How to improve the electrical conductivity using a fullerene

Abstract

The present invention relates to a method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene. More specifically, the invention relates to a method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene, wherein fullerene is added to the active material added to the negative electrode of a conventional lead-acid battery instead of a polyester-based fiber which is an electrode plate active material binder, thereby improving ion mobility and enhancing the basic performance and charging efficiency of the lead-acid battery.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene. More specifically, the invention relates to a method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene, wherein fullerene is added to the active material added to the negative electrode of a conventional lead-acid battery instead of a polyester-based fiber which is an electrode plate active material binder, thereby improving ion mobility and enhancing the basic performance and charging efficiency of the lead-acid battery. Background Technology

[0002] Currently, the active material mechanism of lead-acid batteries involves adding polyester-based fibers to the active material to secure physical strength and a surface area for reaction with sulfuric acid.

[0003] Typically, polyester fibers with a fineness of 2 to 5 denier and a length of 1 to 10 mm are added to the active material of a lead-acid battery, and these fibers have excellent acid resistance and oxidation resistance.

[0004] At this time, the added organic synthetic staple fibers typically have a circular cross-sectional shape and a length of about 2 to 10 mm.

[0005] The main components of organic synthetic staple fibers consist of polypropylene, polyester, and modacrylic series, which have excellent acid and oxidation resistance.

[0006] The prior art, Korean Patent Registration No. 10-0603908, "Electrode plate for a battery and method for manufacturing the same," discloses a method for manufacturing an electrode plate in which fiber-reinforced paper is attached to the surface of an active material by applying pressure so that fiber filaments are embedded therein, and the active material is filled into the uneven surface portions.

[0007] The aforementioned prior Korean registered patent relates to "electrode plates for batteries and methods for manufacturing the same," wherein an active material having electrochemical activity is coated onto a substrate that serves as a pathway for electricity flow, and fiber-reinforced paper is attached to the surface of the active material by applying pressure so that the fiber filaments of the fiber-reinforced paper are embedded to a certain depth during the step of attaching or pressing the fiber-reinforced paper. By filling the uneven surface areas of the fiber-reinforced paper with the active material and increasing the bonding surface area, the technology prevents the active material from detaching from the substrate. Furthermore, it relates to a technology that improves the initial high-rate discharge characteristics of the electrode plate due to the porosity of the fiber-reinforced paper and extends the lifespan of the battery by effectively retaining and supporting the active material through the stable support force and acid resistance of the fiber filament structure of the fiber-reinforced paper.

[0008] Until now, lead (Pb)-calcium (Ca)-tin (Sn) alloys have been used as grid alloys for lead-acid batteries, but it has been pointed out that this alloy composition alone is insufficient to cope with harsh operating environments (high temperature and overcharging phenomena), and that corrosion of the grid or deformation caused by corrosion growth is occurring, which shortens the lifespan of the lead-acid battery.

[0009] Accordingly, improvements in the corrosion resistance and mechanical strength of the grid, as well as the suppression of growth deformation, are required.

[0010] Meanwhile, the active material of conventional lead-acid batteries is generally based on lead powder and an aqueous sulfuric acid solution, and the active material is produced by combining other additives according to the characteristics of the positive and negative electrodes.

[0011] The active material produced in this way undergoes a coating process, which involves applying it to a substrate. After undergoing aging and drying processes according to the positive and negative electrode characteristics, multiple prepared positive and negative plates are stacked alternately. At this time, a non-conductive separator is installed to prevent electrical short circuits between the plates, so that the positive, negative, and separator plates form a plate group.

[0012] Multiple electrode plates are connected in series and housed within the battery according to their capacity.

[0013] The above-mentioned group of electrode plates undergoes a supercharged formation process to acquire electrical properties. At this time, the active material of the positive plate is formed as lead dioxide (PbO2), and due to its characteristics, it has countless fine particles of oxidized lead bonded together and is rich in porosity, allowing the electrolyte to freely diffuse and penetrate between the particles.

[0014] In addition, the active material of the cathode plate is spongy lead (Pb), which is also rich in porosity and reactivity, allowing the electrolyte to freely diffuse and penetrate.

[0015] Only then can the product created in this way be used in the market.

[0016] In addition, to facilitate the initial filling process and improve product durability, separate aging and drying processes are performed according to polarity.

[0017] The aging process of the anode plate is an important process that increases the durability of the product. It not only changes the lead (Pb), a component of the active material, into lead oxide (PbO) using the hot temperature (about 70 to 100°C) and moisture (humidity 99% or higher), but also changes the crystal structure of the active material.

[0018] If the cathode plate is left in a natural state without a separate process, aging and drying can be performed simultaneously.

[0019] However, if sufficient aging and drying are not performed, the electrodes stick together during the assembly process of forming the electrode group, and the presence of moisture reduces the durability of the active material, causing the active material embedded between the substrates to easily detach even with a minor impact.

[0020] In lead-acid batteries produced through such a process, as the number of charge and discharge cycles increases, the active material detaches more easily from the substrate due to the reaction between lead and sulfuric acid. Since the detached active material can no longer participate in the reaction, it ultimately degrades the performance of the lead-acid battery, making its lifespan typically only 1 to 2 years.

[0021] Therefore, in line with the current trend demanding high-performance lead-acid batteries, there is a need for manufacturing processes that can improve the durability and performance of lead-acid batteries.

[0022] As a prior art, the invention “negative electrode active material and method of manufacturing the same and lead-acid battery” has disclosed a technology relating to a negative electrode active material characterized by the addition of lignin to lead powder.

[0023] However, it was difficult to expect the above technology to have the effect of improving the lifespan of the active material. Prior art literature

[0024] Republic of Korea Patent Registration No. 10-0483246 The problem to be solved

[0025] Therefore, the present invention has been devised to resolve the aforementioned conventional problems,

[0026] The objective of the present invention is to provide a method for manufacturing an electrode plate for a lead-acid battery with improved electrical conductivity using fullerene, which can improve the basic performance and charging efficiency of the lead-acid battery by improving ion mobility through the addition of fullerene to the active material added to the negative electrode of a conventional lead-acid battery, instead of polyester-based fibers which are electrode plate active material binders.

[0027] Another objective of the present invention is to improve the efficiency of lead-acid batteries during the manufacturing process. means of solving the problem

[0028] In order to achieve the problem to be solved by the present invention, a method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene according to one embodiment of the present invention is,

[0029] In the process of mixing the negative electrode active material of a lead-acid battery,

[0030] A fullerene mixing step (S100) for distributing fullerene within the cathode active material by adding and mixing fullerene instead of polyester fibers when compounding lead powder, sulfuric acid, and additives according to the cathode; and

[0031] The problem of the present invention is solved by including a natural aging and drying step (S200) for applying a cathode active material containing fullerene to a lead substrate and then naturally aging and drying it in the atmosphere. Effects of the invention

[0032] Through the method for manufacturing a lead-acid battery electrode plate that improves electrical conductivity using fullerene according to the present invention, by adding fullerene instead of polyester-based fibers, which are electrode plate active material binders, to the active material added to the negative electrode of a conventional lead-acid battery, the ion mobility is improved, thereby providing the effect of improving the basic performance and charging efficiency of the lead-acid battery.

[0033] In other words, by adding fullerene to the active material of a lead-acid battery to improve electrical conductivity within the battery, the electrical loss caused by resistance during charging and discharging is reduced, thereby providing the effect of improving the initial performance and durability of the lead-acid battery.

[0034] Furthermore, in a lead-acid battery manufactured by adding fullerene to the negative electrode active material, not only can the basic performance of the lead-acid battery be enhanced due to the high conductivity characteristics of fullerene, but there is also an effect of improving the efficiency of lead-acid battery production. Brief explanation of the drawing

[0035] FIG. 1 is a process flow diagram of a method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene according to an embodiment of the present invention. Figure 2 is an image showing a fullerene included in the present invention. Specific details for implementing the invention

[0036] A method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene according to one embodiment of the present invention is,

[0037] In the process of mixing the negative electrode active material of a lead-acid battery,

[0038] A fullerene mixing step (S100) for distributing fullerene within the cathode active material by adding and mixing fullerene instead of polyester fibers when compounding lead powder, sulfuric acid, and additives according to the cathode; and

[0039] The method is characterized by including a natural aging and drying step (S200) for applying a cathode active material containing fullerene to a lead substrate and then naturally aging and drying it in the atmosphere.

[0040] At this time, the fullerene content in the above negative electrode active material is,

[0041] It is characterized by adding 1 to 5 parts by weight per 100 parts by weight of a negative electrode active material excluding fullerene.

[0042] At this time, in the fullerene mixing step (S100),

[0043] It is characterized by improving ion mobility by adding fullerene, thereby increasing the basic performance and charging efficiency of a lead-acid battery.

[0044] At this time, by the method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using the fullerene above,

[0045] It is characterized by being able to provide a 28.5% improvement in lifespan, from 238 cycles without the addition of fullerene to 306 cycles when fullerene is added.

[0046] At this time, by the manufacturing method of the present invention,

[0047] The present invention provides a lead-acid battery comprising a lead-acid battery electrode plate having a negative electrode active material for a lead-acid battery using fullerene.

[0048] Through this, not only can the basic performance of lead-acid batteries be enhanced due to the high conductivity characteristics of fullerenes, but it also provides the effect of improving the formation efficiency of lead-acid batteries.

[0049] In other words, it is expected that the efficiency of Mars can be further improved because it increases ion mobility.

[0050] Hereinafter, a method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene according to the present invention will be explained in detail through an example.

[0051] FIG. 1 is a process flow diagram of a method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene according to an embodiment of the present invention.

[0052] As illustrated in FIG. 1, the method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene according to the present invention is,

[0053] In the process of mixing the negative electrode active material of a lead-acid battery,

[0054] A fullerene mixing step (S100) for distributing fullerene within the cathode active material by adding and mixing fullerene instead of polyester fibers when compounding lead powder, sulfuric acid, and additives according to the cathode; and

[0055] The method is characterized by including a natural aging and drying step (S200) for applying a cathode active material containing fullerene to a lead substrate and then naturally aging and drying it in the atmosphere.

[0056] The fullerene described in the present invention has a symmetric and stable structure in which 60 carbon atoms are bonded in the shape of a soccer ball, as shown in FIG. 2.

[0057] Specifically, fullerenes have carbon rings in which carbon (C) atoms are arranged in a pentagon or hexagon, and it is preferable that these carbon rings are bonded to form a hollow space, and the number of carbon atoms is not limited.

[0058] That is, in the present invention, fullerene is C 60 ~ C 80 It includes not only common fullerenes with a carbon number of carbons, but also fullerene-likes with a carbon number smaller or larger than that.

[0059] Here, pseudo-fullerenes are generally defined as fullerenes (e.g., those with C12 carbon atoms). 60 ~ C 80 It means having a carbon number smaller or larger than that of fullerene, and includes in this if the carbon rings are bonded to form a hollow as described above.

[0060] In the present invention, fullerene may vary depending on the type of natural mineral.

[0061] In the present invention, fullerene is, for example, C 20 ~ C 150 It can have the number of carbon atoms, but is not limited to this.

[0062] In addition, in the present invention, the fullerene has a hollow structure in its structural form, and may have a shape such as a sphere, such as a soccer ball or a rugby ball, or a polyhedron.

[0063] Generally, regarding the production of fullerenes, they are artificially synthesized and manufactured using carbon black or graphite as raw materials through arc discharge or continuous combustion methods.

[0064] The fullerene produced in this way is incorporated into the cathode active material.

[0065] In this case, when fullerene is added instead of conventional fiber, the movement between ions is activated compared to conventional fiber due to the micropores.

[0066] In other words, it was confirmed through experiments that the high conductivity characteristics of fullerene consequently improve the efficiency of the active material and enhance charging efficiency.

[0067] In addition, the cause of lead-acid battery failure depends on the type of load and the management method during use.

[0068] The main causes of failure include active material sulfation, detachment of active material from the electrode plate, anode lattice corrosion, separator breakage, and complex factors.

[0069] In particular, for products installed in automobiles, active material sulfation accelerates depending on driving conditions and usage loads in the field, causing the active material to detach from the electrode plates and resulting in premature end of life.

[0070] Therefore, it is important to increase the reaction surface area of ​​the electrode active material, and to increase the adhesion between active materials by increasing the elongation rate.

[0071] In conclusion, adding fullerene instead of conventional fiber activates inter-ion movement compared to conventional fiber, thereby reducing ion mobility and resistance and improving the main cause of reduced basic performance.

[0072] In order to provide the above-mentioned function, the fullerene mixing step (S100) of the present invention is a step for distributing fullerene within the cathode active material by adding and mixing fullerene instead of polyester fibers when mixing lead powder, sulfuric acid, and additives according to the cathode.

[0073] At this time, in order to provide the effects of the present invention, the content of fullerene in the negative electrode active material is,

[0074] It is characterized by adding 1 to 5 parts by weight per 100 parts by weight of a negative electrode active material excluding fullerene.

[0075] Specifically, the fullerene mixing step (S100) is,

[0076] A basic negative electrode active material blending step comprising blending 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 a negative electrode additive with respect to 100 parts by weight of negative electrode active material; and

[0077] To the mixture formulated in the above basic cathode active material formulation step, 1 to 5 parts by weight of fullerene are added per 100 parts by weight of the mixture and stirred at a temperature of 85 to 95 degrees to produce 75 to 80 g / in 3 It includes a step of obtaining a fullerene-added cathode active material to obtain a cathode active material of a certain density.

[0078] If the weight of the added fullerene is less than 1 weight part, the electrical conductivity of the electrode plate is similar to that of the conventional one, so it corresponds to a small amount where it is difficult to expect performance improvement, and if it exceeds 5 weight parts, as proven in accelerated life tests, it is difficult to expect a life cycle of more than 5 weight parts, and it only provides a cause for price increase.

[0079] In order to provide the effect of experimental data, the above-mentioned negative electrode active material with a density of 75 to 80 g / in3 must be obtained. However, if the temperature is below 85 degrees, a problem arises where the density becomes lower than the above-mentioned density, making it impossible to provide the life cycle provided by the present invention. If the temperature exceeds 95 degrees, the density becomes higher than the above-mentioned density, resulting in a problem where the ion mobility decreases.

[0080] Therefore, it would be desirable to add fullerene within the aforementioned range.

[0081] Ultimately, the present invention applies fullerene, which possesses high conductivity characteristics, instead of conventional polyester-based fibers to the negative electrode active material of a lead-acid battery to improve electrical conductivity; this activates interion transport, thereby contributing to the improvement of the basic performance of the lead-acid battery.

[0082] In addition, the above natural aging and drying step (S200) is a process of applying a cathode active material containing fullerene to a lead substrate and then naturally aging and drying it in the atmosphere.

[0083] That is, a certain amount of cathode active material containing fullerene is evenly spread onto a lead substrate, and then naturally aged and dried in the air for 2 to 3 days.

[0084] As described above, to determine the effects of the present invention, the organic synthetic short fibers previously used in the active material mixing were replaced with fullerene and added in equal weight ratios to manufacture electrode plates. After aging through an aging process, basic performance and lifespan tests were conducted.

[0085] The term "conventional product" described below refers to a product manufactured using a negative plate coated with an organic synthetic short fiber included in the active material used in a lead-acid battery (BX80) manufactured by the applicant, and the term "improved product" refers to a product comprising a lead-acid battery electrode plate to which fullerene is applied through the manufacturing method of the present invention.

[0086] In addition, through subsequent processes such as assembly and formation to impart electrical conductivity to the substrate, a conventional product (containing organic synthetic staple fibers) and an improved product (containing fullerene) with a final capacity of 70Ah (20-hour rate capacity) were produced, and to prove the effectiveness of fullerene, a charge retention and 50% DoD durability test was conducted.

[0087] 1) Charge Acceptance Test (CA)

[0088] After discharging the fully charged sample at room temperature (25±2℃) for 2.5 hours at a 5-hour rate current (17.5A based on 70Ah), leave it at a temperature of 0±2℃ for at least 12 hours.

[0089] Afterwards, charge at a constant voltage of 14.4V±0.1V and measure the current after 10 minutes of charging.

[0090] As a result of the test, it was found that the improved product had higher battery conductivity and charging efficiency, and the current increased by 29% in about 10 minutes compared to the conventional product.

[0091] division hour Conventional product improved product Charging income 1 minute 27.25 29.21 2 minutes 24.21 28.77 3 minutes 22.14 28.12 4 minutes 21.25 27.92 5 minutes 20.11 27.17 6 minutes 19.35 26.82 7 minutes 18.74 25.16 8 minutes 17.68 24.89 9 minutes 17.04 22.97 10 minutes 16.93 21.92

[0092] Organic synthetic staple fibers are added to the active material to increase the mechanical strength of the battery active material.

[0093] Considering acid resistance to the aqueous sulfuric acid solution used as the electrolyte, polypropylene, polyester, and modacrylic materials are used.

[0094] The organic synthetic staple fiber used has a circular cross-section, which is the specification of a conventional synthetic staple fiber manufactured by direct spinning, has a fineness of 2 to 5 denier (diameter is about 12 to 20 micrometers), and a length of 2 to 10 millimeters.

[0095] The amount added during mixing is 0.1 to 0.5 wt%, which improves the mechanical strength of the final electrode active material and suppresses the phenomenon in which the structure of the active material is destroyed due to shrinkage and expansion of the active material caused by vibration and charging / discharging.

[0096] However, in the case of the aforementioned organic synthetic staple fibers, problems arose in providing performance in environments requiring increasingly high basic performance.

[0097] Therefore, in order to improve this, the present invention uses fullerene, which has superior ion mobility compared to polyester-based fibers.

[0098] The use of fullerenes with excellent ion mobility enables improved high output and expected lifespan, ultimately enhancing the basic performance and lifespan of the battery.

[0099] Therefore, a fullerene having the above-mentioned characteristics is introduced in the present invention, and by using a fullerene that provides high ion mobility as an additive to the cathode active material, the effect of maximizing ion mobility and increasing electrical conductivity is provided.

[0100] I will describe the experimental data regarding this later.

[0101] 2) Accelerated life testing (SAE J2801)

[0102] The lead-acid battery is subjected to 34 charge / discharge cycles in a 75°C water bath for about one week, similar to normal vehicle conditions.

[0103] After performing 34 cycles, discharge at 200A for 10 seconds, and if the voltage is maintained at 7.2V or higher, perform another 34 cycles to conduct the life test.

[0104] In addition, the test is stopped if the charging current rises above 15A or the discharge voltage drops below 12.0V during the cycle.

[0105] Table 2 below shows the results of the SAE J2801 test, and the voltage is shown when discharged at 200A for 10 seconds every 34 charge / discharge cycles.

[0106] cycling 0 parts by weight of fullerene 0.5 parts by weight of fullerene 1 part by weight of fullerene 5 parts by weight of fullerene 10 parts by weight of fullerene 34 11.82 11.81 11.98 11.99 11.99 68 11.76 11.79 11.85 11.95 11.96 102 11.72 11.75 11.79 11.91 11.93 136 11.69 11.69 11.71 11.85 11.88 170 11.65 11.65 11.68 11.80 11.85 204 11.55 11.61 11.65 11.75 11.81 238 11.43 11.45 11.63 11.71 11.70 272 7.2 or less 7.2 or less 11.61 11.65 11.63 306 7.2 or less 11.60 11.65 340 7.2 or less 7.2 or less

[0107] As shown in Table 2 above, the test results showed that when fullerene, which provides high ion mobility, is not added and when 0.5 parts by weight is added, the lifespan is 238 cycles, but when 1 part by weight is added, the lifespan is 272 cycles, and when 5 parts by weight are added, the lifespan is 306 cycles, which can provide a 28.5% improvement in lifespan.

[0108] However, it can be seen that even if fullerene is added in excess of 5 parts by weight, the lifespan does not increase further at 306 cycles. Accordingly, the most optimal range among 1 part by weight to 5 parts by weight is 2 to 5 parts by weight, so it is desirable to add within the above range.

[0109] This appears to be a result of the reduced sulfation content accumulated in the active material as charging efficiency increases due to improved ion mobility.

[0110] In other words, by showing a 28.5% improvement in lifespan compared to conventional products, it was found that the addition of fullerene, which provides high ion mobility, had a positive effect on increasing lifespan.

[0111] Through the manufacturing method described above, fullerene is added to the active material of a lead-acid battery to improve electrical conductivity within the lead-acid battery, thereby reducing electrical loss caused by resistance during charging and discharging, and providing the effect of improving the initial performance and durability of the lead-acid battery.

[0112] 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

[0113] S100: Fullerene mixing step S200: Natural aging and drying stage

Claims

Claim 1 A method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene comprises: a fullerene mixing step (S100) for distributing fullerene within the negative electrode active material by adding and mixing fullerene instead of polyester fibers when mixing lead powder, sulfuric acid, and additives according to the negative electrode in a process of mixing the negative electrode active material of a lead-acid battery; and a natural aging and drying step (S200) for applying the negative electrode active material containing fullerene to a substrate made of lead and then naturally aging and drying it in the atmosphere; wherein the fullerene mixing step (S100) comprises a basic negative electrode active material mixing step in which 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 a negative electrode additive are mixed in such a way that the sum of the lead powder, sulfuric acid, water, and negative electrode additive is 100 parts by weight; and the above A method for manufacturing an electrode plate for a lead-acid battery that improves electrical conductivity using fullerene, characterized by including a step of obtaining a fullerene-added cathode active material for obtaining a cathode active material with a density of 75 to 80 g / in³ by adding 1 to 5 parts by weight of fullerene relative to 100 parts by weight of the cathode active material blended in the basic cathode active material blending step and stirring at a temperature of 85 to 95 degrees; wherein, in the fullerene mixing step (S100), fullerene is added to improve ion mobility and increase the basic performance and charging efficiency of the lead-acid battery. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 A lead-acid battery comprising a lead-acid battery electrode plate having a negative electrode active material for a lead-acid battery using fullerene, manufactured by the method of claim 1.

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