lead-acid battery

Abstract

DEPCT63 A lead-acid battery consists of a negative plate, a positive plate, and an electrolyte solution. The negative electrode consists of a negative electrode material composed of carbon material and an organic carbon expander. It consists of carbon-1 material with particle sizes larger than or equal to 32 micrometers and carbon material. The second factor, with particle sizes smaller than 32 micrometers, is the ratio between the powder's resistance (R2) and the material's resistance. The ratio of carbon 2 to the powder resistance R1 of carbon 1 material is R2 / R1, which is greater than or equal to 15. Less than or equal to 155 organic expanders containing lignin, sulfonic acid, or salts of that. The presence of organic expanders in the negative electrode material is greater than or equal to 0.03%. Less than or equal to 0.8% by mass. The image selected is Image 1. -----------------------------------------------------------

Description

lead acid battery

[0001] The present invention relates to a lead-acid battery.

[0002] Lead-acid batteries are used in a variety of applications, including automotive and industrial applications. A lead-acid battery includes a negative electrode plate, a positive electrode plate, and an electrolyte. The negative electrode plate includes a negative electrode current collector and a negative electrode material. An organic shrinkage preventer is added to the negative electrode material. For example, Patent Document 1 proposes adding lignosulfonate to a negative electrode active paste material in the production of a negative electrode plate.

[0003] Special table 2014-527682 publication

[0004] Lead-acid batteries are sometimes used in a state of insufficient charge called a partial state of charge (PSOC). For example, lead-acid batteries are often used in a PSOC state when used as a power source for starting automobiles or motorcycles, such as charge-controlled vehicles or idle-stop (IS) vehicles, or as an industrial power storage device for storing natural energy such as solar or wind power. Therefore, lead-acid batteries are required to have a long life in the PSOC cycle.

[0005] Increasing the amount of carbon black added to the negative electrode material is effective in improving PSOC life performance. However, because the organic shrinkage inhibitor lignin (lignosulfonic acid or its salt) is adsorbed by carbon black, adding a large amount of carbon black reduces the specific surface area of ​​the negative electrode material, resulting in a decrease in low-temperature high-rate performance. Increasing the amount of lignin is considered to suppress the decrease in low-temperature high-rate performance. However, adding a large amount of lignin reduces charge acceptance. Thus, it is difficult to improve PSOC life performance without impairing low-temperature high-rate performance and charge acceptance.

[0006] One aspect of the present invention relates to a lead-acid battery including: a negative electrode plate; a positive electrode plate; and an electrolyte; the negative electrode plate includes a negative electrode material containing a carbon material and an organic shrinkage preventer; the carbon material includes a first carbon material having a particle size of 32 μm or more; and a second carbon material having a particle size of less than 32 μm; a ratio of a powder resistance R2 of the second carbon material to a powder resistance R1 of the first carbon material: R2 / R1 is 15 or more and 155 or less; the organic shrinkage preventer includes lignosulfonic acid or a salt thereof; and a content of the organic shrinkage preventer in the negative electrode material is 0.03 mass % or more and 0.8 mass % or less.

[0007] According to the present invention, in a lead-acid battery, the PSOC life performance can be improved without impairing the low-temperature high-rate performance and charge acceptance performance.

[0008] 1 is a partially cutaway exploded perspective view showing the appearance and internal structure of a lead-acid battery according to an embodiment of the present invention.

[0009] One aspect of the present invention is a lead-acid battery comprising a negative electrode plate, a positive electrode plate, and an electrolyte. The negative electrode plate includes a negative electrode material containing a carbon material and an organic shrinkage preventer. The carbon material includes a first carbon material having a particle diameter of 32 μm or more and a second carbon material having a particle diameter of less than 32 μm, and the ratio of the powder resistance R2 of the second carbon material to the powder resistance R1 of the first carbon material (R2 / R1) is 15 or more and 155 or less. The organic shrinkage preventer includes lignin (lignosulfonic acid or a salt thereof), and the content of the organic shrinkage preventer in the negative electrode material is 0.03 mass% or more and 0.8 mass% or less.

[0010] By using a combination of two types of carbon materials with different particle sizes and powder resistivity ratios within a specific range together with a small amount of organic shrinkage inhibitor, it is possible to improve life performance in PSOC cycles.By using a combination of two types of carbon materials with different particle sizes and powder resistivity ratios within a specific range, it is possible to maintain high low-temperature high-rate performance even with a small amount of organic shrinkage inhibitor added, from 0.03 mass% to 0.8 mass%.Because the amount of organic shrinkage inhibitor added is a small amount, at 0.8 mass% or less, a decrease in charge acceptance performance due to an increase in the amount of organic shrinkage inhibitor added is avoided.

[0011] Carbon materials are known to have various powder resistances. It is known that the powder resistance of a powder material varies depending on the particle shape, particle diameter, internal structure of the particles, and / or crystallinity of the particles. According to conventional technical knowledge, the powder resistance of a carbon material has no direct relationship with the resistance of a negative electrode plate, and is not considered to have any effect on PSOC life performance and low-temperature high-rate performance.

[0012] In contrast, according to the above-described aspect of the present invention, the low-temperature high-rate performance can be improved by using a combination of a first carbon material and a second carbon material having different particle sizes and a powder resistivity ratio within a specific range together with a small amount of an organic shrinkage inhibitor. This is thought to be because, when the first carbon material and the second carbon material are used in combination, adsorption of the organic shrinkage inhibitor to the carbon material is suppressed compared to when the amount of the second carbon material is increased, and therefore the pore structure of the negative electrode material is maintained even with a small amount of the organic shrinkage inhibitor.

[0013] In the above aspect of the present invention, high PSOC life performance can be achieved by controlling the powder resistivity ratio R2 / R1 between the first carbon material and the second carbon material contained in the negative electrode plate to a range of 15 to 155. This is presumably due to the following reasons. First, controlling the powder resistivity ratio R2 / R1 to the above range facilitates the formation of a conductive network in the negative electrode material. Furthermore, even with a small amount of organic shrinkage preventer, the effect of the organic shrinkage preventer is fully exerted, and the pore structure of the negative electrode material is maintained. Therefore, the formed conductive network is easily maintained even after PSOC cycles. In other words, it can be said that the effect of the organic shrinkage preventer is enhanced by combining a first carbon material and a second carbon material having the above powder resistivity ratio.

[0014] (Organic shrink-proofing agent) The organic shrink-proofing agent includes lignin (lignosulfonic acid or its salt). Examples of the salt of lignosulfonic acid include alkali metal salts such as sodium salt. Note that lignin also includes its derivatives. For example, a product called "Vanilex N" manufactured by Nippon Paper Industries Co., Ltd. is used.

[0015] The content of the organic shrinkage inhibitor in the negative electrode material is 0.03% by mass or more and 0.8% by mass or less. If the content of the organic shrinkage inhibitor in the negative electrode material is less than 0.03% by mass, low-temperature high-rate performance is reduced. If the content of the organic shrinkage inhibitor in the negative electrode material is more than 0.8% by mass, charge acceptance performance is reduced. The content of the organic shrinkage inhibitor in the negative electrode material is the content in the negative electrode material extracted from a fully charged lead-acid battery prepared using the method described below.

[0016] The content of the organic shrinkage inhibitor in the negative electrode material is preferably 0.03% by mass or more, more preferably 0.25% by mass or more, and preferably 0.4% by mass or less. These upper and lower limits can be arbitrarily combined. In this case, a good balance of excellent PSOC life performance, low-temperature high-rate performance, and charge acceptance performance can be obtained.

[0017] The analytical methods for organic shrink-proofing agents and the methods for determining their physical properties are described below. (A) Analysis of Organic Shrink-Proofing Agents (A-1) Identification of the Organic Shrink-Proofing Agent Species The organic shrink-proofing agent species in the negative electrode material are identified as follows. A fully charged lead-acid battery is disassembled, the negative electrode plate is removed, washed with water to remove sulfuric acid, and vacuum dried (dried under a pressure lower than atmospheric pressure). The negative electrode material containing the active material is separated from the negative electrode plate, and the negative electrode material is immersed in a 1 mol / L NaOH aqueous solution to extract the organic shrink-proofing agent. The extract is then desalted by filtering to remove insoluble components, and the solution is then freeze-dried to obtain a powder sample. A desalting column or ion exchange membrane is used for desalting. The organic shrink-proofing agent species is identified using information obtained from infrared spectroscopy and NMR spectroscopy measured using the obtained powder sample of the organic shrink-proofing agent, as well as UV-visible absorption spectroscopy measured by diluting the powder sample with distilled water using a UV-visible spectrophotometer.

[0018] In this specification, the fully charged state of a lead-acid battery refers to a state in which, in the case of a flooded lead-acid battery, the battery is charged in a water tank at 25°C at a constant current of 0.2 CA until a voltage of 2.5 V / cell is reached, followed by a further constant current charge of 0.2 CA for 2 hours. In the case of a valve-regulated battery, the fully charged state refers to a state in which the battery is charged in an air tank at 25°C at a constant current and constant voltage of 0.2 CA to a voltage of 2.23 V / cell, and charging is terminated when the charging current during constant voltage charging drops to 1 mCA or less. In this specification, 1 CA refers to the current value (A) that is the same as the nominal capacity (Ah) of the battery. For example, for a battery with a nominal capacity of 30 Ah, 1 CA is 30 A, and 1 mCA is 30 mA.

[0019] (A-2) Measurement of the Content of Organic Shrinkage-Proof Agent The content of the organic shrinkage-proofing agent in the negative electrode material is measured as follows. A fully charged lead-acid battery is disassembled, the negative electrode plate is removed, washed with water to remove sulfuric acid, and vacuum dried (dried under a pressure lower than atmospheric pressure). The negative electrode material is separated from the negative electrode plate, and 100 g of the negative electrode material is immersed in 300 mL of a 1 mol / L NaOH aqueous solution to extract the organic shrinkage-proofing agent. Insoluble components are then removed from the extract by filtration, and the ultraviolet-visible absorption spectrum is measured, and the content of the organic shrinkage-proofing agent in the negative electrode material is measured using a previously prepared calibration curve.

[0020] When a battery manufactured by another company is obtained and the content of the synthetic shrink-proof agent is measured, if the structural formula of the organic shrink-proof agent cannot be precisely identified and therefore the same organic shrink-proof agent cannot be used for a calibration curve, a calibration curve is created using a separately available organic shrink-proof agent that shows similar shapes in the ultraviolet-visible absorption spectrum, infrared spectroscopy spectrum, NMR spectrum, etc. to the organic shrink-proof agent extracted from the negative electrode of the battery, and the content of the organic shrink-proof agent is measured using the visible absorption spectrum.

[0021] (Carbon material) The carbon material includes a first carbon material having a particle diameter of 32 μm or more and a second carbon material having a particle diameter of less than 32 μm. The first carbon material and the second carbon material are separated and distinguished by the procedure described below.

[0022] Examples of the carbon materials include carbon black, graphite, hard carbon, soft carbon, etc. Examples of carbon black include acetylene black, ketjen black, furnace black, lamp black, etc. The graphite may be any carbon material containing a graphite-type crystal structure, and may be either artificial graphite or natural graphite.

[0023] In addition, among the first carbon materials, the Raman spectrum of 1300 cm -1 1350cm or more -1 The peaks appearing in the following range (D band) and 1550 cm -1 More than 1600cm -1 Intensity ratio I to the peak (G band) appearing in the following range Ｄ / I Ｇ is 0 or more and 0.9 or less, the graphite is considered to be graphite.

[0024] The ratio of the powder resistance R2 of the second carbon material to the powder resistance R1 of the first carbon material (R2 / R1) is 15 or more and 155 or less. The larger the powder resistance ratio R2 / R1, the smaller the amount of lignin adsorbed by the carbon material. When the powder resistance ratio R2 / R1 is less than 15, low-temperature high-rate performance is reduced. When the powder resistance ratio R2 / R1 is more than 155, charge acceptance performance is reduced. R2 / R1 can be adjusted, for example, by changing the type, particle size, specific surface area, and / or aspect ratio of each carbon material used to prepare the negative electrode material. The first carbon material is preferably at least one selected from the group consisting of graphite, hard carbon, and soft carbon. In particular, the first carbon material preferably contains at least graphite. The second carbon material preferably contains at least carbon black. Using these carbon materials makes it easy to adjust the powder resistance ratio R2 / R1.

[0025] The powder resistance ratio R2 / R1 is preferably 50 or more and 110 or less. In this case, excellent PSOC life performance, low-temperature high-rate performance, and charge acceptance performance can be obtained in a well-balanced manner. When the powder resistance ratio R2 / R1 is 50 or more, the PSOC life performance and charge acceptance performance can be further improved. When the powder resistance ratio R2 / R1 is 110 or more, the PSOC life performance and low-temperature high-rate performance can be further improved.

[0026] When the content of the organic shrinkage preventer in the negative electrode material is 0.03% by mass or more and 0.25% by mass or less, the powder resistance ratio R2 / R1 is preferably 80 or more and 155 or less, and more preferably 80 or more and 110 or less. When the content of the organic shrinkage preventer in the negative electrode material is 0.4% by mass or more and 0.8% by mass or less, the powder resistance ratio R2 / R1 is preferably 15 or more and 85 or less, and more preferably 50 or more and 85 or less. When the content of the organic shrinkage preventer in the negative electrode material is in the above-mentioned range and the powder resistance ratio R2 / R1 are in the above-mentioned range, the PSOC life performance can be further improved.

[0027] The ratio of the specific surface area S2 of the second carbon material to the specific surface area S1 of the first carbon material (S2 / S1) is, for example, 10 or more and 400 or less. The specific surface area ratio S2 / S1 is preferably 20 or more and 240 or less. In this case, excellent PSOC life performance, low-temperature high-rate performance, and charge acceptance performance are obtained in a well-balanced manner. When the specific surface area ratio S2 / S1 is 20 or more, the PSOC life performance can be further improved. When the specific surface area ratio S2 / S1 is 240 or less, the specific surface areas of the carbon materials are within an appropriate range, thereby further suppressing adsorption of the organic shrinkage inhibitor, thereby further improving low-temperature high-rate performance. When the specific surface area ratio S2 / S1 is 20 or more and 240 or less, the reduction reaction of lead sulfate easily proceeds, thereby further improving charge acceptance performance while maintaining high PSOC life performance. The specific surface area ratio S2 / S1 is preferably 100 or more and 240 or less, and more preferably 110 or more and 240 or less. In this case, the PSOC life performance and charge acceptance performance can be further improved while maintaining low-temperature high-rate performance.

[0028] The average aspect ratio of the first carbon material is, for example, 1 or more and 200 or less. The average aspect ratio of the first carbon material is preferably 1 or more, more preferably 1.5 or more. It is also preferably 100 or less, more preferably 35 or less, and even more preferably 30 or less. These upper and lower limits can be combined arbitrarily. When the average aspect ratio of the first carbon material is 1.5 or more and 30 or less, PSOC life performance can be further improved while maintaining good low-temperature high-rate performance and charge acceptance performance. This is thought to be because when the average aspect ratio is in this range, a conductive network is easily formed in the negative electrode material and the formed conductive network is easily maintained.

[0029] Furthermore, when the average aspect ratio of the first carbon material is 1.5 or more, outflow of the carbon material into the electrolyte due to repeated charge and discharge is suppressed, thereby further enhancing the effect of improving PSOC life performance. Furthermore, when the average aspect ratio of the first carbon material is 30 or less, adhesion between the active material particles is easily ensured, thereby suppressing the occurrence of cracks in the negative electrode plate and suppressing a decrease in life performance.

[0030] The content of the first carbon material in the negative electrode material is, for example, 0.05% by mass or more and 3.0% by mass or less, preferably 0.1% by mass or more, and more preferably 0.4% by mass or more. It is also preferably 2.0% by mass or less. These upper and lower limits can be arbitrarily combined. When the content of the first carbon material in the negative electrode material is 0.05% by mass or more, the PSOC life performance can be further improved. When the content of the first carbon material in the negative electrode material is 3.0% by mass or less, adhesion between active material particles can be easily ensured, thereby suppressing the occurrence of cracks in the negative electrode plate and suppressing a decrease in life performance.

[0031] The content of the second carbon material in the negative electrode material is, for example, 0.03% by mass or more and 3.0% by mass or less, preferably 0.05% by mass or more. It is also preferably 1.0% by mass or less, and more preferably 0.5% by mass or less. These upper and lower limits can be arbitrarily combined. When the content of the second carbon material in the negative electrode material is 0.03% by mass or more, the PSOC life performance can be further improved. When the content of the second carbon material in the negative electrode material is 3.0% by mass or less, the amount of adsorption of the organic shrinkage inhibitor is further reduced, thereby further improving the low-temperature high-rate performance. The content of each carbon material in the negative electrode material is determined by the procedure (B-1) described below.

[0032] The methods for determining or analyzing the physical properties of carbon materials are described below. (B) Analysis of Carbon Materials (B-1) Separation of Carbon Materials: A fully charged lead-acid battery is disassembled, the pre-formed negative electrode plate is removed, washed with water to remove sulfuric acid, and vacuum dried (dried under a pressure lower than atmospheric pressure). Next, the negative electrode material is collected from the dried negative electrode plate and pulverized. 30 mL of a 60% by weight aqueous nitric acid solution is added to 5 g of the pulverized sample and heated to 70°C. 10 g of disodium ethylenediaminetetraacetate, 30 mL of a 28% by weight aqueous ammonia, and 100 mL of water are then added, and heating is continued to dissolve the soluble components. The pretreated sample is then recovered by filtration. The recovered sample is passed through a 500 μm sieve to remove large components such as reinforcing materials, and the components that pass through the sieve are recovered as carbon material.

[0033] When the recovered carbon material is wet sieved using a sieve with 32 μm mesh, the material that does not pass through the sieve and remains on the sieve is called the first carbon material, and the material that passes through the sieve is called the second carbon material. In other words, the particle size of each carbon material is based on the size of the sieve mesh. For wet sieving, JIS Z8815:1994 can be referenced.

[0034] Specifically, the carbon material is placed on a sieve with 32 μm mesh size, and sieved by gently shaking the sieve for 5 minutes while spraying ion-exchanged water. The first carbon material remaining on the sieve is recovered from the sieve by pouring ion-exchanged water over it, and separated from the ion-exchanged water by filtration. The second carbon material that passed through the sieve is recovered by filtration using a nitrocellulose membrane filter (0.1 μm mesh size). The recovered first carbon material and second carbon material are each dried at a temperature of 110°C for 2 hours. The 32 μm mesh size sieve used is one equipped with a sieve mesh with a nominal mesh size of 32 μm, as specified in JIS Z 8801-1:2006.

[0035] The content of each carbon material in the negative electrode material is determined by measuring the mass of each carbon material separated by the above procedure and calculating the proportion (mass %) of this mass in 5 g of the pulverized sample.

[0036] (B-2) Powder Resistivity of Carbon Materials The powder resistance R1 of the first carbon material and the powder resistance R2 of the second carbon material are values ​​measured by the four-probe method for each of the first carbon material and the second carbon material separated by the procedure in (B-1) above, by putting 0.5 g of a sample into a powder resistance measurement system (MCP-PD51 model, manufactured by Mitsubishi Chemical Analytech Co., Ltd.) and using a low-resistance resistivity meter (Loresta-GX MCP-T700, manufactured by Mitsubishi Chemical Analytech Co., Ltd.) in accordance with JIS K 7194:1994 under a pressure of 3.18 MPa.

[0037] (B-3) Specific Surface Area of ​​Carbon Materials The specific surface area S1 of the first carbon material and the specific surface area S2 of the second carbon material are the BET specific surface areas of the first carbon material and the second carbon material, respectively. The BET specific surface area is determined by a gas adsorption method using the BET equation, using each of the first carbon material and the second carbon material separated by the procedure (B-1) above. Each carbon material is pretreated by heating at a temperature of 150°C for 1 hour in a nitrogen flow. Using the pretreated carbon material, the BET specific surface area of ​​each carbon material is determined using the following apparatus and under the following conditions. Measuring apparatus: TriStar 3000 manufactured by Micromeritics, Inc. Adsorption gas: nitrogen gas with a purity of 99.99% or higher Adsorption temperature: boiling point of liquid nitrogen (77K) Calculation method of BET specific surface area: in accordance with 7.2 of JIS Z 8830:2013

[0038] (B-4) Average aspect ratio of the first carbon material The first carbon material separated by the procedure (B-1) above is observed with an optical microscope or an electron microscope, and 10 or more particles are randomly selected and enlarged photographs are taken. Next, the photographs of each particle are processed to determine the maximum particle diameter d1 and the maximum particle diameter d2 in a direction perpendicular to the maximum diameter d1. The aspect ratio of each particle is calculated by dividing d1 by d2. The obtained aspect ratios are averaged to calculate the average aspect ratio.

[0039] The utilization rate of the negative electrode plate is preferably 40% or more and 70% or less, more preferably 50% or more. It is also preferably 70% or less, and even more preferably 65% ​​or less. These upper and lower limits can be arbitrarily combined. Increasing the utilization rate of the negative electrode plate reduces the amount of negative electrode active material, thereby reducing costs. However, because the negative electrode active material is overworked during charging and discharging, deterioration of the negative electrode plate due to sulfation and other factors tends to progress, resulting in a decrease in battery performance, such as low-temperature high-rate performance and PSOC life performance. On the other hand, even when the utilization rate of the negative electrode plate is high, battery performance, such as PSOC life performance, can be significantly improved by using a negative electrode material containing a small amount of lignin within a specific range and two types of carbon materials with different particle sizes and powder resistivity ratios within a specific range. For example, when increasing the utilization rate of the negative electrode plate to 50% or more, increasing the powder resistivity ratio R2 / R1 to 100 or more can significantly improve low-temperature high-rate performance and PSOC life performance.

[0040] (C) The method for measuring the utilization rate of the negative electrode plate is explained below. The utilization rate of the negative electrode plate can be calculated using the following formula: Utilization rate of negative electrode plate (%) = (nominal capacity / negative electrode theoretical capacity) × 100 The theoretical capacity of the negative electrode can be calculated using the following formula: Negative electrode theoretical capacity (Ah) = mass (g) of negative electrode active material in negative electrode plate × theoretical capacity (Ah) per 1 g of negative electrode active material The theoretical capacity per 1 g of negative electrode active material (Pb) is 0.259 Ah. The smaller the mass of the negative electrode active material, the higher the utilization rate of the negative electrode.

[0041] The mass of the negative electrode active material in the negative electrode plate can be determined using the following procedure. First, a fully charged battery is disassembled, the negative electrode plate is removed, washed with water, and vacuum dried (dried under a pressure lower than atmospheric pressure), and the mass of the negative electrode plate is measured. Next, the negative electrode material containing the negative electrode active material is separated from the negative electrode plate, and the mass of the remaining negative electrode current collector (negative electrode grid) is measured. The difference between the mass of the negative electrode plate and the mass of the negative electrode grid is calculated as the mass of the negative electrode material.

[0042] The negative electrode material separated from the negative electrode plate was pulverized, and 20 mL of hydrogen peroxide solution (concentration 300 g / L) was added per 100 g of negative electrode material. Nitric acid was then added and the mixture was heated with stirring for 5 hours. In this way, the lead contained in the negative electrode material was dissolved as lead nitrate. The nitric acid used was concentrated nitric acid (concentration 60% by mass) diluted with ion-exchanged water. The volume ratio of concentrated nitric acid to ion-exchanged water was 1:3. The remaining additives (carbon material, organic shrinkage inhibitor, barium sulfate, reinforcing material, etc.) that did not dissolve in the nitric acid were separated by filtration, washed with water, dried, and then the mass of the additives was measured. The difference between the mass of the negative electrode material and the mass of the additives was calculated as the mass of the negative electrode active material.

[0043] Lead-acid batteries according to embodiments of the present invention will be described below by their main components, but the present invention is not limited to the following embodiments. (Negative Electrode Plate) The negative electrode plate of a lead-acid battery includes a negative electrode material. The negative electrode plate is typically composed of a negative electrode grid (negative electrode current collector) and a negative electrode material. The negative electrode material is the negative electrode plate excluding the negative electrode current collector. The negative electrode plate may have a mat, pasting paper, or other member attached thereto. If the negative electrode plate includes such a member (attaching member), the negative electrode material is the negative electrode material excluding the negative electrode current collector and the adhesive member. However, the thickness of the electrode plate includes the thickness of the mat. If a mat is attached to the separator, the thickness of the mat is included in the thickness of the separator.

[0044] The negative electrode material includes a negative electrode active material (lead or lead sulfate) that exhibits capacity through an oxidation-reduction reaction. The negative electrode active material in a charged state is sponge lead, but an unformed negative electrode plate is usually made using lead powder. The negative electrode material also includes a carbon material and an organic shrinkage inhibitor. The negative electrode material may further include barium sulfate, and may also include other additives as necessary. The content of barium sulfate in the negative electrode material is, for example, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, 0.5% by mass or more, 1.0% by mass or more, or 1.3% by mass or more. On the other hand, it is preferably 3.0% by mass or less, more preferably 2.5% by mass or less, and even more preferably 2% by mass or less. These lower and upper limits can be combined arbitrarily.

[0045] The following describes a method for quantifying barium sulfate contained in the negative electrode material. Prior to quantitative analysis, a lead-acid battery after chemical formation is fully charged and then disassembled to obtain a negative electrode plate to be analyzed. The obtained negative electrode plate is washed with water and dried to remove the electrolyte from the negative electrode plate. Next, the negative electrode material is separated from the negative electrode plate to obtain an unpulverized initial sample.

[0046] An unpulverized initial sample is pulverized, and 50 ml of (1+2) nitric acid is added to 10 g of the pulverized initial sample, and the mixture is heated for about 20 minutes to dissolve the lead component as lead nitrate. Next, the solution containing lead nitrate is filtered to separate out solid components such as carbonaceous materials and barium sulfate.

[0047] The obtained solid content is dispersed in water to form a dispersion, and then components other than the carbonaceous material and barium sulfate (e.g., reinforcing material) are removed from the dispersion using a sieve. Next, the dispersion is subjected to suction filtration using a membrane filter whose mass has been measured in advance, and the membrane filter is dried together with the filtered sample in a dryer at 110°C. The filtered sample is a mixed sample of the carbonaceous material and barium sulfate. The mass (A) of the mixed sample is measured by subtracting the mass of the membrane filter from the total mass of the dried mixed sample and membrane filter. The dried mixed sample is then placed in a crucible together with the membrane filter and incinerated at 700°C or higher. The remaining residue is barium oxide. The mass of barium oxide is converted to the mass of barium sulfate to determine the mass (B) of barium sulfate.

[0048] The density of the negative electrode material is, for example, 2.4 to 5 g / cm 3 From the viewpoint of reducing the weight of lead-acid batteries, the density of the negative electrode material can be adjusted within the range of 2.4 to 4.0 g / cm 3Preferably, the density of the negative electrode material refers to the bulk density of the negative electrode material in a fully charged state after chemical formation, and is measured as follows. The battery after chemical formation is fully charged and then disassembled, and the obtained negative electrode plate is washed with water and dried under vacuum or in an inert gas atmosphere to remove the electrolyte from the negative electrode plate. Next, the negative electrode material is separated from the negative electrode plate to obtain an unpulverized measurement sample. The sample is placed in a measurement container, evacuated, and then filled with mercury at a pressure of 0.5 to 0.55 psia. The bulk volume of the negative electrode material is measured, and the mass of the measurement sample is divided by the bulk volume to determine the bulk density of the negative electrode material. The bulk volume is the volume of the measurement container minus the volume of mercury injected.

[0049] The negative electrode current collector may be formed by casting lead (Pb) or a lead alloy, or by processing a lead or lead alloy sheet, for example, by expanding or punching.

[0050] The lead alloy used for the negative electrode current collector may be any of a Pb—Sb alloy, a Pb—Ca alloy, and a Pb—Ca—Sn alloy. These lead or lead alloys may further contain at least one element selected from the group consisting of Ba, Ag, Al, Bi, As, Se, Cu, etc. as an additive element.

[0051] The negative electrode plate can be formed by filling a negative electrode current collector with a negative electrode paste, aging and drying it to produce an unformed negative electrode plate, and then chemically forming the unformed negative electrode plate. The negative electrode paste is produced by adding water and sulfuric acid to lead powder, an organic shrinkage inhibitor, a carbon material, and various additives as needed, and kneading them.

[0052] The formation can be performed by charging an unformed negative electrode plate immersed in an electrolyte containing sulfuric acid. The formation may be performed in a battery container after the lead-acid battery is assembled, or may be performed in a separate formation container containing an electrolyte before the lead-acid battery or the electrode plate group is assembled.

[0053] (Positive Electrode Plate) Positive electrode plates for lead-acid batteries are classified into paste type and clad type. Paste type positive electrode plates include a positive electrode current collector and a positive electrode material. The positive electrode material is held by the positive electrode current collector. The positive electrode current collector may be formed in the same manner as the negative electrode current collector, and can be formed by casting lead or a lead alloy or processing a lead or lead alloy sheet.

[0054] A clad positive electrode plate includes multiple porous tubes, a metal core inserted into each tube, a current collector connecting the metal cores, a positive electrode material filled into the tubes with the metal cores inserted, and a connecting seat connecting the multiple tubes. The metal cores and the current collector connecting the metal cores are collectively called the positive electrode current collector.

[0055] Examples of lead alloys used for the positive electrode current collector include Pb—Ca-based alloys, Pb—Sb-based alloys, and Pb—Ca—Sn-based alloys. The lead alloy may further contain at least one element selected from the group consisting of Ba, Ag, Al, Bi, As, Se, and Cu as an additive element. The positive electrode current collector may have lead alloy layers with different compositions, or the number of alloy layers may be multiple. For the core metal, Pb—Ca-based alloys, Pb—Sb-based alloys, and the like are used.

[0056] The positive electrode material contains a positive electrode active material (lead dioxide, lead sulfate, lead monoxide) that generates capacity through an oxidation-reduction reaction. The positive electrode material may contain other additives as needed.

[0057] The unformed paste-type positive electrode plate is obtained by filling a positive electrode paste made by adding lead powder, various additives, water, and sulfuric acid to a positive electrode current collector, aging it, and drying it. When aging, it is preferable to age the unformed positive electrode plate at a temperature higher than room temperature and at a high humidity. Then, the unformed positive electrode plate is formed.

[0058] The clad type positive electrode plate is formed by filling a tube with lead powder or lead powder slurry into a core metal inserted into the tube, and then joining a plurality of the tubes together with a connecting member.

[0059] (Separator) A separator is usually placed between the negative electrode plate and the positive electrode plate. Nonwoven fabrics, microporous membranes, etc. are used as the separator. The thickness and number of separators to be interposed between the negative electrode plate and the positive electrode plate may be selected according to the inter-electrode distance. Nonwoven fabrics are mats in which fibers are intertwined without being woven, and are primarily composed of fibers. For example, 60% or more by mass of the separator is formed from fibers. Examples of fibers that can be used include glass fibers, polymer fibers (polyolefin fibers, acrylic fibers, polyester fibers such as polyethylene terephthalate fibers), and pulp fibers. Among these, glass fibers are preferred. The nonwoven fabric may contain components other than fibers, such as acid-resistant inorganic powders and polymers as binders.

[0060] On the other hand, a microporous membrane is a porous sheet mainly composed of components other than fiber components, and can be obtained, for example, by extruding a composition containing a pore-forming agent (such as a polymer powder and / or oil) into a sheet, and then removing the pore-forming agent to form pores. Microporous membranes are preferably made of acid-resistant materials, and are preferably composed mainly of polymer components. The polymer component is preferably a polyolefin such as polyethylene or polypropylene.

[0061] The separator may be made of, for example, only a nonwoven fabric or only a microporous membrane. Furthermore, the separator may be a laminate of a nonwoven fabric and a microporous membrane, a laminate of different or the same materials, or a laminate of different or the same materials with recesses and protrusions interlocked, as needed.

[0062] (Electrolyte) The electrolyte is an aqueous solution containing sulfuric acid, and may be gelled as necessary. The specific gravity of the electrolyte at 20°C in a lead-acid battery in a fully charged state after formation is, for example, 1.10 to 1.35 g / cm 3 and 1.20 to 1.35 g / cm 3 It is preferable that:

[0063] FIG. 1 shows the external appearance of an example of a lead-acid battery according to an embodiment of the present invention. The lead-acid battery 1 includes a battery case 12 that contains a plate pack 11 and an electrolyte (not shown). The battery case 12 is divided into multiple cell chambers 14 by partition walls 13. Each cell chamber 14 contains one plate pack 11. The opening of the battery case 12 is sealed with a lid 15 that includes a negative electrode terminal 16 and a positive electrode terminal 17. The lid 15 is provided with a vent plug 18 for each cell chamber. When rehydrating, the vent plug 18 is removed and rehydration solution is added. The vent plug 18 may have the function of venting gas generated in the cell chambers 14 to the outside of the battery.

[0064] Each electrode plate group 11 is formed by stacking a plurality of negative electrode plates 2 and positive electrode plates 3 with separators 4 interposed therebetween. Here, a pouch-shaped separator 4 is shown housing the negative electrode plates 2, but the shape of the separator is not particularly limited. In a cell chamber 14 located at one end of the battery case 12, a negative electrode shelf 6 that connects the ears 2 a of the plurality of negative electrode plates 2 in parallel is connected to a through-connector 8, and a positive electrode shelf 5 that connects the ears 3 a of the plurality of positive electrode plates 3 in parallel is connected to a positive electrode pole 7. The positive electrode pole 7 is connected to a positive electrode terminal 17 outside the lid 15. In the cell chamber 14 located at the other end of the battery case 12, a negative electrode pole 9 is connected to the negative electrode shelf 6, and a through-connector 8 is connected to the positive electrode shelf 5. The negative electrode pole 9 is connected to a negative electrode terminal 16 outside the lid 15. Each of the through-connectors 8 passes through a through-hole provided in the partition wall 13 and connects the electrode plate assemblies 11 of adjacent cell chambers 14 in series.

[0065] A lead-acid battery according to one aspect of the present invention is summarized below. (1) One aspect of the present invention is a lead-acid battery comprising: a negative electrode plate, a positive electrode plate, and an electrolyte; the negative electrode plate includes a negative electrode material containing a carbon material and an organic shrinkage preventer; the carbon material includes a first carbon material having a particle diameter of 32 μm or more and a second carbon material having a particle diameter of less than 32 μm; a ratio of powder resistance R2 of the second carbon material to powder resistance R1 of the first carbon material: R2 / R1 is 15 or more and 155 or less; the organic shrinkage preventer includes lignosulfonic acid or a salt thereof; and a content of the organic shrinkage preventer in the negative electrode material is 0.03% by mass or more and 0.8% by mass or less.

[0066] (2) In the above (1), it is preferable that the ratio of the specific surface area S2 of the second carbon material to the specific surface area S1 of the first carbon material, S2 / S1, is 20 or more.

[0067] (3) In the above (1) or (2), the ratio of the specific surface area S2 of the second carbon material to the specific surface area S1 of the first carbon material, S2 / S1, is preferably 240 or less.

[0068] (4) In any one of the above (1) to (3), the average aspect ratio of the first carbon material is preferably 1.5 or more.

[0069] (5) In any one of the above (1) to (4), the average aspect ratio of the first carbon material is preferably 30 or less.

[0070] (6) In any one of the above (1) to (5), the utilization rate of the negative electrode plate is preferably 40% or more. (7) In any one of the above (1) to (6), the utilization rate of the negative electrode plate is preferably 70% or less.

[0071] (8) In any one of (1) to (7) above, the content of the first carbon material in the negative electrode material is preferably 0.05% by mass or more. (9) In any one of (1) to (8) above, the content of the first carbon material in the negative electrode material is preferably 3.0% by mass or less. (10) In any one of (1) to (9) above, the content of the second carbon material in the negative electrode material is preferably 0.03% by mass or more. (11) In any one of (1) to (10) above, the content of the second carbon material in the negative electrode material is preferably 1.0% by mass or less. (12) In any one of (1) to 11) above, the first carbon material preferably includes at least graphite, and the second carbon material preferably includes at least carbon black.

[0072] EXAMPLES The present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited to the following examples.

[0073] Lead acid battery A1 (1) Preparation of negative electrode plate: Lead powder, water, dilute sulfuric acid, barium sulfate, a carbon material, and an organic shrinkage preventer are mixed to obtain a negative electrode paste. The negative electrode paste is filled into the mesh portion of an expanded lattice made of a Pb—Ca—Sn alloy, and the mixture is aged and dried to obtain an unformed negative electrode plate. Carbon black (average particle diameter D ５０ : 40 nm) and graphite (average particle diameter D ５０ The amount of negative electrode paste filled into the expanded grid is adjusted so that the utilization rate of the preformed negative electrode plate is 40%.

[0074] The organic shrinkage inhibitor is sodium lignin sulfonate. The amount of the organic shrinkage inhibitor is adjusted so that the content of the organic shrinkage inhibitor in 100% by mass of the negative electrode material after fully charged in a pre-formed state is 0.25% by mass. In addition, when preparing the negative electrode paste, the density of the negative electrode material after fully charged in a pre-formed state is adjusted to 4.0 g / cm. 3The amounts of water and dilute sulfuric acid added to the negative electrode paste are adjusted so that the density is equal to or less than 1000 kJ / cm2. The density of the negative electrode material is determined by fully charging the formed battery, disassembling it, and using the measurement sample recovered according to the procedure described above. The battery is fully charged according to the procedure described above. The density of the negative electrode material is measured using an automatic porosimeter (Autopore IV9505) manufactured by Shimadzu Corporation according to the method described above.

[0075] (2) Preparation of Positive Electrode Plate: Lead powder, water, and sulfuric acid are mixed to prepare a positive electrode paste. The positive electrode paste is filled into the mesh of an expanded lattice made of a Pb—Ca—Sn alloy, and the mixture is aged and dried to obtain an unformed positive electrode plate.

[0076] (3) Preparation of lead-acid battery: Unformed negative plates are housed in a pouch-shaped separator made of a polyethylene microporous membrane, and five unformed negative plates and four unformed positive plates are used per cell to form a plate assembly. The plate assembly is inserted into a polypropylene battery case, and electrolyte is poured in. Formation is performed inside the battery case to prepare a liquid lead-acid battery. The nominal voltage of the lead-acid battery is 12 V. The nominal capacity of this lead-acid battery is 28 Ah (5-hour rate).

[0077] For one of the produced lead-acid batteries, the content (c1 (mass %)) of the organic shrinkage-preventing agent contained in the negative electrode material (100 mass %) removed from the negative electrode plate is determined using the procedure described above. The content of the organic shrinkage-preventing agent determined in this manner will be somewhat different from the content (c2 (mass %)) of the organic shrinkage-preventing agent in the negative electrode material (100 mass %) prepared when producing the lead-acid battery. Therefore, the ratio R (=c1 / c2) of these contents c1 and c2 is determined in advance, and when preparing a negative electrode material to be used in the negative electrode plate of another lead-acid battery, the ratio R is used to adjust the content (c2 (mass %)) of the organic shrinkage-preventing agent in the prepared negative electrode material so that the content (c1 (mass %)) of the organic shrinkage-preventing agent in the negative electrode material becomes a predetermined value.

[0078] In this lead-acid battery, the content of the first carbon material is 1.0 mass %, and the content of the second carbon material is 0.3 mass %. These values ​​are determined as the content of each carbon material contained in the negative electrode material (100 mass %) when the negative electrode plate of the produced lead-acid battery is removed and the carbon material contained in the negative electrode material is separated into the first carbon material and the second carbon material using the procedure described above. The powder resistivity ratio R2 / R1 is 103. The average aspect ratio of the first carbon material is 7.3. The specific surface area ratio S2 / S1 is 112. The powder resistivity ratio R2 / R1, the average aspect ratio of the first carbon material, and the specific surface area ratio S2 / S1 are also determined using the procedure described above.

[0079] Lead-acid batteries A2 to A6 were fabricated in the same manner as lead-acid battery A1, except that the amount of the organic shrinkage preventer added was adjusted so that the content of the organic shrinkage preventer contained in 100% by mass of the pre-formed negative electrode material after full charge was the value shown in Table 2.

[0080] Lead-acid battery X1: Carbon black (average particle diameter D ５０ Only the second carbon material (e.g., 40 nm) was used, and the content of the second carbon material was 0.3 mass %. Except for the above, a lead-acid battery was fabricated in the same manner as the lead-acid battery A1.

[0081] Lead-acid battery X2: Carbon black (average particle diameter D ５０ Only the second carbon material (40 nm) was used, and the content of the second carbon material was 1.0 mass %. Except for the above, lead-acid batteries were fabricated in the same manner as lead-acid battery A1. Each lead-acid battery was evaluated as follows.

[0082] [Evaluation 1: PSOC Life Performance] Charge and discharge were performed at 25°C according to the pattern shown in Table 1. The number of cycles until the terminal voltage reached 1.2 V per single cell was used as an index of PSOC life performance. It was expressed as a ratio with the result for lead acid battery X1 set to 100.

[0083]

[0084] [Evaluation 2: Low-Temperature High-Rate Performance] Discharge at 6.25 CA at -15°C until the terminal voltage reaches 1 V per single cell, and determine the discharge time. This discharge time is used as an index of low-temperature high-rate performance. It is expressed as a ratio with the result for lead-acid battery X1 set to 100.

[0085] [Evaluation 3: Regenerative (Charging) Acceptance Performance] A fully charged lead-acid battery was discharged at 25°C and 0.2 CA for 10% of its nominal capacity, and then left at room temperature for 12 hours. It was then charged at a constant voltage of 2.42 V per cell, and the amount of electricity in the first 10 seconds was calculated and used as an index of regenerative acceptance performance. The results are expressed as a ratio, with the result for lead-acid battery X1 being set at 100. The evaluation results are shown in Table 2.

[0086]

[0087] When only the second carbon material is used, the low-temperature high-rate performance deteriorates when the content of the second carbon material is 1.0 mass%, compared to when the content of the second carbon material is 0.3 mass% (X1, X2). In contrast, when the first carbon material and the second carbon material are used in combination, excellent low-temperature HR performance and PSOC life performance can be obtained by setting the powder resistance ratio R2 / R1 within a specific range (A1, A3 to A5). Because the content of the organic shrinkage inhibitor can be as small as 0.8 mass% or less, excellent regenerative acceptance performance can be obtained (A1, A3 to A5). When the content of the organic shrinkage inhibitor exceeds 0.8 mass%, regenerative acceptance performance deteriorates (A6). When the content of the organic shrinkage inhibitor is less than 0.03 mass%, low-temperature high-rate performance deteriorates (A2).

[0088] Lead-acid batteries B1 to B7: The amount of organic shrinkage preventer added is adjusted so that the content of the organic shrinkage preventer in 100% by mass of the negative electrode material after fully charged with pre-formed chemicals is 0.01% by mass. The average particle size, specific surface area, and average aspect ratio of the first carbon material used are adjusted to obtain the powder resistance ratio R2 / R1 shown in Table 3. Other than the above, lead-acid batteries are fabricated and evaluated in the same manner as lead-acid battery A1.

[0089] <Lead-acid batteries C1 to C7> The amount of organic shrinkage preventer added is adjusted so that the content of the organic shrinkage preventer in 100% by mass of the negative electrode material after fully charged with pre-formed chemicals is 0.25% by mass. The powder resistance ratio R2 / R1 is set to the value shown in Table 3 by adjusting the average particle size, specific surface area, and average aspect ratio of the first carbon material used for each carbon material. Other than the above, lead-acid batteries are fabricated and evaluated in the same manner as lead-acid battery A1.

[0090] Lead-acid batteries D1 to D7: The amount of organic shrinkage preventer added is adjusted so that the content of the organic shrinkage preventer in 100% by mass of the negative electrode material after fully charged with pre-formed chemicals is 0.8% by mass. The powder resistance ratio R2 / R1 is set to the value shown in Table 3 by adjusting the average particle size, specific surface area, and average aspect ratio of the first carbon material used for each carbon material. Other than the above, lead-acid batteries are fabricated and evaluated in the same manner as lead-acid battery A1.

[0091] Lead-acid batteries E1 to E7: The amount of organic shrinkage preventer added is adjusted so that the content of the organic shrinkage preventer in 100% by mass of the negative electrode material after fully charged with pre-formed chemicals is 1.2% by mass. The average particle size, specific surface area, and average aspect ratio of the first carbon material used are adjusted to obtain the powder resistance ratio R2 / R1 shown in Table 3. Except for the above, lead-acid batteries are fabricated and evaluated in the same manner as lead-acid battery A1. The evaluation results are shown in Table 3. Note that lead-acid battery C5 in Table 3 is lead-acid battery A1.

[0092]

[0093] When the content of the organic shrinkage inhibitor is in the range of 0.03% by mass to 0.8% by mass and the powder resistance ratio R2 / R1 is in the range of 15 to 155, excellent PSOC life performance, low-temperature high-rate performance, and regeneration acceptance performance are obtained (C2 to C6, D2 to D6). When the content of the organic shrinkage inhibitor is 0.25% by mass, even higher PSOC life performance is obtained when the powder resistance ratio R2 / R1 is in the range of 80 to 110 (C4, C5). When the content of the organic shrinkage inhibitor is 0.8% by mass, even higher PSOC life performance is obtained when the powder resistance ratio R2 / R1 is in the range of 50 to 85 (D3, D4).

[0094] <Lead-acid batteries F1 to F7> By adjusting the specific surface area of ​​each carbon material used, the specific surface area ratio S2 / S1 calculated by the procedure described above is set to the value shown in Table 4. Except for the above, lead-acid batteries are fabricated and evaluated in the same manner as lead-acid battery A1. The evaluation results are shown in Table 4. Note that by adjusting the specific surface area of ​​each carbon material used, the powder resistance ratio R2 / R1 varies within a range of 83 or more and 103 or less. The evaluation results are also shown in Table 4. Note that lead-acid battery F5 in Table 4 is lead-acid battery A1.

[0095]

[0096] When the specific surface area ratio S2 / S1 is in the range of 20 to 240, a good balance of excellent PSOC life performance, low-temperature high-rate performance, and charge acceptance performance is obtained (F2 to F6). When the specific surface area ratio S2 / S1 is in the range of 100 to 240, the low-temperature high-rate performance is maintained, while the PSOC life performance and charge acceptance performance are further improved (F5, F6).

[0097] <Lead-acid batteries G1 to G7> The aspect ratio of the first carbon material used is adjusted to set the average aspect ratio of the first carbon material obtained by the above-described procedure to the value shown in Table 6. Except for the above, lead-acid batteries are fabricated and evaluated in the same manner as lead-acid battery A1.

[0098] The evaluation results are shown in Table 5. By adjusting the aspect ratio of the first carbon material used, the powder resistance ratio R2 / R1 changes in the range of 83 or more and 103 or less, and the specific surface area ratio S2 / S1 changes in the range of 40 or more and 112 or less. Furthermore, the lead-acid battery G3 in Table 5 is the lead-acid battery A1.

[0099]

[0100] When the average aspect ratio of the first carbon material is in the range of 1.5 or more and 30 or less, the PSOC life performance is further improved while maintaining high low-temperature high-rate performance (G2 to G5).

[0101] <<Lead-acid battery H1>> A lead-acid battery was produced and evaluated in the same manner as lead-acid battery A1, except that in the production of the negative electrode plate, the amount of negative electrode paste filled into the expanded grid was adjusted so that the utilization rate of the pre-formed negative electrode plate was 65%.

[0102] <Lead-acid batteries H2 to H7> By adjusting the average particle size, specific surface area, and average aspect ratio of each carbon material used, the powder resistance ratio R2 / R1 is set to the value shown in Table 6. Other than the above, lead-acid batteries are fabricated and evaluated in the same manner as lead-acid battery H1.

[0103] <<Lead-acid battery X3>> Carbon black (average particle diameter D ５０ Only lead-acid battery H1 (40 nm) was used, and the content of the second carbon material was 0.3 mass %. Except for the above, a lead-acid battery was fabricated and evaluated in the same manner as lead-acid battery H1. The evaluation results are shown in Table 6. The values ​​of PSOC life performance, low-temperature high-rate performance, and regeneration acceptance performance in Table 6 are each expressed as a ratio when the result of lead-acid battery X3 is set to 100.

[0104]

[0105] Even when the negative plate utilization rate is 65%, by using two types of carbon materials with different particle sizes and powder resistivity ratios within a specific range together with a small amount of an organic shrinkage inhibitor within a specific range, PSOC life performance can be improved while maintaining low-temperature high-rate performance and regenerative acceptance performance (H1, H3 to H6). When the negative plate utilization rate is high at 50% or higher, the low-temperature high-rate performance and PSOC life performance are more significantly improved when the powder resistivity ratio R2 / R1 is in the range of 100 or higher. The improvement is greater in lead-acid batteries H1 and H6 (Table 6) with a negative plate utilization rate of 65% than in lead-acid batteries C5 and C6 (Table 3) with a negative plate utilization rate of 40%.

[0106] A lead-acid battery according to one aspect of the present invention can be applied to valve-regulated and flooded lead-acid batteries, and can be suitably used as a power source for starting automobiles or motorcycles, or as an industrial power storage device used for storing natural energy, etc.

[0107] REFERENCE SIGNS LIST 1 Lead-acid battery 2 Negative electrode plate 2a Negative electrode plate lug 3 Positive electrode plate 4 Separator 5 Positive electrode shelf 6 Negative electrode shelf 7 Positive electrode column 8 Penetration connector 9 Negative electrode column 11 Electrode plate group 12 Battery case 13 Partition wall 14 Cell chamber 15 Lid 16 Negative electrode terminal 17 Positive electrode terminal 18 Vent plug

Claims

DEPCT631. A lead-acid battery which is a lead-acid battery in which such lead-acid battery has a negative plate, a positive plate and an electrolyte solution. Such negative plate consists of a negative electrode material composed of carbon material and an organic expander. Such carbon material consists of carbon I material with a particle size greater than or equal to 32 micrometers and carbon II material with a particle size smaller than 32 micrometers. The ratio between the powder resistance R2 of such carbon I material and the powder resistance R1 of such carbon I material: R2 / R1 is greater than or equal to 15, less than or equal to 155. Such organic expander consists of lignin, sulfonic acid or salts of such, the amount of such organic expander present in such negative electrode material is greater than or equal to 0.03% by mass, less than or equal to 0.8% by mass.

2. A lead-acid battery specified in claim 1 in which the ratio between the specific surface area S2 of such carbon I material and the specific surface area S1 of such carbon I material: S2 / S1 is greater than or equal to 20. 3.

1. Lead-acid batteries specified in Relief 1 or 2 where the ratio between the specific surface area S2 of such carbon 2 material and the specific surface area S1 of such carbon 1 material: S2 / S1 is less than or equal to 240.

4. Lead-acid batteries specified in any of Reliefs 1-3 where the average surface area ratio of such carbon 1 material is greater than or equal to 1.

55. Lead-acid batteries specified in Reliefs 1-4 where the average surface area ratio of such carbon 1 material is less than or equal to 30.

6. Lead-acid batteries specified in Reliefs 1-5 where the utilization rate of such negative plate is greater than or equal to 40%.

7. Lead-acid batteries specified in Reliefs 1-6 where the utilization rate of such negative plate is less than or equal to 70%.

8. Lead-acid batteries specified in Reliefs 1-7 where the amount of such carbon 1 material present in such negative electrode material is greater than or equal to 0.05% by mass. 9.

10. Any lead-acid battery specified in Reliefs 1-8 where the amount of carbon I material present in the anion electrode material is less than or equal to 3.0% by mass.

11. Any lead-acid battery specified in Reliefs 1-9 where the amount of carbon II material present in the anion electrode material is greater than or equal to 0.03% by mass.

12. Any lead-acid battery specified in Reliefs 1-10 where the amount of carbon II material present in the anion electrode material is less than or equal to 1.0% by mass.

13. Any lead-acid battery specified in Reliefs 1-11 where the carbon I material contains at least graphite and the carbon II material contains at least carbon black.