JPH07105942A - Lead-acid battery - Google Patents

Abstract

PURPOSE:To prevent contacting of a positive and a negative electrode plate due to its (their) curving and also slipping-off of the active material from electrode plate by eliminating corrosive elongation of a lattice for electrode plate when the battery is in service, and thereby precluding the center of electrode plate from curving in bow in such a way as protruding. CONSTITUTION:A lattice for electrode plate is composed of surrounding frame bones 3, consisting of longitudinal frame bones 1 and transverse frame bones 2, and grating bones crossing longitudinally and transversely within the surrounding frame bones. At least the lattice for positive electrode plate is so structured that the section area of the lefthand and the righthand longitudinal frame bone is smaller than the section area of each grating bone extending longitudinally.

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, and more particularly to an improvement of the frame bone and lattice bone of its lattice.

[0002]

2. Description of the Related Art A lead storage battery uses an electrode plate in which a grid body made of a lead alloy, for example, a cast grid body, is filled with an active material paste prepared by kneading lead powder, dilute sulfuric acid, water and the like.

As shown in FIG. 3, the cast lattice body has a peripheral frame bone 3 composed of a vertical frame bone 1 and a horizontal frame bone 2, and a peripheral frame bone 3 thereof.
A plurality of vertical lattice bones 4 and horizontal frame bones 5 that intersect vertically and horizontally inside the
And the ears 6 are provided on the horizontal frame bone 2 above the lattice.

Further, as shown in FIG. 4 which is a cross section taken along line AA 'in FIG. 3, the cross-sectional area of the vertical frame bone 1 of the lattice is formed to be larger than the cross-sectional area of the lattice bone 4 in the vertical direction. ing.

[0005]

However, the positive electrode plate using the above-mentioned lattice has the following problems when the battery is used.

That is, as the battery is used, the positive electrode grid body is corroded, and the grid body extends in the vertical and horizontal directions. At this time, the lateral extension of the lattice bone surrounded by the frame bones was restricted by the vertical frame bones having a larger cross-sectional area than the lattice bones present at the left and right ends. Therefore, the lattice bones could not extend in the lateral direction any more, and the positive electrode plate was curved in a bow shape so that the central portion thereof protrudes, as shown in the side view of the positive electrode plate after the progress of corrosion.

The curved positive electrode plate pierces the separator and comes into contact with the negative electrode plate to cause an internal short circuit.
Due to the bending of the positive electrode grid, the adhesion between the grid and the positive electrode active material is reduced, and the active material falls off, resulting in a decrease in capacity.

The present invention solves these problems, and prevents the lattice from curving in a bow shape so that the central portion thereof protrudes when the lattice is corroded and stretched when the battery is used. It is intended to provide a lead storage battery capable of preventing the internal short circuit of the positive and negative electrode plates and the dropping of the active material from the electrode plate due to the cause.

[0009]

In order to solve the above-mentioned problems, the lead-acid battery of the present invention has a peripheral frame bone composed of a vertical frame bone and a horizontal frame bone, and intersects vertically and horizontally within the peripheral frame bone. The grid body includes a plurality of grid bones, and at least the grid body of the positive electrode plate has a cross-sectional area of the left and right vertical frame bones smaller than a cross-sectional area of the grid bones in the vertical direction.

[0010]

In the lead acid battery of the present invention, the cross-sectional area of the vertical frame bone of the grid body is smaller than the cross-sectional area of the vertical grid bone even when the grid body forming the positive electrode plate is corroded and stretched when the battery is used. The lateral extension of the lattice bone is not restricted by the left and right vertical frame bones.

Therefore, in the lattice body of the present invention, the lattice bone can further extend in the lateral direction as compared with the conventional lattice body,
It is possible to prevent the central portion of the lattice body from curving in a bow shape so as to project.

Therefore, it is possible to prevent the curved positive electrode plate from breaking through the separator and positively contacting the negative electrode plate to cause an internal short circuit, or to prevent the active material from dropping from the lattice member due to the bending of the lattice member and lowering the capacity. can do.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a side view of the lead-acid battery grid of the present invention. As shown in FIG. 1, a lead-antimony (Pb-Sb) alloy containing 2.7% by weight of antimony (Sb) was used to produce a cast grid body having a veneer size of 113 mm in height and 137 mm in width.

As shown in the cross-sectional view of FIG. 2, the lattice body has a cross-sectional area of the left and right vertical frame bones 1 of 2.5 mm ² and a cross-sectional area of each lattice bone 4 in the vertical direction of 2.8 mm ^2. And

For comparison, as shown in FIGS. 3 and 4, a cast lattice body in which the longitudinal frame bone 1 has a cross-sectional area of 3.4 mm ² and each longitudinal lattice bone 4 has a cross-sectional area of 2.8 mm ^2. Was produced and used as a conventional cast lattice.

Next, a positive electrode plate was prepared by filling a predetermined active material paste in the cast grid of the present invention and the conventional grid, and used as the positive electrode plate of the present invention and the prior art, respectively.

Then, these positive electrode plates were wrapped in a predetermined polyethylene bag-like separator, and this was combined with a negative electrode plate to produce lead storage batteries having a nominal specification of 12V48Ah, which were used as a lead storage battery and a conventional lead storage battery, respectively.

An overcharge test was conducted using these batteries. This test was carried out at 40 ° C. at a current of 5.6 A for 110 hours and then left for 48 hours, which was set as one cycle, and was performed up to 5 cycles. The bending amount of the positive electrode plate at this time was evaluated by measuring the length X (mm) in the thickness direction of the central part of the electrode plate as shown in FIG. Then, the curved state of the positive electrode plate was measured before the cycle test, after 2 cycles, after 4 cycles, and after 5 cycles, and the measurement results are shown in FIG.

As shown in FIG. 6, in the positive electrode plate of the present invention as compared with the conventional positive electrode plate, even if the lattice body corrodes and extends during charging, the lattice frames extend in the lateral direction at the left and right ends. Since it was not regulated by bone, the central portion of the lattice was not curved so as to largely project.

[0021] Then, the cross-sectional area of the vertical frame bones cast grid as S _1, the cross-sectional area of the longitudinal direction of the grating bone as S ₂ and S ₁ and a ratio S ₁ / S ₂ of S ₂ 0.5, 0 .9, 1.2, 1.
5, 1.8 and 2.0, the same overcharge test as described above was performed on the batteries using the respective grids, and the bending amount X of the positive electrode plate after 4 cycles was measured.

The results are shown in FIG. As shown in FIG. 7, when the value of S ₁ / S ₂ is 1.2 or more, the bending amount X of the positive electrode plate is 7 (mm) or more, and a part of the bag-shaped separator wrapping the positive electrode plate is broken. The positive and negative plates were in contact with each other, and a large amount of the active material was dropped from the positive plate.

On the other hand, when the value of S ₁ / S ₂ was 0.9 or less, the bending amount of the positive electrode plate was small, and the bag-shaped separator did not break or the active material did not fall off from the positive electrode plate.

However, if the value of S ₁ / S ₂ is smaller than 0.5, the thickness of the vertical frame bone becomes too thin, making it difficult to cast the vertical frame bone and retaining the active material at the left and right ends. And the active material had fallen off from the lattice.

Therefore, the value of S ₁ / S ₂ is 0.5 to 0.9.
It is preferably in the range of.

[0026]

As described above, in the lead acid battery of the present invention,
At least the positive electrode plate is composed of a peripheral frame bone consisting of a vertical frame bone and a horizontal frame bone and a lattice frame crossing in the vertical and horizontal directions in the peripheral frame bone, and the cross-sectional area of the left and right vertical frame bones is the vertical direction of the lattice frame A grid body smaller than the cross-sectional area is used.

Therefore, even if the lattice is corroded and stretched when the battery is used, the lateral extension of the lattice is not restricted by the left and right vertical frame bones, and the central portion of the lattice is projected. It is possible to suppress bending in a bow shape.

Therefore, the curved grid body pierces the separator and comes into contact with the positive and negative plates to cause an internal short circuit.
It is possible to prevent the active material from falling out of the lattice due to the bending of the lattice.

[Brief description of drawings]

FIG. 1 is a diagram showing a cast grid used in the lead storage battery of the present invention.

FIG. 2 is a cross-sectional view taken along the line A-A ′ of the same lattice body.

FIG. 3 is a diagram showing a cast grid used in a conventional lead storage battery.

FIG. 4 is a sectional view taken along line B-B ′ of the same lattice.

FIG. 5 is a side view of a curved positive electrode plate.

FIG. 6 is a diagram showing a relationship between a charge amount and a bending amount of a positive electrode plate using the present invention and a conventional cast grid.

FIG. 7 is a diagram showing the cross-sectional area of the vertical frame bones of the cast lattice and the ratio of the vertical lattice bones, and the amount of bending of the positive electrode plate.

[Explanation of symbols]

 1 Vertical frame bone 2 Horizontal frame bone 3 Surrounding frame bone 4 Vertical lattice bone 5 Horizontal lattice bone 6 Ear

Claims (2)

[Claims] 1. A polar plate comprising an active material filled in a lattice body composed of a peripheral frame bone composed of a vertical frame bone and a horizontal frame bone, and a lattice frame crossing vertically and horizontally in the peripheral frame bone, At least the positive electrode plate is a lead storage battery in which the cross-sectional area of the left and right vertical frame bones of the grid is smaller than the cross-sectional area of the vertical grid bones. 2. The lead storage battery according to claim 1, wherein the ratio of the cross-sectional area of the vertical frame bone to the cross-sectional area of the lattice bone in the vertical direction is 0.5 to 0.9.