KR102305189B1 - Method for manufacturing anode active material for lead-acid battery using schwarzite - Google Patents

Abstract

The present invention relates to a method for manufacturing a negative electrode active material for a lead-acid battery using Schwarzite. More specifically, the method includes adding Schwarzite to the active material added to the negative electrode of a conventional lead acid battery. Thus, it is possible to improve the electrolyte permeability in the electrode plate, increase the binding force of the active material, and expand the reaction area. Accordingly, by increasing the internal electrical conductivity of the negative electrode active material, it is possible to improve the basic performance of the lead-acid battery and the charging efficiency. In addition, according to the present invention, it is possible to improve the electrolyte permeability in the electrode plate, increase the binding force of the active material and expand the reaction area, thereby increasing the internal electrical conductivity of the negative electrode active material, thereby improving the basic performance and charging efficiency of the lead-acid battery.

Description

Method for manufacturing anode active material for lead-acid battery using schwarzite

The present invention relates to a method for manufacturing an anode active material for a lead acid battery using Schwarzite, and more particularly, by adding Schwarzite to an active material added to a conventional negative electrode of a lead acid battery, improving electrolyte permeability and increasing active material binding force and reaction It relates to a method for manufacturing an anode active material for a lead acid battery using Schwarzent, which can increase the internal electrical conductivity of the anode active material by increasing the area, thereby improving the basic performance and charging efficiency of the lead acid battery.

Currently, the active material mechanism for lead-acid batteries adds polyester-based fibers to the active material to secure physical strength and surface area for reaction with sulfuric acid.

Typically, a polyester-based fiber having a fineness of 0.8 to 5 denier and a length of 1 to 10 mm is added to the lead acid battery active material, and these fibers (fibers) have excellent acid resistance and oxidation resistance.

At this time, the organic synthetic short fibers to be added usually have a circular cross-section and have a length of about 2 to 10 mm.

The components of organic synthetic short fibers are mainly polypropylene, polyester, and modacrylic, which have excellent acid and oxidation resistance.

The prior art, Republic of Korea Patent Registration No. 10-0603908, "Electrode plate for storage battery and method for manufacturing the same" is a pole plate manufacturing by applying pressure to attach fiber-reinforced paper so that fiber filaments are embedded in the surface of the active material, and then filling the concavo-convex part of the surface with the active material. method is disclosed.

The above-mentioned prior Korean patent registration relates to "a electrode plate for a storage battery and a method for manufacturing the same". The electrode plate of a storage battery is coated with an active material having electrochemical activity on a substrate that serves as a passage for electricity to flow, and fiber-reinforced paper is applied to the surface of the active material. In the step of attaching or pressing, pressure is applied so that the fiber filaments of the fiber-reinforced paper are embedded to a certain depth, and the active material is filled in the surface irregularities of the fiber-reinforced paper to increase the binding surface area, thereby preventing the active material from being detached from the substrate. Technology to prevent and further improve the initial high-rate discharge characteristics of the electrode plate due to the porosity of the fiber-reinforced paper, and to extend the life of the storage battery by holding and supporting the active material due to the stable support and acid resistance of the fiber-filament structure of the fiber-reinforced paper is about

So far, lead (Pb)-calcium (Ca)-tin (Sn) alloys have been used as grid alloys for lead-acid batteries. It is pointed out as a problem that the lifespan of the lead-acid battery is shortened due to deformation due to the growth of the battery.

Accordingly, it is required to improve the corrosion resistance, mechanical strength, and suppress growth deformation of the grid.

On the other hand, the active material of a conventional lead-acid battery is generally based on lead powder and an aqueous sulfuric acid solution, and after mixing other additives according to the characteristics of the positive and negative electrodes, the active material is prepared.

The active material made in this way goes through a coating operation that is applied to the substrate, and after aging and drying according to the positive/negative characteristics, the prepared positive and negative plates are alternately overlapped in several sheets, and at this time, to prevent an electrical short between the plates. To this end, a non-conductive separator is installed, and the positive plate, the negative plate, and the separator are configured to form an electrode plate group.

A plurality of electrode plate groups are connected in series according to the capacity of the battery and are accommodated in the electric wire.

The accommodated electrode plate group undergoes a chemical conversion process that is supercharged so that it can have electrical properties. At this time, lead dioxide (PbO2) is formed in the active material of the positive electrode plate, and due to its characteristics, countless fine particles of oxidized lead are combined, and the porosity is abundant, so that the particles The electrolyte is designed to freely diffuse and penetrate the liver.

In addition, the active material of the negative plate is spongy lead (Pb), which is also rich in porosity and reactivity so that the electrolyte can freely diffuse and penetrate.

The products made in this way are finally available for use in the market.

In addition, in order to facilitate the supercharging process and improve the durability of the product, a separate aging and drying process is performed for each polarity.

The aging process of the positive electrode plate is an important process to increase the durability of the product. Lead (Pb), a component of the active material, is converted into lead oxide ( PbO) as well as change the crystal structure of the active material.

If the negative plate is left in its natural state without a separate process, it can be aged and dried at the same time.

However, if sufficient aging and drying are not performed, the electrode plate and the electrode plate stick to each other during the assembly process to form the electrode plate group, and the durability of the active material is reduced due to the presence of moisture, and the active material embedded between the substrates is easily dropped even by a small impact.

In the lead-acid battery made through this process, as the number of charging and discharging increases, the active material is more easily removed from the substrate by the reaction of lead and sulfuric acid, and the dropped active material cannot participate in the reaction any longer, so eventually the lead-acid battery By lowering the performance, the lifespan of lead-acid batteries is usually only 1 to 2 years.

Therefore, in accordance with the current demand for high-performance lead-acid batteries, a manufacturing process capable of improving the durability and performance of lead-acid batteries is required.

As a prior art, 'anode active material, manufacturing method thereof, and lead-acid battery' has disclosed a technique for a negative active material characterized in that lignin is added to lead powder.

However, it was difficult to expect the effect of improving the lifespan of the active material in the above technique.

Korean Patent Registration No. 10-0483246

Accordingly, the present invention has been devised to solve the above problems of the prior art,

An object of the present invention is to improve the electrolyte permeability in the electrode plate, increase the binding force of the active material, and expand the reaction area by adding Schwarzite to the active material added to the negative electrode of the conventional lead acid battery, thereby increasing the internal electrical conductivity of the negative electrode active material. An object of the present invention is to provide a method for manufacturing an anode active material for a lead-acid battery using Schwarzent that can improve the basic performance and charging efficiency of the battery.

In order to achieve the problem to be solved by the present invention, a method for manufacturing a negative active material for a lead-acid battery using Schwarzite according to an embodiment of the present invention,

In the negative active material mixing process of the lead acid battery,

In the negative active material mixing process of the lead acid battery,

When mixing smoke, sulfuric acid, and additives according to the negative electrode, a Schwarzite mixing step (S100) for adding and mixing Schwarzite powder and distributing it in the negative electrode active material; and

By including a natural aging and drying step (S200) for naturally aging and drying in the atmosphere after applying the negative active material containing Schwarzite to a substrate made of lead, the problem of the present invention is solved.

Through the method of manufacturing an anode active material for a lead-acid battery using Schwarzite according to the present invention, by using Schwarzite as an additive in the active material, it is possible to improve the electrolyte permeability in the electrode plate, increase the binding force of the active material, and expand the reaction area. By increasing the internal electrical conductivity of the lead-acid battery, it provides the effect of improving the basic performance and charging efficiency of the lead-acid battery.

Specifically, the addition of Schwarzite provides the effect of increasing the basic performance and charging efficiency of the lead-acid battery by activating pores and increasing the reaction area with sulfuric acid and internal electrical conductivity of the anode active material.

1 is a process diagram of a method for manufacturing an anode active material for a lead acid battery using Schwarzite according to an embodiment of the present invention.
2 is a photograph showing the Schwarzite included in the present invention.
3 is an exemplary view showing various types of carbon allotropes.

A method for manufacturing an anode active material for a lead acid battery using Schwarzite according to an embodiment of the present invention,

In the negative active material mixing process of the lead acid battery,

When mixing smoke, sulfuric acid, and additives according to the negative electrode, a Schwarzite mixing step (S100) for adding and mixing Schwarzite powder and distributing it in the negative electrode active material; and

It is characterized in that it comprises a; natural aging and drying step (S200) for naturally aging and drying in the air after applying the negative active material containing Schwarzenite to the substrate made of lead.

At this time, the content of Schwarzite in the negative active material is,

It is characterized in that 0.1 to 10 parts by weight are added based on 100 parts by weight of the negative active material excluding Schwarzite.

At this time, in the Schwarzite mixing step (S100),

It is characterized in that the basic performance and charging efficiency of the lead-acid battery are increased by adding Schwarzite powder to activate pores and increase the reaction area with sulfuric acid and increase the internal electrical conductivity of the anode active material.

At this time, by the method for producing a negative active material for a lead-acid battery using the Schwarzite,

It is characterized in that it can provide a lifespan improvement of 28.5% with a lifespan of 306 cycles with the addition of Schwarzite powder from 238 cycles, which is a lifespan without the addition of Schwarzite powder.

At this time, by the method for manufacturing a negative active material for a lead acid battery using Schwarzite of the present invention, it is possible to provide a lead storage battery including an electrode plate for a lead storage battery to which a negative active material for a lead storage battery using Schwarzite is applied.

Hereinafter, a method for manufacturing a negative active material for a lead-acid battery using Schwarzite according to the present invention will be described in detail through an embodiment.

1 is a process diagram of a method for manufacturing an anode active material for a lead acid battery using Schwarzite according to an embodiment of the present invention.

As shown in FIG. 1, the method for manufacturing a negative active material for a lead acid battery using Schwarzite of the present invention is,

In the negative active material mixing process of the lead acid battery,

When mixing smoke, sulfuric acid, and additives according to the negative electrode, a Schwarzite mixing step (S100) for adding and mixing Schwarzite powder and distributing it in the negative electrode active material; and

After the anode active material containing Schwarzite is applied to a substrate made of lead, a natural aging and drying step (S200) for natural aging and drying in the air (S200); will be included.

The present invention relates to a method for manufacturing an anode active material for a lead-acid battery using Schwarzite, and uses Schwarzite instead of a polyester-based fiber used in the prior art to increase the internal electrical conductivity of the anode active material, thereby improving the basic performance and charging of a lead-acid battery This is to improve efficiency.

As shown in FIG. 2, the schwarzite described in the present invention has a structure in which carbon is disposed on a porous support called zeolite, and is produced by growing a carbon film on the surface of the zeolite using a catalyst. .

As shown in FIG. 2, schwarzite facilitates the penetration of the electrolyte to the inside of the electrode plate due to its hollow shape, thereby expanding the electrical reaction area, and the binding force of the active material is improved compared to the conventional fibers, resulting in high output and life expectancy. can be improved.

That is, when schwarzite is added, the contact area with the electrolyte is enlarged compared to the conventional fiber according to the hollow shape of schwarzite, and the electrolyte permeability in the electrode plate is improved and the binding force of the active material is increased. It becomes possible to improve the electrical conductivity in the active material and the ability to accept electrons by utilizing the high electrical conductivity.

As a result, it was confirmed through an experiment that it was possible to improve the efficiency of the active material and to improve the charging importability.

In addition, the cause of failure of a lead acid battery depends on the type of load and how it is managed during use.

The main failure factors include sulfated active material, dislodged electrode plate active material, positive electrode grid corrosion, separator breakage, and complex factors.

In particular, in the case of products mounted on automobiles, the active material sulphation is accelerated depending on the operating conditions and the load used in the electric field, and the electrode plate active material falls off, resulting in an early end of life.

Therefore, it is important to increase the reaction area of the active material of the electrode, and it is important to increase the elongation rate to increase the adhesion between the active materials.

In conclusion, by introducing schwarzite, electrical conductivity and elongation were increased to increase adhesion between active materials, thereby improving sulfation delay and deactivation of active materials, which are major causes of end-of-life.

In order to provide the above functions, the Schwarzite mixing step (S100) of the present invention comprises adding and mixing Schwarzite powder when mixing smoke, sulfuric acid, and additives according to the negative electrode to distribute it in the negative electrode active material. is a step

In order to provide the effect of the present invention, the content of Schwarzite in the negative active material is,

It is characterized in that 0.1 to 10 parts by weight are added based on 100 parts by weight of the negative active material excluding Schwarzite,

Specifically, the Schwarzite mixing step (S100) is,

A basic negative active material mixing step of mixing 80 to 83 parts by weight of smoke, 5 to 10 parts by weight of sulfuric acid, 10 to 15 parts by weight of water, and 1 to 3 parts by weight of a negative electrode additive based on the total weight of the negative active material; and

To the mixture formulated in the basic negative electrode active material mixing step, 0.6 to 0.9 parts by weight of Schwarzite powder based on the total weight of the mixture is added and stirred at a temperature of 55 to 75 degrees to obtain a negative active material having a density of 75 to 80 g/in3. It will include a step of obtaining a negative electrode active material added

When the weight of the added Schwarzite powder is less than 0.6 parts by weight, the electrical conductivity of the electrode plate is similar to that of the prior art, so it is difficult to expect performance improvement. , it is difficult to expect more than a cycle of 0.6 parts by weight of the life cycle, and only provides a cause for price increase.

Therefore, it would be preferable to add the Schwarzite powder within the above range.

Sulfation of the active material described in the present invention _{refers to a phenomenon in which the electrode plate is crystallized with lead sulfate (PbSO 4} ), and when the lead-acid battery repeatedly charges and discharges, the electrode plate is covered with an inert material.

The main causes are repeated use of charging and discharging for a long period of time, over-discharging, when left in a discharged state for a long time, when the specific gravity of the electrolyte is too low, when the electrode plate is exposed due to lack of electrolyte, and impurities in the electrolyte. When this is mixed, it is a case where insufficient charging is repeated, etc.

On the other hand, electrode plate manufacturing for lead-acid batteries generally includes paste mixing, aging, and drying processes, and in these operations, the active material in the electrode plate undergoes physical and chemical changes to establish an electrochemical mechanism and mechanical strength.

In lead-acid battery negative plates, paste with expander added is generally used, and lignin, sodium sulfate, and carbon black are used as components of the expander.

Among these components, carbon black is added to improve electrical conductivity.

As shown in FIG. 3 , types of carbon allotropes having electrical conductivity include graphene, carbon nanotube (CNT), fullerene, graphite, schwarzite, and the like.

The component of the pencil lead we usually use is called graphite, and the structure in which only one layer of graphite is removed is called graphene, and when this graphene is rolled into a cylindrical shape, it is called carbon nanotube (CNT). call

Fullerene is a hollow structure in which carbon atoms are arranged in the shape of a soccer ball.

In particular, a carbon structure having a negative (-) curvature by properly disposing carbon on a porous support called zeolite is called Schwarzite.

Zeolite as a support refers to a silicate porous mineral.

It is usually used as a deodorant and a purifier, and in the R&D field, it is also used as a support for metal and organic catalysts.

In the case of zeolite, there are numerous nanometer-diameter holes, so the specific surface area is very high.

Carbon black, which is commonly used, has a specific surface area of 50 to 200 m ² /g, whereas Schwarzite has a specific surface area of ^{2000 to 4000 m 2 /g.}

At this time, in order to expect the electrical conductivity effect of carbon black, as many conductive materials as possible should be included in the same capacity.

Therefore, when Schwarzite, which has a specific surface area about 10 to 80 times higher than that of carbon black, is mixed with an equal weight, excellent electrical conductivity is improved.

After all, the present invention is a lead-acid battery through pore activation, reaction area with sulfuric acid, and electrical conductivity by adding Schwarzite, one of the carbon structures with an increased specific surface area than carbon black, to the lead-acid battery negative plate active material to improve electrical conductivity of battery capacity and DoD durability.

In addition, the natural aging and drying step ( S200 ) is a process of applying a negative active material containing Schwarzite to a substrate made of lead, followed by natural aging and drying in the air.

That is, after a certain amount of the anode active material containing high-conductivity Schwarzite is evenly spread on a substrate made of lead, it is naturally aged and dried in the air for 2 to 3 days.

As described above, in order to grasp the effect of the present invention, when mixing the active material, the organic synthetic short fibers that were previously injected were replaced with high-conductive Schwarzite and added in the same weight ratio to produce a pole plate and aged through the aging process, then the foundation Performance and life tests were performed.

The conventional product described below refers to a product manufactured using a negative electrode plate coated with organic synthetic short fibers in the active material used in the lead-acid battery (BX80) manufactured by the applicant, and the improved product is through the manufacturing method of the present invention. Refers to a product containing a lead-acid battery electrode plate to which high-conductivity Schwarzent is applied.

In addition, conventional products (including organic synthetic short fibers) and improved products (high-conductivity Schwarzent) with a final 70 Ah capacity (20 hour rate capacity) through processes such as assembly and chemical conversion to give electrical conductivity to the substrate included), and a 50% DoD durability test was performed to prove the effect of high-conductivity Schwarzite.

1) CA: Charge Acceptance test

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

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 improved product increased the current by 15% in about 10 minutes compared to the conventional product due to high battery conductivity and charging efficiency.

division hour conventional products improvement




chargeability 1 minute 27.25 28.17 2 minutes 24.21 25.38 3 minutes 22.14 23.83 4 minutes 21.25 22.92 5 minutes 20.11 21.83 6 minutes 19.35 20.84 7 minutes 18.74 19.16 8 minutes 17.68 18.39 9 minutes 17.04 18.67 10 minutes 16.43 18.89

The organic synthetic short fibers are added to the active material for the purpose of increasing the mechanical strength of the battery active material.

As for the material, polypropylene, polyester, and modacrylic series are used in consideration of acid resistance to an aqueous sulfuric acid solution, which is an electrolyte.

The organic synthetic short fibers used have a circular cross section, which is the specification of conventional synthetic short fibers produced by direct spinning, have a fineness of 2 to 5 denier (diameter is about 12 to 20 micrometers), and have a length of 2 to is 10 millimeters.

The amount added during mixing is 0.1 to 0.5 wt%, which improves the mechanical strength of the final electrode active material, thereby suppressing the destruction of the structure of the active material due to contraction and expansion of the active material due to vibration and charging/discharging.

However, in the case of the organic synthetic short fibers, there is a problem in providing performance in an environment that requires increasingly high basic performance.

Therefore, in the present invention, in order to improve this, a high-conductivity Schwarzite having excellent electrical conductivity is used.

As shown in FIG. 2, the high-conductivity Schwarzite increases the electrical reaction area by facilitating the penetration of the electrolyte to the inside of the electrode plate due to its hollow shape, and by increasing the pore activation and reaction area with sulfuric acid compared to the conventional fiber, high output and It is possible to bring about an improvement in the life expectancy, and ultimately, the basic performance and lifespan of the battery are improved.

Therefore, the high-conductivity Schwarzite having the above characteristics was introduced in the present invention, and by using the high-conductivity Schwarzite as an additive in the negative active material, the effect of maximizing the reaction area of the active material and increasing the electrical conductivity is provided. will do

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 75°C water bath for about one week, similar to general vehicle conditions.

After performing 34 cycles, discharge at 200A for 10 seconds and when it maintains 7.2V or higher, proceed with the life test in such a way that the cycle is repeated 34 times.

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

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

cycle Schwarzite 0 parts by weight Schwarzite 0.3 parts by weight Schwarzite 0.6 parts by weight Schwarzite 0.9 parts by weight Schwarzite 1.2 parts by weight 34 11.82 11.83 11.85 11.87 11.89 68 11.76 11.77 11.80 11.83 11.87 102 11.72 11.73 11.78 11.80 11.84 136 11.69 11.71 11.76 11.79 11.82 170 11.65 11.68 11.74 11.77 11.80 204 11.55 11.61 11.69 11.70 11.76 238 11.43 11.45 11.60 11.63 11.70 272 7.2 or less 7.2 or less 11.49 11.55 11.65 306 7.2 or less 11.50 11.55 340 7.2 or less 7.2 or less

As shown in Table 2, the test results show that the lifespan is 238 cycles when high-conductivity Schwarzite is not added and when 0.3 parts by weight is added, but when 0.6 parts by weight is added, the lifespan is 272 cycles, and when 0.9 parts by weight is added, the lifespan is 238 cycles. Life is now capable of providing a 28.5% life improvement at 306 cycles.

However, it can be seen that the lifespan does not further increase at 306 cycles even when the high-conductivity Schwarzite is added in excess of 0.9 parts by weight. Accordingly, the most optimal range from 0 parts by weight to 10 parts by weight is 0.6 to 0.9 parts by weight. Therefore, it is preferable to add within the above range.

This is seen as a result of the decrease in the amount of sulfate accumulated in the active material as the charging efficiency is increased because the electrical conductivity between the active materials is improved, the electrical resistance is lowered, and the reaction surface area is increased.

That is, by showing a 28.5% improvement in lifespan compared to conventional products, it was found that the addition of high-conductivity Schwarzite had a positive effect on the increase in lifespan.

Through the above-described manufacturing method, the addition of Schwarzite activates pores and increases the reaction area with sulfuric acid, and increases the internal electrical conductivity of the negative active material, thereby providing the effect of increasing the basic performance and charging efficiency of the lead-acid battery.

Those skilled in the art to which the present invention of the above contents pertain will be able to understand that the present invention may be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all aspects and not restrictive.

S100: Schwarzite mixing step
S200: Natural aging and drying stage

Claims (5)

In the method for producing a negative active material for a lead-acid battery using Schwarzent,
In the negative active material mixing process of the lead acid battery,
When mixing smoke, sulfuric acid, and additives according to the negative electrode, a Schwarzite mixing step (S100) for adding and mixing Schwarzite powder and distributing it in the negative electrode active material; and
After applying the anode active material containing Schwarzite to the substrate made of lead, natural aging and drying step (S200) for natural aging and drying in the atmosphere; characterized in that it comprises;
In the Schwarzite mixing step (S100),
It is characterized in that the basic performance and charging efficiency of lead-acid batteries are increased by adding Schwarzite powder to activate pores and increase the reaction area with sulfuric acid, and increase the internal electrical conductivity of the negative electrode active material,
It is characterized in that it can provide a lifespan improvement of 28.5% with a lifespan of 306 cycles when the Schwarzite powder is added from 238 cycles, which is a lifespan without the addition of Schwarzite powder,
It is characterized in that the chargeability is increased by 15% from 16.43A to 18.89A,
The Schwarzite mixing step (S100) is,
A basic negative active material mixing step of mixing 80 to 83 parts by weight of smoke, 5 to 10 parts by weight of sulfuric acid, 10 to 15 parts by weight of water, and 1 to 3 parts by weight of a negative electrode additive based on the total weight of the negative active material; and
To the mixture formulated in the basic negative electrode active material mixing step, 0.6 to 0.9 parts by weight of Schwarzite powder based on the total weight of the mixture is added and stirred at a temperature of 55 to 75 degrees to obtain a negative active material having a density of 75 to 80 g/in3. A method for producing an anode active material for a lead-acid battery using Schwarzite, characterized in that it comprises;

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