JPH0896833A - Stacked nickel-metal hydride storage battery - Google Patents

Abstract

(57) [Summary] [Purpose] Simplification of maintenance, stabilization of battery performance,
(EN) Provided is a stacked nickel-hydrogen storage battery that can have a long life. [Structure] A non-sintered nickel electrode and a hydrogen electrode 4 are alternately laminated via a separator 7 to form a laminated electrode group 8. The laminated electrode group 8 is housed in the battery case 11. The laminated electrode group 8 includes an extension portion 7 of a separator 7 extending downward from the lower portion of each electrode.
a is provided. The inside of the battery case 11 is partitioned by a partition plate 9 so that the upper part serves as an electrode group housing chamber 12 for housing the laminated electrode group 8 and the lower part serves as an electrolytic solution housing chamber 13 for housing an electrolytic solution. The extension portion 7 a of the separator 7 penetrates the partition plate 9 and is arranged in the electrolytic solution storage chamber 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate-like non-sintered nickel electrode having nickel hydroxide powder as an active material and a hydrogen-absorbing alloy as an active material for electrochemically absorbing and desorbing hydrogen. The present invention relates to a laminated nickel-hydrogen battery in which hydrogen electrodes are alternately laminated with separators interposed therebetween.

[0002]

2. Description of the Related Art In a conventional stacked nickel-metal hydride battery of this type, nickel hydroxide powder and a binder are mixed.
Plate-shaped non-sintered nickel electrode made by kneading into a paste, filling a three-dimensional mesh Ni substrate, drying and pressing, and hydrogen storage alloy powder that reversibly stores and releases hydrogen. And a binder are mixed and kneaded to form a paste, which is filled in a three-dimensional mesh Ni substrate, dried and pressed, and nylon between these non-sintered nickel electrodes. Alternatively, they are laminated alternately through a polypropylene non-woven fabric (hereinafter referred to as a separator) to form a laminated electrode group, and the laminated electrode group is housed in a plastic battery case such as ABS or polypropylene, and the same material is used for the opening of the battery case. After sealing the battery lid by heat sealing or ultrasonic welding, pour a predetermined amount of electrolyte solution from the filling port on the battery lid, and then seal the filling port with a safety valve equipped with a rubber valve. Stacked type It had gained the Kell-metal hydride battery.

[0003]

When a plastic battery case is used for sealing like the above-mentioned laminated nickel-metal hydride storage battery, a high pressure is applied depending on the kind of the plastic and the wall thickness of the battery wall. Can not be expected to withstand airtightness.

Therefore, the laminated nickel-hydrogen storage battery using the plastic battery case is close to an open storage battery and is in a semi-sealed state. When this semi-hermetically stacked nickel-hydrogen storage battery is charged and discharged, oxygen and hydrogen gas generated during charging are discharged from the battery system, and the concentration of the electrolyte increases. Further, when the generated gas is discharged to the outside of the battery system under a relatively high pressure, the electrolytic solution is also discharged as a mist at that time, and the electrolytic solution is reduced.

When the concentration of the electrolytic solution is increased and the amount of the electrolytic solution is decreased, the internal resistance of the battery is increased and the charging / discharging performance is deteriorated. Also, in a battery without free electrolyte,
When a shortage of the electrolyte occurs, the hydrogen electrode is directly exposed to the atmosphere, the active reaction surface is oxidized, and the battery performance is significantly deteriorated.

In order to suppress these problems, it is possible to inject a large amount of electrolytic solution into the battery case in advance. However, if the amount of electrolytic solution in the battery container becomes large, the three-dimensional mesh Ni base electrode is filled. The nickel electrode active material (nickel hydroxide) or hydrogen electrode active material (hydrogen storage alloy) that has been removed easily drops off. Furthermore, the dropped active material, especially nickel hydroxide powder, floats in the electrolytic solution. There is a problem that a minute short circuit occurs and battery performance is deteriorated.

Therefore, it is necessary to set the amount of the electrolytic solution in the battery case to the minimum required amount and to supplement the shortage due to the charge / discharge cycle periodically. Further, in the case where the battery case is divided into a number of cell chambers, it is difficult to replenish an appropriate amount of electrolyte solution even if there is a difference in the lacking amount of electrolyte solution in each cell chamber.

An object of the present invention is to simplify maintenance,
An object of the present invention is to provide a stacked nickel-metal hydride storage battery that can achieve stable battery performance and long life.

Another object of the present invention is to provide a stacked nickel-metal hydride storage battery which can easily replace the electrolyte solution even if the battery case is divided into a plurality of cell chambers for accommodating the stacked electrode groups. To provide.

Another object of the present invention is to provide a laminated nickel alloy which can easily replace the electrolytic solution in the lower electrolytic solution storage chamber in the battery case.
It is to provide a hydrogen storage battery.

Another object of the present invention is to provide a laminated nickel-metal hydride storage battery which can easily form a partition plate through which a separator penetrates.

Another object of the present invention is to provide a laminated nickel alloy which can easily seal the partition plate at the penetrating portion of the separator.
It is to provide a hydrogen storage battery.

[0013]

The present invention uses, as an active material, a plate-shaped non-sintered nickel electrode having nickel hydroxide powder as an active material and a hydrogen storage alloy that absorbs and releases hydrogen electrochemically. An object of improvement is a laminated nickel-hydrogen battery in which flat-plate hydrogen electrodes are alternately laminated via separators to form a laminated electrode group, and the laminated electrode group is housed in a battery case.

In the laminated nickel-hydrogen battery according to the present invention, the laminated electrode group includes an extension portion of the separator extending below a lower portion of each electrode including the non-sintered nickel electrode and the hydrogen electrode, The inside of the battery case is partitioned by a partition plate so that the upper part serves as an electrode group housing chamber for housing the laminated electrode group and the lower part serves as an electrolytic solution housing chamber for housing an electrolytic solution, and the extension part of the separator is the partition plate. And is disposed inside the electrolytic solution storage chamber.

The present invention also provides a plate-shaped non-sintered nickel electrode having nickel hydroxide powder as an active material, and a plate-shaped hydrogen having a hydrogen storage alloy that stores and releases hydrogen electrochemically as an active material. An object of improvement is a laminated nickel-metal hydride battery in which electrodes are alternately laminated via separators to form a laminated electrode group, and the laminated electrode group is housed in each cell chamber in a battery case.

In the laminated nickel-hydrogen battery according to the present invention, each laminated electrode group includes an extension portion of the separator extending below a lower portion of each electrode including the non-sintered nickel electrode and the hydrogen electrode. , A plurality of cell chambers in which the upper portion of the battery case is a partition plate for accommodating each of the laminated electrode groups,
The lower part is partitioned so as to form a common electrolytic solution storage chamber for storing the electrolytic solution, and the extension part of the separator is arranged in the electrolytic solution storage chamber so as to penetrate the partition plate.

In these cases, the battery case may be provided with a passage for supplying the electrolytic solution from the upper part of the battery case to the electrolytic solution storage chamber.

Further, the partition plate is mainly composed of a plurality of divided pieces divided at respective positions of the separator, and the adjacent pieces of the divided pieces are connected to each other in a state where the separators are respectively passed between the divided pieces. Can be a structured structure.

The portion of the partition plate that penetrates the separator can be sealed with a sealing material.

[0020]

In this way, the inside of the battery case is partitioned by the partition plate so that the upper part becomes the electrode group accommodating chamber or a plurality of cell chambers for accommodating the laminated electrode group and the lower part is the electrolytic solution accommodating chamber for accommodating the electrolytic solution, When the extension portion of the separator of the laminated electrode group penetrates through the partition plate and is arranged in the electrolytic solution storage chamber, the electrolytic solution in the electrolytic solution storage chamber rises up the separator by the capillary tube and is supplied to the laminated electrode group.

Therefore, the laminated electrode group in the battery case is in a state where the electrolytic solution is regulated, and the nickel electrode active material (nickel hydroxide) or hydrogen electrode active material filled in the three-dimensional mesh Ni base electrode is formed. (Hydrogen storage alloy) is prevented from falling off, so it is possible to prevent a minute short circuit due to the floating of the falling active material
The battery performance can be stabilized.

In addition, the electrolyte deficient in charge and discharge is
Since it is always supplied to the laminated electrode group through the separator, it is possible to prevent a shortage of the electrolytic solution on the laminated electrode group side and prevent deterioration of battery performance.

If a partition plate is used to partition the inside of the container into a plurality of cell chambers for accommodating each laminated electrode group and a lower part for a common electrolytic solution accommodating chamber for accommodating electrolytic solution, Even if the cell chambers are divided into a number of cell chambers, there is no difference in the amount of lacking electrolyte solution in each cell chamber, so the balance of the amount of electrolyte solution in each cell chamber does not change. Furthermore, since the electrolytic solution storage chamber in the lower part of the battery case is not independent for each cell chamber, it is not necessary to replenish the electrolytic solution for each cell chamber, and the replenishment operation does not become frequent.

Further, when the passage for supplying the electrolytic solution from the upper part of the battery case to the electrolytic solution storage chamber is provided in the battery case, the electrolytic solution is easily supplied to the electrolytic solution storage chamber in the lower part of the battery case. be able to.

Further, the partition plate has a structure in which a plurality of divided pieces divided at respective places of each separator are mainly used and the adjacent pieces of each divided piece are connected to each other in a state where the separator is inserted between the adjacent divided pieces. Then, the work of penetrating each separator through the partition plate can be easily performed.

Further, when the partition plate portion through which the separator penetrates is sealed with a sealant, even if the laminated nickel-hydrogen storage battery is vibrated during movement, a large amount of electrolytic solution will flow into the battery case portion where the laminated electrode group is located. Can be prevented from moving to.

[0027]

1 to 5 show a first embodiment of a laminated nickel-hydrogen battery according to the present invention.

First, a method of manufacturing the non-sintered nickel electrode 1 used in this embodiment will be described. In this example, a mixed powder was prepared by adding 10 wt% of an activator made of cobalt to nickel hydroxide powder having an average particle diameter of 15 μm, and a thickener made of 0.4 wt% sodium carboxymethyl cellulose was added to the mixed powder. Water was added to this mixed powder in a weight ratio of 0.4 and kneaded to form a slurry. Next, after pressing this slurry into a 1.0 mm thick nickel foam,
This was passed through an air stream at 80 ° C to evaporate the water content, and then compressed and compressed by a pair of rolling mills with a roll diameter of 150 mm, then 1
A piece of non-sintered nickel electrode 1 having a shape as shown in FIG. 1 was obtained by cutting into a width of 60 mm and a length of 80 mm so that the capacity per piece was 1728 mAh. A terminal 2 was connected to four sheets (6.912 Ah) of these sintered nickel electrodes 1 to obtain a nickel electrode group 3.

Next, a method of manufacturing the hydrogen electrode 4 used in this embodiment will be described. In this example, MmNiMnCo (1: 4.5: 0.2: 0.3) produced in a high-frequency melting furnace was roughly crushed by a stamp mill and then hydrogenated to 200
Finely meshed or less, mixed with 1 wt% hydroxymethyl cellulose aqueous solution to make slurry, thickness 1.0 mm
After press-fitting it into the nickel foam, it is passed through an air stream at 80 ° C to evaporate the moisture, and then a pair of rolls with a diameter of 150 mm
Pressing and compressing with a rolling mill of, then the capacity per sheet is 2350 mAh
It was cut into a width of 60 mm and a length of 80 mm to obtain a plurality of hydrogen electrodes 4 having a shape as shown in FIG. These hydrogen electrodes 4
5 terminals (11.75Ah) are connected to terminal 5 and hydrogen electrode group 6
Got

After superposing these electrode groups 3 and 6, the width
A nylon separator 7 having an average pore diameter of 20 μm cut into a size of 74 mm × length 102 mm was placed between the electrodes 1 and 4 to obtain a laminated electrode group 8.

In this laminated electrode group 8, as shown in FIG. 2 (A), an extension 7a of the separator 7 located under the electrode is A
The partition plate 9 is made to project below the BS partition plate 9.
Attached. The partition plate 9 is mainly composed of a plurality of divided pieces 9a divided for each location of each separator 7, and the respective divided pieces 9a are adjacent to each other in a state in which each separator 7 is inserted between the adjacent divided pieces 9a. The planned welding portion 9b is connected by ultrasonic welding. In this case, a sealing material 10 made of silicon rubber is attached to each divided piece 9a at a portion in contact with each separator 7, and a penetrating portion of each separator 7 of the partition plate 9 is sealed with the sealing material 10.

The laminated electrode group 8 provided with such a partition plate 9 is housed in an ABS battery case 11, as shown in FIG. The inside of the battery case 11 is partitioned by a partition plate 9 so that the upper part serves as an electrode group housing chamber 12 for housing the laminated electrode group 8 and the lower part serves as an electrolytic solution housing chamber 13 for housing an electrolytic solution.
Although not shown, the periphery of the partition plate 9 is sealed on the inner surface of the battery case 11 by ultrasonic welding or a sealing material such as an adhesive. The electrode group accommodating chamber 12 accommodates the laminated electrode group 8, and the electrolytic solution accommodating chamber 13 accommodates the electrolytic solution.

A passage 14 for supplying the electrolytic solution from the upper portion of the battery case 11 to the electrolytic solution storage chamber 13 is provided in one of the two adjacent corner portions of the battery case 11. The battery case 1
A passage 15 for venting gas from the electrolytic solution storage chamber 13 is provided in the other of the two adjacent corner portions of 1. The lower end of the passage 14 is communicated with the lower portion of the electrolytic solution storage chamber 13, and the lower end of the passage 15 is communicated with the upper portion of the electrolytic solution storage chamber 13 to facilitate degassing. It is needless to say that these passages may have only one passage 15 as long as they have a certain cross-sectional area of the passage and can simultaneously supply and degas the electrolytic solution.

An ABS battery lid 16 made of the same material as the battery case 11 is sealed at the opening of the battery case 11 by heat sealing or ultrasonic welding. The battery lid 16 has a passage 1
Liquid plugs 17, 18 for opening and closing 4, 15, and electrode group accommodating chamber 1
Safety valve 19 for venting gas from 2 and a pair of terminals 2
0 and 21 are provided.

Thus, a laminated nickel-hydrogen storage battery (product of the present invention) having a theoretical capacity of 6.9 Ah was obtained.

As a comparative example, the laminated electrode group 8 is the same as that of the present invention, and the partition plate 9 and the electrolytic solution storage chamber 13 are provided in the lower part of the battery case 11.
Electrolyte solution-rich type stacked nickel-metal hydride storage battery (Comparative Example 1) in which the electrolyte solution reaches the upper part of the battery case 11 using a battery case without a battery and a required amount of electrolysis only for the electrodes 1 and 4 and the separator 7. A liquid electrolyte-impregnated laminated nickel-hydrogen storage battery (Comparative Example 2) was prepared.

These laminated nickel-metal hydride storage batteries are
FIG. 6 shows the result of a cycle test conducted under the conditions of charging at 0 mA for 12 hours and discharging at 1.4 A to 1 V. As shown in the figure, in Comparative Example 1, the electrode active material dropped out due to excess electrolyte and short-circuited due to floating, resulting in a sharp decrease in capacity. In addition, since the electrolyte of Comparative Example 2 does not have a free electrolyte solution from the beginning, in order to stabilize the discharge capacity, a large number of electrolyte replacement solutions must be repeated as indicated by arrows in the figure. On the other hand, the product of the present invention showed stable battery performance with a small number of electrolyte replacements.

FIG. 6 shows a second embodiment of the stacked nickel-metal hydride battery according to the present invention.

The present embodiment shows an example in which the present invention is applied to a type in which the inside of the battery case 11 is partitioned by partition walls 22 to provide a cell chamber 12A as a plurality of electrode group accommodating chambers. In this embodiment, each partition plate 9 is inside the battery case 11.
In the upper part, a plurality of cell chambers 12 for accommodating each laminated electrode group 8
A and the lower part are partitioned so as to form a common electrolytic solution storage chamber 13 for storing the electrolytic solution.

The laminated electrode group 8 is accommodated in each cell chamber 12A, and the partition plate 9 attached to the lower portion thereof as described above is shared with each cell chamber 12A as described above. It is divided into 13. As in the case described above, the common electrolytic solution storage chamber 13 is configured to supply a required amount of electrolytic solution from the passage 14 while removing gas from the passage 15.

Although not shown, the battery lid is sealed at the opening of the battery case 11 as described above.

The number of cell chambers 12A is not limited to two, and the present invention can be similarly applied to any number.

In the laminated nickel-metal hydride storage battery having such a structure, the battery case 11 has several cell chambers 12A.
Even if the cell chambers 12A are separated from each other, there is no difference in the deficiency of the electrolytic solution in each cell chamber 12A, and the balance of the amount of the electrolytic solution in each cell chamber 12A does not change. Furthermore, since the electrolytic solution storage chamber 13 in the lower part of the battery case 11 is not independent for each cell chamber 12A, it is not necessary to replenish the electrolytic solution for each cell chamber 12A, and there is an advantage that the replenishment operation is not frequent.

In the laminated nickel-metal hydride storage battery according to the present invention, if all the partition plates 9 are made of ABS, the separator 7 at the contact point of each divided piece 9a is melted by ultrasonic vibration, Most of the pores of the separator 7 are lost, and the separator 7 may be broken at some places, which is not preferable. Further, when the heat welding method is used, the separator 7 is used in the same manner as above due to residual heat.
Is melted and most of the pores are lost, which is not preferable. In addition, the entire partition plate 9 is made of a rigid material such as ABS.
If such a resin is used, a space will be formed at the contact point with the separator 7, and the partition plate 9 will be vibrated due to the movement of the battery or the like.
It is not preferable because the electrolytic solution below the bottom of the lower case enters the battery case 10 in which the laminated electrode group 8 is located.

[0045]

As described above, according to the laminated nickel-metal hydride storage battery of the present invention, the following excellent effects can be obtained.

In the present invention, the inside of the battery case is partitioned by a partition plate so that the upper part is an electrode group accommodating chamber or a plurality of cell chambers for accommodating the laminated electrode group and the lower part is an electrolytic solution accommodating chamber for accommodating the electrolytic solution. Since the extension part of the separator of the laminated electrode group penetrates the partition plate and is arranged in the electrolytic solution storage chamber, the electrolytic solution in the electrolytic solution storage chamber can flow up the separator by the capillary tube and be supplied to the stacked electrode group. . Therefore, the laminated electrode group in the battery case is in a state where the electrolytic solution is regulated, and the nickel electrode active material filled in the three-dimensional mesh Ni base electrode,
Alternatively, the hydrogen electrode active material can be prevented from falling off, a minute short circuit due to floating of the drop active material can be prevented, and the battery performance can be stabilized.

Further, the electrolyte solution which becomes insufficient due to charge / discharge is
Since it is always supplied to the laminated electrode group through the separator, it is possible to prevent a shortage of the electrolytic solution on the laminated electrode group side and prevent deterioration of battery performance.

Further, by partitioning the inside of the battery case with a partition plate so that the upper part is a plurality of cell chambers for accommodating each laminated electrode group and the lower part is a common electrolytic solution accommodating chamber for accommodating an electrolytic solution,
Even if the battery case is divided into a number of cell chambers, there is no difference in the amount of lacking electrolyte solution in each cell chamber, so that the balance of the amount of electrolyte solution in each laminated electrode group can be maintained. Further, since the electrolytic solution storage chamber in the lower part of the battery case is not independent for each cell chamber, it is not necessary to replenish the electrolytic solution for each cell chamber, and there is an advantage that the replenishment operation is not frequent.

Further, by providing a passage for supplying the electrolytic solution from the upper part of the electrolytic cell to the electrolytic solution storage chamber,
The electrolytic solution can be easily supplied to the lower electrolytic solution storage chamber in the battery case.

Further, the partition plate has a structure in which a plurality of divided pieces divided at respective locations of the respective separators are mainly used, and the adjacent divided pieces are connected to each other in a state where the separators are inserted between the adjacent divided pieces. By doing so, the work of penetrating each separator through the partition plate can be easily performed.

Further, by sealing the partition plate portion through which the separator penetrates with a sealing material, even if the laminated nickel-metal hydride storage battery is vibrated during movement, the electrolytic solution will have an electrode group where the laminated electrode group is located. It is possible to prevent a large amount of movement into the storage chamber, and therefore it is possible to exert the above-mentioned effects even when the laminated nickel-hydrogen storage battery is subjected to vibration.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an example of a laminated electrode group used in a laminated nickel-hydrogen storage battery according to the present invention.

FIG. 2A is a partially cutaway perspective view showing an example of a laminated electrode group with a partition plate used in the laminated nickel-hydrogen storage battery according to the present invention, and FIG. 2B shows a laminated electrode group with a partition plate. It is a perspective view of the division piece which comprises the provided partition plate.

FIG. 3 is an exploded perspective view of a first embodiment of a stacked nickel-metal hydride storage battery according to the present invention.

FIG. 4 is a perspective view showing a state where the laminated electrode group is housed in a battery case in the first embodiment.

FIG. 5 is a perspective view showing the outer appearance of a first embodiment of a stacked nickel-hydrogen storage battery according to the present invention.

FIG. 6 is a comparative diagram showing the cycle characteristics of the product of the present invention, which is the first embodiment of the stacked nickel-hydrogen storage battery according to the present invention, and Comparative Examples 1 and 2.

FIG. 7 is a perspective view of an essential part of a second embodiment of the stacked nickel-metal hydride storage battery according to the present invention.

[Explanation of symbols] 1 non-sintered nickel electrode 2 terminal 3 nickel electrode group 4 hydrogen electrode 5 terminal 6 hydrogen electrode group 7 separator 7a extension part 8 laminated electrode group 9 partition plate 9a divided piece 9b welding part 10 sealant 11 Battery case 12 Electrode group accommodating chamber 12A Cell chamber (electrode group accommodating chamber) 13 Electrolyte solution accommodating chamber 14,15 passage 16 Battery lid 17,18 Liquid stopper 19 Safety valve 20,21 Terminal 22 Partition wall

Claims (5)

[Claims] 1. A plate-shaped non-sintered nickel electrode using nickel hydroxide powder as an active material and hydrogen storage electrochemically.
Laminated nickel-hydrogen in which flat-plate hydrogen electrodes having released hydrogen-absorbing alloy as an active material are alternately laminated via separators to form a laminated electrode group, and the laminated electrode group is housed in a battery case. In the battery, the laminated electrode group includes an extension portion of the separator that extends below a lower portion of each electrode including the non-sintered nickel electrode and the hydrogen electrode, and the inside of the battery case is a partition plate and the upper portion is the laminated. An electrode group accommodating chamber for accommodating the electrode group, the lower part is partitioned so as to be an electrolytic solution accommodating chamber for accommodating an electrolytic solution, and the extension part of the separator is disposed in the electrolytic solution accommodating chamber through the partition plate. Stacked nickel-metal hydride storage battery characterized by being 2. A plate-shaped non-sintered nickel electrode containing nickel hydroxide powder as an active material, and hydrogen storage electrochemically.
A plate-shaped hydrogen electrode whose active material is a hydrogen-absorbing alloy to be released is laminated alternately via a separator to form a laminated electrode group, and the laminated electrode group is housed in each cell chamber in a battery case. In the laminated nickel-hydrogen battery, each laminated electrode group includes an extension portion of the separator extending below a lower portion of each electrode including the non-sintered nickel electrode and the hydrogen electrode, and a partition plate inside the battery case. At the upper part is a plurality of cell chambers for accommodating each laminated electrode group, the lower part is partitioned so as to be a common electrolytic solution accommodating chamber for accommodating an electrolytic solution, and the extension part of the separator penetrates the partition plate. A stacked nickel-metal hydride storage battery, wherein the stacked nickel-hydrogen storage battery is arranged in each of the electrolytic solution storage chambers. 3. The stack according to claim 1, wherein the battery case is provided with a passage for supplying an electrolytic solution from an upper portion of the battery case to the electrolytic solution storage chamber. Type nickel-hydrogen storage battery. 4. The partition plate is mainly composed of a plurality of divided pieces that are divided at respective locations of the separator, and in a state where the separators are respectively passed between the adjacent divided pieces, the adjacent pieces of the divided pieces are separated from each other. The stacked nickel-metal hydride storage battery according to claim 1, wherein the stacked nickel-hydrogen storage battery has a connected structure. 5. The stacked nickel-metal hydride storage battery according to claim 1, wherein a portion of the partition plate that penetrates the separator is sealed with a sealing material. .