JP2003346891A - Lead-acid battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lead-acid battery avoiding an active material from sticking to a tab part protruding from the grid body and formed with a superior joint part between the tab part and a connecting body in the lead-acid battery using the expanded grid body formed by treating a lead alloy sheet. <P>SOLUTION: In this lead-acid battery using the expanded grid body formed by treating the lead alloy sheet on a positive plate or a negative plate, when the thickness of the plate using the expanded grid body is set to T and the thickness of the lug part, or a power collection part, is set to t, then the ratio T/t is 1.0-1.5. <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 storage battery.

[0002]

2. Description of the Related Art In general, a lead-acid battery using an expanded grid formed by processing a lead alloy sheet made of a Pb-Sn-Ca-based alloy uses a conventional cast-type grid made of a Pb-Sb-based alloy. Compared to the lead storage batteries used, they have advantages such as excellent liquid reduction characteristics and storage characteristics, and are widely used. Although a cast lattice made of the same Pb-Sn-Ca-based alloy is also used, the expand type is superior to the cast type in terms of productivity.

[0003]

However, when an expanded grid is used, when the grid is filled with the paste-like active material in the manufacturing structure of the electrode plate, the active material protrudes from the grid to collect current. It has become clear that it adheres to the lug, which is a part, and has an adverse effect on welding with a connector made of a lead alloy in a subsequent assembly process. That is, if the active material adheres to the surface of the electrode lug, a gap may be formed at the interface between the welded connector and the lug, which promotes the progress of corrosion in this region and reduces the battery life. It has been found that this causes disconnection of the connection part.
Regarding the positive electrode plate, when the battery is left open for a long period of time, corrosion progresses at the interface between the ear and the connector, and the life after that may be shorter than that of the battery not left unattended. Also, regarding the negative electrode plate, when the liquid reduction accompanying the use of the battery progresses and the electrode plate ears are exposed from the electrolyte surface,
Corrosion is promoted.

[0004] On the other hand, such a problem is hardly observed in the case of a cast-type lattice body made of the same lead alloy. The reason is that the cast lattice has a thickness of the outer frame bone equal to the thickness of the electrode plate. It can be considered that there is almost no adhesion to the ears due to the active material protruding from the lattice.

[0005] However, in the case of an expanded lattice, a lead alloy sheet having a uniform thickness is generally processed and formed into a lattice. However, since the thickness of the lattice frame is the same as the thickness of the lug, the active material is not used. When filling in the lattice body, the active material may protrude beyond the frame bones and reach the ears in some cases. This cause adversely affects the welding of the ear and the connector as described above, and thus promotes the progress of corrosion in this portion.

[0006]

In order to solve such a problem, a lead-acid battery using an expandable grid formed by processing a lead alloy sheet on a positive electrode plate or a negative electrode plate is provided. In the electrode plate using the lattice body of the formula, when the thickness of the electrode plate is T and the thickness of the ear portion which is a current collecting portion is t, the ratio T / t is 1.0 to 1.5.
It is assumed that.

Further, in the lead storage battery having the structure of the first aspect, it is preferable that the grid body uses a rotary expanded grid.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a lead-acid battery 1 of the present invention comprises a positive electrode plate 2, a negative electrode plate 3 and a separator 4. Both the positive electrode plate and the negative electrode plate are of a rotary expandable type. It uses a grid body and is welded to the connecting body 6 at the ears 5 of the electrode plate. FIG. 2 shows a cross section of the electrode plate as one embodiment of the present invention. The thickness T of the electrode plate in a state where the grid 7 is filled with the active material 8 is 1.
3 mm, the thickness of the negative electrode plate is 1.0 mm, and the thickness t of the ear 5 of the electrode plate is 1.0 mm for the positive electrode plate and 0.8 mm for the negative electrode plate. That is, the ratio T / t is set to 1.0 to 1.5 for both the positive and negative electrodes.
This is the configuration. The present invention is effective even when the ratio T / t is set to 1.0 to 1.5 in either one of the positive and negative electrode plates, and the expanded lattice body can be formed by a reciprocating method.

[0009]

EXAMPLES The battery according to the embodiment of the present invention as described above and the battery according to the conventional example were manufactured and tested and evaluated.

FIG. 3 schematically shows a method of manufacturing an electrode plate. Pb
After slitting the lead sheet 9 made of the -Ca-Sn alloy by using a rotary cutter 10, the continuous mesh-like lattice body 11 is formed by widening the lead sheet in the width direction. Here, the continuous lattice is made to have a uniform predetermined thickness at the mesh portion by passing between a pair of upper and lower rollers or the like. After that, the active material paste 12 is filled in the lattice,
The electrode plate 13 was formed by cutting into an arbitrary shape.
The same manufacturing method is used for both the positive electrode plate and the negative electrode plate. Next, as shown in FIG. 1, the lugs 5 of the electrode plate and the Pb-
An electrode group is formed by welding the connection body 6 of the Sn alloy,
Various lead-acid batteries for automobiles of the 55D23 type were prepared as shown in Tables 1 and 2.

[0011]

[Table 1]

First, as shown in Table 1, the life of the seven batteries after standing was confirmed. That is, after the battery is left open for 6 months in an atmosphere of 40 ° C. from the initial charge of the battery,
A light load life test described in JIS D5301 at 75 ° C. was performed. As a result, when the ratio T / t when the thickness of the positive electrode plate was T and the thickness of the ear portion 5 was t exceeded 1.5, the life was reduced. A detailed analysis of the end-of-life battery reveals that, in the case of a battery with a ratio T / t of more than 1.5, corrosion progresses at the joint between the lug of the positive electrode plate and the connector when the battery exceeds 1.5. It is considered that the difference in life is due to this point. In addition, as a result of observing the joint portion between the positive electrode ear portion and the connection body of the new battery before being left, when the ratio T / t exceeds 1.5, there are many gaps in the joint portion, and the ear portion has a large gap. Lead oxide was observed on the surface. This is considered to be an active material attached to the ears at the time of manufacturing the electrode plate. Further, when the battery was analyzed in a state where the battery was left open for 6 months in a 40 ° C. atmosphere, the ratio T / t was 1.5% at this time.
In the case of exceeding, corrosion progress was observed at the joint between the ear and the connector.

[0013] As described above, when the ratio T / t of the thickness of the positive electrode plate to the thickness of the ear portion is set to 1.5 or less, the adhesion of the active material to the ear portion is suppressed, so that the ear portion due to long-term storage is reduced. It is possible to suppress the progress of corrosion at the joint of the connection body.

[0014]

[Table 2]

Next, as shown in Table 2, an overcharge life test was performed on the six types of batteries. Specifically, 75 ° C
In an atmosphere, constant voltage charging at 14.8 V was performed at 144
After the continuous time, 300 A discharge was performed, and this was repeated as one cycle.
The time when the voltage becomes less than 2 V is determined as the life. The battery which reached the end of its life was disassembled and its internal deterioration was confirmed.
As a result, when the ratio T / t when the thickness of the negative electrode plate is T and the thickness of the ear portion is t exceeds 1.5, the life is shortened. This was due to the progress of corrosion at the joint of the connector and the connector. That is, when the ratio T / t exceeds 1.5, the rate of progress of corrosion increases. Similarly to the above-mentioned positive electrode plate, in the negative electrode plate, a battery having a ratio T / t exceeding 1.5 has many gaps at the joint portion between the ear portion and the connection body, and lead on the surface of the ear portion. Oxide was observed, and it was clear that the active material attached to the ears had an adverse effect.

As described above, in any of the positive and negative electrode plates, the ratio T / t when the thickness of the electrode plate is T and the thickness of the ear portion is t is 1.5 or less, so that the grid body It is thought that the active material is prevented from sticking out to the ear part by preventing the active material from protruding and forming an excellent joint between the ear part and the connector, which has an effective effect on the final battery life. Can be

In the battery of the above embodiment, both the positive and negative electrodes are made of an expanded grid, but even if one of the electrodes is made of a cast grid,
The same effect can be obtained by setting the ratio T / t to 1.5 or less in the other electrode plate.

[0018]

As described above, according to the present invention, in a lead-acid battery using an expanded grid formed by processing a lead alloy sheet on a positive electrode plate or a negative electrode plate, the active material from the grid is reduced. It controls the protrusion and avoids sticking to the ear,
An excellent joint between the ear and the connector is formed, so that the battery life is not shortened.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a general lead-acid battery

FIG. 2 is a sectional view showing the configuration of the electrode plate of the present invention.

FIG. 3 is a view schematically showing a method for manufacturing a general expanded grid electrode plate.

[Explanation of symbols]

1 Lead storage battery 2 Positive electrode plate 3 Negative electrode plate 4 separator 5 Ears of the plate 6 Connected body 7 lattice 8 Active material 9 Lead alloy sheet 10 Rotary cutter 11 A continuous mesh grid 12 Active material paste 13 plates

Continuation of front page    F-term (reference) 5H017 AA01 CC05 HH01 HH03                 5H022 AA01 CC19                 5H028 CC00 HH01 HH05                 5H050 AA07 BA09 DA04 FA02 HA01                       HA04

Claims (2)

[Claims] 1. A lead-acid battery using an expanded grid formed by processing a lead alloy sheet on a positive electrode plate or a negative electrode plate, wherein the electrode plate using the expanded grid is an electrode plate. When T is the thickness and t is the thickness of the ear portion which is a current collecting portion, T / t is 1.0 to 1.5.
A lead-acid battery characterized by the following. 2. The lead-acid battery according to claim 1, wherein the grid is a rotary expanded grid.