WO2018199125A1

WO2018199125A1 - Lead acid battery

Info

Publication number: WO2018199125A1
Application number: PCT/JP2018/016697
Authority: WO
Inventors: 剛志國澤; 朋子松村
Original assignee: 株式会社Ｇｓユアサ
Priority date: 2017-04-28
Filing date: 2018-04-25
Publication date: 2018-11-01
Also published as: CN110546793B; CN110546793A; JP7099451B2; JPWO2018199125A1

Abstract

[Solution] A lead acid battery provided with a negative pole plate and a positive pole plate. The negative pole plate includes a negative pole electrode material containing a carbon material and an oil. The carbon material includes a first carbon material having a particle size of not less than 32 μm and a second carbon material having a particle size of less than 32 μm. The ratio R2/R1 of a powder resistance R2 of the second carbon material to a powder resistance R1 of the first carbon material is not less than 15 and not more than 155. The negative pole electrode material has an oil content of not less than 0.05 mass% and not more than 1 mass%.

Description

Lead acid battery

The present invention relates to a lead storage battery.

Lead acid batteries are used for various purposes in addition to automotive and industrial use. The lead acid battery includes a negative electrode plate including a negative electrode material. The lead acid battery manufacturing process includes, for example, a process of forming an unformed negative electrode plate, then washing with water and drying to obtain an already formed (charged) negative electrode plate (negative electrode active material). However, the negative electrode active material contained in the negative electrode material deteriorates due to oxidation during the period from the preparation of the formed negative electrode plate to the assembly of the lead storage battery using the negative electrode plate and the injection of the electrolyte into the lead storage battery. To do. In particular, the ready-made lead-acid storage battery in which the formed positive and negative electrode plates are stored in a dry state in the battery case during battery storage, and the electrolyte is injected when the battery is used, the period during which the negative electrode plate is exposed to the atmosphere. Since it is long, the oxidative deterioration of the negative electrode active material tends to proceed. Due to the oxidative deterioration of the negative electrode active material, the initial discharge performance of the lead-acid battery decreases. Therefore, oil is included in the negative electrode material in order to prevent oxidation of the negative electrode active material (Patent Document 1).

JP-A-11-354123

Lead-acid batteries are sometimes used in an undercharged state called partially charged state (PSOC). For example, lead-acid batteries are used as industrial power storage devices such as start-up power sources for automobiles or motorcycles, such as charge control vehicles and idling stop (IS) vehicles, or storage of natural energy such as sunlight and wind power. In many cases, it is used in the PSOC state. Therefore, the lead storage battery is required to have high life performance in the PSOC cycle.

In order to improve such life performance, it is effective to increase the amount of carbon black added to the negative electrode material. However, since oil is adsorbed by carbon black, if a large amount of carbon black is added, the negative electrode active material contained in the negative electrode material is likely to be oxidized and deteriorated, and the initial discharge performance is lowered. In order to suppress the deterioration of the initial discharge performance, it is conceivable to increase the amount of oil. However, when a large amount of oil is added, the charge acceptance performance decreases.

Thus, it is difficult to improve the life performance in the PSOC cycle without impairing the initial discharge performance and the charge acceptance performance.

One aspect of the present invention is a lead acid battery, wherein the lead acid battery includes a negative electrode plate and a positive electrode plate, and the negative electrode plate includes a negative electrode material containing a carbon material and oil, and 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 powder of the second carbon material against the powder resistance R1 of the first carbon material Ratio of body resistance R2: R2 / R1 is 15 or more and 155 or less, and the content of the oil in the negative electrode material is 0.05% by mass or more and 1% by mass or less.

According to the present invention, in a lead-acid battery, life performance in the PSOC cycle can be enhanced without impairing initial discharge performance and charge acceptance performance.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view with a part cut away showing an external appearance and an internal structure of a lead storage battery according to an embodiment of the invention.

One aspect of the present invention is a lead acid battery, the lead acid battery includes a negative electrode plate and a positive electrode plate, and the negative electrode plate includes a negative electrode material containing a carbon material and oil. The negative electrode 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 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 content of oil in the negative electrode material is 0.05% by mass or more and 1% by mass or less.

By using two types of carbon materials having different particle diameters with a powder resistance ratio in a specific range together with a small amount of oil, the life performance in the PSOC cycle (hereinafter also referred to as PSOC life performance) can be enhanced. . By using a combination of two types of carbon materials having a powder resistance ratio in a specific range and different particle diameters, even if the amount of oil added is 0.05% to 1% by mass, Oxidation is sufficiently suppressed, and high initial discharge performance is obtained. Since the amount of oil added is as small as 1% by mass or less, a decrease in charge acceptance performance due to an increase in the amount of oil added is avoided.

Carbon materials having various powder resistances are known. It is known that the powder resistance of a powder material varies depending on the shape of the particle, the particle diameter, the internal structure of the particle, and / or the crystallinity of the particle. In the conventional technical common sense, the powder resistance of the carbon material is not directly related to the resistance of the negative electrode plate, and is not considered to affect the PSOC life performance and the initial discharge performance.

On the other hand, according to the above aspect of the present invention, by using a combination of the first carbon material and the second carbon material having different particle diameters, the powder resistance ratio is in a specific range, together with a small amount of oil, Discharge performance is improved. This is considered to be due to the fact that the adsorption of oil to the second carbon material is suppressed and the effect of the oil is sufficiently exhibited even with a small amount of oil.

In the above aspect of the present invention, by controlling the powder resistance ratio R2 / R1 between the first carbon material and the second carbon material contained in the negative electrode plate in the range of 15 to 155, high PSOC life performance can be obtained. it can. This is presumably due to the following reasons. First, by controlling the powder resistance ratio R2 / R1 within the above range, a conductive network is easily formed in the negative electrode material. Furthermore, by controlling the oil content to 0.05 mass% or more and 1 mass% or less, oxidation of the negative electrode active material is suppressed without adversely affecting the formation of the conductive network. Since the oxidation of the negative electrode active material is suppressed, the function of the conductive network is sufficiently exhibited. Further, since the amount of oil is small, the formation of the conductive network is not adversely affected, and the formed conductive network is easily maintained even after the PSOC cycle.

(oil)
Examples of the oil include paraffinic oil, naphthenic oil, olefinic oil, aromatic oil, and silicone oil. Commercial oils contain various additives such as antioxidants. As the various additives, those contained in appropriate amounts within the range usually used can be used.

The content of oil in the negative electrode material is 0.05% by mass or more and 1% by mass or less. In this case, excellent PSOC life performance, initial discharge performance, and charge acceptance performance can be obtained. When the content of oil in the negative electrode material is less than 0.05% by mass, the initial discharge performance is degraded. When the content of oil in the negative electrode material is more than 1% by mass, the charge acceptance performance is degraded. The oil content in the negative electrode material is preferably 0.05% by mass or more and 0.5% by mass or less. In this case, PSOC life performance and charge acceptance performance are further improved.

In addition, content of the oil in said negative electrode material accounts to the negative electrode material contained in the already formed negative electrode plate (before inject | pouring electrolyte solution into a lead storage battery) after passing through the process of chemical conversion, water washing, and drying. It is the mass ratio of oil. In the case of a ready-to-use lead storage battery, this is the oil content in the negative electrode material during battery storage.

Hereinafter, the measurement of the oil content in the negative electrode material will be described.
(A) Measurement of oil content The negative electrode material is separated from the already formed negative electrode plate after the steps of chemical conversion, water washing and drying. Or the lead acid battery before inject | pouring electrolyte solution is decomposed | disassembled, an already-formed negative electrode plate is taken out, and negative electrode material is isolate | separated from the said negative electrode plate. The negative electrode material is pulverized to obtain a sample powder having a mass Ma. A sample solution is obtained by adding normal hexane to the sample powder. The sample solution is heated at 65 ° C. for 1 hour. Thereafter, the sample solution is filtered to obtain a filtrate. The filtrate is heated at 65 ° C. for 1 hour to give a residue. The residue is weighed, and this is the oil mass Mb. Using the above Ma and Mb, the oil content in the negative electrode material is obtained from the following formula.
Oil content (%) in negative electrode material = (mass Mb / mass Ma) × 100

Moreover, even if it is a lead storage battery (other than an immediate use lead storage battery) in which electrolyte solution was inject | poured, when it is an unused lead storage battery, content of the oil in negative electrode material is calculated | required with the following procedures.
The negative electrode plate is taken out from the lead-acid battery into which the electrolytic solution has been injected, and the sulfuric acid content is removed by washing with water, followed by vacuum drying (drying under a pressure lower than atmospheric pressure). Thereafter, the negative electrode material is separated from the negative electrode plate, and the oil content in the negative electrode material is determined by the method described above.

In the above unused batteries, the oil in the negative electrode plate hardly flows into the electrolyte. However, when the battery is left for a long period of time, the state of the battery (negative electrode plate) may change. Therefore, the unused battery is a battery immediately after manufacture (within one month from manufacture).

(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. A 1st carbon material and a 2nd carbon material are isolate | separated and distinguished in the procedure mentioned later.

Examples of each carbon material include carbon black, graphite, hard carbon, and soft carbon. Examples of carbon black include acetylene black, ketjen black, furnace black, and lamp black. As the graphite, any carbon material including a graphite type crystal structure may be used, and any of artificial graphite and natural graphite may be used.

The intensity of a peak appearing in 1300 cm ^-1 or 1350 cm ^-1 or less in the range of the Raman spectrum (D band) and 1550 cm ^-1 or 1600 cm ^-1 peak appearing in the range (G band) of the first carbon material Graphite having a ratio I _D / I _G of 0 or more and 0.9 or less is defined as graphite.

The first carbon material and the second carbon material have a ratio of the powder resistance R2 of the second carbon material to the powder resistance R1 of the first carbon material: R2 / R1 of 15 to 155. The type may be selected or the particle diameter, specific surface area, and / or aspect ratio of each carbon material may be adjusted.

The first carbon material is preferably at least one selected from the group consisting of graphite, hard carbon, and soft carbon, for example. In particular, the first carbon material preferably contains at least graphite. The second carbon material preferably contains at least carbon black. When these carbon materials are used, it is easy to adjust the powder resistance ratio R2 / R1.

When the powder resistance ratio R2 / R1 is 15 or more and 155 or less, excellent PSOC life performance, initial discharge performance, and charge acceptance performance can be obtained. The powder resistance ratio R2 / R1 is preferably 55 or more and 155 or less, more preferably 55 or more and 130 or less. In this case, excellent PSOC life performance, initial performance, and charge acceptance performance can be obtained with a better balance.

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 550 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, initial discharge performance, and charge acceptance performance can be obtained with a good balance. When S2 / S1 is 20 or more, the adsorption of oil is further suppressed when the specific surface area of each carbon material is in an appropriate range. As a result, the initial discharge performance is further improved. When S2 / S1 is 240 or less, the lead sulfate reduction reaction easily proceeds, so that the charge acceptance performance is further improved while ensuring high PSOC life performance.

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, and more preferably 1.5 or more. Moreover, Preferably it is 100 or less, More preferably, it is 35 or less, More preferably, it is 30 or less. These upper and lower limits can be arbitrarily combined.
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 enhanced while maintaining good initial discharge performance and charge acceptance performance. This is considered to be because when the average aspect ratio is in such a range, a conductive network is easily formed in the negative electrode material, and the formed conductive network is easily maintained.

Further, when the average aspect ratio of the first carbon material is 1.5 or more, since the outflow of the carbon material to the electrolytic solution due to repeated charge and discharge is suppressed, the effect of improving the PSOC life performance is further increased. be able to. In addition, when the average aspect ratio of the first carbon material is 30 or less, it becomes easy to ensure the adhesion between the active material particles, so that the generation of cracks in the negative electrode plate is suppressed, and the deterioration of the life performance can be suppressed.

The average aspect ratio of the first carbon material is more preferably 5 or more and 30 or less, and further preferably 10 or more and 30 or less, from the viewpoint that excellent PSOC life performance, initial discharge performance, and charge acceptance performance can be obtained in a balanced manner.

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 it is 0.1 mass% or more, More preferably, it is 0.4 mass% or more. Moreover, Preferably it is 2.0 mass% or less, More preferably, it is 2.0 mass% or less. These upper and lower limits can be combined arbitrarily. When the content of the first carbon material in the negative electrode material is 0.05% by mass or more, the effect of improving the PSOC life performance can be further enhanced. When the content of the first carbon material in the negative electrode material is 3.0% by mass or less, it becomes easy to ensure the adhesion between the active material particles, so that the generation of cracks in the negative electrode plate is suppressed, and the high PSOC lifetime is achieved. Ensuring performance is even easier.

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 it is 0.05 mass% or more. Moreover, it is 1.0 mass% or less preferably, More preferably, it is 0.5 mass% or less. These upper and lower limits can be combined arbitrarily. 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 initial discharge performance can be further improved by further suppressing the adsorption of oil.
The content of each carbon material in the negative electrode material is obtained by the procedure (B-1) described later.

A method for determining or analyzing the physical properties of the carbon material will be described below.
(B) Analysis of carbon material (B-1) Separation of carbon material In the case of a lead storage battery equipped with a pre-formed positive and negative electrode plate before injecting the electrolyte, the battery is disassembled and dried Take out the negative electrode plate. In addition, in the case of a lead-acid battery that is provided with a pre-formed positive and negative electrode plate and into which an electrolytic solution has been injected, The chemical conversion negative electrode plate is taken out, and the sulfuric acid is removed by washing with water, followed by vacuum drying (drying under a pressure lower than atmospheric pressure). Next, the negative electrode material is collected from the dried negative electrode plate and pulverized. To 5 g of the crushed sample, 30 mL of a 60% strength by weight aqueous nitric acid solution is added and heated at 70 ° C. Further, 10 g of disodium ethylenediaminetetraacetate, 30 mL of 28 mass% ammonia water, and 100 mL of water are added, and heating is continued to dissolve soluble components. The sample thus pretreated is collected by filtration. The collected sample is passed through a sieve having an opening of 500 μm, components having a large size such as a reinforcing material are removed, and the component that has passed through the sieve is collected as a carbon material.

When the collected carbon material is sieved by a wet method using a sieve having an opening of 32 μm, the first carbon material remains on the sieve without passing through the sieve eyes, and passes through the sieve eyes. This is the second carbon material. That is, the particle diameter of each carbon material is based on the size of the sieve opening. For wet sieving, JIS Z8815: 1994 can be referred to.

Specifically, a carbon material is placed on a sieve having an opening of 32 μm, and screened by gently shaking the sieve for 5 minutes while sprinkling ion-exchanged water. The first carbon material remaining on the sieve is collected from the sieve by pouring ion-exchanged water, and separated from the ion-exchanged water by filtration. The 2nd carbon material which passed the sieve is collect | recovered by filtration using the membrane filter (aperture 0.1 micrometer) made from nitrocellulose. The recovered first carbon material and second carbon material are each dried at a temperature of 110 ° C. for 2 hours. As the sieve having a mesh opening of 32 μm, a sieve having a sieve mesh having a nominal mesh opening of 32 μm as defined in JIS Z 8801-1: 2006 is used.

In addition, content of each carbon material in a negative electrode material measures the mass of each carbon material isolate | separated in said procedure, and calculates the ratio (mass%) which occupies for 5 g of pulverized samples of this mass. Ask.

(B-2) Powder Resistance of Carbon Material The powder resistance R1 of the first carbon material and the powder resistance R2 of the second carbon material are the first carbon material and the second carbon material separated in the procedure of (B-1). For each of the two carbon materials, 0.5 g of the sample was put into a powder resistance measurement system (manufactured by Mitsubishi Chemical Analytech Co., Ltd., MCP-PD51 type), and under a pressure of 3.18 MPa, JIS K 7194: 1994 This is a value measured by a four-probe method using a compliant low resistance meter (Loresta-GX MCP-T700, manufactured by Mitsubishi Chemical Analytech Co., Ltd.).

(B-3) Specific surface area of carbon material 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 the 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). Each carbon material is pretreated by heating for 1 hour at a temperature of 150 ° C. in a nitrogen flow. Using the pretreated carbon material, the BET specific surface area of each carbon material is determined under the following conditions using the following apparatus.
Measuring device: TriStar3000 manufactured by Micromeritics
Adsorption gas: Nitrogen gas with a purity of 99.99% or more Adsorption temperature: Liquid nitrogen boiling point temperature (77K)
BET specific surface area calculation method: Conforms to 7.2 of JIS Z 8830: 2013

(B-4) Average aspect ratio of first carbon material The first carbon material separated by the procedure of (B-1) is observed with an optical microscope or an electron microscope, and 10 or more arbitrary particles are selected. Take a magnified photo of it. Next, the photograph of each particle is image-processed to determine the maximum diameter d1 of the particle and the maximum diameter d2 in the direction orthogonal to the maximum diameter d1, and the aspect ratio of each particle is determined by dividing d1 by d2. Ask. The average aspect ratio is calculated by averaging the obtained aspect ratios.

Hereinafter, although the lead storage battery which concerns on embodiment of this invention is demonstrated for every main component requirement, this invention is not limited to the following embodiment.
(Negative electrode plate)
The negative electrode plate of the lead storage battery includes a negative electrode material. The negative electrode plate can usually be composed of a negative electrode grid (negative electrode current collector) and a negative electrode material. The negative electrode material is obtained by removing the negative electrode current collector from the negative electrode plate.
Note that members such as a mat and pasting paper may be attached to the negative electrode plate. When the negative electrode plate includes such a member (sticking member), the negative electrode material is obtained by removing the negative electrode current collector and the sticking member. However, the thickness of the electrode plate includes the mat. When the mat is attached to the separator, the thickness of the mat is included in the thickness of the separator.

The negative electrode material preferably contains a negative electrode active material (lead or lead sulfate) that develops capacity by oxidation-reduction reaction. The negative electrode active material in the charged state is spongy lead, but the unformed negative electrode plate is usually produced using lead powder. The negative electrode material includes the above-described carbon material and oil. The negative electrode material may further contain an organic shrinking agent, barium sulfate, and the like, and may contain other additives as necessary. Lignin (lignin sulfonic acid or a salt thereof) or the like is used as the organic shrinking agent.

The content of the organic shrinking agent contained in the negative electrode material is, for example, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and further preferably 0.05% by mass or more. On the other hand, 1.0 mass% or less is preferable, 0.8 mass% or less is more preferable, and 0.5 mass% or less is still more preferable. These lower limit values and upper limit values can be arbitrarily combined. Here, the content of the organic shrinking agent contained in the negative electrode material is a content in the negative electrode material collected by a method described later from a lead-acid battery in a fully formed state.

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, or 1.0% by mass or more, It may be 1.3% by mass or more. On the other hand, 3.0 mass% or less is preferable, 2.5 mass% or less is more preferable, and 2 mass% or less is still more preferable. These lower limit values and upper limit values can be arbitrarily combined.

Hereinafter, the organic shrinkage agent contained in the negative electrode material and the determination method of barium sulfate will be described. Prior to quantitative analysis, the formed lead-acid battery is fully charged and then disassembled to obtain the negative electrode plate to be analyzed. The obtained negative electrode plate is washed with water and dried to remove the electrolyte in the negative electrode plate. Next, the negative electrode material is separated from the negative electrode plate, and an unground initial sample is obtained.

[Organic shrinkage agent]
The unpulverized initial sample is pulverized, and the pulverized initial sample is immersed in a 1 mol / L NaOH aqueous solution to extract the organic antishrink agent. Insoluble components are removed by filtration from the aqueous NaOH solution containing the extracted organic shrinking agent. The obtained filtrate (hereinafter also referred to as “analyte filtrate”) is desalted, concentrated and dried to obtain an organic shrunk agent powder (hereinafter also referred to as “analyte powder”). Desalting may be performed by placing the filtrate in a dialysis tube and immersing it in distilled water.

Infrared spectrum of the analysis target powder, UV-visible absorption spectrum of the solution obtained by dissolving the analysis target powder in distilled water, etc., NMR spectrum of the solution obtained by dissolving the analysis target powder in a solvent such as heavy water, By obtaining information from pyrolysis GC-MS or the like that can obtain information on the individual compounds constituting the organic compound, the organic shrinking agent is specified.

Measure the UV-visible absorption spectrum of the above filtrate. The content of the organic shrinkage agent in the negative electrode material is quantified using the spectral intensity and a calibration curve prepared in advance. If the structural formula of the organic pre-shrinking agent to be analyzed cannot be strictly specified and the same organic pre-shrinking agent calibration curve cannot be used, the UV-visible absorption spectrum, infrared spectroscopic spectrum similar to the organic pre-shrinking agent to be analyzed, A calibration curve is created using an available organic shrinkage agent, such as an NMR spectrum.

[Barium sulfate]
The unpulverized initial sample is pulverized, and 50 ml of (1 + 2) nitric acid is added to 10 g of the pulverized initial sample and heated for about 20 minutes to dissolve the lead component as lead nitrate. Next, the solution containing lead nitrate is filtered to separate carbonaceous material, barium sulfate and other solid contents.

After the obtained solid content is dispersed in water to obtain a dispersion, components other than the carbonaceous material and barium sulfate (for example, reinforcing material) are removed from the dispersion using a sieve. Next, the dispersion liquid 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 sample separated by filtration is a mixed sample of a 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 mixed sample and the membrane filter after drying. Thereafter, the mixed sample after drying is put into a crucible together with a membrane filter, and ashed at 700 ° C. or higher. The remaining residue is barium oxide. The mass (B) of barium sulfate is determined by converting the mass of barium oxide into the mass of barium sulfate.

The negative electrode current collector may be formed by casting lead (Pb) or a lead alloy, or may be formed by processing a lead or lead alloy sheet. Examples of the processing method include an expanding process and a punching process.

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 alloy may further contain at least one selected from the group consisting of Ba, Ag, Al, Bi, As, Se, Cu and the like as an additive element.

The negative electrode plate can be formed by filling a negative electrode paste into a negative electrode current collector, aging and drying to produce an unformed negative electrode plate, and then forming an unformed negative electrode plate. Sponge-like lead is generated by chemical conversion. The negative electrode paste is prepared by adding water and sulfuric acid to a lead powder, an organic shrinking agent, and various additives as necessary, and kneading them. When aging, it is preferable to age the unformed negative electrode plate at a temperature higher than room temperature and high humidity.

(Positive electrode plate)
There are a paste type and a clad type in the positive electrode plate of the lead storage battery.
The paste type positive electrode plate includes 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.

The clad positive electrode plate includes a plurality of porous tubes, a core metal inserted into each tube, a current collector for connecting the metal cores, and a positive electrode material filled in the tube in which the metal core is inserted And a joint for connecting a plurality of tubes. The metal core and the current collector that connects the metal cores are collectively referred to as a positive electrode current collector.

As the lead alloy used for the positive electrode current collector, a Pb—Ca alloy and a Pb—Ca—Sn alloy are preferable in terms of corrosion resistance and mechanical strength. The positive electrode current collector may have lead alloy layers having different compositions, and a plurality of alloy layers may be provided. For the core metal, a Pb—Ca alloy, a Pb—Sb alloy, or the like is used.

The positive electrode material includes a positive electrode active material (lead dioxide or lead sulfate) that develops capacity by oxidation-reduction reaction. The positive electrode material may contain other additives as necessary.

An unformed paste-type positive electrode plate is obtained by filling a positive electrode current collector with a positive electrode paste, aging and drying in the same manner as in the case of a negative electrode plate. Thereafter, an unformed positive electrode plate is formed. The positive electrode paste is prepared by kneading lead powder, additives, water, and sulfuric acid. When aging, it is preferable to age the unformed positive electrode plate at a temperature higher than room temperature and high humidity.

The clad type positive electrode plate is formed by filling a tube in which a metal core is inserted with lead powder or slurry-like lead powder and joining a plurality of tubes in a row.

(Separator)
Usually, a separator is disposed between the negative electrode plate and the positive electrode plate. A nonwoven fabric, a microporous film, etc. are used for a separator. The thickness and number of separators interposed between the negative electrode plate and the positive electrode plate may be selected according to the distance between the electrodes.
The nonwoven fabric is a mat in which fibers are entangled without being woven, and mainly includes fibers. For example, 60% by mass or more of the separator is formed of fibers. As the fiber, glass fiber, polymer fiber (polyolefin fiber, acrylic fiber, polyester fiber such as polyethylene terephthalate fiber), pulp fiber, or the like can be used. Among these, glass fiber is preferable. The nonwoven fabric may contain components other than fibers, such as acid-resistant inorganic powder, a polymer as a binder, and the like.

On the other hand, the microporous membrane is a porous sheet mainly composed of components other than the fiber component. For example, after a composition containing a pore forming agent (polymer powder and / or oil) is extruded into a sheet shape, It is obtained by removing the agent to form pores. The microporous membrane is preferably composed of a material having acid resistance, and is preferably composed mainly of a polymer component. As the polymer component, polyolefins such as polyethylene and polypropylene are preferable.

The separator may be composed of, for example, only a non-woven fabric or a microporous film. In addition, the separator may be a laminate of a nonwoven fabric and a microporous film, a product obtained by bonding different types or the same types of materials, or a type obtained by engaging unevenness in different types or the same types of materials, if necessary.

(Electrolyte)
The electrolytic solution is an aqueous solution containing sulfuric acid, and may be gelled as necessary. The specific gravity at 20 ° C. of the electrolyte in a fully charged lead storage battery after formation is, for example, 1.10 to 1.35 g / cm ³ , and preferably 1.20 to 1.35 g / cm ³ .

Generally, after forming an electrode plate group using unformed positive and negative electrode plates and storing them in a battery case, an electrolyte is injected into the battery case to form an unformed positive and negative electrode plate. On the other hand, in the case of a ready-to-use lead-acid battery, an electrode plate group is configured using positive and negative electrodes formed in advance, and stored in a battery case. Since the positive and negative electrode plates already formed in the battery case are stored in a dry state when the battery is stored, the battery is used by injecting an electrolyte into the battery case. The oil contained in the negative electrode material suppresses oxidative degradation of the negative electrode active material that occurs during the storage period until the electrolyte is injected.

In FIG. 1, the external appearance of an example of the lead acid battery which concerns on embodiment of this invention is shown.
The lead storage battery 1 includes a battery case 12 that houses an electrode plate group 11 and an electrolytic solution (not shown). The battery case 12 is partitioned into a plurality of cell chambers 14 by partition walls 13. Each cell chamber 14 accommodates one electrode group 11. The opening of the battery case 12 is sealed with a lid 15 having a negative electrode terminal 16 and a positive electrode terminal 17. The lid 15 is provided with a liquid plug 18 for each cell chamber. At the time of refilling, the refilling liquid is replenished by removing the liquid stopper 18. The liquid spout 18 may have a function of discharging gas generated in the cell chamber 14 to the outside of the battery.

The electrode plate group 11 is configured by laminating a plurality of negative plates 2 and positive plates 3 with a separator 4 interposed therebetween. Here, although the bag-shaped separator 4 which accommodates the negative electrode plate 2 is shown, the form of a separator is not specifically limited. In the cell chamber 14 located at one end of the battery case 12, the negative electrode shelf 6 that connects the ears 2 a of the plurality of negative electrode plates 2 in parallel is connected to the through connection body 8, and the ears of the plurality of positive electrode plates 3. A positive electrode shelf 5 that connects 3 a in parallel is connected to the positive pole 7. The positive pole 7 is connected to a positive terminal 17 outside the lid 15. In the cell chamber 14 located at the other end of the battery case 12, the negative electrode column 9 is connected to the negative electrode shelf 6, and the through connector 8 is connected to the positive electrode shelf 5. The negative pole 9 is connected to the negative terminal 16 outside the lid 15. Each through-connector 8 passes through a through-hole provided in the partition wall 13 and connects the electrode plate groups 11 of the adjacent cell chambers 14 in series.

The negative electrode plate for a lead storage battery according to one aspect of the present invention will be described collectively below.
(1) One aspect of the present invention is a lead acid battery,
The lead storage battery includes a negative electrode plate and a positive electrode plate,
The negative electrode plate includes a negative electrode material containing a carbon material and oil,
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 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 content of the oil in the negative electrode material is a lead storage battery that is 0.05% by mass or more and 1% by mass or less.

(2) In the above (1), 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 20 or more.

(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.

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

(6) In any one of the above (1) to (5), the content of the first carbon material in the negative electrode material is preferably 0.05% by mass or more.
(7) In any one of the above (1) to (6), the content of the first carbon material in the negative electrode material is preferably 3.0% by mass or less.
(8) In any one of the above (1) to (7), the content of the second carbon material in the negative electrode material is preferably 0.03% by mass or more.
(9) In any one of the above (1) to (8), the content of the second carbon material in the negative electrode material is preferably 1.0% by mass or less.
(10) In any one of the above (1) to (9), it is preferable that the first carbon material includes at least graphite, and the second carbon material includes at least carbon black.

Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.

<< Lead storage battery A1 >>
(1) Preparation of negative electrode plate Lead powder, water, dilute sulfuric acid, barium sulfate, organic anti-shrink agent, carbon material, and oil are mixed to obtain a negative electrode paste. The negative electrode paste is filled in a network portion of an expanded lattice made of a Pb—Ca—Sn alloy, and aged and dried to obtain an unformed negative electrode plate. As the carbon material, carbon black (average particle diameter D ₅₀ : 40 nm) and graphite (average particle diameter D ₅₀ : 110 μm) are used. An unformed negative electrode plate is formed, then washed with water and dried to obtain an already formed negative electrode plate.

パラフィン Use paraffin oil as the oil. The oil is blended in the negative electrode paste by adjusting the addition amount so that the content of oil contained in 100% by mass of the negative electrode material of the formed negative electrode plate is 0.5% by mass. The addition amount is adjusted in consideration of a small amount of oil flowing out from the negative electrode plate in the chemical conversion and subsequent water washing steps.

(2) Preparation of positive electrode plate A positive electrode paste is prepared by kneading lead powder, water, and sulfuric acid. The positive electrode paste is filled in a network portion of an expanded lattice made of a Pb—Ca—Sn alloy, and aged and dried to obtain an unformed positive electrode plate. An unformed positive electrode plate is formed, and then washed and dried to obtain an already formed positive electrode plate.

(3) Production of lead-acid battery The pre-formed negative electrode plate is accommodated in a bag-like separator formed of a polyethylene microporous film, and is composed of five pre-formed negative electrode plates and four pre-formed positive electrode plates per cell. An electrode plate group is formed. The electrode plate group is inserted into a battery case made of polypropylene to produce a lead storage battery having a nominal voltage of 12V. In order to evaluate the effect of suppressing the oxidative deterioration of the negative electrode active material by oil (initial discharge performance), the produced battery is stored for one month. Thereafter, an electrolytic solution is injected into the battery, and supplementary charging is performed at 0.2 CA for 2 hours. The nominal capacity of the lead acid battery is 30 Ah (5 hour rate).

In this lead-acid battery, the content of the first carbon material in the negative electrode material is 1.5 mass%, and the content of the second carbon material is 0.3 mass%. However, these values are obtained when the negative electrode plate of the produced lead storage battery is taken out and the carbon material contained in the negative electrode material is separated into the first carbon material and the second carbon material by the procedure described above. It is a value calculated | required as content of each carbon material contained in an electrode material (100 mass%). The ratio R2 / R1 is 57. The powder resistance R2 / R1 ratio is also obtained by the procedure described above. Furthermore, the specific surface area ratio S2 / S1 obtained by the above-described procedure is 30. The average aspect ratio of the first carbon material determined by the procedure described above is 23.

<Lead storage battery A2>
As the carbon material, only carbon black (average particle diameter D ₅₀ : 40 nm) is used, and the content of the second carbon material is 0.3% by mass. Except for the above, a lead storage battery is fabricated in the same manner as the lead storage battery A1.

<Lead storage battery A3>
Only carbon black (average particle diameter D ₅₀ : 40 nm) is used as the carbon material, and the content of the second carbon material is 1.0 mass%. Except for the above, a lead storage battery is fabricated in the same manner as the lead storage battery A1.

<< Lead storage battery A4 >>
Only carbon black (average particle diameter D ₅₀ : 40 nm) is used as the carbon material, and the content of the second carbon material is 1.0 mass%. The content of oil contained in 100% by mass of the negative electrode material of the pre-formed negative electrode plate is 1% by mass. Except for the above, a lead storage battery is fabricated in the same manner as the lead storage battery A1.

<Lead storage battery A5>
As the carbon material, only carbon black (average particle diameter D ₅₀ : 40 nm) is used, and the content of the second carbon material is 0.3% by mass. Do not add oil to the negative electrode paste. Except for the above, a lead storage battery is fabricated in the same manner as the lead storage battery A1.

<Lead storage battery A6>
Only carbon black (average particle diameter D ₅₀ : 40 nm) is used as the carbon material, and the content of the second carbon material is 1.0 mass%. Do not add oil to the negative electrode paste. Except for the above, a lead storage battery is fabricated in the same manner as the lead storage battery A1.

<Lead storage battery A7>
As the carbon material, only graphite (average particle diameter D ₅₀ : 110 μm) is used, and the content of the first carbon material is 1.5 mass%. Except for the above, a lead storage battery is fabricated in the same manner as the lead storage battery A1.

<Lead storage battery A8>
As the carbon material, only graphite (average particle diameter D ₅₀ : 110 μm) is used, and the content of the first carbon material is 1.5 mass%. Do not add oil to the negative electrode paste. Except for the above, a lead storage battery is fabricated in the same manner as the lead storage battery A1.
The following evaluation is performed for each lead-acid battery.

[Evaluation 1: PSOC life performance]
After performing a first discharge for 59 seconds with a first current and a second discharge for 1 second with a second current at 25 ° C., a charge for 60 seconds (maximum current 100 A) is performed with a voltage of 14V. The first current is a value obtained by multiplying 0.05CA by 18.3. The second current is 300A. Charging / discharging is repeated with this as one cycle. Pause for 40-48 hours every 3600 cycles. The terminal voltage at the end of discharge in the second discharge is measured, and when the terminal voltage becomes less than 7.2 V, it is determined that the life has been reached, and the number of cycles at that time is obtained. It represents with the ratio when the result of lead acid battery A2 is set to 100.

[Evaluation 2: Initial discharge performance]
At 25 ° C., discharge is performed at 0.2 CA until the terminal voltage reaches 1.7 V per unit cell, and the discharge time at this time is determined. This discharge time is used as an index of initial discharge performance. It represents with the ratio when the result of lead acid battery A2 is set to 100.

[Evaluation 3: Regeneration (charging) acceptance performance]
A fully charged lead acid battery is discharged at 25 ° C., 0.2 CA, and 10% of its nominal capacity, and then left at room temperature for 12 hours. Next, the battery is charged at a constant voltage of 2.42 V per unit cell, and the amount of electricity for the first 10 seconds at this time is obtained and used as an index of regenerative acceptance performance. It represents with the ratio when the result of lead acid battery A2 is set to 100.
The evaluation results are shown in Table 1.

In the case of only the second carbon material, when the content of the second carbon material increases to 1.0% by mass compared to the case where the content of the second carbon material is 0.3% by mass, oil is used. However, the initial discharge performance is reduced (A2, A3). On the other hand, when the first carbon material and the second carbon material are used in combination, by setting the powder resistance ratio R2 / R1 within a specific range, PSOC life performance can be obtained and 0.05% by mass or more Excellent initial discharge performance can be obtained with a small amount of oil addition of 1.0% by mass or less (A1). Since the oil addition amount may be as small as 1.0% by mass or less, high regeneration acceptance performance is ensured (A1).

In the case of only the first carbon material, the PSOC life performance is improved as compared with the case of only the second carbon material, but the initial discharge performance and the regenerative acceptance performance are reduced (A2, A7). When no oil is added, the initial discharge performance is greatly reduced (A5, A6, A8). In the case of only the second carbon material, the initial discharge performance improves when the oil content increases to 1.0% by mass, compared with the case where the oil content is 0.5% by mass. Performance decreases (A3, A4).

《Lead storage batteries B1 to B5》
In the same manner as lead acid battery A1, except that the content of oil contained in 100% by mass of the negative electrode material of the formed negative electrode plate is the value shown in Table 2 and the powder resistance ratio R2 / R1 is 11, A storage battery is made and evaluated.

《Lead storage batteries C1 to C5》
In the same manner as lead acid battery A1, except that the content of oil contained in 100% by mass of the negative electrode material of the formed negative electrode plate is set to the value shown in Table 2 and the powder resistance ratio R2 / R1 is set to 15. A storage battery is made and evaluated.

<< Lead storage battery D1 >>
A lead storage battery is produced and evaluated in the same manner as the lead storage battery A1, except that the powder resistance ratio R2 / R1 is 32.

《Lead storage batteries E1 to E5》
In the same manner as lead acid battery A1, except that the content of oil contained in 100% by mass of the negative electrode material of the formed negative electrode plate is the value shown in Table 2, and the powder resistance ratio R2 / R1 is 57, lead A storage battery is made and evaluated.

《Lead battery F1》
A lead storage battery is produced and evaluated in the same manner as the lead storage battery A1, except that the powder resistance ratio R2 / R1 is 83.

<Lead storage batteries G1-G5>
Lead is the same as lead storage battery A1 except that the content of oil contained in 100% by mass of the negative electrode material of the formed negative electrode plate is the value shown in Table 2 and the powder resistance ratio R2 / R1 is 103. A storage battery is made and evaluated.

《Lead battery H1》
A lead storage battery is produced and evaluated in the same manner as the lead storage battery A1, except that the powder resistance ratio R2 / R1 is set to 127.

<Lead storage batteries I1-I5>
Lead is the same as lead acid battery A1 except that the content of oil contained in 100% by mass of the negative electrode material of the formed negative electrode plate is the value shown in Table 2 and the powder resistance ratio R2 / R1 is 152. A storage battery is made and evaluated.

<Lead storage batteries J1-J5>
In the same manner as lead acid battery A1, except that the content of oil contained in 100% by mass of the negative electrode material of the formed negative electrode plate is the value shown in Table 2 and the powder resistance ratio R2 / R1 is 169, lead A storage battery is made and evaluated.
The evaluation results are shown in Table 2. In addition, the lead storage battery E3 in Table 2 is the lead storage battery A1.

When the oil content is in the range of 0.05 to 1.0% by mass and the powder resistance ratio R2 / R1 is in the range of 15 to 155, excellent PSOC life performance, initial discharge performance, and Regenerative acceptance performance is obtained (C2-C4, D1, E2-E4, F1, G2-G4, H1, I2-I4). When the oil content is in the range of 0.05% by mass or more and 0.5% by mass or less, PSOC life performance and regenerative acceptance performance are further improved (C2, C3, E2, E3, G2, G3, I2, I3). . In contrast to the example in which the oil content is 0.5% by mass, the PSOC life performance, initial discharge performance, and regenerative acceptance performance are more balanced when the powder resistance ratio R2 / R1 is in the range of 55 to 130. Is obtained (E3, F1, G3, H1).

<Lead storage batteries K1-K13>
Except that the content of oil contained in 100% by mass of the negative electrode material of the formed negative electrode plate is the value shown in Table 3, and the specific surface area ratio S2 / S1 is the value shown in Table 3, the same as the lead storage battery A1. Then, make and evaluate a lead-acid battery.
The evaluation results are shown in Table 3. In addition, the lead storage battery K3 in Table 3 is the lead storage battery A1.

When the specific surface area ratio S2 / S1 is in the range of 20 to 240, the PSOC life performance and the regenerative acceptance performance are further improved while maintaining the initial discharge performance (K3 to K11).

<Lead storage batteries L1 to L13>
The lead-acid battery A1 and the lead-acid battery A1 except that the oil content contained in 100% by mass of the negative electrode material of the formed negative electrode plate is the value shown in Table 4 and the average aspect ratio of the first carbon material is the value shown in Table 4. Similarly, a lead storage battery is produced and evaluated.
The evaluation results are shown in Table 4. Lead storage battery L8 in Table 4 is lead storage battery A1.

When the average aspect ratio of the first carbon material is in the range of 1.5 to 30, the PSOC life performance and the regenerative acceptance performance are further improved while maintaining the initial discharge performance (L3 to L11). When comparing the lead storage battery with an oil content of 0.5% by mass, the PSOC life performance, initial discharge performance, and charge acceptance performance are more balanced when the average aspect ratio of the first carbon material is in the range of 5 to 30. Is obtained (L5, L6, L8, L10).

The lead acid battery according to one aspect of the present invention can be applied to control valve type and liquid type lead acid batteries, and is suitably used as an industrial power storage device such as a power source for starting an automobile or a motorcycle or a natural energy storage application. Available.

DESCRIPTION OF SYMBOLS 1 Lead storage battery 2 Negative electrode plate 2a Negative electrode ear | edge part 3 Positive electrode plate 4 Separator 5 Positive electrode shelf part 6 Negative electrode shelf part 7 Positive electrode pillar 8 Through-connection body 9 Negative electrode pillar 11 Electrode board group 12 Battery case 13 Partition 14 Cell chamber 15 Cover 16 Negative terminal 17 Positive terminal 18 Liquid spout

Claims

A lead acid battery,
The lead storage battery includes a negative electrode plate and a positive electrode plate,
The negative electrode plate includes a negative electrode material containing a carbon material and oil,
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 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,
Content of the said oil in the said negative electrode material is a lead acid battery which is 0.05 mass% or more and 1 mass% or less.
The ratio of specific surface area S2 of said 2nd carbon material with respect to specific surface area S1 of said 1st carbon material: Lead acid battery of Claim 1 whose S2 / S1 is 20 or more.
The lead acid battery according to claim 1 or 2, wherein 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 240 or less.
The lead storage battery according to any one of claims 1 to 3, wherein an average aspect ratio of the first carbon material is 1.5 or more.
The lead storage battery according to any one of claims 1 to 4, wherein an average aspect ratio of the first carbon material is 30 or less.
The lead acid battery according to any one of claims 1 to 5, wherein the content of the first carbon material in the negative electrode material is 0.05 mass% or more.
The lead acid battery according to any one of claims 1 to 6, wherein a content of the first carbon material in the negative electrode material is 3.0 mass% or less.
The lead acid battery according to any one of claims 1 to 7, wherein a content of the second carbon material in the negative electrode material is 0.03% by mass or more.
The lead acid battery according to any one of claims 1 to 8, wherein a content of the second carbon material in the negative electrode material is 1.0 mass% or less.
The lead acid battery according to any one of claims 1 to 9, wherein the first carbon material includes at least graphite, and the second carbon material includes at least carbon black.