JP3780396B2 - Oil-immersed equal-pressure storage battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oil-immersed uniform pressure storage battery that is used under a high pressure such as in the deep sea, and more particularly to an oil-immersed equal pressure storage battery that can keep the amount of heat generated during charging low.
[0002]
[Prior art]
As a battery used under a high pressure such as in the deep sea, there is an oil-immersed uniform pressure type storage battery. This storage battery is generally charged under atmospheric pressure, and is used as a power source for measuring equipment under a high pressure such as in the deep sea or a power source for driving an underwater vehicle.
Such a storage battery is disclosed in JP-A-49-85530 and JP-A-49-85531 by the same applicant as the present application. As shown in FIG. 12 (A), the outline is that a plurality of open unit cells 3, 3,... (Unit cell group) are formed in a sealed space formed by the battery storage tank 1 and the pressure equalizing device 2. ) And insulating oil, and the pressure equalization of the pressure equalization group of the unit cells is achieved collectively.
[0003]
FIG. 12B is a diagram showing the internal structure of the pressure equalizing device 2, and in this example, the expansion / contraction body 8 made of a rubber bag, which is a bellows type expansion / contraction section, is a pressure equalizing function member. In this figure, the seawater introduction hole for introducing seawater into the outer periphery of the rubber bag expansion / contraction body 8 of the pressure equalizing device 2 is omitted, but a deep-sea research ship equipped with this oil-immersed pressure equalizing type storage battery has dived. When the seawater flowing into the pressure equalizing device 2 through the seawater introduction hole compresses the expansion / contraction body 8 made of rubber bag, the external pressure of the battery storage tank 1 and the pressure inside the battery storage tank 1 are balanced. Therefore, damage to the storage battery in the deep sea is prevented. The unit cell 3 is also provided with pressure equalizing means, but its configuration and the gist of the present invention are not directly related to each other, and the description thereof is omitted.
[0004]
A typical application of oil-immersed equal-pressure storage batteries is power supplies for deep-sea research vessels. This deep-sea research vessel is put into practical use under the name of “Shinkai 2000” or “Shinkai 6500”. For this, a silver zinc oxide secondary battery is used as a single battery, and the approximate specifications of the single battery are a rated capacity of 450 to 540 Ah, a weight of 9 to 9.5 kg, a size of about 110 × 90 × 430 mm, and a weight energy. -It is said that the density is 75 to 85 Wh / Kg, and the volumetric energy density is 160 to 200 Wh / l (liter). Several tens of such cells are arranged in the battery storage tank.
[0005]
As is well known, in oil-immersed equal-pressure storage batteries for such applications, weight efficiency and volumetric efficiency are given the highest priority, as well as cycle life and discharge performance. Conventionally, from the viewpoint of increasing weight efficiency and volumetric efficiency, as shown in JP-A-49-85530 and JP-A-49-85531, in order to reduce unnecessary spaces in the battery storage tank as much as possible and to reduce unnecessary members. As shown (these are shown in FIG. 12), the cells were accommodated adjacent to each other.
FIG. 13 is a view showing a conventional cell storage method, and is a cross-sectional view taken along the line Y-Y in FIG. As shown in this figure, cells 3 are arranged side by side in the battery storage tank 1, a spacer 4 is attached to the wall surface of the battery storage tank 1, and a corner of the battery storage tank 1 is attached. An insulating oil moving passage 6 is provided. The insulating oil moving passage 6 is connected to the pressure equalizing device 2 and the upper space 1 a of the battery storage tank 1.
[0006]
[Problems to be solved by the invention]
Oil-immersed equal-pressure storage batteries are generally charged on the ground or on a support ship after being used (discharged) under high pressure such as in the deep sea. It is not carried out by a complicated method, but is performed while being sealed in the battery storage tank 1.
Although the cell temperature rises during charging, it is well known that excessive temperature rise has adverse effects such as separator and electrode degradation, electrolyte decomposition, etc. It is one of the important issues in this type of battery technology field. However, the conventional oil-immersed uniform pressure type storage battery that has been disposed adjacent to each other has a problem that heat dissipation characteristics are not necessarily good due to its structure.
[0007]
Conventionally, in order to deal with such problems, it is unavoidable to store oil-immersed equal-pressure storage batteries in a tent and cool them with a spot cooler, or place a lot of ice on the base of the base storage tank. The method of suppressing the temperature rise was adopted. However, these methods are still not sufficient, and as a result, it cannot be said that there are no cases where the target as originally expected in terms of cycle life and discharge characteristics cannot be achieved.
[0008]
The present invention has been made to address the above-described problems, and an object thereof is to provide an oil-immersed equal-pressure storage battery that has excellent heat dissipation characteristics and improved cycle life and discharge characteristics.
[0009]
[Means for Solving the Problems]
That is, in order to solve the above-described problems, the invention described in claim 1 includes a battery storage tank having a pressure equalizing device, a group of cells stored in the battery storage tank, and the battery storage tank. In an oil-immersed equal-pressure storage battery comprising an insulating liquid filled in the space inside,
A battery is formed between the single cell group and the inner wall of the battery storage tank and between the single battery groups so that the insulating oil in the upper space of the battery storage tank and the insulating oil in the lower space are interchanged by convection. A plurality of fluid passages communicating with the lower space and the upper space of the storage tank are formed, and the fluid passage forming member is a member whose height does not reach the electrode plate group from the upper end of the unit cell.
[0010]
Alternatively, the invention described in claim 2 is characterized in that the fluid passage forming member is a wedge-shaped body.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view showing the inside of the oil-immersed equal-pressure storage battery of the present invention, and FIG. 2 is a cross-sectional view taken along the line XX of FIG. This oil-immersed equal-pressure storage battery has a cell group (3, 3,...) Arranged in a predetermined space in a battery storage tank 1 made of, for example, titanium alloy, and a silicon oil insulating oil (hereinafter, The structure is simply filled with insulating oil. As these single cells 3, a silver zinc oxide battery is usually used. The battery storage tank 1 is provided with a pressure equalizing device 2 (similar to that shown in FIG. 12). Further, a spacer 4 made of a synthetic resin (for example, polyethylene resin) is installed along the side wall 1w of the battery storage tank 1, and between the spacer 4 (battery storage tank inner wall 1w) and the unit cell 3, and Between the single cell 3 and the single cell 3, fluid passage forming members 5, 5,... Are arranged to form predetermined spaces 10, 10,. These spaces 10 serve as fluid passages for insulating oil (hereinafter, the spaces 10 are referred to as fluid passages 10).
[0012]
As shown in FIG. 3, the fluid passage forming member 5 disposed between the battery storage tank inner wall 1w and the unit cell 3 or between the unit cell 3 and the unit cell 3 has a wedge shape. The reason why the fluid passage forming member 5 is wedge-shaped is to facilitate insertion between the unit cells 3 and the unit cells 3 and between the cell storage tank inner wall 1w (spacer 4) and the unit cells 3. However, a rod-shaped body or a plate-shaped body may be used as long as there is no trouble in mounting. The wedge-shaped fluid passage forming member 5 has a space on the side surface of the fluid passage forming member 5, so that a part of the fluid passage forming member 5 can be used as an insulating oil passage.
[0013]
As described above, by arranging the fluid passage forming member 5 between the battery storage tank inner wall 1w and the single cell 3 or between the single cell 3 and the single cell 3, a lower space is formed inside the battery storage tank 1. A large number of fluid passages 10 through which fluid (insulating oil) flows are formed between 1b and the upper space 1a, between the single cells 3 and the single cells 3, or between the battery storage tank inner wall 1w and the single cells 3. The space 1a and the lower space 1b communicate with each other through these fluid passages 10. Therefore, when a temperature difference is generated between the insulating oil in the upper space 1a and the insulating oil in the lower space 1b in the battery storage tank 1, the insulating oil in the lower space 1b rises upward through the fluid passage 10 and the cold upper space 1a. This insulating oil moves downward and causes convection to be exchanged, so that temperature rise during charging can be suppressed.
[0014]
FIG. 4 is a partial cross-sectional view showing the inside of a modified embodiment of the oil-immersed equal-pressure storage battery according to the present invention, and FIG. 5 is a cross-sectional view taken along the line XX of FIG. In this oil-immersed equal-pressure storage battery, a spacer 4 made of synthetic resin (for example, polyethylene resin) along the side wall 1 w of the battery storage tank 1, and spacers 4 a and 4 a between the unit cell 3 and the unit cell 3. (However, it is not always necessary to provide the spacer 4a between the unit cell 3 and the unit cell 3), and between the spacer 4 (battery storage tank inner wall 1w) and the unit cell 3 and A short wedge-shaped body 5 ', 5',... As shown in FIG. 6 is used as a fluid passage forming member between the single cells 3 and 3 (between the spacers 4a and 4a). The predetermined fluid passages 10, 10,... Are formed.
[0015]
A short wedge-shaped body 5 disposed between the inner wall 1w of the battery storage tank and the unit cell 3 or between the unit cell 3 and the unit cell 3 (between the spacer 4a and the spacer 4a) is shown in FIG. As shown, the height H is a wedge-shaped body that is short enough not to reach the electrode plate group from the upper end of the unit cell 3. The short wedge-shaped body 5 ′ is formed between the unit cell 3 and the unit cell 3 (between the spacer 4 a and the spacer 4 a) or the battery storage tank inner wall 1 w (the spacer 4) and the unit cell 3. This is because even if there is a difference in the width of the gap with the battery 3, it is easy to insert and can be surely inserted.
[0016]
Further, the reason why the height of the short wedge-shaped body 5 'is a wedge-shaped body having such a short height H that does not reach the electrode plate group from the upper end of the unit cell is as follows.
That is, as shown in FIG. 7, the inside of the unit cell 3 is composed of an electrode plate group 3a in which a positive electrode plate, a separator, and a negative electrode plate are alternately laminated, and lead wires 3b from each electrode plate, 3c is connected to the positive terminal 3d and the negative terminal 3e.
These single cells 3, 3,... Have a characteristic of expanding in the stacking direction of the electrode plates when charging and discharging are performed, as indicated by a two-dot chain line in FIG. If charging / discharging is repeated for a single cell, there is no single cell leading to a short circuit, but a large number of single cells 3, 3,. -When a long wedge-shaped body 5 'having the same height as those of the single cells 3 is installed and fixed between the spacer 4a and the spacer 4a) and repeated charging and discharging, a single cell leading to a short circuit is generated. There are things to do. The reason is considered that the long wedge-shaped body 5 ′ inhibits the expansion of the unit cell 3 due to repeated charge and discharge, thereby loading the separator in the unit cell 3 and causing a short circuit. Therefore, when a short wedge-shaped body 5 ′ is provided between the battery storage tank inner wall 1w and the single battery 3 or between the single battery 3 and the single battery 3, the side surfaces of the short wedge-shaped body 5 ′ and the wedge-shaped body 5 ′ are provided. Although spaces are formed in the lower portion, these spaces serve as the fluid passages 10 and spaces that allow expansion during charging and discharging, so that a short circuit can be prevented.
[0017]
In the above embodiment, the fluid passage forming member (5 or 5 ′) is provided between the unit cell group (3, 3,...) And the battery storage tank inner wall 1w or between the unit cell 3 and the unit cell 3. Arrangement to form the fluid passage 10 does not mean that the fluid passage 10 is formed between all the cells 3 and the inner wall 1w of the battery storage tank, but fluid between the inner wall 1w of the battery storage tank. There may be a single cell 3, 3,... In which the passage 10 is not formed. That is, the formation of the fluid passage 10 between the unit cell groups means that, as shown in FIG. 9, even if there is a unit cell in which the fluid passage 10 is not formed between the unit cell 3 and the unit cell 3, the electrode plate group It is only necessary that the stacking direction is not. What is important is that the insulating oil in the upper space 1a and the insulating oil in the lower space 1b of the battery storage tank 1 are taken into consideration in consideration of the size and quantity of the unit cells, the internal volume of the battery storage tank 1, the viscosity depending on the type of insulating oil, and the like. Is to appropriately design the cross-sectional area and quantity of the fluid passage 10 so that they are effectively replaced by convection.
[0018]
【Example】
As an example of the present invention, a cycle life test and a temperature rise test during charging were performed using the oil-immersed equal-pressure storage battery of the present invention and a conventional oil-immersed equal-pressure storage battery that was closely adjacently housed.
The silver zinc oxide single battery 3 used here is a prismatic battery having a bottom surface of 110 × 90 (mm ² ) and a height of 400 (mm), and has an initial capacity of 650 Ah.
In these oil-immersed equal-pressure storage batteries, the same number of cells having the same configuration was used, and both were subjected to a charge / discharge test under an environment of normal pressure (atmospheric pressure) and ambient temperature of 25 ° C. The discharge condition is “90 A constant current discharge, end-of-charge voltage of 2.05 V / single cell”. FIG. 10 is a view showing the results of the cycle life characteristic test, and FIG. 11 is a view showing a temperature change at the time of charging in the 20th cycle. The temperature change was measured with a temperature sensor attached to the bottom of the unit cell.
As is clear from these results, it is obvious that the present invention is superior in cycle life performance and in suppressing temperature rise during charging as compared to the conventional product.
[0019]
A problem with conventional oil-immersed equal-pressure storage batteries is that the battery temperature rises greatly during charging, which adversely affects battery characteristics. As a result of investigating this cause, it is difficult to release the heat generated inside the single cell to the outside of the single cell because the single cells are arranged adjacent to each other, and the insulating oil in the upper space 1a and the lower space 1b inside the battery storage tank. It has been found that the passage through which the convection of the insulating oil is satisfactorily not ensured, and the insulating oil in the lower part cannot be cooled down no matter how much the upper part of the battery storage tank 1 is cooled. Therefore, the present inventors have arranged a fluid passage forming member (5 or 5 ′) between the unit cell 3 and the inner wall 1w of the cell storage tank and at an appropriate location in the cell group, and the battery storage tank. If a plurality of fluid passages 10 that connect the lower space 1b and the upper space 1a are formed, the insulating oil in the upper space 1a of the battery storage tank 1 and the insulating oil in the lower space 1b are successfully switched by convection, and charging is performed. It has been found that the temperature rise of can be kept low.
[0020]
In the present invention, a silver-zinc oxide battery has been described as an example of the unit cell 3, but the battery characteristics are adversely affected by a temperature rise in a charging character such as a lithium battery, a nickel cadmium battery, or a nickel metal hydride battery. It goes without saying that it can be applied to all such batteries.
[0021]
【The invention's effect】
As described above in detail, according to the oil-immersed and equalized storage battery of the present invention, the insulating oil in the upper space and the insulating oil in the lower space in the battery storage tank can be effectively replaced by convection. Temperature rise can be kept low. In addition, by using a short wedge-shaped body, the unit cell can expand freely during charging and discharging, so even when a plurality of unit cells are stored in the battery storage tank, charging and discharging can be performed with the unit cell alone. This is the same state as repeated, and there is almost no risk of a short circuit. Therefore, it is possible to provide an oil-immersed equal pressure storage battery with improved cycle life and discharge characteristics.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view showing the inside of an oil-immersed equal-pressure storage battery according to the present invention.
FIG. 2 is a cross-sectional view taken along the line XX of FIG. 1 and shows a state in which a fluid passage is formed by disposing a fluid passage forming member between the single cells.
FIG. 3 is a perspective view showing an example of a wedge-shaped fluid passage forming member used in the oil-immersed equal-pressure storage battery of the present invention.
FIG. 4 is a partial cross-sectional view showing the inside of a modified embodiment of the oil-immersed equal-pressure storage battery according to the present invention.
5 is a cross-sectional view taken along the line XX of FIG. 4 and shows a state in which a fluid passage is formed by disposing a fluid passage forming member between the single cells.
FIG. 6 is a perspective view of a short wedge-shaped body of a fluid passage forming member used in the oil-immersed equal pressure storage battery of the present invention.
FIG. 7 is a cross-sectional view of a state in which a short wedge-shaped body is installed between the cells arranged in the battery storage tank of the oil-immersed equal-pressure storage battery according to the present invention.
FIG. 8 is a cross-sectional view showing the swelling of the electrode plate group in the unit cell during charging and discharging.
FIG. 9 is a plan view showing another embodiment in which a fluid passage is formed by disposing a fluid passage forming member between a single cell and a single cell inside the oil immersed equal pressure storage battery of the present invention.
FIG. 10 is a diagram showing the results of a cycle life test performed using the oil-immersed uniform pressure storage battery of the present invention and a conventional oil-immersed uniform pressure storage battery.
FIG. 11 is a diagram showing a temperature rise test result during charging performed using the oil-immersed uniform pressure storage battery of the present invention and a conventional oil-immersed uniform pressure storage battery.
FIG. 12 (A) is a partial cross-sectional view showing the inside of a conventional oil-immersed equalizing type storage battery, and FIG. 12 (B) is a view showing an outline of the inside of the pressure equalizing device.
13 is a cross-sectional view taken along the line YY in FIG. 12A, and is a view showing an arrangement state of the cell groups in the battery storage tank.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Battery storage tank 1a Battery storage tank upper space 1b Battery storage tank lower space 2 Pressure equalizing device 3 Single cell 4 Spacer 5 Fluid passage formation member 5 'Short fluid passage formation member 10 Fluid passage

Claims (2)

In an oil-immersed pressure equalizing type storage battery comprising a battery storage tank having a pressure equalizing device, a unit cell group stored in the battery storage tank, and an insulating liquid filled in a space in the battery storage tank,
A battery is formed between the single cell group and the inner wall of the battery storage tank and between the single battery groups so that the insulating oil in the upper space of the battery storage tank and the insulating oil in the lower space are interchanged by convection. A plurality of fluid passages communicating the lower space and the upper space of the storage tank are formed, and the fluid passage forming member is a member whose height does not reach the electrode plate group from the upper end of the unit cell. Equal pressure storage battery. The oil-immersed uniform pressure storage battery according to claim 1, wherein the fluid passage forming member is a wedge-shaped body.

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