JPS6266557A - Jar of lead-storage battery - Google Patents

Abstract

PURPOSE:To make the pressure applied on a set of plates distributed uniformly also to improve oxygen gas absorption on a negative plate by specifying the ratio of width to pitch of ribs which are provided on the inner surface of shorter sides and partitioning walls of a battery jar. CONSTITUTION:A battery jar 1 of a gas absorbing type lead-storage battery where oxygen gas is removed by absorbing it on negative plates is constructed by providing multiple ribs 9 which are set vertically on partitioning walls and inner surfaces of external walls of the cells at both ends. A set of plates consisting of positive plates, negative plates and mat-like separators is accommodated in the tank. The width of the ribs 9 is set in a range from 1.0 to 5.0mm and the ratio of width to pitch of the ribs is set in a range from 1:1.5 to 1:4. Group pressure is applied to the set of plates by the ribs. Therefore, pressure applied on the plates can be made uniform to prevent fall-off of active material and improve the utilization rate and service life without lowering the gas absorbing performance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a case for a lead-acid battery, particularly a case for a gas-absorbing lead-acid battery that absorbs and removes oxygen gas at the negative electrode.

Conventional gas absorption lead-acid batteries generally use a mat separator as an electrolyte holder and separator.

This type of storage battery uses a matte separator interposed between the electrode plates to limit the amount of electrolyte to a level that can be almost absorbed by the electrode plates, and the oxygen gas generated from the positive electrode is absorbed and removed by the negative electrode, returning it to water.

This type of battery is different from liquid-rich batteries (generally liquid-filled batteries) because the electrode plates are pressed by a thick mat separator, so the active material is less likely to fall off and the risk of short circuits is said to be low. It's here. However, since the ratio of the rib width to the rib pitch where the electrode plate group is pressurized by the ribs provided on the partition wall and short side wall inside the battery case is as wide as 1:6 or more,
There was a phenomenon in which the pressing force was not applied uniformly, and only the portions in contact with the ribs were pressurized.

Problems to be Solved by the Invention Therefore, uniform pressure is not applied to the electrode plates and the electrode plate group, and there are places where the active material falls off quickly during use, causing short circuits and shortening the lifespan. I kept it short. In addition, a method has been proposed in which the inner partition wall and short side walls inside the battery case are configured to be flat, thereby applying uniform pressure to the electrode plate and extending the life of the battery. However, in this method, the oxygen gas generated by the positive electrode plate during charging is absorbed and removed by the negative electrode plate, which deteriorates the function of the gas absorption lead-acid battery, which is to reduce the loss of electrolyte.

That is, since the surface of the negative picture plate at the end of the electrode plate group is covered by the flat partition wall and the short side wall, the surface that participates in the gas absorption reaction is reduced.

In addition, since a separator that also serves as an electrolyte holder is used, 'I
y. To ensure quantity, the maximum pore diameter must be 20μ or more.
The thickness also needs to be about 1.0 to 2.0 parts. On the other hand 2
If the pore size is 0μ or more, the active material can easily pass through, so the reaction area on the electrode plate is made uniform, and the electrode plate group is made to have a uniform reaction area so that electrode plate deterioration (softening and falling off of the active material) does not concentrate in one area. It was necessary to apply pressure.

The present invention solves the above-mentioned problems of conventional batteries, namely, to prevent short-circuits caused by non-uniform drop-off of electrode plate active material caused by uneven pressure applied to the electrode plates and active material permeation through the separator, and conversely, to prevent short-circuits. The purpose is to simultaneously solve the problem of a decrease in gas absorption capacity, that is, liquid loss, due to a reduction in the reaction surface that occurs in the method of applying flat pressure to the surface of the negative electrode plate at the end of the electrode plate group to prevent short circuits. It is.

A foolproof way to solve problems In order to achieve the above object, the present invention provides a positive electrode plate.

In a lead-acid battery case that houses a group of electrode plates consisting of a mat separator that also serves as a negative electrode plate and an electrolyte holder, multiple ribs extending vertically are formed inside the partition wall and the outer walls of the cells at both ends. However, the ratio of the rib width to the inter-rib pitch is 1:1.5 to 1:4.

In zero or gas absorption type lead-acid batteries, where group pressure is applied to the electrode plate group by a partition wall provided in the battery case and ribs provided inside the outer walls of the cells at both ends, the electrode plate group is reduced by absorbing gas. Since the function of lowering the liquid is required, it is necessary to expose the surface of the negative electrode plate at both ends of the electrode plate group to participate in gas absorption, so the ratio of the rib width to the bupinochi in conventional battery cases is 1. 1. However, even if the rib pitch is wide, even if it is good in terms of gas absorption, it will only partially pressurize the electrode plate and separator, and only the pressurized area will be mainly affected by the reaction. This results in a reduction in battery life. In order to prevent this, the rib width and rib pitch are appropriately configured to make it possible to use a mat type separator with a hole diameter of 2071 or more and a thickness of about 1 to 2.0 holes.

It has been found that if the ratio of the rib width to the rib pitch is designed to be smaller than 1:1.5, the gas absorption area decreases and the function as a gas absorption lead-acid battery deteriorates significantly. If the ratio of the rib width to the width of the correspondence is designed to be larger than 1=4, only the pressurizing part will be used as described above. In other words, the thickness of the positive electrode, separator, and negative electrode is the thinnest in the area pressurized by the ribs, and the electric resistance is lowered, so it is thought that current passes through this area during charging and discharging. This means that the part where it passes through or is used is most likely to deteriorate, causing the active material to fall off, and also because the separator is the thinnest, it is more likely to short-circuit. However, if the ratio of the rib width to the rib pitch is 1:4 and the ribs are designed to occupy more than 25 inches of the surface area of the electrode plate, the number of areas used by pressure will increase, and the electrode plate will be used evenly. It was found that this did not cause a short circuit. Therefore, the ratio of rib width to rib pitch was set to 1:1. It was designed within S~1:4. In addition, if the rib width is too narrow and is less than 1 deaf, the capped separator or electrode plate may be inserted into m≠1→
It is necessary to use at least one rib because it will significantly deteriorate the battery due to mechanical strength or stress concentration.If the width of the zero rib becomes six or more, the surface area involved in gas absorption will decrease, and the entire electrode plate will become uniform. It no longer participates in gas absorption, and the electrode plates are not used uniformly, resulting in deterioration. From this point of view, it is preferable to design within 5 degrees.

Example The present invention will be explained in detail below.

FIG. 1 is a longitudinal sectional view of a gas absorption lead-acid battery showing an embodiment of the present invention, in which 1 is a battery case, 2 is a lid, 3 is a terminal, and 4 is a valve. Reference numeral 6 denotes an electrode plate group consisting of a positive electrode 6, a negative electrode 7, and a bag-shaped separator 8 with a mat surrounding the positive electrode 6. 9 is a rib which is the key point of the present invention, W indicates the width of this rib 9,
P indicates the pitch between the ribs. The ribs 9 provided on the battery case 1 are constructed as follows.

The ribs 9 are vertically extending ribs provided inside the inner partition wall of the battery case and the outer walls of the cell at both ends, and each rib 9 is configured with a pitch P, and the rib width W is configured to be 1 mm to 6 mm. ing. Regarding the relationship between the rib width W and the pitch between the ribs, if the rib width W is 1, the pitch between the ribs is 1.5 to 4 times. The thickness of this mat is 1
．． 0 to 2.0, and the pore diameter is set to 20μ or more since it also serves as a liquid retainer. Figure 2 shows this battery case 1.
FIG. 2 is a partially cutaway perspective view.

The matte separator is designed with a pore diameter of 2 μm or more and a thickness of 1.0 μm, and the width W of the ribs 9 is designed to be 2 mm, and the ratio of the rib width W to the inter-rib pitch P is from 5 mm to 100% (all ribs). We prototyped 36B20 type lead-acid batteries using nine types of containers. The results of the SAE life test of these batteries are shown in FIG. 3. As is clear from FIG. 3, the performance with all ribs (100%) is better in terms of rib width/pitch between ribs. 25% or more is necessary since it decreases significantly when it becomes 26 inches or less.

In this invention, the ratio of the rib width to the pitch between ribs is 25%.
This is also the basis stipulated above. By the way, conventional storage batteries were designed to have a capacity of 20% or less.

Next, looking at the amount of liquid loss, the amount of liquid loss was measured in a room temperature constant voltage overcharge test (20°C x 15.Ov x 100H) using the above battery. As is clear from the figure, the rib width W
The liquid reduction characteristics are better if the ratio of P and the pitch P between the ribs is designed to be large. When this ratio exceeds 67%, the amount of liquid reduction increases rapidly. From this, it is necessary to design it to 67% or less. The present invention has a great effect by setting the ratio of the rib width W to the inter-rib pitch P in the range of 1:1.5 to 1:4 as described above.

Effects of the Invention As described above, the present invention provides a gas absorption type with high utilization rate and long life by appropriately setting the ratio of the rib width of the ribs provided on the inside of the short side of the battery case and the partition wall to the pitch between the ribs. lead-acid batteries can be supplied to the market. In particular, the present invention can improve the performance of sealed lead-acid batteries in fields where light weight and high utilization are required, such as for automobiles.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of a lead-acid battery manufactured using a battery case according to an embodiment of the present invention, Fig. 2 is a partially cutaway perspective view of the battery case, and Fig. 3 is a characteristic diagram thereof.・ 1...Battery case, 2...Lid, 5...
...Electrode plate group, 6...Positive electrode, 7...Negative electrode, 8.
...matte separator, 9...rib,
W: Rib width, P: Pitch between ribs. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 figure

Claims (2)

[Claims] (1) A case for a lead-acid battery that houses a group of electrode plates consisting of a positive electrode plate, a negative electrode plate, and a mat separator that also serves as an electrolyte holder. A case for a lead-acid battery, in which a plurality of ribs extending in the direction of the arrow are formed, and the ratio of the width of the ribs to the pitch between the ribs is 1:1.5 to 1:4. (2) The case for a lead-acid battery according to claim 1, wherein the rib has a width dimension of 1.0 to 5.0 mm.