Negative pressure and positive pressure combined acid adding process for 2V lead-acid storage battery

Abstract

The invention relates to the technical field of lead-acid storage battery manufacturing, and discloses a 2V lead-acid storage battery negative pressure and positive pressure combined acid adding process which comprises the following steps: S1, acid adding; s2, quantifying; s3, adding acid; s4, vacuumizing for the first time; s5, injecting acid; s6, vacuumizing for the second time; s7, performing positive pressure treatment; through combined application of negative pressure and positive pressure, the electrolyte permeation effect is improved, the formation time is shortened, the energy consumption is reduced, the consistency and matching rate of the battery are improved, bubbles in a polar plate are more thoroughly eliminated by adopting double vacuumizing, the electrolyte permeation uniformity is improved by adopting positive pressure treatment, the performance of the battery is improved, and the battery quality is improved. The distribution uniformity of acid liquor on the section of a pole plate of the battery is improved by more than or equal to 15%, the density of an active substance is improved by 10-15%, the product consistency is improved by more than or equal to 12%, the capacity consistency is improved by 15-20%, the internal resistance consistency is improved by 12-15%, the battery matching rate is improved by 18-22%, the formation time is shortened by 15-25%, and the energy consumption is reduced by 15-20%.

Description

Technical Field

[0001] The invention relates to the technical field of lead-acid battery manufacturing, in particular to a negative-positive pressure combined acid-adding process for a 2V lead-acid battery. Background Art

[0002] The manufacturing of lead-acid batteries is a complex and delicate process, which mainly includes key steps such as lead powder manufacturing, grid casting, plate manufacturing, plate formation and battery assembly. The manufacturing process of lead-acid batteries is a complex and delicate system engineering, which requires strict control of process parameters and quality requirements in each link.

[0003] During the production process of lead-acid batteries, the quality of the acid adding process directly affects the performance of the battery.

[0004] After searching, the patent with application number CN202111184836.8 discloses a segmented acid-adding process for lead-acid batteries, which relates to the field of battery production technology. The invention includes step 1: placing an acid-adding pot; step 2: adding acid once, and the amount of acid added once is 30% to 40% of the total amount of acid added; step 3: vacuuming once; step 4: adding acid twice, and the amount of acid added twice is 30% to 40% of the total amount of acid added; step 5: vacuuming twice; step 6: adding acid three times, and the amount of acid added three times is 30% to 40% of the total amount of acid added; step 7: vacuuming three times; step 8: extracting residual acid from the acid-adding pot after vacuuming three times, or replenishing acid liquid, and charging the battery after completion. The invention adds acid and vacuumizes the battery three times by segmented acid-adding, which solves the problem that the existing one-time acid-adding easily leads to incomplete wetting of the center of the plate, affecting the overall performance of the battery. At the same time, due to the small amount of acid added each time, the vacuuming time is greatly reduced, which is conducive to improving the overall production efficiency.

[0005] In the prior art, the negative pressure acid addition process is generally used in lead-acid battery manufacturing, that is, the electrolyte is infiltrated into the plate by vacuuming. This single negative pressure acid addition method has the following defects:

[0006] 1. Bubbles may remain inside the plate, affecting the utilization of active substances;

[0007] 2. Uneven electrolyte penetration leads to large differences in the degree of plate penetration;

[0008] 3. Especially for medium and large-sized lead-acid batteries, due to the thick plates, the formation time is long and the energy consumption is high under the traditional process;

[0009] Therefore, we need to propose a negative and positive pressure combined acid adding process for 2V lead-acid batteries. Through the combined application of negative and positive pressure, the electrolyte penetration effect can be improved, the formation time can be shortened, the energy consumption can be reduced, and the battery consistency and matching rate can be improved. Summary of the invention

[0010] The purpose of the present invention is to provide a 2V lead-acid battery negative and positive pressure combined acid addition process, through the combined application of negative pressure and positive pressure, the electrolyte penetration effect is improved, the formation time is shortened, the energy consumption is reduced, the battery consistency and the assembly rate are improved, so as to solve the problems raised in the above background technology.

[0011] To achieve the above object, the present invention provides the following technical solution: a 2V lead-acid battery negative-positive pressure combined acid addition process, comprising the following steps:

[0012] S1. Acid addition: add a predetermined amount of electrolyte into the battery casing using an acid adding device for a duration of ≥15 seconds;

[0013] S2. Quantitative measurement: real-time monitoring and recording of the amount of electrolyte added, and after the acid addition is completed, measuring the electrolyte level to ensure that the amount of electrolyte added to each battery is consistent, and the duration is ≥10 seconds;

[0014] S3, acid addition: After adding a certain amount of electrolyte, place the battery at an angle or shake the battery slowly and evenly to allow the electrolyte to evenly cover the plates, and the duration should be ≥20 seconds;

[0015] S4. First vacuuming: Use a vacuum pump and a precision pressure sensor to vacuum the battery, reduce the internal pressure of the battery to a negative pressure value of ≤-85kPa, and last for ≥15 seconds to remove bubbles inside the battery;

[0016] S5, acid injection: after the first vacuuming, the electrolyte is replenished to a predetermined level according to the loss of electrolyte inside the battery, and the duration is ≥15 seconds;

[0017] S6. Second vacuuming: The battery is vacuumed again by using a vacuum pump in conjunction with a precision pressure sensor to reduce the internal pressure of the battery to a negative pressure value of ≤-85 kPa for a duration of ≥15 seconds, further removing the bubbles inside the battery to ensure that the electrolyte completely infiltrates the plates;

[0018] S7, positive pressure treatment: After the second vacuuming, nitrogen is introduced into the battery through the positive pressure gas source and the pressure regulating valve to raise the internal pressure of the battery to a positive pressure value of 25-35 kPa, which lasts for 15-20 seconds.

[0019] Preferably, in step S1, the acid adding equipment uses a quantitative acid adding pump, the quantitative acid adding pump is connected to the electrolyte tank, the electrolyte is dilute sulfuric acid, when the acid is added, the quantitative acid adding pump is started, and the electrolyte is slowly injected from the electrolyte tank into the battery housing, so that the electrolyte is evenly distributed between the plates.

[0020] Preferably, in step S2, a liquid level monitor is used to connect the drain port or the liquid filling port of the battery housing, and the liquid level of the electrolyte added is determined by observing the liquid level monitor. If the electrolyte level deviates from the set value, the flow rate of the quantitative acid adding pump is adjusted to ensure that the amount of electrolyte added is accurate.

[0021] Preferably, in step S3, when the battery needs to be tilted, the battery is placed on a bracket or tilting table with an adjustable angle so that the electrolyte can flow naturally and evenly cover the plates. After the electrolyte is evenly distributed, the battery is left to stand for no less than 20 seconds to allow the battery to fully soak the plates and reach a stable state.

[0022] Preferably, in step S4, the maximum negative pressure value of the vacuum pump is -90 kPa, and the precision pressure sensor is used to measure the negative pressure value inside the battery, and can monitor and adjust the internal pressure of the battery in real time.

[0023] Preferably, in step S4, when vacuuming for the first time, the inside of the battery housing is connected to the vacuum pump through pipes and valves, and then the vacuum pump is operated to start evacuating air, and the reading of the precision pressure sensor is observed until the internal pressure of the battery gradually decreases to -90kPa to -85kPa, and the vacuum pump is kept running, so that the internal pressure of the battery remains stable for not less than 15 seconds, and finally the vacuum pump is turned off.

[0024] Preferably, in step S5, before acid injection, observe the transparent window of the battery housing or evaluate the electrolyte loss through a liquid level monitor, and reconnect the quantitative acid adding pump to the battery, adjust the quantitative acid adding pump, inject the supplementary electrolyte into the battery, and control the injection speed until the liquid level of the electrolyte rises to a predetermined level, and then stop and remove the quantitative acid adding pump.

[0025] Preferably, in step S6, when vacuuming for the second time, the vacuum pump is connected again, the vacuum pump is operated to start pumping air, and the reading of the precision pressure sensor is observed until the internal pressure of the battery gradually decreases to -90kPa to -85kPa, and the vacuum pump is kept running to keep the internal pressure of the battery stable for not less than 15 seconds to ensure that the electrolyte completely infiltrates the plates.

[0026] Preferably, in step S7, the air pressure value of the positive pressure air source can be adjusted within the range of 0-50 kPa.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention improves the electrolyte penetration effect, shortens the formation time, reduces energy consumption, and improves battery consistency and assembly rate through the combined application of negative pressure and positive pressure.

[0029] 2. The present invention adopts double vacuuming to more thoroughly remove bubbles inside the plate, adopts positive pressure treatment to improve the uniformity of electrolyte penetration, and the process parameters are precisely controllable.

[0030] 3. The negative and positive pressure combined acid adding process of the present invention improves the performance of the battery, and improves the uniformity of acid distribution on the cross section of the battery plate by ≥15%, the density of the active material by 10-15%, the product consistency by ≥12%, the capacity consistency by 15-20%, the internal resistance consistency by 12-15%, the battery assembly rate by 18-22%, the formation time by 15-25%, and the energy consumption by 15-20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flowchart of the present invention. DETAILED DESCRIPTION

[0032] 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.

[0033] Example 1

[0034] See also Figure 1 The present invention provides a technical solution: a 2V lead-acid battery negative-positive pressure combined acid-adding process, comprising the following steps:

[0035] S1. Acid addition: Use acid adding equipment to add a predetermined amount of electrolyte into the battery shell for a duration of ≥15 seconds; the temperature of the electrolyte is controlled at 20-30°C, and the temperature of the electrolyte is monitored in real time to reduce the impact of temperature fluctuations on battery performance and ensure the stability and controllability of the acid adding process.

[0036] In step S1, the acid adding equipment uses a quantitative acid adding pump, which is connected to an electrolyte tank. The electrolyte uses dilute sulfuric acid. When adding acid, the quantitative acid adding pump is started to slowly inject the electrolyte from the electrolyte tank into the battery housing so that the electrolyte is evenly distributed between the plates.

[0037] Before acid treatment, the battery needs to be pretreated: Use deionized water or a special cleaning agent to thoroughly clean the battery shell to remove surface oil and impurities. Place the cleaned battery shell in a drying device to remove moisture by heating or natural air drying to ensure internal dryness. Assemble the plates, separators and other internal components correctly in the battery shell according to design requirements.

[0038] Make sure there is dilute sulfuric acid in the electrolyte tank and check whether the battery casing is well sealed and has no damage or leakage.

[0039] Connect the outlet pipe of the quantitative acid adding pump to the filling port of the battery shell, open the acid adding valve, and slowly inject the electrolyte into the battery shell. Pay attention to controlling the injection speed to avoid splashing of electrolyte or a sharp increase in the internal pressure of the battery. During the injection process, closely observe the changes in the battery shell to ensure that the electrolyte is evenly distributed between the plates. You can gently shake or tap the battery shell to help the electrolyte better infiltrate the plates.

[0040] During the acid adding process, continuously monitor the flow of the acid adding pump and the electrolyte level in the battery shell. If it is found that the electrolyte injection speed is too fast or the battery shell has abnormal changes, stop acid adding immediately, adjust the flow of the acid adding pump or close the acid adding valve.

[0041] S2. Quantitative measurement: real-time monitoring and recording of the amount of electrolyte added, and after the acid addition is completed, measuring the electrolyte level to ensure that the amount of electrolyte added to each battery is consistent, and the duration is ≥10 seconds;

[0042] In step S2, a liquid level monitor is used to connect the drain port or the liquid filling port of the battery housing, and the liquid level of the electrolyte added is determined by observing the liquid level monitor. If the electrolyte level deviates from the set value, the flow rate of the quantitative acid adding pump is adjusted to ensure that the amount of electrolyte added is accurate.

[0043] S3, acid addition: After adding a certain amount of electrolyte, place the battery at an angle or shake the battery slowly and evenly to allow the electrolyte to evenly cover the plates, and the duration should be ≥20 seconds;

[0044] In step S3, when the battery needs to be tilted, the battery is placed on a bracket or tilting table with an adjustable angle so that the electrolyte can flow naturally and evenly cover the plates. After the electrolyte is evenly distributed, the battery is left to stand for no less than 20 seconds to allow the battery to fully soak the plates and reach a stable state.

[0045] The tilt angle of the battery is determined according to the specific design of the battery and the properties of the electrolyte, so that the electrolyte can flow naturally and evenly cover the plates, avoiding uneven distribution of the electrolyte due to too fast or too slow flow of the electrolyte; during the static period, closely observe the changes in the electrolyte inside the battery to ensure that no abnormalities occur. When adjusting the tilt angle of the battery or shaking the battery, avoid excessive operation that may cause electrolyte splashing or battery damage.

[0046] S4. First vacuuming: Use a vacuum pump and a precision pressure sensor to vacuum the battery, reduce the internal pressure of the battery to a negative pressure value of ≤-85kPa, and last for ≥15 seconds to remove bubbles inside the battery;

[0047] In step S4, the maximum negative pressure value of the vacuum pump is -90 kPa. The precision pressure sensor is used to measure the negative pressure value inside the battery, which can monitor and adjust the internal pressure of the battery in real time and record the pressure curve.

[0048] In step S4, when evacuating the battery for the first time, connect the inside of the battery casing to the vacuum pump through pipes and valves, then run the vacuum pump to start evacuating air, and observe the reading of the precision pressure sensor to ensure that the vacuum pump can gradually reduce the internal pressure of the battery until the internal pressure of the battery gradually drops to -90kPa ~ -85kPa, and keep the vacuum pump running to keep the internal pressure of the battery stable for not less than 15 seconds, which helps to remove bubbles and excess gas inside the battery and ensure that the electrolyte is evenly distributed. Finally, turn off the vacuum pump, slowly open the valve of the connecting pipe, allow the internal pressure of the battery to gradually return to atmospheric pressure, and disconnect the battery from the vacuum system.

[0049] During the vacuuming process, continuously monitor the reading of the pressure sensor to ensure that the internal pressure of the battery gradually decreases to the specified negative pressure value. If it is found that the pressure drops too slowly or the pressure value deviates from the specified range, immediately check the working status of the vacuum pump, the sealing of the connecting pipes and the integrity of the battery casing.

[0050] S5, acid injection: after the first vacuuming, the electrolyte is replenished to a predetermined level according to the loss of electrolyte inside the battery, and the duration is ≥15 seconds;

[0051] In step S5, before acid injection, observe the transparent window of the battery casing or evaluate the electrolyte loss through the liquid level monitor, reconnect the quantitative acid adding pump to the battery, adjust the quantitative acid adding pump, inject the supplementary electrolyte into the battery, and control the injection speed until the electrolyte level rises to a predetermined level, then stop and remove the quantitative acid adding pump.

[0052] If the electrolyte injection speed is found to be too fast or too slow, the flow rate of the acid pump should be adjusted immediately to avoid electrolyte overflow or shortage.

[0053] S6. Second vacuuming: The battery is vacuumed again by using a vacuum pump in conjunction with a precision pressure sensor to reduce the internal pressure of the battery to a negative pressure value of ≤-85 kPa for a duration of ≥15 seconds, further removing the bubbles inside the battery to ensure that the electrolyte completely infiltrates the plates. After the vacuuming is completed, the penetration of the plates is tested;

[0054] In step S6, when vacuuming for the second time, connect the vacuum pump again, run the vacuum pump to start pumping, and observe the reading of the precision pressure sensor until the internal pressure of the battery gradually drops to -90kPa ~ -85kPa, and keep the vacuum pump running to keep the internal pressure of the battery stable for no less than 15 seconds to ensure that the electrolyte completely infiltrates the plates.

[0055] S7, positive pressure treatment: After the second vacuuming, the positive pressure gas source is used in conjunction with the pressure regulating valve to ensure that the gas pressure and flow rate entering the battery can be accurately controlled. Nitrogen is introduced into the battery to raise the internal pressure of the battery to a positive pressure value of 25-35kPa and remain stable for a period of time, lasting 15-20 seconds, which helps to promote further penetration and uniform distribution of the electrolyte.

[0056] In step S7, the air pressure value of the positive pressure air source can be adjusted within the range of 0-50 kPa.

[0057] In this embodiment, when a 2V / 1000Ah lead-acid battery is acidified by a negative-positive pressure combination, the process parameters are as follows:

[0058] The acid application time is 17 seconds;

[0059] The quantitative time is 12 seconds;

[0060] The acid-adding time is 22 seconds;

[0061] The negative pressure value of the first vacuuming was -85 kPa, and the vacuuming time was 17 seconds;

[0062] The acid injection time is 17 seconds;

[0063] The negative pressure value of the second vacuuming is -85kPa, and the vacuuming time is 17 seconds;

[0064] The air pressure during the positive pressure treatment was 30 kPa and the time was 18 seconds.

[0065] Batteries produced using this process: capacity consistency improved by 15-20%, internal resistance consistency improved by 12-15%, and battery assembly rate improved by 18-22%.

[0066] Example 2

[0067] The same as the above embodiment will not be repeated, the difference is

[0068] When performing negative and positive pressure combined acid addition on medium and large dense 2V / 2000Ah lead-acid batteries, the duration of each step can be appropriately extended, and the process parameters are as follows:

[0069] Acid application time: ≥18 seconds;

[0070] Quantification time: ≥12 seconds;

[0071] Acid time: ≥22 seconds;

[0072] The negative pressure value of the first vacuuming is -85kPa, and the vacuuming time is ≥18 seconds;

[0073] Acid injection time: ≥18 seconds;

[0074] The negative pressure value of the second vacuuming is -85kPa, and the vacuuming time is ≥18 seconds;

[0075] The air pressure during positive pressure treatment is 30-35 kPa, and the time is 18-22 seconds.

[0076] This process can shorten the formation time of medium and large dense batteries by 15-25%, and can reduce the formation energy consumption of medium and large dense batteries by 15-20%.

[0077] The effect verification of the acid addition process of the present embodiment is as follows:

[0078] The uniformity of acid distribution on the plate cross section is improved by ≥15%;

[0079] The density of active substances is increased by 10-15%;

[0080] The energy consumption of chemical formation is reduced by 15-20%;

[0081] Product consistency improved by ≥12%.

[0082] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A 2V lead-acid battery negative and positive pressure combined acid addition process, characterized in that: The steps include: S1. Acid addition: add a predetermined amount of electrolyte into the battery casing using an acid adding device for a duration of ≥15 seconds; S2. Quantitative measurement: real-time monitoring and recording of the amount of electrolyte added, and after the acid addition is completed, measuring the electrolyte level to ensure that the amount of electrolyte added to each battery is consistent, and the duration is ≥10 seconds; S3, acid addition: After adding a certain amount of electrolyte, place the battery at an angle or shake the battery slowly and evenly to allow the electrolyte to evenly cover the plates, and the duration should be ≥20 seconds; S4. First vacuuming: Use a vacuum pump and a precision pressure sensor to vacuum the battery, reduce the internal pressure of the battery to a negative pressure value of ≤-85kPa, and last for ≥15 seconds to remove bubbles inside the battery; S5, acid injection: after the first vacuuming, the electrolyte is replenished to a predetermined level according to the loss of electrolyte inside the battery, and the duration is ≥15 seconds; S6. Second vacuuming: The battery is vacuumed again by using a vacuum pump in conjunction with a precision pressure sensor to reduce the internal pressure of the battery to a negative pressure value of ≤-85 kPa for a duration of ≥15 seconds, further removing the bubbles inside the battery to ensure that the electrolyte completely infiltrates the plates; S7, positive pressure treatment: After the second vacuuming, nitrogen is introduced into the battery through the positive pressure gas source and the pressure regulating valve to raise the internal pressure of the battery to a positive pressure value of 25-35 kPa, which lasts for 15-20 seconds.

2. A 2V lead-acid battery negative and positive pressure combined acid addition process according to claim 1, characterized in that: In step S1, the acid adding equipment uses a quantitative acid adding pump, which is connected to an electrolyte tank. The electrolyte uses dilute sulfuric acid. When adding acid, the quantitative acid adding pump is started to slowly inject the electrolyte from the electrolyte tank into the battery housing so that the electrolyte is evenly distributed between the plates.

3. A 2V lead-acid battery negative and positive pressure combined acid addition process according to claim 1, characterized in that: In step S2, a liquid level monitor is used to connect the drain port or the liquid filling port of the battery housing, and the liquid level of the electrolyte added is determined by observing the liquid level monitor. If the electrolyte level deviates from the set value, the flow rate of the quantitative acid adding pump is adjusted to ensure that the amount of electrolyte added is accurate.

4. A 2V lead-acid battery negative and positive pressure combined acid addition process according to claim 1, characterized in that: In step S3, when the battery needs to be tilted, the battery is placed on a bracket or tilting table with an adjustable angle so that the electrolyte can flow naturally and evenly cover the plates. After the electrolyte is evenly distributed, the battery is left to stand for no less than 20 seconds to allow the battery to fully soak the plates and reach a stable state.

5. A 2V lead-acid battery negative and positive pressure combined acid addition process according to claim 1, characterized in that: In step S4, the maximum negative pressure value of the vacuum pump is -90 kPa, and the precision pressure sensor is used to measure the negative pressure value inside the battery, which can monitor and adjust the internal pressure of the battery in real time.

6. A 2V lead-acid battery negative-positive pressure combined acid addition process according to claim 5, characterized in that: In step S4, when vacuuming for the first time, connect the inside of the battery casing to the vacuum pump through pipes and valves, then run the vacuum pump to start evacuating air, and observe the reading of the precision pressure sensor until the internal pressure of the battery gradually drops to -90kPa ~ -85kPa, and keep the vacuum pump running, so that the internal pressure of the battery remains stable for not less than 15 seconds, and finally turn off the vacuum pump.

7. A 2V lead-acid battery negative and positive pressure combined acid addition process according to claim 1, characterized in that: In step S5, before acid injection, observe the transparent window of the battery casing or evaluate the electrolyte loss through the liquid level monitor, reconnect the quantitative acid adding pump to the battery, adjust the quantitative acid adding pump, inject the supplementary electrolyte into the battery, and control the injection speed until the electrolyte level rises to a predetermined level, then stop and remove the quantitative acid adding pump.

8. A 2V lead-acid battery negative and positive pressure combined acid addition process according to claim 1, characterized in that: In step S6, when vacuuming for the second time, connect the vacuum pump again, run the vacuum pump to start pumping, and observe the reading of the precision pressure sensor until the internal pressure of the battery gradually drops to -90kPa ~ -85kPa, and keep the vacuum pump running to keep the internal pressure of the battery stable for no less than 15 seconds to ensure that the electrolyte completely infiltrates the plates.

9. A 2V lead-acid battery negative and positive pressure combined acid addition process according to claim 1, characterized in that: In step S7, the air pressure value of the positive pressure air source can be adjusted within the range of 0-50 kPa.

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