Novel pole plate manufacturing process for improving performance of lead-carbon battery

Abstract

The invention relates to the technical field of lead-carbon batteries, and particularly discloses a novel polar plate manufacturing process for improving the performance of a lead-carbon battery. Comprising the following steps that S1, a metal lead ingot is subjected to melting and spray powdering, and lead powder is obtained; s2, carrying out ball milling treatment on the carbon material to obtain nano carbon powder; s3, lead powder and nano carbon powder are mixed to obtain mixed slurry; s4, dilute sulphuric acid is added into the mixed slurry, stirring continues, and lead paste is obtained; s5, the lead alloy plate grid is coated with the lead paste; s6, curing the coated plate grid; s7, drying the cured polar plate at the bottom; and S8, carrying out surface treatment on the dried polar plate. The manufacturing process of the novel polar plate with the lead-carbon battery performance can be applied to the fields of new energy automobile start-stop systems, distributed energy storage power stations, communication base station standby power supplies and low-speed electric vehicles, and has the advantages of high utilization rate of polar plate active substances, high battery rate performance, prolonged cycle life and controllable production cost.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of lead-carbon batteries, in particular to a new type of plate manufacturing process for improving the performance of lead-carbon batteries. BACKGROUND

[0002] The lead-carbon battery improves the electrode structure by adding carbon materials to the negative active material, has the low cost and high safety of the lead-acid battery, and the high rate charge-discharge capability of the super capacitor, and is widely used in new energy vehicle start-stop systems, distributed energy storage, communication base station standby power supply, micro-grid and low-speed electric vehicles and the like; the working principle is based on the "double sulfate reaction" of the lead-acid battery, and the high conductivity and large specific surface area of the carbon material are used to inhibit the growth of negative lead sulfate crystals, and at the same time, the electrode reaction kinetics rate is improved, the cycle life is prolonged, the charge-discharge rate is improved, the low temperature performance is improved, the capacity retention rate is higher, and the characteristics of the lead-acid battery raw materials are inherited, that is, the raw materials are easy to obtain, the manufacturing process is mature, and the recycling system is perfect; although the energy density is still lower than that of lithium battery, it is more suitable for low-cost, large-capacity energy storage and scenes with high safety requirements.

[0003] The related lead-carbon battery adds conventional carbon materials to the negative electrode to improve the conductivity and inhibit the lead sulfate crystal, but the compounding effect of these carbon materials with lead powder is poor, which leads to uneven dispersion of carbon particles in the lead matrix, and it is difficult to form an efficient three-dimensional conductive network, and the surface properties and size of the carbon material itself limit its weak capacitive buffering effect, which cannot alleviate the severe volume expansion and contraction of the lead active material during the charge and discharge process, thereby resulting in high internal resistance of the plate, poor electron transmission path and low utilization rate of the active material, and further limiting the improvement of the battery rate performance and shortening the cycle life. SUMMARY

[0004] In order to solve the problems of low utilization rate of active material of the plate, limited improvement of the battery rate performance and short cycle life of the related lead-carbon battery caused by adding conventional carbon materials to the negative electrode, the application provides a new type of plate manufacturing process for improving the performance of lead-carbon batteries.

[0005] The application provides a new type of plate manufacturing process for improving the performance of lead-carbon batteries, which adopts the following technical scheme:

[0006] The new type of plate manufacturing process for improving the performance of lead-carbon batteries comprises the following steps:

[0007] S1: melting, spraying and powdering the metal lead ingot to obtain lead powder;

[0008] S2: ball milling the carbon material to obtain nano carbon powder;

[0009] S3: mixing the lead powder obtained in step S1 and the nano-carbon powder obtained in step S2, adding deionized water, and stirring to obtain a mixed slurry;

[0010] S4: adding dilute sulfuric acid as an electrolyte to the mixed slurry of step S3, and continuing to stir to obtain a lead paste;

[0011] S5: coating the lead paste obtained in step S4 on a lead alloy grid;

[0012] S6: curing the coated grid;

[0013] S7: drying the cured grid under conditions to obtain the novel grid;

[0014] S8: performing surface treatment on the dried grid and rolling using a rolling machine.

[0015] By adopting the above technical solution, since the lead powder is prepared by melting and spray powdering of lead ingot, and the nano-carbon powder is obtained by ball milling of carbon material, then the lead powder and the nano-carbon powder are mixed and deionized water is added to form a slurry, and then dilute sulfuric acid is added to promote the formation of lead paste, and after coating on the lead alloy grid, curing, drying and rolling treatment, the microstructure and electrochemical performance of the grid are improved, so that the lead-carbon battery grid with high conductivity, high mechanical strength and long cycle life is obtained, and the overall performance of the battery is improved.

[0016] Preferably, in step S1, the melting temperature is 400-500℃, the spray pressure is 0.5-1.0 MPa, and the oxidation degree of the lead powder is controlled to be 20%-30%.

[0017] By adopting the above technical solution, since the melting temperature of 400-500℃ is adopted to ensure complete melting of the lead ingot without excessive oxidation, the spray pressure of 0.5-1.0 MPa is adopted to control the particle size and shape of the lead powder, and the oxidation degree of the lead powder is controlled to be 20%-30% to balance its reactivity and stability, so that the lead powder with suitable specific surface area and electrochemical activity is obtained, providing a uniform basis for subsequent mixing with carbon material.

[0018] Preferably, in step S2, the carbon material is one or more of activated carbon, graphene or carbon nanotube, and a dispersing agent is added during ball milling, the dispersing agent is polyvinylpyrrolidone, the amount is 1%-5% of the mass of the carbon material, and the ball milling time is 2-6h.

[0019] By adopting the above technical solution, high specific surface area carbon materials are used and refined to the nanoscale through ball milling. At the same time, polyvinylpyrrolidone is added as a dispersant at a dosage of 1%-5% of the carbon material mass to prevent carbon powder agglomeration and improve dispersibility. The ball milling time of 2-6 hours ensures the carbon material is refined, thus obtaining uniformly dispersed nano-carbon powder, which enhances the conductivity and capacitance characteristics of the electrode plate and provides a foundation for subsequent slurry preparation.

[0020] Preferably, in step S3, a binder is also added. The binder is polytetrafluoroethylene, and the amount is 0.5% to 2% of the total mass of lead powder and carbon powder. It is added at the beginning of stirring. The stirring parameters are as follows: stir at a speed of 200 to 500 rpm for 30 to 60 minutes.

[0021] By adopting the above technical solution, polytetrafluoroethylene is added as a binder to the mixed slurry at a dosage of 0.5%-2% of the total mass of lead powder and carbon powder to enhance the bonding strength and flexibility of the electrode plates. The slurry is added at the beginning of stirring to ensure uniform distribution. The slurry is stirred at a speed of 200-500 rpm for 30-60 minutes to mix it. Therefore, a mixed slurry with high fluidity and stability is obtained, which is convenient for subsequent coating.

[0022] Preferably, in step S3, the mass ratio of lead powder to nanopowder is 19:1 to 17:3.

[0023] By adopting the above technical solution, by controlling the mass ratio of lead powder and nano carbon powder to 19:1 to 17:3, the proportion of active materials is improved, ensuring that the lead component mainly conducts the chemical reaction while the carbon component provides the conductive network and capacitance effect. Therefore, a plate with balanced electrochemical performance and mechanical strength is obtained, thereby improving the rate performance and cycle stability of the battery.

[0024] Preferably, in step S4, the concentration of dilute sulfuric acid is 30-40 wt%, the amount added is 10%-20% of the lead powder mass, the addition temperature is 20-30°C, the stirring speed is 100-200 rpm, and the stirring time is 10-20 min.

[0025] By adopting the above technical solution, using 30-40wt% dilute sulfuric acid as the electrolyte, adding 10%-20% of the lead powder mass, adding it at a temperature of 20-30℃ to avoid violent reaction, and stirring at 100-200rpm for 10-20 minutes to promote the formation of lead sulfate and the curing of lead paste, a lead paste with suitable acidity and uniform reaction is obtained, ensuring the electrochemical activity and structural integrity of the electrode plate.

[0026] Preferably, in step S5, the lead alloy grid is a lead-calcium alloy or a lead-antimony alloy. Before coating, the grid is pretreated by pickling. The pickling solution is 5% to 10% dilute sulfuric acid, the treatment time is 1 to 5 minutes, and the coating thickness is 0.5 to 1.5 mm.

[0027] By adopting the above technical solution, since lead-calcium alloy or lead-antimony alloy is used as the grid material, acid washing pretreatment is performed before coating. The surface oxides and impurities are removed by treating with 5%-10% dilute sulfuric acid for 1-5 minutes, which enhances the adhesion between lead paste and grid. The coating thickness is controlled to 0.5-1.5 mm to improve the active material loading. Therefore, a plate with a stable bond and uniform thickness is obtained, which improves the current distribution and battery performance.

[0028] Preferably, in step S6, the curing process is divided into two stages: the first stage is cured for 6 to 12 hours at a humidity of 90% to 95% and a temperature of 30 to 40°C; the second stage is cured for 6 to 12 hours at a humidity of 80% to 85% and a temperature of 40 to 50°C.

[0029] By adopting the above technical solution, the curing process is divided into two stages. The first stage is cured for 6-12 hours at high humidity (90%-95%) and low temperature (30-40℃) to promote the initial hydration and crystal growth of the lead paste. The second stage is cured for 6-12 hours at lower humidity (80%-85%) and higher temperature (40-50℃) to complete the curing and reduce internal stress. Therefore, a dense and crack-free electrode plate is obtained, which improves the mechanical strength and electrochemical stability of the electrode plate.

[0030] Preferably, in step S7, the drying process is carried out under vacuum, with a vacuum degree of -0.08 to -0.1 MPa, a drying temperature of 60 to 80°C, and a drying time of 2 to 4 hours.

[0031] By adopting the above technical solution, drying is carried out in a vacuum environment with a vacuum degree of -0.08 to -0.1 MPa, a drying temperature of 60-80℃, and a time of 2-4 hours. This effectively removes moisture without causing deformation or oxidation of the electrode plate, thereby drying the electrode plate and improving its pore structure, providing a foundation for subsequent rolling processes.

[0032] Preferably, the rolling pressure is 5–10 MPa, and the density of the electrode plate after rolling is 4.0–4.5 g / cm³. 3 .

[0033] By adopting the above technical solution, and using a roller press for surface treatment at a pressure of 5-10 MPa, the electrode density can be controlled to reach 4.0-4.5 g / cm³. 3 This process compacts the active material and reduces porosity, resulting in a smooth-surfaced, uniformly dense electrode plate that improves conductivity, mechanical strength, and cycle performance.

[0034] In summary, this application has the following beneficial effects:

[0035] This application has the following beneficial effects:

[0036] 1. Since this application adopts the scheme of constructing the active material layer of the electrode plate by combining nano carbon powder and lead powder, the nano carbon powder forms a highly conductive network in the lead matrix, which not only enhances the electron transport efficiency, but also buffers the volume change of the lead active material during charging and discharging due to its own capacitance characteristics. Therefore, the effect of reducing the internal resistance of the electrode plate, improving the utilization rate of the active material, and simultaneously improving the rate performance and cycle life of the battery is achieved.

[0037] 2. In this application, a staged curing process is preferred. In the first stage, the growth and interweaving of basic lead sulfate crystals in the lead paste are promoted in a high humidity environment, which provides the basic mechanical strength of the electrode plate. In the second stage, the final curing is completed and the internal stress is released under moderate temperature and humidity conditions. Therefore, the electrode plate has a dense and uniform microstructure, avoids cracking and deformation, and has high electrochemical stability and mechanical durability.

[0038] 3. In this application, because the nano-carbon powder is stably and uniformly distributed in the lead matrix by means of dispersant and binder in the slurry preparation stage, the interfacial bonding strength between the active material and the current collector is improved by the grid acid washing pretreatment in the coating stage, and the stable formation of the electrode microstructure is achieved by controlling temperature and humidity in the curing and drying stage, the electrode preparation process has good reproducibility, high product consistency and easy to achieve large-scale production, and can suppress the shedding of active material and grid corrosion during charging and discharging. Attached Figure Description

[0039] Figure 1 This is a flowchart of the novel electrode manufacturing process for improving the performance of lead-carbon batteries proposed in this application. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0041] Example 1

[0042] This embodiment provides a novel electrode plate manufacturing process to improve the performance of lead-carbon batteries, comprising the following steps:

[0043] S1: Lead powder is obtained by melting and spraying lead ingots.

[0044] The melting temperature is 400℃, the spraying pressure is 0.5MPa, and the oxidation degree of the lead powder is controlled at 20%.

[0045] S2: The carbon material is ball-milled to obtain nano-carbon powder.

[0046] The carbon material is activated carbon. During ball milling, a dispersant, polyvinylpyrrolidone, is added at a rate of 1% of the carbon material mass, and the ball milling time is 2 hours.

[0047] S3: Mix the lead powder obtained in step S1 and the nano carbon powder obtained in step S2, add deionized water, and stir to obtain a mixed slurry.

[0048] Polytetrafluoroethylene (PTFE) binder was added, at a rate of 0.5% of the total mass of lead powder and carbon powder, and added at the beginning of stirring. The stirring parameters were as follows: stirring at 200 rpm for 30 minutes; the mass ratio of lead powder to nano carbon powder was 19:1.

[0049] S4: Add dilute sulfuric acid as an electrolyte to the mixed slurry from step S3, and continue stirring to obtain lead paste.

[0050] The concentration of dilute sulfuric acid is 30 wt%, the amount added is 10% of the lead powder mass, the addition temperature is 20℃, the stirring speed is 100 rpm, and the stirring time is 10 min.

[0051] S5: Apply the lead paste obtained in step S4 onto the lead alloy grid.

[0052] The lead alloy grid is made of lead-calcium alloy. Before coating, the grid is pretreated by pickling with 5% dilute sulfuric acid for 1 minute. The coating thickness is 0.5 mm.

[0053] S6: Curing the coated grid.

[0054] The curing process is divided into two stages: the first stage is curing for 6 hours at 90% humidity and 30℃; the second stage is curing for 6 hours at 80% humidity and 40℃.

[0055] S7: The cured electrode plate is dried in a dry environment to obtain the novel electrode plate.

[0056] The drying process is carried out under vacuum, with a vacuum level of -0.08 MPa, a drying temperature of 60°C, and a drying time of 2 hours.

[0057] S8: The dried electrode plates are surface treated by rolling with a roller press.

[0058] The rolling pressure is 5 MPa, and the density of the electrode plate after rolling is 4.0 g / cm³. 3 .

[0059] Example 2

[0060] This embodiment provides a novel electrode plate manufacturing process to improve the performance of lead-carbon batteries, comprising the following steps:

[0061] S1: Lead powder is obtained by melting and spraying lead ingots.

[0062] The melting temperature is 450℃, the spraying pressure is 0.75MPa, and the oxidation degree of the lead powder is controlled at 25%.

[0063] S2: The carbon material is ball-milled to obtain nano-carbon powder.

[0064] The carbon material is graphene. During ball milling, polyvinylpyrrolidone (PVP) is added as a dispersant at 3% of the mass of the carbon material, and the ball milling time is 4 hours.

[0065] S3: Mix the lead powder obtained in step S1 and the nano carbon powder obtained in step S2, add deionized water, and stir to obtain a mixed slurry.

[0066] Polytetrafluoroethylene (PTFE) binder was added, at a dosage of 1.25% of the total mass of lead powder and carbon powder, and added at the beginning of stirring. The stirring parameters were as follows: stirring at 350 rpm for 45 minutes; the mass ratio of lead powder to nano carbon powder was 9:1.

[0067] S4: Add dilute sulfuric acid as an electrolyte to the mixed slurry from step S3, and continue stirring to obtain lead paste.

[0068] The concentration of dilute sulfuric acid is 35 wt%, the amount added is 15% of the lead powder mass, the addition temperature is 25℃, the stirring speed is 150 rpm, and the stirring time is 15 min.

[0069] S5: Apply the lead paste obtained in step S4 onto the lead alloy grid.

[0070] The lead alloy grid is made of lead-antimony alloy. Before coating, the grid is pretreated by pickling. The pickling solution is 7.5% dilute sulfuric acid, the treatment time is 3 minutes, and the coating thickness is 1.0 mm.

[0071] S6: Curing the coated grid.

[0072] The curing process is divided into two stages: the first stage is cured for 9 hours at 92.5% humidity and 35℃; the second stage is cured for 9 hours at 82.5% humidity and 45℃.

[0073] S7: The cured electrode plate is dried in a dry environment to obtain the novel electrode plate.

[0074] The drying process is carried out in a vacuum environment with a vacuum degree of -0.09MPa, a drying temperature of 70℃, and a drying time of 3h.

[0075] S8: The dried electrode plates are surface treated by rolling with a roller press.

[0076] The rolling pressure is 7.5 MPa, and the density of the electrode plate after rolling is 4.25 g / cm³. 3 .

[0077] Example 3

[0078] This embodiment provides a novel electrode plate manufacturing process to improve the performance of lead-carbon batteries, comprising the following steps:

[0079] S1: Lead powder is obtained by melting and spraying lead ingots.

[0080] The melting temperature is 500℃, the spraying pressure is 1.0MPa, and the oxidation degree of the lead powder is controlled at 30%.

[0081] S2: The carbon material is ball-milled to obtain nano-carbon powder.

[0082] The carbon material is carbon nanotubes. During ball milling, polyvinylpyrrolidone (PVP) is added as a dispersant at 5% of the mass of the carbon material, and the ball milling time is 6 hours.

[0083] S3: Mix the lead powder obtained in step S1 and the nano carbon powder obtained in step S2, add deionized water, and stir to obtain a mixed slurry.

[0084] Polytetrafluoroethylene (PTFE) binder was added, at a rate of 2% of the total mass of lead powder and carbon powder, and added at the beginning of stirring. The stirring parameters were as follows: stirring at 500 rpm for 60 minutes; the mass ratio of lead powder to nano carbon powder was 17:3.

[0085] S4: Add dilute sulfuric acid as an electrolyte to the mixed slurry from step S3, and continue stirring to obtain lead paste.

[0086] The concentration of dilute sulfuric acid is 40 wt%, the amount added is 20% of the lead powder mass, the addition temperature is 30℃, the stirring speed is 200 rpm, and the stirring time is 20 min.

[0087] S5: Apply the lead paste obtained in step S4 onto the lead alloy grid.

[0088] The lead alloy grid is a lead-calcium alloy. Before coating, the grid is pretreated by pickling with 10% dilute sulfuric acid for 5 minutes. The coating thickness is 1.5 mm.

[0089] S6: Curing the coated grid.

[0090] The curing process is divided into two stages: the first stage is curing for 12 hours at 95% humidity and 40℃; the second stage is curing for 12 hours at 85% humidity and 50℃.

[0091] S7: The cured electrode plate is dried in a dry environment to obtain the novel electrode plate.

[0092] The drying process is carried out in a vacuum environment with a vacuum degree of -0.1MPa, a drying temperature of 80℃, and a drying time of 4h.

[0093] S8: The dried electrode plates are surface treated by rolling with a roller press.

[0094] The rolling pressure is 10 MPa, and the density of the electrode plate after rolling is 4.5 g / cm³. 3 .

[0095] Comparative Example 1

[0096] This comparative example refers to the content of Example 1, except that the melting temperature in step S1 is 350°C, and the rest is the same as in Example 1.

[0097] Comparative Example 2

[0098] This comparative example refers to the content of Example 1, except that the spray pressure in step S1 is 1.3 MPa, and the rest is the same as Example 1.

[0099] Comparative Example 3

[0100] The comparative example refers to the content of Example 1, except that the oxidation degree of lead powder is controlled to be 35% in step S1, and the rest is the same as in Example 1.

[0101] Comparative Example 4

[0102] The comparative example refers to the content of Example 1, except that the carbon material in step S2 is carbon black, and the rest is the same as in Example 1.

[0103] Comparative Example 5

[0104] The comparative example refers to the content of Example 1, except that the amount of polytetrafluoroethylene binder used in step S3 is 0.3% of the total mass of lead powder and carbon powder, and the rest is the same as in Example 1.

[0105] Comparative Example 6

[0106] The comparative example refers to the content of Example 1, except that the first stage of the curing process in step S6 is cured for 6 hours at 70% humidity and 30°C, and the rest is the same as in Example 1.

[0107] Performance testing

[0108] Sample preparation: The plates prepared in Examples 1-3 and Comparative Examples 1-6 were used as test samples. At least five plates of each type were prepared for subsequent performance tests. All plates were assembled into standard lead-carbon single cells under the same conditions before testing and the prescribed charge-discharge initialization process was completed.

[0109] Plate internal resistance test: A four-terminal DC internal resistance tester was used to test the assembled single cell at 50% charge and 25°C. First, the battery was allowed to stand for 30 minutes to ensure voltage stability. Then, a large current pulse lasting 30 seconds was applied, and the voltage change value at the moment the pulse started was recorded to obtain the DC internal resistance of the plate. The test standard refers to the recommended method for battery internal resistance test in GB / T19639.1-2014.

[0110] Battery rate discharge performance test: After initialization, the battery is discharged at a constant temperature of 25℃ to the termination voltage at a rate of 0.2C, and its rated capacity is recorded. Then, the battery is fully charged and discharged at 1C and 2C rates to the same termination voltage, and the actual discharge capacity at each rate is recorded. The percentage of high-rate discharge capacity to rated capacity is then obtained. The test standard refers to the test requirements for high-current discharge performance of lead-acid batteries in GB / T22473-2008.

[0111] Test for the adhesive strength of the active material on the electrode plate: First, cut a standard-sized sample from the cured and dried electrode plate, and use a universal testing machine to perform a 90-degree peel strength test. The testing machine stretches the coated active material layer from the grid at a constant speed, continuously records the force change during the peeling process, and calculates the average peel strength; the test standard refers to "GB / T2792-2014 Test method for peel strength of adhesives".

[0112] Battery cycle life test: First, the battery is placed in a 25°C constant temperature chamber for accelerated cycle life test; each cycle includes deep discharge at a certain current, followed by constant voltage current-limited charging; every certain number of cycles, a capacity calibration discharge is performed, and when the battery discharge capacity decays to 80% of the rated capacity, the number of cycles experienced is recorded as the end point of the battery's life; the test standard refers to the cycle durability test method in "IEC60896-21:2004 Stationary Valve-Regulated Lead-Acid Batteries".

[0113] Detection of porosity and specific surface area of ​​active material on electrode plates: First, the electrode plate sample is crushed, and an appropriate amount of active material powder is degassed under vacuum to remove surface physical adsorbates; then, nitrogen gas is adsorbed and desorbed on the sample surface at liquid nitrogen temperature. The specific surface area is calculated by analyzing the adsorption isotherm and by using the BET model, and the porosity and pore size distribution are calculated by using the BJH model; the test standard refers to "GB / T19587-2004 Determination of Specific Surface Area of ​​Solid Materials by Gas Adsorption BET Method".

[0114] Table 1:

[0115]

[0116] Example Conclusion:

[0117] As can be seen from Examples 1-3 and Comparative Example 1 and Table 1, the melting temperature of lead ingots can affect the physical properties and reactivity of lead powder. When the melting temperature is too low, the lead ingots fail to melt and atomize sufficiently, resulting in coarse and uneven lead powder particles, which weakens its specific surface area and electrochemical activity as an active material, thereby deteriorating the conductivity of the final electrode plate and causing a simultaneous decrease in the rate performance and cycle life of the battery.

[0118] As can be seen from Examples 1-3 and Comparative Example 2 and Table 1, the spray powder pressure parameters affect the particle size distribution and morphology of lead powder. Excessive spray pressure can cause lead powder particles to undergo excessive collision and cold work hardening due to excessive kinetic energy. This not only increases the oxidation tendency of lead powder but also destroys the sphericity of the particles, making it difficult to form dense accumulation during subsequent lead paste preparation. Ultimately, this leads to the deterioration of the electrode pore structure, increased internal resistance, and insufficient capacity retention.

[0119] As can be seen from Examples 1-3 and Comparative Example 3 and Table 1, controlling the oxidation degree of lead powder can balance its chemical activity and stability. Excessive oxidation degree means that the lead oxide content in the lead powder exceeds the standard. It will react violently with dilute sulfuric acid during the paste mixing stage, generating a large amount of lead sulfate prematurely. This not only damages the structure of the lead paste, but also forms a large amount of inactive inert substances inside the electrode plate, thereby reducing the utilization rate of active materials and the durability of the battery.

[0120] Combined with Examples 1-3 and Comparative Example 4 and Table 1, it can be seen that the selection of carbon material type can construct a highly efficient conductive network. Among them, the use of ordinary carbon black to replace specific nano-carbon materials, although the specific surface area is large, has a low degree of graphitization, poor conductivity and lack of pseudocapacitive properties, and cannot form an electronic conduction path and buffer matrix in the lead matrix, resulting in extremely high internal resistance of the electrode plate, and the rate performance and cycle stability do not meet the standards.

[0121] As can be seen from Examples 1-3 and Comparative Example 5 and Table 1, the amount of binder affects the mechanical strength of the bonding between active materials and between them and the grid. When the amount of binder is insufficient, it is impossible to wrap and connect the lead powder and carbon powder particles, and it is also impossible to form a stable bonding interface between the active material layer and the grid, resulting in poor structural integrity of the plate. During the charging and discharging process, the active material is easy to soften and fall off, thereby shortening the cycle life of the battery.

[0122] As can be seen from Examples 1-3 and Comparative Example 6, and Table 1, the ambient humidity during the initial curing stage can ensure the growth of basic lead sulfate crystals in the lead paste. If the humidity is too low, the lead paste will lose water too quickly, resulting in incomplete crystal growth and failure to interweave to form a strong skeleton structure. This leads to insufficient mechanical strength of the electrode plate, microcracks inside, and ultimately low electrode plate peel strength, making it easy to deform and be damaged during cycling, thus reducing battery life.

[0123] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A novel electrode plate manufacturing process for improving the performance of lead-carbon batteries, characterized in that, Includes the following steps: S1: Lead powder is obtained by melting and spraying lead ingots; S2: The carbon material is ball-milled to obtain nano-carbon powder; S3: Mix the lead powder obtained in step S1 and the nano carbon powder obtained in step S2, add deionized water, and stir to obtain a mixed slurry; S4: Add dilute sulfuric acid as an electrolyte to the mixed slurry in step S3, and continue stirring to obtain lead paste; S5: Apply the lead paste obtained in step S4 onto the lead alloy grid; S6: Curing the coated grid; S7: Dry the cured electrode plate below to obtain the novel electrode plate; S8: The dried electrode plates are surface treated by rolling with a roller press.

2. The novel electrode plate manufacturing process for improving the performance of lead-carbon batteries according to claim 1, characterized in that, In step S1, the melting temperature is 400–500°C, the spray pressure is 0.5–1.0 MPa, and the oxidation degree of the lead powder is controlled to be 20%–30%.

3. The novel electrode plate manufacturing process for improving the performance of lead-carbon batteries according to claim 1, characterized in that, In step S2, the carbon material is one or more of activated carbon, graphene, or carbon nanotubes. A dispersant, polyvinylpyrrolidone, is added during ball milling. The amount of dispersant is 1% to 5% of the mass of the carbon material, and the ball milling time is 2 to 6 hours.

4. The novel electrode plate manufacturing process for improving the performance of lead-carbon batteries according to claim 1, characterized in that, In step S3, a binder is also added. The binder is polytetrafluoroethylene, and the amount is 0.5% to 2% of the total mass of lead powder and carbon powder. It is added at the beginning of stirring. The stirring parameters are as follows: stir at a speed of 200 to 500 rpm for 30 to 60 minutes.

5. The novel electrode plate manufacturing process for improving the performance of lead-carbon batteries according to claim 1, characterized in that, In step S3, the mass ratio of lead powder to nanopowder is 19:1 to 17:

3.

6. The novel electrode plate manufacturing process for improving the performance of lead-carbon batteries according to claim 1, characterized in that, In step S4, the concentration of dilute sulfuric acid is 30-40 wt%, the amount added is 10%-20% of the lead powder mass, the addition temperature is 20-30℃, the stirring speed is 100-200 rpm, and the stirring time is 10-20 min.

7. The novel electrode plate manufacturing process for improving the performance of lead-carbon batteries according to claim 1, characterized in that, In step S5, the lead alloy grid is a lead-calcium alloy or a lead-antimony alloy. Before coating, the grid is pretreated by pickling. The pickling solution is 5% to 10% dilute sulfuric acid, the treatment time is 1 to 5 minutes, and the coating thickness is 0.5 to 1.5 mm.

8. The novel electrode plate manufacturing process for improving the performance of lead-carbon batteries according to claim 1, characterized in that, In step S6, the curing process is divided into two stages: the first stage is cured for 6 to 12 hours at a humidity of 90% to 95% and a temperature of 30 to 40°C; the second stage is cured for 6 to 12 hours at a humidity of 80% to 85% and a temperature of 40 to 50°C.

9. The novel electrode plate manufacturing process for improving the performance of lead-carbon batteries according to claim 1, characterized in that, In step S7, the drying process is carried out under vacuum, with a vacuum degree of -0.08 to -0.1 MPa, a drying temperature of 60 to 80°C, and a drying time of 2 to 4 hours.

10. The novel electrode plate manufacturing process for improving the performance of lead-carbon batteries according to claim 1, characterized in that, The rolling pressure is 5–10 MPa, and the density of the electrode plate after rolling is 4.0–4.5 g / cm³. 3 .

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