KR102225186B1 - Method for manufacturing anode active material for lead-acid battery using hollow spiral carbon fiber - Google Patents

Abstract

The present invention relates to a method of manufacturing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber, and more particularly, by adding a hollow spiral carbon fiber to an active material added to a conventional lead acid battery negative electrode, the electrolyte permeability in the electrode plate is improved and the active material binding force is increased. And a method for manufacturing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber capable of improving basic performance and charging efficiency of a lead storage battery by increasing the internal electrical conductivity of the negative electrode active material by increasing the reaction area.
Through the present invention, by using a hollow spiral carbon fiber as an additive to 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. It provides an effect that can improve the overcharging efficiency.

Description

Method for manufacturing anode active material for lead-acid battery using hollow spiral carbon fiber

The present invention relates to a method of manufacturing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber, and more particularly, by adding a hollow spiral carbon fiber to an active material added to a conventional lead acid battery negative electrode, the electrolyte permeability in the electrode plate is improved and the active material binding force is increased. And a method for manufacturing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber capable of improving basic performance and charging efficiency of a lead storage battery by increasing the internal electrical conductivity of the negative electrode active material by increasing the reaction area.

The current lead acid battery active material mechanism is adding polyester-based fibers to the active material to secure physical strength and a reaction surface area with sulfuric acid.

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

At this time, the added short organic synthetic fibers generally have a circular cross-sectional shape, and the length is about 2 to 10 mm.

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

In the related art of Korean Patent Registration No. 10-0603908, "electrode plate for storage battery and its manufacturing method", the electrode plate is manufactured by attaching fiber-reinforced paper by applying pressure so that the fiber filaments are stuck on the surface of the active material and filling the active material in the irregularities of the surface. Initiate the method.

The above-described conventional Korean registered patent relates to "electrode plate for storage battery and its manufacturing method". The electrode plate of the storage battery is coated with an active material having an electrochemical activity on a substrate serving as a passage through which electricity flows, 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 fibrous filaments of the fibrous reinforced paper are stuck to a certain depth, and the active material is filled in the uneven surface of the fibrous reinforced paper to increase the binding surface area, thereby preventing the active material from detaching from the substrate. In addition, technology that improves the initial high-rate discharge characteristics of the electrode plate due to the porosity of the fiber-reinforced paper, and also extends the life of the battery by holding and supporting the active material due to the stable support and acid resistance of the fibrous filament structure of the fiber-reinforced paper. It is about.

Until now, lead (Pb)-calcium (Ca)-tin (Sn)-based alloys have been used as grid alloys for lead-acid batteries, but this alloy composition alone cannot adequately cope with the harsh environment (high temperature and overcharging phenomenon), so the grid is corroded or corroded. It has been pointed out as a problem that the life of the lead acid battery is shortened due to deformation caused by the growth of the battery.

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

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 other additives are mixed according to the characteristics of the positive electrode and the negative electrode, and then mixed to make an active material.

The active material thus made is applied to the substrate, undergoes a aging process and a drying process according to the characteristics of the positive and negative electrodes, and then alternately overlaps the prepared positive and negative plates, and at this time, to prevent an electrical short between the electrode plates. For this purpose, a non-conductive separator is installed, and a positive electrode plate, a negative electrode plate, and a separator are configured to form an electrode plate group.

According to the capacity of the storage battery, several electrode plate groups are connected in series and are accommodated in the roll box.

The accommodated electrode plate group undergoes a supercharged chemical conversion process to 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, numerous particles of oxidized lead are combined and the porosity is abundant. The electrolyte is freely diffused and penetrated into the liver.

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

The product made in this way can be used in the market.

In addition, in order to facilitate the supercharge process and improve the durability of the product, separate aging and drying processes are performed for each polarity.

The aging process of the positive electrode plate is an important process to increase the durability of the product, and lead (Pb), a constituent of the active material, is converted into lead (Pb) as a component of the active material at the hot temperature (about 70 ~ 100℃) and moisture (humidity of 99%) of steam. PbO), but also changes the crystal structure of the active material.

The negative electrode plate can be aged and dried at the same time if it is left in its natural state without any separate process.

However, if sufficient aging and drying are not performed, the electrode plate and the electrode plate adhere to each other in the assembly process of forming the electrode plate group, and the durability of the active material decreases due to the presence of moisture, so that the active material embedded between the substrates easily falls even under a small impact.

As the number of times of charge and discharge increases, the active material falls more easily from the substrate by the reaction of lead and sulfuric acid, and the fallen active materials can no longer participate in the reaction. By degrading the performance, the life of the lead acid battery is usually only 1 to 2 years.

Accordingly, there is a demand for a manufacturing process capable of improving the durability and performance of the lead storage battery.

As a conventional technique, the'cathode active material and its manufacturing method and lead acid battery' has disclosed a technique related to a negative electrode active material, characterized in that lignin is added to lead powder.

However, it was difficult to expect the above technology to have an effect of improving the life of the active material.

Korean Patent Registration No. 10-0483246

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

By adding hollow spiral carbon fiber to the active material added to the anode of the conventional lead acid battery, it is intended to improve 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 anode active material, basic performance and charging of lead storage batteries An object of the present invention is to provide a method for manufacturing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber capable of improving efficiency.

In order to achieve the problem to be solved by the present invention, a method of manufacturing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber according to an embodiment of the present invention,

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

When blending lead powder, sulfuric acid, and additives for the negative electrode, a hollow spiral carbon fiber mixing step (S100) for adding and mixing a hollow spiral carbon fiber to distribute it in the negative electrode active material; And

After applying the negative electrode active material containing the hollow spiral carbon fiber to a substrate made of lead, natural aging and drying step (S200) for naturally aging and drying in the air, thereby solving the problem of the present invention.

Through the method of manufacturing a negative electrode active material for a lead acid battery using graphene balls according to the present invention, by using a hollow spiral carbon fiber as an additive to 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 active material, it provides the effect of improving the basic performance and charging efficiency of the lead storage battery.

1 is a flowchart of a method of manufacturing a negative active material for a lead acid battery using a hollow spiral carbon fiber according to an embodiment of the present invention.
2 is a photograph showing a hollow spiral carbon fiber included in the present invention.

A method for manufacturing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber according to an embodiment of the present invention,

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

When blending lead powder, sulfuric acid, and additives for the negative electrode, a hollow spiral carbon fiber mixing step (S100) for adding and mixing a hollow spiral carbon fiber to distribute it in the negative electrode active material; And

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

At this time, the content of the hollow spiral carbon fiber in the negative active material,

It is characterized by adding 0.6 to 0.9 parts by weight based on 100 parts by weight of the negative electrode active material excluding the hollow spiral carbon fiber.

At this time, in the hollow spiral carbon fiber mixing step (S100),

It is characterized in that the addition of a hollow spiral carbon fiber increases the internal electrical conductivity of the negative electrode active material to increase the basic performance and charging efficiency of the lead acid battery.

At this time, by the method of manufacturing a negative electrode active material for a lead acid battery using the hollow spiral carbon fiber,

It is characterized in that the lifespan of the hollow spiral carbon fiber is 374 cycles when the hollow spiral carbon fiber is added in the lifespan of 238 cycles without the addition of the hollow spiral carbon fiber, which can provide 57% improvement in life.

In addition, by the production method of the present invention,

It is possible to provide a lead-acid battery including an electrode plate for a lead-acid battery to which a negative electrode active material for a lead-acid battery using a hollow spiral carbon fiber is applied.

Hereinafter, it will be described in detail through an embodiment of a method for manufacturing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber according to the present invention.

1 is a flowchart of a method of manufacturing a negative active material for a lead acid battery using a hollow spiral carbon fiber according to an embodiment of the present invention.

As shown in Fig. 1, the method of manufacturing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber according to the present invention,

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

When blending lead powder, sulfuric acid, and additives for the negative electrode, a hollow spiral carbon fiber mixing step (S100) for adding and mixing a hollow spiral carbon fiber to distribute it in the negative electrode active material; And

After applying the negative electrode active material containing the hollow spiral carbon fiber to a substrate made of lead, natural aging and drying step (S200) for naturally aging and drying in the atmosphere; and.

The present invention relates to a method for manufacturing an anode active material for a lead acid battery using a hollow spiral carbon fiber, and by using a hollow spiral carbon fiber instead of a conventional polyester fiber to increase the internal electrical conductivity of the anode active material, basic performance of a lead storage battery It is to improve the overcharging efficiency.

As shown in Fig. 2, the hollow spiral carbon fiber facilitates penetration of the electrolyte into the inside of the electrode plate due to its hollow shape to expand the electrical reaction area, and the binding force of the active material by the spiral is improved than that of the conventional fiber, resulting in high output and expectations. It is possible to improve the lifespan.

In other words, when the hollow spiral fiber is added, the contact area with the electrolyte is increased compared to the conventional fiber according to the hollow shape of the hollow spiral fiber, and the penetration of the electrolyte in the electrode plate and the active material bonding increase are provided. It is possible to improve the electrical conductivity in the active material and improve the ability to accept electrons.

As a result, it was confirmed through an experiment that the efficiency of the active material can be improved and the charging acceptance can be improved.

In addition, the cause of failure of a lead acid battery depends on the type of load and management method during use.

The main failure factors include active material sulphation, electrode plate active material dropout, anode grid corrosion, separator breakage, and complex factors.

In particular, in the case of a product mounted on a vehicle, the sulphation of the active material is accelerated according to the operating conditions and the use load on the electric field, and the electrode plate active material is dropped out, resulting in an early end of life.

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

In conclusion, the introduction of the hollow spiral carbon fiber improves the electrical conductivity and increases the elongation, thereby increasing the adhesion between the active materials, thereby improving the active material sulfation delay and activation problems, which are the main causes of the end of life.

In order to provide the above functions, in the hollow spiral carbon fiber mixing step (S100) of the present invention, when mixing lead powder, sulfuric acid, and additives according to the negative electrode, a hollow spiral carbon fiber is added and mixed to be distributed in the negative electrode active material. It is a step to do.

In order to provide the effect of the present invention, the content of the hollow spiral carbon fiber in the negative electrode active material,

It is characterized in that 0.6 to 0.9 parts by weight are added relative to 100 parts by weight of the negative electrode active material excluding the hollow spiral carbon fiber.

Specifically, the hollow spiral carbon fiber mixing step (S100),

Basic anode active material mixing step (S110) of mixing 80 to 83 parts by weight of lead powder, 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 an anode additive based on the total weight part of the anode active material; And

Hollow spiral type for obtaining a negative active material having a density of 75 to 80 g/in3 by adding 0.6 to 0.9 parts by weight of hollow spiral carbon fiber to the mixture blended in the basic cathode active material mixing step relative to the total weight of the mixture and stirring at a temperature of 55 to 75 degrees It includes; carbon fiber-added negative electrode active material acquisition step (S120).

When the weight part of the hollow spiral carbon fiber to be added 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 a small amount that it is difficult to expect performance improvement, and when it exceeds 0.6 parts by weight, as proved in the accelerated life test. However, it is difficult to expect more than 0.6 parts by weight of the life cycle, and it only provides a reason for the price increase.

Therefore, it would be desirable to add a hollow spiral carbon fiber within the above range.

The active material sulfation described in the present invention _{refers to a phenomenon in which the electrode plate becomes crystallized from lead sulfate (PbSO 4} ), and the electrode plate is covered with an inert material when the lead acid battery is repeatedly charged and discharged.

The main causes include repeated use of charging and discharging for a long period of time, over-discharge, long-term discharging, too low specific gravity of the electrolyte, exposure of the electrode plate due to insufficient electrolyte, and impurities in the electrolyte. When this is mixed, when insufficient charging is repeated, etc.

In addition, the natural aging and drying step (S200) is a step for naturally aging and drying in the atmosphere after applying the negative active material including the hollow spiral carbon fiber to a substrate made of lead.

That is, after a certain amount of the negative electrode active material including the highly conductive hollow spiral carbon fiber is spread evenly 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 previously introduced short organic synthetic fiber is replaced with a hollow spiral carbon fiber and added at the same weight ratio to prepare an electrode plate, and then aged through the aging process. Performance and life tests were performed.

The conventional product to be described later refers to a product manufactured by using a negative electrode plate coated after including organic synthetic staple fibers in an active material used in a lead acid battery (BX80) manufactured by the applicant. It refers to a product that includes a lead acid battery electrode plate to which a hollow spiral carbon fiber is applied.

In addition, conventional products (including organic synthetic staple fibers) and improved products (hollow spiral carbon fiber) with a final 70 Ah capacity (20 hour capacity) through subsequent processes such as assembly and chemical conversion that impart electrical conductivity to the substrate. Included), and a 50% DoD durability test was conducted to prove the effect of the hollow spiral carbon fiber.

1) 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 current of the improved product increased by 32% in about 10 minutes compared to the conventional product due to the high battery conductivity and charging efficiency.

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

Organic synthetic staple fibers are added to the active material for the purpose of increasing the mechanical strength of the battery active material.

As the material, polypropylene, polyester, and modacrylic 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 manufactured by direct spinning, and have a fineness of 2 to 5 denier (diameter is about 12 to 20 micrometers), and the length is 2 to It is 10 millimeters.

The amount added during mixing is 0.1 ~ 0.5 wt%, thereby improving the mechanical strength of the final electrode active material, thereby suppressing the destruction of the active material structure due to contraction and expansion of the active material due to vibration and charge/discharge.

However, in the case of the organic synthetic staple fibers, a problem arises in providing performance in an environment requiring increasingly high basic performance.

Accordingly, in the present invention, in order to improve this, a hollow spiral carbon fiber having excellent electrical conductivity is used.

As shown in FIG. 2, the hollow spiral carbon fiber increases the electrical reaction area by facilitating the immersion of the electrolyte to the inside of the electrode plate due to the hollow shape, and increases the high output and life expectancy because the bonding force of the active material by the spiral is higher than that of the conventional fiber. And finally improve the basic performance and lifespan of the battery.

Therefore, the hollow spiral carbon fiber having the above characteristics was introduced in the present invention, and by using the hollow spiral carbon fiber as an additive to the negative electrode active material, the effect of maximizing the reaction area of the active material and increasing the electrical conductivity is provided. .

Experimental data on this will be described later.

2) Accelerated life test (SAE J2801)

The lead acid battery is charged/discharged in a 75°C water bath for about a week, similar to general vehicle conditions, and undergoes 34 charge/discharge cycles.

After 34 cycles, discharge at 200A for 10 seconds, and if it is maintained above 7.2V, the life test is carried out again by conducting 34 cycles.

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

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

cycle Hollow spiral carbon fiber 0 parts by weight Hollow spiral carbon fiber 0.3 parts by weight Hollow spiral carbon fiber 0.6 parts by weight 0.9 parts by weight of hollow spiral carbon fiber Hollow spiral carbon fiber 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 11.48 11.56 340 11.40 11.45 374 11.31 11.35 408 7.2 or less 7.2 or less

As shown in Table 2, the test results show that when the hollow spiral carbon fiber is not added and when 0.3 parts by weight is added, the life is 238 cycles, but when 0.6 parts by weight is added, the life is 272 cycles, and when 0.9 parts by weight is added, the life is Is now able to provide a 57% lifetime improvement with 374 cycles.

However, even if the hollow spiral carbon fiber exceeding 0.9 parts by weight is added, the lifespan does not increase further at 374 cycles, and accordingly, the most optimal range is set to 0.6 to 0.9 parts by weight.

This is seen as a result of an increase in electrical conductivity between active materials, a decrease in electrical resistance, and an increase in reaction surface area, resulting in a decrease in the amount of sulfate accumulated in the active material as the charging efficiency increases.

That is, it was found that the addition of the hollow spiral carbon fiber had a positive effect on the increase of the lifespan by showing a 57% improvement in the lifespan compared to the conventional product.

Through the above manufacturing method, by using a hollow spiral carbon fiber as an additive to 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, thereby increasing the internal electrical conductivity of the negative electrode active material. It provides an effect that can improve the basic performance and charging efficiency of the storage battery.

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: Hollow spiral carbon fiber mixing step
S200: Natural ripening and drying stage

Claims (5)

In the method for producing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber,
In the negative electrode active material mixing process of lead acid battery,
When mixing the additives for the lead, sulfuric acid, and the negative electrode, a hollow spiral carbon fiber mixing step (S100) for adding and mixing a hollow spiral carbon fiber to distribute it in the negative electrode active material; And
Characterized in that it comprises a; after applying the negative electrode active material containing the hollow spiral carbon fiber to a substrate made of lead, natural aging and drying step (S200) for naturally aging and drying in the atmosphere, but,
The hollow spiral carbon fiber mixing step (S100),
Basic cathode active material mixing step (S110) of mixing 80 to 83 parts by weight of lead powder, 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 an anode additive based on the total weight part of the anode active material; And
Hollow spiral type for obtaining a negative active material having a density of 75 to 80 g/in3 by adding 0.6 to 0.9 parts by weight of hollow spiral carbon fiber to the mixture blended in the basic cathode active material mixing step relative to the total weight of the mixture and stirring at a temperature of 55 to 75 degrees It characterized in that it comprises a; carbon fiber added negative electrode active material acquisition step (S120),
In the hollow spiral carbon fiber mixing step (S100),
It is characterized by increasing the internal electrical conductivity of the negative electrode active material by adding a hollow spiral carbon fiber to increase the basic performance and charging efficiency of the lead acid battery.
By the method for producing a negative electrode active material for a lead acid battery using the hollow spiral carbon fiber,
It is characterized in that it can provide 57% life improvement with a lifespan of 374 cycles when the hollow spiral carbon fiber is added from 238 cycles, which is the lifespan without the addition of the hollow spiral carbon fiber.
A method for producing a negative electrode active material for a lead acid battery using a hollow spiral carbon fiber, characterized in that when the hollow spiral carbon fiber is added, the charging income is increased by 32% to 21.78 when the hollow spiral carbon fiber is added from 16.43, which is charged income without the addition of the hollow spiral carbon fiber. delete delete delete delete

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