JP2017183160A - Lead storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead storage battery which improves charge acceptability and has excellent lifespan performance and low temperature high rate discharge characteristics.SOLUTION: The lead storage battery includes a positive electrode plate and a negative electrode plate facing each other with a separator interposed therebetween and an electrolyte. The positive electrode plate includes a positive electrode material and the negative electrode plate includes a negative electrode material. The specific surface area of the positive electrode material is 10 m/g or more, and the positive electrode material contains tin oxide.SELECTED DRAWING: None

Description

  The present invention relates to a lead-acid battery.

  In recent years, various measures for improving fuel efficiency have been studied for automobiles in order to prevent air pollution or global warming. Examples of automobiles with measures to improve fuel efficiency include micro hybrids such as idling stop system cars (hereinafter referred to as “ISS cars”) that reduce engine operation time, and power generation control cars that use engine rotation for power without waste. Cars are being considered.

  In an ISS vehicle, the number of engine starts increases, so that a large current discharge of the lead storage battery is repeated. Further, in the ISS car and the power generation control car, the amount of power generated by the alternator is reduced, and the lead storage battery is charged intermittently, so that the charge is insufficient.

  The lead storage battery which is used as described above is used in a partially charged state called PSOC (Partial State Of Charge). Lead acid batteries have a shorter life when used under PSOC than when used in a fully charged state.

  In recent years, in Europe, the chargeability of lead-acid batteries during charge / discharge cycles in accordance with the control of micro hybrid vehicles has been regarded as important, and DCA (Dynamic Charge Acceptance) evaluation in this form is being standardized. is there. In other words, the use of the lead storage battery as described above has been regarded as important.

  On the other hand, Patent Document 1 below discloses a technique that uses a positive electrode active material having a specific surface area in order to improve the charging efficiency and life performance of a battery when used under PSOC.

International Publication No. 2012/042917

  By the way, when a lead-acid battery is used in a state where charging is not complete and charging is insufficient, the concentration of dilute sulfuric acid, which is an electrolytic solution, between the upper part and the lower part of the electrodes (electrode plates, etc.) A stratification phenomenon occurs where a difference occurs. In this case, the concentration of dilute sulfuric acid in the lower part of the electrode becomes high and sulfation occurs. Therefore, the reactivity of the lower part of the electrode is lowered, and only the upper part of the electrode reacts intensively. As a result, the deterioration such as weakening of the connection between the active materials proceeds, and the active material is peeled from the lattice at the upper part of the electrode, leading to a decrease in battery performance and an early life.

  Therefore, in recent micro hybrid vehicle lead-acid batteries, it is an extremely important issue to improve charge acceptability in order to improve battery life performance when used under PSOC.

On the other hand, Patent Document 1 describes that the specific surface area of the positive electrode active material is adjusted to 5.5 m ² / g or more by changing the conditions for forming the battery case. However, it has been found that simply changing the conditions for forming the battery case has a limit in increasing the specific surface area of the positive electrode active material, and it is difficult to further improve the charge acceptability.

  Furthermore, since the high rate discharge characteristics of the lead storage battery are required under low temperature conditions where it is difficult to start the engine, it is also important to improve the low temperature high rate discharge characteristics of the lead storage battery.

  This invention is made | formed in view of the said situation, Furthermore, it aims at providing a lead storage battery which improves charge acceptance property and is excellent in lifetime performance and a low-temperature high-rate discharge characteristic.

The lead storage battery according to the present invention is a lead storage battery including a positive electrode plate and a negative electrode plate facing each other with a separator interposed therebetween, and an electrolyte solution, wherein the positive electrode plate includes a positive electrode material, and the negative electrode plate includes a negative electrode material, The specific surface area of a positive electrode material is 10 m < ² > / g or more, The said positive electrode material is a lead acid battery containing a tin oxide. According to the lead storage battery according to the present invention, it is possible to obtain a lead storage battery with improved charge acceptability and excellent life performance.

From the viewpoint of further improving the chargeability, the positive electrode material comprises a beta-PbO ₂ and _{α-PbO 2, β-PbO} 2 and alpha-PbO ₂ in the ratio of the peak intensity of X-ray diffraction pattern (alpha-PbO ₂ / β-PbO ₂ ) is preferably 0.4 or less.

  From the viewpoint of further improving the life performance, the positive electrode material preferably contains antimony oxide.

  From the standpoint that sufficient battery capacity is easily obtained and high charge acceptance is easily obtained, the mass ratio of the positive electrode material to the negative electrode material (positive electrode material / negative electrode material) is 1.05 or more. preferable.

  According to the lead storage battery of the present invention, it is possible to obtain excellent charge acceptance. Moreover, according to the lead acid battery which concerns on this invention, charge acceptability can be improved and the outstanding cycling characteristics can be acquired. The lead acid battery according to the present invention is excellent in low temperature and high rate discharge characteristics. The lead storage battery according to the present invention can be suitably used in a micro hybrid vehicle such as an ISS vehicle as a liquid lead storage battery in which charging is intermittently performed and high rate discharge to the negative electrode is performed under PSOC.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, since specific gravity changes with temperature, in this specification, it defines as specific gravity converted at 20 degreeC.

The lead storage battery according to the present embodiment is a lead storage battery including a positive electrode plate and a negative electrode plate facing each other with a separator interposed therebetween, and an electrolyte solution, wherein the positive electrode plate includes a positive electrode material, and the negative electrode plate includes a negative electrode material, The positive electrode material has a specific surface area of 10 m ² / g or more, and the positive electrode material is a lead storage battery containing tin oxide.

  According to the lead storage battery of the present invention, it is possible to obtain excellent charge acceptance. Therefore, in particular, after the charge and discharge are repeated to some extent from the initial state and the active material is sufficiently activated, the SOC that tends to be low in the micro hybrid vehicle can be maintained at an appropriate level. According to the present invention, it is possible to obtain a lead storage battery with improved charge acceptability and excellent life performance.

<Lead battery>
The lead storage battery according to the present embodiment includes, for example, an electrode (electrode plate or the like), an electrolytic solution (sulfuric acid or the like), and a separator. The electrode has a positive electrode (positive electrode plate or the like) and a negative electrode (negative electrode plate or the like). Examples of the lead storage battery according to this embodiment include a liquid lead storage battery, a control valve type lead storage battery, a sealed lead storage battery, and the like, and a liquid lead storage battery is preferable. The positive electrode has a current collector (positive electrode current collector) and a positive electrode material held by the current collector. The negative electrode has a current collector (negative electrode current collector) and a negative electrode material held by the current collector. In the present embodiment, the positive electrode material and the negative electrode material are, for example, electrode materials after chemical conversion (for example, in a fully charged state). When the electrode material is unformed, the electrode material (unformed positive electrode material and unformed negative electrode material) contains a raw material of an electrode active material (positive electrode active material and negative electrode active material) and the like. The current collector constitutes a conductive path for current from the electrode material. A configuration similar to that of a conventional lead-acid battery can be used.

(Positive electrode material)
The positive electrode material contains a positive electrode active material. The positive electrode material can be obtained by chemical conversion after obtaining an unformed active material by aging and drying a positive electrode material paste containing a raw material for the positive electrode active material. The positive electrode material after chemical conversion preferably contains β-lead dioxide (β-PbO ₂ ), and may further contain α-lead dioxide (α-PbO ₂ ). There is no restriction | limiting in particular as a raw material of a positive electrode active material, For example, lead powder is mentioned. As the lead powder, for example, lead powder manufactured by a ball mill type lead powder manufacturing machine or a Burton pot type lead powder manufacturing machine (in the ball mill type lead powder manufacturing machine, a mixture of powder of the main component PbO and scale-like metal lead) Is mentioned. Red lead (Pb ₃ O ₄ ) may be used as a raw material for the positive electrode active material. The unformed positive electrode material preferably contains an unformed positive electrode active material containing tribasic lead sulfate as a main component.

The ratio of the peak intensities of the X-ray diffraction patterns of β-PbO ₂ and α-PbO ₂ (α-PbO ₂ / β-PbO ₂ ) in the positive electrode material after chemical conversion is from the viewpoint of obtaining excellent charge acceptance. 4 or less is preferable. When the ratio α-PbO ₂ / β-PbO ₂ is 0.4 or less, the overvoltage of the positive electrode can be lowered, so that it is estimated that excellent charge acceptability can be obtained. The ratio α-PbO ₂ / β-PbO ₂ is more preferably 0.3 or less, still more preferably 0.2 or less, and even more preferably 0.06 or less, from the viewpoint of obtaining further excellent charge acceptance. The ratio α-PbO ₂ / β-PbO ₂ may be 0.05 or less, 0.04 or less, or 0.03 or less. The ratio α-PbO ₂ / β-PbO ₂ is preferably 0.005 or more, more preferably 0.01 or more, and still more preferably 0.02 or more, from the viewpoint of excellent shape retention of the positive electrode material. The ratio α-PbO ₂ / β-PbO ₂ can be adjusted by, for example, the temperature at the time of chemical formation. For example, the α-PbO ₂ ratio can be increased as the formation temperature increases.

For example, α-PbO ₂ , β-PbO ₂ , and PbSO ₄ are detected as main compounds from the wide-angle X-ray diffraction measurement of the preformed positive electrode active material of the positive electrode. Using the main peak intensities (cps) of the waveforms specified as the respective compounds of α-PbO ₂ and β-PbO ₂ , “α-PbO ₂ main peak intensity” / “β-PbO ₂ main peak intensity” The ratio can be calculated as the ratio α-PbO ₂ / β-PbO ₂ . As the wide-angle X-ray diffractometer, for example, an X-ray diffractometer SmartLab (manufactured by Rigaku) can be used.

Wide-angle X-ray diffraction measurement can be performed, for example, by the following method.
[Wide-angle X-ray diffraction measurement method]
-Measuring device: Fully automatic multipurpose horizontal X-ray diffractometer SmartLab (manufactured by Rigaku Corporation)
・ X-ray source: Cu-Kα / 1.541862Å
・ Filter: Cu-Kβ
・ Output: 40kV, 30mA
・ Scan mode: CONTINUOUS
Scan range: 20.0000 degrees to 60.000 degrees Step width: 0.0200 degrees Scan axis: 2θ / θ
・ Scanning speed: 10.0000 degrees / min ・ Sample holder: Glass, depth 0.2mm
Sample preparation method: The measurement sample can be prepared by the following procedure. First, the formed battery is disassembled, the positive electrode (positive electrode plate or the like) is taken out, washed with water, and dried at 50 ° C. for 24 hours. Next, 3 g of the positive electrode material is collected from the center of the positive electrode and ground.

Calculation method: Fill the positive electrode material so that the thickness of the positive electrode material is equal to the depth of the sample holder, and produce a smooth sample surface. Wide-angle X-ray diffraction is measured to obtain an X-ray diffraction pattern (X-ray diffraction chart) of diffraction angle (2θ) and diffraction peak intensity. In the X-ray diffraction pattern, for example, α-PbO ₂ positioned at a diffraction angle of 28.6 degrees and β-PbO ₂ positioned at a diffraction angle of 25.3 degrees are detected. Using the peak intensity (cps) of the waveform specified as each compound of α-PbO ₂ (110 face) and β-PbO ₂ (111 face), “peak intensity of α-PbO ₂ ” / “β-PbO ₂ Is calculated as a ratio α-PbO ₂ / β-PbO ₂ .

The positive electrode material contains tin oxide. In this invention, it discovered that lifetime performance improved because the positive electrode material contains a tin oxide. Examples of tin oxide include tin dioxide (SnO ₂ ). Generally, since lead sulfate generated at the time of discharge is an insulator, it is thought that subsequent conductivity is impaired when lead sulfate accumulates on the positive electrode plate. The reason why the life performance is improved is presumed to be that the presence of strong sulfuric acid dilute sulfuric acid and tin oxide that is stable in an oxidizing atmosphere in the positive electrode material can maintain conductivity. The

From the viewpoint of further improving the life performance, it is preferable that the positive electrode material contains an antimony oxide. Examples of the antimony oxide include diantimony pentoxide (Sb ₂ O ₅ ).

The specific surface area of the positive electrode material of the lead storage battery according to the present invention is 10 m ² / g or more from the viewpoint of improving charge acceptance. The specific surface area of the positive electrode material is more preferably 12 m ² / g or more, more preferably 11 m ² / g or more from the viewpoint of further improving charge acceptance. Although there is no limit to the upper limit of the specific surface area of the cathode material, from the viewpoint of practical aspects and utilization, is preferably from 20 m ² / g, more preferably not more than 15 m ² / g, more preferably 13m ² / g or less. The specific surface area of the positive electrode material is, for example, a method of adjusting the amount of sulfuric acid and water added when preparing a positive electrode active material paste, which will be described later, a method of refining the active material in the unformed stage, and a method of changing the conversion conditions Etc. can be adjusted.

  The specific surface area of the positive electrode material can be measured by, for example, the BET method. The BET method is a method in which an inert gas (for example, nitrogen gas) having a known molecular size is adsorbed on the surface of a measurement sample, and the surface area is obtained from the adsorption amount and the area occupied by the inert gas. This is a general method for measuring the surface area. Specifically, it is measured based on the following BET equation.

Relationship of the following formula (1), P / P _o is established well in the range of 0.05 to 0.35. In addition, in Formula (1), the detail of each code | symbol is as follows.

P: adsorption equilibrium pressure P _o when an adsorption equilibrium state at a constant temperature: the saturated vapor pressure at the adsorption temperature V: adsorption equilibrium pressure adsorption amount of P V _m: monomolecular monolayer adsorption amount (gas molecules solid surface Adsorption amount when layer is formed)
C: BET constant (parameter relating to the interaction between the solid surface and the adsorbent)

By transforming equation (1) (dividing the numerator denominator on the left side by P), the following equation (2) is obtained. In the specific surface area meter used for the measurement, gas molecules whose adsorption occupation area is known are adsorbed on the sample, and the relationship between the adsorption amount (V) and the relative pressure (P / P _o ) is measured. From the measured V and P / _Po , the left side of Equation (2) and P / _Po are plotted. Here, assuming that the gradient is s, the following formula (3) is derived from the formula (2). Assuming that the intercept is i, the intercept i and the gradient s are as shown in the following formulas (4) and (5), respectively.

When the equations (4) and (5) are modified, the following equations (6) and (7) are obtained, respectively, and the following equation (8) for obtaining the monomolecular layer adsorption amount V _m is obtained. That is, when the adsorption amount V at a certain relative pressure P / _Po is measured at several points and the slope and intercept of the plot are obtained, the monomolecular layer adsorption amount V _m is obtained.

The total surface area S _total (m ² ) of the sample is determined by the following formula (9), and the specific surface area S (m ² / g) is determined by the following formula (10) from the total surface area S _total . In the formula (9), N represents the Avogadro number, A _CS represents the adsorption cross section (m ² ), and M represents the molecular weight. Moreover, in Formula (10), w shows a sample amount (g).

  In the positive electrode manufacturing process, for example, a positive electrode material paste is filled in a current collector (for example, a current collector grid) and then aged and dried to obtain a positive electrode having an unformed positive electrode active material. The unformed positive electrode active material preferably includes an unformed positive electrode active material containing tribasic lead sulfate as a main component. The positive electrode material paste includes, for example, a raw material for the positive electrode active material, and may further include other predetermined additives.

  Examples of the method of including the tin oxide in the positive electrode material include a method of mixing as a tin oxide powder or a tin oxide raw material dispersant when preparing a positive electrode material paste.

  As a raw material of tin oxide, for example, an organic tin compound such as dibutyltin diacetate or tributoxytin, or an inorganic tin compound such as tin tetrachloride is used, and as a solvent, an organic solvent such as ethanol or butanol is used. It is done.

  Examples of the additive contained in the positive electrode material paste include barium sulfate, a carbon active material, and reinforcing short fibers (acrylic fiber, polyethylene fiber, polypropylene fiber, polyethylene terephthalate fiber, carbon fiber, and the like). Examples of the carbon active material material include carbon black and graphite. Examples of carbon black include furnace black, channel black, acetylene black, thermal black, and ketjen black.

In producing the positive electrode material paste, lead powder can be used as a raw material for the positive electrode active material. From the viewpoint of shortening the chemical conversion time, lead (Pb ₃ O ₄ ) may be added as a raw material for the positive electrode active material. A positive electrode having an unformed positive electrode active material is obtained by filling the positive electrode active material paste into a current collector (eg, current collector grid) and then aging and drying. In the positive electrode active material paste, the blending amount of the reinforcing short fibers is preferably 0.005 to 0.3% by mass based on the total mass of the raw material of the positive electrode active material.
The positive electrode material can be obtained by chemical conversion after obtaining an unformed positive electrode active material by aging and drying a positive electrode material paste containing a raw material for the positive electrode active material. The positive electrode material after the formation includes, for example, α-PbO ₂ and β-PbO ₂ .

  Examples of the composition of the current collector include lead alloys such as a lead-calcium-tin alloy and a lead-antimony-arsenic alloy. Depending on the application, selenium, silver, bismuth or the like may be added to the current collector. A current collector can be obtained by forming these lead alloys in a lattice shape by a gravity casting method, an expanding method, a punching method, or the like.

(Negative electrode material)
The negative electrode material can be obtained by chemical conversion after obtaining an unformed active material by aging and drying a negative electrode material paste containing a raw material of the negative electrode active material. Examples of the negative electrode active material after chemical conversion include spongy lead. The spongy lead tends to react with sulfuric acid in the electrolyte and gradually change to lead sulfate (PbSO ₄ ). Examples of the raw material for the negative electrode active material include lead powder. As the lead powder, for example, lead powder manufactured by a ball mill type lead powder manufacturing machine or a Burton pot type lead powder manufacturing machine (in the ball mill type lead powder manufacturing machine, a mixture of powder of the main component PbO and scale-like metal lead) Is mentioned. The unformed negative electrode material is composed of, for example, basic lead sulfate, metallic lead, and a lower oxide.

The specific surface area of the negative electrode material is preferably 0.4 m ² / g or more, more preferably 0.5 m ² / g or more, and 0.6 m ² / g or more from the viewpoint of increasing the reactivity between the electrolytic solution and the negative electrode active material. Is more preferable. The specific surface area of the negative electrode material, from the further suppression of the contraction of the negative electrode at the time of the cycle is preferably not more than 2m ² / g, more preferably not more than 1.8 m ² / g, more preferably not more than 1.5 m ² / g. The specific surface area of the negative electrode material can be adjusted by, for example, a method of refining the active material in an unformed stage. The specific surface area of the negative electrode material can be measured by, for example, the BET method in the same manner as the positive electrode material.

  In the negative electrode manufacturing process, for example, a negative electrode material paste is filled in a current collector (for example, a current collector grid) and then aged and dried to obtain a negative electrode having an unformed negative electrode active material. As the current collector for the negative electrode, the same current collector as that for the positive electrode can be used. The unformed negative electrode active material preferably contains an unformed negative electrode active material containing tribasic lead sulfate as a main component. The negative electrode active material paste includes, for example, a raw material for the negative electrode active material, and may further include other predetermined additives.

  The negative electrode material paste may further contain a solvent and sulfuric acid. As a solvent, water (for example, ion-exchange water) and an organic solvent are mentioned, for example.

  Examples of the additive contained in the negative electrode material paste include barium sulfate, a carbon active material, and reinforcing short fibers (acrylic fiber, polyethylene fiber, polypropylene fiber, polyethylene terephthalate fiber, carbon fiber, and the like). Examples of the carbon active material material include carbon black and graphite. Examples of carbon black include furnace black, channel black, acetylene black, thermal black, and ketjen black.

  The negative electrode material paste can be obtained, for example, by the following method. First, a mixture is obtained by mixing a resin having a sulfo group and an additive that is added as necessary to lead powder. Next, a negative electrode material paste is obtained by adding sulfuric acid (such as dilute sulfuric acid) and a solvent (such as water) to this mixture and kneading.

<Method for producing lead-acid battery>
As a lead acid battery concerning this embodiment, a liquid lead acid battery and a sealed lead acid battery are mentioned, for example, and a liquid lead acid battery is preferred. The lead acid battery manufacturing method according to the present embodiment includes, for example, an electrode manufacturing process for obtaining electrodes (positive electrode and negative electrode), and an assembling process for assembling a component active material including the electrodes to obtain a lead acid battery. When the electrode is not formed, the electrode includes, for example, an electrode active material containing a raw material for the electrode active material and a current collector that holds the electrode active material. The electrode after the formation includes, for example, an electrode active material containing an electrode active material and the like, and a current collector that serves as a current conduction path from the electrode active material and holds the electrode active material.

  In the method for producing a lead-acid battery, for example, the negative electrode and the positive electrode produced as described above are laminated via a separator, and the current collector of the same polarity electrode plate is welded with a strap to obtain an electrode plate group. This electrode group is arranged in a battery case to produce an unformed battery. Next, dilute sulfuric acid is put into an unformed battery, and a direct current is applied to form a battery case. The lead acid battery can be obtained by adjusting the specific gravity (converted to 20 ° C.) of the sulfuric acid after the formation to an appropriate specific gravity of the electrolyte. Sulfuric acid specific gravity (20 degreeC conversion) used for chemical conversion has preferable 1.20-1.25. The sulfuric acid specific gravity after conversion (20 ° C. conversion) is preferably 1.26 to 1.30.

  The chemical conversion conditions and the specific gravity of sulfuric acid can be adjusted according to the size of the electrode. Further, the chemical conversion treatment is not limited to being performed after the assembly process, and may be performed in the electrode manufacturing process (tank chemical conversion).

  The battery case accommodates an electrode plate therein, and preferably has a box body whose upper surface is opened and a lid body that covers the upper surface of the box body from the viewpoint of ease of accommodating the electrode plate. Can be used for Note that an adhesive, heat welding, laser welding, ultrasonic welding, or the like can be appropriately used for bonding the box and the lid.

  The shape of the battery case is not particularly limited, but since the electrode plate is usually a plate-like body, it is preferable to use a rectangular one so that the ineffective space is reduced when the electrode plate is stored.

  The material of the battery case is not particularly limited, but it needs to be resistant to an electrolytic solution (dilute sulfuric acid, etc.). Specifically, PP, PE, ABS, etc. can be used. , PP is advantageous in terms of acid resistance, processability (difficult to heat weld the battery case and lid with ABS), and cost.

  In addition, when the battery case is formed of the box body and the lid body described above, the box body and the lid body may be formed of different active material materials, or may be formed of the same active material material. However, it is preferable to use ones having the same thermal expansion coefficient because no excessive stress is generated.

  The mass ratio of the positive electrode material to the negative electrode material (positive electrode material / negative electrode material) is preferably 0.9 or more, more preferably 1 or more, from the viewpoint that sufficient battery capacity is easily obtained and high charge acceptability is easily obtained. 1.05 or more is still more preferable. The mass ratio of the positive electrode material to the negative electrode material is preferably 1.3 or less, more preferably 1.2 or less, and even more preferably 1.15 or less, from the viewpoint that a sufficient battery capacity can be easily obtained. The mass ratio of the positive electrode material to the negative electrode material is preferably 0.9 to 1.3, more preferably 1 to 1.2, from the viewpoint that sufficient battery capacity is easily obtained and high charge acceptability is easily obtained. 0.05 to 1.15 is more preferable. The said mass ratio of the positive electrode material with respect to a negative electrode material is a mass ratio of the negative electrode material and positive electrode material after chemical conversion. The mass of the positive electrode material and the negative electrode material after conversion is determined by separating the grid, the positive electrode material, and the negative electrode material from the electrode plate by washing the formed electrode plate with water and washing away water-soluble components such as sulfuric acid. It can be measured.

Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited to the following examples.
<Example 1>
(Preparation of positive electrode plate)
0.23% by mass of acrylic fiber and 0.02% by mass of sodium sulfate were added to the lead powder as a reinforcing short fiber and dry mixed. Next, with respect to the lead powder, 0.5% by mass and water of 1.7% antimony and 15.3% tin dioxide in water (Mitsubishi Materials Electronics Chemicals Co., Ltd .; antimony doped water dispersant TDL-1) as a solid content 8% by mass was added and kneaded to prepare paste A.

Next, 14.6% by mass of dilute sulfuric acid (specific gravity 1.28) was added to kneaded lead (Pb ₃ O ₄ ) and kneaded to prepare paste B.

  The paste B was added to the paste A and kneaded for 1 hour to prepare a positive electrode active material paste. In this positive electrode active material paste, the amount of paste B added is adjusted so that the ratio of the lead powder contained in paste A and the lead powder contained in paste B is lead powder / lead powder = 85/15. did. Further, the total amount of water was 8% by mass with respect to the total amount of lead powder and red lead. In preparing the positive electrode active material paste, dilute sulfuric acid was added step by step to avoid a rapid temperature rise.

  An expanded current collector produced by subjecting a rolled sheet made of a lead alloy to expansion processing was filled with the positive electrode active material paste, and then aged for 24 hours in an atmosphere of a temperature of 50 ° C. and a humidity of 98%. Then, it dried at the temperature of 50 degreeC for 16 hours, and produced the positive electrode plate which has a non-chemically formed positive electrode active material.

(Preparation of negative electrode plate)
Lead powder was used as a raw material for the negative electrode active material. Bispazu P215 (condensate of bisphenol, aminobenzenesulfonic acid and formaldehyde, trade name, manufactured by Nippon Paper Industries Co., Ltd.) 0.2% by mass (resin solid content), reinforcing short fiber (acrylic fiber) 0.1% by mass, sulfuric acid A mixture of 1.0% by mass of barium and 0.2% by mass of carbonaceous conductive active material (furnace black) was added to the lead powder and then dry-mixed (the compounding amount is the total mass of the raw material of the negative electrode active material) The blending amount is based on Next, the mixture was kneaded after adding water. Subsequently, the mixture was kneaded while dilute sulfuric acid having a specific gravity of 1.280 was added little by little to prepare a negative electrode active material paste. The negative electrode active material paste was filled in an expandable current collector produced by subjecting a rolled sheet made of a lead alloy to an expanding process, and then aged for 24 hours in an atmosphere of a temperature of 50 ° C. and a humidity of 98%. Thereafter, drying was performed to prepare a negative electrode plate having an unformed negative electrode active material.

(Battery assembly)
An unformed negative electrode plate was inserted into a polyethylene separator processed into a bag shape. Next, five unformed positive electrode plates and six unformed negative electrode plates inserted in the bag-like separator were alternately laminated. Then, the electrode plate group was prepared by welding the ears of the same polarity electrode plates by a cast on strap (COS) method. The electrode plate group was inserted into a battery case to assemble a 2V single cell battery (corresponding to a K42 size single cell defined in JIS D 5301). Thereafter, a sulfuric acid solution having a specific gravity of 1.230 was injected, and chemical conversion was performed at a constant current of 10.4 A for 20 hours.

(Measurement of specific surface area)
The specific surface areas of the positive electrode active material and the negative electrode active material after chemical conversion were measured according to the BET method by measuring the nitrogen gas adsorption amount at the liquid nitrogen temperature while cooling the sample with liquid nitrogen and by the multipoint method. The measurement conditions are as follows. As a result of the measurement, the specific surface area of the positive electrode active material was 10.0 m ² / g. Further, the specific surface area of the negative electrode active material was 0.6 m ² / g.
[Specific surface area measurement conditions]
Apparatus: Macsorb 1201 (Moontech Co., Ltd.)
Degassing time: 10 minutes at 130 ° C. Cooling: 5 minutes with liquid nitrogen Adsorbed gas flow rate: 25 mL / min (measurement of α-PbO ₂ / β-PbO ₂ ratio based on peak intensity of X-ray diffraction pattern)
The measurement sample was produced by the following procedure. First, the formed battery was disassembled, the positive electrode plate was taken out, washed with water, and then dried at 50 ° C. for 24 hours. Next, 3 g of the positive electrode material was collected from the center of the positive electrode plate and ground. Subsequently, the positive electrode material was filled in the sample holder so that the thickness of the positive electrode material was equal to the depth of the sample holder to produce a smooth sample surface, and then measurement was performed. An apparatus for measuring the α-PbO ₂ / β-PbO ₂ ratio, measurement conditions, calculation method, and the like are described below.

-Measuring device: Fully automatic multipurpose horizontal X-ray diffractometer SmartLab (manufactured by Rigaku Corporation)
・ X-ray source: Cu-Kα / 1.541862Å
・ Filter: Cu-Kβ
・ Output: 40kV, 30mA
・ Scan mode: CONTINUOUS
Scan range: 20.0000 degrees to 60.000 degrees Step width: 0.0200 degrees Scan axis: 2θ / θ
・ Scanning speed: 10.0000 degrees / min ・ Sample holder: Glass, depth 0.2mm
Calculation method: As a result of measuring wide-angle X-ray diffraction using 3 g of the prepared sample (positively formed positive electrode material of the positive electrode), a diffraction angle of 28 was determined from an X-ray diffraction chart of the obtained diffraction angle (2θ) and diffraction peak intensity. Α-PbO ₂ positioned at .6 degrees and β-PbO ₂ positioned at a diffraction angle of 25.3 degrees were detected. Using the peak intensity (cps) of the waveform specified as each compound of α-PbO ₂ (110 face) and β-PbO ₂ (111 face), “peak intensity of α-PbO ₂ ” / “β-PbO ₂ The ratio of “peak intensity” was calculated as the ratio α-PbO ₂ / β-PbO ₂ . As a result of the measurement, the α-PbO ₂ / β-PbO ₂ ratio was 0.38.

The mass ratio of the positive electrode material to the negative electrode material (positive electrode material / negative electrode material) was 1.10.
<Example 2>
A lead storage battery was produced and measured in the same manner as in Example 1 except that an unformed positive electrode active material was produced as described below.

  First, 0.23% by mass of acrylic fiber as a reinforcing short fiber was added to the lead powder and dry-mixed. Next, an aqueous dispersion of 1.7% antimony and 15.3% tin dioxide (Mitsubishi Materials Electronics Chemicals; antimony-doped water dispersant TDL-1) as a solid content is 0.5 mass based on the lead powder. %, 7.0% by mass of water and 18% by mass of dilute sulfuric acid (specific gravity 1.35) were added and kneaded to prepare a paste.

  An expanded current collector produced by subjecting a rolled sheet made of a lead alloy to expansion processing was filled with the positive electrode active material paste, and then aged for 24 hours in an atmosphere of a temperature of 50 ° C. and a humidity of 98%. Then, it dried at the temperature of 50 degreeC for 16 hours, and produced the positive electrode plate which has a non-chemically formed positive electrode active material.

  The results of evaluation in the same manner as in Example 1 are shown in Table 1.

<Example 3>
A lead storage battery was produced and measured in the same manner as in Example 1 except that an unformed positive electrode active material was produced as described below.

  First, 0.23% by mass of acrylic fiber as a reinforcing short fiber was added to the lead powder and dry-mixed. Next, an aqueous dispersion of 1.7% antimony and 15.3% tin dioxide (made by Mitsubishi Materials Electronic Chemicals; antimony-doped water dispersant TDL-1) as a solid content with respect to the lead powder is 0.5 mass. %, Water 4.6 mass% and dilute sulfuric acid (specific gravity 1.35) 21.5 mass% were added and kneaded to prepare a paste.

  An expanded current collector produced by subjecting a rolled sheet made of a lead alloy to expansion processing was filled with the positive electrode active material paste, and then aged for 24 hours in an atmosphere of a temperature of 50 ° C. and a humidity of 98%. Then, it dried at the temperature of 50 degreeC for 16 hours, and produced the positive electrode plate which has a non-chemically formed positive electrode active material.

  The results of evaluation in the same manner as in Example 1 are shown in Table 1.

<Comparative Example 1>
A lead storage battery was produced and measured in the same manner as in Example 1 except that an unchemically formed positive electrode material was produced as described below.

  First, 0.07% by mass of acrylic fiber and 0.01% by mass of sodium sulfate were added to the lead powder as reinforcing short fibers and dry mixed. Next, an aqueous dispersion of 1.7% antimony and 15.3% tin dioxide (Mitsubishi Materials Electronics Chemicals; antimony-doped water dispersant TDL-1) as a solid content is 0.5 mass based on the lead powder. %, 10% by mass of water and 9% by mass of dilute sulfuric acid (specific gravity 1.28) were added and kneaded to prepare a positive electrode active material paste. In preparing the positive electrode active material paste, dilute sulfuric acid was added step by step to avoid a rapid temperature rise.

  An expanded current collector produced by subjecting a rolled sheet made of a lead alloy to expansion processing was filled with the positive electrode active material paste, and then aged for 24 hours in an atmosphere of a temperature of 50 ° C. and a humidity of 98%. Then, it dried at the temperature of 50 degreeC for 16 hours, and produced the positive electrode plate which has a non-chemically formed positive electrode active material.

  The results of evaluation in the same manner as in Example 1 are shown in Table 1.

<Comparative example 2>
A lead storage battery was produced and measured in the same manner as in Example 1 except that an unchemically formed positive electrode material was produced as described below.

  First, 0.07% by mass of acrylic fiber and 0.01% by mass of sodium sulfate were added to the lead powder as reinforcing short fibers and dry mixed. Next, 10% by mass of water and 9% by mass of dilute sulfuric acid (specific gravity 1.28) were added to the lead powder and kneaded to prepare a positive electrode active material paste. In preparing the positive electrode active material paste, dilute sulfuric acid was added step by step to avoid a rapid temperature rise.

  An expanded current collector produced by subjecting a rolled sheet made of a lead alloy to expansion processing was filled with the positive electrode active material paste, and then aged for 24 hours in an atmosphere of a temperature of 50 ° C. and a humidity of 98%. Then, it dried at the temperature of 50 degreeC for 16 hours, and produced the positive electrode plate which has a non-chemically formed positive electrode.

  The results of evaluation in the same manner as in Example 1 are shown in Table 1.

<Characteristic evaluation>
(Charge acceptance)
About the produced lead acid battery, after chemical conversion, it was left for about 12 hours, then was discharged at a constant current of 5.6 A at 25 ° C. for 30 minutes, further left for 6 hours, and then limited to 100 A at 2.33 V. As described above, constant voltage charging was performed for 60 seconds, and the current value from the start to the 5th second was measured. The relative ratio with the measurement result of Comparative Example 1 as 100 was evaluated. The results are shown in Table 1. When the measurement result was 100 or more, it was judged that the charge acceptability was excellent.

(5 hour rate capacity)
About the produced lead acid battery, it discharged with the electric current value of 5.6 A at 25 degreeC, and computed the 5-hour rate capacity | capacitance from the duration when it fell below 1.75V. The relative ratio with the measurement result of Comparative Example 1 as 96 was evaluated. The results are shown in Table 1. When the measurement result was 100 or more, it was judged that the 5-hour rate capacity was excellent.

(Low temperature high rate discharge characteristics)
About the produced lead acid battery, it discharged at -15 degreeC with the electric current value of 150 A, and the continuous capacity was computed from the duration when it fell below 1.0V. The relative ratio with the measurement result of Comparative Example 1 as 95 was evaluated. The results are shown in Table 1. When the measurement result was 100 or more, it was judged that the low-temperature high-rate discharge characteristics were excellent.

(ISS cycle characteristics)
Measurement of ISS cycle characteristics was performed as follows. Adjust the ambient temperature so that the battery temperature is 25 ° C., perform constant current discharge for 45A-59 seconds and 300A-1 seconds, then charge constant current / constant voltage for 100A-2.33V-60 seconds. The cycle test was conducted for 7200 cycles. This test is a cycle test that simulates the use of lead-acid batteries in ISS cars. In this cycle test, the amount of charge is small relative to the amount of discharge, so if charging is not performed completely, the battery gradually becomes insufficiently charged. As a result, the voltage at the first second when discharging at 300 A for 1 second is obtained. Decrease gradually. That is, if the negative electrode is polarized during constant current / constant voltage charging and switched to constant voltage charging at an early stage, the charging current is attenuated, resulting in insufficient charging. The relative ratio with the measurement result of Comparative Example 1 as 100 was evaluated. The results are shown in Table 1. When the measurement result was 100 or more, it was judged that the ISS cycle characteristics were excellent.

Claims (4)

A lead-acid battery comprising a positive electrode plate and a negative electrode plate facing each other via a separator, and an electrolyte solution,
The lead acid battery, wherein the positive electrode plate includes a positive electrode material, the negative electrode plate includes a negative electrode material, the positive electrode material has a specific surface area of 10 m ² / g or more, and the positive electrode material includes tin oxide. The positive electrode material comprises a beta-PbO ₂ and _{α-PbO 2, β-PbO} 2 and alpha-PbO ₂ in the ratio of the peak intensity of X-ray diffraction pattern _{(α-PbO 2 / β-} PbO 2) 0.4 The lead acid battery of Claim 1 which is the following.   The lead acid battery of Claim 1 or 2 with which the said positive electrode material contains an antimony oxide.   The lead acid battery of Claims 1-3 whose mass ratio (positive electrode material / negative electrode material) of the mass of the said positive electrode material and the mass of the said negative electrode material is 1.05 or more.