JP2013084362A - Lead battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve charge acceptance performance, high rate discharge performance and idling stop life performance of a lead battery with a separator comprised of a porous sheet and a glass mat.SOLUTION: The lead battery includes a separator composed of a porous sheet and a glass mat as a separator, and electrolyte contains aluminum ions of 0.02 mol/L-0.2 mol/L inclusive and lithium ions of 0.02 mol/L-0.2 mol/L inclusive. Thus, the lead battery is excellent in charge acceptance performance, high rate discharge performance and idling stop life performance and has little falling of a cathode active material.

Description

  The present invention relates to a lead storage battery including a separator made of a porous sheet and a glass mat.

  A separator made of a porous sheet and a glass mat can prevent the positive electrode active material from falling off, and is therefore used in a lead storage battery for a vehicle having a large vibration such as a truck or a bus. Here, the “glass mat” refers to a mat made of glass fibers having a fiber diameter of about 20 μm as defined in SBA S 0401, which is a standard of the Battery Industry Association. In addition to this, SBA S 0406 is specified for the retainer mat, which is a glass mat with a fiber diameter of 1 μm or less, and is often used for control valve type lead-acid batteries, also called AGM or fine glass mat. This is different from the “glass mat” in In recent years, vehicles such as trucks and buses have been equipped with an idling stop function. However, a lead-acid battery equipped with a separator made of a porous sheet and a glass mat has a physical barrier to ionic conduction in the electrolyte while the glass mat prevents the positive electrode active material from falling off. In order to reduce the rate discharge characteristic, there is a problem that the idling stop life performance is insufficient.

  Prior art related here shows that Patent Document 1 (WO2007 / 036979) can improve the idling stop life performance by containing aluminum ions in the electrolyte of a lead storage battery including a polyethylene separator having micropores. It is said that the 5-hour rate capacity can be increased by containing lithium ions. However, Patent Document 1 does not mention a separator composed of a porous sheet and a glass mat. Further, according to an experiment by the inventors, even when aluminum ions or lithium ions are included in the electrolyte solution with the configuration of Patent Document 1 that does not include a glass mat, the idling stop life performance is not improved under use conditions where vibration is large. Furthermore, in a lead storage battery including a separator made of a porous sheet and a glass mat, the idling stop life performance was not improved even when the electrolyte contained aluminum ions alone.

WO2007 / 036979

  The subject of this invention is improving the charge acceptance performance, the high rate discharge performance, and the idling stop life performance of the lead acid battery provided with the separator which consists of a porous sheet and a glass mat.

  The present invention provides a lead storage battery including a positive electrode plate, a negative electrode plate, an electrolytic solution, and a separator, wherein the separator includes a porous sheet and a glass mat, and the electrolytic solution contains aluminum ions in an amount of 0.02 mol / L to 0.2 mol / L, It contains 0.02 mol / L or more and 0.2 mol / L or less of lithium ions.

  As shown in Table 1 and FIGS. 2 to 5, when a separator composed of a porous sheet and a glass mat is provided, the electrolytic solution is 0.02 mol / L to 0.2 mol / L of aluminum ions and 0.02 mol of lithium ions. When it is contained at least 0.2 mol / L, a lead storage battery excellent in idling stop life performance, charge acceptance performance, and high rate discharge performance can be obtained. Further, as shown in Table 1, the glass mat can prevent the positive electrode active material from falling off. When a separator composed of a porous sheet and a glass mat is provided, aluminum ions do not affect the performance at a concentration of less than 0.02 mol / L, and when the concentration exceeds 0.2 mol / L, the high rate discharge performance decreases, At the same time, the idling stop life performance is significantly reduced. Similarly, when a separator composed of a porous sheet and a glass mat is provided, the lithium ion does not affect the performance at a concentration of less than 0.02 mol / L, and the high-rate discharge performance decreases when the concentration exceeds 0.2 mol / L. At the same time, the idling stop life performance is significantly reduced.

Sectional drawing of the principal part of the lead acid battery of an Example Characteristic diagram showing the dependence of charge acceptance performance, high rate discharge performance, and idling stop life performance on aluminum ion concentration. Lithium ion concentration is fixed at 0.02 mol / L. Characteristic diagram showing the dependence of charge acceptance performance, high rate discharge performance, and idling stop life performance on aluminum ion concentration. Lithium ion concentration is fixed at 0.2 mol / L. A characteristic diagram showing the lithium ion concentration dependence of charge acceptance performance, high rate discharge performance, and idling stop life performance, and the aluminum ion concentration is fixed at 0.02 mol / L Characteristic diagram showing the dependence of charge acceptance performance, high rate discharge performance, and idling stop life performance on lithium ion concentration. Aluminum ion concentration is fixed at 0.2 mol / L.

  Hereinafter, an optimum embodiment of the present invention will be described. In carrying out the present invention, the embodiments can be appropriately changed in accordance with common sense of those skilled in the art and disclosure of prior art.

  A positive electrode grid was prepared by a rotary expanding method using a Pb-Ca-Sn alloy. A positive electrode active material paste was prepared from lead powder, synthetic resin fiber, water, and sulfuric acid according to a conventional method, filled in a positive electrode grid, aged and dried to obtain an unformed positive electrode plate. A negative electrode grid was prepared by a rotary expanding method using a Pb-Ca-Sn alloy. A powder containing lead powder as the main component and containing synthetic resin fiber, lignin, barium sulfate and carbon black is prepared according to a standard method, and the negative electrode lattice is filled with water and sulfuric acid as a paste of the negative electrode active material. To give an unformed negative electrode plate. Both the positive electrode lattice and the negative electrode lattice, or only the positive electrode lattice may be made of a Pb—Sb alloy. Moreover, the processing method from a lead alloy to a grating | lattice is arbitrary, the manufacturing method of lead powder, the content of lead in lead powder, the additive to lead powder, etc. are arbitrary.

  An unformed negative electrode plate was accommodated in a porous bag-like polyethylene separator, and 13 negative electrodes and 12 positive electrodes were laminated so that a glass mat was sandwiched between the polyethylene separator and the positive electrode. The laminated negative plates were connected to each other with a strap, and similarly laminated positive plates were connected to each other with a strap to form an element. Six elements are housed in series in a battery case, containing dilute sulfuric acid with a specific gravity of 1.22 at 20 ° C, aluminum ions with a concentration of 0 to 0.3 mol / L, and lithium ions with a concentration of 0 to 0.3 mol / L. The electrolytic solution was injected, and a liquid lead-acid battery of type 145G51 (nominal voltage 12V, rated 5-hour rate capacity 120Ah) was manufactured by battery case formation. The specific gravity of the electrolytic solution is arbitrary.

  Although aluminum ions were added as aluminum sulfate and lithium ions were added as lithium sulfate, the form at the time of addition is arbitrary as long as it is a compound soluble in dilute sulfuric acid such as aluminum hydroxide, lithium hydroxide, lithium aluminum dioxide and the like.

  FIG. 1 shows an essential part of a lead storage battery 2 of the embodiment, 4 is a positive electrode plate, 6 is a negative electrode plate, 8 is an example of a porous sheet made of a porous and bag-like polyethylene separator, and accommodates the negative electrode plate 6. . The thickness of the polyethylene separator 8 is, for example, 0.4 mm in the embodiment, but is arbitrary. A glass mat 10 is sandwiched between the polyethylene separator 8 and the positive electrode plate 4 and pressurizes the positive electrode plate to prevent the positive electrode active material from falling off. The glass mat 10 is a glass fiber mat having an average diameter of 20 μm and a thickness of 0.5 mm, but is optional. The polyethylene separator 8 and the glass mat 10 as a whole are called a separator made of a porous sheet and a glass mat. The polyethylene separator 8 and the glass mat 10 may or may not be bonded, and a porous sheet made of synthetic pulp may be used instead of the polyethylene separator 8. Further, the porous sheet is not limited to the bag shape, and is not limited to the one that accommodates the electrode plate. Further, the polyethylene separator 8 may house the positive electrode plate 4, and the glass mat 10 may be between the negative electrode plate 6 and the polyethylene separator 8. The positive electrode plate 4 to the glass mat 10 are immersed in the electrolytic solution.

  A structural difference from a normal liquid lead-acid battery is that a glass mat 10 is used in addition to the polyethylene separator 8 in order to prevent the positive electrode active material from falling off. When the glass mat 10 is provided, ion conduction in the electrolytic solution is hindered, and as a result, charge acceptance performance and high rate discharge performance are degraded.

  As a comparative example of the separator, a lead storage battery having an electrolyte containing aluminum ions or lithium ions but having no glass mat 10 and having only a polyethylene separator 8 was produced. Each produced lead acid battery has the same material and manufacturing conditions except for the aluminum ion concentration and lithium ion concentration in the electrolyte and the presence or absence of a glass mat.

  Using three lead storage batteries for each electrolyte composition, a charge acceptance test of JIS D 5301: 2006 9.5.4b) and a high rate discharge characteristic test of 9.5.3b) were performed. In addition, the idling stop life test specified in 9.4.5 of the Battery Industry Association Standard SBA S 0101: 2006 was changed to a load corresponding to a lead-acid battery for large vehicles. In this test, a charge / discharge test device was used, and a cycle consisting of 90A x 59 seconds and 600A x 1 second discharge, and a charge voltage of 14V and a maximum charge of 180A for 60 seconds was performed. When the voltage was less than 7.2V, it was considered the life. During charging and discharging, a vibration with a frequency of 2 Hz and an amplitude of 5 cm was applied to the lead storage battery in a direction perpendicular to the electrode plate surface, and the vibration applied to the lead storage battery by a truck, bus, or the like was simulated. Then, the battery that reached the end of its life was disassembled, the mass of the positive electrode active material was measured, and the dropout rate of the positive electrode active material was measured from the difference from the active material mass obtained separately before the test.

  The results are shown in Table 1. The results when the lithium ion concentration was fixed at 0.02 mol / L or 0.2 mol / L are shown in FIGS. 2 and 3, and the aluminum ion concentration was fixed at 0.02 mol / L or 0.2 mol / L. The results are shown in FIGS. The result shows the average value of three storage batteries, using a separator made of a porous sheet and a glass mat, and the result of the comparative storage battery No. 1 in which the electrolytic solution does not contain aluminum ions or lithium ions is 100%. The result is shown as a relative value.

  As shown in FIG. 2, in an electrolyte containing 0.02 mol / L lithium ions, 0.01 mol / L aluminum ions do not affect the performance. When the aluminum ion concentration is 0.02 mol / L or more, the charge acceptance performance is improved, and at the same time, the idling stop life performance is remarkably improved. However, when aluminum ions having a concentration exceeding 0.2 mol / L are present in the electrolyte, the high rate discharge performance is remarkably lowered, and at the same time, the idling stop life performance is remarkably lowered. When the aluminum ion concentration is in the range of 0.02 mol / L or more and 0.2 mol / L or less, the idling stop life performance is high and the charge acceptance performance is also high. In this range, the high rate discharge performance is also stable at a high value.

  Even if the lithium ion concentration is fixed at 0.2 mol / L (FIG. 3), the result is similar to that when fixed at 0.02 mol / L (FIG. 2). In Table 1, the No. 4 battery in which the lithium ion concentration and the aluminum ion concentration are both 0.1 mol / L shows performance similar to that expected from FIGS. 2 and 3 and Table 1, it can be seen that the aluminum ion concentration needs to be 0.02 mol / L or more and 0.2 mol / L or less.

  When the aluminum ion concentration is fixed at 0.02 mol / L and the lithium ion concentration is changed in the range of 0 to 0.3 mol / L (Fig. 4), there is no change in performance between the lithium ion concentration of 0 and 0.01 mol / L. . However, when the lithium ion concentration is 0.02 mol / L or more, it can be seen that the high rate discharge performance and the idling stop life performance are remarkably improved. The high-rate discharge performance and idling stop life performance improve with the concentration of lithium ions up to 0.2 mol / L, but at 0.3 mol / L, the high-rate discharge performance decreases significantly and at the same time the idling stop life performance It drops significantly.

  Even if the aluminum ion concentration is fixed at 0.2 mol / L (FIG. 5), the result is similar to that when it is fixed at 0.02 mol / L (FIG. 4). That is, when the lithium ion concentration is 0.02 mol / L or more, high rate discharge performance and idling stop life performance are remarkably improved, and high performance is obtained until the lithium ion concentration exceeds 0.2 mol / L. When the lithium ion concentration exceeds 0.2 mol / L, the high rate discharge performance and the idling stop life performance are significantly deteriorated. 4 and 5 and Table 1, it can be seen that the lithium ion concentration needs to be 0.02 mol / L or more and 0.2 mol / L or less.

  In Table 1, in No.1, 11, 13 storage batteries whose electrolyte does not contain lithium ions, the charge acceptance performance is improved by aluminum ions, but the high rate discharge performance is rather lowered, and the idling stop life performance is also lowered. I understand. In No.1, 7, and 8 storage batteries in which the electrolytic solution does not contain aluminum ions, lithium ion improves the high-rate discharge performance, but the idling stop life performance is only slightly improved.

  The storage batteries of Nos. 19 to 22 in Table 1 do not include a glass mat, but include only a polyethylene separator. Compared to a storage battery with a separator made of a porous sheet and a glass mat with an electrolyte of the same composition, the high rate discharge performance is high, but the idling stop life performance is low, and the positive electrode active material is removed after the idling stop life test. It can be seen that the rate is high. In addition, when comparing storage batteries with only a polyethylene separator without a glass mat, idling stop compared to storage batteries that do not contain lithium ions but contain only aluminum ions but do not contain lithium ions or aluminum ions. Life performance is improved (No. 19 and 20 in the comparative example).

  In the Example, the lead storage battery which is provided with the separator which consists of a porous sheet and a glass mat, and was excellent in charge acceptance performance, high-rate discharge performance, and idling stop life performance is obtained. In addition to aluminum ions and lithium ions, the electrolytic solution may contain, for example, sodium ions, potassium ions, magnesium ions or the like having a concentration of 0.02 mol / L or less.

2 Lead acid battery 4 Positive electrode plate 6 Negative electrode plate 8 Polyethylene separator 10 Glass mat

Claims (1)

In a lead storage battery comprising a positive electrode plate, a negative electrode plate, an electrolyte and a separator,
The separator is composed of a porous sheet and a glass mat,
The lead acid battery, wherein the electrolytic solution contains aluminum ions in an amount of 0.02 mol / L to 0.2 mol / L and lithium ions in an amount of 0.02 mol / L to 0.2 mol / L.

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