Method of manufacturing positive plate of lead acid battery with PVDF band

Abstract

The present invention relates to a method for manufacturing a positive plate of a lead-acid battery containing a PVDF band, and more specifically, to a method for manufacturing a positive plate of a lead-acid battery containing a PVDF band that prevents the positive plate from growing excessively through the excellent mechanical strength and structural characteristics of PVDF, and facilitates electron transfer through the pores of PVDF, thereby improving the performance and durability of the lead-acid battery. According to the present invention, by forming a PVDF band, the growth of the anode plate can be effectively suppressed. In addition, by using PVDF bands, lead-acid batteries can maintain their performance even in high-temperature environments.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a positive plate of a lead-acid battery containing a PVDF band, and more specifically, to a method for manufacturing a positive plate of a lead-acid battery containing a PVDF band that prevents the positive plate from growing excessively through the excellent mechanical strength and structural characteristics of PVDF, and facilitates electron transfer through the pores of PVDF, thereby improving the performance and durability of the lead-acid battery. Background Technology

[0002] Basically, battery separators are electronically insulators and ionically conductors.

[0003] That is, the separator prevents direct electronic contact between electrodes of opposite polarity while enabling ionic current between the electrodes. To satisfy these two functions, the separator is generally a porous insulator having pores as small as possible to prevent electronic short circuits caused by dendrites or plate particles, and having a porosity as high as possible to minimize internal cell resistance.

[0004] In a lead-acid battery, the separator also determines the appropriate electrode spacing and thereby defines the amount of electrolyte participating in the cell reaction.

[0005] The separator must remain stable throughout the battery's lifespan. (Refer to Korean Patent Publication No. 특2001-0042790)

[0006] As is well known, lead-acid batteries used in automobiles and the like are rechargeable secondary batteries that utilize the principle that dilute sulfuric acid (H2SO4) is used as the electrolyte, lead dioxide (PbO2) is coated on the positive (+) electrode and spongy lead (Pb) is coated on the negative (-) electrode as the active material of the electrodes, and when connected to an external circuit, electricity flows to discharge (a process in which the initial active material composition of the positive and negative electrodes changes into lead sulfate (PbSO4)), and when current is applied from the outside, charging (a process in which lead sulfate changes into the initial positive and negative active materials before discharge).

[0007] The positive plate (1) and negative plate (2) coated with active material come in various forms depending on the manufacturing method, and provide a structure of a paste-type electrode.

[0008] This consists of a grid-shaped substrate (5) and a paste-like active material applied thereon.

[0009] Typically, the substrate (5) is made of an alloy composed mainly of antimony (Sb) and calcium (Ca) to enhance mechanical strength and corrosion resistance, and the manufacturing method involves casting by gravity pouring into a mold or casting by continuous rolling. (Refer to Korean Patent Publication No. 2000-0031876)

[0010] The active material is a component that plays an important role in the performance of a lead-acid battery and is manufactured by continuously applying fine powdered lead oxide (PbO) and a paste-like mixture onto a substrate using a coating machine, followed by aging, drying, and an electrical oxidation and reduction process.

[0011] Lead dioxide (PbO2), which is the positive active material, consists of countless fine particles of oxidized lead bonded together and is rich in porosity, allowing the electrolyte to freely diffuse and penetrate between the particles.

[0012] In addition, the spongy lead, which is the active material of the cathode plate, is also rich in porosity and reactivity, allowing the electrolyte to penetrate freely.

[0013] The positive and negative plates manufactured as described above are separated by a porous non-conductive separator (3) to prevent direct contact (short) between the two plates, and are then placed in a product container (a container constituting the product) for assembly.

[0014] The lead-acid battery produced in this way exerts electrical performance through its internal electrolyte, and charging and discharging take place inside the vehicle.

[0015] The lifespan of lead-acid batteries installed in vehicles is affected by the vehicle's operating conditions (average daily mileage, driver's driving habits, road conditions) and the electrical load status of the vehicle's electrical components.

[0016] However, harsh operating conditions and excessive electrical loads reduce the bonding strength of the porous positive plate active material (PbO2), and the detachment of this active material reduces the reactivity of the positive and negative plates, leading to a degradation in electrical performance and ultimately becoming a factor that shortens the lifespan of the lead-acid battery.

[0017] As described above, in order to reduce the shedding of active material from the electrode plate, a method is used to manufacture the electrode plate in which an electrochemically active active material is applied to a cast or expanded substrate and a nonwoven fabric made of a thermoplastic resin is pressed to a certain depth on the surface of the active material. In a lead-acid battery composed of multiple electrode plates with an active material layer attached to the surface, a thin fiber mesh is placed over the outer surface of the active material layer, and a known separator formed of a polyethylene-based polymer material with protrusions formed on the inner surface is installed on the outer surface of the fiber mesh to reduce the shedding of active material, suppress the growth of dendrites, and reduce the thickness of the separator, thereby reducing the size of the lead-acid battery.

[0018] The use of the aforementioned nonwoven fabric and fiber mesh is widely applied in batteries according to their respective characteristics. In nickel-zinc secondary batteries, to regulate the optimal amount of electrolyte in balance between battery life and discharge performance of a separator (separator plate) composed of a microporous film and a nonwoven fabric, the utilization rate of the zinc anode is increased to extend the battery life. This is achieved by wrapping a Ni anode wrapped in a polypropylene nonwoven fabric and a Zn anode wrapped in cotton nonwoven fabric and polypropylene nonwoven fabric with a polypropylene microporous film to adjust the ratio of the amount of electrolyte absorbed into the separator to the total amount of electrolyte within the battery. In an alkali zinc accumulator, a polypropylene nonwoven fabric is formed to separate the Ni anode and the Zn anode, and a multilayer separator having multiple layers of microporous membranes is disposed on the outside of the Ni anode, Zn anode, and polypropylene nonwoven fabric. In this alkali zinc accumulator, between the Zn anode of the multilayer separator and the polypropylene nonwoven fabric Polyolefin-based nonwoven fabrics and membranes composed of polymers in batteries, such as separators made from a blend of polyolefin copolymers and polyolefin polymer oligomers, are widely used in the manufacture of separators for alkali zinc batteries and lithium-ion batteries characterized by having a cotton nonwoven fabric.

[0019] Most separators currently used in lead-acid batteries are rechargeable porous polyethylene separators, and their primary purpose is to prevent short circuits by preventing direct contact between the positive and negative plates, and their secondary purpose is to enable ion current flow with low resistance between the positive and negative plates.

[0020] Meanwhile, when the positive plate of a lead-acid battery is used at high temperatures, chemical reactions become more active, which causes the active material on the positive plate to swell or grow.

[0021] At this time, due to repeated charge-discharge cycles at high temperatures and chemical reactions of the electrolyte, the structure of the anode plate is deformed, and as material accumulates, the volume of the anode plate increases.

[0022] In addition, the grown positive plate is more likely to come into contact with the negative strap inside the lead-acid battery, and this contact becomes a major cause of short circuits.

[0023] If the aforementioned short circuit occurs, a direct electrical short circuit takes place inside the battery, generating excessive heat. This leads to a decrease in battery performance and a shortened lifespan, and in severe cases, there is a risk of the battery completely failing or exploding.

[0024] Furthermore, the growth of the positive plate increases the internal resistance of the battery, which leads to a decrease in electrical efficiency, and also causes the battery's durability to gradually weaken during repeated charging and discharging processes.

[0025] Therefore, there is a need for technology that enhances the safety of lead-acid batteries by preventing short circuits, technology that maintains battery performance and capacity and extends battery life by suppressing the growth of positive plates, and technology that ensures structural stability to enable continuous performance even in high-temperature environments. Prior art literature

[0026] Republic of Korea Published Patent Application No. 10-2001-0042790 Republic of Korea Published Patent No. 10-2000-0031876 The problem to be solved

[0027] Therefore, the present invention has been devised to resolve the aforementioned conventional problems,

[0028] The objective of the present invention is to form PVDF bands on the anode plate to prevent excessive growth of the anode plate through the excellent mechanical strength and structural properties of PVDF, and to facilitate electron transfer through the pores of PVDF. means of solving the problem

[0029] In order to achieve the problem to be solved by the present invention, a method for manufacturing a positive plate of a lead-acid battery containing a PVDF band according to one embodiment of the present invention is,

[0030] A positive plate preparation step (S100) for preparing a positive plate during the electrode plate group assembly process; and

[0031] A PVDF band attachment step (S200) for forming a PVDF band of a certain size on the prepared anode plate (50); and

[0032] By including a positive plate completion step (S300) for manufacturing a positive plate by introducing it into a dryer and drying it at a high temperature, the problem of improving the durability of a lead-acid battery is solved. Effects of the invention

[0033] The method for manufacturing a positive plate of a lead-acid battery containing a PVDF band according to the present invention significantly improves the durability and stability of the lead-acid battery, and the following are the main effects of the present invention.

[0034] First, by forming a PVDF band, the growth of the anode plate can be effectively inhibited.

[0035] This prevents the positive plate from growing excessively in a high-temperature environment and coming into contact with the negative strap, thereby preventing the occurrence of short circuits and extending the lifespan of the lead-acid battery.

[0036] Second, by using PVDF bands, the lead-acid battery can maintain its performance even in high-temperature environments.

[0037] In other words, the stability and reliability of lead-acid batteries are improved in high-temperature environments, and high-temperature durability is increased.

[0038] According to the experimental results, lead-acid batteries using PVDF bands showed a 25% or greater improvement in high-temperature durability.

[0039] Third, the PVDF band has a porous structure, which increases the contact area with the electrolyte and promotes electron transfer.

[0040] In other words, the charging and discharging efficiency of the battery is improved, and overall electrical performance is enhanced.

[0041] Fourth, the use of PVDF bands inhibits the growth of the anode plate and promotes electron transfer, allowing the initial performance of the battery to be maintained for a long period.

[0042] As a result, the capacity retention rate of the lead-acid battery is increased, enabling stable performance even during long-term use.

[0043] Fifth, it increases the physical and chemical stability of the anode plate, maintaining high durability even during repeated charge-discharge cycles.

[0044] As a result, the overall lifespan of the lead-acid battery is extended, and maintenance and replacement costs are reduced.

[0045] Sixth, inhibiting positive plate growth reduces the possibility of short circuits and prevents excessive heat generation that may occur inside the battery.

[0046] As a result, the safety of lead-acid batteries is significantly improved, making it possible to reduce risks such as explosions or fires. Brief explanation of the drawing

[0047] FIG. 1 is a process diagram of a method for manufacturing a positive plate of a lead-acid battery containing a PVDF band according to an embodiment of the present invention. FIG. 2 is a conceptual example diagram showing the position and size of a PVDF band when the size of the positive plate is set to 150 mm in width and 200 mm in height in a method for manufacturing a positive plate of a lead-acid battery containing a PVDF band according to an embodiment of the present invention. FIG. 3 is a graph comparing the durability (SAE J2801) of a battery containing a positive plate of a lead-acid battery containing a PVDF band manufactured in a method for manufacturing a positive plate of a lead-acid battery containing a PVDF band according to an embodiment of the present invention and a conventional product. Specific details for implementing the invention

[0048] Hereinafter, the present invention may be subject to various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail.

[0049] However, this is not intended to limit the invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0050] These embodiments are provided to further explain the invention in detail to those skilled in the art to which the invention pertains.

[0051] Accordingly, the shape of each element shown in the drawings may be exaggerated to emphasize a clearer explanation, and in describing the present invention, if it is determined that a detailed description of related known technology may obscure the essence of the present invention, such detailed description is omitted.

[0052] Terms such as first, second, etc. may be used to describe various components, but components should not be limited by the terms.

[0053] Terms are used solely for the purpose of distinguishing one component from another.

[0054] The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention.

[0055] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0056] In the present invention, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0057] A method for manufacturing a positive plate of a lead-acid battery containing a PVDF band according to one embodiment of the present invention is,

[0058] A positive plate preparation step (S100) for preparing a positive plate during the electrode plate group assembly process; and

[0059] A PVDF band attachment step (S200) for forming a PVDF band of a certain size on the prepared anode plate (50); and

[0060] It is characterized by including an anode plate completion step (S300) for manufacturing an anode plate by introducing it into a dryer and drying it at a high temperature.

[0061] At this time, the above PVDF (Polyvinylidene fluoride) band is characterized by being manufactured into a porous gamma type by a copolymerizing method.

[0062] At this time, by forming the above PVDF (Polyvinylidene fluoride) band at a certain location on the positive plate with a certain size, the growth of the positive plate is suppressed and the high-temperature durability of the lead-acid battery can be improved.

[0063] At this time, the positive plate of a lead-acid battery containing a PVDF band, manufactured by the above manufacturing method, is applied to a lead-acid battery.

[0064] Hereinafter, the method for manufacturing a positive plate of a lead-acid battery containing a PVDF band according to the present invention will be explained in detail through an example.

[0065] FIG. 1 is a process diagram of a method for manufacturing a positive plate of a lead-acid battery containing a PVDF band according to an embodiment of the present invention.

[0066] As illustrated in FIG. 1, the method for manufacturing a positive plate of a lead-acid battery containing a PVDF band according to the present invention is,

[0067] A positive plate preparation step (S100) for preparing a positive plate during the electrode plate group assembly process; and

[0068] A PVDF band attachment step (S200) for forming a PVDF band of a certain size on the prepared anode plate (50); and

[0069] It is characterized by including an anode plate completion step (S300) for manufacturing an anode plate by introducing it into a dryer and drying it at a high temperature.

[0070] At this time, the above PVDF (Polyvinylidene fluoride) band is characterized by being manufactured into a porous gamma type by a copolymerizing method.

[0071] At this time, by forming the above PVDF (Polyvinylidene fluoride) band at a certain location on the positive plate with a certain size, the growth of the positive plate is suppressed and the high-temperature durability of the lead-acid battery can be improved.

[0072] Next, I will explain the manufacturing stage in detail.

[0073] The positive plate preparation step (S100) of the present invention is a step of preparing a positive plate during the electrode group assembly process, and subsequently, an active material is applied to the electrode plate.

[0074] Afterwards, a PVDF band attachment step (S200) is performed to form a PVDF band (100) of a certain size on the prepared anode plate (50).

[0075] To explain in detail, as a PVDF band preparation step, the above PVDF (Polyvinylidene fluoride) band is prepared into a porous gamma type by a copolymerizing method.

[0076] In addition, it is characterized by setting the fluorine content to between 20% and 50%, and the single molecular weight to between 20,000 and 200,000.

[0077] In addition, the band size is characterized by being able to be manufactured in various sizes depending on the type of electrode plate.

[0078] Afterwards, as a PVDF band application step, the prepared PVDF band is evenly applied to the surface of the positive electrode plate, and application methods include coating, wrapping, and laminating.

[0079] When applying the above, care must be taken to ensure that the PVDF band adheres uniformly to the electrode plate, and to this end, the adhesion strength is increased by using a roller or compression equipment.

[0080] Afterwards, the anode plate is introduced into a dryer and dried at a high temperature to undergo the anode plate completion step (S300) for manufacturing the anode plate.

[0081] Specifically, as a high-temperature treatment step, the anode plate with the attached PVDF band is treated at a high temperature to ensure that the PVDF adheres well to the plate.

[0082] The above high temperature treatment temperature is set between 100°C and 150°C depending on the characteristics of PVDF, and the treatment time is adjusted between 10 minutes and 30 minutes.

[0083] Subsequently, in the cooling and inspection stage, the anode plate is gradually cooled after high-temperature treatment to ensure stable attachment of the PVDF bands, and the cooled anode plate is inspected to verify whether the PVDF bands are uniformly attached and whether there are any bubbles or defects.

[0084] Meanwhile, the reason for preparing the above PVDF (Polyvinylidene fluoride) into a porous gamma type by copolymerizing, setting the fluorine content to between 20% and 50%, and setting the single molecular weight to between 20,000 and 200,000 is that it provides various technical and performance advantages as follows.

[0085] First, in the case of porous gamma-type PVDF, the porous structure significantly increases the contact area with the electrolyte, facilitating electron movement and improving the performance of the battery. It also has the advantage of providing a high surface area, allowing chemical reactions to occur more actively, and the porous structure can reduce weight, thereby contributing to the lightweighting of the entire lead-acid battery.

[0086] Second, in the case of the copolymerization method, the physical properties of PVDF can be finely controlled through copolymerization, thereby enabling the securing of desired mechanical strength, flexibility, and chemical resistance.

[0087] In addition, by improving crystallinity and thermoplasticity, it is possible to obtain PVDF with excellent processability and heat resistance.

[0088] Third, in the case of a fluorine content of 20% to 50%, the chemical resistance of PVDF improves as the fluorine content increases, thereby increasing resistance to chemical reactions inside the lead-acid battery, and the aforementioned fluorine content increases the mechanical strength of PVDF, enabling it to operate stably even in high-temperature environments.

[0089] In addition, the above fluorine content affects electrical insulation and dielectric constant, thereby enabling the optimization of the electrical performance of the lead-acid battery.

[0090] Fourth, when the single molecular weight is set between 20,000 and 200,000, the viscosity of PVDF increases, improving processability, which allows it to be easily processed into various forms.

[0091] For example, as in the present invention, it can be configured to be installed at a certain location with a certain size in the form of a band.

[0092] In addition, by setting the single molecular weight as described above, mechanical strength and tensile strength are improved, and thermal stability is enhanced, enabling the maintenance of excellent performance even in high-temperature environments.

[0093] In conclusion, when a PVDF band manufactured under the above conditions is used in the positive electrode plate of a lead-acid battery, it suppresses grid growth and promotes electron movement, thereby significantly improving the performance and durability of the battery.

[0094] In addition, by enhancing high-temperature durability, the lifespan of the lead-acid battery can be extended even in high-temperature environments.

[0095] Furthermore, the size of the PVDF band can be designed in various ways depending on the size and shape of the anode plate. I will explain how the size of the PVDF band can be set, using the size of a typical lead-acid battery anode plate as an example.

[0096] As shown in FIG. 2, when the size of the anode plate is set to 150 mm in width and 200 mm in height, the width of the PVDF band does not cover the entire width of the anode plate but is attached partially, for example, by setting the width of the PVDF band to 30 mm and the length to cover the entire length of the anode plate, for example, by setting it to 200 mm.

[0097] In addition, the thickness can be set between 0.1mm and 1mm.

[0098] In addition, the PVDF band is attached vertically to one edge of the anode plate. This positioning is intended to suppress grid growth of the anode plate and improve electron mobility, and the band is attached to the anode plate by high-temperature compression.

[0099] At this time, the high-temperature treatment temperature is set between 100°C and 150°C, and the attachment time is controlled between 10 minutes and 30 minutes, thereby allowing the PVDF band to be firmly adhered to the anode plate.

[0100] In conclusion, the porous structure of the PVDF band facilitates electron movement, thereby improving battery performance; the PVDF band inhibits grid growth on the anode plate, extending the lifespan of the lead-acid battery; and the excellent thermal properties of the PVDF band enable the anode plate to maintain performance even in high-temperature environments.

[0101] As described above, in order to determine the effects of the present invention, tests were conducted on a lead-acid battery using a conventional electrode plate and a lead-acid battery using an electrode plate including the PVDF band of the present invention, and a product having a final capacity of 80Ah was produced through subsequent processes such as assembly and formation.

[0102] The term "conventional product" described below refers to a lead-acid battery using a general electrode plate manufactured by the applicant, and the term "improved product" refers to a lead-acid battery using an electrode plate including a PVDF band.

[0103] Below, I will explain the durability (SAE J2801) graph in detail.

[0104] division Conventional product improved product SAE J2801 8 Unit 10 Unit

[0105] Table 1 and Figure 3 above are based on a test with a 70AH capacity lead-acid battery, and the test results confirmed that high-temperature durability increased by adding a PVDF band to the improved product compared to the conventional product.

[0106] Specifically, regarding the initial voltage (0 Unit), both the conventional product and the improved product start with an initial voltage of about 12V, which means that the two batteries show similar performance in the initial state.

[0107] Subsequently, for the intermediate units (1 to 7 units), as the number of test units increases, the voltage of both the conventional product and the improved product gradually decreases, but the conventional product tends to drop slightly faster.

[0108] In the case of conventional products, the voltage drops sharply at 8 Units and decreases to about 7.5V, so that it can no longer provide usable voltage.

[0109] This indicates that conventional lead-acid batteries have reached their durability limit at this point.

[0110] On the other hand, in the case of the improved product (8 to 10 Units), the lead-acid battery using the PVDF band maintains a relatively high voltage even after 8 Units, and decreases to about 10.5V at 9 Units and about 9V at 10 Units.

[0111] This indicates that the improved lead-acid battery can maintain high performance for a longer period than conventional lead-acid batteries.

[0112] As a result, it was found that the lead-acid battery using the PVDF band maintained a significant voltage up to 10 units according to SAE J2801 standards, and that its durability was improved compared to the conventional lead-acid battery (8 units).

[0113] In addition, by adding PVDF bands, electron movement is facilitated and grid growth on the anode plate is suppressed, thereby enabling performance that allows it to withstand high-temperature environments for a longer period.

[0114] And, below, I will explain the charging acceptance test in detail.

[0115] The above Charge Acceptance Test (CA) involves discharging a fully charged sample at room temperature (25±2℃) for 2.5 hours at a 5-hour rate current (17.5A based on 70Ah), and then leaving it at a temperature of 0±2℃ for at least 12 hours.

[0116] Afterwards, charge at a constant voltage of 14.4V±0.1V and measure the current after 10 minutes of charging.

[0117] As a result of the test, it was found that the current of the improved product increased by about 53% in about 10 minutes compared to the conventional product due to its high electrical conductivity and charging efficiency.

[0118] division hour Conventional product improved product Charging income 1 minute 27.25 29.99 2 minutes 24.21 29.62 3 minutes 22.14 28.92 4 minutes 21.25 28.12 5 minutes 20.11 27.71 6 minutes 19.35 27.12 7 minutes 18.74 26.76 8 minutes 17.68 26.17 9 minutes 17.04 25.96 10 minutes 16.43 25.16

[0119] Through the manufacturing method described above, the performance, durability, and stability of the lead-acid battery are significantly improved, and the following are the main effects of the present invention.

[0120] First, by forming a PVDF band, the growth of the anode plate can be effectively inhibited.

[0121] Second, by using PVDF bands, the lead-acid battery can maintain its performance even in high-temperature environments.

[0122] According to the experimental results, lead-acid batteries using PVDF bands showed a 25% or greater improvement in high-temperature durability.

[0123] Third, the PVDF band has a porous structure, which increases the contact area with the electrolyte and promotes electron transfer.

[0124] Those skilled in the art to which the present invention pertains will understand that the present invention, as described above, may be implemented in other specific forms without altering the technical concept or essential features of the invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0125] 50 : Positive plate 100 : PVDF band

Claims

Claim 1 A method for manufacturing a positive plate of a lead-acid battery containing a PVDF band, comprising: a positive plate preparation step (S100) for preparing a positive plate during a process of assembling a group of electrode plates; a PVDF band attachment step (S200) for forming a PVDF band of a certain size on the prepared positive plate (50); and a positive plate completion step (S300) for manufacturing a positive plate by introducing it into a dryer and drying it, wherein the PVDF (Polyvinylidene fluoride) band is manufactured into a porous gamma type by a copolymerizing method. Claim 2 delete Claim 3 A method for manufacturing a positive plate of a lead-acid battery containing a PVDF band, characterized in that, in claim 1, by forming a PVDF (Polyvinylidene fluoride) band of a certain size at a certain location on the positive plate, the growth of the positive plate is suppressed and the high-temperature durability of the lead-acid battery is improved. Claim 4 A positive plate of a lead-acid battery containing a PVDF band, manufactured by the manufacturing method of claim 1.

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