KR100234633B1 - Square shaped cell and method for manufacturing the same - Google Patents

Abstract

A method of manufacturing a prismatic battery according to the present invention includes the steps of accommodating an electrode assembly in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening, And the electrode group is fabricated by interposing a separator between the cathode and the anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; And a step of bonding and fixing the sealing member of the container through the insulating gasket,

Expression W _x > W _y (1)

Of the total weight of the battery.

In the above formula (1), W _x is the diametral reduction of the opening in the direction perpendicular to the longitudinal direction, W _y is the diametral reduction of the opening in the longitudinal direction, and , And W _y is 30 to 60% of the thickness of the container.

Description

A method of manufacturing a prismatic battery and a prismatic battery

FIG. 1 is a perspective view showing a container used in Examples 1 to 3 according to the present invention. FIG.

FIG. 2 is a partial sectional view showing a case where the prismatic batteries of Examples 1 to 3 according to the present invention are cut along the longitudinal direction;

FIG. 3 is a partial cross-sectional view of the prismatic battery showing the case where the prismatic cells of Examples 1 to 3 according to the present invention are cut at a plane perpendicular to the longitudinal direction.

FIG. 4 is a partial cross-sectional view showing a case where the container used in Examples 4 to 8 according to the present invention is cut at a plane orthogonal to the longitudinal direction. FIG.

FIG. 5 is a cross-sectional view showing a case where the container used in Examples 4 to 8 according to the present invention is cut along the longitudinal direction. FIG.

FIG. 6 is a top view showing a container used in Example 11 of the present invention. FIG.

FIG. 7 is a top view showing a lower die used in Examples 12 to 13 according to the present invention; FIG.

8 is a partial cross-sectional view taken along line VIII-VIII of FIG. 7;

FIG. 9 is a partial cross-sectional view taken along line IX-IX of FIG. 7; FIG.

10 is a partial cross-sectional view along line X-X of FIG. 7;

FIG. 11 is a perspective view showing a container used in Examples 12 to 13 according to the present invention. FIG.

12 is a partial cross-sectional view along line XII-XII of FIG. 11;

FIG. 13 is a partial cross-sectional view along line XIII-XIII of FIG.

FIG. 14 is a partial cross-sectional view along line XIV-XIV of FIG. 11; FIG.

FIG. 15 is a cross-sectional view for explaining a manufacturing method of a prismatic battery of Examples 12 to 13 according to the present invention. FIG.

FIG. 16 is a sectional view for explaining a manufacturing method of a prismatic battery of Examples 12 to 13 according to the present invention. FIG.

17 is a cross-sectional view for explaining a manufacturing method of a prismatic battery of Examples 12 to 13 according to the present invention.

18 is a sectional view showing a prismatic battery of Examples 12 to 13 according to the present invention.

19 is a cross-sectional view for explaining a manufacturing method of prismatic batteries of Examples 14 to 18 according to the present invention.

20 is a top view showing a curled die of FIG. 19;

21 is a partial cross-sectional view taken along line XXI-XXI of FIG. 20;

22 is a partial cross-sectional view along line XXII-XXII of FIG. 20;

23 is a cross-sectional view for explaining a manufacturing method of a prismatic battery of Examples 14 to 18 according to the present invention.

24 is a sectional view for explaining a manufacturing method of the prismatic batteries of Examples 14 to 18 according to the present invention.

25 is a sectional view showing a prismatic battery of Examples 14 to 18 according to the present invention.

Description of the Related Art

1: container 2: opening

3: end 4:

5: electrode group 6: cathode

7: separator 8: anode

9: Insulating gasket 10: Bond member

11: gas discharge hole 12: stopper plate

13: elastic valve 14: gas passage hole

15: Terminal cap 16: Lead tab

The present invention relates to a prismatic battery and a method of manufacturing a prismatic battery.

BACKGROUND ART [0002] In recent years, as a device has been reduced in size and weight, a prismatic battery having volume efficiency has been developed. As a method of sealing the prismatic battery, there is known a method of fixing the sealing member to the container by laser welding and a method of fixing the sealing member to the opening of the container by calking through the gasket.

The crimp-type prismatic battery which is pinched by the joint fixation is manufactured, for example, by the following method. That is, an opening portion of a rectangular container having a bottom is opened to form an end portion protruding inward under the opening portion. The power generation element is received in the obtained container. And the gasket in which the piercing member and the piercing member are received is placed on the end portion in the container. The opening of the container is shrunk. Next, the upper end of the opening is bent inward to compress the gasket, and the sealing member is fixed to the container by the repulsive elastic force of the gasket to manufacture the prismatic battery.

Incidentally, the side surface of the rectangular tubular container with the bottom having the opening and the end portion, which is perpendicular to the longitudinal direction, has a strength as high as that of the corner portion of the container but is difficult to bend, It is easy to deform. On the other hand, the side surface of the side surface of the container along the longitudinal direction is lower in strength than the side surface orthogonal to the longitudinal direction, and is easily bent. It is necessary to apply a greater force to the surface of the opening perpendicular to the longitudinal direction than to the other surface if the opening of the container is to be reduced in diameter with a substantially uniform width across the rolling surface. For this reason, plastic deformation occurs due to this excessive force, and the lower portion of the end portion may become too inward. In the subsequent cirque process (bending process), since the upper end of the opening is bent inward, a pressing force is applied to the container from above. When the end portion is too inwardly in the diametral reduction process, the strength of the opening portion against the pressing force is lowered. Therefore, buckling deformation occurs in the curling process, and the end portion further enters inward. As a result, since the degree of bending of the upper end of the opening becomes thinner, the degree of compression of the gasket is lowered and the seal internal pressure is lowered. When the internal pressure of the battery increases due to, for example, overcharging or improper use in a prismatic battery in which the internal pressure of the ball has been reduced, the lengthwise side of the opening is curved outward, There arises a problem that a gap is formed between the gasket and the airtightness of the battery before the safety valve is operated.

In such a diametral reduction process, the deformation of the end portion toward the inside tends to become more prominent than the portion of the end portion perpendicular to the longitudinal direction, as compared with the portion along the longitudinal direction. In addition, when the end portions are projected inward more in the shimming process and the curl process, the side surface of the body located below the end portions may be inflated outward by the recoil of the inner portion, .

An object of the present invention is to provide a method of manufacturing a prismatic battery capable of preventing deformation of a container during a diametral reduction process and a curling process (a bending process), while improving the internal pressure.

It is another object of the present invention to provide a method of manufacturing a prismatic battery in which the deformation of the container of the curling process is prevented and the packing internal pressure is improved.

It is still another object of the present invention to provide a prismatic battery having improved sealing internal pressure and a method of manufacturing the same.

A method of manufacturing a prismatic battery according to the present invention includes the steps of accommodating an electrode group in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening, The electrode group being fabricated by interposing a separator between the cathode and the anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; And a step of bonding and fixing the sealing member to the container through the insulating gasket by bending the upper end of the opening part inward after reducing the diameter of the opening part of the container,

Expression W _x > W _y (1)

Is satisfied.

In the above formula (1), W _x is the diametral reduction of the opening in the direction perpendicular to the longitudinal direction, W _y is the diametral reduction of the opening in the longitudinal direction, and , And W _y is 30 to 60% of the container thickness.

Another method of manufacturing a prismatic battery according to the present invention comprises the steps of accommodating an electrode assembly in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening, And a separator between the anode and the anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; Shrinking the sealing member of the container; And a step of bonding and fixing the sealing member to the container through the insulating gasket by bending the upper end of the opening portion inward while inserting the lower portion of the container into the rectangular hole of the lower mold,

R ₃ > R ₂ > R ₁ (2)

Is satisfied. ≪ / RTI >

In the formula (2), R ₁ represents the radius of curvature of the rising portion from the inner surface of the bottom of the rectangular hole to the inner surface of the long side, and the shin R ₂ connects from the inner surface of the bottom of the rectangular hole to the inner surface of the short- And R ₃ represents the radius of curvature of the rising portion connected to the corner from the inner surface of the bottom of the rectangular hole.

A prismatic battery according to the present invention comprises: a container having a rectangular tubular shape with a bottom and having a bent portion formed by bending an opening portion and an upper end of the opening portion downward, and an end portion protruding inwardly formed below the opening portion; An electrode group accommodated in the container and made by interposing a separator between a cathode and an anode; An electrolyte contained in the vessel; An insulating gasket disposed in a compressed state in a position wrapped by the bent portion and the end portion in the container, the insulating gasket being in the shape of a rectangular tubular with a bottom and having a hole at the bottom where the end is in contact; And a sealing member disposed in the insulating gasket, the sealing member being fixed to the container under compression of the insulating gasket, wherein the insulating gasket has an edge at the periphery of the bottom of the insulating gasket which is 10% to 60% The length of which is short.

A further method of manufacturing a prismatic battery according to the present invention comprises the steps of accommodating an electrode assembly in a bottomed rectangular tubular container having an opening and an inwardly protruding end formed below the opening, Made by interposing a separator between a cathode and an anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion in the container, the insulating gasket being in the form of a bottomed cylinder and having a hole at the bottom where the end is in contact; Shrinking the opening of the container; The upper end of the opening is folded inward by a curling die to fix the sealing member to the container, and the end portion of the sealing gasket is positioned at the periphery of the bottom surface of the insulating gasket at 10% to 60% of the thickness of the bottom portion of the insulating gasket Wherein the curled metal mold has a rectangular inverted concave portion at the bottom of the metal mold body and the inverted concave portion is formed at an intersection between the side inner surface and the upper inner surface at an upper portion of the opening and a A curled portion is formed in contact therewith,

Equation r ₁ > r ₂ (3)

Is a manufacturing method of a prismatic battery.

In the formula (3), r ₁ represents the radius of curvature of the curled portion and the radius of curvature of the corner portion, and r ₂ represents the radius of curvature of the curled portion excluding the corner portion.

A first method of manufacturing a prismatic battery according to the present invention is a method of manufacturing a prismatic battery including the steps of storing an electrode group in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening, Wherein the electrode group is fabricated by interposing a separator between the cathode and the anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; And a step of bonding and fixing the sealing member to the container through the insulating gasket by bending the upper end of the opening part inward after reducing the diameter of the opening part of the container,

The diametral width of the opening

Expression W _x > W _y (1)

Is satisfied.

In the above formula (1), W _x is the diametral reduction of the opening in the direction perpendicular to the longitudinal direction, W _y is the diametral reduction of the opening in the longitudinal direction, and , And W _y is 30 to 60% of the thickness of the container.

On the other hand, the thickness of the container means the thickness of a portion located below the end (hereinafter, referred to as a blanket).

The electrolytic solution receiving step is preferably a divided injection method in which the electrolytic solution is injected into the container by dividing the electrolytic liquid into two or more times and the final injection is performed while applying centrifugal force acting in the direction of the bottom of the container.

The final injection performed while applying centrifugal force acting in the direction of the bottom of the container means injection performed by the following method.

Wherein the container is attached to the holding means by using a device provided with a funnel supported on the rotary table so as to freely tilt and holding means for holding the container placed below the funnel, The electrolyte is contained in the funnel. When the rotary table is rotated in this state, the funnel and the holding means are moved obliquely in a direction away from the rotary table, and the posture of the funnel and the holding means is oriented almost in the horizontal direction. At this time, since the centrifugal force directed toward the bottom of the container is applied to the electrolytic solution in the funnel, the electrolytic solution is injected into the container.

Hereinafter, the above-described split injection method will be described.

It is preferable that the final injection is performed in a state where the electrolyte is infiltrated into the voids in the anode and the voids in the cathode in an amount of not less than 80% by volume. It is more preferable that the final injection is performed in a state in which the electrolyte exists in the gaps in the anode and all the gaps in the cathode.

It is preferable to perform the process of leaving the inside of the container at a reduced pressure immediately before the final injection process in order to improve the ratio of the voids in the anode and the voids in the cathode occupied by the infiltrated gaps. After such treatment, the inside of the container is returned to normal pressure and final infusion is performed in the container.

In the injection step other than the final injection step, for example, a method of performing injection while applying centrifugal force acting in the direction of the bottom of the vessel, a method of making the inside of the vessel vacuum and injecting an alkaline electrolyte into the vessel by a negative pressure A method of injecting an alkaline electrolytic solution into the container by means of a constant-volume dispensing pump can be used. Among them, a method using the centrifugal force is preferable.

From the viewpoint of improving the production efficiency of the prismatic battery by completing the electrolyte injection operation in a short time, it is preferable to inject the electrolyte solution two or three times, more preferably two times.

When the electrolytic solution is divided into two portions and injected, it is preferable that the first injection amount is set to 40 to 80% by volume of the total injection amount. More preferably, the first injection amount is in the range of 60 to 80% by volume of the total injection amount.

In the diametral reduction process, W _y is limited to the above range for the following reason. If W _y is less than 30% of the thickness of the container, the compressibility of the insulating gasket is insufficient, and the internal pressure of the seal decreases. On the other hand, if W _y exceeds 60% of the thickness of the container, it may be difficult to reduce the inward deformation of the end portion of the end portion in the direction perpendicular to the longitudinal direction. It is more preferable that W _y is 40 to 50% of the thickness of the container.

It is preferable that W _x is in a range of 35 to 75% of the container thickness.

This is due to the following reasons. If W _x is less than 35% of the container thickness, the compression ratio of the insulated gasket is insufficient. Therefore, when the long side is swollen due to an increase in the internal pressure, the seal internal pressure may decrease.

On the other hand, when W _x exceeds 75% of the container thickness, there is a fear that deformation of the container body toward the inside and deformation toward the outside due to its recoil are liable to occur. It is more preferable that W _x is in the range of 50 to 60% of the container thickness.

Further, in the diametral reduction step, W _x is greater than the widening width when the opening of the bottomed rectangular barrel is extended in a direction perpendicular to the longitudinal direction, and W _y is larger than the rectangular opening Is preferably larger than the widening width when the opening portion is extended in the longitudinal direction. When the diameter is reduced, it is possible to prevent the diameter-reduced portion from becoming larger than the body by the spring back after the completion of the curling process, so that the dimension does not match.

Next, the container, the anode, the cathode, the separator, and the electrolyte will be described.

1) container

The bottomed rectangular tubular container having the opening portion and the end portion is formed by projecting the opening portion of the bottomed rectangular barrel so as to protrude inwardly of the opening portion and thereby form an end portion. Such a container can be formed of, for example, a nickel-plated SPCC steel (cold-rolled steel of low carbon steel), nickel-plated steel, stainless steel or the like.

The width of the opening when the opening of the rectangular container with the bottom is located may be uniform over the entire circumference,

Equation Ax> Ay (2)

May be satisfied.

In the above formula (2), A _x is a widening width when the opening is extended in a direction orthogonal to the longitudinal direction, A _y is a widening width when extending the opening in the longitudinal direction, In addition, A _y is 30 to 60% of the container thickness. On the other hand, the thickness of the container means the thickness of the body of the container.

The reason for limiting the value of A _y to the above range is as follows. If _Ay is less than 30% of the vessel thickness, it may be difficult to mount the insulating gasket on the end of the vessel. On the other hand, more than 60% of the A _y the thickness of the container, the inside of the diameter step of the end portion along the longitudinal direction and the perpendicular is the concern that become difficult to reduce the variation. It is more preferable that A _y is 40 to 50% of the thickness of the drag.

It is preferable that A _x is in a range of 40 to 60% of the container thickness.

This is due to the following reasons. If the A _x is less than 40% of the container thickness, the contact area between the lower surface of the insulating gasket and the container end becomes smaller, and the seal internal pressure may decrease. On the other hand, if A _x exceeds 65% of the container thickness, the strength of the container end portion is lowered, and the opening portion in the curling process may be inclined inward from the end portion. It is more preferable that A _x is 50 to 60% of the container thickness.

The end portion may be a shape in which the stepped portion is uniform over the front crown portion,

Expression B _x > B _y (3)

May be satisfied.

In the above formula (3), B _x denotes a portion of the step in the longitudinal direction, and B _y denotes a portion of the step that is perpendicular to the longitudinal direction.

In particular, it is preferable that the end portion of the container having the opening satisfying the above formula (2) has a shape satisfying the above formula (3).

The thickness of the opening portion may be uniform over the entire peripheral edge, but may satisfy the following (4).

Expression L ₁ > L ₂ (4)

In the formula (4), L ₁ represents a surface thickness on the longitudinal direction side of the opening portion, and L ₂ represents a thickness of a surface orthogonal to the longitudinal direction of the opening portion.

In particular, it is preferable to set the thickness of the opening portion of the container having the opening satisfying the formula (2) so as to satisfy the formula (4).

Further, the thickness of the opening portion is preferably set such that when the thickness of the body of the container is L ₀ ,

Expression L ₁ ? L ₀ ? L ₂ (5)

, Or the formula L ₁ = L ₀ > L ₂ (6)

Is satisfied. The container having the structure in which the opening and the thickness of the body meet the formula (5) or the relationship expressed by the formula (6) can improve the processability of the opening while securing the battery capacity and the strength of the body It is most suitable because it can do.

Wherein the container has a thickness L _{1 of} from 1-1.1 and a thickness L _{2 of} from 0.85 to 1 when the thickness satisfies the formula (5) or the formula (6) and the thickness L ₀ is 1 It is preferable to have a structure of This is due to the following reasons.

When the thickness L ₁ is less than ₁ , the opening of the container may curve outward when a gas is generated in the cell and the internal pressure rises, so that there is a possibility that a desired sealing strength may not be obtained.

On the other hand, if the thickness L ₁ exceeds 1.1, the workability of the corners of the openings may deteriorate, so that the container may be deformed such as a distortion or a concave portion. When the thickness L ₂ is less than 0.85, the strength of the opening portion may be lowered. Therefore, in the step of bending the upper end of the opening portion, a deformation such as a concave portion or a distortion may occur on the short side of the container There is a concern. On the other hand, when the thickness L ₂ is more than 1, there is a possibility that the workability of the corners of the openings may be lowered, so that the container may be distorted or deformed such as a concave portion.

The thickness of the container is preferably 0.30 to 0.44 mm. This is due to the following reasons. If the thickness of the container is less than 0.30 mm, the retention of the bar member of the container may significantly decrease. On the other hand, as the bottom area of the container becomes larger, the thickness necessary to maintain the strength of the container tends to be thicker. When the thickness of the container exceeds 0.45 mm, the workability of the container may be lowered when the bottom area of the container is small. Further, when the bottom area of the container is large, there is a possibility that it is difficult to increase the capacity and weight of the battery. More preferably, the thickness of the container is 0.35 to 0.40 mm.

It is preferable that the Vickers hardness of the opening portion is 80Hv to 150Hv and the Vickers hardness of the body portion is 160Hv to 170Hv. By only lowering the hardness of the opening, the workability of the opening can be increased while maintaining the strength of the body.

The Vickers hardness of the opening is limited to the above range for the following reason. When the Vickers hardness is less than 80 Hv, the strength of the opening is lowered, and the opening may be deformed in the curling process. Further, since the opening is likely to expand when the gas pressure in the container rises, a gap may be formed between the opening and the insulating gasket, which may cause gas leakage. On the other hand, if the Vickers hardness exceeds 150 Hv, the workability of the opening portion is lowered, so that there is a possibility that the body of the container is deformed in the curling process. More preferably, the Vickers hardness of the opening portion is in the range of 90 Hv to 120 Hv.

On the other hand, if the Vickers hardness of the body exceeds the above range, the workability of the body may be lowered, and the strength of the body may be lowered.

2) Anode

It is preferable that the positive electrode has a structure in which the paste containing the positive electrode active material is filled in the current collector.

The anode can be produced, for example, by preparing a paste containing a positive electrode active material, a conductor, a binder and water, filling the paste into a current collector, drying the paste, and then press-molding the paste.

Examples of the positive electrode active material include nickel compounds. Examples of the nickel compound include nickel hydroxide, nickel hydroxide in which zinc and cobalt are coprecipitated, and nickel oxide. Among them, nickel hydroxide in which zinc and cobalt are coprecipitated is preferably used.

As the conductive agent, for example, one comprising one or more selected from a cobalt compound and metal cobalt can be used. Examples of the cobalt compound, for example, a cobalt hydroxide deulsu _{(C o (OH) 2)} , cobalt monoxide _(o C O) and the like.

Particularly, it is preferable to use a conductive material composed of both cobalt hydroxide, cobalt monoxide, cobalt hydroxide and cobalt monoxide.

Examples of the coupling agent include hydrophobic polymers such as polytetrafluoroethylene (PTFE), polyethylene and polypropylene such as carboxymethylcellulose (CMC), methylcellulose (MC), hydroxypropylmethylcellulose (HPMC For example, polyacrylic acid salts such as sodium polyacrylate (SPA), hydrophilic polymers such as polyvinyl alcohol (PVA) and polyethylene oxide, and rubber-based polymers such as latex.

Examples of the current collector include a metal porous body such as a net, a sponge, a fiber, or a felt formed of an alkali-resistant material such as a metal such as nickel or stainless steel or a resin plated with nickel .

3) cathode

The negative electrode preferably has a structure in which the paste containing the negative electrode active material is filled in the current collector.

Such a negative electrode can be produced, for example, by preparing a paste containing a negative electrode active material, a conductive material, a binder and water, filling the paste with a current collector, drying the paste,

As the negative electrode active material, a substance directly involved in the charge-discharge reaction or a substance capable of absorbing and releasing a substance directly involved in the charge-discharge reaction can be used. Examples of the former include, for example, powders of cadmium compounds such as metal cadmium and cadmium hydroxide. Examples of the latter include, for example, a hydrogen storage alloy for occluding and releasing hydrogen. Among them, the secondary battery having the negative electrode including the hydrogen storage alloy can discharge at a large current compared with the secondary battery having the negative electrode containing the cadmium compound powder, and there is less concern about environmental pollution , The most suitable.

The hydrogen absorbing alloy is not particularly limited as long as it is capable of absorbing hydrogen electrochemically generated in the electrolytic solution and capable of easily releasing the absorbing hydrogen at the time of discharging. For _{example, LaNi 5, MmNi 5 (Mm} ; mitsyu metal), LmNi ₅ (Lm; lanthanum enriched by mitsyu metal), or a portion thereof of the Ni Al, Mn, Co, Ti, Cu, Zn, Zr, Cr , And B, or a TiNi-based, TiFe-based, ZrNi-based, and MgNi-based ones. Among them, the formula LmNi _x Mn _y A _z (However, A is Al, at least one kind of metal selected from Co, the atomic ratio x, y, z is the total value represents the 4.8 ≤x + y + z≤5.4) Is preferably used as the hydrogen absorbing alloy. A cylindrical secondary battery having a negative electrode containing a hydrogen storage alloy having such a composition can improve discharge capacity and charge / discharge cycle life.

Examples of the conductive material include nickel powder, cobalt oxide, titanium oxide, carbon black, and the like. Particularly, it is preferable to use the carbon black as the conductive material.

As the binder, it is preferable to use the same binder as described above for the positive electrode.

Examples of the current collector include a two-dimensional substrate such as a punch metal, an expanded metal, and a nickel net; a felt-like metal porous substrate; and a three-dimensional substrate such as a sponge-type metal substrate.

4) Separator

Examples of the separator include polyolefin fiber nonwoven fabrics such as polyethylene filament nonwoven fabric, ethylene vinyl alcohol copolymer filament nonwoven fabric and polypropylene fiber nonwoven fabric to which a hydrophilic functional group is imparted, and polyamide fibers such as nylon 6,6 And a fibrous nonwoven fabric. Examples of the method for imparting a hydrophilic functional group to the polyolefin fibrous nonwoven fabric include corona discharge treatment, sulfonation treatment, graft copolymerization, and application of a surfactant and a hydrophilic resin.

5) electrolyte

Examples of the electrolytic solution include an aqueous solution of sodium hydroxide (NaOH), an aqueous solution of lithium hydroxide (LiOH), an aqueous solution of potassium hydroxide (KOH), a mixed solution of NaOH and LiOH, a mixed solution of KOH and LiOH, And an alkaline electrolyte such as a mixed solution may be used.

A second method of manufacturing a prismatic battery according to the present invention comprises the steps of accommodating an electrode group in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening, Is made by interposing a separator between a cathode and an anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; Shrinking the opening of the container; And a step of bonding and fixing the sealing member to the container through the insulating gasket by bending the upper end of the opening inward while inserting the lower portion of the container into the rectangular hole of the lower mold, Is a manufacturing method of a prismatic cell having a structure satisfying the following formula: R ₃ ? R ₂ > R ₁ (7).

In the formula (4), R ₁ represents a radius of curvature of a rising portion connected from the inner bottom surface of the rectangular hole to the inner peripheral side of the long side, and R ₂ represents the radius of curvature from the inner bottom surface of the rectangular hole to the inner surface of the short side And R ₃ represents the radius of curvature of the rising portion connected to the corner from the inner surface of the bottom of the rectangular hole.

The bottomed rectangular tubular container having the opening portion and the end portion can be obtained by, for example, dipping a metal plate such as a nickel plated SPCC steel plate (low carbon steel cold rolled steel) plate, a nickel plated steel plate or a stainless steel plate into a multi- And can be manufactured by deep-drawing processing. The container manufactured in this way often has a structure which satisfies the following expression (8) or (9) without increasing the radius of curvature of the ascending portion connected from the bottom to the side surface over the entire circumferential surface.

C ₃ ? C ₂ > C ₁ (8)

C ₃ > C ₂ = C ₁ (9)

In the above formulas (8) and (9), C ₁ denotes a radius of curvature of a rising portion connected from a bottom surface of the container to a long side, and C ₂ denotes a short side And C ₃ represents the radius of curvature of the rising portion connected to the corner from the bottom surface of the container.

The thickness of the container is preferably set to 0.30 to 0.45 mm for the reason described in the above-described first prismatic battery manufacturing method.

It is preferable that the Vickers hardness of the opening portion is set to 80 Hv to 150 Hv and the Vickers hardness of the body portion is set to 160 to 170 Hv for the reason described in the above-described manufacturing method of the first prismatic battery.

The lower mold can be formed of, for example, a hard metal such as a tungsten carbide alloy.

The lower mold is characterized in that the rectangular hole satisfies the formula (7); Satisfying R ₃ ≥ R _2> R ₁ and also for the, R _2, said R ₃ is the C _2, the same as the C _3, respectively, or, or substantially the same, and, furthermore, the R ₁ is the C ₁ It is preferable to have a smaller structure.

The lower mold is characterized in that the curvature radius R ₃ of the rectangular hole is 200% to 300% of the container thickness, the curvature radius R ₂ is 100% to 220% of the container thickness, It is preferable that the curvature radius R ₁ of the portion located at the center portion of the rising portion leading to the inner peripheral surface is 0% to 170% of the container thickness. This is due to the following reasons.

When the radius of curvature R3 is less than 200% of the container thickness, the corner portion and the lower portion of the container bottom portion having the greatest strength become unlikely to sputter, and the corner portion deforms greatly, . On the other hand, when the radius of curvature R ₃ exceeds 330% of the container thickness, only the corner portion of the bottom of the container comes into contact with the lower mold, and the corner portion may be significantly deformed. A more preferable radius of curvature R ₃ ranges from 250% to 300% of the container thickness.

When the curvature radius R ₂ is less than 100% of the container thickness, the side of the short side of the bottom of the container having a large strength is not in contact with the bottom, and if it can not be supported at the corner of the bottom of the container, Buckling deformation may occur.

On the other hand, when the radius of curvature R ₂ exceeds 220% of the container thickness, only the short side of the bottom of the container is in contact with the bottom, so that the short side may be significantly deformed. A more preferable radius of curvature R ₂ is in the range of 150% to 200% of the container thickness.

When the radius of curvature R ₁ exceeds 170% of the container thickness, there is a fear that a portion having the curvature radius R ₁ of the lower half of the container bottom portion and the central portion of the container bottom portion abut on each other and deform the body of the container. When the radius of curvature R ₁ is 0% of the container thickness, the lower mold has a structure in which the inner surface of the bottom of the rectangular hole and the central portion of the inner surface on the side of the long side of the rectangular hole are perpendicular to each other. A more preferable radius of curvature R ₁ is in the range of 120% to 150% of the container thickness.

As the positive electrode, the negative electrode, the separator and the electrolytic solution, those described in the above-described first method for producing a prismatic battery can be used.

The electrolytic solution receiving step can be carried out by the same method as described in the above-described first prismatic battery manufacturing method.

A prismatic battery according to the present invention comprises: a container having a rectangular tubular shape with a bottom having a bent portion formed by bending an opening portion and an upper end of the opening portion inwardly and an end portion protruding inwardly formed below the opening portion; An electrode group housed in the container and made by interposing a separator between a cathode and an anode; An electrolytic solution contained in the vessel; An insulated gasket disposed in a compressed state in a position wrapped by the bent portion and the end portion in the container; the insulated gasket being in the shape of a rectangular tubular with a bottom, and having a hole at the bottom where the end abuts; And a sealing member which is disposed in the insulating gasket and which is fixedly joined to the container under the compression of the insulating gasket, wherein the insulating gasket is formed so that the end of the insulating gasket is located at the periphery of the bottom of the insulating gasket at 10% to 60% It is a prismatic cell with a length equivalent to a minute.

The insulating gasket may be formed of, for example, polypropylene, polysulfone, nylon 6,6 or the like. It is preferable that the nylon 6,6 be subjected to moisture absorption treatment.

It is preferable that the moisture absorption treatment is carried out by leaving the insulating gasket made of nylon 6,6 in the air having a temperature of 25 ° C to 65 ° C and a humidity of 80% to 93% for 0.5 to 60 hours. Since the insulating gasket made of nylon 6,6 subjected to hygroscopic treatment under such conditions is excellent in flexibility, the adhesion between the rising portion and the inner surface of the container end portion at the bottom edge can be improved, which is preferable.

It is preferable that the insulating gasket has a structure in which the thickness of the bottom portion is 0.2 to 0.5 mm and the thickness of the rising portion is 0.4 to 0.6 mm.

The end of the container is pierced by the above-mentioned length at the bottom periphery of the insulating gasket for the following reason. When the internal pressure of the battery is increased, the inner surface of the end portion of the container tends to deviate from the raised portion of the bottom of the insulating gasket when the inner dimension of the bottom of the insulating gasket is less than 10% of the bottom thickness of the insulating gasket. do. On the other hand, if the punched dimension exceeds 60% of the bottom thickness of the insulating gasket, the container deforms during the bending process. A more desirable patch dimension is a length corresponding to 15% to 50% of the bottom thickness of the insulating gasket.

The container may be formed of, for example, nickel-plated SPCC steel (mild steel of low carbon steel), nickel-plated steel, stainless steel or the like.

The thickness of the container is preferably 0.30 to 0.45 mm for the same reason as described in the above-described first prismatic battery manufacturing method.

It is preferable that the Vickers hardness of the opening portion is set to 80 Hv to 150 Hv and the Vickers hardness of the body portion is set to 160 to 170 Hv for the reason described above in the manufacturing method of the first prismatic battery.

As the negative electrode, the positive electrode, the separator, and the electrolytic solution, those same as those described in the above-described first method for producing a prismatic battery can be used.

The prismatic battery can be manufactured, for example, by the following method.

The method for manufacturing a prismatic battery includes the steps of accommodating an electrode group in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening, Made by interposing a separator; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; The insulating gasket has a bottomed rectangular tubular shape and has a hole at the bottom where the end is in contact; Shrinking the opening of the container; The upper end of the opening is folded inward by a curling die to fix the sealing member to the container, and the end portion of the sealing gasket is positioned at the periphery of the bottom surface of the insulating gasket at 10% to 60% of the thickness of the bottom portion of the insulating gasket Wherein the curled metal mold has a rectangular inverted concave portion at the bottom of the metal mold body and the inverted concave portion is formed at an intersection between the side inner surface and the upper inner surface at an upper portion of the opening and a A curled portion is formed in contact therewith,

Equation r ₁ > r ₂ (5)

Is a manufacturing method of a prismatic battery.

It is preferable that the radius of curvature r ₁ be 1.1 to 1.4 when the radius of curvature r ₂ is 1. This is for the following reasons. If the radius of curvature r1 is less than 1.1, it may be difficult to set the depth of the insulating gasket to the above range. On the other hand, if the radius of curvature r ₁ exceeds 1.4, the folded state of the upper end of the opening portion of the container becomes too deep, so that the punched dimension may exceed 60% of the thickness of the bottom portion of the insulating gasket.

In addition, there is a fear that the insulated gasket is pressed too far and dropped at the end of the container. Further, excessive pressure is applied to the trunk or the bottom of the container, and there is a fear that deformation such as laceration or distortion may occur. The size of the more preferable radius of curvature r ₁ is 1.15 to 1.35.

It is preferable that the inverted concave portion is formed with a batten taper having an angle of 0.5 DEG to 10 DEG with respect to the inner peripheral surface of the lower end thereof. The curled metal mold having the taper can smoothly remove the container after the curling process.

The mold may be formed of a cemented carbide such as a carbonitungsten alloy. The electrolytic solution receiving step may employ the same method as that of the first prismatic battery manufacturing method described above.

As described above, the first method of manufacturing a prismatic battery according to the present invention is a method of manufacturing a prismatic battery according to the present invention, in which an electrode group is housed in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening In the process, the container is fabricated by opening an opening of a bottomed rectangular container, the electrode group being fabricated by interposing a separator between the cathode and the anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; And a step of bonding and fixing the sealing member to the container through the insulating gasket by bending the upper end of the opening part inward after reducing the diameter of the opening part of the container,

Expression W _x > W _y (1)

Is satisfied. ≪ / RTI >

By setting the diametral axis width in this manner, it is possible to avoid an excessive force from being applied to the surface orthogonal to the longitudinal direction of the opening portion in the diametral reduction process, so that the deformation of the end portion formed below this surface can be suppressed have. Therefore, in the curling process, since the end portion can be prevented from entering the inside due to the buckling deformation, the upper end of the opening can be bent deeply inward. Therefore, it is possible to manufacture a prismatic battery in which the dimensions are not matched and the packing internal pressure is improved.

In the above manufacturing method, by setting the widening width of the opening portion of the container to satisfy the expression (2) A _x > A _y , it is possible to prevent the portion of the end portion, which is perpendicular to the longitudinal direction, It is possible to bend the upper end of the opening deeply inward without causing buckling deformation in a plane orthogonal to the longitudinal direction of the opening in the curling process. Further, since the container can sufficiently increase the step of the end portion in the longitudinal direction, the insulating gasket can be stably held at the end portion. Therefore, by using the container, it is possible to greatly reduce the amount of deformation of the end of the diametral reduction process and the curling process, and at the same time, the retaining property of the insulating gasket of the container can be improved. Therefore, the container dimensions are not matched, Thereby producing a prismatic battery.

Further, in the container having the opening reached to satisfy the above-mentioned formula (2), the end portion of the container has a shape satisfying the formula (3) B _{x &} gt _; And deformation of the end portion in the diametral reduction step of the portion perpendicular to the longitudinal direction can be greatly reduced, so that the seal internal pressure can be remarkably improved.

In the container having the opening reached to satisfy the formula (2), it is preferable that the opening has a thickness satisfying the formula (4); By making the structure satisfying L ₁ > L ₂ , the workability of the opening can be improved. Therefore, deformation of the end of the diametral reduction step and the curling step toward the inside can be greatly suppressed, It can bend. At the same time, the strength of the surface of the opening in the longitudinal direction can be improved. Therefore, when the internal pressure of the cell increases due to, for example, overcharging or improper use, It is possible to restrain the surface from curving outward. Therefore, since the deformation of the end portion of the piercing process can be suppressed and the surface strength of the opening portion in the longitudinal direction can be simultaneously achieved, the seal internal pressure can be remarkably improved.

Further, in the above manufacturing method, the electrolytic solution receiving step is performed by dividing and injecting the electrolytic solution into the container at least two times, while the final injection is performed while applying centrifugal force acting in the direction of the bottom of the container, In order to increase the capacity of the prismatic battery, even when the electrode group is housed in the container in a solid state or a paste-type electrode is employed, a predetermined amount of electrolyte can be infiltrated into the electrode group in the container in a precise and short time . There is a possibility that the inner surface of the container opening is contaminated by the electrolyte when the electrolyte does not penetrate into the electrode group in the container at the time of injection but stays on the upper portion of the electrode group. Further, in the case where a sealant (for example, made of an asphalt-based material) is applied to the inner surface of the opening, the sealant may be deteriorated. If the inner surface of the opening is fouled or the sealant aggravates, the adhesion between the container and the insulating gasket is lowered, and the airtightness is lowered, resulting in poor sealing. Therefore, when the above-described electrolytic solution receiving step is performed by the split injection method, it is possible to manufacture a prismatic battery having a high internal resistance and high reliability and a high capacity at a high yield.

In addition, the inside of the vessel is depressurized immediately before the final injection process to allow the electrolyte solution to permeate a predetermined amount of the electrolytic solution with high precision and in a shorter time by the electrode group.

A second method of manufacturing a prismatic battery according to the present invention comprises the steps of accommodating an electrode group in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening, Is made by interposing a separator between a cathode and an anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; Shrinking the opening of the container; And joining and fixing the sealing member to the container through the insulating gasket by bending the upper end of the opening inward while inserting the lower portion of the container into the rectangular hole of the lower mold,

R ₃ > R ₂ > R ₁ (7)

Is a manufacturing method of a prismatic battery.

According to such a method, since the deformation of the container in the curling process can be suppressed or prevented, it is possible to provide a prismatic battery having an improved sealing internal pressure.

As described above, the container tends to have the structure satisfying the formula (8) or the formula (9). In the container satisfying the formula (8) or the formula (9), the radius of curvature of the portion located at the center of the rising portion among the radius of curvature C ₁ tends to be the smallest.

For this reason, conventionally, as the lower mold, a rectangular hole has the same shape as the radius of curvature of the rising portion leading from the inner surface of the bottom portion to the inner surface of the bottom portion and the radius of curvature of the portion located at the central portion of the rising portion leading from the bottom surface to the long- I am using it. When a lower portion of the container is inserted into a rectangular hole having such a shape, a rising portion extending from the bottom surface of the container to a long side side surface is fitted to a rising portion extending from the bottom inner surface of the rectangular hole to the long side side inner peripheral surface, The container is fixed to the lower mold. Subsequently, when the curling process is performed, a pressure is applied to the container. When a pressure is applied to the container, the container deforms so that the radius of curvature of the rising portion from the bottom surface to the side surface of the side surface is kept small so as to balance with the pressing force. However, since there is no extra space in the portion of the container which is fitted with the lower mold, a deformation in which the radius of curvature becomes small can not be performed, and a load is applied to this portion of the container. Further, the strength of the container against the pressing force is lowered in the order of the corner, the side of the short side, and the side of the long side. Therefore, if such a load is applied to the rising portion that extends from the bottom surface of the container to the side surface on the side of the long side, buckling deformation may occur in the container, and a concave portion may be formed on the lower side surface of the long side of the container. When such a deformation occurs in the container in the curling process, it becomes difficult to bend the upper end of the opening portion of the container into a desired shape, resulting in a decrease in the seal inner pressure.

When the lower portion of the container is inserted into the rectangular hole of the lower mold according to the manufacturing method of the present invention, the container has a line portion extending from the bottom surface to the side of the short side side from the bottom inner surface of the rectangular hole to the rising portion And a rising portion extending from the bottom face to the long side side face is fixed to the bottom face with a desired distance from the rising portion leading from the bottom inner face of the rectangular hole to the long side side inner peripheral face. When the upper end of the opening portion of the container is bent in this state, a pressing force is applied to the container, and a load is applied to a rising portion extending from the bottom surface to the side of the short side of the container. However, , The container can be supported.

In addition, buckling deformation can be prevented from occurring in the container because there is a clearance between a portion extending from the bottom surface of the container to the long side and a rising portion extending from the bottom inner surface to the long side side inner peripheral surface of the rectangular hole. As a result, the upper end of the opening of the container can be bent at a desired angle to attach the sealing member to the sealing member with high airtightness, so that the sealing pressure and reliability of the battery can be improved.

Further, in the manufacturing method, the electrolytic solution receiving step is performed by dividing and injecting the electrolytic solution into the container at least two times, and by performing the final injection while applying a centrifugal force acting in the direction of the bottom of the container, Even when the electrode group is housed in the container in a solid state or a paste-type electrode is employed, a predetermined amount of electrolyte can be precisely and quickly penetrated into the electrode group in the container. Therefore, it is possible to manufacture a prismatic battery having a high internal pressure and high reliability and a high capacity at a high yield.

In addition, immediately before the final injection step, the inside of the vessel is depressurized and left standing, so that a predetermined amount of electrolytic solution can be infiltrated by the electrode group with high precision and in a short time.

A prismatic battery according to the present invention comprises: a container having a rectangular tubular shape having an opening, a bent portion formed by bending the upper end of the opening inwardly, and a bottom portion protruding inwardly formed below the opening; An electrode group housed in the container and made by interposing a separator between the anode and the cathode; An electrolyte contained in the vessel; An insulated gasket disposed in a compressed state at a position wrapped by the bent portion and the end portion in the container, the insulated gasket being in the shape of a rectangular tubular with a bottom and having a hole at the bottom where the end abuts; And a sealing member which is disposed in the insulating gasket and which is fixed to the container under the compression of the insulating gasket, wherein the insulating gasket is formed such that the end of the insulating gasket has a thickness of 10% to 60% It is a prismatic cell with a length equivalent to the length.

According to such a battery, a gas is generated in the battery to increase the internal pressure of the battery, and when the center portion of the opening in the longitudinal direction is curved outward due to the gas pressure, It is possible to prevent falling off from the raised portion, and to avoid deterioration of the airtightness. Therefore, since the seal internal pressure can be improved, the reliability can be improved.

Further, when the insulating gasket is formed of the absorbed nylon 6,6, such an insulating gasket can improve the flexibility of the insulating gasket, so that the adhesion with the container can be improved, and the sealing internal pressure of the prismatic battery can be remarkably increased Can be improved.

A method of manufacturing a prismatic battery according to the present invention comprises the steps of accommodating an electrode group in a container having a bottom and a rectangular tubular shape having an opening and an end projecting inwardly formed below the opening, Made by interposing a separator in an anode phase; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; The insulating gasket has a bottomed rectangular tubular shape and has a hole at the bottom where the end is in contact; Shrinking the opening of the container; Wherein the upper end of the opening is folded inward by a metal mold to fix the sealing member to the container, and the end portion of the sealing gasket is fixed to the bottom periphery of the insulating gasket by a length corresponding to 10% to 60% Wherein the curled metal mold has a rectangular inverted concave portion at the bottom of the metal mold body and the inverted concave portion is curled at the intersection of the inner side surface of the mold and the inner surface of the upper portion, Further,

Equation r ₁ > r ₂ (5)

Is a manufacturing method of a prismatic battery.

According to this method, in the curling process, first, the corner of the upper portion of the opening portion is brought into contact with the portion of the curled portion and the corner portion of the inverted concave portion. Therefore, the corner at the upper end of the opening can be folded inward without causing the thickness to accumulate in the edge portion.

Thereafter, a portion of the curled portion of the inverted concave portion except for the corner portion is brought into contact with the edge portion of the upper end of the opening portion. Therefore, since the upper end of the opening can be bent in a state where the corner at the upper end of the opening is bent inward in advance, it is possible to suppress the accumulation of the thickness at the corner when the side is bent. Therefore, the upper end of the opening can be folded into a desired shape, and the end portion of the container can be punched out to the peripheral edge of the bottom of the insulating gasket by the above-mentioned characteristic dimensions, and the above- have.

According to the above method, since excessive pressure is not applied to the container during the curling process, it is possible to prevent deformation such as a concave portion or distortion in the body or the bottom of the container.

Further, in the above manufacturing method, the electrolytic solution receiving step is performed by dividing and injecting the electrolytic solution into the container at least two times, and the final injection is performed while applying a centrifugal force acting in the direction of the bottom of the container, Even when the group is housed in a container in a solid state or a paste-type electrode is employed, a predetermined amount of the electrolyte can be precisely and quickly penetrated into the electrode group in the container. Therefore, it is possible to manufacture a prismatic battery having a high internal pressure and high reliability and a high capacity at a high yield.

In addition, immediately before the final injection step, a predetermined amount of the electrolytic solution can be infiltrated by the electrode group with high precision and in a short period of time by performing a process of depressurizing the inside of the container and leaving the inside thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Example 1]

First, a nickel substrate having a three-dimensional network structure was pressed so that its end was formed with a current collecting terminal attachment portion. 10 parts by weight of cobalt monoxide as a conductive agent was added to 90 parts by weight of nickel hydroxide powder, and 0.175% by weight of sodium polyacrylate and 30% by weight of water as a binder were added to this mixture and kneaded to prepare a paste. The paste was filled on the nickel substrate except for the current collector terminal attachment portion, and then dried, rolled, and lead tabs were welded. This was cut into a size of 39.2 x 14.7 mm by a punching press to produce a positive electrode.

On the other hand, 0.5 part by weight of a polyacrylate as a binder, 1 part by weight of carbon as a conductive powder and 50 parts by weight of water were kneaded to 100 parts by weight of a hydrogen storage alloy powder having a composition of LmNi _4.0 Co _0.4 Mn _0.3 Al _0.3 to prepare a paste, This paste was coated with punch metal, dried and rolled, and then cut into a size of 39.2 mm × 15.2 mm by a dedicated press to produce a negative electrode.

Subsequently, the positive electrode was sandwiched by a bag-shaped separator made of a polyolefin fibrous nonwoven fabric imparted with hydrophilic functional groups, and three sheets of the laminate and four negative electrodes were prepared, and these were stacked on each other to prepare an electrode group.

From the nickel plated SPCC steel, a bottomed rectangular barrel having a width of 16.4 mm along the longitudinal direction, a width of 5.6 mm perpendicular to the longitudinal direction, and a thickness of 0.4 mm was made by drawing. The opening of the opening was extended so as to have a widening width of 0.22 mm, and an end portion protruding inward was formed below the opening to prepare a container. 1, the container 1 comprises an opening 2 and a bottomed rectangular container 4 having an end 3 formed in the lower portion of the opening 2 and projecting inwardly, Shape. In addition, the end portion has a structure in which all steps are 0.20 mm. Further, the Vickers hardness of the opening portion is 100 Hv and the body Vickers hardness is 160 Hv. On the other hand, the container also serves as a negative terminal.

On the other hand, the elastic valve manufactured by compression molding synthetic rubber was inserted into the top of a cap-shaped terminal cap having a plurality of gas passage holes. Next, the terminal is mounted on a rectangular punching plate having a gas vent hole so that the elastic valve closes the gas vent, and the flange portion of the terminal is fixed to the sealing plate by spot welding to form an explosion- And a pincushion member serving also as a terminal was assembled.

After the electrode group was housed in the container, an asphalt-based sealing agent was applied to the inner peripheral surface of the opening of the container. 40% by volume of 1.1 ml of an alkaline electrolyte consisting of 7N of potassium hydroxide and 1N of lithium hydroxide was injected into the vessel for 20 seconds while applying centrifugal force acting in the direction of the bottom of the vessel. After the container was left for 3 minutes, the inside of the container was reduced to 500 mmHg and allowed to stand, and then the inside of the container was returned to normal pressure. Subsequently, the remaining electrolyte was injected into the vessel for 20 seconds while applying centrifugal force acting in the direction of the bottom of the vessel. The degree of penetration of the electrolytic solution into the electrode group at this time was observed, and the total amount of the electrolytic solution was permeated into the electrode group.

Then, after the peg member (formed of nylon 6,6) is housed in an insulating gasket having a bottomed rectangular tubular shape and having a hole at the bottom, the bottom surface of the peg plate of the peg member, The tip was welded. Then, the insulating gasket was placed on the end of the container.

The opening of the container

Expression W _x > W _y (1)

Respectively.

That is, when the diametral width W _y when the opening is reduced in the longitudinal direction is 0.24 mm, that is, the thickness of the body of the container is 60%, and the diameters of the diameters of the diameters of the openings in the direction perpendicular to the longitudinal direction W _x was 0.25 mm (62.5% of the body thickness of the container). Next, in the curling process, the upper end of the opening is bent inward, and the sealing plate is fixed to the container through the insulating gasket, and has the structure shown in FIGS. 2 and 3, The number of cathodes, anodes and separators used in the electrode group shown in the second and third figures to be described later is different from that of the electrode group manufactured by the above-described method), and a rectangular nickel electrode having a size of 16.4 x 5.6 x 48.0 (mm) Thereby preparing a hydrogen secondary battery.

2 and 3, the container 1 having the opening portion 2 and the end portion 3 is formed in such a manner that the upper end of the opening portion 2 is bent inward, Respectively. In the container 1, the electrode group 5 is accommodated. The electrode group 5 is formed by alternately stacking five cathodes 6 and four positive electrodes 8 wrapped with the coarse separator 7 and alternately stacking them. The electrode group 5 is accommodated in the container 1 so that the inner circumferential surface of the container 1 and the cathode 6 are in contact with each other. The electrolyte solution is permeated into the electrode group (5) in the container (1). The insulating gasket 9 has a rectangular tubular shape with a bottom, and a rectangular hole 9a is opened at the bottom. The insulating gasket 9 is disposed in a compressed state in a position wrapped by the bent portion 4 and the end portion 3 in the container 1. The sealing member 10 is disposed in the insulating gasket 9 and fixed to the container by the repulsive elastic force of the insulating gasket 9. The sealing member 10 includes the sealing plate 12 having the gas cylinder and the hole 14, the elastic valve 13, the terminal cap 15 having the plurality of gas cylinders and the hole 14, . The elastic valve (13) is placed on the seal plate (12) so as to cover the gas discharge hole (11). The terminal cap 15 is arranged to surround the elastic valve and fixed to the sealing plate 12 by welding. The other end of the lead tab 16 connected to the positive electrode 8 at one end is connected to the lower surface of the sealing plate 12.

[Example 2]

In the same manner as in Example 1 except that W _x was 0.25 mm (62.5% of the body thickness of the container), and W _y was 0.18 mm (45% of the body thickness of the container) A battery cell was manufactured.

[Example 3]

The same procedure as in Example 1 was conducted except that W _x was 0.25 mm (62.5% of the body thickness of the container), and W _y was 0.12 mm (30% of the body thickness of the container) A battery cell was manufactured.

[Comparative Example 1]

A rectangular nickel-hydrogen secondary battery was produced in the same manner as in Example 1 except that W _x and W _y were both 0.25 mm.

[Comparative Example 2]

In the same manner as in Example 1 except that W _x was 0.25 mm (62.5% of the body thickness of the container), and W _y was 0.10 mm (25% of the body thickness of the container) A battery cell was manufactured.

[Comparative Example 3]

In the same manner as in Example 1 except that W _x was 0.25 mm (62.5% of the body thickness of the container), and W _y was 0.30 mm (75% of the body thickness of the container) A battery cell was manufactured.

The external appearance of the obtained secondary batteries of Examples 1 to 3 and Comparative Examples 1 to 3 was observed, and the presence or absence of deformation of the diametral reduction step and the curling step was examined. The results are shown in Table 1 below.

In addition, holes were provided on the lower side surfaces of the containers of the secondary batteries of Examples 1 to 3 and Comparative Examples 1 to 3, and the gas was sent from the holes to the container. The openings curved outward, The pressure in the container was measured when a gap was formed between the gasket and the gas leaked from the gap. The pressure in the container was measured, and the results are shown in Table 1 below.

As is evident from Table 1, the diameters of the diameters of the openings of the container

Expression WW (1)

The batteries of Examples 1 to 3 having diametrically opposed diameters satisfying the above-described diameters do not match with each other, and it can be seen that the packing internal pressure is higher than those of Comparative Examples 1 to 3. In addition, the batteries of Comparative Examples 1 and 3 caused buckling deformation in a plane orthogonal to the longitudinal direction of the openings in the curling process.

[Example 4]

A rectangular nickel-hydrogen secondary battery was produced in the same manner as in Example 1 except that the container shown below was used.

As described above, a rectangular tubular opening having the same bottom is formed in the above-

Equation AA (2)

And an end portion of the projecting shape inward was formed below the opening portion to produce a container shown in FIG. 4 and FIG. 5. FIG. 4 and 5, the container 17 includes an opening 18 and an end portion 19 formed in the lower portion of the opening 18 and protruding inwardly. The branch has a rectangular tubular shape with a bottom. The widening width A of the opening 18 along the longitudinal direction is 0.25 mm (62.5% of the body thickness of the container 17), and of the opening 18, A is 0.1 mm, which corresponds to 25% of the thickness of the body of the container 17. In addition, the end portion 19 has a structure in which the steps B and B are all 0.20 mm. Further, the Vickers hardness of the opening portion is 100 Hv and the hardness of the body Vickers is 160 Hv. The container also serves as a negative terminal.

[Example 5]

The same procedure as in Example 4 was carried out except that the A was changed to 0.25 mm (62.5% of the body thickness of the container) and the A was changed to 0.12 mm (30% of the body thickness of the container) .

[Example 6]

The same procedure as in Example 4 was carried out except that A was changed to 0.25 mm (62.5% of the body thickness of the container), and A was changed to 0.18 mm (45% of the body thickness of the container) .

[Example 7]

The same procedure as in Example 4 was carried out except that A was changed to 0.25 mm (62.5% of the body thickness of the container) and A was changed to 0.22 mm (55% of the body thickness of the container) .

[Example 8]

A rectangular Ni-MH secondary battery (manufactured by Tosoh Corporation) was produced in the same manner as in Example 4 except that A was changed to 0.25 mm (62.5% of the body thickness of the container) and A was changed to 0.24 mm .

[Example 9]

A rectangular Ni-MH secondary battery was produced in the same manner as in Example 4 except that both A and A were 0.25 mm (62.5% of the body thickness of the container).

For the obtained secondary batteries of Examples 4 to 9, the outer appearance of the container was observed, and the presence or absence of deformation of the diametral reduction process and the curling process was examined. The results are shown in Table 2 below.

Further, for the secondary batteries of Examples 4 to 9, the endurance pressure was determined in the same manner as described above, and the results are summarized in Table 2 below.

As is evident from Table 2, the batteries of the Examples are not inconsistent with the dimensions and shape of the container, and the fact that the internal pressure of the bag is high can be seen. Among them,

Equation AA (2)

It can be seen that the batteries of Examples 5 to 8 using the container having the opening having the structure satisfying the requirements of the present invention have a significantly high internal pressure.

[Example 10]

The widening width A is 0.28 mm (55% of the body thickness of the container), the widening width A is 0.18 mm (45% of the body thickness of the container), B (step along the longitudinal direction of the container) And a B (a step orthogonal to the longitudinal direction of the container) of 0.18 mm was prepared in the same manner as in Example 1. The results are shown in Table 1.

With respect to the obtained secondary battery of Example 10, the outer appearance of the container was observed, and the presence or absence of deformation of the diametral reduction step and the curling step was examined, and no deformation was observed.

Further, for the secondary battery of Example 10, the internal pressure of the bag was determined by the above-described method, and it was 13 to 16 kg / cm Respectively.

[Example 11]

A rectangular nickel-hydrogen secondary battery was produced in the same manner as in Example 1 except that the container shown in FIG. 6 was used.

As shown in FIG. 6, the container 20 includes an opening 21 and a bottomed rectangle (not shown) having an inwardly projecting end (not shown) formed below the opening 21 Thereby forming a cylindrical shape. The surface thickness L of the opening 21 in the longitudinal direction is 0.42 mm and the thickness L of the surface orthogonal to the longitudinal direction of the opening 21 is 0.38 mm. The body thickness L of the container 20 is 0.4 mm. The widening width A of the opening 21 along the longitudinal direction is 0.22 mm (55% of the body thickness of the container 20), and the widening width A of the surface of the opening 21, A is 0.18 mm, which corresponds to 45% of the body thickness of the container 20. Further, the end portion has a structure in which the steps B and B are all 0.2 mm. The opening 21 has a structure in which the width of the opening satisfies the formula (2) AA and the thickness satisfies the expression (4) LL.

With respect to the obtained secondary battery of Example 11, the outer appearance of the container was observed, and the presence of deformation of the diametral reduction step and the curling step was examined, and no deformation was observed.

Further, for the secondary battery of Example 11, the internal pressure of the bag was obtained by the method as described above, and it was 12 to 15 kg / cm Respectively.

[Example 12]

First, the lower mold used in the twelfth embodiment will be described with reference to FIGS. 7 to 10. FIG.

7, the lower mold comprises a lower mold body 30 having a partially cutaway cylindrical shape, a rectangular hole 31 opened in the main body 30, and a lower portion 31 of the rectangular hole 31 And a knockout (32) moving up and down the hollow portion and the rectangular hole (31). The lower mold having such a structure is formed of a tungsten carbide alloy. The lower mold is as shown in Fig. The radius of curvature R of the rising portion extending from the inner surface of the bottom portion to the inner surface of the long side portion is 0.4 mm (100% of the thickness of the container body), and as shown in FIG. 9, (200% of the container body thickness). As shown in FIG. 10, the radius of curvature R of the rising portion leading from the inner surface of the bottom portion to the corner is 0.8 mm (200% of the container body thickness). That is, the lower mold has a structure satisfying the formula R? RR (7).

Next, the manufacturing method of the prismatic battery will be described in detail.

First, a bottomed barrel is formed by drawing in a steel plate, and then an opening portion of the bottomed barrel is expanded to form an end portion protruding inwardly below the opening portion. The container shown in Fig. 11 Respectively. As shown in FIG. 11, the container 33 has a bottomed rectangular barrel shape having the opening portion 34 and the end portion 35. The container 33 has a plate thickness of 0.4 mm, a width on the longitudinal side of 16.4 mm, and a width on the side perpendicular to the longitudinal direction of 5.6 mm. As shown in Fig. 12, the container 33 has a radius of curvature C of 0.7 mm, which is a rising portion extending from the bottom surface to the central portion of the side surface on the side of the long side, is 0.7 mm. As shown in Fig. 13, The radius of curvature C2 of the ascending portion leading to the side surface is 0.8 mm. As shown in Fig. 14, the radius of curvature C of the rising portion from the bottom surface to the corner is 1.30 mm. That is, the container 33 has a structure that satisfies the formula C? CC. Further, the Vickers hardness of the opening portion is 100 Hv and the Vickers hardness of the body is 160 Hv. On the other hand, the container also serves as a negative terminal.

On the other hand, the positive electrode having the same lead tab as that of Example 1 was coated with the same co-vapor separator as in Example 1. Four sheets of this laminate and five sheets of the same negative electrodes as in Example 1 were prepared, and these were alternately stacked to prepare an electrode group. In addition, after inserting the elastic valve formed by compression molding of the synthetic rubber into the top of a cap-shaped terminal cap having a plurality of gas cylinders and a hole, a rectangular sealing plate having a gas discharging hole is inserted into the terminal, The ball was placed so as to be closed, and the flange portion of the terminal was fixed to the sealing plate by spot welding to assemble a peg member functioning as an explosion proof function and a positive terminal.

After the electrode group was housed in the container, an asphalt-based sealing agent was applied to the inner peripheral surface of the opening of the container. Subsequently, the same alkaline electrolyte as in Example 1 was injected into the vessel in the same manner as in Example 1.

(In the form of nylon 6,6) in an insulating gasket having a hole at the bottom, and the lead tab tip is welded to the lower surface of the sealing plate of the sealing member Respectively. Then, the insulating gasket was placed on the end of the container.

Then, the opening of the container was shrunk to assemble a rectangular nickel-hydrogen secondary battery having no bore shown in Fig. 15.

As shown in FIG. 15, the opening 34 of the container 33 is reduced in diameter. In the container 34, the electrode group 36 is accommodated. The electrode group 36 is formed by alternately stacking the positive electrode 39 wrapped with the negative electrode 37 and the coarse particle separator 38. The electrode group 36 is accommodated in the container 33 so that the inner circumferential surface of the container 33 is in contact with the negative electrode 37. The electrolytic solution is permeated into the electrode group 36 in the container 33. The insulating gasket 40 has a rectangular tubular shape with a bottom, and the hole 41 is opened at the bottom. The insulating gasket 41 is placed on the end portion 35 in the container 33. The sealing member (42) is disposed in the insulating gasket (40). The piercing member 42 includes the seal plate 44 having the gas discharge hole 43 and the elastic valve 45 and the terminal cap 45 having the plurality of gas passage holes 46). The elastic valve 45 is placed on the seal plate 44 so as to cover the gas discharge hole 43.

The terminal cap 46 is fixed to the sealing plate 44 so as to surround the elastic valve 45. The other end of the lead tab 47 connected to the positive electrode 39 at one end is connected to the lower surface of the sealing plate 44.

The container 33 of the rechargeable secondary battery was placed in the rectangular hole 31 of the lower mold. The curvature radii R, R and R of the lower mold satisfy the above-mentioned formula (7). Therefore, as shown in the above-mentioned FIG. 15, the container 33 is provided with a rising portion extending from the bottom surface to the side of the side of the side of the short side from the bottom inner surface of the rectangular hole 31 to the rising side As shown in Fig. 16, a rising portion extending from the bottom surface to the long side side surface is disposed at a desired distance from the rising portion leading from the bottom inner surface of the rectangular hole 31 to the long side side inner peripheral surface To the lower mold. Next, as shown in FIG. 15, a curled metal mold was disposed above the container 33. [

The curled metal mold includes a mold main body 48, a rectangular cylindrical hollow portion provided in the main body 48, and a rectangular inverted concave portion 49 having a larger dimension than the hollow portion And a knockout 50 for moving the hollow portion and the inverted concave upper portion 49 up and down. In addition, the knockout 50 has a rectangular frame-shaped protrusion 51 formed at its lower periphery. Such a curled metal mold is formed from the same material as the lower mold.

17, the curled metal mold is lowered so that the pressing plate 44 of the knockout 50 is pressed against the recessed portion 44 of the curled metal mold 49 and the upper end of the opening 34 of the container 33 are brought into contact with each other. Accordingly, the pressure is applied to the container 33, and a load is applied to the rising portion extending from the bottom surface of the container 33 to the side of the side of the short side. However, since the side of the side of the short side is high in strength, And the container 33 is supported by the rising portion leading to the side surface. As shown in FIG. 16, there is a gap in a rising portion extending from the bottom surface of the container 33 to the long side side surface and the inner surface of the bottom hole of the rectangular hole 31 to the long side side inner surface , No deformation occurred on the lower side surface of the long side of the container (33). As a result, the rising portion of the container 33 from the bottom to the corner is slightly distorted, but the upper end of the opening 34 is bent inward at a desired angle, Was tightly bonded and fixed.

The curled metal mold is removed from the container 33 by pressing the upper surface of the stopper plate 44 at the protrusion 51 of the knockout 50 while raising the curled metal mold, The container 33 was detached from the lower mold by raising the knockout 32 to produce a rectangular nickel-hydrogen secondary battery having a size of 16.4 × 5.6 × 48.0 (mm) as shown in FIG.

[Example 13]

Wherein the radius of curvature R is 1.3 mm (325% of the thickness of the container body), the curvature radius R is 0.8 mm (200% of the container body thickness) A prismatic-cell hydrogen-nickel-nickel secondary battery was produced in the same manner as in Example 12, except that the lower mold was used.

[Comparative Example 4]

A rectangular nickel-hydrogen secondary battery was produced in the same manner as in Example 12 except that the radius of curvature of the rising portion extending from the bottom inner surface of the rectangular hole to the side surface was 0.6 mm.

For the obtained secondary batteries of Examples 12 to 13 and Comparative Example 4, the external appearance of the container was observed, and the presence or absence of deformation of the curling process was examined. The results are shown in Table 3 below.

Further, for the secondary batteries of Examples 12 to 13 and Comparative Example 4, the endurance pressure was determined in the same manner as described above, and the results are summarized in Table 3 below.

As is apparent from Table 3, in the secondary batteries of Examples 12 and 13, in which the rectangular holes were manufactured using the lower mold having the shape satisfying the above formula R? RR (7), the container was free from deformation, Is higher than that of the secondary battery of Comparative Example 4. In particular, it can be seen that the secondary battery of Example 13 has a higher withstand voltage than that of the twelfth embodiment.

This is because the lower mold satisfies the formula (5) and uses the lower mold having the rectangular holes in which the R, the R are the same as the C, the C, and the R is smaller than the R. Since the lower mold has high adhesion with the rising portion that extends from the bottom surface to the side of the short side of the container, it can be stably held in the container during the curling process.

On the contrary, in the battery of Comparative Example 4, buckling deformation occurred in the container in the curling process, and the lower side surface of the long side of the container had a concave portion and the bending angle of the opening end of the container was thinner than those of Examples 12 and 13 .

On the other hand, in the twelfth and thirteenth embodiments, the lower type having knockout is used, but a lower type having no knockout may be used.

[Example 14]

First, in the fourteenth embodiment, the curled metal mold and the bottom mold used will be described with reference to FIGS. 19 to 22. FIG.

19, the lower mold 50a fixes the lower portion of the container described later in the rectangular hole.

The curled metal mold which is free to move up and down is disposed above the lower mold 50a. 20, the curled metal mold includes a mold main body 51a, a rectangular cylindrical hollow portion 52 formed in the main body 51a, and a cylindrical hollow portion 52 formed at the bottom of the hollow portion 52, Shaped recess 53 having a larger dimension than the hollow portion 52 and communicating with the hollow portion 52. [ 19, the knockout 55 in which the rectangular tabular protrusion 54 is formed on the lower peripheral edge moves up and down the hollow portion 52 and the inverted concave portion 53. 21 and 22, the inverted concave portion 53 is formed with a curled portion which abuts on the upper end of the opening of the container described later at the intersection of the side inner surface and the upper inner surface. The curvature radius r of the portion 56 located at the corner portion of the curled portion is, for example, 1.3 mm and the curvature radius r of the portion 57 located in the region except the corner is 1.0 mm, for example. Therefore, the mold has a structure in which the inverted concave portion 53 satisfies the formula (10) rr. The inverted concave portion 53 is formed with a 1.beta. Taper on its inner peripheral surface at its lower end. Such a mold is formed of a tungsten carbide alloy.

Next, the manufacturing method of the prismatic type battery will be described in detail with reference to FIGS. 19 to 22 and FIGS. 23 to 25.

First, a square-shaped rectangular nickel-hydrogen secondary battery having completed the diametral reduction process shown in FIG. 19 was assembled.

An opening 58 and a bottomed rectangular tubular container 60 formed below the opening 58 and having an inwardly projecting end 59 were prepared. The container 60 is formed by forming a rectangular barrel having a bottom by drawing on a steel plate and then expanding the opening of the rectangular barrel to form an end portion of the shape protruding inward below the opening. In addition, the container 60 has a plate thickness of 0.4 mm, a width on the lengthwise side of 16.8 mm, and a width on the side perpendicular to the lengthwise direction of 6.1 mm. Further, the Vickers hardness of the opening 58 of the container 60 is 100 Hv, and the Vickers hardness of the portion (body) located below the end portion 59 is 170 Hv. On the other hand, the container 60 also serves as a negative terminal.

On the other hand, the electrode group 61 was fabricated. The positive electrode 63 having the same lead tab 62 as in Example 1 was covered with the same coplanar gas separator 64 as in Example 1 and the laminate was divided into four pieces and Example 1 Were prepared in the same manner as in Example 1, and these were alternately stacked.

Further, a piercing member 66 serving also as an explosion-proof function and a terminal was prepared. The pivot member 66 includes a rectangular pivot plate 68 having a gas discharge hole 67; A cylindrical terminal cap 69 which is placed on the sealing plate 68 so as to enclose the gas discharging hole 67 and has a piece closed with a gas passage hole (not shown); And an elastic valve 70 disposed between the terminal cap 69 and the stopper plate 68 so as to cover the gas discharge hole 67. On the other hand, an insulating gasket 71 made of nylon 6,6 was prepared. The insulating gasket 71 has a rectangular tubular shape with a bottom, and a rectangular hole 72 at the bottom. In such an insulation gasket 71, the thickness of the rising portion is, for example, 0.5 mm, and the thickness of the bottom portion is, for example, 0.3 mm.

After the electrode assembly 61 was housed in the container 60, an asphalt-based sealing agent was applied to the inner peripheral surface of the opening 58 of the container 60. The same alkaline electrolytic solution as in Example 1 was injected into the container 60 in the same manner as in Example 1 and infiltrated into the electrode group 61. The sealing member 66 is placed in the insulating gasket 71 and the tip of the lead tab 62 is welded to the lower surface of the sealing plate 68 of the sealing member 66, 71 were mounted on the end 59 of the container 60. [ Thereafter, the opening 58 of the container 60 was shrunk.

The container 60 of the secondary battery assembled as described above was placed in the rectangular hole of the lower mold 50a and the curled metal mold was placed on the upper side of the container 60. [ Then, the curled metal mold body 51a is lowered while suppressing the stopper plate 68 from the protrusion 54 of the knockout 55. FIG.

23, since the curvature radius r of the curled portion 56 of the inverted concave portion 53 is larger than the radius r of the curled portion 57, the opening portion 58 of the container 60 The curled portion 56 of the inverted concave portion 53 of the curled metal mold is brought into contact with the corner at the upper end of the opening 58 and the corner at the upper end of the opening 58 is press- Is bent. At this time, the thickness was not shifted to the corner. 24, when the main body 51a is further lowered, the curled portion of the inverted concave portion 53 of the mold is inserted into the edge portion of the upper end of the opening portion 58 of the container 60 57 are brought into contact with each other, the edges of the upper end of the opening 58 are bent. The curled portion 57 of the inverted concave portion 53 of the curled metal mold further bends the corner at the upper end of the opening portion 58 inward. Since the corner has been bent inward in advance, the thickness of the corner pressed by the corner at the time of bending was small. Accordingly, the upper end of the opening 58 is bent into a desired shape to form a bent portion. The insulating gasket 71 is disposed in a compressed state at a position surrounded by the bent portion and the end portion 59, And the piercing member 66 is joined and fixed through the insulating gasket 71. [ The end portion 59 of the insulating gasket 71 is at the bottom peripheral edge 73 and has a length of 0.03 mm and corresponds to 10.0% of the thickness of the bottom portion of the insulating gasket 71. Also, the container 60 did not deform during the curling process.

The curled metal mold body 51a is lifted and the upper surface of the stopper plate 68 is pressed by the protrusion 54 of the knockout 55 so that the curled metal mold body 51a is pressed against the container 60 I took it off. The lower portion of the container 60 was detached from the lower mold 50a to produce a rectangular nickel-hydrogen secondary battery having a size of 16.4 × 5.6 × 48 (mm) shown in FIG.

As shown in FIG. 25, the container 60 has the opening 58 and the end 59. The upper end of the opening 58 is bent inward to form a bent portion. The electrode group 61 is formed by alternately stacking the negative electrode 65 and the positive electrode 63 wrapped with the separator 64 on the coarse aperture. The electrode group 61 is accommodated in the container 60 so that the inner circumferential surface of the container 60 and the cathode 65 are in contact with each other. And the electrolytic solution is penetrated into the electrode group 61 in the container 60. The insulating gasket 71 has a rectangular tubular shape with a bottom at which the rectangular hole 72 is opened at the bottom. The insulating gasket 71 is disposed in a compressed state at a position surrounded by the bent portion and the end portion 59 and the end portion 59 is pierced at the bottom peripheral edge 73 thereof. The depressed dimension L is 0.03 mm, which corresponds to 10.0% of the bottom thickness of the insulating gasket 59. The piercing member 66 is disposed in the insulating gasket 71 and is fixedly joined by the repulsive elastic force of the insulating gasket 71. The sealing member 66 is constituted by the rectangular sealing plate 68 having the gas discharge hole 67, the elastic valve 70 and the terminal cap 69. The elastic valve (70) is placed on the seal plate (68) so as to cover the gas discharge hole (67). The terminal cap 69 is arranged to surround the elastic valve 70 and is fixed to the sealing plate 68 by welding. The other end of the lead tab 62, which is connected to the positive electrode 63 at one end, is connected to the lower surface of the stopper plate 68.

As described above, by making the end portion 59 of the container 60 in the bottom peripheral edge 73 of the insulating gasket 71 have a length corresponding to 10% to 60% of the thickness of the insulating gasket bottom portion, When the battery is rapidly charged and gas is generated in the battery to increase the internal pressure of the battery and the central portion of the side surface of the opening 58 in the longitudinal direction is curved outward by the gas pressure, Can be prevented from deviating from the rising portion of the insulating gasket 71 above the bottom edge. Therefore, the secondary battery can improve the reliability because the airtightness can be improved.

The excellent characteristics of the prismatic battery according to the present invention were confirmed by the following experiments.

[Examples 15 to 17]

The rectangular parallelepiped shape was obtained by the same method as in Example 14 except that the recessed dimensions L were 0.05 mm, 0.10 mm and 0.18 mm, respectively (corresponding to 16.7%, 33.3% and 60% of the thickness of the bottom portion of the insulating gasket, A nickel-hydrogen secondary battery was manufactured.

[Comparative Example 5]

A curled metal mold having a curved radius of the curled portion of the square shaped inverted concave portion is 1.0 mm across the circumferential surface is used and the recessed dimension L is set to 0.02 mm (corresponding to 6.7% of the bottom thickness of the insulating gasket) A rectangular Ni-MH secondary cell was fabricated in the same manner as in Example 14 except for the above.

Further, for the secondary batteries of Examples 14 to 17 and Comparative Example 5, the endurance pressure was measured in the same manner as described above, and the results are summarized in Table 4 below.

As can be seen from Table 4, in the secondary batteries of Examples 14 to 17, in which the end portion of the container was stuck to the bottom periphery of the insulating gasket by a length corresponding to 10% to 60% of the thickness of the bottom portion of the insulating gasket, Which is higher than that of Comparative Example 5.

A rectangular Ni-MH secondary battery was produced in the same manner as in Example 14 except that the end portion of the container was punched at 0.20 mm (corresponding to 66.7% of the insulating gasket bottom thickness) at the periphery of the bottom of the insulating gasket, A deformation occurred in the lower part of the body.

[Example 18]

The material of the insulating gasket was changed to nylon 6,6 subjected to moisture absorption treatment at 50 DEG C in air having a humidity of 85% for 1 hour, and the end of the container was set at 0.17 mm Of the thickness of the nickel metal hydride secondary battery) was prepared in the same manner as in Example 14. The results are shown in Table 1. < tb > < TABLE >

The internal pressure of the obtained secondary battery of Example 18 was measured in the same manner as described above, and it was 13.5 kg / cm ~ 15.0 kg / cm Respectively.

Although the curled metal mold having knockout is used in Examples 14 to 18, a curled metal mold having no knockout may be used.

In Examples 1 to 18, as the explosion-proof function, when the gas pressure in the battery becomes equal to or greater than a predetermined value, the valve is opened to discharge the gas to the outside, and thereafter, Although an elastic valve is used, as the explosion-proof mechanism, a valve membrane which is a non-return type safety valve may be used. The valve membrane may be disposed between the sealing plate and the anode terminal so as to cover the gas discharge hole of the sealing plate.

In Examples 1 to 18 described above, an example in which the present invention is applied to a rectangular nickel-hydrogen secondary battery is described, but the present invention can be similarly applied to a rectangular nickel cadmium secondary battery, a rectangular type lithium ion secondary battery, and a rectangular type lithium battery.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to provide a method of manufacturing a prismatic battery, which can improve the internal pressure of the seal, prevent the container dimensions from being matched, and improve the yield.

According to another manufacturing method of the prismatic battery according to the present invention, the container can be supported by the lower mold without deforming the container in the curling process, and the opening end of the container is bent inward at a desired angle It is possible to attach the sealing member to the container with good airtightness, and to improve the airtightness and reliability of the prismatic battery.

INDUSTRIAL APPLICABILITY The prismatic battery according to the present invention exhibits remarkable effects such as improved sealing resistance and improved reliability.

Further, according to the manufacturing method of the prismatic battery of the present invention, it is possible to provide a prismatic battery which can prevent the body and the bottom of the container from being deformed in the curling process, and the sealing pressure and reliability can be improved.

Claims (12)

A step of accommodating an electrode group in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening, the container being manufactured by opening an opening of a bottomed rectangular container, The electrode group is manufactured by interposing a separator between the cathode and the anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; And a step of bonding and fixing the sealing member to the container through the insulating gasket by bending the upper end of the opening part inward after reducing the diameter of the opening part of the container, Expression W _x > W _y (1) Of the first conductivity type. In the above formula (1), W _x is the diametral reduction of the opening in the direction perpendicular to the longitudinal direction, W _y is the diametral reduction of the opening in the longitudinal direction, and , And W _y is 30 to 60% of the thickness of the container. 2. The apparatus according to claim 1, wherein a width of the opening when the opening of the rectangular tub having the bottom is extended is set to be, The formula A _x > A _y (2) Of the total weight of the battery. In the above formula (2), A _x is a widening width when the opening is extended in a direction orthogonal to the longitudinal direction, A _y is a widening width when the opening is extended in the longitudinal direction, , And A _y is 30 to 60% of the container thickness. The apparatus according to claim 2, Expression L ₁ > L ₂ (3) Of the total weight of the prismatic battery. In the formula (3), L ₁ represents the thickness of the opening in the longitudinal direction, and L ₂ represents the thickness of the opening perpendicular to the longitudinal direction. A step of accommodating an electrode group in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening; the electrode group is manufactured by interposing a separator between a cathode and an anode; Receiving an electrolyte solution in the vessel; Placing the sealing member and the insulating gasket accommodating the sealing member on the end portion of the container; Sidewalling the opening of the container; And joining and fixing the sealing member to the container through the insulating gasket by bending the upper end of the opening inward while inserting the lower portion of the container into the rectangular hole of the lower mold, R ₃ &_gt; R ₂ > R ₁ (4) Of the total weight of the prismatic battery. In the formula (4), R ₁ represents the radius of curvature of the rising portion connected from the inner bottom surface of the rectangular hole to the inner surface of the long side, and R ₂ represents the radius of curvature of the connecting portion from the inner bottom surface of the rectangular hole to the inner surface of the short side Wherein R ₃ represents the radius of curvature of the rising portion connected to the corner portion from the inner surface of the bottom of the rectangular hole. A container having a rectangular tubular shape with a bottom and having a bent portion formed by bending the opening portion and an upper end of the opening portion inwardly and an end portion protruding inwardly formed below the opening portion; An electrolytic solution accommodated in the container and made by interposing a separator between a cathode and an anode; An electrolyte contained in the vessel; An insulating gasket arranged in a compressed state in a position wrapped by the bent portion and the end portion in the container; the insulating gasket being in the shape of a rectangular tubular with a bottom, and having a hole at the bottom where the end is in contact; And a sealing member which is disposed in the insulating gasket and which is fixedly joined to the container under the compression of the insulating gasket, wherein the insulating gasket is formed such that the end thereof is located at 10% to 60% of the thickness of the bottom of the insulating gasket Wherein the protruding portion has a length corresponding to a length thereof. The prismatic battery according to claim 5, wherein the gasket is formed of hygroscopic nylon 6,6. A step of accommodating an electrode group in a bottomed rectangular tubular container having an opening and an end protruding inwardly formed below the opening; the electrode group is manufactured by interposing a separator between a cathode and an anode; Receiving an electrolyte solution in the vessel; Placing an insulated gasket in which the piercing member and the piercing member are housed in the end portion of the container, the insulated gasket being in the form of a rectangular tubular with a bottom, the end having a hole at the bottom to which it is abutted; Shrinking the opening of the container; And the end portion of the opening is folded inwardly by a curled metal so that the sealing member is fixedly joined to the container, and the end portion is formed at the periphery of the bottom of the insulating gasket by a length corresponding to 10% to 60% Wherein the curled metal mold has a rectangular inverted concave portion at the bottom of the metal mold body and the inverted concave portion is curled at the intersection of the inner side surface of the mold and the inner surface of the upper portion, And further, Equation r ₁ > r ₂ (5) Of the total weight of the prismatic battery. In the formula (5), r ₁ represents the radius of curvature of the corner portion of the curled portion, and r ₂ represents the radius of curvature of the curled portion and the region excluding the corner portion. 8. The method of manufacturing a prismatic battery according to claim 7, wherein the inverted concave portion is formed with a batten taper having an angle of 0.5 DEG to 10 DEG with respect to the inner peripheral surface of the lower end thereof. The method according to claim 7, wherein the electrolytic solution receiving step is performed by dividing and injecting the electrolytic solution into the container at least two times, and the final injection is performed while applying centrifugal force acting on the bottom of the container Wherein the method comprises the steps of: 10. The method of manufacturing a prismatic battery according to claim 9, wherein the inside of the container is left at a reduced pressure immediately before the final injection. The method according to claim 1, wherein the electrolytic solution receiving step is performed by dividing and injecting the electrolytic solution into the container at least two times, and the final injection is performed while applying a centrifugal force acting on the bottom of the container Wherein the method comprises the steps of: 5. The method according to claim 4, wherein the electrolytic solution receiving step is performed by dividing and injecting the electrolytic solution into the container at least two times, and the final injection is performed while applying centrifugal force acting in the direction of the bottom of the container Wherein the method comprises the steps of: