JP5050564B2 - Current collector for positive electrode or negative electrode of lead acid battery and method for producing the same, lead acid battery and method for producing the same - Google Patents

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 storage batteries have is early capacity loss (PCL). 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, 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 decrease.

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, T. Laitinen and four others.``The Effect of Antimony on The Anodic Behavior of Lead in Sulfuric Acid Solutions-I.Voltammetric Measurements '' Electrochimica Acta, Vol.36, No3 / 4, pp.605-614, (1991) Please refer to.

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 and enter the lead active material (PbO ₂ ). . Thereby, at the contact interface between the current collector and the reaction active material, β-PbO ₂ which is the reaction active material changes to α-PbO ₂ having a high discharge overvoltage with respect to the same discharge current. 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 unlikely to discharge, and the formation of a passive film is suppressed.

(2) Electron conductive oxide, interface adhesion:
When antimony ions are eluted from the antimony-containing lead-based alloy of the current collector, lead antimony composite oxide (PbxSbyOz) is generated at the contact interface between the current collector and the reaction active material. 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.

  Thus, when antimony-containing lead-based alloys (Pb—Sb, Pb—Sb—Sn) are 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 and is advantageous in maintenance as compared with the antimony-containing lead-based alloy (Pb-Sb, Pb-Sb-Sn). However, when a lead-tin-calcium (Pb-Sn-Ca) alloy is used instead of an antimony-containing lead (Pb-Sb, Pb-Sb-Sn) -based alloy as the positive electrode lattice, 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.

Patent Document 1 (Japanese Patent Laid-Open No. 63-164166) describes a lead-tin (0.5-2.0%)-calcium-antimony alloy in which antimony is 0.01-2.00% with respect to calcium 0.01-0.2%. Yes.
Patent Document 2 (Patent No. 3102000) discloses a positive electrode current collector 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 to form a body. 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.
In Patent Document 3 (Patent No. 3156333), a lead-tin-antimony alloy thin film is superimposed on the surface of a lead-tin-calcium alloy which is a base material and integrated by cold rolling as a measure against early capacity reduction. It is described that the lead-based alloy sheet is used as a current collector.

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, antimony ions are eluted from the antimony-containing lead-based alloy thin film on the surface, and (1) formation of α-PbO ₂ described above at the interface between the current collector and the reaction active material ( 2) Lead antimony complex oxide (PbxSbyOz) is generated. 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 (Japanese Patent Laid-Open No. 2005-32532) discloses a method in which carbon particles and an oxide are mixed in lead powder, and a positive electrode current collector is produced by powder metallurgy technology.
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 that 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.

Japanese Unexamined Patent Publication No. 63-164166 Patent No. 3102000 Patent No. 3156333 JP 2005-32532 A JP 2006-66173 A T. Laitinen and 4 others. “The Effect of Antimony on The Anodic Behavior of Lead in Sulfuric Acid Solutions-I. Voltammetric Measurements” Electrochimica Acta, Vol. 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 Electrotechnology” Surface Technology, Vol.26, pp.11-16, (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 function of suppressing the early capacity decrease due to antimony, it is necessary that antimony ions are eluted from the current collector at the contact interface between the current collector and the reaction active material. The elution of antimony ions is due to corrosion or oxidation of antimony.

  As described above, the suppression function against the early capacity reduction due to antimony can be obtained by generating lead antimony composite oxide (PbxSbyOz) at the contact interface between the current collector and the reaction active material.

Therefore, according to the present invention, lead antimony composite oxide (PbxSbyOz) is used as the current collector material instead of the antimony-containing lead-based alloy. The lead antimony composite oxide (PbxSbyOz) may be PbSb ₂ O ₆ .

According to the present invention, lead powder or lead-based alloy powder is used as the lead-containing powder that is the raw material of the current collector , and lead antimony composite oxide powder is used as the antimony-containing 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.

  These powders 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 antimony-containing 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.

  Conventionally, in the case of casting and rolling, antimony powder cannot be dispersed in the lead-tin-calcium alloy. However, according to the present invention, antimony is dispersed in the lead-tin-calcium alloy powder because powder rolling is used. be able to.

As described above, since the corrosion rate of antimony alone is higher than that of antimony in the lead alloy containing antimony, antimony ions can be rapidly supplied to the contact interface between the current collector and the reactive active material. Therefore, the production of α-PbO _{2 and} the production of lead antimony composite oxide at the contact interface between the current collector and the reaction active material are promoted, and early capacity reduction is suppressed.

  According to the present invention, it is an object of the present invention to provide a lead-acid battery current collector that can suppress an early capacity decrease without using a conventional antimony-containing lead-based alloy.

  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 storage battery includes a negative electrode terminal 11, a positive electrode terminal 12, a positive electrode plate 13, a negative electrode plate 14, a separator 15, a sulfuric acid electrolyte solution 16, a battery case 17, and a battery case cover 18. 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 and obtained by filling the positive electrode active material paste containing lead powder, red lead, lead sulfate, basic lead sulfate, additives, etc., and then drying it. Can do. By the chemical conversion, the positive electrode active material becomes lead dioxide (PbO ₂ ) at the interface with the current collector. 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 antimony simple powder or lead antimony composite oxide (PbxSbyOz) powder is used as the antimony-containing powder. In place of the antimony single metal powder, a bismuth single metal powder or a mixed powder of the antimony single metal powder and the bismuth single metal powder may be used. This will be described later.

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 the antimony elemental metal powder, a bismuth elemental metal powder or a mixed powder of the antimony elemental metal powder and the bismuth elemental metal powder may be used. The lead antimony composite oxide (PbxSbyOz) may be PbSb ₂ O ₆ .

  These powders 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 antimony-containing 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. Further, it may be a clad current collector in which a lead-tin-calcium (Pb-Sn-Ca) cast alloy sheet is used as a base material and a thin film of the rolled sheet is laminated thereon.

  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 form 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 film-like rolled sheet on a base material, that is, 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 antimony-containing lead powder that is a second powder is prepared. The antimony-containing powder is composed of an antimony simple substance powder or a lead antimony composite oxide (PbxSbyOz) powder. In place of the antimony simple substance powder, a bismuth simple substance powder or a mixed powder of the antimony simple substance powder and the bismuth simple substance powder may be used. These powders 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 the structure of the rolled sheet. Such a structure image is obtained by immersing the rolled sheet 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 3 to 13. Antimony single 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 prepared. 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 FIG. 7, and the results of the deep discharge cycle are shown in FIG.

  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 notches with a cutter and pulling the two masking portions 61a and 61b evenly.

  As a first powder, a gas atomized powder of lead-1.6% tin-0.08% calcium alloy was prepared, and as a second powder, a gas atomized powder of simple antimony was prepared, and a mixed powder of both was prepared. The content of simple antimony in the mixed powder was 3% 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. Separately, three types of comparative examples were prepared.

  (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 a gas atomized powder of lead-1.6% tin-0.08% calcium alloy and a gas atomized powder of antimony alone 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 to 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.

  (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, by clad formation. 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 clad phase has the same composition as the rolled sheet constituting the first current collector. In the state where the thin film is overlaid on the base material in this manner, as shown in FIG. Thereby, a second current collector having a surface cladding phase thickness of 20 μm and an overall thickness of 0.5 mm is formed.

  (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 having 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 a 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 had not been converted 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 coating 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. 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.

  (4) Three comparative examples were produced. 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 conditions of the deep discharge cycle used in the experiment of this example. Both charging and discharging were at a temperature of 25 ° C. and a current of 36 mA.

  FIG. 8 shows the result of the deep discharge cycle. The vertical axis represents the utilization rate of the reaction active material, and the horizontal axis represents the number of charge / discharge cycles. 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 reactive active material of the lead-5% tin-5% antimony cast rolled material which is the first comparative example. 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 the second comparative example. 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 the third comparative example.

  As shown by a curve 83, in the case of the lead-1.6% tin-0.08% calcium cast rolled material which is the third comparative example, the utilization factor of the reaction active material is lowered early, that is, the charge / discharge cycle characteristics are deteriorated. 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 the first comparative example, 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 obtained. 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 a curve 82, the lead-5% antimony cast rolled material of the second comparative example is compared with the lead-5% tin-5% antimony cast rolled material of the first comparative example of the curve 81. It is shown that a high utilization rate of the reaction active material is maintained from the beginning of the cycle, and early capacity reduction is suppressed.

  On the other hand, in the case of the first current collector according to the present invention, as shown by a curve 80, a high utilization factor of the reaction active material is maintained from the beginning of the cycle. The content of antimony alone in the first current collector was 3% by weight. This is smaller than the content of antimony in the comparative example. However, the utilization factor of the reaction active material in the first current collector is stable at a higher value than in the comparative example. This indicates that the antimony metal alone functions efficiently and effectively at the contact interface between the current collector and the reactive active material, compared to the behavior of antimony in conventional antimony-containing lead-based alloys.

  Although not shown in FIG. 8, the same applies to the second current collector having a clad phase and the third current collector having a lattice structure, and the utilization factor of the reaction active material is higher than that in the initial cycle. Maintained.

  The lead-5% tin-5% antimony cast rolled material, which is the first comparative example of the curve 81, showed the same behavior as the early capacity reduction at the beginning of the cycle. This is because the lead-5% tin-5% antimony alloy, which is the first comparative example, has higher corrosion resistance against antimony elution than the lead-5% antimony alloy current collector, which is the second comparative example. It is thought that there is in having. In the case of the lead-5% tin-5% antimony cast rolled material, which is the first comparative example, for higher corrosion resistance than the case of the lead-5% antimony alloy current collector, which is the second comparative example. The supply of antimony ions to the interface between the current collector and the reaction active material is considered to be delayed.

  In the case of the first current collector according to the present invention, such 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.

A gas atomized powder of lead-1.6% tin-0.08% calcium alloy was prepared as the first powder, and a lead antimony composite oxide PbSb ₂ O ₆ powder was prepared as the _second powder. First antimony composite oxide PbSb ₂ O ₆ as a second powder was mixed with 1% and 3% of the first powder to prepare first and second mixed powders, respectively. A rolled sheet was produced from the two mixed powders using the powder rolling apparatus shown in FIG. That is, a rolled sheet having a thickness of 1 mm was produced by the horizontally opposed first rolling rolls 24a and 24b, and re-rolled by the vertically opposed second rolling rolls 25a and 25b to produce a rolled sheet having a thickness of 0.5 mm. . Thus, a first rolled sheet was produced from the first mixed powder, and a second rolled sheet was produced from the second mixed powder.

When the composition of the rolled sheet was observed, the lead antimony composite oxide PbSb ₂ O ₆ particles were randomly dispersed. These two types of rolled sheets were cut out, and a commonly used positive electrode active material paste was applied to produce a flat plate-like positive electrode shown in FIG. 6A and a grid-like positive electrode by expanding shown in FIG. 6B. Using this positive electrode, a single plate cell was manufactured according to the procedure shown in FIG. 5, and a deep discharge cycle was performed. The deep discharge cycle conditions are as shown in FIG. Similar to FIG. 8, a graph was prepared in which the vertical axis represents the utilization factor of the reaction active material and the horizontal axis represents the number of charge / discharge cycles. According to it, either the case of the current collector made from the first mixed powder (1% PbSb ₂ O ₆ ) or the case of the current collector made from the second mixed powder (3% PbSb ₂ O ₆ ) However, it was shown that the utilization rate of the reaction active material was maintained at 40% or more until the end of the cycle, and the effect of suppressing the early capacity decrease was obtained.

  A lead-3% tin alloy gas atomized powder was prepared as the first powder, and a bismuth (Bi) gas atomized powder with a purity of 99.9% was prepared as the second powder. . The content of bismuth (Bi) in the mixed powder was 5% by weight. From this mixed powder, a rolled sheet was produced using a powder rolling apparatus shown in FIG. That is, a rolled sheet having a thickness of 1 mm was produced by the horizontally opposed first rolling rolls 24a and 24b, and re-rolled by the vertically opposed second rolling rolls 25a and 25b to produce a rolled sheet having a thickness of 0.5 mm. .

  When the composition of the rolled sheet was observed, bismuth (Bi) particles were randomly dispersed. The rolled sheet was cut out, and a commonly used positive electrode active material paste was applied to produce a flat plate-like positive electrode shown in FIG. 6A and a grid-like positive electrode by expanding shown in FIG. 6B. Using this positive electrode, a single plate cell was manufactured according to the procedure shown in FIG. 5, and a deep discharge cycle was performed. The deep discharge cycle conditions are as shown in FIG. Similar to FIG. 8, a graph was prepared in which the vertical axis represents the utilization factor of the reaction active material and the horizontal axis represents the number of charge / discharge cycles. According to it, it was shown that the utilization rate of the reaction active material was maintained at 40% or more until the end of the cycle, and the effect of suppressing the early capacity decrease was obtained.

  In the above-described examples, lead-1.6% tin-0.08% calcium alloy was used in Examples 1 and 2, and lead-3% tin alloy was used in Example 3 as the first powder. However, according to the present invention, as the first powder, an alloy containing at least one alloy element of tin, calcium, antimony, barium, silver, and bismuth based on lead may be used.

In the above-described examples, as the second powder, antimony alone was used in Example 1, lead antimony composite oxide PbSb ₂ O ₆ was used in Example 2, and bismuth alone was used in Example 3. However, instead of the antimony simple substance, a mixed powder of the antimony simple substance powder and the bismuth simple substance powder may be used. Furthermore, instead of the lead antimony composite oxide PbSb ₂ O ₆ , a lead antimony composite oxide (PbxSbyOz) having another composition may be used.

  Further, in the examples, a positive electrode current collector was produced, but the present invention is also applicable to a negative electrode current collector.

According to the present invention, antimony ions are eluted from the simple antimony contained in the current collector. That is, antimony is corroded or oxidized. Thereby, at the contact interface between the current collector and the reaction active material, β-PbO ₂ that is the reaction active material is changed to α-PbO ₂ with a high discharge overvoltage for the same discharge current. Alternatively, lead antimony composite oxide (PbxSbyOz) is generated at the contact interface between the current collector and the reaction active material. 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 the metal surface by rolling a mixed powder of a lead-containing powder and a single metal powder, and the functional material and structure that are problematic in a corrosive environment in which the reaction on the metal surface is controlled. There is a possibility of application to materials.

  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 conditions of the deep discharge cycle 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 ... Sulfuric acid electrolyte solution, 17 ... Battery case, 18 ... Battery case cover, 21 ... First hopper, 22 ... First One belt conveyor, 23 ... second hopper, 24a, 24b ... horizontal opposed first rolling roll, 25a, 25b ... vertically opposed second rolling roll, 26 ... rolled sheet winder, 29, 31 ... rolled sheet, 61, 61a 61b ... masking part, 62 ... positive electrode active material application part, 63 ... through hole,

Claims (17)

It is formed by powder rolling a mixed powder containing lead powder or lead-based alloy powder and lead antimony composite oxide (PbxSbyOz), and has a structure composed of crystal grains oriented in a specific direction with an aspect ratio of 3 to 13 A current collector for a positive electrode or a negative electrode of a lead storage battery. In the positive electrode or the negative electrode current collector of the lead-acid battery of claim 1, wherein said lead antimony composite oxide of the positive electrode or the negative current collector lead-acid batteries, which is a PbSb ₂ O _6. In claim 1 Symbol placement positive or negative electrode current collector of the lead-acid battery, the lead-based alloy powder, as a base of lead, tin, calcium, antimony, barium, silver, at least one alloy of bismuth A current collector for a positive electrode or a negative electrode of a lead storage battery, comprising an element. In the claims 3 positive lead-acid battery according or the negative current collector, the lead-based alloy powder, lead - tin - calcium (Pb-Sn-Ca) of a lead-acid battery, characterized in that an alloy powder positive or Current collector for negative electrode . According to claim 3 positive or negative electrode current collector of the lead-acid battery, wherein said lead-based alloy powder, lead - tin (Pb-Sn) positive or negative electrode current collector of the lead-acid battery, characterized in that an alloy powder body. In claim 1 Symbol placement positive or negative electrode current collector of the lead acid battery, characterized by having a lattice structure formed by the mixed powder to an expanding process a rolled sheet formed by powder rolling A current collector for a positive or negative electrode of a lead storage battery. The first layer has a two-layer structure having a mother layer first layer and a second layer rolled and pressure-bonded to the first layer,
A lead-acid battery positive electrode comprising a lead-tin-calcium alloy, wherein the second layer has the same composition as the positive electrode or negative electrode current collector according to any one of claims 1 to 4. Or the collector for negative electrodes . A positive electrode having a positive electrode active material, a negative electrode having a negative electrode active material, a separator sandwiched between the electrodes, and an electrolyte solution impregnating the positive electrode, the negative electrode, and the separator,
The at least one current collector of the positive electrode and the negative electrode, lead-acid battery, which is a positive or negative electrode current collector according to any one of claims 1-6. A positive electrode having a positive electrode active material, a negative electrode having a negative electrode active material, a separator sandwiched between the electrodes, and an electrolyte solution impregnating the positive electrode, the negative electrode, and the separator,
The lead acid battery according to claim 7 , wherein the current collector of at least one of the positive electrode and the negative electrode is the current collector for a positive electrode or a negative electrode according to claim 7 . Providing a first powder comprising lead powder or lead-based alloy powder;
Providing a second powder comprising lead antimony composite oxide (PbxSbyOz);
Mixing the first powder and the second powder to produce a mixed powder;
Generating a rolled sheet having a structure composed of crystal grains oriented in a specific direction with an aspect ratio of 3 to 13, by powder rolling the mixed powder;
Forming a current collector by cutting the rolled sheet;
Of a current collector for a positive electrode or a negative electrode of a lead-acid battery comprising: In the manufacturing method of the current collector for the positive electrode or negative electrode of the lead storage battery according to claim 10 ,
It said lead-based alloy powder, as a base of lead, tin, calcium, antimony, barium, silver, positive or negative electrode current collector lead-acid batteries, characterized in that it comprises at least one or more alloying elements of bismuth Manufacturing method. In the manufacturing method of the current collector for the positive electrode or the negative electrode of the lead storage battery according to claim 11 ,
The lead-based alloy powder is a lead-tin-calcium (Pb-Sn-Ca) alloy powder, and the method for producing a current collector for a positive electrode or a negative electrode of a lead-acid battery. The manufacturing method of claim 11 positive or negative electrode current collector of the lead-acid battery, wherein said lead-based alloy powder, lead - tin (Pb-Sn) lead-acid battery positive electrode or negative electrode, characterized in that the alloy powder Method for manufacturing a current collector. The method of manufacturing a positive electrode or a negative electrode current collector of the lead-acid battery of claim 10, said lead antimony composite oxide of the positive electrode or the negative electrode current collector of the lead-acid battery, which is a PbSb ₂ O ₆ Production method. The method for producing a current collector for a positive electrode or a negative electrode of a lead storage battery according to claim 10 ,
A method for producing a current collector for a positive electrode or a negative electrode of a lead storage battery, comprising the step of forming a current collector having a lattice structure by expanding the rolled sheet. In the manufacturing method of the current collector for the positive electrode or negative electrode of the lead storage battery according to claim 10 ,
The step of generating the rolled sheet includes:
Producing a lead-tin-calcium (Pb-Sn-Ca) cast alloy sheet;
A step of superimposing and rolling the rolled sheet on the cast alloy sheet to produce a rolled sheet having a two-layer structure;
The manufacturing method of the electrical power collector for positive electrodes or negative electrodes of a lead storage battery characterized by the above-mentioned. A step of producing a current collector by a method for producing a current collector for a positive electrode or a negative electrode of a lead storage battery according to any one of claims 10 to 16 ,
Applying a reactive material to the current collector;
Configuring a positive electrode with a current collector coated with the reactive active material;
Preparing an already formed negative electrode;
Inserting a separator between the positive electrode and the negative electrode and immersing the separator in an electrolytic solution;
A step of chemical conversion of the positive electrode.

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