Lead-acid battery regeneration and revival additive and lead-acid battery using the same

Abstract

To provide a regeneration and revival additive capable of reviving a used lead-acid battery by simply adding and injecting it into an electrolyte. [Solution] A regeneration and revitalization additive for lead-acid batteries, characterized by containing carbon-based microparticles of 5 μm or less, a fluorochemical surfactant or an alternative fluorochemical surfactant, and being formed as a colloidal solution diluted with water.

Description

[Technical Field]

[0001] The present invention relates to a novel regenerating and reviving additive for lead-acid batteries and a lead-acid battery using the same. [Background technology]

[0002] Lead storage batteries, a typical secondary battery, have a high output density and can handle large currents, making them suitable for use as portable power sources. They have traditionally been used to start automobile engines, as a power source for forklifts and yard transport vehicles, and as a power source for operating electrical equipment. They are also used as stationary emergency or backup power sources, as they can control the supply and stop of power in response to demand.

[0003] As shown in Figure 5, this type of lead-acid battery C uses lead oxide (PbO2) for the positive electrode, lead (Pb) for the negative electrode, and dilute sulfuric acid (H2SO4) for the electrolyte, and is configured to generate an electromotive force between the positive and negative electrodes by utilizing a chemical reaction. This electromotive force is usually 12V or 24V. When a lead-acid battery is discharged, as shown in equation (1), the lead (Pb) on the surface of the negative electrode is converted into sulfate ions (SO4 2- ) and becomes lead sulfate (PbSO4) and releases electrons (e - ) is emitted.

[0004] Pb + SO4 2- → PbSO4+ 2e - ……(1) As shown in equation (2), the positive electrode receives the electrons released from the negative electrode, and the lead oxide (PbO2) on the surface of the positive electrode reacts with sulfuric acid (H2SO4) to form lead sulfate, and when a load is connected between the positive and negative electrodes, a current flows. PbO2+ 4H + + SO4 2- + 2e - → PbSO4 + 2H2O ……(2) As a result, the overall reaction during discharge is shown in equation (3). Pb + 2H2SO4+ PbO2→ 2PbSO4+ 2H2O ……(3) On the other hand, during charging, the reactions shown in formulas (1) to (3) occur in the opposite directions to the reactions during discharging.

[0005] In this way, secondary batteries, such as lead-acid batteries, can be used for a long period of time by repeatedly charging and discharging, but they gradually lose activity and become unusable. The cause of this inhibition is that the active material on the positive and negative electrode surfaces becomes covered with lead sulfate during discharge. However, since lead sulfate is not electrically conductive, once the surfaces of both electrodes are covered with lead sulfate crystals, the charge acceptance gradually decreases and cannot be restored by charging. This phenomenon is called sulfation.

[0006] One known solution to the sulfation problem in lead-acid batteries is an additive that restores electrical capacity by adding a suspension of highly conductive carbon particles to the electrolyte. It is believed that by adding highly conductive carbon particles to the electrolyte, the carbon particles dispersed in the electrolyte penetrate into the electrode surface and the lead sulfate adhering to the electrode surface during charging, acting as a current path and promoting the chemical reaction that reduces lead sulfate to lead. However, the method of simply dispersing carbon particles in an electrolyte solution requires the addition of a large number of carbon particles to the electrolyte solution, which causes problems such as the formation of precipitates and the occurrence of problems such as short circuits, and therefore has not been put to practical use. So, as a way to solve this problem, Patent Document 1 proposes using an aqueous carbon suspension as an electrolyte, Patent Document 2 proposes a technique in which conductive fine particles such as soot, manganese dioxide, or tin oxide, and a protective colloid thereof are contained in an aqueous electrolyte solution. Furthermore, Patent Document 3 proposes a secondary battery that uses pulverized soot with a median diameter of 600 nm or less as ultrafine carbon particles, Furthermore, Patent Document 4 proposes a technique in which a dispersion composition obtained by surface-modifying fine carbon fibers and dispersing them in a polar solvent is used as an activator for lead-acid batteries. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 2736243 [Patent Document 2] Patent No. 3431438 [Patent Document 3] Patent No. 3373751 [Patent Document 4] JP 2003-59527 A DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0008] However, the carbon suspension proposed in Patent Document 1 is not an additive to the electrolyte itself, but is used in the electrolyte, and to produce the carbon suspension, the carbon particles must be subjected to electrolytic oxidation as a pretreatment. This additional step of electrolytic oxidation increases the manufacturing cost. Patent Document 1 also describes that the carbon particles are hydrophilic due to the carbonyl or carboxyl groups modified on their surfaces, which allows them to adsorb to the positive electrode during charging. However, in reality, they are difficult to adsorb to the positive electrode. Furthermore, because carbon particles are unstable in acidic electrolytes, their effectiveness disappears relatively quickly with repeated charging and discharging, resulting in poor durability. Patent Document 2 proposes an additive for secondary batteries that uses conductive fine particles and their protective colloid, but the conductive fine particles are limited to soot, manganese dioxide, tin oxide, lead oxide, or titanium oxide, and the conductive fine particles and protective colloid are either ink or a material containing ink, which makes the manufacturing process complicated and also results in high manufacturing costs. Furthermore, Patent Document 3 is a secondary battery that uses pulverized soot instead of an additive supplemented to the electrolyte solution as in Patent Document 1, and forms a conductive path by adhering carbon fine particles to the surface of the active material particles of the electrode. However, when the carbon fine particles become fine particles of the nanometer order, there are problems such as poor dispersibility in the electrolyte solution and a tendency for precipitation to occur. Furthermore, in Patent Document 4, the outer diameter, aspect ratio, and BET specific surface area of ​​the fine carbon fibers are specified to predetermined values, and the surface must be treated with a strong acid having a specific oxidizing effect. This makes it particularly difficult to produce a dispersion composition, increases the production cost, and is not practical. The inventors have conducted research and found that the above-mentioned technologies proposed for regenerating and activating lead-acid batteries using carbon microparticles involve various measures to improve the adhesion of the carbon microparticles to the electrodes and prevent precipitation, but all of these are difficult to implement due to the complex manufacturing process and high manufacturing costs.

[0009] The present inventors have conducted various studies on the above problems and have proposed the present invention to solve them. Therefore, the object of the present invention is to provide a novel regenerating and reviving additive for lead-acid batteries, which can be produced by a simple process at low production costs, and which has high dispersibility in the electrolyte and high adhesion to the electrodes, making it less likely to produce precipitates. and a lead-acid battery using this The purpose is to provide [Means for solving the problem]

[0010] In order to achieve the above object, the proposed invention is characterized by the following configuration. That is, the present invention proposed as the first invention proposes a regeneration and revitalization additive for lead-acid batteries, characterized in that a fluorochemical surfactant or an alternative fluorochemical surfactant is added to carbonaceous fine particles of 5 μm or less, the mixture is diluted and kneaded with methanol, and then pure water is added and the mixture is stirred and kneaded to form a colloidal solution. Here, the carbon-based particles are selected from carbon graphite, carbon nanotubes, fullerenes, etc., and are preferably mixed at 0.001% to 0.008% by weight of the total, 0.0001% to 0.0008% by weight of a fluorine-based or alternative fluorine-based surfactant, and 0.001% to 0.006% by weight of methanol to form a suspension, which is then diluted with a large amount of pure water (97.00% to 99.9%) to form a colloidal solution, which serves as the stock solution. Furthermore, the stock solution thus produced can be subjected to an electric field as required to improve the monomolecularization and dispersibility of the carbonaceous particles that are the dispersoid in the colloidal solution. In addition, as a second invention, a lead-acid battery utilizing the first invention is Suggested . [Effects of the Invention]

[0011] The first regeneration and revitalization additive for lead-acid batteries of the present invention (hereinafter referred to as "the additive of the present invention") can be produced through a simple process in which carbon-based fine particles of 5 μm or less are mixed with a fluorochemical surfactant or an alternative fluorochemical surfactant and methanol, and then diluted with a large amount of pure water to produce a colloidal solution, and therefore the production cost is extremely low compared to conventional additives. Furthermore, handling is simple because it is only necessary to replenish the electrolyte without removing and replacing a portion of the electrolyte. According to the inventors, it has been confirmed that replenishing the additive of the present invention increases the electrical capacity that can be extracted from the storage battery by 10 to 20% or more and significantly extends the life of the lead-acid battery. It has also been confirmed that when used on a weakened lead-acid battery (one with unbroken electrodes), it can be restored to the same level as a new battery. The lead-acid battery of the second present invention is The first invention, the regenerative revitalizer, is replenished in the electrolyte, which results in high charge / discharge efficiency, increased power, and a longer battery life. . [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a flow diagram illustrating a process for producing the additive of the present invention. [Figure 2]1 is a magnified microscopic photograph showing a comparison of lead sulfate crystals formed when the additive of the present invention is used and when it is not used. [Figure 3] 1 is a graph showing the results of a test comparing the discharge performance of a lead-acid battery using the additive of the present invention with that of a lead-acid battery not using the additive. [Figure 4] 1 is a graph comparing the electrical performance during charging of a lead-acid battery using the additive of the present invention with that of a lead-acid battery not using the additive. [Figure 5] FIG. 1 is a diagram showing the basic configuration of a lead-acid battery. BEST MODE FOR CARRYING OUT THE INVENTION

[0013] Examples of the present invention will be described below. [Example]

[0014] The manufacturing method and manufacturing process of the additive of the present invention FIG. 1 is a flow diagram showing the manufacturing process of the additive of the present invention. In the present invention, carbonaceous particles of 5 μm or less are used. As the carbon-based material, carbon graphite, carbon nanotubes, fullerenes, etc. can be used, and one or more of these are selected. The size of the carbonaceous particles need only be 5 μm or less, and does not need to be nm. Next, a fluorochemical surfactant and methanol are added to the carbon particles and kneaded. PFAS-free alternative fluorine-based surfactants can also be used. As a PFAS-free alternative fluorine-based surfactant, the MEGAFACE (registered trademark) EFS series from DIC Corporation is preferably used. The amount of fluorosurfactant or alternative fluorosurfactant added here is about 1 / 10 of the carbon-based microparticles (total weight ratio), which can increase the dispersibility of the carbon microparticles and improve their adhesion. Methanol is added in an amount of about half the amount of carbon-based particles (total weight ratio) to dilute the mixture. The resulting thick carbon suspension is poured into a pail, and a large amount of pure water, 97% or more (total weight ratio), is added to dilute it, and the mixture is mixed and stirred to produce a colloidal solution, which is used as the stock solution. Finally, an electric field is applied to the stock solution thus produced. This electric field treatment is particularly useful for increasing the dispersibility of the dispersed matter in the colloidal solution and preventing it from flocculating and settling when the carbon particles are smaller than 5 μm. This treatment is performed by placing a pail on top of the electronic mat and applying a high voltage for a specified period of time.

[0015] The blending ratio of the additive of the present invention The following shows the blending ratios (wt %) of carbon fine particles, fluorine-based surfactant, methanol, and pure water that the inventors have confirmed as preferred examples. carbon particles It is not necessary to use ultrafine particles on the order of nm, as long as they are 5 μm or less. Ultrafine particles on the order of nm tend to settle, while particles larger than 5 μm do not provide sufficient adhesion. The total content is preferably 0.001 to 0.008%, and more preferably 0.003 to 0.005%. Fluorosurfactants The total blending ratio is preferably 0.0001 to 0.0008%, and more preferably 0.0003 to 0.0005%. A fluorosurfactant substitute may be used instead of the fluorosurfactant. This fluorosurfactant has the effect of improving the dispersibility of carbon particles and increasing their adhesion to the electrode surface. methanol The content is preferably 0.001 to 0.006%, and more preferably 0.001 to 0.003%. Methanol does not adversely affect the fluorosurfactant and is useful for diluting the carbon suspension. pure water 97.00 to 99.9% is desirable, and 98.00 to 99.9% is even more desirable. The additive of the present invention is characterized in that it is diluted with a larger amount of water than other components, and the water is preferably pure water that is free from impurities such as electrolytes and minerals. The additive of the present invention does not require pretreatment of carbon fine particles as described above, and the manufacturing process is extremely simple. Moreover, only 1 to 2% of components other than pure water are required, so manufacturing costs are low.

[0016] Anti-sulfation effect FIG. 2 is a micrograph showing lead sulfate crystals that formed on the negative electrode of a lead-acid battery with an electrical capacity of 2 Ah when the battery was charged and discharged. The left side shows the case where the additive of the present invention was used, and the right side shows the case where the additive was not used. In comparison, the photograph on the left shows some coarse lead sulfate crystals B, but also many fine crystals A. In contrast, the photograph on the right shows a large number of coarse lead sulfate crystals B. According to the inventor's observations, in batteries using the additive of the present invention, during charging, the conductive carbonaceous microparticles not only efficiently disperse and adhere to the electrodes, but also penetrate into the electrodes through gaps in the coarse lead sulfate crystals already attached to the electrodes, thereby enabling electrical continuity between the electrodes and the electrolyte that was previously blocked by non-conductive lead sulfate, and increasing the surface area of ​​the electrodes in contact with the electrolyte, thereby accelerating the chemical reaction between the electrolyte and the electrodes. As a result, during charging, the reduction of lead sulfate to lead is activated, and the lead sulfate crystals are decomposed. Meanwhile, during discharge, the carbonaceous microparticles penetrate and form numerous electrical paths with the electrolyte, dispersing the locations where lead sulfate is produced and preventing the lead sulfate crystals from becoming coarse.

[0017] Discharge performance comparison test Figure 3 is a table showing the results of a test comparing the discharge performance of a lead-acid battery using the additive of the present invention with that of a lead-acid battery not using the additive. Both were 27 Ah automotive lead-acid batteries connected to the same load, and the comparison was made after three cycles of discharge. The components of the additive of the present invention were used in the desired blending ratios described in the above paragraph "0015." That is, the additive contained 0.001 to 0.008% carbon-based particles, 0.0001 to 0.0008% fluorine-based surfactant, 0.001 to 0.006% methanol, and 97.00 to 99.9% water. . ● indicates a product using the present invention, and □ indicates a comparative product not using the present invention. In the present invention, the voltage gradually decreased from an initial voltage of 13.3 V to 11.5 V after 3.8 hours, and then decreased rapidly to 10.5 V after 4.1 hours. In contrast, the comparison product showed a relatively gradual drop from 12.8V to 11.5V, but then dropped sharply, dropping to 11.5V after 2.5 hours. Comparing the two, a significant difference of 1.6 hours was observed.

[0018] Charging performance comparison test Figure 4 is a table showing the results of a test comparing the charging performance of a lead-acid battery using the additive of the present invention with that of a lead-acid battery not using the additive. Both were 27 Ah lead-acid batteries, using the same charger, and were compared after three cycles of discharge. ● indicates a product using the present invention, and □ indicates a comparative product not using the present invention. In the present invention, the initial voltage rises from 12V to 12.8V in an instant, then rises gradually, reaching 16.3V after 4.5 hours of full charge. In contrast, the comparative product rose from the same 12V to 12.8V in an instant, then rose to 15.9V at a faster rate than the present invention, reaching 15.9V after 3 hours, and was almost fully charged. Comparing the two, the comparative product reaches a full charge voltage of 15.9V more quickly than the product of the present invention, but the voltage of the present invention when fully charged is 16.3V, and the electric capacity is higher.

[0019] The lead-acid battery of the present invention The lead battery of the present invention uses a basic structure that is conventionally known, and the basic principle is the same as that shown in Fig. 5. Depending on the intended use, such as a passenger car or forklift, there are electromotive forces of 12V and 24V. The lead-acid battery of the present invention is prepared by filling the dilute sulfuric acid electrolyte of both new and used lead-acid batteries with the additive of the present invention, which increases the electrical capacity of new lead-acid batteries and extends the product life of used lead-acid batteries. This is particularly beneficial for lead-acid batteries compatible with idling stop systems.

[0020] How to regenerate a lead-acid battery To explain using a 12V lead-acid battery installed in a passenger car, The filler cap of the lead acid battery cell is opened and the additive is poured in in an amount that meets the specifications of the battery. In the case of the embodiment of the present invention, the additive may be added in an amount of 5 to 7 cc per liter of electrolyte. After refilling the additive, close the filler cap and then charge the battery immediately. This charging is done to attach the additive carbon particles to the electrodes of the lead battery, and can be done using a charger, or by starting the engine and idling it for about 30 minutes or by driving it normally. In other words, the additive of the present invention is extremely easy to handle, since it is not necessary to replace a portion of the electrolyte, and all that is required is to replenish the electrolyte with an appropriate amount and then charge the battery immediately after replenishment. [Explanation of symbols]

[0021] A, B Lead sulfate crystals C Lead-acid battery

Claims

1. The colloidal solution is formed from carbon-based particles of 5 μm or less, selected from one or more of carbon graphite, carbon nanotubes, and fullerenes, a fluorine-based surfactant, methanol, and water, and the total weight ratio is: The carbon-based fine particles are 0.001 to 0.008% The fluorochemical surfactant is 0.0001 to 0.0008%, The methanol is 0.001 to 0.006%, A regenerating and revitalizing additive for lead-acid batteries containing 97.00 to 99.9% of water.

2. A colloidal solution containing carbon-based particles of 5 μm or less, selected from one or more of carbon graphite, carbon nanotubes, and fullerenes, an alternative fluorine-based surfactant, methanol, and water, in a total weight ratio of: The carbon-based fine particles are 0.001 to 0.008% The alternative fluorine-based surfactant is 0.0001 to 0.0008%, The methanol is 0.001 to 0.006%, A regenerating and revitalizing additive for lead-acid batteries containing 97.00 to 99.9% of water.

3. A lead-acid battery in which the regeneration and revival additive for lead-acid batteries described in claim 1 or 2 is added to the electrolyte.

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