific ratio) onto the negative grid, followed by curing and formation.

[0063] The preferred method for preparing the condensation polymer of β-naphthol sulfonic acid and formaldehyde includes the following steps: Step 1-1: Add 144g of β-naphthol to the reactor, heat to 135℃ to completely melt the β-naphthol, and maintain the temperature at 135~140℃.

[0064] Steps 1-2: Under continuous stirring, add 54 ml of 98% concentrated sulfuric acid dropwise, and continue sulfonation at 135~140℃ for 5 hours after the addition is complete.

[0065] Steps 1-3: Cool to 90℃, add 20ml of distilled water dropwise while continuously stirring, and add 10ml of 98% concentrated sulfuric acid dropwise. Maintain the temperature at 85~90℃, add 80ml of 37% formaldehyde aqueous solution dropwise, and continue stirring for 5 hours.

[0066] Steps 1-4: While stirring, add 10% NaOH aqueous solution dropwise to adjust the pH to about 7, and cool to room temperature.

[0067] The preferred mass ratio of negative electrode lead paste material is as follows: 100 kg lead powder, 0.20 kg condensate of β-naphthol sulfonic acid and formaldehyde, 0.40 kg lignin, 0.7 kg barium sulfate, 0.25 kg acetylene black, 0.06 kg short fiber, 8.5 kg sulfuric acid aqueous solution with a density of 1.400 (g / ml), and 8-10 kg deionized water.

[0068] The preferred method for preparing negative electrode lead paste includes the following steps: Step 2-1: Prepare materials according to the preferred mass ratio of negative electrode lead paste; Step 2-2: Dissolve the condensation product of β-naphthol sulfonic acid and formaldehyde in deionized water; Steps 2-3: Add lead powder, lignin, barium sulfate, acetylene black, and short fibers to the paste mixer and dry mix for 1 minute; Steps 2-4: Add deionized water containing the condensation polymer of β-naphthol sulfonic acid and formaldehyde, and stir for 4 minutes; Steps 2-5: While stirring continuously, slowly add sulfuric acid aqueous solution, stir for 8 minutes, and use water cooling and air cooling measures to control the temperature of lead paste at 55~60℃; Steps 2-6: Continue to use water cooling and air cooling measures to cool the lead paste. When the temperature of the lead paste is below 45℃, the paste mixing process is completed.

[0069] Both the positive and negative electrode grids are manufactured using a casting process. Each grid includes tabs, a top frame, a left frame, longitudinal ribs, a bottom frame, transverse ribs, and a right frame. The transverse and longitudinal ribs form the grid mesh. Within each grid mesh, the transverse ribs are spaced 6 mm apart, the maximum longitudinal rib spacing is 12 mm, and the minimum longitudinal rib spacing is 2 mm.

[0070] The thickness of the positive electrode grid is 1.5 mm, and the thickness of the positive electrode grid is 1.2 mm.

[0071] The positive electrode grid material is a first lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.06%~0.08%, tin 1.4%~1.5%, aluminum 0.008%~0.016%, and the remainder is lead.

[0072] The negative electrode grid material is a second lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.10%~0.12%, tin 0.1%~0.4%, aluminum 0.008%~0.016%, and the remainder is lead.

[0073] Detection example Examples 1 and Comparative Examples 1-4 were prepared into corresponding 6-QW-60 type battery samples and tested. All sample batteries were identical in technology except for the listed specifications. Tests on the sample batteries included mass, 20-hour rate capacity, low-temperature start-up (-18°C, 475A), charge acceptance, water loss, and high-temperature cycle durability.

[0074] Quality, 20-hour rate capacity, and low-temperature starting performance shall comply with GB / T 43346-2023.

[0075] Charging acceptance performance test method: In a water bath at 25±2℃, the fully charged battery was first discharged for 5 hours at a current of one-tenth of its actual capacity. Then, the battery was placed in a low-temperature chamber at 0±1℃ for 24 hours to freeze. After that, it was continuously charged for 10 minutes at a constant voltage of 14.4±0.1V and a current limit of 80A. The ratio of the charging current at 10 minutes to the current at one-tenth of the actual capacity was recorded.

[0076] The high-temperature water loss performance test method is as follows: After fully charging the battery, weigh it and place it in a water bath at 60±2℃. Charge it continuously at a constant voltage of 14.4V for 504 hours, and weigh it again. Record the ratio of the difference in battery mass before and after charging to its rated capacity, in g / Ah.

[0077] The high-temperature cycling durability test method is as follows: Place the fully charged battery in a water bath at 40±2℃ and perform a charge-discharge cycle as follows: Step 3-1: Charge at a constant voltage of 14.8V with a current limit of 25A for 10 minutes; Step 3-2: Discharge at a constant current of 25A for 4 minutes; Step 3-3: Charge at a constant voltage of 14.8V and a current limit of 25A for 10 minutes; Step 3-4: Repeat step 3-2 to step 3-3 429 times consecutively. Steps 3-5: Discharge at a constant current of 475A for 30s at 40±2℃; If the battery voltage is not lower than 7.2V after discharging for 30 seconds in step 3-5, the test continues from step 3-1; otherwise, the test ends, and the number of charge-discharge cycles completed by the battery is the high-temperature cycle durability.

[0078] The performance test results of the battery samples are shown in Table 1.

[0079] The voltage comparison chart of the battery during high-temperature cycle durability testing, when discharged at a constant current of 475A for 30 seconds, is shown below. Figure 1 .

[0080] Table 1

[0081] Based on the comparison of the above test data, the embodiments of the present invention have the following advantages: 1. In Example 1, the spacing of the transverse ribs of the negative plate grid is 6mm. Compared with Comparative Example 1, which has a spacing of 7mm, the sample battery has little difference in mass, 20h rate capacity, low temperature start-up, charge acceptance, and high temperature water loss performance. The high temperature cycle durability is improved by 16.9%.

[0082] 2. Comparative Example 2 used existing negative electrode additives and existing continuous expanded grid positive and negative electrode grids. Compared with Comparative Example 2, Example 1 showed little difference in sample battery mass, 20-hour rate capacity, low-temperature start-up, and charge acceptance performance, but its high-temperature water loss performance decreased by 42.8%, and its high-temperature cycle durability improved by 198.2%.

[0083] 3. Comparative Example 3 employed preferred negative electrode additives and negative electrode paste preparation techniques, and utilized existing continuous expanded-grid positive and negative electrode grids (with larger grids). Compared to Comparative Example 3, Example 1 showed little difference in sample battery mass, 20-hour rate capacity, low-temperature start-up, charge acceptance, and high-temperature water loss performance, but its high-temperature cycle durability was improved by 96.6%.

[0084] 4. Comparative Example 4 employed optimized negative electrode additives and negative electrode paste preparation techniques, and utilized existing cast positive and negative electrode grids. Compared to Example 1, Comparative Example 4 showed little difference in the 20-hour rate capacity, low-temperature start-up, charge acceptance, and high-temperature water loss performance of the sample battery. However, its high-temperature cycle durability improved by 25.4%, and its mass decreased by 4.2%. The mass reduction of the sample was due to the reduction in the amount of positive and negative electrode grid materials used.

[0085] 5. Comparative Example 3 employed optimized negative electrode additives and negative electrode paste preparation techniques, and utilized existing continuous expanded-grid positive and negative electrode grids; Comparative Example 2 employed existing negative electrode additives and existing continuous expanded-grid positive and negative electrode grids. Compared to Comparative Example 2, Comparative Example 3 showed little difference in sample battery mass, 20-hour rate capacity, low-temperature start-up, and charge acceptance performance, but its high-temperature water loss performance decreased by 41.3%, and its high-temperature cycle durability improved by 51.7%.

Claims

1. A high-temperature resistant, maintenance-free lead-acid starting battery, characterized in that, It includes a positive electrode plate, a negative electrode plate, a separator, an electrolyte, and a battery case; the positive electrode plate includes a positive electrode grid filled with positive electrode lead paste; the negative electrode plate includes a negative electrode grid filled with negative electrode lead paste; the negative electrode lead paste is formed by curing a mixture of lead powder, β-naphthol sulfonic acid and formaldehyde condensate, lignin, barium sulfate, acetylene black, short fibers, sulfuric acid aqueous solution, and deionized water in a certain proportion.

2. The high-temperature resistant, maintenance-free lead-acid starting battery according to claim 1, characterized in that, The preparation method of the condensation polymer of β-naphthol sulfonic acid and formaldehyde includes the following steps: Step 1.1: Add β-naphthol to the reactor, heat to 135~140℃ to completely melt β-naphthol, and maintain the temperature at 135~140℃; Step 1.2: Under continuous stirring, add concentrated sulfuric acid with a mass concentration of 98% dropwise, and continue sulfonation at 135~140℃ for 4~5 hours after the addition is complete; Step 1.3: After sulfonation, when the temperature is reduced to 90°C, distilled water and 98% concentrated sulfuric acid are added dropwise while continuously stirring. The temperature is maintained at 85~90°C. A 37% formaldehyde aqueous solution is added dropwise while continuously stirring for 4~5 hours. Step 1.4: Under stirring, add 10% NaOH aqueous solution to adjust the pH to 7±1, cool to room temperature, and obtain the condensation polymer of β-naphthol sulfonic acid and formaldehyde.

3. The high-temperature resistant, maintenance-free lead-acid starting battery according to claim 2, characterized in that, The volume ratio of distilled water, concentrated sulfuric acid, and formaldehyde aqueous solution in step 1.3 is 2:1:8; The ratio of β-naphthol in step 1.1 to formaldehyde aqueous solution in step 1.3 is 144g: 80mL; The volume ratio of concentrated sulfuric acid in step 1.2 to the formaldehyde aqueous solution in step 1.3 is 27:

40.

4. The high-temperature resistant, maintenance-free lead-acid starting battery according to claim 1, characterized in that, The positive electrode lead paste comprises the following components by mass: 100 parts lead powder, 1.0 to 1.3 parts positive electrode additive, 10 parts sulfuric acid aqueous solution with a density of 1.400 g / mL, and 8 to 10 parts deionized water.

5. The high-temperature resistant, maintenance-free lead-acid starting battery according to claim 1, characterized in that, The negative electrode lead paste comprises the following components by mass: 100 parts lead powder, 0.20-0.25 parts condensate of β-naphthol sulfonic acid and formaldehyde, 0.3-0.5 parts lignin, 0.7 parts barium sulfate, 0.25 parts acetylene black, 0.06 parts short fibers, 8.5 parts sulfuric acid aqueous solution with a density of 1.400 g / mL, and 8-10 parts deionized water.

6. The high-temperature resistant, maintenance-free lead-acid starting battery according to claim 5, characterized in that, The method for preparing the negative electrode lead paste includes the following steps: Step 2.1: Prepare materials according to the following mass proportions: 100 parts lead powder, 0.20~0.25 parts condensate of β-naphthol sulfonic acid and formaldehyde, 0.3~0.5 parts lignin, 0.7 parts barium sulfate, 0.25 parts acetylene black, 0.06 parts short fiber, 8.5 parts sulfuric acid aqueous solution with a density of 1.400 g / mL, and 8~10 parts deionized water; Step 2.2: Dissolve the condensate of β-naphthol sulfonic acid and formaldehyde in deionized water; Step 2.3: Add lead powder, lignin, barium sulfate, acetylene black, and short fibers to the paste mixer and dry mix for 1-2 minutes; Step 2.4: Add deionized water containing the condensate of β-naphthol sulfonic acid and formaldehyde, and stir for 4-6 minutes; Step 2.5: While stirring continuously, slowly add sulfuric acid aqueous solution, stir for 8-10 minutes, and use water cooling and air cooling measures to control the temperature of lead paste at 55-60℃; Step 2.6: Continue to use water cooling and air cooling measures to cool the lead paste. When the temperature of the lead paste is below 45℃, stop the paste mixing process.

7. The high-temperature resistant, maintenance-free lead-acid starting battery according to claim 1, characterized in that, Both the positive and negative electrode grids are manufactured using a stamping process. Both the positive and negative electrode grids include tabs (1), upper frame (2), left frame (3), longitudinal ribs (4), lower frame (5), transverse ribs (6), and right frame (7). The transverse ribs (6) and longitudinal ribs (4) constitute the grid mesh. In each grid mesh, the spacing between the transverse ribs (6) is 5~6mm, the maximum spacing between the longitudinal ribs (4) is 12mm, and the minimum spacing between the longitudinal ribs (4) is 2mm.

8. The high-temperature resistant, maintenance-free lead-acid starting battery according to claim 1, characterized in that, The positive electrode grid material is a first lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.06%~0.08%, tin 1.4%~1.5%, aluminum 0.008%~0.016%, and the remainder is lead; The negative electrode grid material is a second lead-calcium-tin-aluminum alloy, which is composed of the following components by mass percentage: calcium 0.10%~0.12%, tin 0.1%~0.4%, aluminum 0.008%~0.016%, and the remainder is lead.

9. The high-temperature resistant, maintenance-free lead-acid starting battery according to claim 1, characterized in that: The thickness of the positive electrode grid is 0.95~1.15mm, and the thickness of the negative electrode grid is 0.70~0.85mm.

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