JPH1079254A - Rectangular battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rectangular battery which involves no risk that mixture is exfoliated in the folded part (s) of an electrode or around there and can lessen the quantity of mixture in use. SOLUTION: This rectangular battery includes a positive electrode plate 108 formed by applying a mixture containing a positive electrode active material to a sheet-form current collecting member 112, negative electrode plates formed by applying a mixture containing a negative electrode active material to sheet- form current collecting member 112, and separators 115, in such an arrangement that the positive electrode plates 108 and negative electrode plates are put one over another opposingly with the separators 115 interposed, wherein at least either of the positive and negative electrode plates is structured so that current collecting member 112 constituting one of the electrode plates is folded one or more times, and the mixture 110 is not applied substantially to the folded part (s) of the current collecting member 112.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a prismatic battery such as a lithium secondary battery.

[0002]

2. Description of the Related Art Conventionally, as a prismatic battery, one of a positive electrode and a negative electrode is formed in a bellows shape, and the other square electrode is inserted one by one into a concave portion of the bellows-shaped electrode and compressed. One having a laminated structure of the formed positive electrode and negative electrode is known. In this method of manufacturing a prismatic battery, first, as one of the positive electrode plate and the negative electrode plate, the mixture is applied to the entire surface of the belt-shaped current collector, and formed by the required number of sheets. The thing connected in the shape of a sheet is prepared, and it is packed in a separator that can be separated and insulated from other electrode plates. It is folded at predetermined intervals to form a bellows. After inserting another electrode plate one by one into the folded portion of the bellows-shaped electrode, the electrode plates are alternately opposed to each other and overlapped. This is compressed to form a laminated electrode. At this time, since the leads of the electrode plate on the inserted side are independent of each other, these are bundled and joined to make one lead.

Also, as disclosed in US Pat. No. 5,147,737, in the conventional prismatic battery, a mixture containing an active material is provided on the outermost surfaces on both sides in the direction in which the bellows expands and contracts. Some square batteries are not coated. The outermost surfaces on both sides in the direction in which the bellows expand and contract cannot be paired with the positive electrode and the negative electrode via the separator. By not applying a mixture to this surface, the battery capacity per battery volume is increased. Can be done.

[0004]

SUMMARY OF THE INVENTION In a conventional prismatic battery,
The bent portion of the bellows-shaped electrode or the vicinity thereof may have the possibility that the mixture may come off from the current collector due to bending stress or the like. Peeling of the mixture may lead to a decrease in battery performance (capacity), and the peeled mixture may penetrate the separator and be shortened. If such a short circuit occurs in a battery having a closed structure, decomposition or evaporation of the electrolyte occurs due to an increase in the temperature inside the battery, which may cause an increase in internal pressure due to a large amount of generated gas, which may hinder battery performance.

[0005] In the conventional prismatic battery, on the inner surface of the bent portion, the coated portion of the mixture containing the positive electrode active material and the coated portion of the mixture containing the negative electrode active material are in close contact via a separator. In addition, there is no electrode paired with the mixture applied outside the bent portion on the outer surface of the bent portion. Therefore, the mixture applied to the bent portion hardly contributed to the electrode reaction.

Further, each of the electrode plates to be inserted has one
Since the sheets are separated one by one, a step of joining and unifying leads is required after pressing and laminating the electrode plates. This process has a problem that the productivity is lowered and the quality (welding) of a large number of lead bundles is not stable. The present invention has been made in view of the above-described circumstances, and is a prismatic battery that does not cause a decrease in battery performance without peeling of a mixture at a bent portion of an electrode or in the vicinity thereof, and a conventional square battery. An object of the present invention is to provide a prismatic battery that can reduce the amount of mixture used while maintaining battery performance.

[0007]

Means for Solving the Problems In the conventional bellows electrode type prismatic battery, the present inventor did not apply a mixture to the bent portion of the electrode plate having a bellows shape, but alternately through a separator. By forming an electrode having a laminated structure by facing each other, the mixture does not peel off at the bent portion of the electrode or in the vicinity thereof, and the mixture is formed without lowering the battery performance. Have been found to be able to reduce the amount used, and have led to the present invention.

That is, the prismatic battery of the present invention comprises a positive electrode plate in which a mixture containing a positive electrode active material is applied to a sheet-like current collector, and a sheet-like current collector containing a negative electrode active material. A prismatic battery comprising: a negative electrode plate coated on a substrate; and a separator, wherein the positive electrode plate and the negative electrode plate are alternately opposed to each other with the separator interposed therebetween. And at least one electrode plate of the negative electrode plate, the current collector forming the one electrode plate is folded at least once, and the mixture is formed in a bent portion of the current collector. It is characterized in that it is not substantially applied.

In the prismatic battery of the present invention, since the mixture is not applied to the bent portion, the mixture does not peel off at or near the bent portion.
In addition, it is possible to save the mixture in the bent portion which has not contributed to the electrode reaction in the conventional prismatic battery.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the prismatic battery of the present invention, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide or the like can be used as a mixture containing a positive electrode active material, and is made of aluminum foil or the like. It is applied to both sides of the current collector. Carbon or the like can be used as a mixture containing the negative electrode active material, and is applied to both surfaces of a current collector made of a copper foil or the like. As the separator, a separator made of polyethylene, polypropylene, or the like can be used.

[0011] In the prismatic battery of the present invention, the shape of the bent portion of the current collector is not particularly limited, and the current collector may be folded at an acute angle or may be folded in a U-shape. The current collector has at least one bent portion, and the number of electrode plates can be selected as needed.
The positive electrode plate and the negative electrode plate are housed in a square case made of metal in a state of being immersed in an electrolytic solution in a form of being alternately opposed to each other with a separator interposed therebetween. The electrolytic solution used at this time is not particularly limited, and LiPF ₆ or the like can be used as a solute.

In the prismatic battery of the present invention, it is desirable that the current collector has a bellows shape that is alternately folded, and that the bent portion is substantially not coated with the mixture. Thus, only one lead needs to be attached to the electrode. At this time, the current collector has a through hole in a folded portion, and the electrode plate having the current collector is sandwiched by the separator from both sides and sandwiched from both surfaces of the electrode plate through the through hole. It is desirable that the separator be integrally joined. Thereby, at the time of folding, displacement of the separator can be prevented.

Further, it is preferable that both the positive electrode plate and the negative electrode plate have a bellows shape in which the current collectors are alternately folded. As a result, both electrodes require only one lead to be attached to the electrode. At this time,
The current collector of one of the positive electrode plate and the negative electrode plate has a bellows shape alternately folded in the horizontal direction, and the other current collector has a bellows shape alternately folded in the vertical direction. It is preferable that the electrode plate and the other electrode plate are stacked so that the one electrode is folded in the horizontal direction and the other electrode is folded in the vertical direction, and the two electrodes are alternately stacked. As a result, the bellows-like electrodes can be stacked with high density and high efficiency, and the productivity of the prismatic battery is improved.

[0014] Alternatively, the current collector is a portion of a rectangular flat plate bent at a bent portion in the form of irregularities that are continuous in the horizontal direction, and then in the upward, lateral, and downward directions, and further in the horizontal direction. It is desirable that the flat plate is folded and further folded alternately in the lateral direction. This makes it possible to improve the productivity in the electrode pressing step and eliminate the lead connection step.

[0015] Alternatively, one of the positive electrode plate and the negative electrode plate has a bellows-shaped current collector,
The other electrode plate desirably has a bi-fold current collector. This facilitates formation of a laminated structure of both electrode plates. Preferably, one of the positive electrode plate and the negative electrode plate has a bellows-shaped current collector, and the other electrode plate has a plurality of independent rectangular current collectors. This makes it easier to form a laminated structure of the two electrode plates.

Further, it is preferable that each of the positive electrode plate and the negative electrode plate has a bi-folded current collector. This facilitates formation of both electrodes, and facilitates formation of both electrode plates. The prismatic battery of the present invention can be manufactured as follows. First, a mixture containing the active material is applied in a rectangular shape at predetermined intervals on both sides of the belt-shaped current collector, and the mixture is thoroughly dried, and the mixture-applied portion and the mixture-unapplied portion alternate. To form a band-shaped mixture-applying plate before bending. The portion where the mixture is applied corresponds to the electrode plate, and the portion where the mixture is not applied corresponds to the portion to be bent. At this time, after application of the mixture, the mixture can be formed into a predetermined shape and a predetermined size by pressing or cutting as necessary.

Further, in the band-shaped mixture-applied plate before bending, a larger band-shaped current collector having at least the width of the band of the mixture-applied plate is prepared, and the mixture containing the active material is collected. It is also possible to form an object having a predetermined shape and a predetermined size by applying a stripe on both surfaces of the electric body and pressing or cutting in a direction perpendicular to the stripe. At this time, the width of the stripe-applied portion is a width corresponding to the width or the vertical width of the electrode plate, and the width of the non-applied portion is a width necessary for a portion where the current collector is bent.

As for the lead connecting the electrode and the terminal, one lead of a predetermined shape is prepared, and it is formed by welding to the end of the band-shaped mixture application plate before bending, where the mixture is not applied. be able to. Alternatively, when the mixture is applied to the current collector, a current collector having a size capable of forming a lead in addition to a part to be an electrode plate and a part to be bent is prepared in advance, and then pressed or cut, It can also be formed simultaneously with the formation of the band-shaped mixture application plate before bending.

The through-hole for fusing the separator provided at the bent portion of the current collector is formed by pressing or the like at the same time as the formation of the band-shaped mixture coating plate before bending, or the band-shaped mixture before bending. It can be formed after forming the coating plate. Insert one of the unfolded band-shaped mixture application plates provided with leads into the folded separator, and use ultrasonic waves around the perimeter of the unfolded band-shaped mixture application plate other than the leads and through holes. Fused and bagged in separator.

The band-shaped mixture-applied plate before folding, packed in the separator, and the band-shaped mixture-applied plate before folding, which are not packed in the separator, are alternately folded at the uncoated portion. Bending is performed while changing the direction to form a bellows-like bent bellows as a whole, and two kinds of bellows-like electrodes for a positive electrode and a negative electrode are formed. Using these two types of bellows-like electrodes for the positive electrode and the negative electrode, one of the bellows-like electrodes is alternately folded in the vertical direction and the other bellows-like electrode is alternately folded in the horizontal direction, and the respective electrode plates are overlapped. Two types of bellows-shaped electrodes are combined.

In a state in which the two types of electrodes are combined, a rectangular battery in which the positive electrode plate and the negative electrode plate are alternately opposed to each other with a separator interposed therebetween and compressed from both sides in the direction in which the bellows expands and contracts. Can be made. In addition, an electrode having a bellows-shaped current collector and a strip of a rectangular flat plate bent in a horizontal direction, and then in an upward direction, a horizontal direction, a downward direction, and a laterally continuous uneven shape in the vertical direction. A prismatic battery composed of an electrode having a current collector in which a continuous rectangular flat plate is folded and further alternately folded in the lateral direction is formed by folding the former electrode into a continuous rectangular flat plate in the vertical direction of the latter electrode. By compressing from both sides in the direction in which the bellows expands and contracts in this state, the positive electrode plate and the negative electrode plate are alternately opposed to each other with a separator interposed therebetween. Thus, a prismatic battery can be manufactured.

At this time, the former method of forming the electrodes can employ the above-described method of forming the bellows-like electrodes. In the formation of the latter electrode, first, a mixture is applied to the current collector to form two rectangular application portions of a predetermined size arranged in the lateral direction on the current collector. A set of these two coated portions is applied, and a predetermined number of coated portions are provided at predetermined intervals by non-coated portions. The width of the portion where the mixture is not applied between the two squares is the width required for the bent portion, and the width of the portion where the mixture is not applied between the sets is a width corresponding to the width of the electrode plate.

This is press-cut or cut to form a strip-shaped mixture-applied plate having irregularities that are continuous in the horizontal direction, then in the upward, horizontal, and downward directions, and further in the horizontal direction at the bent portion of the rectangular flat plate. Can be formed. Fold it in two at the uncoated part of the mixture between the two squares of the set,
In addition, the current collector is formed by applying a bending gauze so that it becomes a bellows shape at the part where the mixture is not applied and the mixture is slightly applied from the boundary between the mixture application part and the electrode plate.
It is assumed that a rectangular flat plate that is continuous in the vertical direction is folded and further alternately folded in the horizontal direction.

Alternatively, a bellows-like electrode serving as a positive electrode or a negative electrode and an electrode having a plurality of folded current collectors serving as the other electrode are prepared. The concave portions of the two-fold electrode are superimposed on the respective convex portions of the bellows-shaped electrode, and are compressed from both sides in the direction in which the bellows expands and contracts in a state where the bellows-shaped electrode and the two-folded electrode are combined. According to this method, a prismatic battery in which a positive electrode plate and a negative electrode plate are alternately opposed to each other with a separator interposed therebetween can be manufactured.

Alternatively, the above-mentioned bellows-like electrode serving as a positive electrode or a negative electrode and an electrode having a plurality of independent rectangular current collectors serving as the other electrode are prepared. An electrode having a plurality of independent square current collectors is inserted into each concave portion of the bellows-shaped electrode, and the bellows-shaped electrode is combined with an electrode having a plurality of independent square current collectors. Compress from both sides in the direction of expansion and contraction. According to this method, a prismatic battery in which a positive electrode plate and a negative electrode plate are alternately opposed to each other with a separator interposed therebetween can be manufactured.

Alternatively, a positive electrode and a negative electrode having a plurality of folded current collectors are prepared. A positive electrode and a negative electrode having a folded current collector are combined so that the positive electrode plate and the negative electrode plate alternately overlap. By combining a plurality of combinations of the positive electrode and the negative electrode, a prismatic battery in which a positive electrode plate and a negative electrode plate are alternately opposed to each other with a separator interposed therebetween can be manufactured.

[0027]

According to the prismatic battery of the present invention, since the mixture in the bent portion and the vicinity thereof does not peel off, it is possible to prevent a decrease in battery performance and a short circuit. Further, since the mixture in the bent portion which has not contributed to the electrode reaction in the conventional prismatic battery can be saved, the amount of the mixture can be reduced while maintaining the battery performance.

The bellows-like electrode or the rectangular flat plate is bent in the horizontal direction, then in the upward direction, in the horizontal direction,
A single lead is formed by using an electrode with a current collector that is folded in a rectangular flat plate that is continuous downward and upward and downward, and that is continuous in the vertical direction, and that is alternately folded in the horizontal direction. This eliminates the need for a step of joining and unifying leads after pressing and lamination.

[0029]

The present invention will be described below in detail with reference to examples. Embodiment 1 In the prismatic battery of this embodiment, as shown in FIG. 1, the electrode 102 has a laminated structure in which a mixture 102 containing a positive electrode active material has a bent portion 106 of a bellows-shaped current collector 104. Positive electrode plate 1 consisting of a coating portion formed by coating on both sides except for
08 and a negative electrode plate 114 composed of an applied portion formed by applying a mixture 110 containing a negative electrode active material to both surfaces except for a bent portion of a bellows-shaped current collector 112, with a separator 115 interposed therebetween. Are superimposed on each other.

In this embodiment, the mixture 10 containing the positive electrode active material is used.
A mixture composed of lithium manganese oxide and a binder was used as 2, and a mixture composed of carbon and a binder was used as the mixture 110 containing the negative electrode active material. Aluminum foil was used as the current collector 104 for the positive electrode, and copper foil was used as the current collector 112 for the negative electrode. In the manufacture of the prismatic battery of the present embodiment, first, as shown in FIG.
A current collector 116 having a band shape of about 0.02 mm, a mixture 118 composed of a lithium manganese oxide and a binder, and a mixture application capable of applying the mixture 118 on the surface of the current collector 116 in a planar and intermittent manner. The current collector 116 is divided into two surfaces 120 by using the mixture 120 and the front surface 122 and the back surface 12.
4, the front face 122 and the back face 1 of the current collector 100
24 at the same position, 30-60 mm wide, 30-40 m long
The mixture 118 was applied while forming m-shaped rectangular mixture application portions 126 at regular intervals of 1 to 2 mm. Note that the coating thickness was 0.05 to 0.2 mm.

Subsequently, the mixture-applied portion 126 is left while leaving the mixture-unapplied portion 128 between the rectangular mixture-applied portions 126 and a portion of the lateral end portion 129 of the current collector 116. As shown in FIG. 3 and FIG. 4, press-cut or cut, and as shown in FIG. 3 and FIG.
8 (hereinafter, referred to as an uncoated portion for bending) 134 and a lead 1 formed of a part of the lateral end portion 129 of the current collector 116.
35 (size; width 2 to 3 mm, length 10 to 30 mm, thickness 0.1 to 0.2 mm), a band-shaped mixture-applied plate 136 for a positive electrode, which was formed before bending, was formed. In addition,
The uncoated portion 134 for bending of the mixture application plate 136 has a through hole 13 for welding a separator having a size of about φ2.
7 was formed at the same time as pressing.

The mixture applying plate 13 for the positive electrode before bending
6 is divided into two parts as shown in FIG.
40 around the mixture application plate other than the lead 135
42 and the portion 14 where the separator of the through hole 136 overlaps
4 are welded to each other using ultrasonic waves,
In a bag. The band-shaped mixture applying plate 136 for the positive electrode, which is packed in the separator 140 before folding, is folded at both the folding non-application portions 134 while alternately changing the folding direction, and the mixture is formed into a bellows shape as a whole. The non-applied portion was folded to form a bellows-like electrode 146 for the positive electrode shown in FIG. FIG. 6 shows a state in which the electrode packed in the separator 140 is bent by seeing through the separator 140.

As shown in FIG. 7 and FIG. 8, in the same manner as the formation of the band-shaped mixture application plate 136 for the positive electrode before bending, it is made of copper foil and has a thickness of 0.01 to 0.02 mm. A current collector, a mixture of carbon and a binder, a coated portion 148 of a rectangular mixture having a width of 30 to 40 mm and a length of 30 to 60 mm, and a bending portion having a constant width of 1 to 2 mm. An unfolded band-shaped mixture applying plate 15 for a negative electrode composed of an application portion 150 and a lead 151
2 was formed. The coating thickness is 0.05 to 0.2 mm
And

The negative electrode mixture application plate 152 is bent while alternately changing the folding direction at the folding non-coating portion 150, and the folding non-coating portion 150 is folded so as to form a bellows shape as a whole, and a negative electrode is formed. A bellows-like electrode 154 was formed. These bellows-like electrodes 14 for the positive electrode
9 and the bellows-like electrode 154 for the negative electrode are positioned as shown in FIG. 9, and the bellows-like electrode 146 for the positive electrode is alternately folded in the horizontal direction and the bellows-like electrode 154 for the negative electrode is alternately folded in the vertical direction. Were combined.

The two bellows-shaped electrodes 146 and 154 are combined and compressed from both sides in the direction in which the bellows expands and contracts, and the positive electrode plate and the negative electrode plate are alternately opposed to each other with a separator interposed therebetween. A prismatic battery was produced. (Embodiment 2) The prismatic battery of the present embodiment is the same as the prismatic battery of Embodiment 1, but the band-shaped mixture coating plate 13 for the positive electrode and the negative electrode formed in Example 1 before bending.
6, 152 are different from each other.

First, as shown in FIG. 10, a band-shaped mixture-applied plate for a positive electrode before bending is made of aluminum foil and has a width of 500 to 1000 mm and a thickness of 0.01 to 1000 mm.
Using a 0.02 mm current collector 200, a mixture 202 composed of a lithium manganese oxide and a binder, and a mixture application tool 204 capable of applying the mixture 202 in a stripe shape on the surface of the current collector 200 , Front side 206 and back side 2
08, the mixture 202 was applied to the stripe at the same position.
The mixture-applied portion 210 having a width of 0 to 40 mm and the non-applied portion 212 having a width of about 1 mm between the mixture-applied portion 210 were formed. The coating thickness is 0.05 to
0.2 mm.

Subsequently, by pressing and cutting,
As shown in FIG. 11, a non-application portion for bending corresponding to a bent portion composed of an application portion 214 of the mixture, which is formed from the application portion 210 of the mixture and corresponds to the positive electrode plate, and a non-application portion 212 of the mixture. 216 and a lead 218 (size; width 2) consisting of a part of the lateral end portion 217 of the current collector 200
~ 3mm, length 10 ~ 30mm, thickness 0.1 ~ 0.2m
m) to form a band-shaped mixture-applied plate 220 for a positive electrode before bending composed of: In addition, in the uncoated portion 216 for bending, a through hole 222 for fusing the separator having a size of about φ2 was formed at the same time as pressing.

The band-shaped mixture-applied plate for the negative electrode before bending is made of copper foil and has a thickness of 0.1 mm in the same manner as the formation of the band-shaped mixture-applied plate 220 for the positive electrode before bending.
It consists of a current collector of 01 to 0.02 mm and a mixture of carbon and a binder, and has a width of 30 to 40 mm and a length of 30
部分 60mm square mixture application part and 30-40mm
A non-folded band-shaped mixture-applied plate for a negative electrode, comprising a non-folded portion having a constant lateral width and a lead, was formed. The lead of this mixture-coated plate was formed by bending 90 ° in the short side direction of the mixture-coated plate.

Using the mixture application plate 220 for the positive electrode, the mixture application plate for the negative electrode, and the separator, the positive electrode plate and the negative electrode plate alternately face each other via the separator in the same manner as in Example 1. A stacked square battery was produced. (Embodiment 3) In the prismatic battery according to the present embodiment, the current collector is formed in a band shape with concavities and convexities that are continuous in the horizontal direction, then in the upward direction, the horizontal direction, the downward direction, and further in the horizontal direction at the bent portion of the rectangular plate. Yes,
A rectangular flat plate that is continuous in the vertical direction is folded, and is alternately folded in the horizontal direction.

In the manufacture of the prismatic battery according to the present embodiment, the bellows-like electrode 3 for the positive electrode was used in the same manner as in the first embodiment.
00 was formed. As shown in FIGS. 12 and 13, the negative electrode plate is made of aluminum foil and has a width of 1 mm.
A current collector 302 having a thickness of 00 to 200 mm and a thickness of 0.01 to 0.02 mm; a mixture 304 including lithium manganese oxide and a binder; and a mixture 304 on the surface of the current collector 302.
A mixture application tool 306 that can apply the product in a planar and intermittent manner;
Is applied to the current collector 302 at the same position on the front surface 308 and the rear surface 310 of the current collector 302 by applying a rectangular mixture application portion 312 having a width of 30 to 40 mm and a length of 30 to 60 mm. In the direction, two coatings are applied side by side at a distance of 1 to 2 mm (the non-applied portion 313 of the mixture shown in FIG. 13). The mixture 304 was applied onto the current collector 302 at the portion 314) where the agent was not applied. The coating thickness is 0.05 to 0.2
mm.

As shown in FIG. 14, as shown in FIG. 14, by pressing, a rectangular mixture-applied portion 316 composed of a mixture-applied portion 312 and corresponding to the positive electrode plate,
13, a non-coated portion 318 corresponding to the bent portion, a non-coated portion 314 of the mixture, and a non-coated portion 320 of a 30 to 40 mm square and 30 to 60 mm square non-coated portion of the mixture; The side end portion 321 of the body 302 (FIG. 1)
3), a width of 2-3 mm and a length of 10
A mixture application plate 324 composed of a lead 316 having a size of 30 mm was formed.

As shown in FIG. 15, the mixture application plate 324 is folded into two at a bending non-application portion 318, and further, a boundary between the mixture application portion 316 and the mixture non-application portion 320 is formed. At a position 1 to 2 mm from the portions 326 and 326 on the side of the non-applied portion 320 of the mixture, it was folded while alternately changing the folding direction. In this way, the rectangular flat plate is folded in the horizontal direction, then upwards, laterally, downwards, and furthermore, it is a strip of unevenness that is continuous with the horizontal direction, and the rectangular flat plate that is continuous in the vertical direction is folded, and further horizontally A negative electrode 328 having a current collector alternately folded was formed.

Further, as shown in FIG. 16, a bellows-like electrode 300 for a positive electrode packed in a bag-like separator is inserted into an electrode 328 for a negative electrode, and a rectangular Recess 33 formed by folding a flat plate
The bellows-shaped electrode 300 for the positive electrode was sandwiched between 0. This was compressed from both sides in the direction in which the bellows expands and contracts to form a prismatic battery in which positive and negative electrode plates are alternately opposed to each other with a separator interposed therebetween. (Embodiment 4) In the prismatic battery of this embodiment, the positive electrode plate has a bellows-shaped current collector, and the negative electrode plate has a folded current collector.

In the manufacture of the prismatic battery of the present embodiment, the bellows-like electrode 4 for the positive electrode was used for the positive electrode plate in the same manner as in the first embodiment.
00 was formed. As for the negative electrode plate, as shown in FIG. 17, a band-shaped current collector 402 made of copper foil and having a width of 100 to 200 mm and a thickness of 0.01 to 0.02 mm, and a mixture comprising carbon and a binder. 404 and the current collector 40
And a mixture applying tool 406 that can apply the mixture 404 in a planar manner and intermittently on the surface of the second surface 2 and use the mixture applying tool 406 to place the current collector 402 at the same position on the front surface 408 and the back surface 410. In addition, the applied portion 412 of a rectangular mixture having a width of 30 to 40 mm and a length of 30 to 60 mm is
m (the uncoated portion 41 of the mixture shown in FIG. 17)
In 3), coating was performed so as to be arranged in two in the vertical direction, and this was coated as one set. The coating thickness is 0.05 to 0.2 m
m.

Subsequently, as shown in FIG. 18, by press punching, as shown in FIG. 18, a mixture application portion 415 (size; 30 to 40 m in width) formed from the mixture application portion 412 and corresponding to the positive electrode plate
m, 30 to 60 mm in length), a non-folded portion 416 corresponding to the portion to be bent, and a part of the lateral end portion 417 (shown in FIG. 17) of the current collector 402, which is closer to the non-folded portion 416. 418 (size; width 2-3 mm, length 10-30 mm)
And a sheet-shaped mixture application plate 42 for a negative electrode composed of
0 was formed.

As shown in FIG. 19, the mixture application portion 412, which is composed of the mixture application portion 412 and corresponds to the positive electrode plate, is provided.
2 (size: 30 to 40 mm in width, 30 to 60 mm in length), a non-application portion for bending 424 corresponding to a bent portion formed of a non-application portion of the mixture, and a current collector 402
Part of the lateral end portion 417 of the uncoated part 4
A negative electrode sheet-shaped mixture application plate 428 composed of a lead 426 having the same size as the lead 418 formed at a position distant from 24 was formed.

The mixture-coated body 42 of these sheets for the negative electrode
0, 428, the uncoated portion 416 for bending,
The sheet was bent at 424 to be folded in two to form two types of folded electrodes 430 and 432 for the negative electrode. A bellows-shaped electrode 400 for a positive electrode and two types of folded electrodes 430 for a negative electrode,
As shown in FIG. 20, a double-folded electrode 430 having a lead at one end and a double-folded electrode 430 on one side of the bellows-shaped electrode 400 for the positive electrode is used as shown in FIG.
With a bellows-shaped electrode 40 for a positive electrode packed in a bag in a separator.
The two convex electrodes 430 and 432 for the negative electrode were fitted together with the concave parts of the negative electrode 0 while fitting them together.

Compression was performed from both sides in the direction in which the bellows expands and contracts to form a prismatic battery in which positive and negative plates are alternately opposed to each other with a separator interposed therebetween. (Embodiment 5) The prismatic battery of this embodiment is the same as that of Embodiment 4, except that the method of forming the folded electrode 432 for the negative electrode is different.

In the manufacture of the prismatic battery of this embodiment, the first embodiment
A bellows-like electrode for the positive electrode was formed in the same manner as described above. In the production of the negative electrode plate, as shown in FIG.
Band-shaped current collector 502 having a thickness of 00 mm and a thickness of 0.01 to 0.02 mm, and a mixture 504 including carbon and a binder.
And a mixture application tool 506 that can apply the mixture 504 in two rows in parallel on the surface of the current collector 502 using a width of 30 to 4
The application portion 512 of the two rows of band-like mixture of 0 mm is 1 to 1 in width.
The mixture 504 is applied to the same position on the front surface 508 and the back surface 510 of the current collector 502 so as to be formed at a constant interval of 2 mm (the unapplied portion 513 of the mixture shown in FIG. 21). did. Note that the coating thickness was 0.05 to 0.2 mm.

Subsequently, as shown in FIG. 22, by press punching, as shown in FIG. 22, a mixture application portion 516 corresponding to the positive electrode plate formed from two rows of band application portions 512 and a non-application portion of the mixture are formed. The uncoated portion 518 corresponding to the bent portion 513 and the lead 520 formed as a part of the lateral end portion 519 (shown in FIG. 21) of the current collector 502.
(Size: width 2 to 3 mm, length 10 to 30 mm), a sheet-shaped mixture application plate 522 for a negative electrode was formed. Note that the leads 520 of these sheet-shaped mixture application plates 522 are bent 90 ° so as to be parallel to the uncoated portions 518 for bending as shown in FIG.
24, and a sheet-shaped mixture application plate 526 for a negative electrode having leads 524 was formed.

The sheet-shaped mixture application plate 526 for the negative electrode
Was folded at the non-application portion 518 for bending to form a two-fold electrode 528 for the negative electrode. Example 4
A two-fold electrode 430 for the negative electrode is prepared, and a bellows electrode for the positive electrode and two types of two-fold electrodes 430, 5 for the negative electrode are prepared.
Using No. 28, a prismatic battery in which the positive electrode plate and the negative electrode plate were alternately opposed to each other with a separator interposed therebetween was formed in the same manner as in Example 4. (Embodiment 6) In the prismatic battery of this embodiment, the positive electrode plate has a bellows-like current collector, and the negative electrode plate has a plurality of independent rectangular current collectors.

In the manufacture of the prismatic battery of the present embodiment, the bellows-like electrode 6 for the positive electrode was used for the positive electrode plate in the same manner as in the first embodiment.
00 was formed. Further, as shown in FIG. 24, the negative electrode plate has a width of 100 to 200 mm and a thickness of 0.01 to 200 mm.
0.02 mm band-shaped current collector 602, mixture 604 composed of carbon and binder, and mixture application tool 606 that can apply mixture 604 on the surface of current collector 602 in a planar manner.
And the front surface 608 and the back surface 61 of the current collector 602.
0, the mixture 604 was applied while forming a band-shaped mixture application portion 612 having a width of 30 to 60 mm. Note that the coating thickness was 0.05 to 0.2 mm.

Subsequently, the current collector 602 is removed by pressing.
Has a lead 615 (size; width 2 to 3 mm, length 10 to 30 mm) consisting of a part of the lateral end portion 614 of
A rectangular electrode plate 616 for an independent negative electrode having a size of 0 to 40 mm and a length of 30 to 60 mm was formed. Using the bellows-like electrode 600 for the positive electrode and the square electrode plate 616 for the negative electrode, as shown in FIG. 25, the electrode plate 616 for the negative electrode was placed in each concave portion of the bellows-like electrode 600 for the positive electrode packed in a separator. 1
Inserted one by one. Compression was performed from both sides in the direction in which the bellows expanded and contracted to form a prismatic battery in which positive and negative electrode plates were alternately opposed to each other with a separator interposed therebetween. (Embodiment 7) In the prismatic battery of this embodiment, the positive electrode plate and the negative electrode plate each have a folded current collector.

In the manufacture of the prismatic battery according to the present embodiment, the positive electrode plate and the negative electrode plate are firstly folded in the same manner as in the fourth embodiment.
2 was formed. Then, as shown in FIG. 26, in a state where the two-fold electrode for the positive electrode 700 is packed in a bag-shaped separator, the two-fold electrode 700 for the positive electrode and the two-fold electrode 702 for the negative electrode are combined. A combination of electrodes 704 was formed.

Combination of two folded electrodes 7
27 were laminated as shown in FIG. 27 to form a prismatic battery in which positive and negative electrode plates were alternately opposed to each other with a separator interposed therebetween.

[0056]

According to the prismatic battery of the present invention, since the deterioration of the battery performance and the short circuit are prevented beforehand, there are few failures and the reliability is high. Further, in comparison with the conventional prismatic battery, the prismatic battery of the present invention can reduce the amount of the mixture used while maintaining the battery performance, particularly the capacity, so that the battery capacity per unit weight of the battery increases. can do. Furthermore, since the amount of the mixture can be reduced with respect to the desired battery capacity, the manufacturing cost can be reduced.

In particular, the bellows-like electrode or the rectangular plate is bent at the bent portion in the horizontal direction, then in the upward direction, in the horizontal direction,
By using an electrode with a current collector that is folded in a rectangular flat plate that is continuous in the downward and downward directions, and that is continuous in the horizontal direction, and that is continuous in the vertical direction, and that is alternately folded in the horizontal direction, Eliminates the need for unification,
Productivity is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a laminated structure of electrodes of a prismatic battery formed in Example 1.

FIG. 2 is a diagram showing a state in which a mixture is applied to a current collector in Example 1.

FIG. 3 is a plan view showing a band-shaped mixture applying plate for a positive electrode before bending formed in Example 1.

FIG. 4 is a front view showing a band-shaped mixture coating plate for a positive electrode before bending formed in Example 1.

FIG. 5 is a diagram showing a state in which a mixture coating plate for a positive electrode is packed in a separator in Example 1;

FIG. 6 is a perspective view showing a bellows-like electrode for a positive electrode, which is formed by being folded in a bellows shape in a state packed in a separator in Example 1.

FIG. 7 is a plan view showing an unfolded band-shaped mixture applying plate for the negative electrode formed in Example 1.

FIG. 8 is a front view showing a band-shaped mixture-applied plate for the negative electrode formed in Example 1 before bending.

FIG. 9 is a diagram showing a state in which a bellows electrode for a positive electrode and a bellows electrode for a negative electrode are combined in the first embodiment.

FIG. 10 is a diagram showing a state in which a mixture is applied to a current collector on a stripe in Example 2.

FIG. 11 is a diagram showing a state in which a mixture coating plate for a positive electrode is formed in Example 2.

FIG. 12 is a front view showing a state where a mixture is applied to a current collector in Example 3.

FIG. 13 is a plan view showing a state where a mixture is applied to a current collector in Example 3.

FIG. 14 is a plan view showing a mixture applying plate for a negative electrode formed in Example 3.

FIG. 15 is a diagram showing an electrode for a negative electrode formed in Example 3.

FIG. 16 is a diagram showing a state in which a bellows electrode for a positive electrode is inserted into an electrode for a negative electrode in Example 3.

FIG. 17 is a diagram showing a state where a mixture is applied to a current collector in Example 4.

FIG. 18 is a plan view showing a sheet-shaped mixture-applied plate for a negative electrode formed in Example 4.

FIG. 19 is a plan view showing a sheet-shaped mixture-applied plate for a negative electrode formed in Example 4.

FIG. 20 is a diagram showing a state in which a bellows electrode for a positive electrode and two types of two-fold electrodes for a negative electrode are combined in Example 4.

FIG. 21 is a diagram showing a state where a mixture is applied to a current collector in Example 5.

FIG. 22 is a diagram showing a sheet-shaped mixture-applied body for a negative electrode formed in Example 5.

FIG. 23 is a diagram showing a sheet-shaped mixture-applied body for a negative electrode formed in Example 5.

FIG. 24 is a diagram showing a state in which a mixture is applied to a current collector and a state in which a negative electrode is formed in Example 6.

FIG. 25 is a diagram showing a state in which a negative electrode plate is combined with a bellows electrode for a positive electrode in Example 6.

FIG. 26 is a diagram showing a state where a two-fold electrode for a positive electrode and a two-fold electrode for a negative electrode are combined in Example 7.

FIG. 27 is a diagram showing a state in which a combination of a two-fold electrode for a positive electrode and a two-fold electrode for a negative electrode is stacked in Example 7.

[Explanation of symbols]

102: mixture containing positive electrode active material 104: current collector 10
6: bent portion 108: positive electrode plate 110: mixture containing negative electrode active material 11
2: current collector 114: negative electrode plate 115: separator

Claims (9)

[Claims] 1. A positive electrode plate in which a mixture containing a positive electrode active material is applied to a sheet-like current collector, and a negative electrode plate in which a mixture containing a negative electrode active material is applied to a sheet-like current collector. And a separator, wherein the positive electrode plate and the negative electrode plate are stacked alternately facing each other with the separator interposed therebetween, wherein at least one of the positive electrode plate and the negative electrode plate is provided. The electrode plate is such that the current collector constituting the one electrode plate is folded at least once, and the mixture is not substantially applied to a bent portion of the current collector. A prismatic battery characterized by the following. 2. The prismatic battery according to claim 1, wherein the current collector has a bellows shape alternately folded, and the mixture is not substantially applied to a bent portion. 3. The current collector has a through hole in a folded portion, and the electrode plate having the current collector is sandwiched between both sides by the separator, and both sides of the electrode plate are interposed through the through hole. The prismatic battery according to claim 1, wherein the separator to be sandwiched is integrally joined. 4. The prismatic battery according to claim 2, wherein both the positive electrode plate and the negative electrode plate have a bellows shape in which the current collectors are alternately folded. 5. The current collector of one of the positive electrode plate and the negative electrode plate has a bellows shape alternately folded in the horizontal direction, and the other current collector has a bellows shape alternately folded in the vertical direction. The one electrode plate and the other electrode plate are stacked so that the one electrode is folded in the horizontal direction and the other electrode is folded in the vertical direction, and the two are alternately stacked. The prismatic battery according to claim 2. 6. The current collector is formed by bending a rectangular flat plate in a laterally extending direction, then in an upward direction, a lateral direction, a downward direction and a laterally extending continuous irregular shape. 3. The prismatic battery according to claim 2, wherein the flat plate is folded and further folded alternately in the lateral direction. 7. The method according to claim 2, wherein one of the positive electrode plate and the negative electrode plate has a bellows-shaped current collector, and the other electrode plate has a folded current collector. Prismatic battery. 8. The electrode plate of one of the positive electrode plate and the negative electrode plate has a bellows-shaped current collector, and the other electrode plate has a plurality of independent rectangular current collectors. The prismatic battery according to claim 1. 9. The prismatic battery according to claim 1, wherein each of the positive electrode plate and the negative electrode plate has a folded current collector.