KR102225207B1 - Manufacturing method of PE Separator for lead acid battery using PVA coating - Google Patents

Abstract

The present invention relates to a high-performance PE separator manufacturing method through hydrophilic polymer coating and, more specifically, to a high-performance PE separator manufacturing method through hydrophilic polymer coating, that changes the surface of a PE separator to be hydrophilic, improves the permeability of an electrolyte, and allows the electrolyte inside and outside the separator to circulate in charged and discharged states to improve the durability and performance of a lead-acid battery by coating the PE separator with a hydrophilic polymer material to uniformly form a hydrophilic polymer coating layer. Through the present invention, by coating the PE separator with the hydrophilic polymer material to uniformly form the hydrophilic polymer coating layer, the surface of the PE separator is changed to be hydrophilic, and the permeability of the electrolyte is improved, so that the electrolyte inside and outside the separator is allowed to circulate in the charged and discharged states. Therefore, the effect of improving the durability and performance of a lead-acid battery is provided.

Description

Manufacturing method of PE Separator for lead acid battery using PVA coating}

The present invention relates to a method of manufacturing a high-performance PE separator through a hydrophilic polymer coating, and more particularly, by coating a hydrophilic polymer material on the PE separator in order to uniformly form a hydrophilic polymer coating layer, the surface of the PE separator is made hydrophilic. The present invention relates to a method for manufacturing a high-performance PE separator through a hydrophilic polymer coating capable of improving the durability and performance of a lead-acid battery by improving the permeability of the electrolyte and allowing the electrolyte inside and outside the separator to circulate in a charged and discharged state.

Basically, a battery separator is a nonconductor electronically and a conductor ionically.

That is, the separator prevents direct electronic contact between electrodes of opposite polarity, while enabling ionic current between the electrodes. In order to satisfy these two functions, the separator generally has as little pores as possible to prevent electronic short circuits by dendrites or plate particles, and the internal battery resistance. It is a porous non-conductor with as high porosity as possible to minimize

In lead acid batteries, the separator also determines the appropriate electrode spacing, thereby defining the amount of electrolyte that participates in the cell reaction.

The separator must be stable throughout the life of the battery (refer to Korean Patent Publication No. 2001-0042790).

As is well known, lead acid batteries used in automobiles are rechargeable and dischargeable secondary batteries, which use dilute sulfuric acid (H2SO4) as an electrolyte, and lead dioxide (PbO2) to the positive (+) electrode as an active material. When the negative (-) electrode is coated with lead (Pb) and connected to an external circuit, electricity flows and discharges (the process in which the composition of the active material of the initial positive electrode and negative electrode changes to lead sulfate (PbSO4)) and current from the outside. It uses the principle of charging (the process of changing lead sulfate into the initial positive active material and negative active material before discharge) by flowing it.

The structure of such a lead acid battery is briefly presented in FIG. 1.

The positive electrode plate 1 and the negative electrode plate 2 to which the active material is applied have various types depending on the manufacturing method, and as an example, FIG. 2 shows the structure of a paste-type electrode targeted by the present invention.

This consists of a grid-shaped substrate 5 and a paste-like active material applied thereon.

Usually, the substrate 5 is made of an alloy containing antimony (Sb) and calcium (Ca) as the main components in order to enhance mechanical strength and corrosion resistance, and the manufacturing method is poured into a mold and cast by gravity or cast by a continuous rolling method. (Refer to Korean Patent Publication No. 2000-0031876)

The active material is a part that plays an important role in the performance of the lead acid battery. A fine powdery lead oxide (Pb0) is applied in a dilute sulfuric acid aqueous solution and a paste on the substrate in an applicator continuously to aging, drying, and electrically oxidizing and reducing. It is manufactured through a chemical conversion process.

Lead dioxide (PbO2), which is a positive electrode active material, contains a myriad of oxidized lead microparticles and is rich in porosity, so that the electrolyte can freely diffuse and penetrate between the particles.

In addition, the active material of the negative electrode plate, sea surface lead, is also rich in porosity and reactivity, allowing the electrolyte to freely penetrate.

The positive electrode plate and the negative electrode plate manufactured as described above are separated by a separator 3, which is a porous non-conductor, to prevent direct contact between the two electrode plates, and are assembled by putting them in a product roll (a container constituting a product).

The lead-acid battery made in this way exhibits electrical performance by an internal electrolyte, and is charged and discharged in a vehicle.

Lead-acid batteries installed in automobiles affect the life of lead-acid batteries according to the driving conditions of the vehicle (average daily mileage, driver driving habits, road conditions) and electrical load conditions of the vehicle's electronic parts.

However, operating conditions and excessive electric load in severe conditions decrease the bonding strength of the positive electrode plate active material (PbO2) rich in porosity, and this drop-off of the active material lowers the reactivity of the positive electrode plate and the negative electrode plate, leading to a decrease in electrical performance, ultimately leading to lead. It becomes a factor that decreases the life of the storage battery.

As described above, in order to reduce the dropout of the active material of the electrode plate, an active material having an electrochemical activity is applied to the substrate on which the electrode is cast or expanded, and a nonwoven fabric made of a thermoplastic resin is pressed to the surface of the active material to a certain depth, thereby manufacturing an electrode plate. In a lead-acid battery consisting of a plurality of electrode plates with an active material layer attached to the surface, a thin fiber mesh is covered on the outer surface of the active material layer, and a known separator formed of a polyethylene-based polymer material and a protrusion formed on the inner surface of the lead acid battery is used. By installing on the outer surface, it is possible to reduce the dropout of the active material, suppress the growth of dendrites, and reduce the thickness of the separator, thereby reducing the size of the lead acid battery.

The use of the non-woven fabric and the fibrous mesh is widely used in accordance with each characteristic in the battery, and in the balance of the battery life and discharge performance of the separator (isolator plate) made of a microporous film and a non-woven fabric in a nickel-zinc secondary battery. In order to regulate the optimum amount of electrolyte, it is possible to extend the life of the battery by increasing the utilization rate of the zinc anode. The Ni anode wrapped with polypropylene nonwoven fabric and the Zn anode wrapped with cotton nonwoven and polypropylene nonwoven are wrapped with polypropylene microporous film. In a battery for adjusting the ratio of the amount of the electrolyte impregnated in the separator and the total amount of the electrolyte in the battery, a polypropylene nonwoven fabric separating between the Ni positive electrode and the Zn negative electrode is formed in the alkaline zinc storage battery, and the Ni positive electrode, the Zn negative electrode and the polypropylene nonwoven In an alkaline zinc storage battery in which a multilayer separator having a plurality of layers of microporous membranes is disposed outside of the multilayer separator, a cotton nonwoven fabric is formed between the Zn negative electrode of the multilayer separator and the polypropylene nonwoven fabric. Polymers in batteries such as separators prepared from a blend of polyolefin copolymers and oligomers of polyolefin polymers, including microporous polyolefin membranes having a porosity in the range of 30-80% and an average pore size in the range of 002-20 microns in the manufacture of separators Polyolefin-based nonwoven fabrics and membranes composed of are widely used.

Currently, most of the separators used in lead acid batteries are rechargeable porous polyethylene separators. The main purpose is to prevent short circuits by preventing direct contact between the positive and negative plates, and the secondary purpose is to prevent ions due to small resistance between the positive and negative plates. It must enable current flow.

Therefore, in order to use electronic products in various vehicles at the same time, the permeability of the electrolyte is increased compared to the conventional PE separator so that the electrolyte inside and outside the separator can be smoothly circulated in the state of charging and discharging. There is a need to manufacture a separator in order to improve the problem of deteriorating the performance of the lead acid battery.

Korean Patent Application Publication No. 2001-0042790 Korean Patent Publication No. 2000-0031876

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

By coating a hydrophilic polymer material on the PE separator to uniformly form the hydrophilic polymer coating layer, the surface of the PE separator is changed to hydrophilic, improving the permeability of the electrolyte so that the electrolyte inside and outside the separator is circulated in the state of charge and discharge. Thus, it is intended to provide a method of manufacturing a high-performance PE separator through a hydrophilic polymer coating that can improve the durability and performance of lead-acid batteries.

In order to achieve the problem to be solved by the present invention, a method of manufacturing a high-performance PE separator through a hydrophilic polymer coating according to an embodiment of the present invention,

Hydrophilic polymer coating PE isolating plate manufacturing step (S100) for coating a hydrophilic polymer material on the PE isolating plate in order to uniformly form the hydrophilic polymer coating layer on the PE isolating plate; And

By including the hydrophilic polymer coating PE isolating plate completion step (S200) for manufacturing a high-performance PE isolating plate through a drying process of the prepared PE isolating plate containing the hydrophilic polymer coating layer, for improving the durability and performance of the lead storage battery. You will solve the task.

Through the method of manufacturing a high-performance PE separator through hydrophilic polymer coating, which is the present invention, by coating a hydrophilic polymer material on the PE separator in order to uniformly form the hydrophilic polymer coating layer, the surface of the PE separator is changed to hydrophilicity, and thus the permeability of the electrolyte solution. By improving the effect of improving the durability and performance of the lead acid battery by allowing the electrolyte inside and outside the separator to circulate in a charged and discharged state.

1 is a schematic cross-sectional view showing the internal structure of a typical lead acid battery.
2 is a cross-sectional view of a portion of an electrode constituting a general lead acid battery.
3 is a flowchart of a method of manufacturing a high-performance PE separator through a hydrophilic polymer coating according to an embodiment of the present invention.
4 is a graph comparing an improved product manufactured by a high-performance PE separator manufacturing method through a hydrophilic polymer coating according to an embodiment of the present invention and a conventional product manufactured through a general manufacturing method, according to the standards of the American Automobile Engineers Association. This is a graph showing the lifespan in a high-temperature environment.
FIG. 5 is a graph comparing an improved product manufactured by a method for manufacturing a high-performance PE separator through a hydrophilic polymer coating according to an embodiment of the present invention and a conventional product manufactured by a general manufacturing method, and is a graph showing a charge importability test.

A method of manufacturing a high-performance PE separator through a hydrophilic polymer coating according to an embodiment of the present invention,

Hydrophilic polymer coating PE isolating plate manufacturing step (S100) for coating a hydrophilic polymer material on the PE isolating plate in order to uniformly form the hydrophilic polymer coating layer on the PE isolating plate; And

It characterized in that it comprises a; hydrophilic polymer coating PE isolating plate completion step (S200) for manufacturing a high-performance PE isolating plate through a drying process the PE isolating plate containing the prepared hydrophilic polymer coating layer.

At this time, by coating the hydrophilic polymer material, the surface of the PE separator is changed to hydrophilicity to improve the permeability of the electrolyte so that the electrolyte inside and outside the separator is circulated in the state of charge and discharge, thereby improving the durability of the lead acid battery. do.

At this time, the hydrophilic polymer material,

It is characterized in that it is polyvinyl alcohol (PVA).

At this time, by the method of manufacturing a high-performance PE separator through the hydrophilic polymer coating,

When the manufactured lead acid battery has a capacity of 80Ah ~ 87Ah,

The lifetime is characterized by being able to provide a durability improvement in the range of 20% to 25% from 2,304 to 2,440 cycles at 1,920 cycles.

At this time, by providing a high-performance PE isolating plate including a hydrophilic polymer coating layer prepared by the above manufacturing method, the effect of improving the durability and performance of the lead acid battery is provided.

Hereinafter, it will be described in detail through examples of a method for manufacturing a high-performance PE separator through a hydrophilic polymer coating according to the present invention.

3 is a flowchart of a method of manufacturing a high-performance PE separator through a hydrophilic polymer coating according to an embodiment of the present invention.

As shown in Figure 3, the method of manufacturing a high-performance PE separator through a hydrophilic polymer coating according to the present invention,

Hydrophilic polymer coating PE isolating plate manufacturing step (S100) for coating a hydrophilic polymer material on the PE isolating plate in order to uniformly form the hydrophilic polymer coating layer on the PE isolating plate; And

And a hydrophilic polymer coating PE isolating plate completion step (S200) for manufacturing a high-performance PE isolating plate through a drying process of the PE isolating plate including the hydrophilic polymer coating layer prepared above.

In the present invention, by coating a hydrophilic polymer material on the PE separator to uniformly form the hydrophilic polymer coating layer, the surface of the PE separator is changed to hydrophilic, thereby improving the permeability of the electrolyte, so that the electrolyte inside and outside the separator is charged and discharged. By allowing it to be circulated in, it provides an effect that can improve the durability and performance of the lead acid battery.

Specifically, in order to use electronic products in various vehicles at the same time, the permeability of the electrolyte is increased compared to the conventional PE separator so that the electrolyte inside and outside the separator can be circulated smoothly in the state of charging and discharging. By improving the problem of deteriorating the performance of the lead acid battery by using, it was found that it was possible to improve the basic performance by more than 5% and the durability by 25% compared to the conventional lead acid battery, and to complete the present invention through a confirmation test. It came to.

Next, the manufacturing steps will be described in detail.

The hydrophilic polymer coating PE isolation plate manufacturing step (S100) is a process for coating a hydrophilic polymer material on the PE isolation plate in order to uniformly form a hydrophilic polymer coating layer on the PE isolation plate.

Specifically, the energy emitted in the product during battery formation and charging and discharging is reduced.

This is because the amount of energy lost during electron transfer decreases due to the decrease in internal resistance.

The PE separator is, for example, polyethylene (PE), polypropylene (PP), polyester (PET), and the like as fibers forming the nonwoven fabric.

Staple Fiber Nonwoven fabrics are sometimes made of synthetic resin of a single material, and synthetic resin staple fibers of two or more materials are mixed and used.

Filament nonwoven fabric is mainly made of polyethylene (PE), polypropylene (PP), and polyester (PET) fibers as a single material.

In forming the nonwoven fabric, the short fiber nonwoven fabric is chemical bonding using an adhesive, thermal bonding using heat or fiber properties, needle punching, and melt blown. , Stitch Bonding, etc. are being used. Filament nonwoven fabrics are made into a sheet by uniformly stacking the melt-spun yarn on a conveyor, and passing a heater embossing roller through it. The spunbond method for making nonwoven fabrics is mainly used.

The process of manufacturing the PE separator was specifically disclosed in Korean Patent No. 10-0645970, filed and registered by the present applicant, and briefly describes the registered patent, in which a nonwoven fabric is attached to the substrate to form a separator. In the case, as shown in Fig. 3 of the registered patent, the plate body 6 is wound on a separator roll 7 attached to an enveloping machine, and an additional nonwoven fabric roll 8 is installed. The non-woven fabric 9 is wound on the plate body 6 and the non-woven fabric 9 together, and the plate body 6 and the non-woven fabric 9 are bonded together to form a separator member.

In manufacturing the separator member by the bonding device as shown in FIG. 3, the plate body 6 in which a plurality of ribs 62 are formed, and the protrusions 62 as shown in FIG. 4 Apply a heat-resistant and chemical-resistant hot melt and then laminating a non-woven fabric thereon, or attach the plate body 6 and the non-woven fabric 9 as shown in Fig. 5 for unit isolation through an ultrasonic (Ultrasonic) fusion process. It can be attached by forming the junction 10 at both ends of the plate.

On the other hand, according to an additional aspect, prior to the hydrophilic polymer-coated PE separator manufacturing step (S100), a contaminant removing step for removing contaminants from the surface of the PE separator; And

For surface modification, a pretreatment step for performing pretreatment using oxygen plasma may include.

By treating the hydrophobic PE separator to be hydrophilic through the pretreatment step, it is possible to uniformly form a hydrophilic polymer coating layer on the PE separator.

Currently, polyethylene (PE) porous polymer membranes are widely used as separators for lead-acid batteries, but they are vulnerable to mechanical damage such as thermal shrinkage, impact, rupture due to external force, and penetration at high temperatures.

In the case of breakage of the separator, an internal short circuit may occur due to direct contact between the positive and negative electrodes, which is considered to be the main cause of the lead acid battery's lifespan and ignition.

Therefore, the separator of the lead acid battery should have little shrinkage at high temperature and should have mechanical strength to withstand external impact.

It is an important issue related to battery safety that the separator maintains its film shape at a temperature near its melting point to suppress internal short circuits.

In order to solve this problem, there is a method of coating an inorganic material or an organic material having high heat resistance.

Currently, the coating method of the separator is a coating method using RF Magnetron Sputter, a coating method using bar coating, and a pin coating method.

At this time, preferably, a spin coating method may be used, and the spin coating method is a versatile coating technology capable of forming a uniform thin film that can be reproduced with high efficiency at a very easy and inexpensive manner, and is widely used in the production of solution-processed organic/inorganic electronic devices. Is being used.

Specifically, the contaminant removing step is a process for removing contaminants on the surface of the PE separator.

That is, in order to coat the hydrophilic polymer coating layer on the PE separator, contaminants adhered to the surface of the separator are preferentially removed.

If contaminants are present on the surface of the separator, errors may occur in the final product due to inconsistent coating.

Thereafter, in the pretreatment step, for surface modification, pretreatment is performed using oxygen plasma.

That is, pretreatment for surface modification is required.

For this purpose, most problematic matters during coating adhesion are contamination by organic substances on the surface, so it must be removed.

In order to remove this, it is preferable to use the most efficient and widely used oxygen plasma.

On the other hand, according to an additional aspect, the pretreatment step,

Surface treatment by using an inert gas such as helium or argon instead of oxygen plasma to form a stable crosslinked layer by generating free radicals by being cut off by carbon-to-carbon bonds on the surface, ions in which carbon and hydrogen are bonded, or by vacuum ultraviolet rays. It is characterized in that to proceed.

By using inert gas such as helium or argon, carbon-carbon bonds or carbon-hydrogen bonds on the surface are cut off by ions or vacuum ultraviolet rays to generate free radicals to form a stable crosslinked layer to proceed with surface treatment. .

On the other hand, in the case of using the spin coating method to uniformly form the hydrophilic polymer coating layer on the PE isolating plate in the hydrophilic polymer coating PE isolating plate manufacturing step (S100), the spin coating is performed at a rotation speed of 1,000 to 5,000 rpm, After coating, it is dried at room temperature for 12 hours, and then pre-heat-treatment is performed at 600° C. for 2 hours in air.

If the rotational speed is less than the above, the process time may be lengthened, which may cause an increase in manufacturing cost. If the rotational speed is exceeded, uniform coating is not possible.

Therefore, it would be desirable to carry out the coating within the range of rotational speeds described above.

In addition, when the temperature is exceeded, the coating layer may be cracked, and when the temperature is less than the above-described temperature, the coating layer cannot be uniformly applied, so it is preferable to observe the above temperature.

At this time, the characteristic is that the coating, drying, and preheating processes are repeated 3 to 5 times in order to coat a certain thickness on the PE separator, and then finally heat treated at 600°C or less for 2 hours in air to prevent cracks and pores in the coating layer. None, and stable bonding of the PE separator and the hydrophilic polymer coating layer is possible.

As described above, the reason for repeating the coating several times is to improve the heat resistance of the separator.

If the number of repetitions is exceeded, the coating layer may become too thick to cause problems in use. If the number of repetitions is less than the number of repetitions, the desired thickness of the coating layer may not be expected.

In addition, the final process is performed so that there are no cracks and pores in the coating layer by heat treatment at 600° C. or less in air for 2 hours, and stable bonding of the PE separator and the hydrophilic polymer coating layer is possible.

At this time, in the general spin coating process, the treatment is performed at 1400°C. In this case, since damage to the PE separator occurs during the heat treatment process, it is preferable to perform heat treatment within the above-described temperature range.

Meanwhile, in order to provide the hydrophilic polymer coating layer in the present invention, polyvinyl alcohol (PVA), a binder, and a solvent are mixed and coated on a PE separator in the form of a slurry, and dried to provide thermal stability and mechanical properties of the PE separator. In order to improve, it has a coating thickness of 1 to 10 um.

In addition, polyvinyl alcohol is a polymer that is soluble in water, and is also referred to as a vinyl alcohol resin.

Polyvinyl alcohol has excellent film formation, emulsion, and adhesion properties, and does not mix with oil, lubricants, and solvents. When coated on a separator, the surface changes hydrophilicity, resulting in higher electrolyte permeability than before. Since the internal and external electrolytes can be circulated smoothly in the state of charging and discharging, it is possible to prevent the phenomenon of deteriorating the performance of the lead acid battery due to the partial use of the existing electrolyte.

Accordingly, the lead acid battery using the separator coated with the hydrophilic polymer of the present invention can improve basic performance and durability.

Thereafter, the hydrophilic polymer coating PE isolating plate completion step (S200) is a process for manufacturing a high-performance PE isolating plate through a drying process of the PE isolating plate including the prepared hydrophilic polymer coating layer.

That is, the PE separator with the hydrophilic polymer coating layer of the present invention is naturally dried for about 24 hours to manufacture a high-performance PE separator.

Basic performance and lifespan of a lead acid battery using a PE separator that does not include a general hydrophilic polymer coating layer and a lead acid battery using a PE separator including the hydrophilic polymer coating layer of the present invention to understand the effects of the present invention as described above. Although the test was conducted, a product with a final capacity of 80Ah was produced through subsequent processes such as assembly and chemical conversion, and a life test was conducted according to SAE J240 standard to verify the life at high temperature.

The conventional product to be described later refers to a lead acid battery using a PE separator that does not include a hydrophilic polymer coating layer manufactured by the applicant, and the improved product refers to a lead acid battery using a PE separator including a hydrophilic polymer coating layer.

As a result of the test, the capacity and lifespan of 87Ah in the holding capacity ended at 2,400 cycles, which was improved by 6% in the holding capacity and 25% in the lifespan compared to the conventional product.

Experimental data on this will be described later.

4 is a graph comparing an improved product manufactured by a high-performance PE separator manufacturing method through a hydrophilic polymer coating according to an embodiment of the present invention and a conventional product manufactured through a general manufacturing method, according to the standards of the American Automobile Engineers Association. This is a graph showing the lifespan in a high-temperature environment.

The test standard is a test method for measuring the cycle until the end of its life by repeatedly charging/discharging the EFB at a high temperature (75°C).

(1 cycle: 25A 4 minutes discharge, 14.8V [max 25A] constant voltage 10 minutes charge)

This test is repeated 480 times for 1 week, and then after standing for 56 hours, the state of the lead acid battery is determined by discharging at a high rate of 630A and measuring the voltage at the time point of 30 seconds.

If the voltage at the time of 30 seconds is more than 7.2V, the lead acid battery is judged as intact and the above cycle is repeated. If it is less than 7.2V, the lead acid battery is judged as the end of its life and the test is stopped.

<Test Example>

The conventional product described later refers to a lead acid battery using a general separator manufactured by the applicant, and the improved product refers to a lead acid battery using a PE separator including a hydrophilic polymer coating layer.

division Conventional product Improvement RC 118min 125min CCA 622A 640A C20 82Ah 87Ah Durability (SAE J240) 1,920 Cycle 2,400 Cycle

Table 1 is a performance test result of a conventional lead acid battery and a lead acid battery manufactured using the manufacturing method of the present invention, showing 1,920 cycles in the case of the conventional product with durability, and 2,400 cycles in the case of the improved product. See Fig. 4)

Therefore, it was confirmed through an experiment that the durability was improved by 25% compared to the conventional conventional product.

1) Reserve Capacity (RC)

Retention capacity RC measures the duration of discharge possible until the discharge end voltage reaches 10.5V with a discharge current of 25A at 25℃ after leaving for 1 hour or more after completion of full charge. It is a measure of how long the minimum function can be exerted to operate the load in a stopped state, etc.

As a result of the test, as shown in Table 1, in the case of manufacturing including the hydrophilic polymer coating layer according to the present invention, the holding capacity (RC) is 126 to 130 minutes, precisely 125 minutes, which is 6% of the conventional product. By showing the effect of improving the performance, it was found that the lead acid battery including the PE separator including the hydrophilic polymer coating layer had a positive effect on the storage capacity.

2) Low temperature starting current (CCA: Cold Cranking Ampere)

In general, the rapid discharge characteristics of a storage battery rapidly deteriorate below -10℃. The low-temperature starting current (CCA) is a high-rate discharge test for evaluating the starting capability of a vehicle at low temperatures. Measure the voltage at the time of super discharge.

In this test, the voltage at 30 seconds is required to be more than 7.2V, and the higher it is, the better the performance is evaluated.

In the present invention, the CCA was calculated using a correction formula of (30 second voltage ÷ 6-0.2) × 630.

As a result of the test, as shown in Table 1, the voltage for 30 seconds is 7.15V ~ 7.22V, and the converted CCA is 650A ~ 660A, and it is precisely 640A, showing a 4% performance improvement effect compared to the conventional product. It can be seen that the PE separator including, had a positive effect on the low-temperature starting current.

3) 20 hour rate capacity (AH)

This is to find out the low rate discharge characteristics, and measure the discharge capacity (AH) until the voltage reaches 10.5V by continuously discharging at 3.75A, which is a relatively small current with respect to the capacity of the lead acid battery.

As a result of the test, 85AH ~ 89AH, precisely 87AH, showed a 6% performance improvement effect compared to the existing product, so that the PE separator including the hydrophilic polymer coating layer had a positive effect on the 20 hour rate capacity (AH). And it was found.

4) Life verification test (SAE J240, Cycle)

As a graph (SAE J240) that verified the lifespan in a 75°C environment according to the standards of the American Association of Automobile Engineers, the test standard indicates the cycle until the end of the life of the lead acid battery by repeating charging/discharging at high temperature (75°C). It is a test method to measure.

(1 cycle: 25A 4 minutes discharge, 14.8V [max 25A] constant voltage 10 minutes charge)

This test is repeated 480 times for one week, and then, after standing for 56 hours, discharge at a high rate of 630A and measure the voltage at the time point of 30 seconds to determine the state of the lead acid battery.

If the voltage at the time of 30 seconds is more than 7.2V, the lead acid battery is judged as intact and the above cycle is repeated. If it is less than 7.2V, the lead acid battery is judged as the end of its life and the test is stopped.

As a result of the test, as shown in FIG. 4, it was found that the PE separator including the hydrophilic polymer coating layer had a positive effect on the increase of the lifespan by showing a 25% improvement in the lifespan compared to the conventional product.

5) Charge acceptance test (CA: Charge Acceptance test)

After discharging a fully charged sample for 2.5 hours at room temperature (25±2℃) with a 5-hour rate current (17.5A based on 70Ah), leave it at 0±2℃ for 12 hours or more.

After that, charge it with 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 electric conductivity and charging efficiency were high, and the current of the improved product increased by 32% in about 10 minutes compared to the conventional product (see Fig. 5).

division time Conventional product Improvement




Rechargeable income 1 min 27.25 28.17 2 minutes 24.21 26.98 3 minutes 22.14 26.22 4 minutes 21.25 25.52 5 minutes 20.11 24.83 6 minutes 19.35 23.94 7 minutes 18.74 23.46 8 minutes 17.68 22.79 9 minutes 17.04 22.37 10 minutes 16.43 21.78

Through the above manufacturing method, by coating a hydrophilic polymer material on the PE separator in order to uniformly form the hydrophilic polymer coating layer, the surface of the PE separator is changed to hydrophilicity, thereby improving the permeability of the electrolyte solution to the inside and outside the separator. By circulating in this charged and discharged state, the effect of improving the durability and performance of the lead acid battery is provided.

Those skilled in the art to which the present invention with the above contents pertains will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, the embodiments described above are exemplified in all respects and should be understood as non-limiting.

S100: Hydrophilic polymer coating PE isolation plate manufacturing step
S200: Hydrophilic polymer coating PE isolation plate completion stage

Claims (5)

In the method for manufacturing a PE separator of a lead acid battery, which is installed to prevent direct contact of electrodes of opposite polarities with each other
Contaminant removal step for removing contaminants from the surface of the PE separator; And
For surface modification, a pretreatment step for performing pretreatment using oxygen plasma; And
Hydrophilic polymer coating PE isolating plate manufacturing step (S100) for coating a hydrophilic polymer material on the PE isolating plate in order to uniformly form the hydrophilic polymer coating layer on the PE isolating plate; And
Including; a hydrophilic polymer coating PE isolating plate completion step (S200) for manufacturing a high-performance PE isolating plate through a drying process of the PE isolating plate containing the prepared hydrophilic polymer coating layer;
The pretreatment step,
Surface treatment by using an inert gas such as helium or argon instead of oxygen plasma to form a stable cross-linked layer by generating free radicals by being cut off by carbon-carbon bonds on the surface, ions in which carbon and hydrogen are bonded, or vacuum ultraviolet rays Characterized in that to proceed,
The hydrophilic polymer coating PE isolation plate manufacturing step (S100),
In the case of using the spin coating method to uniformly form the hydrophilic polymer coating layer on the PE separator, spin coating is performed at a rotation speed of 1,000 to 5,000 rpm, and after coating, drying at room temperature for 12 hours and then at 600°C in air 2 It is characterized in that pre-heat treatment (pre heat-treatment) for a period of time,
In order to improve the heat resistance of the PE separator, the coating, drying and preheating processes are repeated 3 to 5 times,
The hydrophilic polymer coating layer,
In order to improve the thermal stability and mechanical properties of the PE separator, it is characterized in that it is formed with a coating thickness of 1 to 10 um,
It is characterized in that by coating the hydrophilic polymer material, the surface of the PE separator is changed to hydrophilicity to improve the permeability of the electrolyte so that the electrolyte inside and outside the separator is circulated in a state of charge and discharge, thereby improving the durability of lead storage,
The hydrophilic polymer material,
It is characterized in that it is polyvinyl alcohol (PVA),
By the method of manufacturing a high-performance PE separator through the hydrophilic polymer coating,
When the manufactured lead acid battery has a capacity of 80Ah ~ 87Ah,
The lifetime is characterized by being able to provide durability improvement within the range of 20% to 25% from 2,304 to 2,400 cycles at 1,920 cycles,
The holding capacity (RC) is characterized by providing a 6% performance improvement from 118 minutes to 125 minutes,
Low temperature starting current (CCA) is characterized by providing a 4% performance improvement from 622A to 640A.
20 hour rate capacity (AH) is a high performance PE separator manufacturing method through a hydrophilic polymer coating, characterized in that it provides a 6% performance improvement from 82AH to 87AH.
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