JP2005044761A - Lattice board for lead-acid battery, and lead-acid battery using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the corrosion resistance and mechanical strength of a lattice board, prevent the elongation of a lattice, and achieve the weight reduction of the lattice board. <P>SOLUTION: The effective diameter (value obtained by dividing four times of the area of a polygon of the lattice by the peripheral length of the polygon) of the square lattice of the lattice board composed of a lead-base alloy composed of calcium of 0.02 mass % or more and less than 0.05 mass %, tin of 0.4 mass % or more and 2.5 mass % or less, barium of 0.002 mass % or more and 0.014 mass % or less, and the rest part comprising lead and inevitable impurities, or of a lead alloy containing at least one element selected from a group composed of silver of 0.005 mass % or more and 0.07 masss% or less, bismuth of 0.01 mass % or more and 0.10 mass % or less, and thallium of 0.001 mass % or more and 0.05 mass % or less besides the composition of the lead-base alloy is made twice, preferably twice or more and ten times or less of the thickness of the lattice board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lattice substrate of a lead storage battery and a lead storage battery using the same.

  A lead-acid battery uses a grid substrate made of a lead alloy, and an electrode plate group in which positive and negative plates, which are coated and filled with a paste-like active material, are alternately stacked via a separator, is stored in a battery case, and diluted sulfuric acid is stored in the battery case. It is manufactured by injecting an electrolyte solution consisting of

  In these lead storage batteries, it is said that the lattice substrate used for the positive electrode is influenced by the life, and those having excellent corrosion resistance and mechanical strength are required. However, none of the known lead alloys can be said to be sufficient. Therefore, by increasing the thickness of the lattice substrate, a lattice substrate design that compensates for a decrease in the lattice cross-sectional area due to corrosion and a corresponding decrease in mechanical strength is made. It was. In addition, the lattice substrate is provided with an oblique lattice to suppress the elongation of the lattice substrate (see Patent Document 1), and the longitudinal lattice cross-sectional area of the inner bone far from the ear is increased to prevent damage due to the elongation of the lattice substrate. (See Patent Document 2), however, the effects are limited and are not satisfactory.

Japanese Patent Laid-Open No. 2001-236963 (see the right column, page 2, lines 6 to 27, FIG. 1) JP 2001-266896 A (see page 2, left column, line 50 to right column, line 18, line 1)

  In order to solve these problems, the present inventors previously proposed a completely new lead alloy (Japanese Patent Application No. 2003-147589). This lead alloy has a calcium content of 0.02% to less than 0.05%, tin content of 0.4% to 2.5%, barium content of 0.002% to 0.014%, and the balance being lead. Inevitable impurities, or further 0.005% by mass to 0.07% by mass silver, 0.01% by mass to 0.10% by mass bismuth, 0.001% by mass to 0.05% It contains at least one element selected from the group consisting of thallium and less than mass%. According to this alloy, the amount of corrosion in dilute sulfuric acid having a specific gravity of 1.280 (20 ° C.) is small, and the creep strength is also excellent.

  In view of the need to improve the corrosion resistance and mechanical strength of the exercise substrate and to reduce the weight of the lattice substrate, the present inventor has further increased the demand for longer life and lighter weight in lead-acid batteries. Using an alloy, focusing on the elongation as a lattice substrate, the inventors have studied to suppress the elongation as much as possible and have reached the present invention.

  In the present invention, calcium is 0.02 mass% or more and less than 0.05 mass%, tin is 0.4 mass% or more and 2.5 mass% or less, barium is 0.002 mass% or more and 0.014 mass% or less, and the balance is lead. Inevitable impurities, or further 0.005% by mass to 0.07% by mass silver, 0.01% by mass to 0.10% by mass bismuth, 0.001% by mass to 0.05% The grid effective diameter of the lattice substrate using a lead alloy containing at least one element selected from the group consisting of thallium of less than mass% (value obtained by dividing the area of the polygon by 4 times the perimeter of the polygon) It is characterized in that it is at least twice the thickness of the lattice substrate.

  It is considered that the elongation of the electrode plate occurs because the corrosion product on the surface of the substrate undergoes a volume change as the storage battery is charged and discharged, and the substrate itself stretches due to the creep phenomenon caused by the stress. Naturally, the corrosion resistance of the substrate itself is greatly influenced by the properties of the corrosion products generated on the substrate surface. That is, when the corrosion product is porous, the electrolyte solution is sufficiently supplied, so that charge / discharge is likely to occur, and the volume change becomes remarkable. As a result, a new surface appears on the lattice surface of the substrate, and a vicious cycle occurs in which corrosion further proceeds. On the other hand, if the corrosion product is dense, the electrolytic solution is difficult to enter, so that charging / discharging is unlikely to occur and a stable state can be maintained. The above lead alloy has the property of being resistant to creep as well as corrosion resistance by the action of an additive element to lead, and can maintain a more stable state. Therefore, the grid of the positive grid substrate, which has conventionally required a fine grid or a thick grid, is roughened, and even if it is thinned, it is difficult to stretch, and the weight can be reduced.

  The lattice substrate of the present invention can be obtained by gravity casting, continuous casting, further rolling and punching after rolling. And the effect is remarkable by using especially for a positive electrode plate, but you may use for a negative electrode plate.

  In addition, the use of lead-acid batteries using these grid substrates can be used for automotive and industrial cycle use (charging and discharging are repetitively used) and for standby (used in preparation for emergencies). For all types of lead-acid batteries such as liquid type (with a sufficiently large amount of electrolyte in the battery case), seal type (with enough electrolyte to impregnate the electrode plate group), and other wound type cylindrical batteries Applicable.

  According to the present invention, it is possible to provide a lattice substrate that can suppress the elongation of the lattice substrate and can be reduced in weight, and when used in a lead storage battery, a lead storage battery that achieves both long life and light weight can be obtained. There is an effect that it can be provided.

  As shown in FIG. 1 by gravity casting using non-oxidized lead alloy of 0.04% Ca-1.00% Sn-0.008% Bi-residual Pb (% is mass%, hereinafter the same). It was obtained by casting a 1 mm thick lattice substrate in which a large number of orthogonal vertical lattices 1 and horizontal lattices 2 were surrounded by a frame lattice 3. 4 is an ear. A large number of lattice substrates having different effective diameters (values obtained by dividing four times the polygonal area by the perimeter of the polygon) as 1, 2, 4.5, 6.5, 10, 15 mm were cast. . These cast lattice substrates were heat-treated at 100 ° C. for 1 hour, age-cured, and then applied and filled with a known positive electrode active material paste. The active material paste is normally filled so that the vertical and horizontal lattices of the lattice substrate are not exposed, but may be filled so that a part of the active material paste is exposed. Next, the electrode plate filled with the active material paste was aged in an atmosphere of a temperature of 40 ° C. and a humidity of 95% for 24 hours and then dried to obtain a positive electrode plate. This is laminated with a negative electrode plate manufactured by a known method and a polyethylene separator, accommodated in a battery case, covered, and diluted with sulfuric acid having a specific gravity of 1.2 as an electrolytic solution to form a battery case. A liquid lead-acid battery having a time rate capacity of 40 Ah was manufactured. This lead storage battery was charged and discharged 1000 times at an ambient temperature of 75 ° C. according to the light load life defined in JIS D5301. Thereafter, the lead storage battery was disassembled, the positive electrode plate was taken out, and the elongation of the lattice substrate was measured.

  For comparison, a conventionally known 0.60% Ca-1.00% Sn-0.020Al-residual Pb alloy was used to cast a 1 mm-thick lattice substrate in the same manner, while varying its effective diameter. Then, using this as a positive electrode, a liquid type lead-acid battery was manufactured. Similarly, charging and discharging were repeated 1000 times at an ambient temperature of 75 ° C. according to JIS D5301, and then disassembled, and the elongation of the grid substrate of the positive electrode plate was measured.

  The results are shown in FIG. The vertical axis represents the elongation and the horizontal axis represents the effective diameter. As is clear from this figure, the lattice substrate of the product of the present invention has a lower elongation than any of the comparative products. Further, the product according to the present invention had the lowest elongation when the effective diameter of the cell was in the range of 2 to 10 times the thickness. This is presumably because the lattice substrate itself has little elongation due to corrosion, and the effective diameter of the grid has increased, so that the effect of expansion and contraction due to charging / discharging of the active material has been alleviated.

  On the other hand, when the comparative conventional alloy was used, the elongation was higher than that of the product of the present invention, and the increase in elongation became significant when the effective diameter of the squares was more than twice the thickness. This is presumably because the elongation due to corrosion of the substrate itself has greatly overcome the relaxation effect on the expansion and contraction of the active material due to the increase in the effective diameter of the grid.

  This result shows that the composition of each component of lead alloy is almost the same in the range of Ca 0.02 to less than 0.05%, Sn 0.4 to 2.5% and Ba 0.002 to 0.014%. There was no. Further, even if one or more elements are added in the range of 0.005 to 0.07% Ag, 0.01 to 0.10% Bi, and 0.001 to 0.05% of Tl, almost no results are obtained. There was no change and good results were obtained. Even if inevitable impurities are contained in the lead alloy, the result is similarly good.

  As described above, the product of the present invention can reduce the elongation of the lattice substrate, and when the elongation equivalent to the conventional one is sufficient, the effective diameter of the grid can be increased from several times to several tens of times the thickness of the lattice substrate, so The lattice spacing can be made coarse, and the weight of the lattice substrate can be reduced accordingly.

  If the effective diameter of the grid is 1 times the thickness of the grid substrate, the mass of the substrate becomes relatively large and an effect on weight reduction cannot be expected. Therefore, the effective diameter of the grid is 2 times the grid substrate thickness. More than double is required.

Front view of a lattice substrate according to an embodiment of the present invention Figure of elongation characteristics of lattice substrate after charge / discharge

Explanation of symbols

1 Vertical lattice 2 Horizontal lattice 3 Frame lattice

Claims (4)

Calcium 0.02% to less than 0.05% by weight, tin 0.4% to 2.5% by weight, barium 0.002% to 0.014% by weight, the balance being lead and inevitable impurities In the lattice substrate made of the lead-based alloy, the effective diameter of the lattice of the lattice substrate (a value obtained by dividing four times the area of the polygon by the perimeter of the polygon) is at least twice the thickness of the lattice substrate. Characteristic grid substrate for lead acid battery Lead-based alloy is further 0.005 mass% to 0.07 mass% silver, 0.01 mass% to 0.10 mass% bismuth, 0.001 mass% to 0.05 mass% thallium. The lead substrate for a lead-acid battery according to claim 1, comprising at least one element selected from the group consisting of: The grid substrate for a lead storage battery according to claim 1 or 2, wherein an effective diameter of the grid of the grid substrate is not less than 2 times and not more than 10 times the thickness of the grid substrate. A lead-acid battery using the grid substrate for a lead-acid battery according to any one of claims 1 to 3.

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