Curing process of storage battery electrode plate

Abstract

The invention relates to the technical field of battery manufacturing, and particularly discloses a curing process of a storage battery electrode plate, which comprises the following specific steps of: reducing the content of free lead in lead paste to be less than 14% by adopting the conditions of the humidity of more than 95% and the temperature of 42-50 DEG C, and promoting lead oxide to be converted into a tribasic lead sulfate crystal phase; the curing temperature is raised to 65 DEG C, the humidity is kept to be 95%, formation of a tetrabasic lead sulfate crystal phase is promoted, a ventilation control strategy is adopted, water evaporation is accelerated, and the drying time is shortened; and a temperature control drying technology is adopted, so that the moisture content is reduced to 0.1% or below. The curing time of the lead-acid battery pole plate is shortened, the mechanical strength of the pole plate is enhanced, and the cycle life of the pole plate is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of battery manufacturing, and more specifically, to a curing process for a battery plate. Background Art

[0002] In the manufacturing process of lead-acid batteries, the curing process of the plate is one of the key links that affect the performance of the battery. The curing process includes oxidation reaction, crystal phase transformation and plate drying to ensure the adhesion, porosity and electrochemical stability of the active material.

[0003] The existing public document 1 (Research on High-temperature Curing Process of Lead-acid Battery Positive Plate, 2016) discloses the high-temperature curing process of lead-acid battery positive plate. The specific steps of this process are: prepare samples by setting curing temperature (80℃, 100℃, 120℃) and time (2-10h) variables, and use a variety of test methods to test the performance of the plate and battery; study the performance of the plate after curing under different conditions, including appearance, component structure, micromorphology, etc., and also conduct internalization experiments and capacity testing and batch verification; for the problem of poor uniformity of battery capacity during high-temperature curing (80℃×6h), analyze the reasons and propose a solution to add "4BS seed crystals", and study its effect on the performance of the plate and battery through experiments. However, when the curing temperature reaches above 100℃, the surface of the plate will "bulge", affecting the stability of the plate.

[0004] The existing open document 2 (Study on the Preparation Process of Bipolar Plates for Lead-acid Batteries and Battery Performance, 2016) discloses a preparation process for bipolar plates for lead-acid batteries. The process first prepares a variety of base materials to make bipolar substrates with different structures, such as degreasing and washing pure titanium metal plates or removing oxide films, and electroplating other metal plates; then, paste is mixed, short fibers, water, lead powder and additives are added to the paste mixing vessel in sequence, stirred evenly, and the temperature and acid addition speed are controlled according to the process to adjust the lead paste density and consistency; then, the mixed lead paste is coated on the substrate to ensure uniform weight and thickness, and acid treatment is performed; finally, a low-temperature or high-temperature curing process is used, and the acid-treated plates are placed in a programmable constant temperature and humidity chamber for curing. However, the process involves a variety of materials and complex operating steps, and the curing time will also increase accordingly, which is not conducive to large-scale industrial production.

[0005] Therefore, there is an urgent need for a curing process that can shorten the curing time of lead-acid battery plates and improve the stability of lead-acid battery plates. Summary of the invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a curing process for battery plates, which accelerates the conversion of lead oxide into tribasic lead sulfate crystalline phase through specific temperature and humidity conditions, accelerates water evaporation and reduces drying time by optimizing ventilation control strategy, and adopts temperature-controlled drying technology to avoid cracks caused by excessive drying of the plates, thereby solving the problems raised in the above-mentioned background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions: A curing process for a battery plate comprises the following steps: Step S1, using a humidity of more than 95% and a temperature of 42-50° C. to reduce the free lead content of the lead paste to less than 14%, thereby promoting the conversion of lead oxide into a tribasic lead sulfate crystal phase; Step S2, raising the curing temperature to 65° C., maintaining a humidity of 95% to promote the formation of a tetrabasic lead sulfate crystal phase, and adopting a ventilation control strategy to accelerate water evaporation and reduce drying time; Step S3, using temperature-controlled drying technology to reduce the moisture content to below 0.1%, ensuring that the plate is completely dry without cracks; The ventilation control strategy includes the following specific steps: Step Z1: deploy humidity sensors in the curing room. Assume that the curing room is divided into N areas. The humidity value of each area is measured by the humidity sensor to obtain the humidity value of each area at time t. : ,in, represents the humidity value at time t in the first area, represents the humidity value at time t in the second area, Represents the humidity value at time t in the Nth region; and calculates the global average humidity value : , Indicates the curing room Regions, For the The humidity value in the area at time t; then the humidity gradient value The calculation formula is: ,like , it means that the humidity in the curing room has reached a balanced state, and there is no need to adjust the wind speed and direction. To set the threshold; if , then go to the next step to adjust the wind speed and direction.

[0008] Preferably, in step Z2, a wind speed adjustment model is constructed to control the wind speed adjustment amount so that it can dynamically respond to changes in humidity in the curing room to avoid the problem of uneven curing effect caused by too fast or too slow adjustment. The calculation formula of the wind speed adjustment model is: ,in, For the The wind speed adjustment in a region at time t; For the Time in the region The wind speed adjustment at the moment; It is a proportional control item, reflecting the impact of the current humidity deviation on the wind speed; is the integral control term; Indicates that from the initial moment All historical time steps between now and the current time t; Describe the first Regions in historical time Humidity measurement value at the moment; Indicates historical time The average humidity value in the curing room at the moment; T represents the sampling interval; is the differential control term; is an adaptive adjustment factor used to adjust the dynamic changes of wind speed. In addition, the wind speed limit is increased to ensure that the wind speed does not exceed the physical safety range: , is the preset minimum allowable wind speed value, It is the preset maximum allowed wind speed value.

[0009] Preferably, in step Z3, in order to optimize the air flow path and reduce the local humidity direct current, the wind direction angle adjustment rule is defined: ,in, is the wind direction angle, representing the direction of air flow; Indicates the curing room The wind direction angle of a region at time t; Indicates the curing room Regions in time The wind direction at the moment; Adjust the gain for wind direction and control the sensitivity of wind direction changes; Beyond 0°-180°, adjust the limit: .

[0010] Preferably, the step Z4 adopts closed-loop control, recalculates the wind speed and wind direction at each time interval T, and performs the following iterations: 1. Calculates the humidity gradient ; 2. Calculate the wind speed adjustment And update the wind speed; 3. Calculate the wind direction adjustment And update the wind direction; 4. Enter the next time step , and continue the cycle.

[0011] Preferably, in step S1, a humidity of more than 95% and a temperature of 42-50°C are used to reduce the free lead content of the lead paste to less than 14%, and at the same time promote the conversion of lead oxide into tribasic lead sulfate crystal phase, including the following specific contents: first, ensure that the humidity of the lead paste is between 10-14% to ensure uniform coating of the active material. Arrange the freshly coated lead paste plates neatly on a metal bracket or a special curing rack to ensure that the airflow can be evenly distributed between all the plates, thereby avoiding the problem of insufficient or excessive local curing. Then the plates are sent to a curing chamber, and the temperature in the curing chamber is set between 42-50°C to prevent the lead paste from being dehydrated too quickly due to excessively high temperature, or the hydration reaction rate of lead oxide (PbO) from being reduced due to too low temperature. At the same time, the humidity of the curing chamber is set to more than 95% by a water spray humidification system to ensure that the water in the lead paste does not evaporate too quickly, but gradually participates in the hydration and sulfation reactions of PbO.

[0012] Preferably, in the initial stage of the curing process, the PbO in the lead paste first combines with water to form lead hydroxide (Pb(OH) 2 ), then, under the action of sulfuric acid vapor, Pb(OH) 2 Gradually converted into tribasic lead sulfate (3BS).

[0013] Preferably, in step S2, the curing temperature is raised to 65°C, the humidity is maintained at 95%, the formation of tetrabasic lead sulfate crystal phase is promoted, an optimized ventilation control strategy is adopted, water evaporation is accelerated, and the drying time is reduced, including the following specific contents: the temperature of the curing chamber is gradually increased from 42-50°C to 65°C, and this temperature increase process is completed within 4-6 hours, ensuring that the temperature increase does not cause a sharp loss of water on the surface of the plate and affect the uniformity of curing. At the same time, the humidity still needs to be maintained at more than 95% to ensure that the hydration reaction inside the lead paste can proceed smoothly, and the binding force between the lead paste particles will not be reduced due to too fast water evaporation, thereby affecting the structural stability of the plate.

[0014] Preferably, in order to accelerate the evaporation of water while preventing the surface of the plate from drying out too quickly and causing cracks that affect the curing quality, a ventilation control strategy is adopted.

[0015] Preferably, in step S3, temperature-controlled drying technology is used to reduce the moisture content to below 0.1%, ensuring that the plate is completely dried without cracks, including the following specific contents: the temperature-controlled drying technology includes three stages: pre-drying stage, medium-temperature diffusion drying stage and uniform drying stage, to ensure that the plate is evenly discharged during the drying process and to avoid structural damage caused by excessive temperature rise. In the pre-drying stage (0-8 hours), the plate is placed in a drying chamber with high humidity (>35%RH) and low temperature (40-50°C). The main purpose of this stage is to promote the diffusion of moisture from the inside of the plate to the outside through capillary action, while reducing the moisture gradient inside the plate, and avoiding the surface moisture from evaporating too quickly to cause the surface layer to harden. In the medium-temperature diffusion drying stage (8-24 hours), the drying temperature is gradually increased to 60-70°C, and the humidity is reduced to 15-25%RH. The goal of this stage is to accelerate the diffusion and dehydration process of moisture. In order to further optimize the moisture diffusion rate, an intermittent heating strategy was adopted, that is, the temperature was increased by 5°C every 2-4 hours, and the humidity was reduced by 5% simultaneously, so that the dehydration rate was consistent with the moisture diffusion rate. In the uniform drying stage (24-32 hours), the drying temperature was controlled at 75-80°C, the humidity was reduced to 5-10%RH, and the evaporation of water was accelerated by the air convection system. At this time, the moisture content of the plate dropped to about 1.0%, but further drying was still required to ensure that the moisture content dropped below 0.1%. In this stage, the wind speed was first increased to 1.5-2.0m / s to accelerate the evaporation of water, and then the wind speed was gradually reduced to 0.8m / s in the last 4 hours to avoid the generation of surface cracks due to excessive wind force. In addition, to ensure uniform temperature, infrared thermal imaging monitoring technology was also used in the drying process to monitor the temperature distribution on the surface of the plate in real time, and when the local temperature deviation exceeded ±2°C, the position of the heating element or the air flow direction was adjusted to ensure uniform heating of the plate, further reduce thermal stress, and prevent the generation of microcracks.

[0016] The technical effects and advantages of the curing process of a battery plate of the present invention are as follows: In the initial stage, through specific temperature and humidity conditions (humidity above 95% and temperature of 42-50°C), the transformation of lead oxide into tribasic lead sulfate crystal phase is accelerated, the free lead content is reduced, and the curing efficiency is improved. Compared with the traditional process, this stage of curing can be completed in a shorter time. In the process of heating to 65°C and maintaining high humidity, not only the formation of tetrabasic lead sulfate crystal phase is promoted, the conductivity and mechanical strength of the plate are improved, but also the wind speed and wind direction are dynamically adjusted according to the humidity gradient value by optimizing the ventilation control strategy, accelerating the evaporation of water and reducing the drying time, and the evaporation rate of water is increased by about 30%. The final temperature-controlled drying technology adopts three stages of pre-drying, medium-temperature diffusion drying and uniform drying to control temperature, humidity and air flow, avoid cracks caused by too fast drying of the plate, and ensure uniform discharge of water. The present invention significantly shortens the curing time of the lead-acid battery plate, improves the stability of the plate, enhances the mechanical strength and cycle life of the plate, and thus prolongs the service life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a method flow chart of a curing process for a battery plate.

[0018] Figure 2 This is a schematic diagram comparing the porosity of positive plates under different curing conditions in the high-temperature curing process of positive plates of lead-acid batteries in the prior art.

[0019] Figure 3 The present invention is a flow chart of the preparation process of a bipolar lead-acid battery in the prior art process of preparing bipolar plates for lead-acid batteries.

[0020] Figure 4 This is a schematic diagram of the change of 3BS generation rate over time according to the present invention.

[0021] Figure 5 Schematic diagram of the effect of the ventilation control strategy of the present invention on the water evaporation rate. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1 See also Figure 1 As shown in the flowchart, the embodiment of the present invention provides a curing process for a battery plate, which includes the following steps: Step S1, using humidity above 95% and temperature of 42-50°C to reduce the free lead content of the lead paste to below 14%, thereby promoting the conversion of lead oxide into tribasic lead sulfate crystal phase.

[0024] Step S2, raising the curing temperature to 65°C, maintaining a humidity of 95% to promote the formation of a tetrabasic lead sulfate crystal phase, and adopting a ventilation control strategy to accelerate water evaporation and reduce drying time.

[0025] Step S3, using temperature-controlled drying technology to reduce the moisture content to below 0.1%, ensuring that the plate is completely dry without cracks.

[0026] In this embodiment, see Figure 2 The schematic diagram shown is a high-temperature curing process for the positive plate of a lead-acid battery disclosed in the prior art. The specific steps of the process are: preparing samples by setting the curing temperature (80°C, 100°C, 120°C) and time (2-10h) variables, and using a variety of test methods to detect the performance of the plate and battery; studying the performance of the plate after curing under different conditions, including appearance, component structure, micromorphology, etc., and also conducting internalization experiments, capacity testing and batch verification; in response to the problem of poor uniformity of battery capacity after high-temperature curing (80°C×6h), the cause was analyzed and a solution of adding "4BS seed crystals" was proposed, and its effect on the performance of the plate and battery was studied experimentally. However, when the curing temperature of this process reaches above 100°C, a "bulging" phenomenon will occur on the surface of the plate, affecting the stability of the plate. See also Figure 3 The flowchart shown is a process for preparing bipolar plates for lead-acid batteries disclosed in the prior art. The process first prepares a variety of base materials to make bipolar substrates with different structures, such as degreasing and washing pure titanium metal plates or removing oxide films, and electroplating other metal plates; then, paste is mixed, short fibers, water, lead powder and additives are added to the paste mixing vessel in sequence, stirred evenly, and the temperature and acid addition speed are controlled according to the process to adjust the lead paste density and consistency; then, the mixed lead paste is coated on the substrate to ensure uniform weight and thickness, and acid treatment is performed; finally, a low-temperature or high-temperature curing process is used to place the acid-treated plates in a programmable constant temperature and humidity chamber for curing. However, the process involves a variety of materials and complex operating steps, and the curing time will also increase accordingly, which is not conducive to large-scale industrial production.

[0027] In step S1, a humidity of more than 95% and a temperature of 42-50°C are used to reduce the free lead content of the lead paste to less than 14%, and at the same time promote the conversion of lead oxide into a tribasic lead sulfate crystal phase, including: first, ensuring that the humidity of the lead paste is between 10-14% to ensure uniform coating of the active material and to maintain good adhesion and porosity during the subsequent curing process. The freshly coated lead paste plates are neatly arranged on a metal bracket or a special curing rack to ensure that the airflow can be evenly distributed between all the plates, thereby avoiding the problem of local insufficient curing or over-curing. The plates are then sent to a curing chamber, and the temperature in the curing chamber is set between 42-50°C to prevent the lead paste from being dehydrated too quickly due to excessively high temperatures, or the hydration reaction rate of lead oxide (PbO) from being reduced due to too low temperatures. At the same time, the humidity of the curing chamber is set to more than 95% by a water spray humidification system to ensure that the water in the lead paste does not evaporate too quickly, but gradually participates in the hydration and sulfation reactions of PbO.

[0028] In the initial stage of the curing process, the PbO in the lead paste first combines with water to form lead hydroxide (Pb(OH) 2 ), then, under the action of sulfuric acid vapor, Pb(OH) 2 Gradually converted to tribasic lead sulfate (3BS). Figure 4 As shown in the curve, the generation rate of 3BS is optimized under the effect of humidity above 95% and temperature of 42-50°C. It can be seen from the figure that under the conditions of 95% humidity and 42-50°C, the formation rate of 3BS crystal phase is fast, reaching more than 85% after about 8 hours; under the conditions of 5% humidity and 35-40°C, the formation of 3BS crystal phase is slow, and it takes 12 hours to reach 85%. Within the first 8 hours of the curing process, a high proportion of 3BS crystal phase is formed on the surface and inside of the plate, and the free lead content (FLC%) in the lead paste is rapidly reduced from the initial 22-25% to below 14%. The following Table 1 shows the specific experimental data.

[0029] Table 1 Comparison of 3BS formation and free lead (FLC%) reduction rate during lead-acid battery plate curing process Time (hours) 3BS formation ratio (%)-optimized process 3BS formation ratio (%) - conventional process Free Lead Content (FLC%)-Optimized Process Free Lead Content (FLC%) - Traditional Process 0 0 0 24 25 1 5 2 22 24 2 12 5 19 22 3 22 10 17 21 4 35 18 15 19 5 50 28 14 17 6 65 40 13.5 16 7 78 55 13 15 8 85 70 12.8 14.5 The optimized process in Table 1 is at a humidity of 95% and a temperature of 42-50°C; the traditional process is at a humidity of 85% and a temperature of 35-40°C. Experiments show that the use of humidity above 95% and a temperature of 42-50°C can significantly accelerate the formation of the 3BS crystal phase and improve the efficiency of plate curing. Within 8 hours, the optimized process can reduce the FLC% to below 14%, meeting the goal of rapid curing, while the traditional process takes longer to achieve the same effect.

[0030] In step S2, the curing temperature is raised to 65°C, the humidity is maintained at 95%, the formation of the tetrabasic lead sulfate crystal phase is promoted, and an optimized ventilation control strategy is adopted to accelerate the evaporation of water and reduce the drying time, including: gradually raising the temperature of the curing chamber from 42-50°C to 65°C, and this heating process is completed within 4-6 hours, ensuring that the temperature increase does not cause a sharp loss of water on the surface of the plate and affect the uniformity of curing. At the same time, the humidity still needs to be maintained above 95% to ensure that the hydration reaction inside the lead paste can proceed smoothly, and the binding force between the lead paste particles will not be reduced due to too fast evaporation of water, thereby affecting the structural stability of the plate.

[0031] In this example, the study showed that maintaining a high humidity environment helps reduce the direct formation of PbO into PbSO 4 The adverse reaction of PbO to 4BS is reduced, so that more of it is converted into 4BS, which improves the conductivity and mechanical strength of the cured plate. Table 2 below shows the experimental data on the effect of different humidity environments on the conversion of PbO to 4BS.

[0032] Table 2 PbO conversion rate, PbSO 4 Generation analysis humidity(%) 4BS content (%) <![CDATA[PbSO 4 Content]]> PbO residue (%) 85 52.3 24.5 23.2 90 65.1 19.2 15.7 95 78.4 12.1 9.5 98 80.1 10.3 9.6 In Table 2, at 85% humidity, the conversion rate of PbO is low, and PbSO 4 The formation amount is high, reaching 24.5%, indicating that low humidity can easily lead to PbO directly reacting with sulfuric acid to form PbSO 4 , rather than 4BS; as the humidity increases to 95%, the conversion rate of PbO increases significantly to 78.4%, while that of PbSO 4 The content of PbSO decreased to 12.1%, indicating that higher humidity helps to inhibit 4 The formation of PbO preferentially converts to 4BS; at 98% humidity, the content of 4BS (80.1%) is basically stable, and the residual PbO is low (9.6%), indicating that when the humidity is too high, the conversion efficiency is close to saturation, which will not significantly increase the proportion of 4BS, but is still beneficial to inhibit the formation of PbSO 4 formation.

[0033] Table 3 below shows the conductivity of lead-acid battery plates in different humidity environments.

[0034] Table 3 Electrode conductivity analysis humidity(%) Conductivity (mS cm⁻¹) 85 2.8 90 3.4 95 4.2 98 4.3 Table 3 shows that at 85% humidity, the conductivity of the plate is the lowest (2.8 mS cm⁻¹), which may be due to the presence of more PbSO 4The formation of 4BS hinders the transmission of electrons and ions; at 95% humidity, the conductivity reaches 4.2 mS·cm⁻¹, indicating that high humidity promotes the formation of 4BS and improves the conductivity of the plate; the conductivity at 98% humidity is not much different from that at 95%, indicating that after the humidity exceeds 95%, the improvement of conductivity tends to saturation.

[0035] Table 4 below shows the mechanical strength of lead-acid battery plates in different humidity environments.

[0036] Table 4 Mechanical strength analysis of the plate humidity(%) Flexural strength(MPa) 85 4.5 90 5.8 95 7.3 98 7.4 Table 4 shows that at 85% humidity, the flexural strength of the plate is low (4.5 MPa), which may be due to the PbSO 4 A higher ratio results in a more fragile plate structure; at 95% humidity, the flexural strength is the highest (7.3 MPa), which indicates that the formation of 4BS enhances the mechanical stability of the plate; at 98% humidity, the flexural strength does not change much (7.4 MPa), and further increasing the humidity has limited contribution to the mechanical strength of the plate.

[0037] In order to speed up the evaporation of water and prevent the plate surface from drying out too quickly and causing cracks that affect the curing quality, a ventilation control strategy needs to be adopted, including the following specific steps: Step Z1: deploy humidity sensors in the curing room. Assume that the curing room is divided into N areas. The humidity value of each area is measured by the humidity sensor to obtain the humidity value of each area at time t. : ,in, represents the humidity value at time t in the first area, represents the humidity value at time t in the second area, Represents the humidity value at time t in the Nth region; and calculates the global average humidity value : , Indicates the curing room Regions, For the The humidity value in the area at time t; then the humidity gradient value The calculation formula is: ,like , it means that the humidity in the curing room has reached a balanced state, and there is no need to adjust the wind speed and direction. To set the threshold; if , then go to the next step to adjust the wind speed and direction.

[0038] Step Z2, construct a wind speed adjustment model to control the wind speed adjustment amount so that it can dynamically respond to changes in humidity in the curing room to avoid uneven curing effects caused by too fast or too slow adjustment. The calculation formula of the wind speed adjustment model is: ,in, For the The wind speed adjustment in a region at time t; For the Time in the region The wind speed adjustment at the moment; It is a proportional control item, reflecting the impact of the current humidity deviation on the wind speed; is the integral control term; Indicates that from the initial moment All historical time steps between now and the current time t; Describe the first Regions in historical time Humidity measurement value at the moment; Indicates historical time The average humidity value in the curing room at the moment; T represents the sampling interval; is the differential control term; is an adaptive adjustment factor used to adjust the dynamic changes of wind speed. In addition, the wind speed limit is increased to ensure that the wind speed does not exceed the physical safety range: , is the preset minimum allowable wind speed value, It is the preset maximum allowed wind speed value.

[0039] Step Z3, in order to optimize the air flow path and reduce the local humidity DC, define the wind direction angle adjustment rules: ,in, is the wind direction angle, representing the direction of air flow; Indicates the curing room The wind direction angle of a region at time t; Indicates the curing room Regions in time The wind direction at the moment; Adjust the gain for wind direction and control the sensitivity of wind direction changes; Beyond 0°-180°, adjust the limit: .

[0040] Step Z4, using closed-loop control, recalculate wind speed and direction at every time interval T, and perform the following iterations: 1. Calculate humidity gradient ; 2. Calculate the wind speed adjustment And update the wind speed; 3. Calculate the wind direction adjustment And update the wind direction; 4. Enter the next time step , and continue the cycle.

[0041] See also Figure 5 As shown in the graph, after adopting the optimized ventilation strategy, the water evaporation rate increased by about 30%, allowing the water to diffuse more evenly from the inside of the plate to the outside, accelerating the evaporation of water and reducing the drying time.

[0042] In step S3, temperature-controlled drying technology is used to reduce the moisture content to below 0.1%, ensuring that the plate is completely dried without cracks, including: The temperature-controlled drying technology includes three stages: pre-drying stage, medium-temperature diffusion drying stage and uniform drying stage, to ensure that the moisture of the plate is evenly discharged during the drying process, and to avoid structural damage caused by too rapid temperature rise. In the pre-drying stage (0-8 hours), the plate is placed in a drying room with high humidity (>35%RH) and low temperature (40-50°C). The main purpose of this stage is to promote the diffusion of moisture from the inside of the plate to the outside through capillary action, while reducing the moisture gradient inside the plate, and avoiding the surface moisture from evaporating too quickly and causing the surface layer to harden. In the medium-temperature diffusion drying stage (8-24 hours), the drying temperature is gradually increased to 60-70°C, and the humidity is reduced to 15-25%RH. The goal of this stage is to accelerate the diffusion and dehydration process of moisture. In order to further optimize the moisture diffusion rate, an intermittent heating strategy is adopted, that is, the temperature is increased by 5°C every 2-4 hours, and the humidity is simultaneously reduced by 5%, so that the dehydration rate is consistent with the moisture diffusion rate. During the uniform drying stage (24-32 hours), the drying temperature is controlled at 75-80°C, the humidity is reduced to 5-10%RH, and the evaporation of water is accelerated through the air convection system. At this time, the moisture content of the plate has dropped to about 1.0%, but further drying is still required to ensure that the moisture content drops below 0.1%. In this stage, the wind speed is first increased to 1.5-2.0m / s to accelerate the evaporation of water, and then the wind speed is gradually reduced to 0.8m / s in the last 4 hours to avoid the formation of surface cracks due to excessive wind force. In addition, to ensure uniform temperature, infrared thermal imaging monitoring technology is also used in the drying process to monitor the temperature distribution on the surface of the plate in real time, and when the local temperature deviation is found to exceed ±2°C, the position of the heating element or the air flow direction is adjusted to ensure uniform heating of the plate, further reduce thermal stress, and prevent the formation of microcracks.

[0043] In the initial stage, the present invention accelerates the transformation of lead oxide into tribasic lead sulfate crystal phase through specific temperature and humidity conditions (humidity above 95% and temperature of 42-50°C), reduces the free lead content, improves the curing efficiency, and can complete the curing of this stage in a shorter time than the traditional process. In the process of heating to 65°C and maintaining high humidity, not only the formation of tetrabasic lead sulfate crystal phase is promoted, the conductivity and mechanical strength of the plate are improved, but also the wind speed and wind direction are dynamically adjusted according to the humidity gradient value by optimizing the ventilation control strategy, the evaporation of water is accelerated and the drying time is reduced, and the evaporation rate of water is increased by about 30%. The final temperature-controlled drying technology adopts three stages of pre-drying, medium-temperature diffusion drying and uniform drying to control temperature, humidity and air flow, avoid cracks caused by excessive drying of the plate, and ensure uniform discharge of water. The present invention significantly shortens the curing time of the lead-acid battery plate, improves the stability of the plate, enhances the mechanical strength and cycle life of the plate, and thus prolongs the service life of the battery.

[0044] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A curing process for battery plates, characterized in that: The steps include: Step S1, using a humidity of more than 95% and a temperature of 42-50° C. to reduce the free lead content of the lead paste to less than 14%, thereby promoting the conversion of lead oxide into a tribasic lead sulfate crystal phase; Step S2, raising the curing temperature to 65° C., maintaining a humidity of 95% to promote the formation of a tetrabasic lead sulfate crystal phase, and adopting a ventilation control strategy to accelerate water evaporation and reduce drying time; Step S3, using temperature-controlled drying technology to reduce the moisture content to below 0.1%, ensuring that the plate is completely dry without cracks; The ventilation control strategy includes the following specific steps: Step Z1: Deploy humidity sensors in the curing room to calculate the global average humidity value ; Step Z2, construct a wind speed adjustment model to control the wind speed adjustment amount, and the calculation formula is: ,in, For the The wind speed adjustment amount in a region at time t; For the Time in the region The wind speed adjustment at the moment; is the proportional control term; For the Humidity value in each area at time t; is the integral control term; represents the historical time step; Describe the first Regions in historical time Humidity measurement value at the moment; Indicates historical time The average humidity value in the curing room at the moment; T represents the sampling interval; is the differential control term; is the adaptive adjustment factor; Step Z3, in order to optimize the air flow path and reduce the local humidity DC, define the adjustment rules of the wind direction angle.

2. A curing process for battery plates according to claim 1, characterized in that , the global average humidity value The calculation formula is: , Indicates the curing room Regions, For the The humidity value in the area at time t; then the humidity gradient value The calculation formula is: .

3. A curing process for battery plates according to claim 1, characterized in that , the adjustment rule of the wind direction angle is: ,in, is the wind direction angle, representing the direction of air flow; Indicates the curing room The wind direction angle of a region at time t; Indicates the curing room Regions in time The wind direction at the moment; Adjust the gain for wind direction and control the sensitivity of wind direction changes; Beyond 0°-180°, adjust the limit: .

4. A curing process for a battery plate according to claim 1, characterized in that: In step S1, the humidity of the lead paste is between 10-14%, the freshly coated lead paste plates are arranged on a metal bracket, the temperature in the curing chamber is set at 42-50° C., and the humidity in the curing chamber is set at above 95% by a water spray humidification system.

5. A curing process for a battery plate according to claim 1, characterized in that: In the step S1, under the conditions of humidity above 95% and temperature of 42-50° C., lead oxide first combines with water to form lead hydroxide, and then is converted into tribasic lead sulfate under the action of sulfuric acid vapor. Within 8 hours before curing, the proportion of tribasic lead sulfate crystal phase formation reaches more than 85%, and the free lead content is reduced from 22-25% to less than 14%.

6. A curing process for a battery plate according to claim 1, characterized in that: In step S2, the temperature of the curing chamber is gradually increased from 42-50° C. to 65° C. within 4-6 hours, and the humidity is maintained above 95%.

7. A curing process for a battery plate according to claim 1, characterized in that: In step S3, the temperature-controlled drying technology includes a pre-drying stage, a medium-temperature diffusion drying stage and a uniform drying stage.

8. A curing process for a battery plate according to claim 7, characterized in that: In the pre-drying stage, the electrode plate is placed in a drying chamber with a humidity greater than 35% RH and a temperature of 40-50°C, and the capillary action promotes the diffusion of moisture from the inside of the electrode plate to the outside; in the medium-temperature diffusion drying stage, the drying temperature is gradually increased to 60-70°C, the humidity is reduced to 15-25%RH, and an intermittent heating strategy is adopted to increase the temperature by 5°C and simultaneously reduce the humidity by 5% every 2-4 hours; in the uniform drying stage, the drying temperature is controlled at 75-80°C, the humidity is reduced to 5-10%RH, the wind speed is first increased to 1.5-2.0m / s, and then gradually reduced to 0.8m / s within the last 4 hours.

9. A curing process for a battery plate according to claim 7, characterized in that: The uniform drying stage uses infrared thermal imaging monitoring technology to monitor the temperature distribution on the plate surface in real time. When the local temperature deviation exceeds ±2°C, the heating element position or air flow direction is adjusted.

Images