KR20220023067A - Method for manufacturing a substrate for a lead acid battery with increased surface area - Google Patents

Abstract

The present invention relates to a method for manufacturing a substrate for a lead-acid battery with an increased surface area, and more specifically, to a method for manufacturing a substrate for a lead-acid battery with an increased surface area capable of increasing a bonding area between a grid and an active material and a thickness of a corrosion layer after formation by applying a sulfate-treated grid in the lead-acid battery to improve bonding strength between the grid and the active material; and improving durability by delaying easy separation of the active material depending on grid growth in a charging/discharging condition including overcharge through the improved bonding strength. The present invention improves the bonding strength between the grid and the active material by increasing the bonding area between the grid and the active material and the thickness of the corrosion layer after the formation. The present invention improves the durability by delaying the easy separation of the active material depending on the grid growth in the charging/discharging condition including the overcharge through the improved bonding strength. The method for manufacturing a substrate comprises: a touched area increasing step; and a bonding strength improving step.

Description

Method for manufacturing a substrate for a lead acid battery with increased surface area

The present invention relates to a method for manufacturing a substrate for a lead-acid battery having an increased surface area, and more particularly, by applying a grid treated with sulfuric acid in a lead-acid battery, the bonding area between the grid and the active material and the thickness of the corrosion layer after formation are increased to form a grid and A method for manufacturing a substrate for a lead-acid battery with increased surface area that improves the bonding strength of the active material and improves durability by delaying the easy separation of the active material according to grid growth under charge/discharge conditions including overcharge through improved bonding strength will be.

Basically, lead-acid battery separators are electronically insulators and ionically conductive.

That is, the separator comprised in the lead acid battery 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 small as possible pores to prevent electronic short circuit by dendrites or plate particles, and the internal cell resistance It is a porous insulator with as high a porosity as possible in order to minimize the

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

The separator should be stable throughout the life of the battery (refer to Korean Patent Application Laid-Open No. 10-2001-0042790).

As is well known, lead-acid batteries used in automobiles are secondary batteries that can be charged and discharged. They use diluted sulfuric acid (H2SO4) as an electrolyte and apply lead dioxide (PbO2) to the positive (+) electrode as an active material for the electrode. , When spongy lead (Pb) is applied to the negative (-) electrode and connected to an external circuit, electricity flows and discharge (the process of changing the composition of the active material of the initial positive and negative electrodes to lead sulfate (PbSO4)) and external It uses the principle of charging (the process of changing lead sulfate into an initial positive electrode active material and a negative electrode active material before discharging) when an electric current flows.

On the other hand, as the demand for mobile devices such as smartphones and electric vehicles is rapidly increasing, the demand for secondary batteries and lead-acid batteries as energy sources is gradually expanding.

In recent years, the demand for batteries has been expanding to various industrial fields such as the electronics industry, automobile industry, and energy storage industry. this is being requested

And, in a lead-acid battery, the electrode consists of an active material that stores electrical energy and a current collector (Grid) that moves electrical energy.

Current Collector and Grid are physically and chemically connected by a corrosion layer of ~2um called Corrosion Layer. This corrosion layer is easily separated from the grid as it grows as the grid corrodes in a high-temperature overcharged state.

This causes a sudden increase in water consumption and deterioration of battery performance, which leads to the end of battery life.

Therefore, there is a need for a manufacturing method to improve durability by delaying the grid-active material separation due to grid growth in a high-temperature charge/discharge cycle environment. This is to propose a method for manufacturing a substrate for lead-acid batteries with an increased surface area to increase the contact area of the material and increase the thickness of the corrosion layer and increase the contact area of the grid-active material.

Republic of Korea Patent Publication No. 10-2020-0040961

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

The purpose of the present invention is to improve the bonding force between the grid and the active material by increasing the bonding area between the grid and the active material and the thickness of the corrosion layer after formation by applying the sulfuric acid-treated grid in the lead-acid battery, and including overcharging through the improved bonding strength It is intended to improve the durability by delaying the easy separation of the active material according to the grid growth under the charging and discharging conditions.

In order to achieve the object to be solved by the present invention, a method for manufacturing a substrate for a lead-acid battery having an increased surface area according to an embodiment of the present invention,

After the strip punching process, sulfuric acid spray is primarily sprayed on the punched strip surface to sulfate a part of the thin oxidation protective layer 100 protecting the strip surface to form microcracks 200 on the strip surface. A contact area increasing step (S100) of increasing the contact area between the active material and the grid by increasing the grid surface area by forming it (S100); and

Secondary after formation, increasing the thickness of the corrosion layer (300, Corrosion Layer) between the grid and the active material to improve the bonding strength between the grid and the active material (S200) By including; to solve the problem of the present invention.

Through the method of manufacturing a substrate for a lead-acid battery with increased surface area, the present invention increases the bonding area between the grid and the active material and the thickness of the corrosion layer after formation by applying a grid treated with sulfuric acid in the lead-acid battery, thereby improving the bonding force between the grid and the active material In addition, through improved bonding strength, it provides the effect of improving durability by delaying the easy separation of the active material according to the grid growth under charge/discharge conditions including overcharge.

1 is a process diagram of a method for manufacturing a substrate for a lead-acid battery having an increased surface area according to an embodiment of the present invention.
2 is an exemplary view showing a sulfuric acid spray process of the method for manufacturing a substrate for a lead-acid battery having an increased surface area according to the present invention.

A method for manufacturing a substrate for a lead-acid battery having an increased surface area according to an embodiment of the present invention,

In the Punched Grid manufacturing process of lead-acid batteries,

After the strip punching process, sulfuric acid spray is primarily sprayed on the punched strip surface to sulfate a part of the thin oxidation protective layer 100 protecting the strip surface to form microcracks 200 on the strip surface. A contact area increasing step (S100) of increasing the contact area between the active material and the grid by increasing the grid surface area by forming it (S100); and

Secondary after formation, increasing the thickness of the corrosion layer (300, Corrosion Layer) between the grid and the active material to improve the bonding strength between the grid and the active material (S200) It is characterized in that it contains;

At this time, through the step of increasing the contact area ( S100 ) and the step of improving the bonding force ( S200 ), it is characterized in that the separation between the grid and the active material by grid growth is delayed.

At this time, by the method of manufacturing a substrate for a lead-acid battery having an increased surface area,

The life of the lead-acid battery to which the manufactured substrate is applied is characterized in that it can provide a 27% lifespan improvement from 1,920 cycles to 2,440 cycles.

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

By being able to provide a lead-acid battery containing a substrate for a lead-acid battery with an increased surface area, by applying a grid treated with sulfuric acid in the lead-acid battery, the bonding area between the grid and the active material and the thickness of the corrosion layer after formation are increased. It improves the bonding strength between the grid and the active material, and through the improved bonding strength, it delays the easy separation of the active material according to the grid growth under charge/discharge conditions including overcharge, thereby providing the effect of improving durability.

Hereinafter, it will be described in detail through an embodiment of the method for manufacturing a substrate for a lead-acid battery having an increased surface area according to the present invention.

1 is a process diagram of a method for manufacturing a substrate for a lead-acid battery having an increased surface area according to an embodiment of the present invention.

As shown in Figure 1, the present invention is a method for manufacturing a substrate for a lead-acid battery with increased surface area,

In the Punched Grid manufacturing process of lead-acid batteries,

After the strip punching process, sulfuric acid spray is primarily sprayed on the punched strip surface to sulfate a part of the thin oxidation protective layer 100 protecting the strip surface to form microcracks 200 on the strip surface. A contact area increasing step (S100) of increasing the contact area between the active material and the grid by increasing the grid surface area by forming it (S100); and

Secondary after formation, increasing the thickness of the corrosion layer (300, Corrosion Layer) between the grid and the active material to improve the bonding strength between the grid and the active material (S200) It is characterized in that it contains;

The present invention undergoes the manufacturing process as described above, and through this, by applying the grid with sulfuric acid treatment in the lead-acid battery, the bonding area between the grid and the active material and the thickness of the corrosion layer after formation are increased to improve the bonding force between the grid and the active material. possible effects will be provided.

Ultimately, it will provide the effect of improving the basic performance of the lead-acid battery and the charging efficiency.

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

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 a product mounted on a car, it is easily separated from the grid as the grid corrodes and grows in a high-temperature overcharged state.

This causes a sudden increase in water consumption and deterioration of battery performance, which leads to the end of battery life. Therefore, a technology for improving this is required.

In order to provide the above function, the step of increasing the contact area (S100) of the present invention is in the Punched Grid manufacturing process of the lead acid battery,

After the strip punching process, sulfuric acid spray is primarily sprayed on the punched strip surface to sulfate a part of the thin oxidation protective layer 100 protecting the strip surface to form microcracks 200 on the strip surface. It is a process of increasing the contact area between the active material and the grid by forming it to increase the grid surface area.

To explain with reference to FIG. 2, after the strip punching process of ① of FIG. 2, sulfuric acid spray is primarily sprayed on the punched strip surface to protect the metal surface as in ②. Sulfation increases the grid surface area by making fine cracks (200) on the strip surface as in ③ and ④.

Accordingly, since the grid surface area is increased, the contact area between the active material and the grid is increased.

After that, the bonding strength improvement step (S200) is secondarily formed after formation, and the thickness of the corrosion layer 300 between the grid and the active material is increased to increase the bonding strength between the grid and the active material. is a process to improve

That is, through the chemical conversion process, the thickness of the corrosion layer 300 between the grid and the active material is increased, which can improve the bonding force between the grid and the active material. there will be

Accordingly, through the step of increasing the contact area (S100) and the step of improving the bonding force (S200), it is characterized in that the separation between the grid and the active material by grid growth is delayed.

That is, by applying the sulfuric acid-treated grid in the lead-acid battery, the bonding area between the grid and the active material and the thickness of the corrosion layer after formation are increased to improve the bonding force between the grid and the active material, and the improved bonding strength can be achieved under the charging and discharging conditions including overcharging. As the grid grows, it delays the easy separation of the active material, thereby improving durability.

As described above, in order to grasp the effect of the present invention, an initial performance test and a life test were performed by making a product using a substrate for a lead acid battery manufactured using the method for manufacturing a substrate for a lead acid battery with an increased surface area of the present invention. The following results were obtained.

The conventional product shown in the table below is a product (BX80) made using a substrate produced by applying the prior art made by the company that is the applicant of the present invention, and Examples 1 and 2 are produced using the manufacturing method of the present invention. This is the experimental result of the product made using the used substrate.

Even for products of the same standard, for example, since the density of the separator cannot be the same for each product, each product cannot produce the same action and effect. Each Example 1 and Example 2 were defined and tested as follows, and the results were prepared in Tables 1 and 2 below.

division requirements Conventional product Example 1 Example 2 RC 130 minutes 133 minutes 137 minutes 135 minutes 102% 105.6% 103.8% CCA 7.2V
630A 7.23V 7.95V 7.6V 633A 689A 680A 100.9% 109.2% 108.2% C20 75AH 75.52AH 77.9AH 76.21AH 100.7% 103.8% 101.6%

1) Reserved Capacity (RC: Reserve Capacity)

Retention capacity RC measures the possible discharge time until the discharge end voltage of 105V is reached with a discharge current of 25A at 25°C after being left for at least 1 hour after the completion of a full charge. It is a measure of how long a minimum function can be exerted to operate a load, etc.

As a result of the test, as shown in Table 1, when the electrode plate was manufactured using the substrate according to the present invention, the holding capacity (RC) was 135 to 137 minutes, which in general can provide a better holding capacity than the conventional substrate. there was.

2) Cold Cranking Ampere (CCA)

In general, the rapid discharge characteristic of a storage battery deteriorates rapidly at -10°C or less. The low-temperature starting current (CCA) is a high-rate discharge test to evaluate the vehicle starting ability at low temperature. Measure the voltage during discharge.

In this test, a voltage of 7.2V or more is required for 30 seconds, and the higher the voltage, the better the performance.

In the present invention, the CCA was calculated using a correction equation of (30 sec voltage/6 - 0.2)×630.

As a result of the test, as shown in Table 1, the voltage for 30 seconds was 7.23V and converted CCA was 633A for the conventional substrate, but when the substrate of the present invention was used, the voltage for 30 seconds was 7.6V or more and the converted CCA was 680A or more, about 7% It showed an effect of ~8%.

3) 20 hour rate capacity (AH)

This is to investigate the low-rate discharge characteristics, and the discharge capacity (AH) is measured until the voltage reaches 10.5V by continuously discharging at 3.75A, which is a relatively small current for the storage battery capacity.

As a result of the test, 76.21AH ~ 77.9AH showed almost the same test result as the product using the existing substrate, but the capacity was increased by 1-3% compared to the existing substrate.

4) Life test

In the life test, after discharging at 25A for 4 minutes in a fully charged state, the process of charging at 14.8V maximum 25A for 10 minutes is repeated 480 times a week, and then, after 56 hours of standing, high-rate discharge at 630A to measure the voltage for 30 seconds to determine the lifespan.

In this test, if the voltage for 30 seconds is more than 7.2V, repeat 1 week again, and if it is less than 7.2V, it is judged as the end of life.

As a result of the life test, as shown in Table 2, the lifespan of the substrate of the present invention was terminated at 2,440 (Cycles) charge/discharge, showing a 27% lifespan extension effect compared to the existing substrate.

Total number of discharges 30 second voltage [V] note Conventional product 1 Example 1 Example 2 480 9.21 9.35 9.30 960 8.81 9.05 9.03 1440 8.19 8.53 8.75 1920 7.68 8.25 8.17 2440 6.88 7.58 7.33 2920 5.15 5.08 Lifespan determination 1920 2440 2440 27% increase

In the end, through the above test, it is possible to provide an increase in the contact area between the grid and the active material and an increase in the thickness of the corrosion layer due to the corroded grid surface, resulting in grid-active material separation due to grid growth in a high-temperature charge/discharge cycle environment. It is possible to improve durability by delaying the

In other words, it was found that by increasing the contact area between the grid and the active material, the effect of improving the starting ability of the lead-acid battery due to the increased reaction area and the effect of improving the product's performance and extending the lifespan could be obtained.

Through the manufacturing method as described above, by applying the sulfuric acid-treated grid in the lead-acid battery, the bonding area between the grid and the active material and the thickness of the corrosion layer after formation are increased to improve the bonding force between the grid and the active material, and through the improved bonding strength, It provides the effect of improving durability by delaying the easy separation of the active material according to grid growth under charge-discharge conditions including charging.

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 characteristics of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all aspects and not restrictive.

S100: contact area increase step
S200: bonding strength improvement step

Claims (4)

In the method for manufacturing a substrate for a lead-acid battery having an increased surface area,
In the Punched Grid manufacturing process of lead-acid batteries,
After the strip punching process, sulfuric acid spray is primarily sprayed on the punched strip surface to sulphate a part of the thin oxidation protective layer 100 protecting the strip surface to form microcracks 200 on the strip surface. A contact area increasing step (S100) of increasing the contact area between the active material and the grid by forming the grid surface area (S100); and
Secondary after formation, the bonding strength improvement step (S200) of increasing the thickness of the corrosion layer (300, Corrosion Layer) between the grid and the active material to improve the bonding strength between the grid and the active material (S200) A method of manufacturing a substrate for a lead-acid battery having an increased surface area, comprising:
The method of claim 1,
Through the step of increasing the contact area (S100) and the step of improving the bonding strength (S200), a method for manufacturing a substrate for a lead-acid battery with an increased surface area, characterized in that the separation between the grid and the active material by grid growth is delayed.
The method of claim 1,
By a method for manufacturing a substrate for a lead-acid battery having an increased surface area,
A method for manufacturing a substrate for a lead-acid battery with an increased surface area, characterized in that the lifespan of the lead-acid battery to which the manufactured substrate is applied can provide a 27% lifespan improvement from 1,920 cycles to 2,440 cycles.
By the manufacturing method of claim 1,
A lead-acid battery comprising a substrate for a lead-acid battery with an increased surface area.

Images