JPH11329372A - Rectangular sealed alkaline storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject battery with a high weight energy and a long service life by arranging in a resin made jar a member restraining an electrode body from being deformed without absorbing electrolyte in the battery. SOLUTION: A metal plate or high expansion type resin being a deformation restraining member of an electrode body 1 is arranged at an outside surface of the body 1 being orthogonal to the electrode stacking direction between the rectangular electrode body 1 in a polypropylene made jar 6 and an inner wall of the jar 6. This member 7 is inserted so as to surround the circumference of the body 1. A positive electrode is desirably composed of a nickel electrode. It is desirable that the thickness of the member 7 is 1-10% of the thickness of the jar 6 in the electrode stacking direction so as to suppress deformation of the electrode. Similarly, it is desirable that the total volume of the member 7 is 0.5-10% of the space volume of the jar 6 so as to suppress the deformation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed rectangular alkaline storage battery having an electrode body in which a plurality of electrodes are stacked with a separator interposed therebetween, and a resin container for housing the electrode body. The present invention relates to a battery structure of a large-sized rectangular sealed alkaline storage battery.

[0002]

2. Description of the Related Art Nickel-hydrogen storage batteries and nickel-cadmium storage batteries are used as power sources for power storage or for mobile bodies such as electric vehicles. In these applications,
In particular, batteries having a high weight energy density are demanded.
Therefore, as a battery case of these batteries, a battery case made of a resin such as polypropylene, which can achieve weight reduction and is stable against an alkaline electrolyte, is generally used.

[0003] However, it is difficult to prevent the electrode body from being deformed in the resin container, and there is a problem in current collecting performance and cycle life.

In order to solve this problem, for example,
As shown in Japanese Patent Application Laid-Open No. 7-161377, it has been proposed to restrain the outer part of the battery case with a flat metal plate. However, the effect of preventing deformation of the electrode body itself was small due to the decrease in weight energy and the restraint from the outside of the battery case due to the use of a metal as a robust metal flat plate.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a rectangular sealed alkaline storage battery having a high weight energy density and a long cycle life. To provide.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a rectangular sealed housing having an electrode body in which a plurality of electrodes are stacked via a separator, and a resin container for housing the electrode body. An alkaline storage battery, characterized in that a deformation suppressing member that suppresses deformation of an electrode body without absorbing an electrolyte solution in the battery is disposed in the resin container.

Here, the deformation suppressing member is characterized in that it is a metal plate or a highly expandable resin disposed on the outer surface of the electrode body.

Specifically, the deformation suppressing member is
It is perpendicular to the electrode stacking direction and inserted between the electrode body and the inner wall of the battery case. Alternatively, the deformation suppressing member is inserted so as to surround the periphery of the electrode body.

In the above rectangular sealed alkaline storage battery,
The effect is remarkable when a nickel electrode is used for the positive electrode. This is because when a nickel electrode is used as a positive electrode of an alkaline storage battery, γ-NiOOH is generated as the number of cycles progresses, and the positive electrode tends to expand.

[0010] The thickness of the deformation suppressing member is preferably in the range of 1% to 10% with respect to the thickness of the container in the electrode laminating direction, and the total volume of the deformation suppressing member is the space of the resin container. It should be in the range of 0.5% to 10% by volume.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments. However, the present invention is not limited to the following embodiments, and the present invention is implemented by appropriately changing the scope of the invention. Is possible. (Experiment 1) In Experiment 1, the case where a metal plate was used as a deformation suppressing member that does not absorb the electrolytic solution in the battery and suppresses deformation of the electrode body was examined.

<Example 1-1> First, hydrogen absorption as a negative electrode was performed.
Storage alloy electrode (hydrogen storage alloy composition: MmNi_Three.1Co_0.9Al _0.2M
n_0.521) and 20 non-sintered nickel electrodes as positive electrodes
Are laminated via a separator to form a substantially rectangular parallelepiped electrode body.
Was. This electrode plate is rectangular and its dimensions are positive,
Both negative electrode are 135mm in height of battery case and 87mm in width direction
It was used. Next, this electrode body was placed on an iron plate (1 mm thick).
Sandwiched between two nickel-plated 135 x 87 mm metal plates
And insert it into a resin container made of polypropylene.
Was. This metal plate does not absorb the electrolyte and changes the electrode body.
A deformation suppressing member that suppresses the shape.
And the space between the inner wall of the battery case and
You.

The outer dimensions of this resin container are 40 mm thick x width
It is 100mm x 170mm in height. The thickness of the resin container is 2m
m and 1.5 mm at the thinnest part. Thereafter, the resin container was sealed with a sealing member in which the electrode external terminals were arranged, thereby producing Battery A of the present invention. The weight of this battery A is
2038 g. The electrolyte used was a 30% by weight aqueous KOH solution.

FIG. 1 shows a schematic sectional view of the battery of the present invention.
The above-described positive electrode, negative electrode, and separator constitute a rectangular parallelepiped laminated electrode body 1. The outer surface of the electrode body 1 is substantially covered with a separator. On the upper surface of the electrode body 1, a positive electrode lead 2 connected to the positive electrode is formed. The positive electrode lead 2 and the negative electrode lead are connected to a positive external terminal 4 and a negative external terminal 5 arranged on the battery case cover 3. Although not shown, a safety valve for releasing gas to the outside of the battery case when the battery internal pressure rises abnormally is arranged on the battery case cover 3 (not shown).

The resin container 6 made of polypropylene is a box-like rectangular parallelepiped with an upper end opened, and the opening is sealed by the battery lid 3. On the inner side surface of the resin container 6 and on the outer side surface of the electrode body 1 perpendicular to the electrode laminating direction, the metal plates 7 serving as the deformation suppressing members described above are arranged.

Further, the battery case containing the electrode body 1 is fastened from the outside by fastening plates 8 and 8 and connecting pieces 9 and 9. This state is shown in FIG. FIG. 2 is a perspective view in which the battery is fastened by the fastening plate 8 and the connection piece 9. The fastening plate 8 and the connection piece 9 are formed of a 10 mm iron metal plate. Tightening plate 8 and connecting piece 9 made of this iron metal plate
Had a total weight of 2800 g. Therefore, the weight of the battery including the fastening plate and the connection piece was 4838 g.

<Example 1-2> Two 135 mm x 43 mm metal plates 10 (deformation suppressing members) obtained by applying nickel plating to an iron plate (1 mm in thickness) are parallel to the electrode laminating direction, that is, the side of the electrode body 1 Battery B of the present invention was produced in the same manner as in Example 1-1, except that the battery B was inserted between the inner walls of the battery case 6.
FIG. 3 is a schematic sectional perspective view of the battery.

The weight of the battery B is 1943 g before the fastening plate and the connection piece are attached, and 4743 g after the attachment.
It became.

<Example 1-3> Except that one strip of a 25 mm x 256 mm metal plate obtained by applying nickel plating to an iron plate (1 mm thick) was inserted so as to surround the periphery of the electrode body. A battery C of the present invention was produced in the same manner as in Example 1-1. FIG. 4 is a schematic cross-sectional view of the battery. The band-shaped metal plate 11 (deformation suppressing member) surrounds the laminated electrode body 1.

The weight of the battery C is 1952 g before the fastening plate and the connection piece are attached, and 4752 g after the attachment.
Met.

Comparative Example 1 A comparative battery X was produced in the same manner as in Example 1-1 except that a metal plate as a deformation suppressing member was not inserted into the battery case.

The weight of the battery X was 1850 g before the fastening plate and the connecting piece were attached, and 4650 g after the fastening plate and the connecting piece were attached. This battery is disclosed in
This is configured by a method similar to the technique disclosed in Japanese Patent No. 161377. (Charging / discharging test) Using each of the above batteries, a current of 12
A charge / discharge cycle test was performed in which the battery was charged for 10 hours and discharged at a current value of 10 A until the battery voltage reached 1 V.
The cycle life was determined when the discharge capacity reached 60 Ah.

Table 1 shows the discharge capacity, operating voltage (battery voltage for 1/2 hour of discharge time), weight energy density, and cycle life at 10 cycles. Further, Table 1 shows the battery weight before and after the fastening plate and the connection piece were attached from the outside of the battery, and
The calculated energy densities are displayed.
The weight A is the weight before the fastening plate and the connection piece are attached, the weight B is the weight after the fastening plate and the connection piece are attached, and the energy density A is the battery weight before the fastening plate and the connection piece are attached. Is an energy density calculated based on the battery weight after the fastening plate and the connection piece are attached.

[0024]

[Table 1]

From the results, the batteries A, B and C of the present invention were
It is understood that the comparative battery X has a higher energy density and a longer cycle life. This is considered to be due to an improvement in current collection due to an increase in the pressure of the electrode plate due to the insertion of the metal plate, and a suppression of deterioration by preventing deformation of the electrode.

In the past, only the clamping plate was used for the purpose of preventing the deformation of the electrode, but this alone is not sufficient, and the effect of the insertion of the metal plate used in the present embodiment is large. it is conceivable that.

In the above embodiment, the thickness of the metal plate inserted into the battery case is 1 mm, that is, 2.5% of the battery case thickness (40 mm in the electrode stacking direction). However, the thickness of the metal plate is preferably 1% to 10%. The reason is that if it is less than 1%, the effect of suppressing the deformation of the electrode is small, while if it exceeds 10%, the active material that can be inserted into the battery case decreases.

In the above embodiment, the total volume of the metal plate inserted into the battery case is 3.5% for the battery A, 1.7% for the battery B, and 1.7% for the battery C with respect to the space volume of the battery case. 1.0% was used, but the total volume of the metal plate was
0.5% to 10% is preferred. The reason is that if it is less than 0.5%, the effect of suppressing the deformation of the electrode is small, and if it exceeds 10%, the active material that can be inserted into the battery case decreases.

In addition, in the above-described embodiment, the metal plate is formed by plating a nickel plate on an iron plate, but a metal plate having high corrosion resistance to an aqueous alkali solution, such as a nickel plate or a stainless steel plate, may be used. (Experiment 2) In Experiment 2, the case where a highly expandable resin was used as a deformation suppressing member that does not absorb the electrolytic solution in the battery and suppresses deformation of the electrode body was examined.

<Example 2-1> The same electrode body and battery case (external dimensions: thickness 40 mm × width 100 mm × height 170 mm) as those used in Experiment 1 were prepared. Next, in place of the metal plate 7 of the deformation suppressing member used in the battery A, a flat sheet 12 of polyethylene oxide having an average molecular weight of 10,000, which is a highly expandable resin,
Two 12 pieces (135 mm × 87 mm, thickness 1 mm) were sealed and placed in a battery case. This sheet has a structure that does not absorb the electrolytic solution in the battery. This state is shown in the schematic cross-sectional view of the battery in FIG.

Further, a liquid inlet 13 is provided on the side surface of the battery case, and water is absorbed from this part to expand the sheet. This polyethylene oxide is a highly expandable resin, and is disposed on the inner surface of the battery case such that the sheet is perpendicular to the electrode stacking direction of the stacked electrode assembly. After the injection, the injection port 13 is sealed with a resin adhesive. The outer dimensions of this resin container are 40mm thick x 100mm wide x 170mm high.
mm. Thereafter, the battery case 6 was sealed with the battery lid 3 to prepare the battery D of the present invention.

In order to isolate the sheet 12 from the electrode body 1, resin films 14, 14 which are resistant to electrolytic solution and do not transmit moisture are disposed between them.

Further, in the same manner as in the battery A of the experiment 1,
The battery case 6 was fastened from outside using the fastening plates 8 and 8 and the connection pieces 9 and 9. This state is the same as FIG. 2 described above.

<Example 2-2> A polyethylene oxide sheet 13 (135 mm × 256 mm, thickness 1 mm) having an average molecular weight of 10,000, which is a highly expandable resin as a deformation suppressing member, was placed on the electrode body 1.
Example 2-1 except that it was inserted in a state surrounding the periphery of
In the same manner as in the above, a battery E of the present invention was produced. This state,
FIG. 6 is a schematic sectional view of the battery of FIG.

Comparative Example 2 A comparative battery Y was produced in the same manner as in Example 2-1 except that the deformation suppressing member was not inserted into the battery case. This battery was constructed by a method similar to the technique disclosed in JP-A-7-161377. (Charging / discharging test) Using each of the above batteries, a current
A charge / discharge cycle test was performed in which the battery was charged for 10 hours and discharged at a current value of 10 A until the battery voltage reached 1 V.
The cycle life was determined when the discharge capacity reached 60 Ah. Table 2 shows the discharge capacity, operating voltage (battery voltage for 1/2 hour of discharge time) and cycle life at 10 cycles.

[0036]

[Table 2]

From these results, it is understood that the batteries D and E of the present invention have a larger discharge capacity and a longer cycle life than the comparative battery Y. This is considered to be due to an improvement in current collecting performance due to an increase in the electrode plate pressure due to the insertion of the highly expandable resin, and to a suppression of deterioration by preventing deformation of the electrodes. It is also considered optimal to use both a high expansion resin and a fastening plate as described in Experiment 1.

In Experiment 2, the thickness of the highly expandable resin inserted into the battery case was 1 mm, that is, 2.5% of the battery case thickness (40 mm) in the electrode lamination direction. However, the thickness of the highly expandable resin is preferably 1% to 10%. The reason is that if it is less than 1%, the effect of suppressing the deformation of the electrode is small, and if it exceeds 10%, the volume of the electrode body is affected and the active material that can be inserted into the battery case is reduced.

In this embodiment, the total volume of the highly expandable resin inserted into the battery case is 3.5% for the battery D and 1.7% for the battery E, based on the volume of the battery case. The total volume of the high expansion resin can be 0.5% to 10%. The reason is that if it is less than 0.5%, the effect of suppressing the deformation of the electrode is small, while if it exceeds 10%, the active material that can be inserted into the battery case decreases.

In the above embodiment, polyethylene oxide is used as the high-expansion resin, but other than this, acrylic acid / vinyl alcohol copolymer, sodium acrylate polymer and the like can be used.

[0041]

According to the prismatic sealed alkaline storage battery of the present invention, it is possible to provide a battery having a high weight energy density and a long cycle life by suppressing the deformation of the electrode body accompanying the progress of the cycle. The value is extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a prismatic sealed alkaline storage battery according to the present invention.

FIG. 2 is a schematic sectional view of a prismatic sealed alkaline storage battery according to the present invention.

FIG. 3 is a schematic sectional perspective view of the battery of the present invention.

FIG. 4 is a schematic sectional view of the battery of the present invention.

FIG. 5 is a schematic sectional perspective view of the battery of the present invention.

FIG. 6 is a schematic sectional perspective view of the battery of the present invention.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Laminated electrode body 2 Positive electrode lead 3 Battery cover 4 Positive electrode external terminal 5 Negative external terminal 6 Resin container 7 Metal plate (deformation suppression member) 8 Tightening plate 9 Connection piece 10 Metal plate (deformation suppression member) 11 Strip-shaped metal plate (Deformation suppressing member) 12 Flat sheet (Deformation suppressing member) 13 Liquid injection port 14 Film 15 Polyethylene oxide sheet (Deformation suppressing member)

Continued on the front page (72) Inventor Ikuro Yonezu 2-5-1-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Koji Nishio 2-5-2-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (7)

[Claims] 1. A rectangular sealed alkaline storage battery comprising: an electrode body in which a plurality of electrodes are stacked via a separator; and a resin container for accommodating the electrode member, wherein a battery is provided in the resin container. A sealed rectangular alkaline storage battery characterized in that a deformation suppressing member for preventing deformation of an electrode body without absorbing an electrolytic solution therein is disposed. 2. The rectangular sealed alkaline storage battery according to claim 1, wherein the deformation suppressing member is a metal plate or a high-expansion resin disposed on the outer surface of the electrode body. 3. The rectangular sealed alkaline storage battery according to claim 1, wherein the deformation suppressing member is perpendicular to the electrode stacking direction and is inserted between the electrode body and the inner wall of the battery case. . 4. The rectangular sealed alkaline storage battery according to claim 1, wherein the deformation suppressing member is inserted so as to surround the periphery of the electrode body. 5. The prismatic sealed alkaline storage battery according to claim 1, wherein the positive electrode of the prismatic sealed alkaline storage battery is a nickel electrode. 6. The prismatic sealed alkaline storage battery according to claim 1, wherein the thickness of the deformation suppressing member is in the range of 1% to 10% with respect to the thickness of the battery case in the electrode laminating direction. . 7. The square sealed alkali according to claim 1, wherein a total volume of the deformation suppressing member is in a range of 0.5% to 10% with respect to a space volume of the resin container. Storage battery.