JP2008210751A - Lead storage battery and current collector for lead storage battery and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a current collector for a lead storage battery which can control an early capacity deterioration. <P>SOLUTION: Lead powder or lead alloy powder is used as lead containing powder which is a raw material of a cathode current collector of a lead battery, and calcium oxide is used as alkaline-earth group metal oxide powder. The lead alloy powder is for example a lead-tin-calcium (Pb-Sn-Ca) alloy. In place of calcium oxide, alkaline metal oxide powder and other alkaline-earth group metal powder can be used. The lead containing powder and the calcium oxide powder are mixed and a sheet is manufactured by a powder rolling. The sheet is cut out to make a current collector. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lead storage battery, and more particularly to a current collector of a lead storage battery.

  A lead storage battery is a secondary battery that is particularly excellent in low-temperature characteristics among secondary batteries (storage batteries) and has a good balance between battery characteristics and cost. Lead-acid batteries have a higher weight per unit volume than lithium secondary batteries, and have fundamental problems in terms of energy density. However, lead-acid batteries are not only easy to handle as aqueous batteries, but they also decompose water due to the high reaction overvoltage (hydrogen overvoltage) of hydrogen generation and oxygen generation of lead electrode plates. A cell voltage of 2 volts that greatly exceeds the voltage is obtained. Therefore, it is widely spread as a secondary battery indispensable in the automobile society.

One of the problems that lead-acid batteries have is an early capacity drop (PCL: Preliminary Capacity Loss). The early capacity reduction occurs when a passive film having no electrical conductivity such as lead sulfate (PbSO ₄ ) is formed on the surface of the current collector of the positive electrode. The early capacity reduction occurs even if lead monoxide (PbO) is generated at the contact interface between the positive electrode current collector and the reaction active material. This will be described.

In general, the surface oxide of the current collector and the reactive active material are in contact with each other at the contact interface between the positive electrode current collector and the reactive active material of the lead storage battery. Therefore, in order to improve the adhesion between the positive electrode current collector and the reaction active material, the same lead dioxide (PbO ₂ ) as the reaction active material lead dioxide (PbO ₂ ) is densely formed on the current collector surface. It is desirable.

When lead monoxide (PbO) is generated on the surface of the current collector, the adhesion (electron conductivity) between the positive electrode current collector and the reaction active material decreases. Furthermore, lead monoxide (PbO) has a high electrical resistance, unlike lead dioxide (PbO ₂ ). Thus, when lead monoxide (PbO) is generated at the contact interface between the positive electrode current collector and the reaction active material, the charging current stops flowing, resulting in an early capacity reduction.

Therefore, the surface of the current collector is rapidly oxidized from lead oxide (PbO), which is a divalent (II) oxide, to lead dioxide (PbO ₂ ), which is a tetravalent (IV) oxide. desirable. That is, the current collector surface must be promptly covered with lead dioxide (PbO ₂ ).

  It is known that it is effective to use an antimony-containing lead-based alloy for the positive electrode current collector as an early capacity reduction measure, and there are several research reports. For example, see Non-Patent Document 1.

According to the knowledge so far, there are mainly the following two effects of the antimony-containing lead-based alloy.
(1) Formation of α-PbO _{2 When} an antimony-containing lead-based alloy is used for the positive electrode current collector, antimony ions are eluted from the antimony-containing lead-based alloy of the current collector due to the high potential of the positive electrode, which is a reaction active material. It penetrates into lead dioxide (PbO ₂ ). Thereby, at the contact interface between the current collector and the reaction active material, β-PbO ₂ that is the reaction active material changes to α-PbO ₂ having a low discharge potential. Thus, when α-PbO ₂ is generated at the contact interface between the current collector and the reaction active material, the reaction active material is in a state in which discharge is unlikely to occur, and generation of a passive film is suppressed.

(2) Electroconductive oxide, adhesion at the interface When antimony ions are eluted from the antimony-containing lead-based alloy of the current collector, lead antimony complex oxide (PbxSbyOz) at the contact interface between the current collector and the reactive active material Is generated. Since this composite oxide electronically improves the adhesion at the contact interface between the current collector and the reaction active material, the electron conductivity is increased.

  As described above, when an antimony-containing lead-based alloy (Pb-Sb, Pb-Sb-Sn) is used for the positive electrode current collector, it is effective for early capacity reduction measures. However, since the hydrogen overvoltage of antimony is lower than the hydrogen overvoltage of lead, there is a weakness that promotes the water decomposition reaction of the electrolyte. That is, since water is reduced by the self-discharge reaction, there is a maintenance problem that the frequency of water supply must be increased.

  A positive electrode current collector of a lead storage battery needs strength and corrosion resistance. Lead-tin-calcium (Pb-Sn-Ca) alloy is a lead-based alloy having excellent strength and corrosion resistance. The lead-tin-calcium (Pb-Sn-Ca) alloy has less self-discharge reaction than the antimony-containing lead-based alloy (Pb-Sb, Pb-Sb-Sn), and is advantageous in terms of maintenance. However, when a lead-tin-calcium (Pb-Sn-Ca) alloy is used as the positive electrode lattice instead of the antimony-containing lead (Pb-Sb, Pb-Sb-Sn) based alloy, there is a problem of early capacity reduction.

In order to solve the problem of early capacity reduction, it is known to use a lead antimony alloy by casting as the material of the positive electrode current collector. Antimony is casted into an alloy and rolled into a current collector. Therefore, a combination of antimony and a lead-tin-calcium alloy is conceivable. However, when antimony is contained in the molten lead-tin-calcium alloy, stibine (SbH ₃ ), which is a toxic gas, is generated by the combination of calcium and antimony.

  In Patent Document 1 (Japanese Patent Laid-Open No. 63-164166), lead-tin (0.5-2.0.1) containing 0.01-2.00% of antimony with respect to 0.01-0.2% of calcium is disclosed. 0%)-calcium-antimony alloy is described.

  In Patent Document 2, a positive electrode current collector is formed by bonding a lead-antimony alloy (antimony 0.005 wt% to 0.250 wt%) containing no calcium to the surface of a lead-calcium alloy that is a base material. It is described. In this example, the strength of the current collector is maintained by the lead-antimony alloy as a base material at the same time as the early capacity reduction measures.

  Patent Document 3 discloses a lead-based alloy sheet obtained by superimposing a lead-tin-antimony alloy thin film on the surface of a lead-tin-calcium alloy as a base material and integrating by cold rolling as an early capacity reduction measure. The use as a current collector is described.

The technologies described in Patent Documents 2 and 3 both have an alloy having a two-layer structure by cold-rolling a lead-antimony alloy thin film on a lead-tin-calcium alloy which is a base material. A current collector sheet is obtained. In such a two-layer structure, the elution of antimony ions from the antimony-containing lead-based alloy thin film on the surface causes the generation of (1) α-PbO ₂ described above at the interface between the current collector and the reactive active material ( 2) Formation of lead antimony composite oxide (PbxSbyOz) occurs. The shape of the current collector is a so-called expanded lattice in which an incision is made in a two-layer structure alloy sheet and pulled from the left and right to form a mesh.

Patent Document 4 discloses a method in which carbon particles and oxides (SiO ₂ , Al ₂ O ₃ , ZrO ₂ , SnO ₂ , BaPbO ₃ ) are mixed in lead powder, and a positive electrode current collector is produced by powder metallurgy technology. It is shown.

  Patent Document 5 (Japanese Patent Laid-Open No. 2006-66173) describes that corrosion elongation is suppressed by producing a lead-tin-antimony alloy current collector, which is an antimony alloy, using a powder rolling technique. .

  Non-Patent Document 2 details the influence of bismuth (Bi) in a positive electrode current collector on a lead battery.

JP 63-164166 A Patent 3102000 Japanese Patent No. 3156333 JP 2005-32532 A JP 2006-66173 A T.A. Laitinen and 4 others. “The Effect of Antimony on The Anodical Behavior of Lead in Sulfuric Acid Solutions—I. Voltammetric Measurements, ElectrochiamericArc. 36, No 3/4, pp. 605-614, (1991) S. R. ELLIS and 3 others. “A Short Review of the Effect of Bismuth on Lead-Cell Electrochemistry”, Surface Technology, Vol. 26, pp11-16, (1985)

  As described above, when an antimony-containing lead-based alloy is used for the positive electrode current collector, it is effective for an early capacity reduction measure. However, antimony-containing lead-based alloys reduce hydrogen overvoltage and promote self-decomposition.

  In a corrosion-resistant alloy such as a lead-tin-antimony alloy, antimony ionization is delayed, and a suppression effect against early capacity reduction occurs, but a time delay occurs. Such unstable factors also hinder the use of antimony-containing lead alloys.

  There is a combination of antimony and a lead-tin-calcium alloy as a problem in a lead antimony alloy by casting. In this case, toxic stibine gas is generated from the molten lead-tin-calcium alloy and antimony.

  Therefore, conventionally, a thin film of a lead-based alloy such as a lead-antimony alloy or a lead-tin-antimony alloy is laminated on a base metal-free alloy, so-called cladding, and a current collector is formed. Forming.

  The objective of this invention is providing the electrical power collector of the lead storage battery which can suppress an early capacity | capacitance fall, without using the antimony containing lead type alloy like the past.

As described above, in order to obtain a suppression function for early capacity loss, that the current collector and the discharge potential on the active material surface is different from the β-PbO ₂ α-PbO ₂ is generated is an important factor. Since α-PbO ₂ is stable in the alkali region, it is generated when the interface between the current collector and the active material becomes more alkaline. Therefore, α-PbO ₂ occurs due to the intrusion of antimony ions into the β-PbO ₂ lattice due to the crystal structure as described above, but the stability of PbO ₂ differs between the β-type and α-type with respect to pH. Therefore, α-PbO ₂ is also phase-changed from β-PbO ₂ by changing the pH.

In the present invention, a powder rolling technique is applied as a method for making the current collector / active material interface alkaline, and this object is achieved by mixing alkali metal oxide or alkaline earth metal oxide powder in the lead powder alloy raw material. Could be achieved. That is, powder such as CaO is mixed in the lead alloy metal powder and rolled. Using this as the current collector sheet, the reaction active material is applied onto this sheet. CaO mixed in the current collector reacts with the water in the lead battery electrolyte at the interface between the current collector and the active material thus configured, and Ca (OH) ₂ that is a strong alkali is present at the interface. (CaO + H ₂ O → Ca (OH) ₂ ). In the interfacial pH region where Ca (OH) ₂ is generated, β-PbO ₂ is thermodynamically unstable and changes to α-PbO ₂ . Thereby, passivation of the current collector interface is suppressed, and the electronic conductivity between the current collector and the active material interface can be maintained with respect to charging and discharging, so that early capacity reduction is suppressed. In casting, CaO having a lower specific gravity than lead cannot be uniformly dispersed and mixed with molten lead. Therefore, the current collector was manufactured by uniformly dispersing CaO in the current collector by powder rolling.

  ADVANTAGE OF THE INVENTION According to this invention, the early capacity | capacitance fall of a lead storage battery can be suppressed, without using the conventional antimony containing lead type alloy as a collector of a lead storage battery.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the examples unless it exceeds the gist of the invention.

FIG. 1 shows a basic configuration of a lead storage battery according to the present invention. The lead acid battery has a negative electrode terminal 11, a positive electrode terminal 12, a positive electrode plate 13, a negative electrode plate 14, a separator 15, a battery case 16, and a battery case cover 17, and sulfuric acid is stored in the battery case 16 as an electrolytic solution. It has been. A positive electrode active material paste is applied to the current collector of the positive electrode plate 13. As the positive electrode active material, known materials may be used. After filling the positive electrode active material paste containing lead powder, red lead, lead sulfate, basic lead sulfate, additives, etc., this is aged and dried. Can be obtained. Subsequently, the positive electrode active material becomes lead dioxide (PbO ₂ ) by chemical conversion. Below, the manufacturing method of the electrical power collector of the positive electrode plate 13 is demonstrated.

  First, the material of the positive electrode current collector according to the present invention will be described. According to the present invention, lead powder or lead-based alloy powder is used as the lead-containing powder, and calcium oxide (CaO) powder that is easy to handle is used as the alkaline earth metal oxide powder.

The lead-based alloy powder contains at least one alloy element of tin, calcium, antimony, barium, silver, and bismuth based on lead. The lead-based alloy powder may be a lead-tin-calcium (Pb-Sn-Ca) alloy or a lead-tin (Pb-Sn) alloy powder. Instead of CaO powder, BaO powder, MgO powder, and alkali metal oxide powder such as Na ₂ O ₂ and K ₂ O ₂ powder may be used. The lead-based alloy powder can be produced by a gas atomization method in which a rapidly solidified powder is produced by spraying molten metal into dry air. Lead-containing powder and CaO powder are mixed, and the mixed powder is formed by powder rolling to form a sheet. The rolled sheet thus formed has a structure composed of crystal grains oriented in a specific direction with an aspect ratio of 3 to 13. The rolled sheet is cut out to form a current collector. A current collector having a lattice structure may be formed by expanding a rolled sheet.

  FIG. 2 shows a basic configuration of a powder rolling apparatus used for manufacturing a current collector according to the present invention. The powder rolling apparatus of this example includes a first hopper 21, a first belt conveyor 22, a second hopper 23, horizontally opposed first rolling rolls 24a and 24b, vertically opposed second rolling rolls 25a and 25b, and rolled sheet winding. Machine 26.

  FIG. 2A shows a method of manufacturing a rolled sheet that is a material for the current collector of the positive electrode plate 13. The first hopper 21 is charged with mixed powder that is a raw material for the current collector of the positive electrode plate. The mixed powder 27 dropped from the first hopper 21 passes through a gap (slit) between the first hopper 21 and the first belt conveyor 22 and is conveyed to the second hopper 23. The raw material passes through the horizontally opposed first rolling rolls 24a and 24b to become a rolled sheet having a thickness of 1 mm. The rolled sheet 28 is further re-rolled by passing through the vertically opposed second rolling rolls 25a and 25b to become a rolled sheet 29 for a current collector having a thickness of 0.5 mm. The rolled sheet 29 thus produced is wound up in a roll shape by a rolled sheet winder 26.

  FIG. 2B shows a method for manufacturing a rolled sheet having a two-layer structure, which is a material for the current collector of the positive electrode plate 13. In this example, the raw material passes through the horizontally opposed first rolling rolls 24a and 24b to become a rolled sheet having a thickness of 100 μm. The rolled sheet 28 and the cast rolled sheet 30 having a thickness of 2.5 mm are overlapped and passed through the vertically opposed second rolling rolls 25a and 25b. Thereby, a rolled sheet 31 for a current collector having a thickness of 0.5 mm is obtained. The rolled sheet 31 is formed by laminating a thin rolled sheet on a base material, that is, by forming a clad. The rolled sheet 31 thus produced is wound up in a roll shape by a rolled sheet winder 26.

  With reference to FIG. 3, the manufacturing method of the positive electrode electrical power collector for lead acid batteries by this invention is demonstrated. In step S101, a lead-containing powder that is a first powder is prepared. The lead-containing powder is composed of lead powder or lead-based alloy powder. In step S102, an alkaline earth metal oxide powder and an alkali metal oxide powder, which are the second powder, are prepared. The lead-based alloy powder can be produced by a gas atomization method. The gas atomization method is a method of generating rapidly solidified powder by spraying molten metal into dry air.

  In step S103, the first powder and the second powder are mixed to generate a mixed powder. In step S104, the mixed powder is powder-rolled to produce a rolled sheet. A rolled sheet is produced using the powder rolling apparatus shown in FIG.

  In step S105, a current collector is formed from the rolled sheet. When producing a flat positive plate, the rolled sheet is cut into a rectangle. When creating a grid-like positive electrode plate, a rolled sheet cut into a rectangle is cut with a cutter, and both ends are pulled evenly. In this way, the positive electrode active material paste is applied to the manufactured current collector plate and dried to form the positive electrode plate.

  FIG. 4 is a photograph showing an example of the structure of a rolled sheet. Such a structure image is obtained by cutting the rolled sheet plate in the width direction and immersing it in an etching solution, and then imaging it. As shown in the figure, the structure of the rolled sheet is composed of fine particles of gas atomized powder which is a raw material for powder rolling, and the aspect ratio which is the aspect ratio of the particle diameter is 2 to 13. This is an example in which CaO particles, which are alkaline earth metal oxide particles, are randomly dispersed in this structure.

  With reference to FIG. 5, the procedure of the experiment performed in order to evaluate the electrical power collector for lead acid batteries by this invention is demonstrated. In step S201, a positive electrode current collector was produced. In step S202, a chemically converted negative electrode was prepared. In step S203, a positive electrode, a negative electrode, a separator, and the like were assembled to produce a single plate cell. In step S204, chemical conversion of the positive electrode was performed. In step S205, a deep discharge cycle was performed. The conditions of the deep discharge cycle are shown in Table 1 (temperature 25 ° C., current 36 mA).

  FIG. 6 shows an example of the structure of the current collector of the positive electrode plate used in the experiment. 6A shows an example of the structure of a flat plate-like positive electrode plate, and FIG. 6B shows an example of a lattice-like positive plate formed by expanding. As shown in FIG. 6A, the flat positive electrode plate has a positive electrode active material application part 62 coated with a reactive active material and a masking part 61 masked with a sulfuric acid resistant adhesive insulating tape. The positive electrode active material application part 62 is provided with five through holes 63 having a diameter of 5 mm. A lead wire 65 that is a lead wire is connected to the masking portion 61 by soldering. As shown in FIG. 6B, the grid-like positive electrode plate has two masking parts 61a and 61b and an active material application part 64 between them. The positive electrode active material application part 64 has a lattice shape or a mesh structure. The mesh structure is formed by generating cuts with a cutter and pulling the two masking portions 61a and 61b equally to the left and right.

As the first powder, an air-cooled gas atomized powder of lead-1.6% tin-0.08% calcium alloy with a particle size of less than 75 μm is prepared, and as the second powder, calcium oxide CaO powder having an average particle size of about 15 μm. Was prepared, and a mixed powder of both was prepared. The CaO content in the mixed powder was 0.5% by weight. From this mixed powder, a rolled sheet was produced using a powder rolling apparatus shown in FIG. Three types of current collectors described below were produced using the rolled sheet thus produced.
(Example 1)
The first current collector is a plate-like current collector shown in FIG. 6A. First, a rolled sheet was produced by the method shown in FIG. As described above, a mixed powder of gas atomized powder of lead-1.6% tin-0.08% calcium alloy and CaO powder is prepared. The mixed powder is passed through horizontally opposed first rolling rolls 24a and 24b to produce a 1 mm thick rolled sheet, which is re-rolled by vertically opposed second rolling rolls 25a and 25b, and has a thickness of 0.5 mm. A rolled sheet was prepared. This rolled sheet was cut out to produce a plate-like current collector shown in FIG. 6A. Therefore, the composition of the first current collector is the same as the composition of the mixed powder and the rolled sheet.
(Example 2)
The second current collector is a clad current collector. The second current collector was produced by laminating a powder rolled sheet with a thickness of 100 μm on a cast rolled sheet with a thickness of 2.5 mm as a base material, that is, clad. The cast cast sheet of the base material is a Pb-1.6% Sn-0.08% Ca cast rolled alloy, and the powder rolled sheet used for the cladding phase has the same composition as the rolled sheet constituting the first current collector. Have In the state where the thin film is stacked on the base material in this way, as shown in FIG. 2B, rolling is performed by the vertically opposed second rolling rolls 25a and 25b of the powder rolling apparatus. Thereby, a second current collector having a surface cladding phase thickness of 20 μm and an overall thickness of 0.5 mm is formed.
(Example 3)
The third current collector is a current collector on a lattice or mesh shown in FIG. 6B. Similarly to the first current collector, the rolled sheet was cut into a plate shape and produced by expanding. In the expanding process, incisions with a length of 5 mm are provided with a cutter on the surface of a flat plate-like current collector at an interval of about 1 mm, and a grid or mesh is formed by pulling evenly to the left and right. That is, a so-called expanded lattice is formed in which a lattice bone is formed between the cuts of the cutter. The thickness of the expanded lattice is about 0.5 mm.

  As shown in FIG. 6A, a positive electrode active material paste that was not formed was applied to one surface of the three types of current collectors thus formed. The dimensions of the positive electrode active material application part 62 were 30 mm × 15 mm × 0.5 mmt, and the application amount of the positive electrode active material was 1.8 g. A portion other than the positive electrode active material application portion 62 is a masking portion 61, which is masked with a sulfuric acid resistant adhesive insulating tape to define a reaction area. As shown in FIG. 6B, in the case of the third current collector, the area of the positive electrode active material application part 62 is a projected area of a lattice-shaped region. As shown in FIG. 6A, in the case of the first and second current collectors, five holes 63 having a diameter of 5 mm were formed in the positive electrode active material application part 62. These holes 63 were equally arranged at the center and the periphery thereof.

  Three comparative examples were prepared. In these comparative examples, an alloy according to the prior art is used as the material for the current collector of the positive electrode. In the first comparative example, lead-5% tin-5% antimony cast rolled material, in the second comparative example lead-5% antimony cast rolled material, in the third comparative example, lead-1.6% tin. -0.08% calcium cast rolled material was used. Using these materials, a plate-shaped current collector plate was formed as shown in FIG. 6A. The area and coating amount of the positive electrode active material application part 62 of these comparative examples were the same as those of the first current collector, and five holes with a diameter of 5 mm were formed in the positive electrode active material application part 62.

  FIG. 7 shows the results of the deep discharge cycle in Table 1. The vertical axis represents the utilization rate of the reaction active material, and the horizontal axis represents the number of charge / discharge cycles. The utilization rate is a percentage of the theoretical capacity calculated from the amount of active material in each cycle after capacity confirmation (initial capacity) (each cycle discharge capacity / theoretical capacity). A curve 80 shows a change in the utilization rate of the reaction active material of the first current collector according to the present invention.

  A curve 81 shows a change in the utilization factor of the reaction active material of the lead-5% tin-5% antimony cast rolled material which is Comparative Example 1. A curve 82 shows a change in the utilization factor of the reaction active material of the lead-5% antimony cast rolled material which is Comparative Example 2. A curve 83 shows a change in the utilization factor of the reaction active material of the lead-1.6% tin-0.08% calcium cast rolled material which is Comparative Example 3.

  As shown by the curve 83, in the case of the lead-1.6% tin-0.08% calcium cast rolled material which is the comparative example 3, the utilization rate of the reaction active material is lowered early, that is, the charge / discharge cycle characteristics are deteriorated. To do. This indicates that an early capacity drop has occurred. As shown by the curve 81, in the case of the lead-5% tin-5% antimony cast rolled material which is Comparative Example 1, the utilization factor of the reaction active material is reduced at the beginning of the cycle, and the same behavior as the early capacity reduction is exhibited. However, in the middle of the cycle, it is observed that the utilization factor of the reaction active material is increased and the early capacity reduction is suppressed. As shown by the curve 82, in the case of the lead-5% antimony cast rolled material of Comparative Example 2, compared to the lead-5% tin-5% antimony cast rolled material of Comparative Example 1 of the curve 81, from the beginning of the cycle. It is shown that a high utilization rate of the reaction active material is maintained and early capacity reduction is suppressed.

  On the other hand, in the case of the first current collector (Example 1) according to the present invention, as shown by a curve 80, a high utilization factor of the reactive active material is maintained from the beginning of the cycle. The content of CaO powder in the first current collector was 0.5% by weight. Although not shown in FIG. 7, in the case of the second current collector (Example 2) having a cladding phase and the third expanded grid current collector (Example 3) having a lattice-like structure, 0. The current collector roll-formed from the lead alloy powder raw material mixed with 5% CaO powder showed the same cycle characteristics and maintained a higher utilization factor of the reaction active material than the initial cycle.

  The lead-5% tin-5% antimony cast rolled material, which is Comparative Example 1 of curve 81, behaved similarly to the early capacity reduction at the beginning of the cycle. This is because the lead-5% tin-5% antimony alloy which is Comparative Example 1 has a higher corrosion resistance against antimony elution than the lead-5% antimony alloy current collector which is Comparative Example 2. It is believed that there is. In the case of the lead-5% tin-5% antimony cast rolled material of Comparative Example 1, the current collector has higher corrosion resistance than the case of the lead-5% antimony alloy current collector of Comparative Example 2. It is thought that the supply of antimony ions to the interface between the reaction material and the reaction active material is delayed.

  In the case of the current collector according to the present invention, such a behavior does not appear, the utilization rate of the reaction active material excellent in stability is maintained from the beginning of the cycle, and early capacity reduction suppression is clear.

According to the present invention, the alkaline earth metal oxide such as CaO contained in the current collector makes the contact interface between the current collector and the reactive active material more alkaline than the lead battery electrolyte region. Thereby, β-PbO ₂ which is a reaction active material can be stabilized as α-PbO ₂ having a low discharge potential at the current collector / active material contact interface. Thereby, an early capacity drop can be suppressed.

  Such a reaction mechanism is applicable not only to the current collector of the lead storage battery but also to various metal surface environments.

  The present invention controls the composition of a metal surface by rolling a mixed powder of a lead-containing powder, an alkaline earth metal oxide powder, and an alkali metal oxide powder, thereby controlling the metal surface, the metal, the gas phase, and the metal and the liquid. There is a possibility of application to a functional material, a structural material, or the like that controls a reaction at a phase interface, a metal-solid phase interface, or a metal-solid-liquid phase interface.

  The example of the present invention has been described above, but the present invention is not limited to the above-described example, and various modifications can be easily made by those skilled in the art within the scope of the invention described in the claims. It will be understood.

It is a figure which shows the structure of the lead acid battery by this invention. It is a figure which shows the structure of the powder rolling apparatus used for manufacture of the positive electrode electrical power collector of the lead acid battery by this invention. It is a figure explaining the manufacturing method of the positive electrode electrical power collector for lead acid batteries by this invention. It is a figure which shows the structure | tissue of the rolled sheet used for the positive electrode electrical power collector for lead acid batteries by this invention. It is a figure which shows the procedure of the experiment conducted in order to evaluate the positive electrode electrical power collector for lead acid batteries by this invention. It is a figure which shows the example of the structure of the electrical power collector of the positive electrode plate used for the experiment conducted in order to evaluate the positive electrode electrical power collector for lead acid batteries by this invention. It is a figure which shows the result of the experiment conducted in order to evaluate the positive electrode electrical power collector for lead acid batteries by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Negative electrode terminal, 12 ... Positive electrode terminal, 13 ... Positive electrode plate, 14 ... Negative electrode plate, 15 ... Separator, 16 ... Battery case, 17 ... Battery case cover, 21 ... First hopper, 22 ... First belt conveyor, 23 ... Second hopper, 24a, 24b ... Horizontally opposed first rolling roll, 25a, 25b ... Vertically opposed second rolling roll, 26 ... Rolled sheet winder, 29, 31 ... Rolled sheet, 61, 61a, 61b ... Masking section, 62 ... Positive electrode active material application part, 63 ... Through-hole, 64 ... Lattice-like positive electrode active material application part, 65 ... Lead wire, 80 ... Change in utilization factor of reaction active material of the first current collector according to the present invention, 81 ... change in utilization rate of reaction active material of lead-5% tin-5% antimony cast rolling material, 82 ... change in utilization rate of reaction active material of lead-5% antimony cast rolling material, 83 ... lead-1.6 % Tin-0.08% calcium Changes in utilization of the reaction active material forming the rolled material

Claims (10)

It is formed by powder rolling a mixed powder containing lead powder or lead-based alloy powder and alkaline earth metal oxide or alkali metal oxide, and is composed of crystal particles oriented in a specific direction with an aspect ratio of 2 to 13 A lead-acid battery current collector characterized by having an organization. The current collector for a lead storage battery according to claim 1, wherein the alkaline earth metal oxide includes at least one of calcium oxide powder, magnesium oxide powder, and barium oxide powder. 3. The lead-acid battery according to claim 1, wherein the lead-based alloy powder contains at least one alloy element of tin, calcium, antimony, barium, silver, and bismuth based on lead. 4. Current collector. The current collector for a lead storage battery according to any one of claims 1 to 3, wherein the current collector has a lattice structure formed by expanding a rolled sheet formed by powder rolling the mixed powder. A positive electrode having a positive electrode active material; a negative electrode having a negative electrode active material; a separator sandwiched between the two electrodes; an electrolyte solution impregnating the positive electrode, the negative electrode, and the separator; At least one electrical power collector is a current collector of any one of Claims 1-4, The lead acid battery characterized by the above-mentioned. Preparing a first powder containing lead powder or a lead-based alloy powder; preparing a second powder containing an alkaline earth metal oxide or an alkali metal oxide; the first powder and the first powder; A mixed sheet is produced by mixing the two powders, and a rolled sheet having a structure composed of crystal grains oriented in a specific direction having an aspect ratio of 3 to 13 is produced by powder rolling the mixed powder. A method of manufacturing a current collector for a lead storage battery, comprising: a step; and forming a current collector by cutting the rolled sheet. The lead-acid battery current collector according to claim 6, wherein the lead-based alloy powder contains at least one alloy element of tin, calcium, antimony, barium, silver, and bismuth based on lead. Body manufacturing method. The lead-acid battery current collector manufacturing method according to claim 6 or 7, wherein the lead-based alloy powder is a lead-tin-calcium (Pb-Sn-Ca) alloy powder. The method for producing a current collector for a lead storage battery according to claim 6 or 7, wherein the lead-based alloy powder is a lead-tin (Pb-Sn) alloy powder. Furthermore, the manufacturing method of the electrical power collector of the lead storage battery of any one of Claims 6-9 including the step which forms the electrical power collector which has a lattice structure by expanding the said rolling sheet | seat.

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