JP3321771B2 - Oil-immersed battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an oil-immersed secondary battery.

[0002]

2. Description of the Related Art When a battery used in seawater or the seabed, such as a submersible, has a large volume and weight, it is necessary to increase the pressure hull when installed inside the pressure hull of the submarine.
In order to use the pressure shell effectively, it is installed outside the pressure shell.

In order to use a battery in seawater, it is necessary that the battery is isolated from seawater and, at the same time, is housed in a pressure-resistant outer casing. As a method of isolating the battery from seawater and giving it pressure resistance, a part that can easily move even with a small pressure difference (hereinafter referred to as a pressure equalizer) is formed in a part of the rigid outer casing that houses the battery inside, The space between the battery and the outer case is filled with insulating oil, and the gas generated from the battery is discharged from a one-way valve attached to a part of the outer case. Such a so-called equalizing type oil-immersed battery has been put to practical use in seawater or on the seabed of submersibles and the like.

[0004] The oil-immersed battery contains a required number of cells,
Secondary batteries such as silver oxide-zinc batteries and nickel-zinc batteries have been used. As shown in FIG. 3, the structure of the unit cell is such that a positive electrode 6 (silver oxide or nickel, etc.) and a negative electrode 5 (zinc, etc.) are separated from each other by a separator 4 (synthetic resin, cellophane, etc.), and an electrolytic solution 2 ( Potassium hydroxide aqueous solution), and the upper part is filled with insulating oil 1. These components are housed in a battery case 7, and charge and discharge of the battery is performed through lead wires 3 (silver, nickel, etc.) connected to the positive electrode 6 and the negative electrode 5.

[0005]

In the oil-immersed secondary battery, since the upper part is filled with the insulating oil 1, when the water pressure is applied during dive and the level of the electrolyte drops, the upper insulating oil 1 is filled with the electrolyte. It goes down as the surface goes down. If the amount of insulating oil increases and adheres to the electrode plates 5 and 6, the portion to which the insulating oil adheres is passivated, so that the effective reaction area of the electrode plate is reduced and a predetermined charge / discharge capacity cannot be input / output. Therefore, it is a factor that limits the charge / discharge cycle life of the battery.

[0006] The lowering of the electrolyte level is caused by two things: the shrinkage of the gas inside the battery due to the above-mentioned water pressure, and the decrease in the amount of electrolyte due to the next reaction at the time of discharge.

[0007]

[0008]

According to the present invention, a step is provided in a battery case so that the sectional area of the battery case at a position above the electrode plate is larger than the position corresponding to the electrode plate, thereby reducing the amount of decrease in the electrolyte surface. In addition, it prevents the insulating oil from adhering to the electrode plate and extends the cycle life.

[0009]

FIG. 1 shows an embodiment of an oil-immersed secondary battery according to the present invention.
And FIG.

The embodiment of the present invention has a structure in which a step is provided in the battery case 7 and the cross-sectional area of the electrode plates 5 and 6 above the position corresponding to the electrode plate of the battery case 7 is larger than the position corresponding to the electrode plate. .

FIG. 1 shows a case in which the upper dimension of the battery case 7 is expanded in the width direction of the electrode plates 5 and 6, and FIG. , 6 expanded in the thickness direction.

As shown in FIGS. 1 and 2, the dimensions can be increased both in the width direction and in the thickness direction of the electrode plate, and a greater effect can be obtained by simultaneously increasing the dimensions in both directions.

Conventionally, when the amount of the electrolyte decreases by b × (c + d) or more, the electrolyte surface reaches the position of the plates 5 and 6, the insulating oil 1 adheres to the plates 5 and 6, and the effective reaction area becomes smaller. And reduced cycle life.

In the present invention, when the electrolyte 2 is filled at the upper part of the electrode plate having a large cross-sectional area, the electrolyte surface reaches the positions of the electrode plates 5 and 6 in FIG. ) + (B ×
d) It is necessary to reduce the amount of the electrolytic solution, and (a × c)
+ (B × d) − {b × (c + d)} = (ab) × c, and a larger decrease in the amount of electrolyte is allowed. FIG.
In the case of (e−f) × c, the one in which the dimensions in both directions are simultaneously enlarged is {(e × a) − (b × f)} × c. .

As a measure for increasing the amount of the electrolytic solution, there is a measure for increasing the dimensions b and f themselves. However, this involves problems such as increasing the overall weight and changing the design of the electrode plate. On the other hand, according to the present invention, the design of the electrode portion is not affected.

[0016]

As described above, in the oil-immersed secondary battery of the present invention, even if the electrolyte is reduced, the decrease in the electrolyte surface can be reduced as compared with the conventional one by changing the shape of the battery case. In addition, the present invention can provide an oil-immersed secondary battery having a long life and a stable performance by preventing the insulating oil from adhering to the electrode plate.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of an oil-immersed secondary battery of the present invention.

FIG. 2 is a sectional view showing one embodiment of the oil-immersed secondary battery of the present invention.

FIG. 3 is a cross-sectional view showing an example of a conventional oil-immersed secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating oil 2 Electrolyte 3 Lead wire 4 Separator 5 Negative electrode plate 6 Positive electrode plate 7 Battery case

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Patent Publication No. 41-18977 (JP, B1) Japanese Utility Model Publication No. 4026910 (JP, Y1) (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01M 10/04 H01M 2/02 H01M 10/32

Claims (1)

(57) [Claims] 1. An oil-immersed battery, wherein a step is provided in the battery case, and a sectional area of the battery case above a position corresponding to the electrode plate is larger than a sectional area of the battery case at a position corresponding to the electrode plate. Next battery.