JP2003346888A - Lead-acid battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable lead-acid battery by suppressing corrosion of a negative electrode tab part, suppressing increase of the liquid reduction amount, and securing charging power largely affecting the service life characteristics. <P>SOLUTION: A positive electrode member comprising a positive electrode grid, a positive electrode shelf 8, a positive pole, and positive electrode connecting body 10 is composed of lead or lead alloy substantially including no Sb. A part excluding a negative electrode grid skeleton part out of a negative electrode member comprising a negative electrode grid 6, a negative electrode shelf 7, a negative pole, and a negative electrode connecting body 9 is composed of lead or lead alloy substantially including no Sb. Either one of the negative electrode grid skeleton part or a negative electrode active material includes Sb and the content of the Sb to the amount of the negative active material is 0.001-0.1 mass%. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead-acid battery which does not particularly contain antimony (Sb) in a member constituting a positive electrode.

[0002]

2. Description of the Related Art Pb-
Although an Sb alloy was used, there were problems such as a large amount of liquid reduction and poor storage characteristics. The reason for this is that when the lead-acid battery is charged and discharged, the Sb contained in the positive electrode grid gradually increases.
Is eluted and deposited on the negative electrode, and the deposited Sb causes a reduction in hydrogen overvoltage at the negative electrode, which tends to generate hydrogen gas. When the charge and discharge of the battery are further continued, the amount of Sb deposited on the negative electrode increases, and the liquid reduction further proceeds. If water replenishment is neglected even if fluid reduction proceeds,
The negative electrode shelf and negative electrode ears are exposed from the electrolyte. Once these negative electrode members are exposed from the electrolytic solution, there is a problem that corrosion progresses rapidly, leading to a short life.

[0003]

In recent years, in order to suppress such corrosion and a short life due to the corrosion, a Pb-Ca-Sn alloy containing substantially no Sb has been used for the positive electrode grid.
Batteries with excellent maintenance-free properties have become popular. However, Pb-S containing Sb is contained in a positive electrode shelf or a positive electrode connector derived from the positive electrode shelf or the positive electrode shelf where the positive electrode plate is collectively welded.
It has been common to use b alloys.

[0004] A storage battery using a Pb alloy containing no Sb in the positive grid has a significantly reduced liquid reduction compared to a storage battery using a Pb-Sb alloy. It has been found that Sb contained in the pillars and the connector has a tendency to segregate in a portion centered on the negative electrode ear. When the negative electrode lug in which such Sb segregates is exposed from the electrolyte, there is a problem in that corrosion progresses on the surface of the negative electrode lug, and the thickness of the negative lug is reduced, thereby reducing the strength of the lug. .

[0005]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a negative electrode plate provided with a negative electrode grid composed of a grid lug and a grid frame, a grid lug, and a grid frame. A positive electrode plate provided with a positive electrode grid comprising a positive electrode grid, and a shelf for collectively welding electrode plate lugs of the same polarity, and a lead storage battery provided with a pole or a connection body derived from this shelf. The positive electrode member composed of the positive electrode pole and the positive electrode connector is made of lead or a lead alloy that does not substantially contain Sb, and the negative electrode of the negative electrode member composed of the negative electrode lattice, the negative electrode shelf, the negative electrode column and the negative electrode connector The portion excluding the lattice skeleton is made of lead or a lead alloy that does not substantially contain Sb, and either the negative electrode lattice skeleton or the negative electrode active material contains Sb, and the content of Sb with respect to the amount of the negative electrode active material is 0.1%. 00
A lead storage battery characterized in that the content is 1 to 0.1% by mass.

A lead-acid battery containing Sb, wherein the content of the Sb with respect to the amount of the negative electrode active material is 0.001 to 0.1% by mass.

According to a second aspect of the present invention, in the lead-acid battery of the first aspect, the negative electrode active material contains Sb, and the content of the Sb with respect to the negative electrode active material is 0.001% by mass or less.
It shows a lead-acid battery characterized by being 0.02% by mass.

Further, according to a third aspect of the present invention, there is provided the lead-acid battery according to the first or second aspect, wherein at least a part of the surface of the positive electrode grid in contact with the positive electrode active material contains 2% or more of Sn. It shows a lead storage battery characterized by comprising:

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A lead storage battery according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an exploded view showing an electrode group 1 constituting a lead storage battery of the present invention. The positive electrode plate (not shown) has a structure in which an active material is filled in a positive electrode lattice body composed of a positive electrode lug 1 and a positive electrode lattice bone (not shown). The positive electrode plate and the negative electrode plate 2 face each other with the separator 3 interposed therebetween.

The negative electrode plate 2 has a negative electrode lattice member 6 composed of a negative electrode lug 5 and a negative electrode lattice frame 4. The positive pole shelf 8 and the negative pole shelf 7 are formed by collectively welding ears of the same polarity, and a pole or a connection body is formed on each shelf. The example shown in FIG. 1 shows an example in which the positive electrode connection body 8 and the negative electrode connection body 9 are provided on the shelf for both the positive electrode and the negative electrode.

In the present invention, the positive ear 1, the positive grid bone,
The positive electrode shelf 8, the positive electrode connector 8, and the positive electrode pole (collectively referred to as a positive electrode member) are made of Pb or Pb substantially containing no Sb.
It is composed of b alloy. However, Sb contained as impurities of about several ppm is excluded. Since oxidation corrosion proceeds in the positive electrode, it is preferable to use a Pb-Sn alloy.

On the other hand, as for the negative electrode, the negative electrode lug 5, the negative electrode shelf 7, the negative electrode connector 9, and the negative electrode pole are made of Pb or Pb alloy substantially containing no Sb, similarly to the positive electrode member.
However, it is configured that at least one of the negative electrode grid body 6 and the negative electrode active material contains Sb. When Sb is contained in the negative electrode grid, particularly when the negative electrode grid 6 is made of a Pb-Ca alloy in a maintenance-free battery, a layer containing Sb on the surface of the Pb-Ca alloy, specifically Pb
-An Sb alloy layer is provided. When Sb is contained in the negative electrode active material, Sb is added to the raw material lead powder of the active material.

In the present invention, the amount of Sb added to the negative electrode grid 6 or the negative electrode active material is limited to the range of 0.001% by mass to 0.1% by mass based on the amount of the negative electrode active material. The lead storage battery of the present invention can be obtained by assembling according to a standard method using such an electrode plate group.

In particular, when Sb is added to the negative electrode active material, the addition amount is preferably 0.001 to 0.02% by mass based on the amount of the negative electrode active material. More preferably, at least a part of the surface of the positive electrode grid body that contacts the positive electrode active material is
It is preferable to dispose a Pb-Sn alloy layer containing at least Sn by mass.

The battery according to the structure of the present invention suppresses an increase in liquid reduction during the life cycle, which is the problem described above, and eliminates corrosion on the negative electrode, thereby contributing to excellent life performance.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An overcharge test and an overdischarge test were performed to evaluate the amount of liquid reduction, the presence or absence of corrosion of the negative electrode ear, and the charge acceptability.

The positive electrode grid of the lead-acid battery of the present invention has Pb-
Using a Ca-Sn alloy, the alloy composition is Pb-0.07% by mass Ca-1.3% by mass Sn. After this alloy (sheet 1) is rolled stepwise, it is subjected to an expanding process to form a lattice, filled with an active material paste, and filled with a positive electrode plate (P).
1) was produced. Further, a Pb-7 mass% Sn alloy (sheet 2) having a thickness of about 0.2 mm was superimposed on the sheet 1 and rolled stepwise, and thereafter a positive electrode plate (P2) was produced through the same process. On the other hand, the negative electrode plate was composed of Pb-0.07 mass% Ca-
A 0.25 mass% Sn alloy (sheet 3) was rolled in the same manner as the positive electrode, and then expanded to form a lattice.
Thereafter, the grid was filled with an active material paste containing 0.010% by mass of Sb based on the amount of the active material, and the negative electrode plate (N1) was filled.
Got. Further, Pb-2 having a thickness of about 0.2 mm
A mass% Sb alloy (sheet 4) was superimposed and rolled stepwise, and thereafter a negative electrode plate (N2) was produced through the same process. As the separator, a bag-shaped separator enclosing the positive electrode plate was prepared using a microporous polyethylene sheet having a thickness of about 0.3 mm.

Using the above two types of positive electrode plates and two types of negative electrode plates, a 55D23 type automotive lead-acid battery (12) is formed by using an electrode group consisting of five positive electrode plates and six negative electrode plates per cell.
V48Ah). Also, when forming the electrode group,
An Sb-free alloy is used for the shelf connecting the plates of the positive electrode and the connecting body connecting the cells, and the entire positive electrode is made of Sb.
Is not contained.

For comparison (according to the conventional manufacturing method), the sheet 1 was made of Pb-7 mass% S having a thickness of about 0.2 mm.
The b alloy (sheet 5) was superposed and rolled stepwise, and thereafter a positive electrode plate was produced through the same process (P0). The negative electrode plate was produced through a similar process by rolling the sheet 3 stepwise (N0). The battery having the configuration using this lattice was used as a conventional battery. Table 1 shows the detailed conditions of the battery configuration.

[0021]

[Table 1]

[Test 1] For the batteries having different configurations, a life test of the following pattern was carried out in order to evaluate the problem of liquid reduction characteristics and corrosion at the negative electrode. This life test is a test pattern assuming the use of the tendency to overcharge, and a cycle in which 13.8 V constant voltage charging is continuously performed in a 75 ° C. atmosphere for 120 hours was repeated. Further, in order to suppose a state in which the upper portion of the electrode plate was exposed from the electrolytic solution as the liquid reduction proceeded, the test was performed with the electrolytic solution reduced to the lower limit level. Thereafter, corrosion products formed on the surface of the negative electrode ear were removed, the thickness of the negative electrode ear was measured, and the ratio of the ear thickness after the test to the ear thickness in the initial state was determined as a percentage.

Table 1 shows the test results. In the life test evaluations in the table, the batteries A having the conventional configurations were compared with the batteries having the respective configurations, with the liquid reduction amount and the corrosion degree being 100.
The battery A of the conventional example contains Sb on the surface of the connecting body, shelf, and lattice at the location shown in FIG. 1 in the positive electrode, and contains Sb in the negative electrode.
b is not included. On the other hand, the battery B of the present invention
1 to C2 do not contain Sb in the positive electrode, and Sb
It is a battery of the composition containing. The results of Examples B1 and C2 of the present invention were as small as about 70 to 80% of that of Conventional Example A. Particularly, in Conventional Example A, although the liquid reduction was small in the initial stage, the liquid reduction tended to gradually increase as the cycle progressed. This is considered to be due to the fact that Sb contained in the positive electrode elutes and precipitates on the negative electrode as the cycle proceeds, and the hydrogen overvoltage is reduced to generate hydrogen gas. It is considered that although the amount of Sb deposited from the positive electrode to the negative electrode was small in the initial stage, the amount of Sb deposited gradually increased with the progress of the cycle, and the liquid reduction increased. On the other hand, in the present inventions B1 and C2, by removing Sb of the positive electrode and adding a small amount of Sb to the negative electrode in advance, it is possible to eliminate the increase in liquid reduction accompanying the progress of the cycle and to suppress the liquid reduction to an appropriate amount. Can be assumed. Further, in B1 and B2, the liquid reduction amount of B1 was slightly large. Although the reason for this is not clear, it is conceivable that B1 has a wider reaction surface area on Sb than B2 because Sb exists on the negative electrode active material.

Further, in the conventional example A, corrosion progress was observed in the negative electrode shelf and the ear, but in the examples B1 to C2 of the present invention.
Showed no corrosion at all and was in the same state as the initial state. It can be inferred that this is due to Sb contained in the positive electrode of Conventional Example A. As described above, Sb of the positive electrode elutes with the progress of the cycle and precipitates on the negative electrode. In particular, it is estimated that Sb segregates on the shelves, the plate ears, and the upper frame bone that are not covered with the active material (FIG. 2).
Shows the ears of the negative electrode plate and the upper frame bone). It is considered that as the cycle progresses, the portion where Sb segregates is exposed, and the surface is covered with a thin liquid film, and the pH increases. Then pH
It is presumed that Pb is easily dissolved by the increase, hydrogen gas is generated on Sb, Pb is dissolved on Pb to form a local battery in which lead sulfate is generated, and corrosion is progressing. In contrast, Examples B1 and C2 of the present invention do not contain Sb in the positive electrode, and therefore do not elute into the electrolytic solution and precipitate on the upper portion of the negative electrode. It is considered that corrosion did not progress because no local battery was formed, and it can be said that corrosion was prevented. Further, no difference was observed in the corrosion in the inventive examples B1 and C2. From this, it can be said that the corrosion was caused by the elution of Sb of the positive electrode and the deposition on the upper part of the negative electrode, and it is considered that no difference was observed in the battery in which the positive electrode did not contain Sb.

[Test 2] Next, a test was conducted on the assumption of overdischarge leaving, apart from the life test on the assumption of the tendency of overcharging. The test conditions were as follows: after conducting a constant current discharge at 9.6 A for 5 hours, a load of 10 W was connected in a 40 ° C. atmosphere and discharged for 14 days. Left for 14 days. Then 1
After carrying out recovery charging at 5.0 V for 4 hours, the capacity was evaluated by discharging at a rate of 5 hours. The test results are shown in (Table 1). In the test evaluations in the table, the batteries having the respective configurations were compared with the recovery capacity of the conventional example A having the conventional configuration being 100. The capacities of the inventive examples B1 and B2 were significantly lower than those of the conventional example A. By the way, the Sb layer on the surface of the positive electrode grid of the conventional example A has the effect of improving the charge acceptability described above and the effect of the passivation film generated at the interface between the grid and the active material after being left in overdischarge. The effect of alleviation is known. Therefore, it is considered that B1 and B2 were affected by the non-conductive film at the interface generated by the over-discharge standing and could not be recovered even when charged, resulting in a decrease in capacity. On the other hand, in Examples C1 and C2 of the present invention, a capacity equivalent to that of Conventional Example A was obtained. This is due to the fact that S on the surface of the positive electrode grid body in the inventive examples C1 and C2
The same effect as the Sb layer of the conventional example A can be considered for the n-layer, and it can be estimated that the influence of the generated non-conductive film at the interface is reduced.

As described above, the positive electrode does not contain Sb, and the negative electrode has Sb reduced to the amount of the negative electrode active material in portions other than the connecting body for connecting the cells, the shelf for welding the electrode plates, and the electrode plate ears. On the other hand, a lead-acid battery having a configuration containing 0.001% by mass to 0.1% by mass suppresses an increase in liquid reduction during a life cycle, which is a problem, and eliminates corrosion in a negative electrode, thereby achieving excellent life performance. It will contribute. Also, assuming the case of overdischarge, Sn is added to at least a part of the surface of the positive electrode grid body.
A lead-acid battery having the above-described configuration using a positive electrode plate on which a lead alloy layer containing at least 10 mass% is contained is desirable.

[0027]

As described above, the positive electrode does not contain Sb, and the negative electrode contains Sb.
The lead-acid battery, which contains a small amount of b with respect to the amount of the negative electrode active material, suppresses an increase in the amount of liquid reduction during the life cycle, maintains an appropriate amount of liquid reduction, and eliminates corrosion in the negative electrode and has excellent life characteristics. It is possible to have In particular, the lead storage battery having the above-described configuration using a positive electrode plate in which a lead alloy layer containing 2% by mass or more of Sn is formed on at least a part of the surface of the positive electrode grid has stable characteristics even when overdischarged. Obtainable.

[Brief description of the drawings]

FIG. 1 is a partially exploded view showing the configuration of an electrode group;

[Explanation of symbols] 1 Electrode group 2 Positive ear 3 separator 4 Negative grid lattice 5 Negative ears 6 Negative grid 7 Negative electrode shelf 8 Positive electrode connection 9 Negative electrode connector

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H01M 4/73 H01M 4/73 A F term (Reference) 5H017 AA01 AS08 AS10 CC05 EE02 HH01 HH05 5H022 AA01 BB11 CC12 CC13 CC20 EE02 5H028 BB05 CC08 EE01 HH01 5H050 AA07 AA08 BA09 CA06 CB15 DA05 EA02 GA07 HA01 HA12

Claims (3)

[Claims] 1. A negative electrode plate provided with a negative electrode grid composed of a lattice ear and a lattice skeleton, and a positive electrode plate provided with a positive electrode lattice composed of a lattice lug and a lattice skeleton. In a lead-acid battery having a shelf to be collectively welded and a pole or connector derived from the shelf, the positive electrode member composed of the positive grid, the positive shelf, the positive pole and the positive connector has substantially no lead containing Sb. Alternatively, a portion of the negative electrode member composed of a negative electrode lattice, a negative electrode shelf, a negative electrode pole, and a negative electrode connection body, except for a negative electrode lattice bone portion, is substantially made of lead or a lead alloy containing no Sb. A lead-acid battery, wherein one of the skeleton and the negative electrode active material contains Sb, and the content of Sb with respect to the amount of the negative electrode active material is 0.001 to 0.1% by mass. 2. The lead-acid battery according to claim 1, wherein the negative electrode active material contains Sb, and the content of the Sb with respect to the negative electrode active material is 0.001% by mass to 0.02% by mass. 3. The lead-acid battery according to claim 1, further comprising a lead alloy layer containing 2% or more of Sn on at least a part of a surface of the positive electrode grid in contact with the positive electrode active material.