WO2018025837A1

WO2018025837A1 - Lead storage cell

Info

Publication number: WO2018025837A1
Application number: PCT/JP2017/027816
Authority: WO
Inventors: 賢稲垣; 真観京
Original assignee: 株式会社Ｇｓユアサ
Priority date: 2016-08-05
Filing date: 2017-08-01
Publication date: 2018-02-08
Also published as: CN109565040A; JP6844622B2; JPWO2018025837A1; CN109565040B

Abstract

A lead storage cell characterized in being provided with a positive electrode plate, a negative electrode plate, and an electrolytic solution, a negative electrode material of the negative electrode plate containing graphite or carbon fiber and barium element at an amount of 1.1 mass% or greater in terms of barium sulfate, and a positive electrode material of the positive electrode plate containing tin element.

Description

Lead acid battery

The present invention relates to a lead-acid battery.

The use of lead-acid batteries in an incompletely charged state (PSOC (Partial state of charge)) is increasing. For example, an idling stop (hereinafter abbreviated as “IS”) vehicle has been proposed in order to improve the fuel efficiency of an automobile, but the lead-acid battery is used in an insufficiently charged state in the IS vehicle. Even in applications other than IS vehicles, lead-acid batteries are often placed in an insufficiently charged state because charging to the lead-acid batteries is avoided in order to improve energy efficiency, and moreover, the power taken out from the lead-acid batteries is increasing.

In lead-acid batteries, sulfuric acid is consumed by the bipolar plates and water is generated at the positive electrode during discharge. In addition, sulfuric acid is released from the bipolar plates during charging. Since the specific gravity of sulfuric acid is greater than that of water, it tends to accumulate in the lower part of the lead-acid battery, resulting in a phenomenon (stratification) in which the sulfuric acid concentration of the electrolytic solution has a vertical difference. When the amount of charge is sufficient, stratification is eliminated because the electrolyte is stirred by the gas generated from the electrode plate at the end of charging.

However, in lead acid batteries used in PSOC, gas generation due to overcharging is small, so that stratification of the electrolyte is difficult to eliminate. At the bottom of the electrode plate where the sulfuric acid concentration is high, the charge acceptability is low, and sulfation (accumulation of lead sulfate) proceeds at the bottom of the negative electrode plate. Moreover, when the charge / discharge reaction is concentrated on the upper part of the electrode plate, the deterioration of the upper part of the positive electrode plate is promoted and the life performance is lowered.

It is known to add graphite to the negative electrode material in order to improve the charge acceptance of lead-acid batteries used in PSOC and improve the life performance.

In Patent Document 1, “in a lead storage battery using a paste type negative electrode plate in which a paste-like active material made of lead powder as a raw material is held in a lead alloy current collector, a carbonaceous material is contained in the negative electrode active material. A lead acid battery containing (a) a bisphenol sulfonic acid polymer and (b) sodium lignin sulfonate and characterized by the following points regarding the amount of (a) and (b): (a) and (b ) Is 100 parts by mass, the blending ratio of (a) is 50 to 80 parts by mass, and (a) and (b) are added to the mass of the raw material lead powder of the negative electrode active material. The blended mass is 0.05 mass% or more and 0.3 mass% or less. ”([Claim 1]),“ In the negative electrode active material, the average primary particle diameter is 10 μm or more as a carbonaceous material. The flaky graphite is contained. 4. The lead storage battery according to any one of claims 1 to 3] ([Claim 4]), "The content of the flake graphite is 0.5 mass% to 2 mass% with respect to the mass of the negative electrode active material in a fully charged state. 5. The lead acid battery according to claim 4, wherein the content is 5% by mass. ([Claim 5]), “Carbon black is contained in addition to the flake graphite. Of lead storage battery ”([Claim 6]).

Patent Document 2 discloses "a shrinkage-preventing agent for a storage battery paste for a storage battery electrode plate for a lead storage battery, which contains barium sulfate; a high concentration of carbon and / or graphite; and an organic substance." (Claim 1), "High The invention according to claim 1, wherein the concentration of carbon and / or graphite reduces lead sulfate accumulation on the surface of the negative electrode active material in the lead acid battery. Yes.

Patent Document 3 describes the invention of “an expansion agent for a storage battery paste characterized by containing barium sulfate, carbon, and an organic material, and the organic material is heat-decomposable.” (Claim 1) Represents any of carbon black, activated carbon or graphite, and mixtures thereof ”(paragraph [0029]).

It is also known to add tin to the positive electrode material and to specify the density of the positive electrode material in order to improve the performance of the lead storage battery used in PSOC.

In Patent Document 4, “a positive electrode plate made of a positive electrode active material and a positive electrode lattice, a negative electrode plate made of a negative electrode active material and a negative electrode lattice, a separator separating the positive electrode plate and the negative electrode plate, a positive electrode plate and a negative electrode plate are disclosed. In a liquid lead-acid battery for an idling stop vehicle that includes a liquid electrolyte that immerses the separator and has fluidity, the density of the positive electrode active material is 4.4 g / cm ³ or more and 4.8 g in the already formed state. / Cm ³ or less, and Sn is converted into metal Sn and contained 0.05 mass% or more and 1.0 mass% or less. The invention of “Liquid lead storage battery” (Claim 1) is described. ing.

Re-publication WO2012 / 017702 Special table 2012-501519 gazette Special table 2010-529619 JP 2013-140677 A

In a lead-acid battery, when graphite or carbon fiber (hereinafter sometimes referred to as “graphite or the like”) having relatively high conductivity and a particle size larger than that of carbon black or the like is contained in the negative electrode material, The life of the lead storage battery (hereinafter referred to as “PSOC life”) can be extended. On the other hand, the present inventors have found for the first time that a lead storage battery in which graphite or the like is contained in the negative electrode material has a problem that an infiltration short circuit is likely to occur. The reason is not necessarily clear, but is presumed as follows. Graphite and the like have a larger particle size than carbon black and the like, and a part of the graphite is easily exposed on the surface of the negative electrode plate. Since graphite or the like has a relatively high conductivity, when the graphite or the like is exposed on the surface of the negative electrode plate, the charge reaction of Pb ²⁺ occurs on the exposed portion. As a result, it is presumed that locally large dendritic lead grows in a direction that breaks through the separator, and a penetration short circuit occurs around the upper part of the electrode plate where the charging current tends to concentrate.

In view of the above problems, an object of the present invention is to provide a lead-acid battery with improved PSOC life performance and suppressed occurrence of permeation short circuit.

A lead storage battery according to an aspect of the present invention includes a positive electrode plate, a negative electrode plate, and an electrolyte solution. The negative electrode material of the negative electrode plate is graphite or carbon fiber, and a barium element of 1.1 mass% or more in terms of barium sulfate. The positive electrode material of the positive electrode plate contains a tin element.

According to one embodiment of the present invention, it is possible to provide a lead-acid battery with improved PSOC life performance and suppressed occurrence of permeation short circuit.

Sectional drawing of the principal part of the lead acid battery which concerns on 1 aspect of this invention. Characteristic chart showing influence of graphite content (barium content 1.0 mass% in terms of barium sulfate, positive electrode active material density 4.8 g / cm ³ , tin content 0 mass%) Characteristic diagram showing the effect of barium content (graphite content 1.0 mass%, tin content 0 mass%) Characteristic diagram showing influence of barium content and tin content (graphite content: 1.0 mass%, positive electrode active material density: 4.2 g / cm ³ ) Characteristic diagram showing influence of barium content and tin content (graphite content: 1.0 mass%, positive electrode active material density: 4.2 g / cm ³ ) Characteristic diagram showing influence of positive electrode active material density (graphite content: 1.0 mass%, barium content in terms of barium sulfate: 1.2 mass%) Characteristic diagram showing influence of positive electrode active material density (graphite content: 1.0 mass%, barium content in terms of barium sulfate: 1.0 mass%) Characteristic chart showing the effect of barium content (graphite content 1.0 mass%, tin content 0.01 mass%) The characteristic figure which shows the influence of carbon black content (graphite content 3.0mass%, positive electrode active material density 4.8g / cm < ³ >) Characteristic chart showing influence of average particle diameter of graphite (graphite content: 3.0 mass%, barium content: 1.2 mass% in terms of barium sulfate, positive electrode active material density: 4.8 g / cm ³ , tin content: 0.01 mass% )

A lead storage battery according to an aspect of the present invention includes a positive electrode plate, a negative electrode plate, and an electrolyte solution. The negative electrode material of the negative electrode plate is graphite or carbon fiber, and a barium element of 1.1 mass% or more in terms of barium sulfate. The positive electrode material of the positive electrode plate contains a tin element. Details will be described below.

The negative electrode plate is composed of a negative electrode current collector and a negative electrode material, the positive electrode plate is composed of a positive electrode current collector and a positive electrode material, and solid components other than the current collector belong to the electrode material. Hereinafter, the content of graphite, the content of carbon fiber, the content of barium element, and the content of carbon black are the content (mass%) with respect to the negative electrode material in a fully charged state after chemical conversion. Further, the content of tin element is the content (mass%) relative to the positive electrode material in a fully charged state after chemical conversion. In addition, content of barium element is content in barium sulfate conversion, and content of tin element is content in metal tin conversion.

In order to make a lead-acid battery fully charged, in the case of a liquid battery, after performing constant current charging in a water bath at 25 ° C. until it reaches 2.5 V / cell at a current rate of 5 hours, an additional 5 hours rate Charge with constant current for 2 hours. In the case of a control valve type battery, a constant current / constant voltage charge is performed at a current of 5 hours in a 25 ° C. air tank at a rate of 2.23 V / cell, and the current value during constant voltage charge is 1 mCA or less. When charging is finished. The 5-hour rate current in this specification is a current value for discharging the nominal capacity of the lead storage battery in 5 hours. For example, if the battery has a nominal capacity of 30 Ah, the 5-hour rate current is 6 A, and 1 mCA is 30 mA. .

<Electrode material>
As described above, the lead-acid battery including the negative electrode material containing graphite or the like has improved PSOC life performance.

If the content of graphite or the like in the negative electrode material is 0.5 mass% or more, the effect of improving the PSOC life performance is great. Therefore, the content of graphite or the like in the negative electrode material may be 0.5 mass% or more. preferable. If the content of graphite or the like in the negative electrode material is 1.0 mass% or more, the effect of improving the PSOC life performance is further increased. Therefore, the content of graphite or the like in the negative electrode material should be 1.0 mass% or more. Is more preferable.

When the content of graphite or the like in the negative electrode material is 2.5 mass% or less, it becomes easy to fill the negative electrode current paste into the negative electrode current collector, so the content of graphite or the like in the negative electrode material is It is preferable to set it as 2.5 mass% or less, and it is more preferable to set it as 2.0 mass% or less.

Examples of graphite include scaly graphite, scaly graphite, earthy graphite, expanded graphite, expanded graphite, and artificial graphite. Expanded graphite is expanded graphite. Carbon fiber may be used instead of graphite. Graphite and carbon fiber have a relatively high electrical conductivity and are common in that they are larger than carbon black and the like, and the action in the negative electrode material is considered to be the same. For example, the carbon fiber preferably has a length of 5 μm or more and 500 μm or less, and more preferably a length of 10 μm or more and 300 μm or less. The graphite or the like is preferably flaky graphite or expanded graphite, and more preferably flaky graphite.

When the average particle diameter of graphite is 300 μm or less, it is difficult for permeation short circuit to occur. Therefore, the average particle diameter of graphite is preferably 300 μm or less. Further, when the average particle diameter of graphite is 100 μm or more, the PSOC life performance is improved. Therefore, the average particle diameter of graphite is preferably 100 μm or more. In addition, the average particle diameter of graphite means the value of the particle diameter (D50) at which the cumulative volume is 50% in the particle size distribution when analyzed with a laser diffraction particle size distribution analyzer.

By adding graphite or the like to the negative electrode material, the PSOC life performance is improved, but an infiltration short circuit is likely to occur. It has not been known so far that an infiltration short circuit is likely to occur by adding graphite or the like to the negative electrode material of a lead storage battery. The inventors of the present invention have found that the occurrence of an infiltration short circuit can be suppressed by adding 1.1 mass% or more of barium element in terms of barium sulfate together with graphite or the like in the negative electrode material.

The effect that the penetration short circuit can be suppressed by adding 1.1 mass% or more of barium sulfate in addition to graphite or the like to the negative electrode material is unpredictable from the conventional technical common sense. This is because the problem that an osmotic short circuit is likely to occur by including graphite or the like in the negative electrode material has not been recognized so far, and the addition amount of barium element is selected to be 1.1 mass% or more in terms of barium sulfate. This is because the effect of suppressing the occurrence of the penetration short circuit has not been known so far.

The mechanism of action by which the addition of barium element to the negative electrode material suppresses the occurrence of permeation short circuit is not necessarily clear, but is presumed as follows. The barium element in the negative electrode material is dispersed almost uniformly inside the negative electrode material as barium sulfate and functions as a lead sulfate nucleating material during discharge, thereby generating lead sulfate also in the negative electrode material. When lead sulfate is generated inside the negative electrode material, it is possible to suppress an increase in the amount of lead sulfate generated on the surface of the negative electrode plate. Part of the lead sulfate dissolves to produce lead ions, but when the amount of lead sulfate on the surface of the negative electrode plate decreases, the concentration of lead ions near the surface of the negative electrode plate also decreases, and the lead ions are between the positive and negative electrode plates. Difficult to diffuse into the electrolyte. As a result, in the graphite exposed on the electrode plate surface, the reduction reaction of lead ions hardly occurs at the time of charging, and it is possible to suppress the growth of dendritic lead from the graphite exposed on the electrode plate surface toward the positive electrode plate. it is conceivable that.

When the content of barium element in the negative electrode material is 1.2 mass% or more in terms of barium sulfate, the occurrence of permeation short circuit can be greatly suppressed. Therefore, the barium element content in the negative electrode material is preferably 1.2 mass% or more in terms of barium sulfate.

If the content of barium element in the negative electrode material is 3.0 mass% or less in terms of barium sulfate, PSOC life performance is improved. Therefore, the content of barium element in the negative electrode material is 3.0 mass% in terms of barium sulfate. The following is preferable. If the barium element content in the negative electrode material is 2.5 mass% or less in terms of barium sulfate, the PSOC life performance is greatly improved. Therefore, the barium element content in the negative electrode material is 2.5 mass in terms of barium sulfate. % Or less is more preferable.

In order to contain barium element in the negative electrode material, single barium or a barium compound such as barium sulfate or barium carbonate may be added to the negative electrode material. Even if a single barium or barium compound other than barium sulfate is added to the negative electrode material, it is considered that it changes to barium sulfate after the addition.

The barium sulfate in the negative electrode material preferably has an average secondary particle size of 1 to 10 μm, for example. Further, the barium sulfate in the negative electrode material preferably has an average primary particle size of, for example, 0.3 to 2.0 μm.

When the content of the barium element in the negative electrode material is 1.1 mass% or more in terms of barium sulfate, and the positive electrode material further contains a tin element, the penetration short circuit can be further suppressed. On the other hand, when the content of barium element in the negative electrode material is 1.0 mass% or less in terms of barium sulfate, even if tin element is contained in the positive electrode material, the penetration short-circuit suppressing effect by the tin element is observed. Absent. It has not been known so far that the tin element in the positive electrode material is related to the penetration short circuit. Therefore, when the negative electrode material contains graphite or the like and contains a barium element of 1.1 mass% or more in terms of barium sulfate, it is expected that the penetration electrode short circuit can be suppressed by containing the tin element in the positive electrode material. It is not possible. In addition, since the content of barium element in the negative electrode material in terms of barium sulfate is 1.1 mass% or more and 1.0 mass% or less, the penetration short-circuit suppressing effect by the tin element clearly changes. It can be said that there is a critical significance in setting the barium element content in the negative electrode material to 1.1 mass% or more in terms of barium sulfate.

When the content of tin element in the positive electrode material is 0.01 mass% or more, the penetration short circuit can be remarkably suppressed. Therefore, the content of tin element in the positive electrode material is preferably 0.01 mass% or more. In addition, metals, oxides, sulfates, and the like can be considered as the presence form of the tin element in the positive electrode material.

The action mechanism in which the occurrence of permeation short circuit is suppressed by the addition of tin element to the positive electrode material is not necessarily clear, but is presumed as follows. Since tin element has the effect of increasing conductivity, the addition of tin element to the positive electrode material makes charge / discharge reactions in the vertical direction of the positive electrode plate more uniform, reducing the concentration of charging current on the top of the electrode plate. Is done. When the concentration of the charging current on the upper part of the electrode plate is relaxed, the growth of dendritic lead on the upper part of the electrode plate is suppressed, and synergistic with the penetration short-circuit suppressing effect by 1.1 mass% or more of barium sulfate in the negative electrode material. It is presumed that the occurrence of permeation short circuit is significantly suppressed.

When the negative electrode material contains graphite or the like and barium element of 1.1 mass% or more in terms of barium sulfate, if the content of tin element in the positive electrode material is 0.15 mass% or less, the positive electrode material is tin The PSOC life performance is improved as compared with the case where no element is contained. Therefore, it is preferable that the content of the tin element in the positive electrode material is 0.15 mass% or less. On the other hand, when the content of barium element in the negative electrode material is 1.0 mass% or less in terms of barium sulfate, the positive electrode material is used even if the content of tin element in the positive electrode material is 0.15 mass% or less. The PSOC life performance is not improved as compared with the case where no tin element is contained. When the negative electrode material contains graphite or the like, the PSCO life performance is improved by making the content of barium element in the negative electrode material and the content of tin element in the positive electrode material into a specific range. Is not known so far.

When the negative electrode material contains graphite or the like and barium element of 1.1 mass% or more in terms of barium sulfate, if the content of tin element in the positive electrode material is 0.10 mass% or less, the positive electrode material is tin Compared with the case where no element is contained, the PSOC life performance is greatly improved. Therefore, the content of tin element in the positive electrode material is more preferably 0.10 mass% or less. When the negative electrode material contains graphite or the like and barium element of 1.1 mass% or more in terms of barium sulfate, if the content of tin element in the positive electrode material is 0.08 mass% or less, PSOC life performance is further improved. It is further preferable because it greatly improves. When the negative electrode material contains graphite or the like and barium element of 1.1 mass% or more in terms of barium sulfate, if the content of tin element in the positive electrode material is 0.06 mass% or less, PSOC life performance is particularly good This is particularly preferable because it greatly improves.

When the negative electrode material contains graphite or the like and barium element of 1.1 mass% or more in terms of barium sulfate, if the content of tin element in the positive electrode material is 0.03 mass% or more, the positive electrode material is tin. Compared with the case where no element is contained, the PSOC life performance is greatly improved. Therefore, the content of tin element in the positive electrode material is preferably 0.03 mass% or more.

The effect of improving PSOC life performance obtained when the negative electrode material contains graphite or the like and barium element of 1.1 mass% or more in terms of barium sulfate and the positive electrode material contains tin element of 0.15 mass% or less is When the density of the positive electrode material is 3.6 g / cm ³ or more, the density increases. Therefore, the density of the positive electrode material is preferably 3.6 g / cm ³ or more. On the other hand, when the content of barium element in the negative electrode material is 1.0 mass% or less in terms of barium sulfate, even if the density of the positive electrode material is 3.6 g / cm ³ or more, the positive electrode material contains tin element. Compared with the case where it does not contain, the PSOC life performance is not improved.

The effect of improving PSOC life performance obtained when the negative electrode material contains graphite or the like and barium element of 1.1 mass% or more in terms of barium sulfate and the positive electrode material contains tin element of 0.15 mass% or less is When the density of the positive electrode material is 4.2 g / cm ³ or more, the density is further increased. Therefore, the density of the positive electrode material is more preferably 4.2 g / cm ³ or more. Improvement of the PSOC life performance since the density of the positive electrode material becomes significantly large when the 4.4 g / cm ³ or more, and particularly preferably the density of the positive electrode material 4.4 g / cm ³ or more .

When the density of the positive electrode material is 5.0 g / cm ³ or less, the initial capacity of the lead-acid battery is improved. Therefore, the density of the positive electrode material is preferably 5.0 g / cm ³ or less.

The lead storage battery according to one embodiment of the present invention may further contain carbon black in the negative electrode material. When the negative electrode material contains graphite and the barium element of 1.1 mass% or more in terms of barium sulfate, and the positive electrode material contains tin element, if the black electrode material further contains carbon black, the penetration short circuit Can be further suppressed. On the other hand, when the content of barium element in the negative electrode material is 1.0 mass% or less in terms of barium sulfate, or when the positive electrode material does not contain tin element, carbon black is contained in the negative electrode material. However, the effect of suppressing the penetration short circuit by carbon black cannot be obtained.

It is preferable that the content of carbon black in the negative electrode material is 0.1 mass% or more because the penetration short circuit can be largely suppressed. When the content of carbon black in the negative electrode material is 1.0 mass% or less, it becomes easy to fill the negative electrode current collector with the negative electrode material paste. Accordingly, the content of carbon black in the negative electrode material is preferably 1.0 mass% or less.

Hereinafter, a lead storage battery and a manufacturing method thereof according to an embodiment of the present invention will be described in detail.

<Negative electrode plate>
The unformed negative electrode plate can be produced as follows. First, water and sulfuric acid are added to lead powder to form a paste to obtain a negative electrode material paste. The negative electrode material paste may further contain graphite, carbon fiber, barium sulfate, carbon black, lignin as an anti-shrink agent, reinforcing materials such as synthetic resin fibers, and the like. Instead of barium sulfate, a barium compound such as single barium or barium carbonate may be used.

The content of lignin is arbitrary, and instead of lignin, a synthetic shrinking agent such as a sulfonated bisphenol condensate may be used. The content of the reinforcing material and the type of the synthetic resin fiber are arbitrary. Moreover, the kind of lead powder and manufacturing conditions are arbitrary. Other additives, a water-soluble synthetic polymer electrolyte, and the like may be included in the negative electrode material paste.

After filling the negative electrode current material paste into the negative electrode current collector, aging and drying are performed to produce an unformed negative electrode plate. For the negative electrode current collector, for example, an expanded lattice, a cast lattice, a punched lattice, or the like can be used.

<Positive electrode plate>
The non-chemically formed positive electrode plate can be produced as follows. First, water and sulfuric acid are added to lead powder to form a paste to obtain a positive electrode material paste. The positive electrode material paste may contain a reinforcing material such as tin sulfate or synthetic resin fiber. After filling this positive electrode material paste into the positive electrode current collector, aging and drying are performed to produce an unformed positive electrode plate. The kind of lead powder and manufacturing conditions are arbitrary. Instead of tin sulfate, metal tin or the like may be used, and it is presumed that tin is present as a metal, oxide, sulfate compound or the like in the positive electrode material. The density of the positive electrode material after the formation is adjusted by changing the amount of water added when preparing the positive electrode material paste. For the positive electrode current collector, for example, an expanded lattice, a cast lattice, a punched lattice, or the like can be used.
<Lead battery>

Lead acid battery can be manufactured as follows. An unformed negative electrode plate and an unformed positive electrode plate are alternately laminated via a separator, and the unformed negative electrode plates and the unformed positive electrode plates are connected by a strap to form an electrode plate group. The electrode plates are connected in series and accommodated in a cell chamber of a battery case, and sulfuric acid is added to form a lead acid battery. After forming the unformed negative electrode plate and the unformed positive electrode plate, the electrode plate group may be assembled to produce a lead storage battery. The separator is made of, for example, a synthetic resin, preferably made of polyolefin, and more preferably made of polyethylene. The separator preferably has a rib protruding from the base. The base thickness and total thickness of the separator are arbitrary, but the thickness of the separator base is preferably 0.15 mm or more and 0.25 mm or less. The distance between the positive electrode plate and the negative electrode plate is preferably 0.5 mm or more and 1.0 mm or less. You may enclose a positive electrode plate or a negative electrode plate by making a separator into a bag shape.

FIG. 1 shows a main part of an electrode plate group 1 of a lead storage battery according to one embodiment of the present invention, 2 is a negative electrode plate, 3 is a positive electrode plate, and 4 is a separator. The negative electrode plate 2 includes a negative electrode current collector 21 and a negative electrode material 22, and the positive electrode plate 3 includes a positive electrode current collector 31 and a positive electrode material 32. The separator 4 has a bag shape including a base 41 and ribs 42, the negative electrode plate 2 is accommodated inside the bag, and the ribs 42 face the positive electrode plate 3 side. However, the positive plate 3 may be accommodated in the separator 4 with the rib 42 facing the positive plate 3, or the separator 4 may not have the rib 42. The separator need not be in the form of a bag as long as the positive electrode plate and the negative electrode plate are separated from each other. For example, a leaflet-shaped glass mat or a retainer mat may be used.

The content of barium element contained in the negative electrode material after chemical conversion is quantified as follows. The fully charged lead acid battery is disassembled, the negative electrode plate is washed with water and dried to remove the sulfuric acid, and the negative electrode material is collected. The negative electrode material is pulverized, and 300 g / L of hydrogen peroxide water is added at 20 mL per 100 g of the negative electrode material, and nitric acid obtained by diluting 60 mass% of concentrated nitric acid with 3 times its volume of ion exchange water is added, Heat for 5 hours under stirring to dissolve lead as lead nitrate. Further, barium sulfate is dissolved, and the barium concentration in the obtained aqueous solution is quantified by atomic absorption measurement. Using this barium concentration, the barium content in terms of barium sulfate contained in the negative electrode material is calculated.

The contents of graphite and carbon black contained in the negative electrode material after chemical conversion are quantified as follows. The fully charged lead acid battery is disassembled, the negative electrode plate is washed with water and dried to remove the sulfuric acid, and the negative electrode material is collected. The negative electrode material is pulverized, and 300 g / L of hydrogen peroxide water is added at 20 mL per 100 g of the negative electrode material, and nitric acid obtained by diluting 60 mass% of concentrated nitric acid with 3 times its volume of ion exchange water is added, Heat for 5 hours under stirring to dissolve lead as lead nitrate. Furthermore, barium sulfate is dissolved. By filtering the obtained aqueous solution, solid components such as graphite, carbon black, and reinforcing material are separated.

Next, the solid component obtained by filtration is dispersed in water. Using a sieve through which the reinforcing material does not pass, the dispersion is sieved twice, washed with water to remove the reinforcing material, thereby separating carbon black and graphite.

In the negative electrode material paste, carbon black and graphite are added together with an organic shrinkage agent such as lignin. In the negative electrode material after conversion, carbon black and graphite are aggregated due to the surface active effect of the organic shrinkage agent. Exists in a collapsed state. In the above series of separation operations, the organic shrunk agent is eluted and lost in the water, so that the separated carbon black and graphite are dispersed again in water, and then the organic shrunk agent, Vanillex N (Nippon Paper Industries Co., Ltd.) is used as the lignin sulfonate. 15 g) is added to 100 mL of water and stirred, and the following separation operation is performed with the carbon black and graphite aggregates broken again.

After the above operation, the suspension containing carbon black and graphite is passed through a sieve through which carbon black does not substantially pass and graphite is separated. By this operation, graphite remains on the sieve, and carbon black is contained in the liquid that has passed through the sieve. After the graphite and carbon black separated by the above series of operations are washed with water and dried, the respective weights are weighed. Carbon fiber is also separated in the same manner as graphite and weighed.

The method for measuring the average particle diameter of graphite is shown below. As a measuring device, a laser diffraction particle size distribution measuring device SALD2200 manufactured by Shimadzu Corporation is used. First, graphite is dispersed in a dispersion prepared by mixing water and a surfactant, and the dispersion in which graphite is dispersed is irradiated with ultrasonic waves for 5 minutes using an ultrasonic cleaner. Next, the dispersion liquid in which graphite is dispersed is introduced into a batch cell and stirred for 1 minute. Thereafter, laser light is irradiated to obtain a particle size distribution of graphite. In the particle size distribution, the average particle size is the particle size at which the cumulative volume is 50% (D50) within the range where the minimum is set to 0.1 μm and the maximum is set to 1000 μm.

The content of tin element in the positive electrode material after chemical conversion is quantified as follows. The fully charged lead-acid battery is disassembled, the positive electrode plate is washed with water and dried to remove sulfuric acid, and the positive electrode material is collected. The positive electrode material is crushed, and 300 g / L of hydrogen peroxide water is added in an amount of 20 mL per 100 g of the positive electrode material, and nitric acid obtained by diluting 60 mass% of concentrated nitric acid with 3 times its volume of ion exchange water is added, Heat for 5 hours under stirring to dissolve lead and tin. The concentration of tin element in the obtained aqueous solution is quantified by ICP emission spectrometry, and the content of tin element in the positive electrode material is calculated.

The density of the positive electrode material means the value of the bulk density of the positive electrode material in a fully charged state after formation, and is measured as follows. The battery after chemical conversion is fully charged and then disassembled, and the obtained positive electrode plate is washed with water and dried to remove the electrolyte in the positive electrode plate. Next, the positive electrode material is separated from the positive electrode plate to obtain an unground measurement sample. After putting the sample into the measurement container and evacuating it, filling the mercury with a pressure of 0.5 to 0.55 psia, measuring the bulk volume of the positive electrode material, and dividing the mass of the measurement sample by the bulk volume The bulk density of the positive electrode material is obtained. The volume obtained by subtracting the injection volume of mercury from the volume of the measurement container is defined as the bulk volume.

The lead storage battery according to the present embodiment is excellent in PSOC life performance and is less likely to cause a penetration short circuit even when used in a partially charged state, and is therefore suitable for a lead storage battery used in a partially charged state such as a lead storage battery for an idling stop vehicle. . Moreover, the lead storage battery according to the present embodiment is suitable for a lead storage battery for cycle use such as for forklifts in addition to a lead storage battery for an idling stop vehicle. In the following embodiments, the lead storage battery is a liquid type, but may be a control valve type. The lead storage battery according to the present embodiment is preferably a liquid lead storage battery.

<Other embodiments>
The present invention is not limited to the above-described embodiment, and can be implemented in a mode in which various changes and improvements are made in addition to the above-described mode. For example, the present invention can be implemented in the following manner.

(1) A positive electrode plate, a negative electrode plate, and an electrolyte solution, wherein the negative electrode material of the negative electrode plate contains graphite or carbon fiber and 1.1 mass% or more of barium element in terms of barium sulfate, and the positive electrode plate The positive electrode material contains a tin element.

(2) The lead acid battery according to (1), wherein the positive electrode material contains 0.15 mass% or less of tin element.

(3) The lead acid battery according to (1) or (2), wherein the density of the positive electrode material is 3.6 g / cm ³ or more.

(4) The lead acid battery according to any one of (1) to (3), wherein the negative electrode material contains carbon black.

(5) The lead acid battery according to any one of (1) to (4), wherein the negative electrode material contains 0.5 mass% or more of graphite or carbon fiber.

(6) The lead acid battery according to any one of (1) to (5), wherein the negative electrode material contains 2.5 mass% or less of graphite or carbon fiber.

(7) The lead storage battery according to any one of (1) to (6), wherein the graphite or carbon fiber is graphite having an average particle size of 300 μm or less.

(8) The lead acid battery according to any one of (1) to (7), wherein the graphite or carbon fiber is graphite having an average particle diameter of 100 μm or more.

(9) The lead acid battery according to any one of (1) to (8), wherein the negative electrode material contains a barium element of 3.0 mass% or less in terms of barium sulfate.

(10) The lead acid battery according to any one of (1) to (9), wherein the positive electrode material contains 0.01 mass% or more of tin element.

(11) The lead acid battery according to any one of (1) to (10), wherein the density of the positive electrode material is 4.2 g / cm ³ or more.

(12), wherein the density of the positive electrode material is 5.0 g / cm ³ or less, one of the lead storage battery (1) to (11).

(13) The lead acid battery according to any one of (1) to (12), wherein the negative electrode material contains 1.0 mass% or more of graphite or carbon fiber.

(14) The lead acid battery according to any one of (1) to (13), wherein the negative electrode material contains 2.0 mass% or less of graphite or carbon fiber.

(15) The lead acid battery according to any one of (1) to (14), wherein the negative electrode material contains 1.2 mass% or more of barium element in terms of barium sulfate.

(16) The lead acid battery according to any one of (1) to (15), wherein the negative electrode material contains a barium element of 2.5 mass% or less in terms of barium sulfate.

(17) The lead acid battery according to any one of (1) to (16), wherein the barium element is contained as barium sulfate.

(18) The lead acid battery according to any one of (1) to (17), wherein the positive electrode material contains tin element of 0.10 mass% or less.

(19) The lead acid battery according to any one of (1) to (18), wherein the positive electrode material contains a tin element of 0.08 mass% or less.

(20) The lead acid battery according to any one of (1) to (19), wherein the positive electrode material contains a tin element of 0.06 mass% or less.

(21) The lead acid battery according to any one of (1) to (20), wherein the positive electrode material contains 0.03 mass% or more of a tin element.

(22) The lead acid battery according to any one of (1) to (21), wherein the density of the positive electrode material is 4.4 g / cm ³ or more.

(23) The lead acid battery according to any one of (1) to (22), wherein the negative electrode material contains 0.1 mass% or more of carbon black.

(24) The lead acid battery according to any one of (1) to (23), wherein the negative electrode material contains carbon black of 1.0 mass% or less.

(25) A positive electrode plate, a negative electrode plate, and an electrolyte solution, wherein the negative electrode material of the negative electrode plate contains graphite or carbon fiber and about 1.1 mass% or more of barium element in terms of barium sulfate, and the positive electrode A lead-acid battery characterized in that the positive electrode material of the plate contains a tin element.

(26) The lead acid battery according to (25), wherein the positive electrode material contains about 0.15 mass% or less of tin element.

(27), wherein the density of the positive electrode material is about 3.6 g / cm ³ or more, lead-acid battery (25) or (26).

(28) The lead-acid battery according to any one of (25) to (27), wherein the negative electrode material contains about 0.5 mass% or more of graphite or carbon fiber.

(29) The lead acid battery according to any one of (1) to (28), wherein the graphite or carbon fiber is scaly graphite or expanded graphite.

(30) The lead acid battery according to any one of (1) to (29), wherein the graphite or carbon fiber is scaly graphite.

(31) The lead acid battery according to any one of (1) to (30), wherein the lead acid battery is a lead acid battery used in a partially charged state.

(32) The lead acid battery according to any one of (1) to (31), wherein the lead acid battery is a liquid type lead acid battery.

(33) The lead acid battery according to any one of (1) to (31), wherein the lead acid battery is a control valve type lead acid battery.

(34) The lead acid battery according to any one of (1) to (33), wherein the lead acid battery is a lead acid battery for an idling stop vehicle.

(35) A vehicle equipped with any one of the lead acid batteries of (1) to (34).

Examples are shown below. In implementation, the embodiments can be appropriately changed in accordance with common sense of those skilled in the art and disclosure of prior art. In Examples, the negative electrode material may be referred to as a negative electrode active material, and the positive electrode material may be referred to as a positive electrode active material.

A lead powder produced by the ball mill method has a predetermined amount of flaky graphite (average particle size (D50) is 10 to 500 μm), a predetermined amount of barium sulfate (average primary particle size is 0.79 μm, average secondary particle size is 2.5μm), a predetermined amount of carbon black, a lignin (content 0.2 mass%) as a shrink-preventing agent, and a synthetic resin fiber (content 0.1 mass%) as a reinforcing material are mixed and pasted with water and sulfuric acid. Thus, a negative electrode active material paste was prepared. The content of flaky graphite was changed in the range of 0 mass% to 3.0 mass%. The content of barium sulfate was varied in the range of 1.0 mass% to 4.0 mass%. The carbon black content was varied in the range of 0 mass% to 0.5 mass%.

The prepared negative electrode active material paste is filled in an expanded negative electrode grid (height 110 mm × width 100 mm × thickness 1.0 mm) made of a Pb—Ca—Sn alloy that does not contain antimony, and subjected to aging and drying. A non-chemically formed negative electrode plate was prepared.

The lead powder produced by the ball mill method is mixed with a predetermined amount of tin sulfate and a synthetic resin fiber of 0.1 mass% reinforcing material (content: 0.1 mass%), and the mixture is made into a paste with water and sulfuric acid to produce a positive electrode active material. A material paste was prepared. The content of tin sulfate was varied in the range of 0 to 0.3 mass% in terms of metal tin. The prepared positive electrode active material paste is filled into an expanded positive electrode lattice (height 110 mm × width 100 mm × thickness 1.2 mm) made of a Pb—Ca—Sn alloy that does not contain antimony, and is subjected to aging and drying. A non-chemically formed positive electrode plate was produced. The density of the positive electrode active material after the chemical conversion by changing the amount of water to be added upon paste was adjusted to below 3.4 g / cm ³ or more 5.0 g / cm ^3.

A non-formed negative electrode plate is wrapped with a polyethylene separator (average pore diameter of 0.1 μm) with ribs protruding from the base, and 7 unformed negative plates and 6 unformed positive plates are alternately laminated. The positive electrode plates were connected to each other with a strap to form an electrode plate group. In the examples, a separator having a base thickness of 0.25 mm was used, and the distance between the positive electrode plate and the negative electrode plate was 0.7 mm. Six electrode plate groups connected in series are accommodated in a cell chamber of a battery case, and sulfuric acid having a specific gravity of 1.285 is added at 20 ° C. to form in the battery case. The liquid lead-acid battery was used.

The barium element content, graphite content, graphite average particle diameter, and carbon black content in the negative electrode active material were measured as described above. A sieve having a diameter of 1.4 mm was used to separate the carbon black and graphite in the negative electrode active material from the reinforcing material. After the separated carbon black and graphite are dispersed in water, vanillox N (manufactured by Nippon Paper Industries Co., Ltd.), which is a lignin sulfonate, is added as an organic anti-shrink agent, and carbon black and graphite are mixed using a sieve having a diameter of 20 μm. separated. In addition, about the lead storage battery provided with the negative electrode plate with the same composition, it measured by selecting one of those lead storage batteries, and the measurement result applied to all the lead storage batteries provided with the negative electrode plate of the same composition. Moreover, the content of the tin element contained in the positive electrode active material and the measurement of the positive electrode active material density were performed as described above. About the lead acid battery provided with the positive electrode plate with the same composition, one of those lead acid batteries was selected and measured, and the measurement result was applied to all the lead acid batteries provided with the positive electrode plate of the same composition.

The PSOC life test and the penetration short circuit acceleration test were performed on the fully charged lead acid battery. Table 1 shows the contents of the PSOC life test. 1CA is 30 A for a battery with a nominal capacity of 30 Ah. “40 ° C. gas” indicates that the test was conducted in a 40 ° C. air tank. The contents of the PSOC life test are as follows. First, a constant current discharge (step 1) at 1 CA for 59 seconds and a constant current discharge (step 2) at 300 A for 1 second are performed. Next, constant voltage charging (step 3) for 10 seconds at a voltage of 2.4 V per cell (charging current is 50 A at the maximum) and constant current discharging for 5 seconds at 1 CA (step 4) are performed. Steps 3 and 4 are repeated 5 times in total (Step 5), and Steps 1 to 5 are further repeated 50 times in total (Step 6). After step 6 is completed, constant voltage charging (step 7) is performed for 900 seconds at a voltage of 2.4 V per cell (the charging current is 50 A at the maximum). Steps 1 to 7 are repeated a total of 72 times (Step 8), and after a 15-hour pause (Step 9), the process returns to Step 1 (Step 10). Steps 1 to 10 are repeated until the terminal voltage reaches 1.2 V / cell, and the number of cycles when the terminal voltage reaches 1.2 V / cell is defined as the number of PSOC lifetimes. It should be noted that steps 1 to 5 are one cycle. For example, when Step 1 to Step 10 are performed once, the number of cycles is 3600 cycles.

Table 2 shows the contents of the penetration short circuit acceleration test. This test is a test performed under conditions that promote the occurrence of permeation shorts, and the incidence of permeation shorts is significantly higher than the actual use conditions of lead-acid batteries. The details of the penetration short circuit acceleration test are as follows. First, constant current discharge is performed at 0.05 CA until the voltage per cell reaches 1.0 V (step 1). Next, a resistance of 10Ω is connected between the positive electrode terminal and the negative electrode terminal of the lead-acid battery, and left in that state for 23 hours and 50 minutes (step 2). Thereafter, constant voltage charging is performed at a voltage of 2.4 V per cell for 10 minutes (maximum charging current is 50 A) (step 3). After repeating step 2 and step 3 a total of 5 times (step 4), the lead storage battery was disassembled and the proportion of lead storage batteries in which a short circuit occurred was examined. In addition, "25 degreeC water" shows having tested in the 25 degreeC water tank. In Tables 1 and 2, CC discharge means constant current discharge, CV charge means constant voltage charge, and CC charge means constant current charge.

Tables 3 to 10 show the results of the PSOC life test and the penetration short circuit acceleration test. In Tables 3 to 10, the PSOC life frequency represents the ratio of the PSOC life frequency of each battery when the PSOC life frequency of the battery A1 in Table 3 is 100. The PSOC life ratio represents the ratio of the number of PSOC life of each battery to the number of PSOC life of the first battery in each table.

From Table 5 and FIG. 2, it can be seen that the lead-acid battery containing graphite as the negative electrode active material has improved PSOC life performance as compared with the lead-acid battery except for the graphite content under the same conditions. When the negative electrode active material contains 0.5 mass% or more of graphite, the PSOC life performance is greatly improved, and when the negative electrode active material contains 1.0 mass% or more of graphite, the PSOC life performance is further improved.

On the other hand, it can be seen from Tables 3 to 6 and FIG. 2 that lead-acid batteries containing graphite as the negative electrode active material are more likely to cause penetration short circuits than lead-acid batteries other than the graphite content under the same conditions. Thus, it has not been known so far that when the negative electrode active material contains graphite, an osmotic short circuit is likely to occur.

From Tables 3 to 6 and FIG. 3, it can be seen that when the negative electrode active material contains barium element of 1.1 mass% or more in terms of barium sulfate, the permeation short circuit can be suppressed. When the negative electrode active material contains 1.2 mass% or more of barium element in terms of barium sulfate, the penetration short circuit can be greatly suppressed.

From Table 3 to Table 6 and Fig. 4, when the content of barium element in the negative electrode active material is 1.1 mass% or more in terms of barium sulfate, the positive electrode active material contains tin element to greatly suppress the penetration short circuit. I understand that I can do it. When the content of tin element in the positive electrode active material is 0.01 mass% or more, the permeation short circuit can be remarkably suppressed. On the other hand, when the content of barium element in the negative electrode active material is 1.0 mass% or less in terms of barium sulfate, even if the positive electrode active material contains tin element, the effect of suppressing penetration short circuit by tin element is not obtained. .

It has not been known so far that barium element in the negative electrode active material and tin element in the positive electrode active material are related to the penetration short circuit. Therefore, when the content of the barium element in the negative electrode active material is 1.1 mass% or more in terms of barium sulfate, it is not expected that the penetration short circuit can be remarkably suppressed by containing the tin element in the positive electrode active material. . In addition, since the content of barium element in the negative electrode material is 1.1 mass% or more in terms of barium sulfate and 1.0 mass% or less, the penetration short circuit suppression effect by the tin element clearly changes. It can be said that it is critical that the content of the barium element in the negative electrode material is 1.1 mass% or more in terms of barium sulfate.

From Tables 3 to 6 and FIG. 5, when the content of barium element in the negative electrode active material is 1.1 mass% or more in terms of barium sulfate, the content of tin element in the positive electrode active material is 0.15 mass% or less. It can be seen that the PSOC life performance is improved as compared with the case where the positive electrode active material does not contain tin element. When the content of tin element in the positive electrode active material is 0.10 mass% or less, the PSOC life performance is greatly improved. When the content of tin element in the positive electrode active material is 0.08 mass% or less, the PSOC life performance is improved. If the tin element content in the positive electrode active material is further improved and the content of tin element is 0.06 mass% or less, the PSOC life performance is particularly greatly improved. On the other hand, when the content of barium element in the negative electrode active material is 1.0 mass% or less in terms of barium sulfate, the positive electrode active material can be obtained even if the content of tin element in the positive electrode active material is 0.15 mass% or less. Compared with the case where no tin element is contained, the PSOC life performance is not improved.

When the negative electrode material contains graphite or the like, PSOC life performance is improved by setting the content of barium element in the negative electrode material and the content of tin element in the positive electrode material to a specific range. Has not been known so far and is an unexpected result.

From Tables 3 to 6 and FIG. 6, the negative electrode active material contains graphite and a barium element of 1.1 mass% or more in terms of barium sulfate, and the positive electrode active material contains a tin element of 0.15 mass% or less. It can be seen that the effect of improving the obtained PSOC life performance is increased when the density of the positive electrode active material is 3.6 g / cm ³ or more. When the density of the positive electrode active material is 4.2 g / cm ³ or more, the effect of improving the PSOC life performance is further increased. When the density of the positive electrode active material is 4.4 g / cm ³ or more, the effect of improving the PSOC life performance is increased. Becomes significantly larger. On the other hand, when the barium element content in the negative electrode active material is 1.0 mass% or less in terms of barium sulfate, the PSOC life performance is not improved even if the density of the positive electrode active material is 3.6 g / cm ³ or more (see FIG. 7).

From Tables 3 to 6 and FIG. 8, it can be seen that when the content of barium element in the negative electrode active material is 3.0 mass% or less in terms of barium sulfate, PSOC life performance is improved.

Table 7 and FIG. 9 show the results when carbon black is contained in the negative electrode active material. From Table 7 and FIG. 9, when the negative electrode active material contains barium element of 1.1 mass% or more in terms of graphite and barium sulfate, and the positive electrode active material contains tin element, the negative electrode active material contains carbon black. It can be seen that the penetration short circuit can be further suppressed. When the carbon black content in the negative electrode active material is 0.1 mass% or more, the penetration short circuit can be largely suppressed. On the other hand, when the content of barium element in the negative electrode active material is 1.0 mass% or less in terms of barium sulfate, or when the positive electrode active material does not contain tin element, the effect of suppressing the penetration short circuit by carbon black is not obtained. .

Table 8 and FIG. 10 show the results when the average particle diameter of graphite in the negative electrode active material is changed. It can be seen from Table 8 and FIG. 10 that the penetration short circuit can be suppressed when the average particle diameter of graphite in the negative electrode active material is 300 μm or less. It can also be seen that the PSOC life performance is improved when the average particle size of graphite in the negative electrode active material is 100 μm or more.

Tables 9 and 10 show the results when expanded anode graphite was made to contain expanded graphite instead of scaly graphite. From Tables 9 and 10, it can be seen that the same results can be obtained even if expanded graphite is used instead of flaky graphite.

In the examples, a liquid type lead storage battery with few permeation short circuits was obtained, but a control valve type lead storage battery may be used with the separator as a glass mat or the like.

Since the present invention can provide a lead storage battery with improved PSOC life performance and suppressed penetration short circuit occurrence, it is useful for IS vehicle applications that are often placed in a state of insufficient charging.

DESCRIPTION OF SYMBOLS 1 Electrode plate group 2 of lead acid battery Negative electrode plate 3 Positive electrode plate 4 Separator 21 Negative electrode collector 22 Negative electrode material 31 Positive electrode collector 32 Positive electrode material 41 Base 42 Rib

Claims

A positive electrode plate, a negative electrode plate, and an electrolyte;
The negative electrode material of the negative electrode plate contains graphite or carbon fiber and barium element of 1.1 mass% or more in terms of barium sulfate,
The lead-acid battery, wherein the positive electrode material of the positive electrode plate contains tin element.
The lead-acid battery according to claim 1, wherein the positive electrode material contains 0.15 mass% or less of tin element.
The lead acid battery according to claim 1, wherein the positive electrode material has a density of 3.6 g / cm 3 or more.
The lead acid battery according to any one of claims 1 to 3, wherein the negative electrode material contains carbon black.
The lead-acid battery according to any one of claims 1 to 4, wherein the negative electrode material contains 0.5 mass% or more of graphite or carbon fiber.
The lead acid battery according to any one of claims 1 to 5, wherein the negative electrode material contains 2.5 mass% or less of graphite or carbon fiber.
7. The lead acid battery according to claim 1, wherein the graphite or carbon fiber is graphite having an average particle diameter of 300 μm or less.
The lead-acid battery according to any one of claims 1 to 7, wherein the graphite or carbon fiber is graphite having an average particle diameter of 100 µm or more.
The lead-acid battery according to any one of claims 1 to 8, wherein the negative electrode material contains a barium element of 3.0 mass% or less in terms of barium sulfate.
The lead-acid battery according to any one of claims 1 to 9, wherein the positive electrode material contains 0.01 mass% or more of a tin element.
11. The lead acid battery according to claim 1, wherein the density of the positive electrode material is 4.2 g / cm 3 or more.
The lead acid battery according to any one of claims 1 to 11, wherein the density of the positive electrode material is 5.0 g / cm 3 or less.
The lead acid battery according to any one of claims 1 to 12, wherein the lead acid battery is a lead acid battery used in a partially charged state.
14. The lead storage battery according to claim 1, wherein the lead storage battery is a liquid lead storage battery.
A vehicle equipped with the lead storage battery according to any one of claims 1 to 14.