JP4443163B2 - Battery case formation method for lead acid battery - Google Patents

Description

  The present invention relates to a method for forming a battery case in which a long-life lead-acid battery can be efficiently obtained.

  The electrode plate lattice of the lead storage battery is produced, for example, by filling a lead alloy lattice with a paste-like active material obtained by kneading lead powder and lead monoxide powder with dilute sulfuric acid, and aging and drying the paste. The aging drying is performed for the purpose of removing moisture from the paste-like active material, improving the strength, crystal growth of the active material, and forming a corrosion layer on the surface of the electrode plate lattice. The corrosion layer has a function of improving the chemical bonding force between the electrode plate lattice and the active material.

  The electrode plate lattice after the aging and drying is formed by alternately laminating a plurality of positive and negative plates with a separator in between, and a positive electrode group and a negative electrode of the electrode plate group are connected with leads, respectively, and accommodated in a battery case. Then, a lid is thermally welded to the opening of the battery case, dilute sulfuric acid is injected from an inlet provided in the cover, and then electricity is passed through the lead to form a battery case of the electrode plate (for example, , See Patent Document 1).

  In general, the battery case is formed by energizing a relatively large current in order to shorten the formation time, and after the reversal, the formation efficiency rapidly decreases. The method of lowering is taken.

  By the way, in recent years, a positive electrode lattice of a corrosion-resistant lead alloy has been developed for the purpose of improving battery life (Japanese Patent Application No. 2002-116593).

JP-A-11-126604 ([0012])

  However, the positive electrode plate of the corrosion-resistant lead alloy is difficult to form a corrosion layer during aging drying and has a low chemical bonding force between the positive electrode lattice and the active material. Oxygen gas, hydrogen gas from the negative electrode) was generated between the electrode plate lattice and the active material, and as a result, there was a problem that the active material was peeled off from the electrode plate lattice.

  On the other hand, when the battery case formation is performed at a low current that does not generate gas, there is a problem that the battery case formation takes a long time and productivity is lowered.

  For this reason, the present inventors examined a method for forming a corrosion layer on the surface of the electrode plate lattice of the corrosion-resistant lead alloy, and confirmed that the corrosion layer is formed by performing precharging before the battery case is formed. As a result of further knowledge and further studies, the present invention has been completed.

The invention according to claim 1 is a battery case forming method for a lead storage battery using a corrosion-resistant lead alloy made of a Pb-Ca-Sn-Ba-Al alloy or a Pb-Ca-Sn-Ba alloy for a positive electrode grid. The current density that does not exceed the gas generation potential before the formation is 3.5 to 7.1 mA per gram of the active material at the positive electrode and the current that is 4.1 to 8.3 mA per gram of the active material at the negative electrode for 10 minutes or more. It is a battery case formation method of a lead storage battery characterized by energizing and precharging in a range of 5% or less of the battery case formation time .

The invention according to claim 2 is the battery case forming method for a lead storage battery according to claim 1, wherein the corrosion-resistant lead alloy is a lead alloy to which at least one of Ag, Bi, and Tl is further added. is there.

  As described above, the present invention provides a battery that prevents the active material from being separated by the generated gas at the initial stage of battery case formation by performing a predetermined precharge before the battery case formation to form a corrosive layer on the electrode plate lattice surface. It is a tank chemical conversion method, and is applied to a lead storage battery using a positive electrode grid of a corrosion-resistant lead alloy in which a corrosion layer is not easily formed in an aging and drying process, and its life characteristics are remarkably improved. Further, by the preliminary charging, the battery case formation after the reversal can be performed satisfactorily without lowering the formation current stepwise, and the battery case formation time can be shortened. In addition, the non-conductive material produced by the reaction between the electrode plate lattice and the electrolytic solution is reduced, and the battery case can be formed efficiently under low resistance. Therefore, there is an industrially significant effect.

  The battery case forming method of the present invention performs precharging before forming the battery case to form a corrosion layer on the surface of the electrode plate lattice, thereby increasing the chemical bonding force between the plate plate lattice and the active material, This prevents the active material from being peeled off from the electrode plate lattice by the gas generated in the substrate. In this case, the gas is generated from the active material surface.

  By performing the preliminary charging, (1) the decrease in the formation efficiency after the reversal is suppressed, and it is not necessary to perform the battery case formation step by step by discharging or resting, and the battery case formation time can be shortened. (2) The effect of reducing the amount of non-conducting substance produced by the reaction between the electrode plate lattice and the electrolytic solution and enabling efficient formation of the battery case under low resistance is also obtained.

  The present invention is applied to a lead-acid battery using a positive electrode grid of a corrosion-resistant lead alloy, and the effect is manifested. Examples of the corrosion-resistant lead alloy include a Pb—Ca—Sn—Ba—Al alloy with a small amount of Ca, an alloy in which at least one of Ag, Bi, and Tl is added to the lead alloy to improve the strength. Examples thereof include a Pb—Ca—Sn—Ba alloy with a small amount of Ca, and an alloy in which the strength is improved by adding at least one of Ag, Bi, and Tl to the lead alloy.

In the present invention, the upper limit of the energization current in the precharge is a current that does not exceed the gas generation potential for preventing the active material from peeling, and the lower limit is a current that does not significantly increase the precharge time. Specifically, the positive electrode active material per 1g 3.5～7.1M A, a negative electrode as an active material 1g per 4.1~8.3m A.

In the present invention, the precharge time is specified to be 10 minutes or more because a corrosive layer may not be sufficiently formed if it is less than 10 minutes. 20 minutes or more is particularly desirable.
If the precharge time is too long, the productivity decreases, so the upper limit is preferably about 5% of the battery case formation time.

Hereinafter, the present invention will be described in detail with reference to examples.
Example 1
Four Pb—Ca—Sn—Ba—Al corrosion-resistant lead alloy electrode plates (height 53.8 mm, width 51 mm) filled with 17.6 g of a paste-like active material, and Pb—Ca—Sn—Al system Corrosion-resistant lead alloy electrode plates (height 54.3 mm, width 51 mm) and four negative electrode grids filled with 15.2 g of active material are alternately stacked with a separator interposed therebetween, and the positive electrode grids and the negative electrode grids are respectively connected by leads. The electrode group was produced by linking.

  Next, the electrode plate group is precharged for 10 minutes in various inrush currents shown in Table 1 in a 30 ° C. water tank, and then the battery is formed with an inrush current of 3.8 A. The peak value of the positive and negative electrodes at the time of battery tank formation was measured using a mercuric sulfate electrode as a reference electrode.

  In addition, inrush current without gas generation in the preliminary charging was confirmed by the following method. That is, the positive electrode plate is placed in a water bath at 30 ° C. and charged at a constant potential in increments of 1.2 V to 0.1 V, and the potential at which gas is vigorously generated is 1.5 V. The positive electrode is energized with a current of less than 1.5 V It is confirmed that no gas is generated. Similarly, the negative electrode plate is charged at a rate of -0.8 V to -0.1 V and supplied with a current of -1.1 V, and no gas is generated. It was confirmed that gas was generated at a low potential exceeding this.

  Table 1 shows precharge inrush current, time and current density of both positive and negative poles, and Table 2 shows precharge inrush current and peak values of positive and negative polarities at that time, followed by battery case formation at 3.8A. The peak value of the potential of each positive and negative electrode was shown.

In Tables 1 and 2, no. When the precharge inrush current value of No. 1 is small (Comparative Example 1) , the peak value of the potential of each positive and negative electrode can be lowered by lengthening the time. In the case of 1, the result of setting the precharge time to 20 minutes was that the peak value of the potential of each positive and negative electrode could be suppressed to a potential at which no gas was generated. In particular, no. Nos. 2 to 4 are preferable because the preliminary charging can be performed in a short period of 10 minutes, and the current density at that time corresponds to that of the first aspect of the invention. No. Nos. 5 to 8 exceeded the gas generation potential, and as comparative examples (Comparative Example 2 ), No. 5-8. 9 is shown as a conventional example (Comparative Example 3 ).

  As is apparent from Table 2, the precharge current that does not exceed the gas generation potential at the positive and negative electrodes during precharge and 3.8 A battery case formation is 0.5 A or less.

  However, the peak value of the potential at the time of 3.8A battery case formation is closer to the gas generation potential as the precharge current is smaller, and when the inrush current of precharge is 0.13A (No. 1), it is positive and negative Both exceed the gas generation potential. This is because the precharge time is short as described above, and the corrosion layer was not sufficiently formed at a low current of 0.13A. In order to solve this problem, it can be solved by lengthening the preliminary charging time, but the productivity is lowered. Therefore, it is desirable to perform the preliminary charging by energizing an upper limit current (0.5 A) that does not generate gas.

  In addition, the used lead alloy is 0.04Ca-0.1Sn-0.008Ba-0.02Al-residual Pb.

(Example 2)
The same electrode plate group as used in Example 1 was put in a 30 ° C. water tank, and a current of 0.5 A was applied to precharge it. The charging time was variously changed between 10 minutes and 1 hour.

  Next, the battery case was formed with an inrush current of 3.8 A. The peak values of the positive and negative electrodes at the time of entry were measured using a mercuric sulfate electrode as a reference electrode.

(Comparative Example 4 )
A battery case was formed by the same method as in Example 2 except that the precharge time was 5 minutes, and the peak values of the positive and negative electrode potentials were measured.

(Comparative Example 5 )
A battery case was formed by the same method as in Example 2 except that the preliminary charging was not performed, and the peak values of the positive and negative electrode potentials were measured. Table 3 shows the measurement results of Example 2 and Comparative Examples 4 and 5 .

  As is apparent from Table 3, when precharging is performed for 10 minutes or more, the peak value of the potential is sufficiently lower than the gas generation potential in both the positive and negative electrodes. In this case, the precharge time is preferably 10 minutes in order to shorten the total formation time.

(Example 3)
The same electrode plate group produced in Example 1 was connected in series with 6 cells to assemble a 12V lead acid battery, and precharging and battery formation were performed under various conditions. Thereafter, a 40 ° C. light load life test stipulated by JIS was conducted. The amount of charge / discharge electricity in the preliminary charge and battery case formation (first charge, discharge, second charge) was the same under each condition.

(Comparative Example 6 )
A battery case formation and a life test were performed under the same conditions as in Example 3 except that the preliminary charging was not performed.
Table 4 shows the life test results of Example 3 and Comparative Example 6 .

  As is clear from Table 4, the life characteristics were superior to those (No. 1-5) that were precharged (No. 6). Among them, those (Nos. 3 to 5) in which preliminary charging was performed by energizing 0.5 A (see Table 1 for current density) were particularly excellent.

  No. No. 5 is a product in which the total formation time is shortened without decreasing the formation current stepwise after the reversal. Compared with 3 and 4, it was a level comparable to that.

  The improvement in the life characteristics depends on the formation of a corrosive layer on the surface of the electrode plate lattice by precharging, and also on the reduction of non-conductive materials.

  The lead storage battery using the Pb—Ca—Sn—Ba—Al alloy for the positive electrode lattice has been described above. However, a lead alloy positive electrode lattice in which an appropriate amount of at least one of Ag, Bi, and Tl is added to the alloy is used. It was confirmed by a separate experiment that the same effect was obtained in the lead storage battery used.

  In addition to the lead alloys described above, the lead alloy has the same effect as the Pb—Ca—Sn—Ba alloy and a lead alloy to which an appropriate amount of at least one of Ag, Bi, and Tl is added. It was confirmed that When producing a lead alloy that does not contain Al, it is preferable to produce the lead alloy in a non-oxidizing atmosphere. This makes it possible to prevent disappearance of Ca due to oxidation and to easily control the amount of Ca.

  Preferred ranges for each component of the lead alloy are as follows: Ca is 0.02% by mass to less than 0.05% by mass, Sn is 0.4% by mass to 2.5% by mass, and Ba is 0.002% by mass to 0.014%. Mass%, Al is 0.005 mass% to 0.04 mass%, Ag is 0.005 mass% to 0.07 mass%, Bi is 0.01 mass% to 0.1 mass%, and Tl is 0.001. % By mass to 0.05% by mass. The effect was remarkable for alloys having these composition ranges, and the effect was particularly preferable with a lead alloy having a Ca content of less than 0.05% by mass.

Claims (2)

In a battery formation method for a lead storage battery using a corrosion-resistant lead alloy made of a Pb-Ca-Sn-Ba-Al alloy or a Pb-Ca-Sn-Ba alloy for a positive electrode grid, a gas generation potential is set before the battery formation. The current density that does not exceed is 3.5 to 7.1 mA per gram of active material at the positive electrode, and the current that is 4.1 to 8.3 mA per gram of active material at the negative electrode is 10 % or more and 5% of the battery formation time. A battery case forming method for a lead-acid battery, wherein the battery is energized and precharged in the following range . 2. The battery forming method for a lead storage battery according to claim 1, wherein the corrosion-resistant lead alloy is a lead alloy to which at least one of Ag, Bi, and Tl is added.