JPS5814525Y2 - Sealed zinc alkaline storage battery - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sealed zinc-alkaline storage battery that prevents self-discharge of zinc and improves the leakage resistance of an alkaline electrolyte, and particularly relates to an improvement of its sealing member.

Until now, zinc has been used for the cathode and nickel, manganese, silver, etc. for the anode to control the amount of alkaline electrolyte to a low level, and it has been used in sealed zinc-alkaline storage batteries that allow the cathode zinc to absorb oxygen generated from the anode during overcharging. As the container, it is customary to use a metal container equipped with a safety valve, since the internal pressure of the battery during overcharging increases to 10 to 20 kg/-.

As shown in FIGS. 3 and 4, conventionally used containers consist of a cylindrical container 1 and a metal sealing plate 4 having a terminal cap 3 with a built-in safety valve 2. This can be obtained by attaching them together via a synthetic resin gasket 5 that insulates them.

In this case, the electrode terminal serves both as a sealing plate and a cylindrical container, but when zinc is used for the cathode, it has the disadvantage that when it comes into contact with these metals, it forms a local battery and self-discharges, resulting in hydrogen generation.

When the sealing plate is used as a cathode terminal, the potential of the sealing plate is kept extremely low, so the alkaline electrolyte easily penetrates the interface between the synthetic resin gasket and the sealing plate, resulting in leakage resistance. There was a problem that it was inferior to

The present invention solves these conventional problems by improving the sealing member.

That is, the present invention includes a metal sealing plate having a gas exhaust hole leading to the safety valve, and an insulating gasket attached to the periphery of the sealing plate and having a flat part along the lower surface of the sealing plate. This uses a sealing member that is crimped and integrated with a grommet-shaped caulking projection formed integrally with the sealing plate.By reducing the exposed metal surface of the sealing plate, it is possible to prevent contact with the alkaline electrolyte and between the sealing plate and the gasket. The penetration of alkaline electrolyte is reduced.

The embodiment will be explained below with reference to FIGS. 1 and 2.

In Fig. 1, 6 is a synthetic resin gasket, which is longer than conventional gaskets, and has a gas exhaust hole that runs along the bottom surface of the metal sealing plate and leads to the safety valve 7 in the center of the sealing plate. It has a flat part 9 up to 8.

A cylindrical eyelet-shaped caulking protrusion 11 is formed on the periphery of the gas exhaust hole 8 of the metal sealing plate 4 to protrude downward. Washer 1 with 14
By caulking and fixing 2, the sealing plate 4, gasket 6, and washer 12 are integrated in a liquid-tight manner.

With this structure, the only metal parts exposed inside the battery are the washers and caulking protrusions, making it possible to reduce the number of metal parts that are exposed inside the battery.

The sealing member thus formed is placed on the annular shoulder 10 formed on the container 1 and protrudes inward, and is fixed by caulking the opening end of the container inward.

Further, the cathode lead 13 whose one end is connected to the zinc cathode is connected to the lead attachment part of the washer 12, and the sealing plate 4 also serves as a cathode terminal.

A sealed nickel-zinc alkaline storage battery with a nominal capacity of 1.5 Ah was prototyped using the conventional sealing member described above and the sealing member of the present invention, and the hydrogen gas generation rate from the negative electrode zinc was measured and leakage resistance was measured. A test was conducted and a comparison was made.

A spiral electrode group consisting of a zinc cathode, a nickel anode, and a separator interposed between them is inserted into a cylindrical container 1, an anode lead led out from the electrode group is connected to the inner wall of the container, and a cathode lead 13 is inserted. was connected to the lead attachment part 14 of the washer 12 fixed by a caulking projection, and then a predetermined electrolytic solution was injected and sealed.

The battery using this conventional sealing member is designated as A, and the battery using the sealing member of the present invention is designated as B.
The hydrogen generation rate at ℃ and the time until leakage was observed from the contact area between the sealing plate and the gasket were determined.

The results are shown in the table below.

As is clear from these results, when the sealing member of the present invention is used in a zinc-alkaline storage battery, hydrogen generation is suppressed and the leakage resistance is improved compared to the conventional example.

This result shows that when the sealing plate of the present invention is used, the exposed metal part of the sealing plate is small because it is covered by the flat part of the gasket, so the contact area with the electrolyte is also small, which suppresses self-discharge and Also, because the sealing plate and the gasket are pressure-bonded at two places, the central part and the peripheral part, the alkaline electrolyte is prevented from permeating between the sealing plate and the gasket.

These effects have made it possible to reduce the loss of electrolyte in a sealed zinc-alkaline storage battery and extend its life.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts of a storage battery in an embodiment of the present invention.
FIG. 2 is an f-plane view taken along line u-n' in FIG. 1, FIG. 3 is a sectional view of a main part of a conventional storage battery, and FIG. 4 is a top view thereof. 4...Metal sealing plate, 6...Insulating gasket, 7...Safety valve, 8...Gas exhaust hole, 9...Flat part , 10... Annular shoulder portion, 11... Same cylindrical caulking projection, 12...
...Washer, 14...Lead attachment part.

Claims (1)

[Scope of utility model registration request] A metal sealing plate having a gas exhaust hole leading to the safety valve in the center and also serving as a cathode terminal, and an insulating gasket attached to the periphery of the sealing plate and having a flat part along the lower surface of the sealing plate are installed in the gas exhaust hole. A sealed zinc-alkaline storage battery comprising a sealing member integrally crimped with a washer having a downward eyelet-shaped caulking projection integrally formed on the periphery and a lead attachment portion fixed by the projection.