Positive electrode lead paste of valve-regulated sealed lead-acid storage battery and preparation method of positive electrode lead paste

Abstract

The invention relates to the technical field of positive lead paste of lead-acid storage batteries, and particularly discloses positive lead paste of a valve-regulated sealed lead-acid storage battery and a preparation method of the positive lead paste. Functional components such as stannous sulfate, antimonous oxide, graphite, a silicon dioxide dispersion liquid and hydroxylamine sulfate are added, the weight ratio of all the components is precisely regulated and controlled, all the additive components have a synergistic effect, graphite constructs a low-resistance conductive network, nano-silicon dioxide inhibits softening of lead plaster, short fibers reinforce structural stability, and hydroxylamine sulfate reduces vulcanization of a polar plate. According to the invention, the core problems of poor low-temperature charge-discharge performance, easy falling of active substances, short cycle life and the like of the valve-regulated sealed lead-acid storage battery in a low-temperature energy storage scene are solved, and meanwhile, the valve-regulated sealed lead-acid storage battery is compatible with the existing industrial production process and has remarkable technical advantages and application value.

Description

Technical Field

[0001] This invention relates to the field of lead-acid battery positive electrode paste technology, and in particular to a valve-regulated sealed lead-acid battery positive electrode paste and its preparation method. Background Technology

[0002] Valve-regulated sealed lead-acid (VRLA) batteries have gained widespread application in renewable energy storage, backup power for communication base stations, emergency power supply for rail transit, and distributed microgrids due to their significant advantages such as compact structure, no electrolyte leakage, easy maintenance, and controllable cost. As the global energy structure transitions towards cleaner and lower-carbon energy, the large-scale development of energy storage systems places higher demands on the performance of VRLA batteries, with long cycle life, high charge-discharge efficiency, and adaptability to harsh operating conditions becoming core technical indicators.

[0003] As the core reaction area for energy conversion in VRLA batteries, the positive electrode paste's formulation and manufacturing process directly determine the battery's active material utilization rate, cycle stability, and lifespan. During battery charge-discharge cycles, lead dioxide undergoes a dynamic process of "formation-dissolution-recrystallization," accompanied by significant volume changes: during discharge, some lead dioxide is reduced to lead sulfate, and the newly formed solid lead sulfate has a 92% larger molar volume than the lead dioxide that participated in the reaction; during charging, the volume changes in the opposite direction, with the electrode volume shrinking proportionally, causing the lead paste to continuously experience volume "pulsations" during cycling. Specifically, during discharge, the electrode thickness increases and the volume of the active material expands, causing the lead paste micropores to be squeezed smaller; during charging, the electrode thickness shrinks and the active material micropores expand accordingly. This periodic volume expansion and contraction gradually weakens the bonding force between active material particles, leading to a looser structure and reduced bonding strength between the active material and the grid. Ultimately, this results in problems such as lead paste softening and shedding, coarse grains, and broken conductive networks, causing rapid capacity decay and shortened cycle life. In addition, the increased viscosity of the electrolyte and the reduced ion migration rate at low temperatures hinder the reaction kinetics of the active materials in the lead paste, resulting in a significant decrease in battery charging and discharging efficiency, and even problems such as incomplete charging and a sharp reduction in discharge capacity, making it difficult to meet the application needs of high-latitude regions and low-temperature energy storage scenarios.

[0004] Therefore, there is an urgent need to develop a positive electrode paste that combines high conductivity, excellent structural stability, and good low-temperature performance to improve the energy storage reliability and service life of VRLA batteries and promote their further application in the field of large-scale energy storage. Summary of the Invention

[0005] To address the problems of poor low-temperature charge-discharge performance and short cycle life in existing lead-acid battery positive electrode pastes, this invention provides a valve-regulated sealed lead-acid battery positive electrode paste and its preparation method. This invention uses stannous sulfate, antimony trioxide, graphite, silica dispersion, and hydroxylamine sulfate as additives in the positive electrode paste, significantly extending battery cycle life and low-temperature charge-discharge performance. This can promote the large-scale application of VRLA batteries for low-temperature energy storage and has broad application prospects.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the embodiments of the present invention is as follows: In a first aspect, the present invention provides a positive electrode paste for a valve-regulated sealed lead-acid battery, comprising, based on the mass of 100% lead powder, the following additive components in mass percentage: antimony trioxide 0.08%~0.1%, stannous sulfate 0.05%~0.08%, graphite 0.2%~0.25%, silica dispersion 0.5%~1.0%, and hydroxylamine sulfate 0.05%~0.1%.

[0007] Compared to existing technologies, the valve-regulated sealed lead-acid battery positive electrode paste provided by this invention uses antimony trioxide, stannous sulfate, graphite, silica dispersion, and hydroxylamine sulfate as additives. Antimony trioxide stabilizes the crystal structure of the active material, inhibits softening of the positive electrode active material, and improves the contact between the active material and the current collector, significantly reducing battery internal resistance and the risk of active material shedding. Graphite itself has excellent conductivity; as a highly conductive component, it can construct a continuous and low-impedance conductive path within the paste, effectively avoiding localized reaction blind zones caused by uneven dispersion of traditional conductive agents. The synergistic effect of antimony trioxide and graphite enhances the conductivity of the paste, ensuring uniform current distribution during charging and discharging, and significantly improving the utilization rate of the active material. Stannous sulfate inhibits the corrosion rate of the positive electrode grid during charge-discharge cycles, reducing the problem of increased interfacial impedance between the grid and the active material. Its excellent conductivity further optimizes the current distribution within the paste, improving the utilization rate of the positive electrode active material. Nano-sized silica particles can act as nucleation inhibitors, promoting the formation of fine crystals with high specific surface area in the active material, while simultaneously synergistically inhibiting lead paste softening with antimony trioxide. Hydroxylamine sulfate can reduce the formation of high-valence lead oxides in the lead paste, preventing the accumulation of inert substances. It can also improve the stability of the active material, reduce plate sulfation, and further enhance battery cycle stability.

[0008] The valve-regulated sealed lead-acid battery positive electrode paste provided by this invention improves the utilization rate of active materials and extends cycle life while taking into account conductivity, structural stability and charging efficiency. It can fully meet the high-performance requirements of VRLA batteries in fields such as renewable energy storage and communication backup power, and can promote the large-scale application of VRLA batteries for low-temperature energy storage, with broad application prospects.

[0009] Furthermore, based on the mass of lead powder as 100%, the positive electrode paste of the valve-regulated sealed lead-acid battery also includes 9%~9.5% dilute sulfuric acid, 12%~13% water, and 0.15%~0.18% short fibers.

[0010] Furthermore, the positive electrode paste of the valve-regulated sealed lead-acid battery comprises the following components in parts by weight: 1000 parts lead powder, 90-95 parts dilute sulfuric acid, 120-130 parts water, 1.5-1.8 parts short fiber, 0.8-1.0 parts antimony trioxide, 0.5-0.8 parts stannous sulfate, 2.0-2.5 parts graphite, 5.0-10 parts silica dispersion, and 0.5-1.0 parts hydroxylamine sulfate.

[0011] Furthermore, the lead powder has an oxidation content of 71%~75% and an apparent density of 1.20 g / cm³. 3 ~1.40g / cm 3 (30 mesh sieve).

[0012] It should be noted that the oxidation amount of lead powder refers to the content of lead monoxide in the lead powder.

[0013] Lead powder with this oxidation level can better convert energy during battery charging and discharging, thus improving the battery's charging and discharging efficiency and resulting in a more stable charging and discharging curve. The lead powder with this oxidation level also has a more uniform particle size, which allows for a more even distribution of active material on the electrode plates during the manufacturing process. This leads to more consistent performance across all cells in the battery pack, ultimately improving the overall performance and lifespan of the battery pack.

[0014] Furthermore, the density of the dilute sulfuric acid at 25°C is 1.400 ± 0.002 g / cm³. 3 .

[0015] Furthermore, the short fibers are polyester fibers with a length of 3mm to 5mm.

[0016] Short fibers can form a three-dimensional support framework inside the lead paste, effectively resisting the stress caused by the volume "pulsation" of the lead paste during charge and discharge cycles, and preventing problems such as loosening and shedding of active materials. This strengthens the structural stability of the electrode plate, ensuring long-term stable operation and extending the battery's lifespan. At the same time, the introduction of short fibers can control the content of free lead in the lead paste, significantly improving the consistency of performance in different areas of the electrode plate, reducing process fluctuations during manufacturing, and making electrode plate production more stable and controllable. In addition, short fibers can also optimize the microporous structure of the lead paste and the electrolyte wetting environment, improving the battery's charge acceptance to a certain extent and further enhancing battery efficiency.

[0017] Furthermore, the mass concentration of the silica dispersion is 15%~20%, and the silica particle size is 10nm~12nm.

[0018] Silica nanoparticles can act as crystal nucleation inhibitors, promoting the formation of fine crystals with high specific surface area in active materials. At the same time, they can also inhibit the softening of positive electrode lead paste and extend battery cycle life.

[0019] Furthermore, the graphite has a particle size of 20 μm to 30 μm.

[0020] The particle size range of 20μm to 30μm allows graphite to have both good dispersibility and dense packing in lead paste. This avoids the problem of easy agglomeration of fine-particle graphite and prevents conductive gaps caused by coarse-particle graphite, thereby building a continuous and stable conductive framework in the lead paste and effectively eliminating local reaction blind zones.

[0021] Secondly, this aspect provides a method for preparing the positive electrode lead paste for the valve-regulated sealed lead-acid battery mentioned above, including the following steps: Weigh each raw material according to the formula of the positive electrode paste for valve-regulated sealed lead-acid batteries. Mix the weighed lead powder, short fiber, antimony trioxide, stannous sulfate, graphite and hydroxylamine sulfate evenly, add water, and obtain a mixed slurry. Spray silica dispersion into the mixed slurry, mix evenly, and then add dilute sulfuric acid to obtain valve-regulated sealed lead-acid battery positive electrode paste.

[0022] The present invention provides a method for preparing positive electrode lead paste for valve-regulated sealed lead-acid batteries. First, lead powder, short fibers, antimony trioxide, stannous sulfate, graphite, and hydroxylamine sulfate are mixed with water to form a uniform slurry. Then, a silica dispersion is added by spraying, allowing nano-silica particles to uniformly cover the surface and internal micropores of the slurry, fully utilizing its crystal nucleation inhibitor effect. Dilute sulfuric acid is added last to effectively control the neutralization reaction rate between lead powder and sulfuric acid, preventing localized overheating that could lead to paste drying or component failure.

[0023] The method for preparing positive electrode lead paste for valve-regulated sealed lead-acid batteries provided by this invention is simple in process, and ensures the stability of lead paste performance while taking into account the convenience of production, making it easy to realize the large-scale production of positive electrode lead paste.

[0024] Furthermore, the apparent density of the positive electrode paste of the valve-regulated sealed lead-acid battery is 4.20 g / cm³. 3 ~4.30g / cm 3 .

[0025] The positive electrode lead paste provided by this invention uses lead powder as the core active material and adds functional components such as stannous sulfate, antimony trioxide, graphite, silica dispersion and hydroxylamine sulfate. By precisely controlling the weight ratio of each component, it specifically solves the core pain points of valve-regulated sealed lead-acid batteries in low-temperature energy storage scenarios, such as poor low-temperature charge and discharge performance, easy shedding of active materials and short cycle life. At the same time, it is compatible with existing industrial production processes and has significant technical advantages and application value. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0027] To better illustrate the present invention, further examples are provided below.

[0028] The lead powder used in the following examples has an oxidation content of 71%~75% and an apparent density of 1.20 g / cm³. 3 ~1.40g / cm 3 (30-mesh sieve); The density of dilute sulfuric acid at 25℃ is 1.400±0.002 g / cm³. 3 The short fibers are polyester fibers with a length of 3mm to 5mm; the mass concentration of the silica dispersion is 15%, and the silica particle size is 10nm to 12nm; the graphite particle size is 20μm to 30μm.

[0029] Example 1 This embodiment provides a positive electrode paste for a valve-regulated sealed lead-acid battery, with the following specific composition: 1000 kg lead powder, 93.7 kg dilute sulfuric acid, 125 kg purified water, 1.5 kg short fiber, 0.8 kg antimony trioxide, 0.5 kg stannous sulfate, 2.0 kg graphite, 6.0 kg silica dispersion and 0.5 kg hydroxylamine sulfate.

[0030] The preparation method of the above-mentioned valve-regulated sealed lead-acid battery positive electrode lead paste includes the following steps: Weigh each component according to the above proportions, add the weighed lead powder to the automatic paste mixer, then add short fiber, antimony trioxide, stannous sulfate, graphite and hydroxylamine sulfate, dry stir for 6 minutes, add purified water while stirring, add all the purified water in 2 minutes, wet stir for 2 minutes to obtain the mixed slurry. The weighed silica dispersion was sprayed onto the surface of the mixed slurry while stirring. All the silica dispersion was added over 3 minutes, followed by wet stirring for 3 minutes. Cooling water was then turned on, and dilute sulfuric acid was added while stirring continuously. All the dilute sulfuric acid was added over 18 minutes. After adding acid for 5 minutes, the air-cooling system was turned on to ensure the lead paste temperature did not exceed 60°C during the mixing process. After adding acid, stirring continued for 14 minutes. When the lead paste temperature was below 45°C, the apparent density was measured. The apparent density of the lead paste was required to be 4.20 g / cm³. 3 ~4.30g / cm 3 , to obtain the positive electrode lead paste for valve-regulated sealed lead-acid batteries.

[0031] The valve-regulated sealed lead-acid battery positive electrode paste prepared above was used to assemble 6-CNF-200 (12V 200Ah) valve-regulated sealed lead-acid batteries for energy storage through conventional processes in the field, including coating, curing and drying, separating, wrapping, electrode group welding, intermediate terminal bridging, and shell sealing. After the acid injection and formation were completed, capacity, low-temperature capacity, charging efficiency, and 100% DOD cycle tests were conducted in accordance with the GB / T 22473.1-2021 standard for energy storage lead-acid batteries.

[0032] The specific testing method is as follows: 1. 10hr capacity testing method: A fully charged lead-acid battery is left to stand at 25±5℃ for 24 hours. The battery is then discharged at a constant current of 20A to 10.8V, and the total discharge time is recorded. The actual capacity of this battery after 10 hours must meet the requirement of not less than 200Ah of the rated capacity at or before the third capacity test.

[0033] 2. Low temperature capacity (-10℃) The fully charged battery was placed in an environment of -10±2℃ for 20 hours, then discharged at a constant current of 20A to 10.8V, and the total discharge time was recorded. The low-temperature capacity of the battery must meet the requirement of not being lower than the rated capacity of 150.0Ah on or before the third capacity test.

[0034] 3. Charging efficiency 3.1 Select batteries that pass the 10-hour capacity test and record their actual discharge capacity value, denoted as C. e Then the battery is fully charged.

[0035] 3.2 Then, discharge the battery at a current of 20A until the discharged charge reaches the actual capacity C. e Discharge was stopped when the battery reached 10% capacity. The battery was then fully charged, and the charge capacity was recorded as C. a1 .

[0036] 3.3 Repeat steps 3.2, performing two tests: the first discharge until C is released. e Stop charging when the charge reaches 25%, and record the charging capacity after full charging, denoted as C. a2 The second discharge until C is released. e Stop charging when the charge reaches 50%, and record the charging capacity after full charging, denoted as C. a3 , 3.4 Calculate the battery's state of charge (SOC) at 90% (corresponding to a discharge rate of 10%) using the following formulas. e ), 75% SOC (corresponding to the release of 25% C e ), 50% SOC (corresponding to the release of 50% C e The charging efficiency under three charging conditions is denoted as η.

[0037] η=C ex / C ax ×100% In the formula: η is the charging efficiency; C ax The charging capacity C corresponding to 90% SOC, 75% SOC, and 50% SOC is given. a1 C a2 C a3 The unit is Ah; C ex The discharge capacity C corresponding to 90% SOC, 75% SOC, and 50% SOC is given. e1 C e2 C e3 The unit is Ah.

[0038] 4. 100% DOD lifecycle The 100% DOD cycle test procedure is as follows: (1) Select a battery that has passed the capacity test and place it in a constant temperature environment of 25±2℃. Discharge it with a constant current of 20A until the battery voltage drops to 10.8V; (2) After the discharge is completed, charge the battery in a constant voltage mode of 14.1V and a current limit of 30A. The charging time is set to 16h; (3) Cycle according to the above two steps. When the discharge capacity is lower than 160Ah, the cycle is terminated. A total of 365 cycles were completed in this test. The specific results are shown in Table 1.

[0039] Table 1

[0040] A 6-CNF-200 (12V 200Ah) battery was made using conventional positive electrode lead paste (1000kg lead powder, 130kg purified water, 93kg dilute sulfuric acid, 0.6kg short fiber) and negative electrode lead paste (1000kg lead powder, 130kg purified water, 72kg dilute sulfuric acid, 0.6kg short fiber, 1.8kg acetylene black, 12kg barium sulfate, 2kg lignin) according to the same process described above. The battery was tested for various indicators using the same method as described above, and the results are shown in Table 2.

[0041] Table 2

[0042] The results show that the valve-regulated sealed lead-acid battery for energy storage made using the positive electrode lead paste provided in the embodiments of the present invention has better performance than the existing conventional valve-regulated sealed lead-acid batteries for energy storage.

[0043] Example 2 This embodiment provides a positive electrode paste for a valve-regulated sealed lead-acid battery, with the following specific composition: 1000 kg lead powder, 90 kg dilute sulfuric acid, 130 kg purified water, 1.6 kg short fiber, 0.9 kg antimony trioxide, 0.8 kg stannous sulfate, 2.3 kg graphite, 8.0 kg silica dispersion and 0.8 kg hydroxylamine sulfate.

[0044] The preparation method of the above-mentioned valve-regulated sealed lead-acid battery positive electrode lead paste includes the following steps: Weigh each component according to the above proportions, add the weighed lead powder to the automatic paste mixer, then add short fiber, antimony trioxide, stannous sulfate, graphite and hydroxylamine sulfate, dry stir for 5 minutes, add purified water while stirring, add all the purified water in 3 minutes, wet stir for 2 minutes to obtain the mixed slurry. The weighed silica dispersion was sprayed onto the surface of the mixed slurry while stirring. All the silica dispersion was added over 2 minutes, followed by wet stirring for 2 minutes. Cooling water was then turned on, and dilute sulfuric acid was added while stirring continuously. All the dilute sulfuric acid was added over 16 minutes. After adding acid for 5 minutes, the air-cooling system was turned on to ensure the lead paste temperature did not exceed 60°C during the mixing process. After adding acid, stirring continued for 12 minutes. When the lead paste temperature was below 45°C, the apparent density was measured. The apparent density of the lead paste was required to be 4.20 g / cm³. 3 ~4.30g / cm 3 , to obtain the positive electrode lead paste for valve-regulated sealed lead-acid batteries.

[0045] The valve-regulated sealed lead-acid battery positive electrode paste prepared above was used to assemble 6-CNF-200 (12V 200Ah) batteries through conventional processes in the art, including coating, curing and drying, separating, wrapping, electrode group welding, intermediate terminal bridging, and casing sealing. After acid injection and formation, capacity, low-temperature capacity, charging efficiency, and 100% DOD cycle tests were conducted according to the GB / T 22473.1 standard for energy storage lead-acid batteries. The testing methods were the same as in Example 1, and the specific results are shown in Table 3.

[0046] Table 3

[0047] A 6-CNF-200 (12V 200Ah) battery was made using conventional positive electrode lead paste (1000kg lead powder, 130kg purified water, 93kg dilute sulfuric acid, 0.6kg short fiber) and negative electrode lead paste (1000kg lead powder, 130kg purified water, 72kg dilute sulfuric acid, 0.6kg short fiber, 1.8kg acetylene black, 12kg barium sulfate, 2kg lignin) according to the same process described above. The battery was tested for various indicators using the same method as described above, and the results are shown in Table 2.

[0048] The results show that the valve-regulated sealed lead-acid battery for energy storage made using the positive electrode lead paste provided in the embodiments of the present invention has better performance than the existing conventional valve-regulated sealed lead-acid batteries for energy storage.

[0049] Example 3 This embodiment provides a positive electrode paste for a valve-regulated sealed lead-acid battery, with the following specific composition: 1000 kg lead powder, 95 kg dilute sulfuric acid, 120 kg purified water, 1.8 kg short fiber, 1.0 kg antimony trioxide, 0.6 kg stannous sulfate, 2.5 kg graphite, 10.0 kg silica dispersion and 1.0 kg hydroxylamine sulfate.

[0050] The preparation method of the above-mentioned valve-regulated sealed lead-acid battery positive electrode lead paste includes the following steps: Weigh each component according to the above proportions, add the weighed lead powder to the automatic paste mixer, then add short fiber, antimony trioxide, stannous sulfate, graphite and hydroxylamine sulfate, dry stir for 8 minutes, add purified water while stirring, add all the purified water in 2 minutes, wet stir for 2 minutes to obtain the mixed slurry. Spray the weighed silica dispersion onto the surface of the mixed slurry while stirring. Add all the silica dispersion over 3 minutes, then wet-stir for 3 minutes. Turn on the cooling water and add dilute sulfuric acid while stirring. Add all the dilute sulfuric acid over 20 minutes. After adding acid for 5 minutes, turn on the air-cooling system to ensure that the lead paste temperature does not exceed 60°C during the mixing process. After adding acid, continue stirring for 15 minutes. When the lead paste temperature is below 45°C, measure the apparent density. The apparent density of the lead paste should be 4.20 g / cm³. 3 ~4.30g / cm 3 , to obtain the positive electrode lead paste for valve-regulated sealed lead-acid batteries.

[0051] The valve-regulated sealed lead-acid battery positive electrode paste prepared above was used to assemble 6-CNF-200 (12V 200Ah) batteries through conventional processes in the art, including coating, curing and drying, separating, wrapping, electrode group welding, intermediate terminal bridging, and casing sealing. After acid injection and formation, capacity, low-temperature capacity, charging efficiency, and 100% DOD cycle tests were conducted according to the GB / T 22473.1 standard for energy storage lead-acid batteries. The testing methods were the same as in Example 1, and the specific results are shown in Table 4.

[0052] Table 4

[0053] A 6-CNF-200 (12V 200Ah) battery was made using conventional positive electrode lead paste (1000kg lead powder, 130kg purified water, 93kg dilute sulfuric acid, 0.6kg short fiber) and negative electrode lead paste (1000kg lead powder, 130kg purified water, 72kg dilute sulfuric acid, 0.6kg short fiber, 1.8kg acetylene black, 12kg barium sulfate, 2kg lignin) according to the same process described above. The battery was tested for various indicators using the same method as described above, and the results are shown in Table 2.

[0054] The results show that the valve-regulated sealed lead-acid battery for energy storage made using the positive electrode lead paste provided in the embodiments of the present invention has better performance than the existing conventional valve-regulated sealed lead-acid batteries for energy storage.

[0055] Comparative Example 1 This comparative example provides a positive electrode paste for a valve-regulated sealed lead-acid battery, which differs from Example 3 only in that it does not contain hydroxylamine sulfate; otherwise, the composition is identical. The specific components are as follows: 1000 parts lead powder, 95 parts dilute sulfuric acid, 120 parts purified water, 1.8 parts short fiber, 1.0 part antimony trioxide, 0.6 parts stannous sulfate, 2.5 parts graphite, and 10.0 parts silica dispersion.

[0056] Valve-regulated sealed lead-acid battery positive electrode paste was prepared using the same method as in Example 3. The prepared positive electrode paste was then used in the assembly of 6-CNF-200 (12V 200Ah) batteries through conventional processes including coating, curing and drying, separation, encapsulation, electrode group welding, intermediate terminal bridging, and casing sealing. After acid injection and formation, capacity, low-temperature capacity, charging efficiency, and 100% DOD cycle tests were performed according to GB / T 22473.1 energy storage lead-acid battery standard. The testing methods were the same as in Example 1, and the specific results are shown in Table 5.

[0057] Table 5

[0058] Comparative Example 2 This comparative example provides a positive electrode paste for a valve-regulated sealed lead-acid battery. The only difference from Example 3 is that the amount of hydroxylamine sulfate added is 0.15% of the lead powder mass. The specific composition is as follows: 1000 kg lead powder, 95 kg dilute sulfuric acid, 120 kg purified water, 1.8 kg short fiber, 1.0 kg antimony trioxide, 0.6 kg stannous sulfate, 2.5 kg graphite, 10.0 kg silica dispersion and 1.5 kg hydroxylamine sulfate.

[0059] Valve-regulated sealed lead-acid battery positive electrode paste was prepared using the same method as in Example 3. The prepared positive electrode paste was then used in conventional processes to assemble 6-CNF-200 (12V 200Ah) batteries, including coating, curing and drying, separation, encapsulation, electrode group welding, intermediate terminal bridging, and casing sealing. After acid injection and formation, capacity, low-temperature capacity, charging efficiency, and 100% DOD cycle tests were performed according to GB / T 22473.1 energy storage lead-acid battery standard. The testing methods were the same as in Example 1, and the specific results are shown in Table 6.

[0060] Table 6

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A valve-regulated sealed lead-acid battery positive electrode paste, characterized in that, Based on the mass of lead powder (100%), the additive components include the following mass percentages: antimony trioxide 0.08%~0.1%, stannous sulfate 0.05%~0.08%, graphite 0.2%~0.25%, silica dispersion 0.5%~1.0%, and hydroxylamine sulfate 0.05%~0.1%.

2. The valve-regulated sealed lead-acid battery positive electrode paste as described in claim 1, characterized in that, Based on the mass of lead powder as 100%, it also includes 9%~9.5% dilute sulfuric acid, 12%~13% water, and 0.15%~0.18% short fibers.

3. The valve-regulated sealed lead-acid battery positive electrode paste as described in claim 2, characterized in that, It comprises the following components in parts by weight: 1000 parts lead powder, 90-95 parts dilute sulfuric acid, 120-130 parts water, 1.5-1.8 parts short fiber, 0.8-1.0 parts antimony trioxide, 0.5-0.8 parts stannous sulfate, 2.0-2.5 parts graphite, 5.0-10 parts silica dispersion, and 0.5-1.0 parts hydroxylamine sulfate.

4. The positive electrode paste for valve-regulated sealed lead-acid batteries as described in any one of claims 1 to 3, characterized in that, The lead powder has an oxidation content of 71%~75% and an apparent density of 1.20 g / cm³. 3 ~1.40g / cm 3 (30 mesh sieve).

5. The positive electrode paste for valve-regulated sealed lead-acid batteries as described in any one of claims 1 to 3, characterized in that, The density of the dilute sulfuric acid at 25°C is 1.400 ± 0.002 g / cm³. 3 .

6. The positive electrode paste for valve-regulated sealed lead-acid batteries as described in any one of claims 1 to 3, characterized in that, The short fibers are polyester fibers with a length of 3mm to 5mm.

7. The positive electrode paste for valve-regulated sealed lead-acid batteries as described in any one of claims 1 to 3, characterized in that, The silica dispersion has a mass concentration of 15% to 20% and a silica particle size of 10 nm to 12 nm.

8. The positive electrode paste for valve-regulated sealed lead-acid batteries as described in any one of claims 1 to 3, characterized in that, The graphite has a particle size of 20μm to 30μm.

9. The method for preparing the positive electrode paste of the valve-regulated sealed lead-acid battery according to any one of claims 1 to 8, characterized in that, Includes the following steps: Weigh each raw material according to the formula of the positive electrode paste for valve-regulated sealed lead-acid batteries. Mix the weighed lead powder, short fiber, antimony trioxide, stannous sulfate, graphite and hydroxylamine sulfate evenly, add water, and obtain a mixed slurry. Spray silica dispersion into the mixed slurry, mix evenly, and then add dilute sulfuric acid to obtain valve-regulated sealed lead-acid battery positive electrode paste.

10. The method for preparing the positive electrode lead paste of a valve-regulated sealed lead-acid battery as described in claim 9, characterized in that, The apparent density of the positive electrode paste for the valve-regulated sealed lead-acid battery is 4.20 g / cm³. 3 ~4.30g / cm 3 .

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