KR20230159932A - Electrode plate manufacturing method of lead-acid battery for improving electrolyte stratification - Google Patents

Abstract

The present invention relates to a method of manufacturing electrode plates of a lead acid battery to improve electrolyte stratification. More specifically, the stratification phenomenon can be improved by increasing the electrical conductivity at the bottom of the electrode plate, and the CNT coated paper on the top and bottom of the substrate when applying the active material. This relates to a method of manufacturing electrode plates of a lead-acid battery to improve electrolyte stratification, which can improve the electrical conductivity of the electrode plates while maintaining the existing high working speed and mechanical strength by bonding them.
Through the present invention, it is possible to provide an initial basic performance improvement effect while increasing chemical conversion efficiency.

Description

{Electrode plate manufacturing method of lead-acid battery for improving electrolyte stratification}

The present invention relates to a method of manufacturing electrode plates of a lead acid battery to improve electrolyte stratification. More specifically, the stratification phenomenon can be improved by increasing the electrical conductivity at the bottom of the electrode plate, and the CNT coated paper on the top and bottom of the substrate when applying the active material. This relates to a method of manufacturing electrode plates of a lead-acid battery to improve electrolyte stratification, which can improve the electrical conductivity of the electrode plates while maintaining the existing high working speed and mechanical strength by bonding them.

A lead acid battery is a device that generates electromotive force through a chemical reaction. It is a secondary battery in which charging and discharging are repeated using lead peroxide (PbO2) as the anode, sponge-like lead (Pb) as the cathode, and dilute sulfuric acid (H2SO4) as the electrolyte. am.

This generates electrical force by forming a current flow by the potential difference between the anode and the cathode, and the electrolyte is filled higher than the height of the electrode plate group inserted into the precursor of the lead acid battery.

Since the temperature in high-temperature areas exceeds 40 degrees, it has a significant impact on the temperature of the lead-acid battery, especially the electrolyte temperature. When the lead-acid battery is installed in a vehicle, as the temperature increases, the number of times the air conditioner is used increases, causing repeated charging and discharging. This causes a decrease in electrolyte due to gas generation and evaporation of electrolyte due to ambient temperature.

If this phenomenon continues to occur, the specific gravity of the electrolyte becomes high, which means that the voltage recognized by the electrolyte at the battery terminal is measured to be higher than the actual value, a state of insufficient charge due to overvoltage occurs, and sulfation of the electrode plates is accelerated. This can shorten the life of the battery.

In order to improve the lifespan of lead acid batteries, Patent No. 10-0627037 is an electrolyte of lead acid batteries composed of distilled water and sulfuric acid, and sodium perborate is added thereto, and the mixing ratio of the components is 60 to 65% by weight of distilled water. , sulfuric acid (H2SO4) is 34 to 40% by weight, sodium perborate (NaBO3) is 0.1 to 5% by weight, or distilled water is 62.6% by weight, sulfuric acid (H2SO4) is 36.9% by weight, and sodium perborate (NaBO3) is An electrolyte composition for a lead acid battery, characterized in that it contains 0.5% by weight, has been disclosed.

However, this configuration is a factor that limits the composition of the lead acid battery electrolyte, and there is a problem that may limit the performance improvement of the electrolyte in the future.

Meanwhile, sulfuric acid is used as the electrolyte in lead acid batteries.

As time passes, stratification occurs naturally due to the difference in specific gravity between water and sulfuric acid in the electrolyte.

As stratification occurred, the upper layer, where the specific gravity was lowered, ended its life due to short-circuiting due to dendrite formation, or the lower layer suffered performance deterioration and lifespan was terminated due to excessive sulfation of active materials.

In addition, lead acid batteries are mainly used in a fixed form without movement from the time they are installed in vehicles or equipment.

Since the electrolyte is composed of an aqueous solution of sulfuric acid, a phenomenon in which the layers of sulfuric acid and water are divided due to the difference in specific gravity over time occurs.

Once stratification occurs, the designed performance of the lead-acid battery cannot be fully achieved. Separating the lead-acid battery and shaking it can help to achieve the initially intended performance.

However, there were practical difficulties in performing the process of separating and shaking the installed lead acid battery.

Therefore, starting from the motivation of "How can the stratification phenomenon be prevented?", a manufacturing method capable of preventing the stratification phenomenon was proposed through the present invention.

Republic of Korea Patent Publication No. 10-0627037

Therefore, the present invention was devised to solve the above conventional problems,

The purpose of the present invention is to improve the stratification phenomenon by increasing electrical conductivity by adhering CNT-coated paper to the bottom of the electrode plate.

Another object of the present invention is to maintain the existing high working speed and mechanical strength while simultaneously improving the electrical conductivity of the electrode plate by adhering CNT-coated paper to the top and bottom of the substrate when applying the active material.

In order to achieve the problem to be solved by the present invention, the method of manufacturing electrode plates of a lead acid battery for improving electrolyte stratification is,

CNT solution supply step (S100) of supplying the CNT solution to the spray device;

CNT coating layer forming step (S200) for uniformly spraying and coating paper using the spray device;

An active material preparation step (S300) of preparing active materials including smoke, sulfuric acid, water, and additives using a mixing device;

A material supply step (S400) for supplying the paper on which the CNT coating layer is formed to the lower supply roller 100 and the upper supply roller 200, and supplying the prepared active material to the hopper 300;

The electrode plate is supplied to the upper side of the lower supply roller 100, the lower supply roller 100 is rotated to adhere to the lower surface of the electrode plate, and the active material stored in the hopper 300 is supplied to the upper surface of the electrode plate, and the upper supply roller CNT coated paper adhesion step (S500) on the top and bottom of the electrode plate to attach it to the upper surface of the electrode plate by rotating (200);

The problem of the present invention is solved by including an electrode plate completion step (S600) in which the electrode plate with the paper on which the CNT coating layer is formed is adhered top and bottom is placed in the drying device, and then cured to finally manufacture the lead acid battery electrode plate.

The method for manufacturing electrode plates of a lead acid battery for improving electrolyte stratification according to the present invention is,

By adhering CNT-coated paper to the bottom of the electrode plate, electrical conductivity is increased, providing the effect of improving the stratification phenomenon.

In addition, adhering CNT-coated paper to the top and bottom of the substrate when applying the active material provides the effect of improving the electrical conductivity of the electrode plate while maintaining the existing high working speed and mechanical strength.

In addition, as the conversion efficiency increases, the initial basic performance improvement effect is excellent.

Figure 1 is a process diagram of a method for manufacturing electrode plates of a lead acid battery for improving electrolyte stratification according to an embodiment of the present invention.
Figure 2 is an illustration of CNT paper and active material applied to an electrode plate in a method of manufacturing an electrode plate of a lead acid battery to improve electrolyte stratification according to an embodiment of the present invention.
Figure 3 is an exemplary diagram showing coated paper whose lower portion is coated with conductive CNT in a method of manufacturing electrode plates of a lead acid battery for improving electrolyte stratification according to an embodiment of the present invention.

Hereinafter, since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail.

However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention.

These embodiments are provided to explain the present invention in more detail to those skilled in the art.

Accordingly, the shape of each element shown in the drawings may be exaggerated to emphasize a clearer description, and in explaining the present invention, if it is determined that a detailed description of the related known technology may obscure the gist of the present invention, the detailed description is provided. omit.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms.

Terms are used only to distinguish one component from another.

The terms used in the present invention are only used to describe specific embodiments and are not intended to limit the present invention.

Singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present invention, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

A method of manufacturing electrode plates of a lead acid battery for improving electrolyte stratification according to an embodiment of the present invention,

CNT solution supply step (S100) of supplying the CNT solution to the spray device;

CNT coating layer forming step (S200) for uniformly spraying and coating paper using the spray device;

An active material preparation step (S300) of preparing active materials including smoke, sulfuric acid, water, and additives using a mixing device;

A material supply step (S400) for supplying the paper on which the CNT coating layer is formed to the lower supply roller 100 and the upper supply roller 200, and supplying the prepared active material to the hopper 300;

The electrode plate is supplied to the upper side of the lower supply roller 100, the lower supply roller 100 is rotated to adhere to the lower surface of the electrode plate, and the active material stored in the hopper 300 is supplied to the upper surface of the electrode plate, and the upper supply roller CNT coated paper adhesion step (S500) on the top and bottom of the electrode plate to attach it to the upper surface of the electrode plate by rotating (200);

An electrode plate completion step (S600) in which the electrode plate on which the paper with the CNT coating layer is formed is adhered top and bottom is placed in the drying device, and then cured to finally manufacture the lead acid battery electrode plate.

At this time, the active material preparation step (S300) is,

The mixture is prepared by mixing 82 parts by weight of lead powder, 5 parts by weight of sulfuric acid with a specific gravity of 1.40, 11 parts by weight of water, and 1 part by weight of a negative electrode additive.

At this time, the electrode plate completion step (S600) is,

The temperature of the drying device is set to 300 ~ 400℃, and curing is performed for 1 hour to 7 hours.

Meanwhile, the manufacturing method of the present invention provides a lead acid battery containing electrode plates of a lead acid battery to improve electrolyte stratification, thereby improving the stratification phenomenon by increasing electrical conductivity by adhering CNT-coated paper to the bottom of the electrode plate. provides.

Hereinafter, the method for manufacturing electrode plates of a lead acid battery for improving electrolyte stratification according to the present invention will be described in detail through examples.

Figure 1 is a process diagram of a method for manufacturing electrode plates of a lead acid battery for improving electrolyte stratification according to an embodiment of the present invention.

As shown in Figure 1, the method of manufacturing electrode plates of a lead acid battery to improve electrolyte stratification is,

CNT solution supply step (S100) of supplying the CNT solution to the spray device;

CNT coating layer forming step (S200) for uniformly spraying and coating paper using the spray device;

An active material preparation step (S300) of preparing active materials including smoke, sulfuric acid, water, and additives using a mixing device;

A material supply step (S400) for supplying the paper on which the CNT coating layer is formed to the lower supply roller 100 and the upper supply roller 200, and supplying the prepared active material to the hopper 300;

The electrode plate is supplied to the upper side of the lower supply roller 100, the lower supply roller 100 is rotated to adhere to the lower surface of the electrode plate, and the active material stored in the hopper 300 is supplied to the upper surface of the electrode plate, and the upper supply roller CNT coated paper adhesion step (S500) on the top and bottom of the electrode plate to attach it to the upper surface of the electrode plate by rotating (200);

It includes an electrode plate completion step (S600) in which the electrode plate with the paper on which the CNT coating layer is formed is adhered top and bottom is placed in the drying device, and then cured to finally manufacture the lead acid battery electrode plate.

To be specific, the CNT solution supply step (S100) is a process of supplying the CNT solution to a spray device, and the CNT coating layer forming step (S200) is a process of uniformly spraying and coating paper using the spray device.

In other words, the CNT solution is supplied to the spray device, preferably in an amount of 50 to 70 parts by weight based on the fuel content.

50 to 70 parts by weight of the CNT solution is added based on the weight of the fuel. If the weight of the CNT solution is less than 50 parts by weight, the electrical conductivity of the electrode plate is similar to the conventional one, so it is a small amount that is difficult to expect to improve performance, and 70 parts by weight is added. If it exceeds 70 parts by weight, it is difficult to expect a cycle of more than 70 parts by weight of the life cycle, as proven in the accelerated life test, and only provides a cause for price increase.

Therefore, it would be desirable to add the CNT solution within the above range.

Then, the paper is uniformly sprayed and coated using the spray device, for example, using any one coating method selected from the group consisting of doctor blade method, spray coating method, and spin coating method. Application, that is, coating.

At this time, preferably, the coating range is characterized by spraying the CNT solution to the lower part based on the center of the paper.

Specifically, the purpose is to improve the stratification phenomenon by increasing the electrical conductivity at the bottom of the electrode plate. To this end, when the electrode plate manufacturing process is performed, paper coated with conductive CNTs is adhered to the bottom of the electrode plate.

Therefore, the electrochemical reaction rate at the bottom of the electrode plate, where the physical conductivity is low, can be increased, and the amount of gas generated at the bottom also increases during charging, so that the lower electrolyte rises with the gas, thereby improving the stratification phenomenon.

Thereafter, the active material preparation step (S300) is a process of preparing active materials including smoke, sulfuric acid, water, and additives using a mixing device.

Specifically, a mixture is prepared by mixing 80 parts by weight of lead powder, 5 parts by weight of sulfuric acid with a specific gravity of 1.40, 11 parts by weight of water, and 1 part by weight of a cathode additive or anode additive.

Then, by stirring at a temperature of 50 to 75 degrees, a mixture with a density of 60 to 80 g/In3 is obtained.

Thereafter, in the material supply step (S400), the paper on which the CNT coating layer is formed is supplied to the lower supply roller 100 and the upper supply roller 200, and the prepared active material is supplied to the hopper 300.

That is, as shown in FIG. 2, paper with a CNT coating layer is supplied to the lower supply roller 100 and the upper supply roller 200, and the prepared active material is supplied to the hopper 300, thereby preparing for material supply. will be completed.

Afterwards, in the electrode plate upper and lower CNT coating paper adhesion step (S500), the electrode plate is supplied to the upper side of the lower supply roller 100, the lower supply roller 100 is rotated to adhere to the lower surface of the electrode plate, and the electrode plate is placed in the hopper 300. The stored active material is supplied to the upper surface of the electrode plate, and the upper supply roller 200 is rotated to adhere it to the upper surface of the electrode plate.

What is characteristic is that the lower supply roller 100 and the upper supply roller 200 must be formed at positions spaced apart from each other at a certain distance, and a hopper must be formed between them.

This is because only with this configuration can the active material be applied to the upper and lower surfaces of the electrode plate with a uniform thickness.

In addition, the operation of the roller and hopper is possible under the control of the controller, and since the configuration of the controller is a general configuration, detailed description will be omitted.

Thereafter, the electrode plate completion step (S600) is a process of putting the electrode plate on which the paper with the CNT coating layer is adhered top and bottom into a drying device and then curing it to finally manufacture the lead acid battery electrode plate.

Specifically, the temperature of the drying device is set to 300 to 400°C and curing is performed for 1 to 7 hours.

If the temperature is below the above range, the CNT coating layer may not be properly cured, which may cause problems with conductivity. If the temperature exceeds the above temperature range, cracks may occur in the paper composed of the CNT coating layer. Therefore, it is preferable to cure within the above range. do.

In general, during the manufacturing process of lead acid battery electrode plates, paper tissue or PET nonwoven fabric is widely used on the top and bottom of the electrode plates to uniformly apply active materials to the substrate.

At this time, in the present invention, if the CNT coating layer is applied only to the lower part of the paper and dried, the coated paper can be adhered to the upper and lower parts of the electrode plate when applying the active material, thereby improving the electrical conductivity of the electrode plate while maintaining the existing high working speed and mechanical strength. This increases chemical efficiency and improves initial performance.

In addition, because CNT-coated paper is adhered to the bottom of the electrode plate, electrical conductivity is increased, providing the effect of improving the stratification phenomenon.

As described in detail above, in order to determine the effect of the present invention, basic performance and life tests were conducted on the electrode plate manufactured based on the above-described manufacturing process.

Conventional products described later refer to products manufactured using electrode plates coated with active materials used in lead acid batteries (BX80) manufactured by the applicant, and improved products include electrode plates including a CNT coating layer through the manufacturing method of the present invention. It refers to the product being made.

In addition, through subsequent processes such as assembly and chemical conversion to impart electrical conductivity to the substrate, a conventional product and an improved product with a final capacity of 70 Ah (20 hour rate capacity) were manufactured, and the effect of applying an electrode plate including a CNT coating layer was demonstrated. To prove this, charge acceptability and 50% DoD durability tests were conducted.

1) Charge Acceptance test (CA: Charge Acceptance test)

A fully charged sample is discharged for 2.5 hours at room temperature (25±2℃) at a 5-hour rate current (17.5A based on 70Ah), and then left at 0±2℃ for more than 12 hours.

Afterwards, charge it at a constant voltage of 14.4V±0.1V and measure the current at 10 minutes of charging.

As a result of the test, it was found that the improved battery's conductivity and charging efficiency were high, and the current increased by 15% in about 10 minutes compared to the conventional product.

division hour Conventional products improvement




Charge income 1 min 27.25 28.14 2 minutes 24.21 26.93 3 minutes 22.14 25.71 4 minutes 21.25 24.52 5 minutes 20.11 23.73 6 minutes 19.35 22.41 7 minutes 18.74 20.46 8 minutes 17.68 19.79 9 minutes 17.04 18.47 10 minutes 16.43 18.22

In the case of conventional products, tissue paper made of non-woven fabric or paper is pressed to the surface of the active material to create an active material support. This active material support is only used to support the active material applied to the grid so that it does not fall off the grid. This active material support (non-woven or Tissue Paper is characterized by acid resistance, heat resistance, and oxidation resistance.

However, since this active material support supports the active material only by compression when applying the active material to the grid, it is easy for the active material to fall off from the grid depending on the user's usage conditions, operating conditions, and usage environment when mounted on a vehicle and used. The detachment is accelerated, resulting in reduced starting power or early end of life.

However, the prior art has problems in providing performance in the current social environment that requires increasingly higher basic performance.

For example, as various electronic devices and communications are increasingly used in vehicles, the use of electricity increases accordingly, and as they are frequently used at high temperatures due to the effects of global warming, the robustness of battery performance must be guaranteed.

Therefore, in order to improve this problem, in the present invention, a CNT solution with excellent electrical conductivity and excellent adhesion was used.

Therefore, it is possible to achieve higher output and improved life expectancy, ultimately improving the basic performance and lifespan of the battery.

Experimental data for this will be described later.

2) Accelerated life test (SAE J2801)

The lead acid battery is subjected to 34 charge/discharge cycles in a water bath at 75°C for approximately one week, similar to typical vehicle conditions.

After performing 34 cycles, the life test is conducted by discharging at 200A for 10 seconds, and if the voltage is maintained above 7.2V, the cycle is repeated 34 times.

Additionally, the test is stopped if the charging current rises above 15A or the discharge voltage falls below 12.0V during the cycle.

Table 2 below shows the results of the SAE J2801 test, showing the voltage when discharged at 200A for 10 seconds for every 34 charge/discharge cycles.

cycle CNT 0 parts by weight CNT 30 parts by weight CNT 50 parts by weight CNT 70 parts by weight CNT 90 parts by weight 34 11.82 11.83 11.85 11.88 11.89 68 11.76 11.77 11.81 11.85 11.87 102 11.72 11.73 11.79 11.83 11.84 136 11.69 11.71 11.78 11.77 11.82 170 11.65 11.68 11.73 11.75 11.80 204 11.55 11.61 11.68 11.73 11.76 238 11.43 11.45 11.63 11.69 11.70 272 7.2 and below 7.2 and below 11.59 11.67 11.63 306 7.2 and below 11.63 11.55 340 7.2 and below 7.2 and below

As shown in Table 2 above, the test results show that when not coated with a CNT solution or when 30 parts by weight is provided to a spray device and coated with a thickness of about 1 to 3 mm on the area of a general grid, the lifespan is 238 cycles, but when 50 parts by weight is sprayed When coated by providing it to a device, the lifespan is 272 cycles, and when 70 parts by weight is provided to a spray device and coated, the lifespan is 306 cycles, providing a 28.5% improvement in lifespan.

However, it can be seen that even if the CNT solution exceeding 70 parts by weight is provided to the spray device and coated to a thickness of 1 to 3 mm, the lifespan does not increase further at 306 cycles. Accordingly, the effective range is 0 parts by weight to 90 parts by weight. It is 50 to 70 parts by weight, and the most optimal value is 70 parts by weight, so it is preferable to add it within the above range.

This appears to be the result of improved electrical conductivity between active materials, lowering electrical resistance, and increased charging efficiency due to increased reaction surface area, resulting in a decrease in the sulphation content accumulated in the active material.

In other words, it showed a 28% improvement in lifespan compared to conventional products, showing that spraying the CNT solution on paper to form a coating layer had a positive effect on increasing the lifespan.

Specifically, by supplying an electrode plate containing a CNT coating layer, the electrochemical reaction rate at the bottom of the electrode plate, whose physical conductivity decreases over time, can be increased, and the amount of gas generated at the bottom also increases during charging, so that the lower electrolyte is mixed with gas and This result shows that the stratification phenomenon was able to be improved with the rise.

division Conventional products improvement R.C. 118 min 132min

Meanwhile, Table 3 is a comparison table regarding the RC capacity during performance evaluation. In the case of a conventional lead acid battery, the RC capacity was found to be 118 min, and in the case of an improved product using the electrode plate containing the CNT-coated paper of the present invention, the RC capacity was 118 min. The RC capacity was found to be 132 min.

This is a result showing that as time passes, the amount of gas generated in the lower part increases during charging, and the lower electrolyte rises with the gas, thereby improving the stratification phenomenon. The stratification phenomenon is greatly alleviated, resulting in a 10% increase in RC capacity. Could know.

The present invention provides the effect of improving the stratification phenomenon by increasing electrical conductivity by adhering CNT-coated paper to the bottom of the electrode plate.

In addition, adhering CNT-coated paper to the top and bottom of the substrate when applying the active material provides the effect of improving the electrical conductivity of the electrode plate while maintaining the existing high working speed and mechanical strength.

Those skilled in the art to which the present invention pertains as described above will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. Therefore, the embodiments described above should be understood in all respects as illustrative and not limiting.

S100: CNT solution supply step
S200: CNT coating layer formation step
S300: Active material preparation step
S400: Material supply stage
S500: CNT coating paper adhesion step on top and bottom of electrode plate
S600: Plate completion stage

Claims (4)

In the method of manufacturing electrode plates of a lead acid battery to improve electrolyte stratification,
CNT solution supply step (S100) of supplying the CNT solution to the spray device;
CNT coating layer forming step (S200) for uniformly spraying and coating paper using the spray device;
An active material preparation step (S300) of preparing active materials including smoke, sulfuric acid, water, and additives using a mixing device;
A material supply step (S400) for supplying the paper on which the CNT coating layer is formed to the lower supply roller 100 and the upper supply roller 200, and supplying the prepared active material to the hopper 300;
The electrode plate is supplied to the upper side of the lower supply roller 100, the lower supply roller 100 is rotated to adhere to the lower surface of the electrode plate, and the active material stored in the hopper 300 is supplied to the upper surface of the electrode plate, and the upper supply roller CNT coated paper adhesion step (S500) on the top and bottom of the electrode plate to attach it to the upper surface of the electrode plate by rotating (200);
A lead-acid battery for improving electrolyte stratification, comprising an electrode plate completion step (S600) in which the electrode plate with the paper on which the CNT coating layer is formed is adhered top and bottom is placed in a drying device, and then cured to finally manufacture the lead-acid battery electrode plate. Method of manufacturing electrode plates.
According to clause 1,
The active material preparation step (S300) is,
A method of manufacturing electrode plates of a lead acid battery for improving electrolyte stratification, characterized in that a mixture is prepared by mixing 82 parts by weight of lead powder, 5 parts by weight of sulfuric acid with a specific gravity of 1.40, 11 parts by weight of water, and 1 part by weight of a negative electrode additive.
According to clause 1,
In the plate completion step (S600),
A method of manufacturing electrode plates of a lead acid battery to improve electrolyte stratification, characterized in that the temperature of the drying device is set to 300 ~ 400 ℃ and cured for 1 hour to 7 hours.
By the manufacturing method of claim 1,
A lead-acid battery containing the electrode plates of a lead-acid battery to improve electrolyte stratification.