JPWO2018025837A1 - Lead storage battery - Google Patents

Abstract

A positive electrode plate, a negative electrode plate, and an electrolytic solution, wherein the negative electrode material of the negative electrode plate contains graphite or carbon fiber and at least 1.1 mass% of a barium element in terms of barium sulfate, A lead storage battery characterized in that the material contains a tin element. [Selected figure] Figure 4

Description

  The present invention relates to a lead-acid battery.

  Applications for using lead storage batteries in a partial state of charge (PSOC) are increasing. For example, in order to improve the fuel efficiency of a car, an idling stop (Idling-Stop, hereinafter abbreviated as IS) car has been proposed, but in an IS car, a lead storage battery is used in a state of insufficient charge. Other than for IS car applications, lead-acid batteries are often undercharged because charging of lead-acid batteries is avoided to improve energy efficiency, and the power drawn from lead-acid batteries is increasing.

  In the lead storage battery, at the time of discharge, sulfuric acid is consumed by the bipolar plates and water is generated at the positive electrode. Also, sulfuric acid is released from the bipolar plate during charging. Since sulfuric acid has a specific gravity greater than that of water, it tends to accumulate in the lower part of the lead-acid battery, causing a phenomenon (stratification) in which the concentration of sulfuric acid in the electrolytic solution is different up and down. When the amount of charge is sufficient, the electrolytic solution is agitated by the gas generated from the electrode plate at the end of charge, and the stratification is eliminated.

However, in the lead storage battery used in PSOC, the gas generation due to overcharging is small, so that stratification of the electrolyte solution is difficult to eliminate. At the lower part of the electrode plate where the concentration of sulfuric acid is high, the charge acceptance becomes low, and sulfation (accumulation of lead sulfate) progresses at the lower part of the negative electrode plate. In addition, since the charge / discharge reaction is concentrated on the upper portion of the electrode plate, deterioration of the upper portion 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 chargeability of lead-acid batteries used in PSOC and to improve the life performance.

  Patent Document 1 describes that “a lead-acid battery using a paste-type negative electrode plate formed by holding a paste-like active material made from lead powder as a raw material on a lead alloy current collector; A lead-acid battery containing (a) a bisphenol sulfonic acid polymer and (b) sodium lignin sulfonate together with the compounding amounts of (a) and (b) as follows: (a) and (b) The total content of (a) and (b) is 50 to 80 parts by mass, and the total of (a) and (b) is 100 parts by mass with respect to the mass of the raw material lead powder of the negative electrode active material. The compounding mass is set to 0.05% by mass or more and 0.3% by 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 flake-like graphite of the present invention is contained. 3. The lead storage battery according to any of 3. (Claim 4), "The content of the scaly graphite is 0.5% by mass to 2.5% with respect to the mass of the negative electrode active material in a fully charged state. The lead-acid battery according to claim 4, characterized in that it is mass%. ([Claim 5]), "A carbon black is contained in addition to the scaly graphite according to claim 5, characterized in that The invention of "lead-acid battery" ([claim 6]) is described.

  Patent Document 2 describes "Bammonium sulfate; High concentration of carbon and / or graphite; and a shrink-proofing agent for a battery paste for a battery plate for a lead-acid battery, which contains an organic substance" (claim 1), "High. The anti-shrink agent according to claim 1, wherein the concentration of carbon and / or graphite reduces the accumulation of lead sulfate on the surface of the negative electrode active material in a lead-acid battery. There is.

  Patent Document 3 relates to the invention of "the expanding agent for a storage battery paste characterized by containing barium sulfate, carbon and an organic material, and the organic material is heat-resistant and degradable." Represents either carbon black, activated carbon or graphite, and mixtures thereof. ”(Paragraph [0029]).

  Moreover, in order to improve the performance of a lead storage battery used in PSOC, it is known to add tin to the positive electrode material and to specify the density of the positive electrode material.

In Patent Document 4, “a positive plate consisting of a positive electrode active material and a positive grid, a negative plate consisting of a negative electrode active material and a negative grid, a separator for separating the positive plate and the negative plate, a positive plate and a negative plate Liquid lead-acid battery having a fluid electrolyte and a liquid electrolyte for immersing the separator and the separator, the positive electrode active material having a density of 4.4 g / cm ³ or more and 4.8 g in the state of being chemically converted. / cm ³ or less, and the is characterized in that it contains less 1.0 mass% or more 0.05 mass% in terms of metal Sn Sn, the liquid-type lead-acid battery. "is described invention for (claim 1) ing.

Republished WO2012 / 017702 Japanese Patent Application Publication No. 2012-501519 Japanese Patent Publication No. 2010-529619 JP, 2013-140677, A

In lead-acid batteries, when graphite or carbon fiber (hereinafter sometimes referred to as “graphite etc.”) having relatively high conductivity and large particle diameter compared to carbon black etc. is included in the negative electrode material, PSOC conditions Life of the lead-acid 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 a negative electrode material has a problem that the osmotic 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 diameter than carbon black and the like, and thus part of the graphite and the like are easily exposed on the surface of the negative electrode plate. Since graphite and the like have relatively high conductivity, when the graphite and the like are exposed on the surface of the negative electrode plate, the charging reaction of Pb ²⁺ is concentrated and occurs on the exposed portion. As a result, it is inferred that large dendritic lead, which grows locally, grows in a direction to break through the separator, and a penetration short circuit occurs around the upper part of the plate where the charging current tends to be concentrated.

  An object of the present invention is to provide a lead-acid battery in which PSOC life performance is improved and occurrence of a penetration short circuit is suppressed in view of the above-mentioned problems.

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

  According to one aspect of the present invention, it is possible to provide a lead-acid battery in which PSOC life performance is improved and the occurrence of osmotic short circuit is suppressed.

Principal part sectional view of lead acid battery concerning one mode of the present invention Characteristic diagram showing the influence of the graphite content (barium content in terms of barium sulfate: 1.0 mass%, positive electrode active material density: 4.8 g / cm ³ , tin content: 0 mass%) Characteristic diagram showing the influence 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 1.2 mass% in terms of barium sulfate) Characteristic diagram showing the influence of positive electrode active material density (graphite content 1.0 mass%, barium content 1.0 mass% in terms of barium sulfate) Characteristic chart showing the effect of barium content (graphite content 1.0 mass%, tin content 0.01 mass%) Characteristic chart (graphite content 3.0 mass%, positive electrode active material density 4.8 g / cm ³ ) showing the influence of carbon black content Characteristic diagram showing the influence of the 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% )

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

  The negative electrode plate consists of a negative electrode current collector and a negative electrode material, the positive electrode plate consists 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 fibers, the content of barium element, and the content of carbon black are the content (mass%) with respect to the fully charged negative electrode material after formation. In addition, the content of tin element is the content (mass%) of the fully charged positive electrode material after formation. The content of the barium element is the content in terms of barium sulfate, and the content of the tin element is the content in terms of metal tin.

  In order to make the lead storage battery fully charged, in the case of a liquid battery, after performing constant current charge until it reaches 2.5 V / cell at a 5 hour rate current in a water tank at 25 ° C., an additional 5 hour rate Perform constant current charging for 2 hours with current. Also, in the case of a control valve type battery, constant current constant voltage charging is performed with a 5-hour rate current, 2.23 V / cell in a 25 ° C. air tank, and the current value during constant voltage charging becomes 1 mCA or less. At the same time, charging ends. The 5-hour rate current in this specification is a current value that discharges the nominal capacity of a lead-acid battery in 5 hours, for example, in the case of a battery with 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 storage battery including the negative electrode material containing graphite and the like has improved PSOC life performance.

  When the content of graphite and the like in the negative electrode material is 0.5 mass% or more, the effect of improving PSOC life performance is large, so the content of graphite and the like in the negative electrode material may be 0.5 mass% or more. preferable. If the content of graphite and the like in the negative electrode material is 1.0 mass% or more, the effect of improving the PSOC life performance is even greater, so the content of graphite and the like in the negative electrode material should be 1.0 mass% or more. Is more preferred.

  When the content of the graphite and the like in the negative electrode material is 2.5 mass% or less, the negative electrode material paste can be easily filled into the negative electrode current collector, so the content of the graphite and the like in the negative electrode material is The content is preferably 2.5 mass% or less, and more preferably 2.0 mass% or less.

  Examples of the graphite include scale-like graphite, scale-like graphite, earth-like graphite, expanded graphite, expanded graphite, artificial graphite and the like. Expanded graphite is expanded graphite. Also, carbon fiber may be used instead of graphite. Graphite and carbon fibers are relatively high in conductivity, and they are common in that they are larger than carbon black and the like, and the function in the negative electrode material is considered to be the same. For example, the carbon fiber preferably has a length of 5 μm to 500 μm, and more preferably a length of 10 μm to 300 μm. The graphite and the like are preferably scale-like graphite or expanded graphite, and more preferably scale-like graphite.

  When the average particle size of graphite is 300 μm or less, it is difficult to cause an osmotic short circuit. Therefore, the average particle size of graphite is preferably 300 μm or less. When the average particle size of graphite is 100 μm or more, the PSOC life performance is improved, so the average particle size of graphite is preferably 100 μm or more. The average particle size of the graphite means the value of the particle size (D50) at which the cumulative volume is 50% in the particle size distribution when analyzed by a laser diffraction type particle size distribution measuring device.

  By adding graphite or the like to the negative electrode material, while the PSOC life performance is improved, osmotic short circuit is likely to occur. It has not been known until now that penetration shorting tends to occur easily by adding graphite or the like to the negative electrode material of a lead storage battery. The present inventors have found that the occurrence of osmotic short circuit can be suppressed by incorporating a barium element of 1.1 mass% or more in terms of barium sulfate together with graphite and the like in the negative electrode material.

  The effect that permeation short circuit can be suppressed by adding a barium element of 1.1 mass% or more in terms of barium sulfate together with graphite etc. to the negative electrode material can not be predicted from the common technical knowledge so far. This is because the inclusion of graphite or the like in the negative electrode material has not been recognized to be a problem that osmotic shorting tends to occur, and the addition amount of the 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 osmotic short circuit has not been known until now.

  The mechanism by which the addition of the barium element to the negative electrode material suppresses the occurrence of the osmotic short circuit is not necessarily clear, but is presumed as follows. The barium element in the negative electrode material is dispersed substantially uniformly as barium sulfate inside the negative electrode material, and functions as a nucleation agent of lead sulfate at the time of discharge to form lead sulfate also inside the negative electrode material. When lead sulfate is also 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. Although a part of lead sulfate dissolves to generate lead ions, when the amount of lead sulfate on the surface of the negative electrode plate decreases, the concentration of lead ion near the surface of the negative electrode plate also decreases, and the lead ions between positive and negative electrode plates It becomes difficult to diffuse in the electrolyte. As a result, in graphite and the like exposed on the surface of the electrode plate, the reduction reaction of lead ions is less likely to occur during charging, and it is possible to suppress the growth of dendritic lead in the direction of the positive electrode plate from the graphite and the like exposed on the electrode surface. it is conceivable that.

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

  When the content of the barium element in the negative electrode material is 3.0 mass% or less in terms of barium sulfate, the PSOC life performance is improved, so the content of the barium element in the negative electrode material is 3.0 mass% in terms of barium sulfate It is preferable to set it as the following. When the content of the barium element in the negative electrode material is 2.5 mass% or less in terms of barium sulfate, the PSOC life performance is greatly improved, so the content of the barium element in the negative electrode material is 2.5 mass in terms of barium sulfate It is more preferable to make it% or less.

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

  The barium sulfate in the negative electrode material preferably has, for example, an average secondary particle diameter of 1 to 10 μm. Moreover, it is preferable that the barium sulfate in negative electrode material has an average primary particle diameter of 0.3 to 2.0 μm, for example.

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

  When the content of the tin element in the positive electrode material is 0.01 mass% or more, the osmotic short circuit can be remarkably suppressed. Therefore, the content of the tin element in the positive electrode material is preferably 0.01 mass% or more. In addition, a metal, an oxide, a sulfate etc. can be considered as an existence form of the tin element in positive electrode material.

  Although the action mechanism by which the occurrence of the osmotic short circuit is suppressed by the addition of elemental tin to the positive electrode material is not necessarily clear, it is presumed as follows. Since the tin element has the effect of enhancing the conductivity, adding the tin element to the positive electrode material makes the charge / discharge reaction in the vertical direction of the positive electrode plate more uniform, and the concentration of the charging current on the top of the electrode plate is relaxed. Be done. When the concentration of the charging current on the upper part of the electrode plate is relaxed, the growth of dendritic lead at the upper part of the electrode plate is suppressed, and the synergetic effect is suppressed with the permeation shorting suppression effect by barium sulfate of 1.1 mass% or more in the negative electrode material. It is inferred that the occurrence of osmotic short circuit is remarkably suppressed.

  When the negative electrode material contains graphite or the like and at least 1.1 mass% of barium element in terms of barium sulfate, and the content of the 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 to the case where the element is not contained. Therefore, it is preferable to make content of the tin element in positive electrode material into 0.15 mass% or less. On the other hand, when the content of the barium element in the negative electrode material is not more than 1.0 mass% in terms of barium sulfate, the positive electrode material is made even if the content of the tin element in the positive electrode material is not more than 0.15 mass%. PSOC life performance does not improve as compared with the case where it does not contain a tin element. When the content of the barium element in the negative electrode material and the content of the tin element in the positive electrode material are in a specific range when the negative electrode material contains graphite or the like, the PSCO life performance is improved. Is unknown until now.

  When the negative electrode material contains graphite or the like and at least 1.1 mass% of a barium element in terms of barium sulfate, and the content of the tin element in the positive electrode material is 0.10 mass% or less, tin is used as the positive electrode material. PSOC life performance is greatly improved as compared to the case where no element is contained. Therefore, it is more preferable to make content of the tin element in positive electrode material into 0.10 mass% or less. When the negative electrode material contains graphite or the like and at least 1.1 mass% of a barium element in terms of barium sulfate, and the content of the tin element in the positive electrode material is 0.08 mass% or less, PSOC life performance is further increased. It is further preferable because it greatly improves. When the negative electrode material contains graphite or the like and at least 1.1 mass% of a barium element in terms of barium sulfate, and the content of the tin element in the positive electrode material is 0.06 mass% or less, PSOC life performance is particularly high. It is particularly preferable because it greatly improves.

  When the negative electrode material contains graphite or the like and at least 1.1 mass% of a barium element in terms of barium sulfate, and the content of the tin element in the positive electrode material is 0.03 mass% or more, tin is used as the positive electrode material. PSOC life performance is greatly improved as compared to the case where no element is contained. Therefore, it is preferable to make content of the tin element in positive electrode material into 0.03 mass% or more.

The improvement effect of PSOC life performance obtained when the negative electrode material contains graphite etc. and barium element of 1.1 mass% or more in terms of barium sulfate, and the positive electrode material contains 0.15 mass% or less of tin element The density increases when the density of the positive electrode material is 3.6 g / cm ³ or more. 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 the barium element in the negative electrode material is 1.0 mass% or less in terms of barium sulfate, the positive electrode material uses the tin element even when the density of the positive electrode material is 3.6 g / cm ³ or more. PSOC life performance does not improve as compared with the case where it does not contain.

The improvement effect of PSOC life performance obtained when the negative electrode material contains graphite etc. and barium element of 1.1 mass% or more in terms of barium sulfate, and the positive electrode material contains 0.15 mass% or less of tin element The density is further increased when the density of the positive electrode material is 4.2 g / cm ³ or more. 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 storage battery is improved, so the density of the positive electrode material is preferably 5.0 g / cm ³ or less.

  The lead storage battery according to one aspect of the present invention may further contain carbon black in the negative electrode material. When the negative electrode material contains graphite or the like and at least 1.1 mass% of a barium element in terms of barium sulfate, and the positive electrode material contains a tin element, when carbon black is further contained in the negative electrode material, permeation shorting occurs. Can be further suppressed. On the other hand, when the content of the 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 a tin element, carbon black is contained in the negative electrode material. However, the penetration shorting suppression effect by carbon black can not be obtained.

  It is preferable to set the content of carbon black in the negative electrode material to 0.1 mass% or more because permeation 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 material paste into the negative electrode current collector. Therefore, the content of carbon black in the negative electrode material is preferably 1.0 mass% or less.

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

<Negative electrode plate>
An 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 a reinforcing material such as graphite, carbon fiber, barium sulfate, carbon black, lignin as a pressure reducing agent, synthetic resin fiber, and the like. Instead of barium sulfate, barium alone or barium compounds such as barium carbonate may be used.

  The content of lignin is optionally, and in place of lignin, synthetic plasticizers such as condensates of sulfonated bisphenols may be used. The content of the reinforcing material and the type of the synthetic resin fiber are arbitrary. Moreover, the kind and manufacturing conditions of lead powder are arbitrary. Other additives, a water-soluble synthetic polymer electrolyte, etc. may be contained in the negative electrode material paste.

  After the negative electrode current collector is filled with the negative electrode material paste, aging and drying are performed to prepare an unformed negative electrode plate. For the negative electrode current collector, for example, an expanded grid, a cast grid, a punched grid, etc. can be used.

<Positive plate>
An unformed 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 a synthetic resin fiber, or the like. After this positive electrode material paste is filled in a positive electrode current collector, it is aged and dried to produce an unformed positive electrode plate. The type of lead powder and the manufacturing conditions are optional. Instead of tin sulfate, metal tin or the like may be used, and it is presumed that tin exists as a metal, an oxide, a sulfate compound or the like in the positive electrode material. The density of the positive electrode material after formation is adjusted by changing the amount of water added when producing the positive electrode material paste. For the positive electrode current collector, for example, an expanded grid, a cast grid, or a punched grid can be used.
<Lead storage battery>

  The lead storage battery can be manufactured as follows. An unformed negative electrode plate and an unformed positive electrode plate are alternately stacked via a separator, and the unformed negative electrode plates and the unformed positive electrode plates are respectively connected by straps to form an electrode plate group. It is accommodated in the cell chamber of a battery case in the state which connected the electrode group in series, a sulfuric acid is added and it is formed, and a lead storage battery is produced. After forming the unformed negative electrode plate and the unformed positive electrode plate, the electrode plate group may be assembled to produce a lead-acid battery. The separator is made of, for example, a synthetic resin, preferably made of polyolefin, and more preferably made of polyethylene. Also, the separator preferably has a rib projecting from the base. Although the base thickness of a separator, total thickness, etc. are arbitrary, 0.15 mm or more and 0.25 mm or less of the thickness of the base of a separator are preferable. 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. The separator may be formed into a bag shape, and the positive electrode plate or the negative electrode plate may be wrapped.

  FIG. 1 shows a main part of an electrode plate group 1 of a lead-acid battery according to an embodiment of the present invention, wherein 2 is a negative electrode plate, 3 is a positive electrode plate, and 4 is a separator. The negative electrode plate 2 comprises a negative electrode current collector 21 and a negative electrode material 22, and the positive electrode plate 3 comprises a positive electrode current collector 31 and a positive electrode material 32. The separator 4 has a bag shape including a base 41 and a rib 42. The negative electrode plate 2 is housed inside the bag, and the rib 42 faces the positive electrode plate 3 side. However, the positive electrode plate 3 may be housed in the separator 4 with the rib 42 facing the positive electrode plate 3, or the separator 4 may not have the rib 42. The separator does not have to be in the form of a bag as long as the separator separates the positive electrode plate and the negative electrode plate. For example, a leaflet-like glass mat or a retainer mat may be used.

  The content of the barium element contained in the negative electrode material after formation is quantified as follows. The fully charged lead-acid battery is disassembled, the negative electrode plate is washed with water and dried to remove sulfuric acid, and the negative electrode material is collected. The negative electrode material is crushed, and 300 g / L of hydrogen peroxide water is added at 20 mL per 100 g of the negative electrode material, and then nitric acid obtained by diluting 60 mass% of concentrated nitric acid with 3 volumes 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 formation are quantified as follows. The fully charged lead-acid battery is disassembled, the negative electrode plate is washed with water and dried to remove sulfuric acid, and the negative electrode material is collected. The negative electrode material is crushed, and 300 g / L of hydrogen peroxide water is added at 20 mL per 100 g of the negative electrode material, and then nitric acid obtained by diluting 60 mass% of concentrated nitric acid with 3 volumes of ion exchange water is added. Heat for 5 hours under stirring to dissolve lead as lead nitrate. Furthermore, the barium sulfate is dissolved. The resulting aqueous solution is filtered to separate solid components such as graphite, carbon black and reinforcing material.

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

  Carbon black and graphite are added to the negative electrode material paste together with an organic shrinkproofing agent such as lignin, and even in the negative electrode material after formation, carbon black and graphite are aggregates due to the surface activity effect of the organic shrinkproofing agent. It exists in a broken state. In the above series of separation operations, the organic anti-shrink agent is eluted in water and lost, and thus the separated carbon black and graphite are dispersed again in the water, and then, as an organic anti-shrink agent, Vanillex N, a lignin sulfonate, Nippon Paper Industries 15 g per 100 mL of water and stirred to carry out the following separation operation in a state where aggregates of carbon black and graphite are broken again.

  After the above operation, the suspension containing carbon black and graphite is sieved so that the carbon black can pass without substantially passing the graphite, and the two are separated. In this operation, the graphite remains on the sieve, and the liquid which has passed through the sieve contains carbon black. The weight of each of the graphite and carbon black separated by the above-mentioned series of operations is weighed after washing with water and drying. Carbon fibers are separated in the same manner as graphite, and weighed.

  The measuring method of the average particle diameter of graphite is shown below. As a measuring apparatus, a laser diffraction type particle size distribution measuring apparatus SALD 2200 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 the graphite is dispersed is irradiated with ultrasonic waves for 5 minutes using an ultrasonic cleaner. Next, the dispersion in which the 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, within the range in which the minimum is set to 0.1 μm and the maximum to 1000 μm, the particle diameter at which the cumulative volume is 50% (D50) is defined as the average particle diameter.

  The content of tin element in the positive electrode material after formation 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, 300 g / L of hydrogen peroxide water is added at 20 mL per 100 g of the positive electrode material, and then 60 mass% of concentrated nitric acid is diluted with three times its volume of ion exchanged water and nitric acid 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 fully charged positive electrode material after formation, and is measured as follows. The battery after formation is fully charged and then disassembled, and the obtained positive electrode plate is washed with water and dried to remove the electrolytic solution in the positive electrode plate. Next, the positive electrode material is separated from the positive electrode plate to obtain an uncrushed measurement sample. After charging the sample into the measurement container and evacuating, fill the mercury at a pressure of 0.5 to 0.55 psia, measure the bulk volume of the positive electrode material, and divide the mass of the measurement sample by the bulk volume. The bulk density of the positive electrode material is determined. In addition, let the volume which deducted the injection volume of mercury from the volume of the measurement container be a 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 partial charge state, and therefore is suitable for a lead storage battery used in a partial charge state such as lead storage battery for idling stop vehicles . Further, the lead storage battery according to the present embodiment is suitable for lead storage batteries for cycle applications such as for forklifts, in addition to lead storage batteries for idling stop vehicles. 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 embodiment, and can be implemented in various modifications and improvements in addition to the above embodiment. For example, the present invention can be implemented in the following manner.

  (1) A positive electrode plate, a negative electrode plate and an electrolytic solution are provided, and the negative electrode material of the negative electrode plate contains graphite or carbon fiber and at least 1.1 mass% of a barium element in terms of barium sulfate, and the positive electrode plate The positive electrode material of is a lead storage battery characterized by containing tin element.

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

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

  (4) The lead storage 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 acid battery according to any one of (1) to (6), wherein the graphite or carbon fiber is a graphite having an average particle diameter 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 a graphite having an average particle diameter of 100 μm or more.

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

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

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

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

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

  (17) The lead storage battery according to any one of (1) to (16), which contains the barium element as barium sulfate.

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

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

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

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

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

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

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

  (28) The lead storage 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 scale-like graphite or expanded graphite.

  (30) The lead storage battery according to any one of (1) to (29), wherein the graphite or carbon fiber is scale-like 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 storage battery according to any one of (1) to (31), wherein the lead storage battery is a liquid lead storage battery.

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

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

  (35) A vehicle equipped with the lead storage battery according to any one of (1) to (34).

  Examples are shown below. In the implementation, the embodiment can be appropriately modified in accordance with the common knowledge of the person skilled in the art and the disclosure of the 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.

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

  The prepared negative electrode active material paste is filled in an expanded type negative electrode grid (height 110 mm × width 100 mm × thickness 1.0 mm) made of Pb—Ca—Sn alloy not containing antimony, and subjected to aging and drying. An unformed negative electrode plate was produced.

Lead powder produced by the ball mill method is mixed with a predetermined amount of tin sulfate and a synthetic resin fiber (content: 0.1 mass%) of a 0.1 mass% reinforcing material, and paste made with water and sulfuric acid to make a positive electrode active A substance paste was made. The content of tin sulfate was changed in the range of 0 to 0.3 mass% in terms of metal tin. The prepared positive electrode active material paste is filled in an expanded positive electrode grid (height 110 mm × width 100 mm × thickness 1.2 mm) made of Pb—Ca—Sn alloy not containing antimony, and subjected to aging and drying. An unformed positive electrode plate was produced. In addition, the amount of water added at the time of forming a paste was changed to adjust the density of the positive electrode active material after formation to be 3.4 g / cm ³ or more and 5.0 g / cm ³ or less.

  The unformed negative electrode plate is wrapped with a polyethylene separator (average pore diameter: 0.1 μm) in which ribs protrude from the base, and seven unformed negative electrode plates and six unformed positive electrode plates are alternately laminated. The positive electrode plates were connected with each other by a strap to form an electrode plate group. In the example, 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 groups are connected in series and housed in the cell chamber of the battery case, sulfuric acid with a specific gravity of 1.285 is added at 20 ° C. to form a film in the battery case, and a B20 size for 5 hours rate capacity is 30 Ah Liquid lead-acid battery.

  The content of the barium element, the content of the graphite, the average particle diameter of the graphite, and the content of the carbon black contained in the negative electrode active material were measured as described above. A sieve with a diameter of 1.4 mm was used to separate carbon black and graphite in the negative electrode active material from the reinforcing material. After dispersing the separated carbon black and graphite in water, add lignin sulfonate, Vanillex N (manufactured by Nippon Paper Industries Co., Ltd.) as an organic shrink-proofing agent, and use a sieve with a diameter of 20 μm to carbon black and graphite separated. In addition, about the lead storage battery provided with the negative electrode plate with the same composition, one of those lead storage batteries was selected and measured, and the measurement result shall apply to all the lead storage batteries provided with the negative electrode plate of the same composition. Further, 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. For lead-acid batteries provided with positive electrode plates of the same composition, one of the lead-acid batteries was selected for measurement, and the measurement results were applied to all lead-acid batteries provided with positive electrode plates of the same composition.

  The PSOC life test and the permeation short circuit acceleration test were conducted on the fully charged lead-acid battery. The contents of the PSOC life test are shown in Table 1. One CA is 30 A for a battery with a nominal capacity of 30 Ah. “40 ° C. air” indicates that the test was performed in a 40 ° C. air tank. The contents of PSOC life test are as follows. First, a constant current discharge (step 1) for 59 seconds at 1 CA and a constant current discharge (step 2) for 1 second at 300 A are performed. Next, constant-voltage charging (step 3) for 10 seconds at a voltage of 2.4 V per cell (charge current is 50 A at maximum) and constant-current discharge for 5 seconds at 1 CA (step 4). Steps 3 and 4 are repeated a total of five times (Step 5), and Steps 1 to 5 are repeated a total of 50 times (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 (charging current is 50 A at maximum). Steps 1 to 7 are repeated 72 times in total (Step 8), and after a rest of 15 hours (Step 9), return 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 taken as the PSOC lifetime number. In addition, one cycle is set in steps 1 to 5. For example, when steps 1 to 10 are performed once, the number of cycles is 3600 cycles.

  The contents of the permeation short circuit accelerated test are shown in Table 2. This test is conducted under conditions that promote the occurrence of osmotic short circuit, and the incidence rate of osmotic short circuit is significantly higher than the actual use condition of lead storage battery. The contents of the penetration short circuit promotion test are as follows. First, constant current discharge is performed at 0.05 CA until the voltage per cell becomes 1.0 V (step 1). Next, a 10 Ω resistor is connected between the positive electrode terminal and the negative electrode terminal of the lead storage battery, and left in this state for 23 hours and 50 minutes (step 2). Thereafter, constant voltage charging (charging current is 50 A at maximum) is performed for 10 minutes at a voltage of 2.4 V per cell (step 3). After repeating steps 2 and 3 a total of 5 times (step 4), the lead storage battery was disassembled, and the proportion of the lead storage battery in which the short occurred was examined. In addition, "25 degreeC water" shows having tested in a 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 permeation short circuit acceleration test. In Tables 3 to 10, the PSOC life count indicates the ratio of the PSOC life count of each battery when the PSOC life count of the battery A1 in Table 3 is 100. PSOC life ratio represents the ratio of the number of PSOC lifetimes of each battery to the number of PSOC lifetimes of the first battery in each table.

  It can be seen from Table 5 and FIG. 2 that in the lead storage battery containing graphite in the negative electrode active material, the PSOC life performance is improved compared to the lead storage battery under the same conditions except for the content of graphite. When 0.5 mass% or more of graphite is contained in the negative electrode active material, PSOC life performance is greatly improved, and when 1.0 mass% or more of graphite is contained in the negative electrode active material, PSOC life performance is further greatly improved.

  On the other hand, it can be seen from Tables 3 to 6 and FIG. 2 that in the lead storage battery containing graphite in the negative electrode active material, permeation short circuit is more likely to occur in the lead storage battery under the same conditions except for the graphite content. Thus, it has not been known until now that penetration short circuit easily occurs when graphite is contained in the negative electrode active material.

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

  According to Tables 3 to 6 and FIG. 4, when the content of the 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 the tin element to largely suppress the osmotic short circuit. I know what I can do. When the content of the tin element in the positive electrode active material is 0.01 mass% or more, the osmotic short circuit can be significantly suppressed. On the other hand, when the content of the 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 the tin element, the penetration short circuit suppression effect by the tin element can not be obtained .

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

  From Table 3 to Table 6 and FIG. 5, when the content of the barium element in the negative electrode active material is 1.1 mass% or more in terms of barium sulfate, the content of the tin element in the positive electrode active material is 0.15 mass% or less By setting it, it turns out that PSOC lifetime performance improves compared with the case where a positive electrode active material does not contain a tin element. When the content of tin element in the positive electrode active material is 0.10 mass% or less, PSOC life performance is greatly improved, and when the content of tin element in the positive electrode active material is 0.08 mass% or less, PSOC life performance is The performance is further greatly improved, and when the content of tin element in the positive electrode active material is 0.06 mass% or less, the PSOC life performance is particularly greatly improved. On the other hand, in the case where the content of the barium element in the negative electrode active material is 1.0 mass% or less in terms of barium sulfate, the positive electrode active material is obtained even if the content of the tin element in the positive electrode active material is 0.15 mass% or less The PSOC life performance is not improved as compared to the case of not containing tin element.

  When the content of the barium element in the negative electrode material and the content of the tin element in the positive electrode material are in a specific range when the negative electrode material contains graphite etc., the PSOC life performance is improved. Is an unknown result that has never been known.

From Tables 3 to 6 and FIG. 6, the negative electrode active material contains graphite and at least 1.1 mass% of a barium element in terms of barium sulfate, and the positive electrode active material contains at most 0.15 mass% of a tin element. It can be seen that the improvement effect of 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 improvement effect of PSOC life performance is further large, and when the density of the positive electrode active material is 4.4 g / cm ³ or more, the improvement effect of PSOC life performance Becomes significantly larger. On the other hand, when the content of the barium element in the negative electrode active material is 1.0 mass% or less in terms of barium sulfate, PSOC life performance does not improve 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 the PSOC life performance is improved when the content of the barium element in the negative electrode active material is 3.0 mass% or less in terms of barium sulfate.

  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 graphite and barium element at 1.1 mass% or more in terms of barium sulfate and the positive electrode active material contains a tin element, carbon black is contained in the negative electrode active material. It can be seen that the osmotic short circuit can be further suppressed. When the carbon black content in the negative electrode active material is 0.1 mass% or more, the osmotic short circuit can be largely suppressed. On the other hand, when the content of the 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 a tin element, the penetration shorting suppression effect by carbon black can not be obtained .

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

  Tables 9 and 10 show the results of the case where expanded graphite is contained in the negative electrode active material instead of flake graphite. From Tables 9 and 10, it can be seen that similar results can be obtained by using expanded graphite instead of flake graphite.

  In the embodiment, a liquid lead-acid battery with less permeation short circuit is obtained, but the separator may be a glass mat or the like and may be a control valve-type lead-acid battery.

  The present invention can provide a lead-acid battery in which PSOC life performance is improved and the occurrence of osmotic short circuit can be suppressed. Therefore, the present invention is useful for IS vehicles and the like which are often placed in a state of insufficient charge.

DESCRIPTION OF SYMBOLS 1 Lead-acid battery electrode plate group 2 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 (15)

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 at least 1.1 mass% of a barium element in terms of barium sulfate,
The lead storage battery characterized in that a positive electrode material of the positive electrode plate contains a tin element.   The lead storage battery according to claim 1, wherein the positive electrode material contains 0.15 mass% or less of a tin element. The lead storage battery according to claim 1, wherein the density of the positive electrode material is 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.   The lead storage battery according to any one of claims 1 to 6, wherein the graphite or carbon fiber is a graphite having an average particle diameter of 300 μm or less.   The lead storage battery according to any one of claims 1 to 7, wherein the graphite or carbon fiber is a 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 3.0 mass% or less of a barium element in terms of barium sulfate.   The lead storage battery according to any one of claims 1 to 9, wherein the positive electrode material contains 0.01 mass% or more of tin element. 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 10. Wherein the density of the positive electrode material is 5.0 g / cm ³ or less, a lead acid battery according to any one of claims 1 to 11.   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.   The lead acid battery according to any one of claims 1 to 13, wherein the lead acid battery is a liquid lead acid battery.   The vehicle carrying the lead storage battery in any one of Claims 1-14.