Vacuum formation process and device for lead-acid storage battery

Abstract

The invention belongs to the technical field of lead-acid storage battery manufacturing, and particularly discloses a lead-acid storage battery vacuum formation process and a device thereof.The assembled battery is placed in the vacuum formation device to be pretreated, electrolyte with the preset temperature is injected into the battery under the vacuum condition, and then on the premise that the vacuum state is kept, the lead-acid storage battery is formed. The method comprises the following steps: carrying out segmented constant-current charging on a battery, carrying out degassing treatment on the battery by utilizing a vacuum system of a vacuum formation device after formation is completed, checking and adjusting the liquid level of electrolyte in the battery after degassing treatment, carrying out sealing treatment on the battery after liquid level adjustment is completed, and injecting the electrolyte under a vacuum condition, so that the interference of air and bubbles is reduced; the electrolyte can more quickly and uniformly permeate into the polar plate, so that the formation reaction can be more efficiently carried out, and the segmented constant-current formation mode is also beneficial to more reasonable control of the reaction process, improvement of the conversion efficiency of the active substance and shortening of the formation time.

Description

Technical Field

[0001] The present invention belongs to the technical field of lead-acid battery manufacturing, and particularly relates to a vacuum forming process and device for lead-acid batteries. Background Art

[0002] During the forming process of lead-acid batteries, a large amount of hydrogen and oxygen are generated on the surface of the electrode plates. These gases will form a gas film that hinders the full contact between the electrolyte and the electrode plates, reducing the forming efficiency. Traditional forming processes mainly rely on natural exhaust or mechanical stirring to handle these gases. Natural exhaust is to allow the generated gases to escape naturally through the openings or ventilation holes in the battery case, and mechanical stirring is to stir the electrolyte through a mechanical device to increase the fluidity and diffusivity of the electrolyte, thereby accelerating the discharge of gases.

[0003] However, when using the above traditional forming methods for lead-acid batteries, due to the limitations of natural exhaust and mechanical stirring, the gases generated during the forming process are difficult to discharge in a timely manner, resulting in an extended forming time, insufficient contact between the electrode plates and the electrolyte, and low utilization rate of active substances. Therefore, we need to propose a vacuum forming process and device for lead-acid batteries to solve the above existing problems, enabling it to quickly evacuate the gases generated on the surface of the electrode plates by applying a vacuum environment during the forming process, improving the contact efficiency between the electrolyte and the electrode plates, accelerating the forming speed, and increasing the utilization rate of active substances on the electrode plates. Summary of the Invention

[0004] The purpose of the present invention is to provide a vacuum forming process and device for lead-acid batteries, which can quickly evacuate the gases generated on the surface of the electrode plates by applying a vacuum environment during the forming process, improve the contact efficiency between the electrolyte and the electrode plates, accelerate the forming speed, and increase the utilization rate of active substances on the electrode plates, so as to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A vacuum forming process for lead-acid batteries includes the following steps:

[0007] S1. Place the assembled battery in a vacuum forming device for pretreatment;

[0008] S2. Inject the electrolyte with a preset temperature into the battery under vacuum conditions;

[0009] S3. Perform segmented constant current charging on the battery while maintaining the vacuum state;

[0010] S4. Confirm whether the battery forming is completed. If not, return to S3; if completed, enter S5;

[0011] S5. Degas the battery using the vacuum system of the vacuum formation device;

[0012] S6. After degassing, check and adjust the liquid level of the electrolyte in the battery. After the liquid level adjustment is completed, seal the battery.

[0013] Preferably, in step S1, the content of the pretreatment of the battery by the vacuum formation device includes evacuating the battery and preheating the battery. The vacuum degree during evacuation is -0.06 MPa to -0.08 MPa, and the pretreatment time is 15 - 20 minutes.

[0014] Preferably, in step S3, the segmented constant current charging includes an activation stage, a conversion stage, and a completion stage. Among them, the current density in the activation stage is 0.8 - 1.2 mA / cm², and the time is 2 - 3 hours; the current density in the conversion stage is 1.5 - 2.0 mA / cm², and the time is 3 - 4 hours; the current density in the completion stage is 2.0 - 2.5 mA / cm², and the time lasts until the formation is completed.

[0015] Preferably, in step S6, the adjusted liquid level of the electrolyte is at 10 ± 1 mm from the upper end of the electrode plate, and the adjusted electrolyte density is 1.280 ± 0.005 g / cm³.

[0016] Based on the above-described lead-acid battery vacuum formation process, the present invention also provides a device for the lead-acid battery vacuum formation process, including a vacuum formation device. The vacuum formation device includes a tooling table for placing the battery, a vacuum formation cover that can be covered above the battery, and a control system. A sealing ring is provided around the vacuum formation cover. After the vacuum formation cover and the tooling table are combined, a vacuum cavity is formed to place the battery in a vacuum environment. A vacuum pump system is connected to the vacuum formation cover. A vacuum degree detection device is provided on the vacuum pump system. The control system is electrically connected to the vacuum degree detection device and the vacuum pump system respectively.

[0017] Preferably, the vacuum pump system includes a vacuum pump, a vacuum buffer tank, a vacuum pipeline, and a vacuum control valve. The air extraction end of the vacuum pump is connected to the vacuum buffer tank. The air inlet of the vacuum buffer tank is connected to the vacuum formation cover through the vacuum pipeline. The vacuum control valve is installed on the vacuum pipeline.

[0018] Preferably, the vacuum degree detection device is set as a vacuum gauge and a pressure transmitter. The control system includes a PLC controller. The vacuum gauge and the pressure transmitter are both electrically connected to the PLC controller.

[0019] Preferably, the vacuum forming device further includes a temperature control system, which includes a temperature sensor and a heating device located in the vacuum chamber. One end of the temperature sensor is electrically connected to a temperature controller, and both the temperature controller and the heating device are connected to the PLC controller.

[0020] Preferably, the vacuum forming device further includes an electrolyte circulation system, which includes a circulation pump, a heat exchanger, a filter, and a liquid level controller. The inlet end of the circulation pump is connected to the outlet end of the filter, the outlet end of the circulation pump is connected to the inlet end of the heat exchanger, the outlet end of the heat exchanger is connected to the electrolyte inlet of the battery, the electrolyte outlet of the battery is connected to the inlet end of the filter, and the liquid level controller is installed at the upper end of the battery plate.

[0021] Preferably, the vacuum forming device further includes a forming power supply system, which includes a programmable DC power supply, a current detection device, and a data acquisition system. The data acquisition system is electrically connected to the programmable DC power supply and the current detection device respectively.

[0022] A lead-acid battery vacuum forming process and device proposed by the present invention have the following advantages compared with the prior art:

[0023] 1. In the present invention, the assembled battery is placed in a vacuum forming device for pretreatment, then the electrolyte with a preset temperature is injected into the battery under vacuum conditions, and then the battery is charged with constant current in segments while maintaining the vacuum state. After the forming is completed, the battery is degassed by the vacuum system of the vacuum forming device. After the degassing treatment, the liquid level of the electrolyte in the battery is checked and adjusted. After the liquid level adjustment is completed, the battery is sealed. By injecting the electrolyte under vacuum conditions, the interference of air and bubbles is reduced, and the electrolyte can penetrate into the electrode plate more quickly and evenly, so that the forming reaction can proceed more efficiently. The method of constant current forming in segments also helps to more reasonably control the reaction process, improve the conversion efficiency of active substances, shorten the forming time, and thus improve the production efficiency.

[0024] 2. Through the setting of the vacuum forming device, the present invention can make the battery form in a vacuum environment, reduce the content of gases such as oxygen, reduce the possible side reactions between lead and oxygen in the battery, help improve the generation quality and utilization rate of active substances on the battery electrode plate, make the charge and discharge performance of the battery more stable, and extend the service life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow block diagram of the forming process of the present invention;

[0026] Figure 2 is a system block diagram of the vacuum forming device of the present invention;

[0027] Figure 3 This is the operation steps and result graph of the actual battery vacuum formation operation according to the method provided by Embodiment 1 of the present invention. Detailed implementation manners

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0029] Embodiment 1

[0030] The present invention provides a lead-acid battery vacuum formation process as shown in Figure 1 which includes the following steps:

[0031] S1. Place the assembled battery in a vacuum formation device for pretreatment;

[0032] The content of the pretreatment of the battery by the vacuum formation device includes evacuating the battery and preheating the battery. The vacuum degree during evacuation is -0.06 MPa to -0.08 MPa, and the pretreatment time is 15 - 20 minutes.

[0033] S2. Inject the electrolyte with a preset temperature into the battery under vacuum conditions;

[0034] Controlling the temperature of the electrolyte is because the temperature will affect the density, viscosity, and the rate of electrochemical reactions of the electrolyte. Set a suitable temperature according to the actual formation requirements. A suitable temperature can make the electrolyte better penetrate into the active substances of the electrode plate and help the subsequent formation reaction proceed smoothly. The existence of a vacuum environment can reduce the possibility of air being mixed into the electrolyte during the injection process and avoid the formation of bubbles inside the battery.

[0035] S3. Perform segmented constant current charging on the battery while maintaining the vacuum state;

[0036] The segmented constant-current charging includes an activation stage, a conversion stage, and a completion stage. The current density in the activation stage is 0.8 - 1.2 mA / cm², and the time is 2 - 3 hours; the current density in the conversion stage is 1.5 - 2.0 mA / cm², and the time is 3 - 4 hours; the current density in the completion stage is 2.0 - 2.5 mA / cm², and the time lasts until formation is completed. The entire formation process is divided into multiple stages, and different constant current values are used for charging in each stage. In this way, the electrochemical reaction process inside the battery can be controlled more precisely, enabling the active substances on the electrode plates to be gradually and fully converted, improving the quality and efficiency of formation. The current magnitude and duration of different stages will be reasonably set according to factors such as the battery specifications and electrode plate materials.

[0037] S4. Confirm whether the battery formation is completed. If not, return to S3; if completed, proceed to S5.

[0038] S5. Use the vacuum system of the vacuum formation device to degas the battery.

[0039] During the formation process, gases such as hydrogen and oxygen are generated inside the battery. If these gases remain inside the battery, they will affect the performance and lifespan of the battery. Vacuum degassing can effectively remove these gases, reducing the gas content inside the battery to a relatively low level, improving the safety and stability of the battery.

[0040] S6. After degassing treatment, check and adjust the liquid level of the electrolyte inside the battery. After the liquid level adjustment is completed, seal the battery.

[0041] The adjusted liquid level of the electrolyte is at 10 ± 1 mm from the upper end of the electrode plate, and the adjusted electrolyte density is 1.280 ± 0.005 g / cm³. If the liquid level is too high, it may cause the electrolyte to overflow; if the liquid level is too low, it may affect the charge and discharge performance of the battery. After adjusting the liquid level, seal the battery to prevent external air from entering and the electrolyte from leaking, ensuring the tightness and integrity of the battery.

[0042] Based on the lead-acid battery vacuum formation process described above, the present invention also provides a device for the lead-acid battery vacuum formation process, including a vacuum formation device, as Figure 2As shown, the vacuum forming device includes a tooling table for placing the battery, a vacuum forming cover that can be covered above the battery, and a control system. A sealing ring is provided around the vacuum forming cover. After the vacuum forming cover and the tooling table are combined, a vacuum cavity is formed to place the battery in a vacuum environment. A vacuum pump system is connected to the vacuum forming cover. A vacuum degree detection device is provided on the vacuum pump system. The control system is electrically connected to the vacuum degree detection device and the vacuum pump system respectively. Through the setting of the vacuum forming device, the battery can be formed in a vacuum environment, the content of gases such as oxygen can be reduced, and the possible side reactions between lead and oxygen inside the battery can be reduced, which helps to improve the generation quality and utilization rate of the active substances on the battery plates, make the charge and discharge performance of the battery more stable, and extend the service life of the battery.

[0043] The vacuum pump system includes a vacuum pump, a vacuum buffer tank, a vacuum pipeline, and a vacuum control valve. The air extraction end of the vacuum pump is connected to the vacuum buffer tank. The air inlet of the vacuum buffer tank is connected to the vacuum forming cover through the vacuum pipeline. The vacuum control valve is installed on the vacuum pipeline. When the vacuum pump evacuates, the gas extracted from the vacuum forming cover first enters the vacuum buffer tank. The vacuum buffer tank plays a role in storing gas and buffering pressure fluctuations. During the air extraction process of the vacuum pump, since the gas flow rate and pressure may fluctuate, the vacuum buffer tank can store a part of the gas when the gas flow rate is large and release the gas when the gas flow rate is small, so that the gas flow rate and pressure entering the vacuum pump are relatively stable, reducing the load fluctuation of the vacuum pump, improving the working stability and efficiency of the vacuum pump. At the same time, the vacuum buffer tank can also prevent the gas from flowing back to the vacuum forming cover to a certain extent when the vacuum pump suddenly stops working. By adjusting the opening degree of the vacuum control valve, the gas flow rate entering the vacuum pump can be controlled, thereby adjusting the vacuum degree of the system. When the vacuum pump starts or stops, the vacuum control valve can control the on-off of the gas, preventing the gas from flowing back or pressure mutation from damaging the vacuum pump. In addition, the vacuum control valve can also be used to isolate different parts of the system, facilitating the maintenance and repair of the equipment.

[0044] The vacuum degree detection device is set as a vacuum gauge and a pressure transmitter. The control system includes a PLC controller. Both the vacuum gauge and the pressure transmitter are electrically connected to the PLC controller. After the vacuum degree signals detected by the vacuum gauge and the pressure transmitter are converted into electrical signals, they are transmitted to the PLC controller. These electrical signals can be voltage signals, current signals, etc. The PLC controller has an analog input module, which can receive and convert these analog signals into digital signals for processing and analysis. A required vacuum degree target value is preset inside the PLC controller. It compares the actually measured vacuum degree value received with the target value. If the actual value is higher than the target value, it means that the vacuum degree does not meet the requirements and further pumping is needed. If the actual value is lower than the target value, it may be necessary to stop pumping or appropriately supplement air to maintain a stable vacuum degree. According to the comparison result, the PLC controller issues a control signal through its output module. If it is necessary to increase the vacuum degree, the PLC will send an instruction to the vacuum control valve in the vacuum pump system to increase the valve opening, so that the vacuum pump increases the pumping force. If the vacuum degree is too high, the PLC controls the vacuum control valve to reduce the opening, or controls the air supplement valve to open for appropriate air supplement, and may also control the vacuum pump to reduce the rotation speed or stop working to adjust the vacuum degree. Through such a closed-loop control, the system vacuum degree is stabilized within the set range.

[0045] The vacuum forming device further includes a temperature control system. The temperature control system includes a temperature sensor and a heating device located in the vacuum chamber. One end of the temperature sensor is electrically connected to a temperature controller. Both the temperature controller and the heating device are connected to the PLC controller. The temperature in the vacuum chamber is sensed in real time by the temperature sensor. After the temperature controller receives the electrical signal transmitted by the temperature sensor, it converts it into a digital signal and compares it with the preset temperature target value. There are precise algorithms and circuits inside the temperature controller, which can accurately judge the deviation between the current temperature and the target temperature. The temperature controller sends the comparison result to the PLC controller in the form of a control signal. The PLC controller controls the heating device to increase the temperature, maintain a constant temperature or decrease the temperature according to the received signal.

[0046] The vacuum forming device further includes an electrolyte circulation system, which includes a circulation pump, a heat exchanger, a filter, and a liquid level controller. The inlet end of the circulation pump is connected to the outlet end of the filter, the outlet end of the circulation pump is connected to the inlet end of the heat exchanger, the outlet end of the heat exchanger is connected to the electrolyte inlet of the battery, the electrolyte outlet of the battery is connected to the inlet end of the filter, and the liquid level controller is installed at the upper end of the battery plate (such as at a distance of 10 ± 1 mm from the upper end of the battery plate). When processing the electrolyte circulation, the circulation pump starts to pump out the electrolyte from the external storage container of the battery and transports it to the filter through a pipeline. Under the action of pressure, the electrolyte enters the filter, and the filter intercepts the impurities and solid particles in it, allowing the filtered clean electrolyte to flow out from the filter outlet and flow towards the circulation pump; the circulation pump pressurizes the filtered electrolyte to make it enter the heat exchanger. In the heat exchanger, the electrolyte exchanges heat with the heat exchange medium (such as cold water or hot water), and according to the set temperature requirements, the temperature of the electrolyte is adjusted to an appropriate range; the electrolyte after temperature adjustment flows out from the heat exchanger and is transported to the electrolyte inlet of the battery through a pipeline, enters the battery interior, makes full contact with components such as the battery plates, and participates in the electrochemical reaction; the electrolyte after completing a certain reaction inside the battery flows out from the electrolyte outlet of the battery and returns to the inlet of the filter through a pipeline to enter the next round of filtration and circulation process. During the entire circulation process, the liquid level controller monitors the electrolyte liquid level in real time to ensure that the liquid level is always within the normal range and guarantee the stable operation of the electrolyte circulation system.

[0047] The vacuum forming device further includes a forming power supply system, which includes a programmable DC power supply, a current detection device, and a data acquisition system. The data acquisition system is electrically connected to the programmable DC power supply and the current detection device respectively.

[0048] Among them, the programmable DC power supply usually consists of a rectifier circuit, a filter circuit, a voltage stabilizing circuit, and a control circuit, etc. It converts the input alternating current into direct current through rectification and filtering, and then through the voltage stabilizing circuit and the control circuit, according to the preset program and parameters, precisely adjusts the output DC voltage and current to provide stable electrical energy for the formation of lead-acid batteries. Different output voltage and current values can be set through programming according to different battery types, capacities, and formation process requirements to achieve various charging modes such as constant current charging, constant voltage charging, and segmented charging.

[0049] Current detection devices generally work based on the Hall effect or resistance sampling principle. Current detection devices based on the Hall effect use Hall elements to sense the magnetic field generated by the current to measure the magnetic field, and then calculate the current magnitude. Current detection devices based on resistance sampling measure the voltage drop across a high-precision resistor connected in series in the circuit and calculate the current value according to Ohm's law. The detected current signal is converted into an electrical signal or a digital signal and fed back to the data acquisition system and the control circuit of the programmable DC power supply in real time to monitor and adjust the charging current.

[0050] The data acquisition system mainly consists of sensors, signal conditioning circuits, analog-to-digital conversion circuits, and microprocessors, etc. The sensors are responsible for collecting various physical quantities in the battery and the circuit, such as voltage, current, temperature, etc., and converting these physical quantities into electrical signals. The signal conditioning circuit amplifies and filters the weak electrical signals output by the sensors to meet the input requirements of the analog-to-digital conversion circuit. The analog-to-digital conversion circuit converts the analog signal into a digital signal, and the microprocessor processes, stores, and analyzes the digital signal, compares the collected data with the preset formation process parameters to determine whether the formation process is normal. At the same time, the data acquisition system can also upload the data to a computer or other monitoring devices through a communication interface so that the operator can understand the running status of the formation process in real time and remotely control and adjust the programmable DC power supply when necessary.

[0051] Example 2

[0052] Perform actual battery vacuum formation operations according to the method provided in Example 1. The operation steps and results are as follows Figure 3 shown:

[0053] Use the traditional formation process to perform formation on a 12V lead-acid battery for energy storage and a 12V lead-acid battery for power respectively. The formation method is the formation tank method. From the start to the end of the formation, the time required for the 12V lead-acid battery for energy storage to complete the formation is 96 hours, and the formation time for the 12V lead-acid battery for power is 97 hours.

[0054] From Figure 3 the test results in the table, it can be obtained that compared with the traditional formation process, the formation time is shortened by more than 20%, the utilization rate of the active material on the electrode plate is increased by more than 10%, and the first-pass rate of the product is increased by more than 10% when using the vacuum formation process provided in Example 1.

[0055] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A lead-acid battery vacuum formation process, characterized in that: The steps include: S1. placing the assembled battery in a vacuum formation device for pretreatment; S2. Injecting an electrolyte with a preset temperature into the battery under vacuum conditions; S3, under the premise of maintaining the vacuum state, the battery is charged with constant current in sections; S4, confirm whether the battery is formed. If not, return to S3. If it is formed, enter S5. S5. Degassing the battery using a vacuum system of a vacuum formation device; S6. After degassing, check and adjust the liquid level of the electrolyte in the battery. After the liquid level adjustment is completed, seal the battery.

2. A lead-acid battery vacuum formation process according to claim 1, characterized in that: In step S1, the vacuum formation device performs pretreatment on the battery, including vacuuming the battery and preheating the battery. The vacuum degree during vacuuming is -0.06MPa to -0.08MPa, and the pretreatment time is 15-20 minutes.

3. A lead-acid battery vacuum formation process according to claim 1, characterized in that: In step S3, the segmented constant current charging includes an activation stage, a conversion stage and a completion stage, wherein the current density in the activation stage is 0.8-1.2 mA / cm², and the time is 2-3 hours; the current density in the conversion stage is 1.5-2.0 mA / cm², and the time is 3-4 hours; the current density in the completion stage is 2.0-2.5 mA / cm², and the time continues until the formation is completed.

4. A lead-acid battery vacuum formation process according to claim 1, characterized in that: In step S6, the adjusted electrolyte level is 10±1 mm from the upper end of the electrode plate, and the adjusted electrolyte density is 1.280±0.005 g / cm³.

5. A device for vacuum forming process of lead-acid battery, based on the vacuum forming process of lead-acid battery according to any one of claims 1 to 4, characterized in that: The invention comprises a vacuum forming device, which comprises a workbench for placing batteries, a vacuum forming cover which can be covered on the batteries, and a control system. A sealing ring is arranged around the vacuum forming cover. The vacuum forming cover and the workbench are combined to form a vacuum cavity which puts the batteries in a vacuum environment. The vacuum forming cover is connected to a vacuum pump system, a vacuum degree detection device is arranged on the vacuum pump system, and the control system is electrically connected to the vacuum degree detection device and the vacuum pump system respectively.

6. The device for vacuum forming process of lead-acid battery according to claim 5, characterized in that: The vacuum pump system includes a vacuum pump, a vacuum buffer tank, a vacuum pipeline and a vacuum control valve. The vacuum pump's exhaust end is connected to the vacuum buffer tank, the vacuum buffer tank's air inlet is connected to the vacuum forming cover through the vacuum pipeline, and the vacuum control valve is installed on the vacuum pipeline.

7. The device for vacuum forming process of lead-acid battery according to claim 6, characterized in that: The vacuum degree detection device is configured as a vacuum gauge and a pressure transmitter, the control system comprises a PLC controller, and the vacuum gauge and the pressure transmitter are both electrically connected to the PLC controller.

8. The device for vacuum forming process of lead-acid battery according to claim 7, characterized in that: The vacuum forming device also includes a temperature control system, which includes a temperature sensor and a heating device located in the vacuum chamber. One end of the temperature sensor is electrically connected to a temperature controller, and the temperature controller and the heating device are both connected to a PLC controller.

9. The device for vacuum forming process of lead-acid battery according to claim 8, characterized in that: The vacuum formation device also includes an electrolyte circulation system, which includes a circulation pump, a heat exchanger, a filter and a liquid level controller. The inlet end of the circulation pump is connected to the outlet end of the filter, the outlet end of the circulation pump is connected to the inlet end of the heat exchanger, the outlet end of the heat exchanger is connected to the electrolyte inlet of the battery, the electrolyte outlet of the battery is connected to the inlet end of the filter, and the liquid level controller is installed on the upper end of the battery plate.

10. The device for vacuum forming process of lead-acid battery according to claim 9, characterized in that: The vacuum formation device also includes a formation power supply system, which includes a programmable DC power supply, a current detection device and a data acquisition system. The data acquisition system is electrically connected to the programmable DC power supply and the current detection device respectively.

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