JP2000077054A - Battery and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce warp of an electrode plate in which a belt-shaped metal sheet is welded to the exposed part of a substrate and extremely reduce internal short circuit in the state actually assembled as a battery. SOLUTION: A battery has an electrode group formed by stacking a first electrode plate and a second electrode plate comprising a positive electrode plate and a negative electrode plate respectively through a separator, an outer can for housing the electrode group, and a current collecting plate electrically connected to the first electrode plate and electrically connecting the first electrode plate to one terminal. The first electrode plate is a non-sintered electrode in which an active material is filled in a metal three-dimensional porous body, and has a substrate exposed part 7 in which the substrate is exposed. A belt- shaped metal sheet 10 is welded to the substrate exposed part 7, and the belt- shaped metal sheet 10 is welded to the current collecting plate. The belt-shaped metal sheet 10 has a plurality of cut parts 14 at specified intervals. The cut parts 14 cut off a welding edge 10A to be welded to the current collecting plate, and an active material filling side edge 10B on the opposite side of a welding edge 10A is continuously installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery in which a strip metal sheet is welded to a three-dimensional porous metal substrate, and a current collector plate is connected to the strip metal sheet to improve the high rate discharge characteristics, and to manufacture the battery. About the method.

[0002]

2. Description of the Related Art Sintered electrodes and non-sintered electrodes are used as electrode plates for alkaline batteries and the like. Conventionally, sintered electrodes have been widely used. This electrode is manufactured by impregnating a carbonyl nickel sintered body with a solution such as a nickel salt or a cadmium salt, and performing an alkali treatment to make it an active material. However, in recent years, non-sintered electrodes have become promising because they can reduce the cost and increase the energy density. The non-sintered electrode is manufactured by using a three-dimensional metal porous body such as foamed nickel or a porous nickel fiber as a substrate, and directly filling a gap of the substrate with a paste-like active material.

Since non-sintered electrodes use a metal three-dimensional porous body for the substrate, they cannot be connected by welding a lead plate directly to the substrate, as in the case of punching metal used for the substrate of a sintered electrode. . This is because most of the three-dimensional metal porous body is a void, and the ratio of the metal part is extremely small, so that even if the lead plate is brought into contact, the contact area is extremely small.

A technique for connecting a metal three-dimensional porous substrate to a current collector is described in the following publication. JP-A-63-4562 JP-A-2-220365

According to the publication, a substrate exposed portion which is not filled with an active material is provided along an edge of a metal three-dimensional porous substrate, a strip-shaped thin metal plate is welded to the exposed portion, and this portion is connected to a current collector plate. Is described.

The electrode plate in which the strip-shaped metal sheet is welded to the exposed portion of the substrate is spirally wound through a separator to form an electrode group. As shown in the exploded view of FIG. 1, the spiral electrode group can collect the current by welding the current collector 6. As shown in this figure, the battery in which the current collector plate 6 is welded to the electrode group 4 can improve the high-rate discharge characteristics and the discharge characteristics at a large current.

However, when a strip-shaped metal sheet is welded to the exposed portion of the substrate, the thermal expansion and contraction of the three-dimensional porous metal body and the strip-shaped metal sheet do not match, as shown in FIG.
There is a problem in that the edge where the band-shaped metal sheet 10 is welded shrinks and the electrode plate warps, making it impossible to manufacture a uniform product.
The strip-shaped metal sheet 10 is welded to the exposed substrate portion 7 of the substrate 9 by ultrasonic welding or resistance electric welding. Although resistance electric welding is excellent in production efficiency, the warpage of the electrode plate becomes severe. This is because the heat generated during resistance electric welding causes the contraction of the strip-shaped metal sheet 10 to increase.

As shown in FIG. 2, the position of the warped electrode plate shifts when the other electrode plate is laminated via a separator. In addition, if these are stacked and wound in a spiral shape, a winding shift occurs, and it becomes impossible to align the end faces of the spiral electrode group in a planar shape. An electrode group having a winding deviation is liable to cause an internal short circuit when the current collector plate is pressed and welded.
This is because the protruding portion is crushed by the current collector plate and breaks through the separator.

In order to solve this drawback, a battery has been developed in which a strip-shaped thin metal plate having a staggered cut portion is welded to an exposed portion of a substrate (Japanese Patent Application Laid-Open No. Sho 64-71064). In the battery described in this publication, as shown in FIG. 3, cut portions 14 are provided in a staggered manner on both sides of a strip-shaped thin metal plate 10. The electrode plate obtained by welding the strip-shaped thin metal plate 10 of this shape to the exposed portion of the substrate can reduce the warpage.

[0010]

However, a battery obtained by welding a strip-shaped metal sheet having this structure to an exposed portion of a substrate has a high probability of causing an internal short circuit in an actually assembled state, and has a disadvantage that the product yield is deteriorated. Was. Although the present inventors can reduce the warpage of the electrode plate to which the strip-shaped metal sheet is welded by the staggered cut portions, the inventors have not been able to determine how the internal short circuit occurs in the assembled state. A spiral electrode group formed by laminating and winding electrode plates without warpage,
This is because the end faces can be aligned in a plane.

The present inventors have further repeated various trials and errors, and as a result, have found that an internal short circuit has occurred due to a completely different cause, and completed the present invention. Therefore,
An important object of the present invention is to provide a battery capable of minimizing internal short-circuits in a state actually assembled as a battery, in addition to being able to reduce the warpage of an electrode plate by welding a strip-shaped metal sheet to an exposed portion of a substrate and a method of manufacturing the same. Is to provide.

[0012]

A battery according to the present invention comprises an electrode group 4 in which a first electrode plate 1 and a second electrode plate 2 each comprising a positive electrode plate and a negative electrode plate are laminated with a separator 3 interposed therebetween. 4 and a current collector plate 6 electrically connected to the first electrode plate 1 and electrically connecting the first electrode plate 1 to one terminal. The first electrode plate 1 is a non-sintered electrode in which an active material is filled in a metal three-dimensional porous substrate 9 and has a substrate exposed part 7 exposing the substrate 9. The strip-shaped metal sheet 10 is welded to the substrate exposed portion 7, and the strip-shaped metal sheet 10 is welded to the current collector 6. Further, the strip-shaped metal sheet 10 to be welded to the substrate exposed portion 7 is provided with a plurality of cut portions 14 at predetermined intervals.
Is provided. The cut portion 14 is provided in a state where the welding edge 10A to be welded to the current collector plate 6 is cut off, and the active material filling side edge 10B opposite to the welding edge 10A is continuous.

Further, in the battery according to the second aspect of the present invention, the cut portion 14 is any one of a straight line, a circle, an ellipse, a chicken egg, and a triangle.

Further, in the battery according to the third aspect of the present invention, the depth of the cut portion 14 is set to be 3 times the entire width of the strip-shaped metal sheet 10.
0% or more and less than 100%.

Further, in the battery according to the fourth aspect of the present invention, the interval between the adjacent cut portions 14 is set to 50 mm or less.

Further, in the battery according to the fifth aspect of the present invention, the total length of the opening width of the cut portion 14 at the welding edge 10A is less than 10% of the entire length of the strip-shaped thin metal plate 10.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a battery, wherein the substrate is a metal three-dimensional porous body filled with an active material.
Edge 10 to be welded to current collector plate 6
A is cut off at a predetermined interval, and a strip-shaped thin metal plate 10 provided with a plurality of cut portions 14 at a predetermined interval so as to connect the active material filled side edge 10B opposite to the welding edge 10A is welded to an electrode plate. And a lamination step of laminating the second electrode plate 2 via the separator 3 on the first electrode plate 1 to which the strip-shaped thin metal plate 10 is welded, to produce an electrode group 4, and a first step of forming the first electrode group 4. A step of welding the current collector plate 6 to the strip-shaped thin metal plate 10 provided on the electrode plate 1, and a step of welding the electrode group 4 formed by welding the current collector plate 6 to the outer can 5.
, A step of injecting the outer can 5, and a step of closing the opening of the outer can 5.

According to a seventh aspect of the present invention, there is provided a method for manufacturing a battery, comprising the steps of:
Edge 10 to be welded to current collector plate 6
A is cut off at a predetermined interval, and a strip-shaped thin metal plate 10 provided with a plurality of cut portions 14 at a predetermined interval so as to connect the active material filled side edge 10B opposite to the welding edge 10A is welded to an electrode plate. , A cutting step of cutting the strip-shaped metal sheet at a predetermined width along the welding edge, and a second electrode plate 2 with the separator 3 interposed between the first electrode plate 1 obtained by cutting the strip-shaped metal sheet 10. Are laminated to form an electrode group 4, a step of welding the current collector 6 to the strip-shaped thin metal plate 10 provided on the first electrode plate 1 of the electrode group 4, and a step of welding the current collector 6. Electrode group 4
And a step of pouring the liquid into the outer can 5 and a step of closing the opening of the outer can 5.

Further, in the battery manufacturing method according to the eighth aspect of the present invention, in the cutting step, the strip-shaped metal sheet 10 is cut to a width from which the cut portion 14 is removed.

According to a method of manufacturing a battery according to a ninth aspect of the present invention, a substrate exposed portion 7 of a three-dimensional porous metal substrate 9 filled with an active material is provided, and a strip-shaped metal sheet 10 is provided on the substrate exposed portion 7. And a welding step of manufacturing the first electrode plate 1 by cutting off the welding edge 10A of the strip-shaped metal sheet 10,
In a state where the active material-filled side edge 10B opposite to the welding edge 10A is continuous, a cutting step of providing a plurality of cut portions 14 at predetermined intervals, and a separator 3 on the first electrode plate 1 obtained by cutting the strip-shaped metal sheet 10. A laminating step of manufacturing the electrode group 4 by laminating the second electrode plate 2 through a step of welding the current collector plate 6 to the strip-shaped metal sheet 10 provided on the first electrode plate 1 of the electrode group 4; Plate 6
Inserting the electrode group 4 formed by welding into the outer can 5;
It comprises a step of injecting the outer can 5 and a step of closing the opening of the outer can 5.

Furthermore, the method for manufacturing a battery according to claim 10 of the present invention is directed to a method of manufacturing a battery, comprising:
Is any of a straight line, a circle, an ellipse, a chicken egg, and a triangle.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a battery for embodying the technical idea of the present invention and a manufacturing method thereof, and the present invention does not specify the battery and the manufacturing method thereof as follows.

Further, in this specification, in order to facilitate understanding of the claims, the numbers corresponding to the members described in the embodiments will be referred to as "claims" and " In the column of “Means of the above”. However, the members described in the claims are not limited to the members of the embodiments.

The battery shown in FIG. 4 has a cylindrical outer can 5 hermetically sealed with a sealing plate 11, an electrode group 4 inserted into the outer can 5, and a terminal of the outer can 5 And a current collecting plate 6 connected to the power collecting plate 12. Although the battery shown in the figure has a cylindrical outer can 5, the present invention does not specify the cylindrical outer can of the battery. Although not shown, the outer can can be, for example, a square tube or an elliptical tube.

The outer can 5 is made of iron and its surface is plated with nickel. As the material of the outer can 5, an optimal metal is selected in consideration of the type and characteristics of the battery. The outer can, for example,
It may be made of stainless steel, aluminum, or aluminum alloy. The metal outer can 5 has an opening at the upper end hermetically sealed with a sealing lid. The sealing lid is air-tightly fixed by a method of caulking the outer can 5, or a method of laser welding the boundary between the outer can and the sealing lid. The sealing plate 11 fixes one terminal 12 of the battery. This terminal 12
Is insulated and fixed to the outer can 5.

The battery of the present invention is a battery containing a non-sintered electrode, for example, a nickel-hydrogen battery. However, the present invention does not specify a battery as a nickel-metal hydride battery. The battery may be, for example, a nickel-cadmium battery, a lithium ion battery, or the like. Hereinafter, an embodiment of a nickel-hydrogen battery will be described in detail as a preferred embodiment.

The electrode group 4 includes a first electrode plate 1 and a second electrode plate 2,
It is wound via a separator 3. The battery shown in the figure is
The first electrode plate 1 connected to the current collector plate 6 is a positive electrode plate, and the second electrode plate 2 is a negative electrode plate. However, in the present invention, the first electrode plate may be a negative electrode plate and the second electrode plate may be a positive electrode plate. First electrode plate 1 stacked on each other via separator 3
And the second electrode plate 2 are wound to produce a spiral electrode group 4. The spiral electrode group 4 is inserted into a cylindrical outer can 5. The spiral electrode group can be pressed from both sides, deformed into an elliptical shape, and inserted into an elliptical outer can. Further, the electrode group to be inserted into the rectangular cylindrical outer can is manufactured by laminating a plurality of first electrode plates and second electrode plates cut into a plate shape via a separator.

As the separator 3, a nonwoven fabric made of polyolefin is used. However, a microporous membrane made of a synthetic resin such as polyethylene can be used for the separator 3. As the separator 3, any sheet material that can insulate the first electrode plate 1 and the second electrode plate 2 laminated on both sides and can penetrate the electrolyte can be used.

The first electrode plate 1 is made of a metal three-dimensional porous substrate 9.
This is a non-sintered electrode in which an active material is filled. The metal three-dimensional porous substrate 9 is a foamed nickel porous body, a nickel fiber porous body, or the like. The first electrode plate 1 has these substrates 9 filled with an active material.

As shown in the development view of FIG. 5, the substrate of the first electrode plate 1 is provided with a substrate exposed portion 7 on the upper portion of a substrate 9 and the other portion is filled with an active material filled portion 8 filled with an active material. And The substrate exposure part 7 is not filled with the active material, or the filled active material is removed to expose the substrate 9. The substrate 9
Preferably, it is pressed at the substrate exposed portion 7 and compressed at a high density. The compressed substrate exposed portion 7 has a feature that the strip-shaped metal sheet can be reliably welded.

As shown in the sectional view of FIG. 6, a strip-shaped thin metal plate 10 is fixed to the substrate exposed portion 7 in order to surely electrically connect the current collector plate 6 to the substrate. The strip-shaped metal sheet 10 is subjected to resistance electric welding or ultrasonic welding to form the substrate exposed portion 7.
Is adhered in a state of being electrically connected to the.

The strip-shaped metal thin plate 10 is a nickel thin plate, a phosphorus nickel thin plate, or a thin plate obtained by plating nickel on iron, and has a thickness of 0.05 mm or more and less than 80% of the thickness of the first electrode plate 1. If the strip-shaped metal sheet is thinner than 0.05 mm, the strength when welding the exposed portion of the substrate to the current collector plate becomes insufficient. Conversely, when the thickness of the strip-shaped metal sheet is greater than 80% of the first electrode plate, the exposed portion of the substrate becomes thicker in a state where the first electrode plate and the second electrode plate are stacked with the separator interposed therebetween. Space efficiency is reduced. The thickness of the strip-shaped metal sheet 10 is preferably 0.08 to 0.2 mm.

The strip-shaped metal sheet 10 has cut portions 14 at predetermined intervals. The strip-shaped metal sheet 10 of FIG. 7 has a straight cut portion 14. The cutting portion 14 cuts off a welding edge 10A (upper edge in FIG. 7) to be welded to the current collector plate, and cuts the active material-filled side edge 10B opposite to the welding edge 10A.
(Lower edge in FIG. 7) is provided on the strip-shaped metal sheet 10 in a continuous state. As shown in FIG. 8, the strip-shaped metal thin plate 10 of FIG. 7 is welded to the substrate exposed portion 7 of the substrate 9.

Further, the battery according to the present invention has
As shown in FIGS. 9 to 11, a circular, oval, or triangular cut portion 14 may be provided at 0. In addition, as shown in FIG. 12, cutting portions 14 having various shapes can be provided in a mixed manner. Further, although not shown, a cut portion such as a chicken egg shape can be provided.

The depth of the cut portion 14 is specified to be 30% or more and less than 100% of the entire width of the strip-shaped metal sheet 10. If the cut portion is shallower than 30%, the warpage of the electrode plate cannot be effectively prevented when the strip-shaped thin metal plate 10 is welded to the substrate exposed portion 7 of the substrate 9. Further, when the cut portion 14 is extended to the active material filling side edge 10B, internal short-circuits increase in a state where the battery is assembled.

Further, the interval between the cut portions 14 is specified to be 50 mm or less. If the interval between the cut portions 14 is too wide, the warpage of the electrode plate cannot be effectively prevented when the strip-shaped metal sheet 10 is welded to the substrate exposed portion 7. Further, the strip-shaped metal sheet 10 shown in FIG. 7 and FIGS.
Although the strips 4 are provided at equal intervals, the strip-shaped metal sheet may be provided with cut portions at irregular intervals within the above range.

Further, as shown in FIGS. 9 to 12, the strip-shaped thin metal plate 10 having an opening at the welding edge 10A by the cutting portion 14 has a total length of the opening width of the cutting portion 14 at the welding edge 10A. And less than 10% of the entire length of the strip-shaped metal sheet 10. If the opening width is wider than this, the number of welding points of the current collector decreases, and the electric resistance between the strip-shaped thin metal plate 10 and the current collector increases.

The strip-shaped metal thin plate 10 is preferably provided with a cut portion 14 and welded to the substrate exposed portion 7 of the substrate 9. However, after the strip-shaped metal sheet is welded to the exposed part of the board,
A cutting section can also be provided. In the method of providing a cut portion on the strip-shaped metal sheet welded to the substrate exposed portion, the cut portion is provided by cutting both the strip-shaped metal sheet and the substrate exposed portion.

Further, in the battery of the present invention, as shown in FIG. 13, after the strip-shaped thin metal plate 10 having the cut portion 14 is welded to the substrate exposed portion 7, the portion having the cut portion 14 is cut and removed. Can also. Strip metal sheet 1 cut after welding
0, as shown in the figure, the portion provided with the cut portion 14 is welded so as to protrude from the substrate exposure portion 7, and then cut at the position indicated by the dashed line to remove the portion provided with the cut portion 14. . Further, as shown in FIG. 14, a strip-shaped thin metal plate 10 having a cut portion 14 is welded to the widened substrate exposed portion 7,
Thereafter, cutting can be performed from the position indicated by the chain line. The strip-shaped metal sheet 10 having such a structure has no cut portion 14 in a state where the current collector plate is welded. For this reason, there is a feature that welding can be performed on the current collector plate in an ideal state. However, in the battery of the present invention, the current collector plate can be welded by cutting the strip-shaped metal thin plate while leaving some cut portions.

As shown in FIG. 6, a protective tape 13 is adhered to both sides of the substrate 9 to which the strip-shaped thin metal plate 10 is welded. The protective tape 13 has a lower edge extending below the active material-filled side edge 10B. The electrode plate having this structure is for preventing the active material-filled side edge 10B from bending and breaking through the separator 3 when the current collector plate 6 is pressed and welded to the substrate exposed portion 7 and the strip-shaped metal thin plate 10. . Protective tape 13
The current collector plate 6 can be welded to the substrate exposed portion 7 and the strip-shaped thin metal plate 10 by preventing the internal short circuit in the battery to which is bonded.
However, the exposed portion of the substrate can be connected to the current collector plate without using the protective tape.

The current collecting plate 6 is a metal plate obtained by plating nickel on iron or a metal plate such as a nickel plate. As shown in FIG. And the lead plate 6A is projected. The current collectors 6 are provided so as to face each other at both ends of the electrode group 4. The current collector plate 6 shown in FIG. 15 has a circular shape for use in a battery in which the battery outer can 5 has a cylindrical shape. However, since the battery of the present invention is not specified as a cylindrical battery, for example, although not shown, A rectangular current collector plate can be used for the battery.

The current collector plate 6 is provided with slits 6C on both sides of the center hole 6B in order to reduce the reactive current at the time of resistance electric welding. Further, a plurality of through holes 6D are opened. As shown in the enlarged sectional view of FIG. 16, a projection 6E projecting downward is provided on the periphery of the through hole 6D. The projection 6E is connected to the substrate exposed portion 7 of the first electrode plate 1 by welding at a plurality of portions. The lead plate 6A of the current collector plate 6 is
Is connected to a terminal 12 which is insulated and fixed to the opening of the second terminal.

When welding the substrate exposed portion 7 and the strip-shaped metal thin plate 10 to the current collector 6, it is important that the substrate exposed portion 7 and the strip-shaped metal thin plate 10 are uniformly contacted with the current collector 6. In a state where the current collector plate 6 is locally pressed by the welding electrode rod, even if the current collector plate 6 is not deformed at all, or if the deformation is too large, the welded portion cannot be uniformly contacted. If the deformation is too large, the welded portion in the vicinity of being pressed by the welding electrode rod is strongly pressed, but the contact of the welded portion at a portion away from the welding electrode rod is weak or separated. If the current collecting plate 6 is not deformed at all, only the protruding welding portion of the current collecting plate 6 and the substrate exposed portion 7 comes into strong contact, and the other welding portions do not come into contact. For this reason, it becomes impossible to bring all the welded portions into uniform contact and weld in an ideal state.

[0044]

EXAMPLE In the following steps, a cylindrical nickel-hydrogen battery of SC size was prototyped, and the shape of the strip-shaped metal sheet was changed.
The electrode plate warpage and internal short were measured.

In the following steps, an electrode group to be inserted into an outer can of a nickel-hydrogen battery was manufactured. a. Production of positive electrode plate as first electrode plate (1) A porous metal body is produced in the following steps. The sponge-like organic porous body, which is an open-celled polyurethane foam, is subjected to a conductive treatment and then immersed in a plating solution in an electrolytic cell for plating. The plated organic porous body is roasted at a temperature of 750 ° C. for a predetermined time to remove a resin component of the organic porous body, and then sintered in a reducing atmosphere to produce a metal porous body. The porous metal body manufactured in this step has a basis weight of about 600 g /
m ² , a porosity of 95%, and a thickness of about 2.0 mm.

(2) The following are kneaded to prepare an active material slurry for the positive electrode. Nickel hydroxide powder 90 parts by weight (containing 2.5 wt% of zinc and 1 wt% of cobalt as a coprecipitating component) Cobalt powder ... ... 10 parts by weight zinc oxide powder ... 3 parts by weight hydroxypropylcellulose 0.2 parts by weight % Aqueous solution ... 50 parts by weight

(3) The prepared positive electrode active material slurry is
The voids of the porous metal body were filled. The filling amount was adjusted so that the active material density after roll rolling was about 2.91 g / cc-void. Then, dried, about 0.70mm thick
Roll rolling was performed so that Further cut into strips, and exposed to the substrate exposed portion 7 to which the strip-shaped metal sheet 10 is welded,
The active material was removed by ultrasonic peeling or the like in which ultrasonic vibration in the vertical direction was applied. Then, as shown in FIG. 5, the first electrode plate 1 having the substrate exposed portion 7 from which the substrate 9 is exposed is obtained.

In the first electrode plate, a substrate exposed portion can be manufactured by the following steps. As shown in FIG. 17, before the active material is filled, a part of the porous metal body, which becomes the substrate exposed part 7, is roll-rolled in parallel with a predetermined width. The width of the roll rolling is set to about 6 mm, which is twice the width of the substrate exposed portion 7,
The thickness after rolling is 0.5 mm. The above-mentioned active material slurry is filled into the rolled porous metal substrate 9 and rolled. Thereafter, the first electrode plate 1 is cut at the position indicated by the arrow in FIG. After that, the active material is removed along with the thinly rolled portion serving as the substrate exposed portion 7 by blowing compressed air or using a brush or the like to expose the substrate 9.

(4) In the exposed substrate exposed portion 7 of the substrate 9,
The strip-shaped metal sheet 10 is bonded by resistance electric welding. The substrate exposed portion 7 and the strip-shaped metal sheet 10 were subjected to resistance electric seam welding at a pressure of 10 kgf. A nickel ribbon having a thickness of 0.1 mm was used for the strip-shaped metal sheet 10, and its width was set to 3 mm.

B. Production of negative electrode plate as second electrode plate (1) Production and pulverization of hydrogen storage alloy Misch metal (mixture of rare earth elements such as La, Ce, Nd, Pr), nickel, cobalt, aluminum and manganese , With an elemental ratio of 1.0: 3.4: 0.8:
The mixture is weighed in a ratio of 0.2: 0.6, mixed, put into a crucible, melted in a high frequency melting furnace, and then cooled to produce a hydrogen storage alloy electrode having the following composition formula. And _{Mm 1.0 Ni 3.4 Co 0.8 Al 0.2} Mn 0.6, an ingot of the resulting hydrogen absorbing alloy, after previously roughly pulverized, the average particle size in an inert gas is pulverized so that 60 [mu] m.

(2) Preparation of Hydrogen Storage Alloy Slurry Polyethylene oxide powder is added as a binder to the pulverized hydrogen storage alloy powder, and ion-exchanged water is further added and kneaded to form a slurry. The added amount of the polyethylene oxide powder as the binder is 1.0% by weight based on the hydrogen storage alloy.

(3) The slurry was applied to both surfaces of a substrate which was a punching metal. The coating amount was adjusted so that the active material density after rolling was 5 g / cc. Then, after performing drying and rolling, it was cut to a predetermined size to obtain a negative electrode plate as the second electrode plate 2. The slurry was applied leaving a lower edge so that an exposed portion of the substrate was formed on a lower edge of the punched metal.
Alternatively, after the slurry is applied to the entire surface of the punching metal, the slurry is dried, and the active material on the lower edge is removed to provide an exposed portion of the substrate.

The first electrode plate 1 and the second electrode plate 2 manufactured in the above steps are separated from the separator 3 made of a polyolefin nonwoven fabric.
To form a spiral electrode group 4 to form a spiral electrode. The current collector 6 is welded to the strip-shaped metal sheet 10 projecting from the upper end of the spiral electrode by resistance electric welding. As the current collecting plate 6, a disc-shaped nickel-plated iron plate having a thickness of 0.40 mm was used.

Using the first electrode plate 1 and the second electrode plate 2 manufactured by the above method, a cylindrical nickel-hydrogen battery was experimentally manufactured. The prototype battery was manufactured by changing the shape of the strip-shaped metal sheet 10 used for the first electrode plate 1 as follows.
The amount of warpage of the electrode plate and the number of internal short circuits were inspected. The amount of warpage of the electrode plate is determined by setting the strip-shaped metal sheet 10
Was measured as shown in FIG.

[Examples 1 to 8] The cut portions of the strip-shaped metal sheet were determined as shown in Table 1, and 100 first electrode plates were prototyped. Using 100 first electrode plates, 100 electrode groups were prototyped. A group of 100 electrodes was selected without any displacement and inserted into an outer can to assemble a battery. Since only the electrode group having no winding deviation was inserted into the outer can and assembled as a battery, the number of batteries is not necessarily 100 in each embodiment. For example, when the 30 electrode groups out of 100 electrode groups are misaligned, the remaining 70 electrode groups were assembled and the number of short-circuited batteries was inspected. Similarly, in the batteries of the following Examples and Comparative Examples, only an electrode group having no winding deviation was selected and inserted into an outer can to assemble the batteries.

In the batteries of Examples 1 to 8, the cut portions of the strip-shaped sheet metal were straight as shown in FIG. 7, and the cut portions had different depths and intervals. The depths and intervals of the cut portions of the strip-shaped metal sheet used in the batteries of Examples 1 to 8 were determined as shown in Table 1.

[0057]

[Table 1]

Further, in order to compare how the battery of the embodiment of the present invention shows excellent characteristics, the battery was cut in the same manner as in the above embodiment except that the cut portion of the strip-shaped metal sheet was changed as follows. And the batteries of Comparative Examples 1, 2, and 3. [Comparative Example 1] First using a strip-shaped metal sheet without a cut portion
An electrode plate was prepared, and a battery was prototyped in the same manner as in Example 1 using the first electrode plate. [Comparative Example 2] A first electrode plate was prepared by using a strip-shaped metal sheet provided with cut portions having a depth of 2 mm at intervals of 30 mm.
A battery was prototyped using this first electrode plate. The cut portion was provided so as to cut off the active material-filled side edge on the opposite side without cutting off the weld edge. [Comparative Example 3] A strip-shaped thin metal plate in which cut portions having a depth of 2 mm were provided in a zigzag manner at intervals of 30 mm was manufactured, and a battery was manufactured using the first electrode plate.

Table 2 shows the amount of warpage of the first electrode plate prototyped as described above and the number of short circuits in the battery using the first electrode plate.

[0060]

[Table 2]

As is clear from this table, the battery of the present invention has a small amount of warpage of the electrode plate, and has a small winding deviation and an internal short circuit. In the battery of Comparative Example 3 using the strip-shaped thin metal plate in which the cut portions were provided in a staggered manner, the amount of warpage of the electrode plate was reduced.
As much as 28% of the batteries were short-circuited internally when assembled as batteries. Further, in the battery of Comparative Example 2 using a strip-shaped thin metal plate in which the cut portion was provided so as to separate the active material-filled side edge, the amount of warpage of the electrode plate was reduced, but as many as 33 batteries were short-circuited internally.

If the cut portion provided in the strip-shaped metal sheet is shallow, the amount of warpage of the electrode plate increases, the winding shift increases, and an internal short-circuit easily occurs. In order to test a winding deviation and an internal short circuit with respect to the depth of the cut portion, a battery was provided in the same manner as in the above-described embodiment using a strip-shaped thin metal plate provided with a cut portion having a depth of 30% or less. Prototype made. As a result, when the width of the cut portion is 30% or less, the winding deviation increases,
The percentage of internal shorts has increased. For this reason, in the battery of the present invention, it is desirable that the depth of the cut portion provided in the band-shaped metal sheet is 30% or more of the entire width of the band-shaped metal sheet.
Further, when the depth of the cut portion is set to 100%, the cut portion is extended to the active material filling side edge.
Shallower than 0%.

Further, even if the interval between the cut portions provided on the strip-shaped metal sheet is wide, the amount of warpage increases, the winding displacement of the electrode plate increases, and an internal short-circuit easily occurs. In order to test the amount of warpage, winding deviation, and internal short-circuit with respect to the interval between adjacent cut portions, a strip-shaped metal sheet provided with a cut portion having an interval of 50 mm or more was used, as in the above-described embodiment. A prototype battery was manufactured. As a result, the interval between the cut portions is 5
If it exceeds 0 mm, the amount of warpage and the winding deviation increase, and the ratio of internal short-circuiting increases. From this, the battery of the present invention has a gap of 50 m between the cut portions provided on the strip-shaped metal sheet.
m or less.

Further, the shapes of the cut portions were changed, and the batteries of the following examples were prototyped. The batteries of the following examples were prototyped in the same manner as the batteries of the above-described examples except that the shape of the cut portion was changed.

[Examples 9 and 10] In the batteries of Examples 9 and 10, the cut portions of the strip-shaped sheet metal were formed into regular triangles as shown in FIG. 11 and cut portions having different depths were used. The depth of the cut portion of the strip-shaped metal sheet used in the batteries of Examples 9 and 10 was determined as shown in Table 3. The length of one side of the triangle as the cut portion was 1 mm. In addition, the interval between the cut portions is 30.
mm.

The depth of the cut portion of the strip-shaped metal sheet was determined as shown in Table 3, and 100 first electrode plates were prototyped. 1
Using 100 first electrode plates, 100 electrode groups were prototyped. A group of 100 electrodes was selected without any displacement and inserted into an outer can to assemble a battery.

[0067]

[Table 3]

Table 4 shows the amount of warpage of the electrode plates, the amount of winding deviation, and the rate of occurrence of short-circuits in the battery fabricated as described above.

[0069]

[Table 4]

As is clear from this table, the battery of the present invention has a small amount of warpage of the electrode plate, and has a small winding deviation and an internal short circuit.

Further, the shape of the cut portion was changed from a triangle to a circle, and a battery of the following example was manufactured as a trial. The batteries of the following examples were prototyped in the same manner as the batteries of the above-described examples except that the shape of the cut portion was changed.

[Examples 11 and 12] In the batteries of Examples 11 and 12, the cut portions of the strip-shaped metal sheet were circular as shown in FIG. 9 and the cut portions had different depths. The depth of the cut portion of the strip-shaped metal sheet used in the batteries of Examples 11 and 12 was determined as shown in Table 5. The radius of the circle was 1 mm. The interval between the cut portions was 30 mm.

The depth of the cut portion of the strip-shaped metal sheet was determined as shown in Table 5, and 100 first electrode plates were prototyped. 1
Using 100 first electrode plates, 100 electrode groups were prototyped. A group of 100 electrodes was selected without any displacement and inserted into an outer can to assemble a battery.

[0074]

[Table 5]

Table 6 shows the amount of warpage of the electrode plates, the deviation in winding, and the rate of occurrence of short-circuits in the battery fabricated as described above.

[0076]

[Table 6]

As is clear from this table, the battery of the present invention has a small amount of warpage of the electrode plate, and has a small winding deviation and an internal short circuit.

Further, the shape of the cut portion was changed to a triangle having different depths with the same opening width, and a battery of the following example was prototyped. The batteries of the following examples were prototyped in the same manner as the batteries of the above-described examples except that the shape of the cut portion was changed.

[Embodiments 13 and 14] In the batteries of Embodiments 13 and 14, the cut portions of the strip-shaped sheet metal were formed into a triangular shape as shown in FIG.
mm, and the depth of the vertex of the triangle was changed. The depth of the cut portion of the strip-shaped metal sheet used in the batteries of Examples 13 and 14 was determined as shown in Table 7. The interval between the triangular cut portions was 30 mm.

The depth of the cut part of the strip-shaped metal sheet was determined as shown in Table 7, and 100 first electrode plates were prototyped. 1
Using 100 first electrode plates, 100 electrode groups were prototyped. A group of 100 electrodes was selected without any displacement and inserted into an outer can to assemble a battery.

[0081]

[Table 7]

Table 8 shows the amount of warpage of the electrode plates, the occurrence of winding deviation, and the rate of occurrence of short-circuits in the battery manufactured as described above.

[0083]

[Table 8]

As is clear from the table, the battery of the present invention has a small amount of warpage of the electrode plate, and has a small winding shift and an internal short circuit.

Further, the shapes of the cut portions were made circular, and the intervals between the cut portions were changed, and the batteries of the following examples were prototyped.
The batteries of the following examples were prototyped in the same manner as the batteries of the above-described examples except that the cut portions were changed.

[Examples 15 to 20] In the batteries of Examples 15 to 20, the cut portion of the strip-shaped metal sheet was made circular as shown in FIG. 9, the depth of the cut portion was constant at 1 mm, and the cut portion was cut. Those with different intervals were used. The intervals between the cut portions of the strip-shaped metal sheet used in the batteries of Examples 15 to 20 were determined as shown in Table 9. However, the radius of the circle was 1 mm.

The intervals between cut portions of the strip-shaped metal sheet were determined as shown in Table 9, and 100 first electrode plates were prototyped. 1
Using 100 first electrode plates, 100 electrode groups were prototyped. A group of 100 electrodes was selected without any displacement and inserted into an outer can to assemble a battery.

[0088]

[Table 9]

Table 10 shows the amount of warpage of the electrode plates, the deviation in winding, and the rate of occurrence of short-circuits in the battery fabricated as described above.

[0090]

[Table 10]

As is clear from the table, the battery of the present invention has a small amount of warpage of the electrode plate, and has a small winding deviation and an internal short circuit. This table also shows that when the total length of the opening width of the cut portion exceeds 10% with respect to the entire length of the strip-shaped metal sheet, the discharge voltage when discharging at 30 A decreases.
For this reason, in order to improve high rate discharge at large current,
The total length of the opening of the cut part is one of the total length of the strip-shaped metal sheet.
It is desirable to make it less than 0%.

Further, the shape of the cut portion was made circular, and the radius of the circle as the cut portion was changed, to thereby experimentally manufacture batteries of the following examples. The batteries of the following examples were prototyped in the same manner as the batteries of the above-described examples, except that the radius of the circle as the cut portion was changed.

[Examples 21 to 28] In the batteries of Examples 21 to 28, the cut portion of the strip-shaped metal sheet was made circular as shown in FIG. 9, the depth of the cut portion was constant at 1 mm, and the radius of the circle was Used different ones. Table 11 shows the radius of the circle that is the cut portion of the strip-shaped metal sheet used in the batteries of Examples 21 to 28.
It was decided as follows. However, the depth of the cut portion was constant at 1 mm. The interval between the cut portions was 30 mm.

The intervals between the cut portions of the strip-shaped metal sheet were determined as shown in Table 11, and 100 first electrode plates were prototyped.
Using 100 first electrode plates, 100 electrode groups were prototyped. A group of 100 electrodes was selected without any displacement and inserted into an outer can to assemble a battery.

[0095]

[Table 11]

Table 12 shows the amount of warpage of the electrode plates, the occurrence of winding deviation, and the rate of occurrence of short-circuits in the battery manufactured as described above.

[0097]

[Table 12]

As is clear from the table, the battery of the present invention has a small amount of warpage of the electrode plate, and has a small winding deviation and an internal short circuit. This table also shows that when the total length of the opening width of the cut portion exceeds 10% with respect to the entire length of the strip-shaped metal sheet, the discharge voltage when discharging at 30 A decreases.
For this reason, in order to improve high rate discharge at large current,
The total length of the opening of the cut part is one of the total length of the strip-shaped metal sheet.
It is desirable to make it less than 0%.

In the above embodiment, a strip-shaped metal thin plate provided with a cut portion was welded to the exposed portion of the electrode plate to produce an electrode plate with less warpage. However, in the battery of the present invention, after welding the strip-shaped metal sheet provided with the cut portion to the exposed portion of the substrate of the electrode plate, the welding edge of the strip-shaped metal sheet is cut, so that it is not inferior to the above-described embodiment. In addition, an electrode plate with less warpage can be manufactured. By cutting off the portion of the strip-shaped metal sheet provided with the cut portion, the opening width of the cut portion can be reduced to 0, so that the high-rate discharge characteristics at a large current can be improved. By the way, in the battery prototyped by this method, the voltage when discharged at 30 A was as high as 1.039 V, and the amount of warpage of the electrode plate was only 0.01 mm.

Further, in the battery of the present invention, after a strip-shaped metal sheet having no cut portion is welded to the exposed portion of the substrate of the electrode plate, a cut portion is provided so as to cut off the welding edge of the strip-shaped metal sheet. It is also possible to manufacture an electrode plate having a small warp so as not to be inferior to an electrode plate manufactured by welding a strip-shaped metal sheet having a cut portion to an exposed portion of the substrate.

[0101]

The battery of the present invention has the features that the warpage of the electrode plate obtained by welding the strip-shaped metal sheet to the exposed portion of the substrate can be reduced, and the internal short circuit can be minimized when the battery is actually assembled. That is, the battery of the present invention
On the exposed portion of the substrate of the electrode plate, a band-shaped metal sheet provided with a plurality of cut portions at predetermined intervals is welded, and the band-shaped metal sheet is welded to the current collector, and further, the band-shaped metal sheet is This is because the welding edge to be welded to the current collector plate is cut off at the cut portion, and the active material-filled side edge opposite to the welding edge is made continuous. In the strip-shaped metal sheet having this structure, the welding edge welded to the current collector is cut off at the cutting portion, so that warpage of the electrode plate in which the strip-shaped metal sheet is welded to the substrate exposed portion can be reduced. For this reason, there is a feature that a uniform product can be manufactured by aligning the end faces of the stacked electrode groups in a plane. Furthermore, since the strip-shaped metal sheet with this structure has the active material-filled side edge opposite to the weld edge continuous, the occurrence of internal short-circuits in this part is minimized, and mass production of excellent batteries is achieved. The possible features are realized.

Furthermore, the method for manufacturing a battery according to the seventh aspect of the present invention is characterized in that, in addition to being able to reduce the warpage of the electrode plate, it is possible to minimize internal short-circuits and prevent a decrease in discharge characteristics. . This is because the manufacturing method cuts a welding edge to be welded to the current collector plate at a predetermined interval on a substrate exposed portion of the substrate at a predetermined interval, and connects the active material filled side edge opposite to the welding edge to the predetermined edge. This is because an electrode plate is manufactured by welding a strip-shaped metal sheet provided with a plurality of cut portions at the intervals described above, and the strip-shaped metal sheet is cut at a predetermined width along the welding edge. In this manner, the electrode plates obtained by cutting the strip-shaped thin metal plates welded to the exposed portions of the substrate along the welding edges can make the end faces of the electrode group more accurate and flat in a stacked state. Therefore, it can be welded to the current collector in a larger area,
There is a feature that high-rate discharge characteristics at a large current can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a state in which a current collector is connected to an electrode plate of an electrode group incorporated in a battery.

FIG. 2 is a plan view showing an electrode plate in which a belt-shaped thin metal plate is welded and warped.

FIG. 3 is a plan view of a strip-shaped metal sheet having a cut portion of a conventional battery.

FIG. 4 is a partial cross-sectional front view of a battery according to an embodiment of the present invention.

5 is an exploded view of the electrode plate of the battery shown in FIG.

6 is an enlarged cross-sectional view showing a laminated structure of an electrode group of the battery shown in FIG.

FIG. 7 is a plan view showing a state in which a cut portion is provided in a strip-shaped metal sheet.

8 is a plan view showing a state in which the strip-shaped thin metal plate shown in FIG. 7 is welded to an exposed portion of the substrate.

FIG. 9 is a plan view showing another example of a strip-shaped metal sheet provided with a cut portion.

FIG. 10 is a plan view showing another example of a strip-shaped metal sheet provided with a cut portion.

FIG. 11 is a plan view showing another example of a strip-shaped metal sheet provided with a cut portion.

FIG. 12 is a plan view showing another example of a strip-shaped metal sheet provided with a cut portion.

FIG. 13 is a perspective view showing an example of a method for manufacturing an electrode plate.

FIG. 14 is a perspective view showing another example of the method for manufacturing an electrode plate.

15 is a development view of a current collector of the battery shown in FIG.

16 is an enlarged sectional view of the current collector shown in FIG.

FIG. 17 is a plan view showing an example of a step of providing a substrate exposed portion on an electrode plate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 1st electrode plate 2 ... 2nd electrode plate 3 ... Separator 4 ... Electrode group 5 ... Outer can 6 ... Current collector plate 6A ... Lead plate 6B
... Central hole 6C ... Slit 6D ... Through hole 6E ... Protrusion 7 ... Substrate exposed part 8 ... Active material filling part 9 ... Substrate 10 ... Strip-shaped thin metal plate 10A ... Welding edge 10
B: active material-filled side edge 11: sealing plate 12: terminal 13: protective tape 14: cut section

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takeshi Yoshida 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Yuji Goto 2-chome, Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Hiroyuki Tagawa 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 5H016 AA06 BB00 BB04 BB08 EE01 HH01 HH13 5H017 AA02 BB00 BB11 BB14 CC03 DD03 EE01 HH03 5H022 AA04 BB01 BB02 BB11 CC12 CC16 EE01 5H028 AA05 BB00 BB03 BB05 CC05 CC12 EE01 HH01 HH05

Claims (10)

[Claims] A first electrode plate (1) comprising a positive electrode plate and a negative electrode plate
And a second electrode plate (2) laminated via a separator (3)
(4), an outer can (5) accommodating the electrode group (4), and the first electrode plate (1). The first electrode plate (1) is electrically connected to one terminal. The first electrode plate (1) is a non-sintered electrode in which an active material is filled in a metal three-dimensional porous substrate (9), and the substrate ( 9) has a substrate exposed portion (7) that is exposed, a band-shaped metal sheet (10) is welded to the substrate exposed portion (7), and the band-shaped metal sheet (10) is connected to the current collector plate (6). In a battery which is welded to a substrate, a strip-shaped thin metal plate (10) to be welded to a substrate exposed portion (7) is provided with a plurality of cut portions (14) at predetermined intervals.
4) separates the welding edge (10A) to be welded to the current collector plate (6) and provides the active material-filled side edge (10B) opposite to the welding edge (10A) in a continuous state. A battery comprising: 2. The cutting portion (14) is linear, circular, oval,
2. The battery according to claim 1, wherein the battery is one of a chicken egg and a triangle. 3. The cutting portion (14) has a depth of a band-shaped metal sheet (10).
The battery according to claim 1, wherein the battery has a width of 30% or more and less than 100% of a total width of the battery. 4. The battery according to claim 1, wherein an interval between adjacent cut portions (14) is 50 mm or less. 5. The battery according to claim 1, wherein the total length of the opening width of the cut portion (14) at the welding edge (10A) is less than 10% of the entire length of the strip-shaped metal sheet (10). 6. A welding edge (10A) to be welded to a current collector plate (6) is provided at a predetermined interval on a substrate exposed portion (7) of a substrate (9) which is a metal three-dimensional porous body filled with an active material. At the welding edge (10
A) a strip-shaped metal sheet provided with a plurality of cut portions (14) at predetermined intervals so as to connect the active material filled side edges (10B) on the opposite side of (A).
A welding process for manufacturing an electrode plate by welding (10), and a separator on the first electrode plate (1) on which the strip-shaped thin metal plate (10) is welded.
A laminating step of laminating the second electrode plate (2) through (3) to produce an electrode group (4); and a strip-shaped metal sheet (10) provided on the first electrode plate (1) of the electrode group (4). ), A step of welding the current collector plate (6) to the current collector plate, a step of inserting the electrode group (4) formed by welding the current collector plate (6) into the outer can (5), and injecting the outer can (5). And a step of closing the opening of the outer can (5). 7. A welding edge (10A) welded to a current collector plate (6) is provided at a predetermined interval on a substrate exposed portion (7) of a substrate (9) which is a metal three-dimensional porous body filled with an active material. At the welding edge (10
A) a strip-shaped metal sheet provided with a plurality of cut portions (14) at predetermined intervals so as to connect the active material filled side edges (10B) on the opposite side of (A).
A welding step of welding the (10) to produce an electrode plate; a cutting step of cutting the strip-shaped metal sheet (10) at a predetermined width along the welding edge (10A); and cutting the strip-shaped metal sheet (10). Separator on the first electrode plate (1)
A laminating step of laminating the second electrode plate (2) through (3) to produce an electrode group (4); and a strip-shaped metal sheet (10) provided on the first electrode plate (1) of the electrode group (4). ), A step of welding the current collector plate (6) to the current collector plate, a step of inserting the electrode group (4) formed by welding the current collector plate (6) into the outer can (5), and injecting the outer can (5). And a step of closing the opening of the outer can (5). 8. The method for manufacturing a battery according to claim 7, wherein in the cutting step, the band-shaped thin metal plate (10) is cut to a width at which the cut portion (14) is removed. 9. A substrate (9) made of a metal three-dimensional porous material filled with an active material and provided with an exposed portion (7).
(7) a welding step of manufacturing a first electrode plate (1) by welding a strip-shaped metal sheet (10); and a welding edge (10A) of the strip-shaped metal sheet (10). ), A cutting step of providing a plurality of cutting portions (14) at predetermined intervals in a state where the active material-filled side edge (10B) on the opposite side is continuous, and a first electrode plate (10) obtained by cutting the strip-shaped metal sheet (10). 1) Separator
A laminating step of laminating the second electrode plate (2) through (3) to produce an electrode group (4); and a strip-shaped metal sheet (10) provided on the first electrode plate (1) of the electrode group (4). ), A step of welding the current collector plate (6) to the current collector plate, a step of inserting the electrode group (4) formed by welding the current collector plate (6) into the outer can (5), and injecting the outer can (5). And a step of closing the opening of the outer can (5). 10. The cutting section (14) of the strip-shaped sheet metal (10) is selected from the group consisting of a straight line, a circle, an ellipse, a chicken egg, and a triangle. Battery manufacturing method.