JP2003123730A - Rectangular sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rectangular sealed battery capable of realizing high output by reducing internal resistance per unit cell. SOLUTION: This rectangular sealed battery has plural cells 20 each provided with: an electrode plate group 8 composed by stacking a positive electrode and a negative electrode by interposing a separator and by projecting one-side parts of the positive electrode and the negative electrode to the sides opposite to each other to form lead parts 9, collectors 10 jointed to the lead parts 9 on both sides of the plate group 8 with connection projecting parts 27 formed protrusively outward; and a bag-like battery case 24 for surrounding the plate group 8 jointed to the collectors 10 with only the connection projecting parts 27 of the collectors 10 projected to the outside. The plural cells 20 are inserted and disposed in a rectangular battery case 21 by connecting the connection projecting parts 27, 27 of the collectors 10 on both the sides thereof with each other and the entire current-carrying path among the electrode groups 8 is straightened and shortened to reduce the internal resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prismatic sealed battery, and more particularly to a prismatic sealed battery in which a plurality of cells are connected to each other to reduce the internal resistance of an assembled secondary battery.

[0002]

2. Description of the Related Art A conventional collective type secondary battery in which a plurality of cells are connected so as to obtain a required power capacity has a plurality of individual rectangular parallelepiped cells arranged in a width of a battery case. The wide long sides are arranged so as to face each other and overlap each other, and end plates are arranged outside the battery case of the unit cells at both ends, and bound by binding bands to integrally connect them. A lead is drawn upward from the upper end of the electrode plate and connected to a terminal mounted on the lid of the battery case, and the terminals are connected to each other between the unit cells by a connecting plate.

Therefore, since the connection paths between the unit cells are long and there are many connection points, the component resistance due to the components including the connection components is large, and this component resistance and the reaction in the battery reaction by the positive electrode plate, the negative electrode plate and the electrolytic solution. Ratio with resistance is 4
It reaches 0 to 50%: 60 to 50%, and heat generation of the battery increases due to a large internal resistance, which is a major obstacle to realization of high output and improvement of life characteristics. Also,
There is also a problem that the cost is high because the connection configuration between the unit cells is complicated and the number of parts is large.

Therefore, the applicant of the present invention has previously described FIG. 13 and FIG.
As shown in FIG. 1, a prismatic sealed battery 1 including a plurality of cells 2 is proposed. Reference numeral 3 denotes the prismatic battery case, which is integrally connected to each other by sharing the battery case 4 of the rectangular parallelepiped unit cell 2 having a narrow short side surface and a wide long side surface, with the short side surface serving as a partition wall 5. Each battery case 4 is formed into a flat rectangular parallelepiped shape.
The upper surface opening of the is closed integrally with the lid 6. Connection holes 7 are formed on the outer short side surfaces of the battery case 4 at both ends and on the partition wall 5 between the battery cases 4 and 4. In each battery case 4, an electrode plate group 8 formed by stacking a rectangular positive electrode plate and a negative electrode plate with a separator interposed therebetween is housed together with an electrolytic solution to form a single battery 2. The positive electrode plate and the negative electrode plate of the electrode plate group 8 are projected to the opposite side portions to form the lead portions 9a and 9b of the positive electrode plate and the negative electrode plate, and the lead portions 9a and 9b are assembled at the side edges thereof, respectively. The electric plates 10a and 10b are connected by welding or the like.

A connection hole 7 is formed on the upper portion of the current collector plates 10a and 10b.
A connection protrusion 11 is fitted in the protrusion, and the connection protrusions 11 of the positive and negative current collector plates 10a and 10b are welded to each other and connected between the adjacent battery cases 4 and 4. Further, a positive or negative connection terminal 12 is mounted in the connection hole 7 on the outer short side of the battery case 4 at both ends, and the connection protrusion 13 and the current collector plate 10a.
Alternatively, the connecting protrusions 11 of 10b are connected to each other by welding. Thus, the plurality of unit cells 2 contained in the rectangular battery case 3 are connected in series and output between the connection terminals 12 at both ends.

Further, the lid 6 has a communication passage 14 for equalizing the internal pressures of the battery cases 4 and 4, and a safety valve for releasing the pressure when the internal pressure of the battery cases 4 exceeds a certain level ( (Not shown), a sensor mounting hole 15 for mounting a temperature sensor for detecting an appropriate temperature of the unit cell 2, and the like are provided.

With such a structure, the positive electrode plate and the negative electrode plate in the electrode plate group 8 are respectively connected to the lead portions 9a and 9b.
Since the energization path up to is short and the lead portions 9a and 9b are connected inside the rectangular battery case 2 via the current collectors 10a and 10, it is compared with the conventional individual cell connected as described above. Since the connection path is short and the number of connection points is small, it is possible to reduce the component resistance due to the components including the connection component, and the internal resistance can be reduced accordingly.

[0008]

However, the above-mentioned FIG.
3, in the configuration as shown in FIG. 14, the lead portions 9a and 9b and the current collecting plates 10a and 1a from the positive electrode plate and the negative electrode plate, respectively.
Although the energization path to 0b is short, as shown by the arrow in FIG. 15, the current collector plates 10a and 10b are welded and connected to each other at one point between the tips of the connecting protrusions 11 at the upper ends thereof. However, there is a problem that the connection path is detoured, the connection path becomes long, and since the connection is made at one place, the internal resistance becomes high.

In view of the above-mentioned conventional problems, it is an object of the present invention to provide a prismatic sealed battery capable of realizing a higher output by further reducing the internal resistance per unit cell.

[0010]

According to the prismatic sealed battery of the present invention, a positive electrode plate and a negative electrode plate are laminated with a separator interposed therebetween, and one side portion of the positive electrode plate and the negative electrode plate are made to project to opposite sides to lead portions. And a current collector that is connected to the lead parts on both sides of the electrode plate and that has connection protrusions protruding outward, and the electrode plate group that is connected to the current collector is connected to the current collector connection protrusion. It has a plurality of cells with a bag-shaped battery case that surrounds only one part of the battery, and connects the projections of the current collectors on both sides of the cells to a rectangular battery. It is inserted and arranged in the tank, and the energization path from the positive electrode plate and the negative electrode plate of the electrode plate group, which is the power generation element of the unit cell, to the respective lead parts and the current collector is short, and also when connecting between unit cells. Connecting the current collectors to each other at any position will directly connect the connecting protrusions, so the current path can be shortened. Since Fuyaseru also connection points number, the internal resistance can be reduced, it is possible to realize a further reduction to high output internal resistance per correspondingly single cell.

Further, the positive electrode plate and the negative electrode plate are laminated with a separator interposed therebetween, and one side portion of the positive electrode plate and the negative electrode plate are protruded to opposite sides to form a lead portion, and both side portions of the electrode plate group are formed. Encloses a current collector that is joined to the lead part and that has a plurality of connecting protrusions protruding outward, and an electrode plate group to which the current collector is joined, with only the connecting protrusions of the current collector protruding outward. A plurality of cells with a bag-shaped battery case and a prismatic battery case with a space for connecting the plurality of cells with their short sides connected to each other. When the connecting projections of the body are joined and inserted into the rectangular battery case, the above effect can be obtained in a compact flat plate rectangular sealed battery in which a plurality of rectangular parallelepiped cells are connected by connecting their short side surfaces. It is possible to realize high output and to eliminate the partition between the cells. Can, the length of that amount rectangular sealed battery short, can be made compact.

Further, when adjacent battery cells are arranged such that their connecting projections are butted against each other and the connecting projections are electron beam welded or laser beam welded through the gaps between the battery cells, a plurality of connecting projections between the battery cells are formed. The welding can be reliably and efficiently welded without adversely affecting the electrode plate group or the bag-shaped battery case.

If the peripheral portion of the through-opening of the connecting projection formed in the bag-shaped battery case and the outer surface of the current collector are sealed with an adhesive or a sealing material, the connecting protrusion is connected through the through-opening of the bag-like battery case. When the sealing of the electrolytic solution in the bag-shaped battery case can be ensured with a simple structure while projecting the part, and the bag-shaped battery container made of a metal current collector and a resin film is sealed by heat welding. In comparison, it is possible to secure the seal of the electrolytic solution with high reliability.

Further, when a pressing member for pressing the peripheral portion of the through opening of the connecting projection formed in the bag-shaped battery case against the outer surface of the current collector is interposed between the adjacent unit cells, the sealing portion is formed by the pressing member. The reliability can be further improved by pressing.

Further, the pressing member has an elastic annular portion surrounding the connection projection, and if the elastic annular portion has a through window penetrating from one side of the unit cell toward the connection projection, the seal member is sealed. The connection projection can be joined from the through window while pressing the entire circumference of the portion to ensure the reliability of the seal.

Further, a resin film is formed by baking around the connection protrusion on the outer surface of the current collector, and the peripheral edge of the through opening of the connection protrusion formed in the bag-shaped battery case and the outer surface of the current collector are heat-welded. Then, it is possible to secure the seal of the electrolytic solution with high reliability and to reduce the cost with a simple configuration without using the pressing member.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a prismatic sealed battery of the present invention will be described below with reference to FIGS. The same components as those of the conventional example described with reference to FIGS. 13 and 14 are designated by the same reference numerals, and differences will be mainly described.

In FIG. 1, the rectangular battery case 21 in the prismatic sealed battery 1 of the present embodiment is a plurality of (six) rectangular parallelepiped cells 2 having narrow short side surfaces and wide wide side surfaces.
0 is connected to its short side surface in a flat, horizontally long rectangular box shape having a housing space 22 capable of housing a cell connecting body 23.
A connection hole 7 for mounting and connecting 2 is formed. The upper surface opening of the prismatic battery case 21 is configured to weld and seal the lid body 6.

As shown in FIG. 2, the unit cell 20 has a large number of positive electrode plates and a large number of negative electrode plates alternately arranged, and each positive electrode plate has a bag-shaped separator having an opening in the lateral direction. The positive electrode plate and the negative electrode plate are laminated with the separator interposed therebetween to form the electrode plate group 8, and one side portion of the positive electrode plate and the negative electrode plate is projected to the opposite side to form the positive electrode and the negative electrode. The lead portions 9 are provided, the current collectors 10 are joined to the respective lead portions 9, and the electrode plate group 8 to which the current collector 10 is joined (hereinafter, simply referred to as the electrode plate group 8) is shaped like a bag together with the electrolytic solution. It is configured to be housed in the battery case 24.

The positive electrode plate is made of Ni foam metal and the lead portion 9
Except that the lead portion 9 is filled with nickel hydroxide, and the lead portion 9 is formed by pressurizing and compressing the foam metal and seam-welding the lead plate to one surface thereof by ultrasonic welding. Further, the negative electrode plate is formed by applying a negative electrode material containing a hydrogen storage alloy to Ni punching metal except for the lead portion 9.

The bag-shaped battery case 24 is formed in a bag shape by joining a synthetic resin sheet 25 having a single-layer or multi-layer laminated structure such as polypropylene or polyethylene by heat welding or adhesion with an adhesive.

In the example shown in FIG. 2, first, as shown in FIG. 2A, a rectangular synthetic resin sheet 2 having a thickness of 100 to 150 μm is used.
5 is wrapped so as to wrap the electrode plate group 8, both side edges are joined by heat seals 26a as shown by hatching, and then, FIG.
As shown in, the lower end of the tubular synthetic resin sheet 25 is joined by a heat seal 26b, a predetermined amount of electrolyte is injected into the inside, and then the upper end of the bag-shaped synthetic resin sheet 25 is heat sealed. 26c, and the joined upper and lower ends are bent to form a unit cell 20 in which the electrode plate group 8 is accommodated in the bag-like battery case 24 together with the electrolytic solution as shown in FIG. 2 (c). Of course, the electrode plate group 8 may be housed together with the electrolytic solution in the bag-shaped battery case 24 formed in advance to seal the upper opening. In addition, the upper end of the bag-shaped battery case 24 is sealed to prevent leakage of the electrolytic solution and leave an opening to the extent that the generated gas can be discharged.

On the current collector 10, a plurality of connecting projections 27 having a rectangular or oval front shape are formed to project outward at appropriate intervals in the longitudinal direction (vertical direction). A through opening 28 is formed in the bag-shaped battery case 24 so that the connecting projection 27 penetrates and projects to the outside. The peripheral edge of the through opening 28 is covered with an adhesive material or a sealing material 29. It is sealed to. In the case of the synthetic resin sheet 25 having good weldability, it may be heat welded.

A plurality of (six) unit cells 20 having the above configuration
As shown in FIG. 3, the short side surfaces, that is, the current collectors 10 on both sides are arranged in parallel so as to face each other, and the connecting protrusions 27 of the adjacent current collectors 20 are arranged to abut each other. And as indicated by arrows in FIG.
An electron beam or a laser beam 30 is irradiated to the abutting edges of the connecting protrusions 27 from the gap between 0 and joined by welding 31.

The through opening 2 formed in the bag-shaped battery case 24
As shown in FIG. 4, the peripheral portion of 8 may be sealed in the current collector 10 with an adhesive material or a sealing material 29.
As shown in FIG. 5, pressing members 32 and 33 having a semi-circular shape or a U shape for pressing the peripheral portion of the through opening 28 of the bag-shaped battery case 24 against the outer surface of the current collector 10 are provided between the adjacent unit cells 20 and 20. It is preferable to interpose and press the sealing portion to improve its reliability. The pressing member 32 shown in FIG. 5 (a) is a semi-circular or U-shaped member having a substantially U-shaped cross-section and bulging the middle portion of the inner and outer peripheries serving as the pressing portion outward in an arc shape. Is configured. The pressing member 33 shown in FIG. 5 (b) has a plurality of pressing tongue pieces 33b which are elastically deformed and pressed at the time of pressing on both surfaces of the pressing portion 33a which can be inserted into the gap between the unit cells 20 and 20. Is configured.

In the example of FIGS. 5 (a) and 5 (b), after the connecting projection 27 of the unit cell 20 is joined by welding 31, the pressing members 32 and 33 divided into two are connected between the unit cells 20 and 20. In order to improve the reliability of the seal, the elastic annular portion 35 having a U-shaped cross section surrounding the connecting projection 27 and having the elastic annular portion is provided as shown in FIG. When the pressing member 34 having the through window 36 penetrating from one side of the unit cell 20 toward the connecting protrusion 27 is used for the elastic ring portion 35,
The connection projection 27 can be joined by irradiating the electron beam or the laser beam 30 through the through window 36 while pressing the entire circumference of the seal portion 5 to secure the reliability of the seal.

As a concrete example of the structure of such a pressing member, as shown in FIG. 7, the entire shape is an elliptical shape and its cross-sectional shape bulges outward in an arc shape, and the semicircular portions at both ends are formed. The two annular plates 38, on which the joint flange 40 is formed, are opposed to each other on the inner and outer peripheries via the falling portion 39, and the joint flange 4 is formed.
The pressing member 37 formed by integrally joining 0 is preferable because it can be easily manufactured. In this pressing member 37, the elastic annular portion 35 is an elliptical portion that bulges outward in an arcuate cross section.
The through window 36 is formed by the fact that the falling portion and the joint brim are not formed on both sides of the parallel portion on both sides.

Since the pressing member 37 shown in FIG. 7 is configured so as to surround the periphery of the single connecting projection 27, it is provided in the current collector 10 between the adjacent unit cells 20 and 20. It is necessary to dispose as many pressing members 37 as the number of the connecting protrusions 27. Therefore, in order to improve workability during assembly, it is preferable that the same number of pressing members 37 as the connecting protrusions 27 provided on the current collector 10 are integrally connected by a connecting piece.

Further, in the above description, the peripheral portion of the through opening 28 formed in the bag-shaped battery case 24 is sealed with the current collector 10 by the adhesive material or the sealing material 29, and the pressing members 32, 33,
An example in which the seal portion is pressed by 34 and 37 to improve the reliability is shown.
The reaction force of the pressing force of 3, 34, 37 is received by the current collector 10 and acts so as to peel off the weld 31 of the connecting projection 27, which may be not preferable.

Therefore, as shown in FIG. 8, a synthetic resin film 45 made of polypropylene resin, polyethylene resin, epoxy resin or the like is baked around the connection protrusion 27 of the current collector 10, and the resin film 45 is formed into a bag. 2 of the battery case 24
It is also possible to heat-weld the peripheral portion of 8 and seal the through opening 28 of the bag-shaped battery case 24 to the current collector 10. This resin film 45
Can be formed by impregnating the powder resin around the connection protrusion 27 of the current collector 10 and charging it into a heating furnace at about 160 to 220 ° C., depending on the type of resin. At this time, it is preferable that the resin film is made of the same material as the bag-shaped battery case.

When the bag-shaped battery case 24 is heat-welded to the resin film 45 formed by baking on the current collector 10 as described above, it is possible to maintain high reliability with respect to the sealing property with respect to the electrolytic solution, and by using the pressing member separately. Since the sealing property can be secured without pressing, the number of parts can be reduced and the cost can be reduced.

Further, as shown in FIGS. 9 to 11, an annular leaf spring 46 is used as a pressing member, and an annular leaf spring is provided on a locking step portion 47 formed on the outer periphery of the tip of the connecting projection 27 of the current collector 10. Even when the inner peripheral edge portion of 46 is locked, the reaction force of the pressing member arranged between the current collectors 10 and 10 does not act to separate the current collectors 10 and 10. The annular leaf spring 46 is an annular shape that surrounds the periphery of the connecting protrusion 27,
A pressing plane 48 (indicated by diagonal lines in FIG. 10) that presses the peripheral portion of the through opening 28 of the bag-shaped battery case 24 is formed on the outer peripheral portion, and is inclined or curved so that the inner peripheral side thereof projects toward one side. The protruding height of the inner peripheral edge of the molded body is set to be higher than the height dimension from the outer surface of the current collector 10 to the locking step 47 of the connecting protrusion 27, and the inner peripheral portion is connected by elastic deformation. The elastic plate portion 50 is divided and formed by forming cuts 49 at appropriate intervals in the circumferential direction so that the elastic plate portion 50 passes through the tip portion of the protrusion 27 and is locked by the locking step portion 47.

Thus, the annular leaf spring 46 is used as the pressing member.
When using, a sealing material such as a seal rubber or a pitch or an adhesive material 29 is arranged around the connection protrusion 27 of the current collector 10, the electrode group 8 is covered with the bag-shaped battery case 24, and the connection protrusion 27 penetrates. The peripheral portion of the through opening 28 protruding by
The outer periphery of the ring-shaped leaf spring 46 and connect the inner circumferential portion of the annular leaf spring 46 to the connecting protrusion 27
By pushing it into the locking step portion 47 of
A unit cell 20 having a highly reliable seal around the periphery thereof is configured. After that, the connecting protrusions 27 of these unit cells 20
The unit cell connecting body 23 can be constructed by connecting them with the welding 31, and the prismatic sealed battery 1 can be constructed by housing this in the prismatic battery case 21.

At both ends of the prismatic closed type battery 1, as shown in FIGS.
The connecting protrusions 12a of the connecting terminals 12 are fitted into the connecting holes 7 formed in the upper portions of both end walls of each of the unit cells 2 at both ends.
It is resistance-welded and joined to the upper end portion of the current collector 10 on the outside of 0. Therefore, the opening 41 is formed in a portion of the bag-shaped battery case 24 that covers the outer surface of the unit cell 20 and faces the connection protrusion 12a. An O-ring 42 is attached to the outer periphery of the base of the connecting projection 12a to seal the outer surfaces of both end walls of the rectangular battery case 21 and to connect the inner surface of both end walls of the rectangular battery case 21 with the connecting hole 7. An O-ring 43 is attached to the periphery of the connector to seal the periphery of the opening 41 of the bag-like battery case 24, and the penetrating portion of the connection terminal 12 has a double seal structure.

According to the prismatic sealed battery 1 having the above structure,
The current-carrying paths from the positive electrode plate and the negative electrode plate of the electrode plate group 8 which is the power generation element of the unit cell 20 to the respective lead portions 9 and the current collector 10 are short, and the current collector is also used in the connection between the unit cells 20 and 20. Since the plurality of connecting protrusions 27, 27 are directly joined to each other, the current-carrying path in the rectangular sealed battery 1 is straightened and shortened, and the unit cells 2 are connected.
Since the number of energization paths between 0 and 20 is plural, the internal resistance can be remarkably reduced, and the unit cell 20 of the polygonal sealed battery 1 can be reduced.
The internal resistance per hit can be further reduced to achieve higher output.

In addition, in the compact flat plate-shaped prismatic sealed battery 21 in which a plurality of rectangular parallelepiped unit cells 20 are connected with their short side faces connected to each other, it is not necessary to provide a partition wall between the unit cells 20 and 20. The length of the rectangular battery case 21 can be shortened by that much, and the structure can be made compact.

Further, the adjacent cells 20 are arranged such that their connecting projections 27, 27 are butted against each other.
Since the connecting projections 27, 27 are electron beam welded or laser beam welded from the gap between 0, the unit cells 20, 2,
It is possible to perform reliable and efficient welding and joining of the plurality of connecting projections 27 between 0 without adversely affecting the electrode plate group 8 and the bag-shaped battery case 24.

The connecting projection 2 formed on the bag-shaped battery case 24
Since the peripheral portion of the through opening 28 of 7 and the outer surface of the current collector 10 are sealed with the adhesive material or the sealing material 29, the connecting projection 27 is projected from the through opening 28 of the bag-shaped battery case 24. It is possible to secure the seal of the electrolytic solution in the bag-shaped battery case 24 with a simple configuration. It is also possible to seal the bag-shaped battery case 24 made of the metal current collector 10 and the resin film or the like by heat welding, but by sealing with the adhesive material or the sealing material 29, higher reliability can be obtained. It is possible to secure the seal of the electrolytic solution. Further, in the case of heat welding, if a resin film 45 of the same resin as the bag-shaped battery case 24 is formed on the current collector 10 by baking, a highly reliable seal can be secured.

Further, between the adjacent unit cells 20 and 20,
Pressing members 32, 3 for pressing the peripheral portion of the through opening 28 of the connecting projection 27 formed in the bag-shaped battery case 24 against the outer surface of the current collector 10.
Since pressing members such as 3, 34 and 37 are interposed, reliability can be further improved by pressing the sealing portion with this pressing member.

In particular, as the pressing member, there is an elastic annular portion 35 that surrounds the periphery of the connecting protrusion 27, and the elastic annular portion 3 is provided.
When the pressing members 34 and 37 having the through windows 36 penetrating from one side of the unit cell 20 toward the connecting protrusion are used for 5, while the reliability of the seal is ensured by pressing the entire circumference of the seal portion. The connection projection 27 can be joined from the through window 36, and both workability and seal reliability can be satisfied. Further, when the annular leaf spring 46 that is locked to the connecting protrusion 27 is used as the pressing member, the reaction force of the pressing force is applied to the connecting protrusion 2.
It is more preferable because it does not act to separate the joint portions of the Nos. 7 and 27 from each other and the joining of the connecting protrusions 27 is not hindered.

In the above embodiment, the prismatic battery case 21 is made of synthetic resin, but in the present invention, each unit cell 2
0 has a bag-shaped battery case 24, and the electrolytic solution is stored and sealed inside the bag-shaped battery container 24, so that the rectangular battery container 21 made of metal can be used to house and arrange the unit cells as it is, and further the inner surface The use of the metal battery case 21 provided with the insulating coating makes it possible to obtain high reliability with respect to the insulating property, ensure high cooling performance, and effectively suppress the temperature rise of each cell 20. it can.

Further, in the above embodiment, an example in which the present invention is applied to the flat rectangular prismatic battery 1 in which a plurality of rectangular parallelepiped unit cells 20 are incorporated with their short side surfaces connected to each other is shown. , For example, in a box-shaped rectangular battery case, a plurality of flat plate-shaped storage spaces are formed in parallel through the cooling passages, and in each flat plate-shaped storage space, the unit cells connected as described above are stored and arranged. Between the ends of the accommodation space, the connection fittings and the connection protrusions arranged in the rectangular battery case are welded and connected,
The plurality of unit cells 20 may be arranged in a matrix.

[0043]

As is apparent from the above description, according to the prismatic sealed battery of the present invention, a plurality of connecting projections are formed on the current collector so as to project outward, and the current collector is joined. A unit cell is constructed by enclosing a group of electrode plates in a bag-shaped battery case with only the connecting projections of the current collector protruding to the outside, and connecting the multiple battery cells to the connecting projections of the current collectors on both sides. Since they are connected to each other and inserted and arranged in a rectangular battery case, the current-carrying paths from the positive electrode plate and negative electrode plate of the electrode plate group, which are the power generating elements of the single battery, to the respective lead parts and current collectors are short, Even when connecting between the current collectors, the current-carrying paths can be shortened by directly connecting the current collectors to each other at any position, and the number of connection points can also be increased, so the internal resistance can be reduced and the internal per battery unit can be reduced accordingly. It is possible to further reduce the resistance and achieve higher output.

Further, by arranging adjacent unit cells so that their connecting projections are butted against each other and performing electron beam welding or laser welding between the connecting projections through the gaps between the unit cells, a plurality of connecting projections between the unit cells can be formed. It is possible to perform reliable and efficient welding joining without adversely affecting the electrode plate group and the bag-shaped battery case.

If the peripheral portion of the through-opening of the connecting projection formed in the bag-shaped battery case and the outer surface of the current collector are sealed with an adhesive or a sealant, the connecting protrusion will pass through the through-opening of the bag-like battery case. It is possible to secure the sealing of the electrolytic solution in the bag-shaped battery case with a simple structure while projecting the portion with high reliability.

Further, when a pressing member for pressing the peripheral portion of the through opening of the connecting projection formed in the bag-shaped battery case against the outer surface of the current collector is interposed between the adjacent unit cells, the sealing portion is formed by the pressing member. The reliability can be further improved by pressing.

Further, the pressing member has an elastic annular portion surrounding the connection protrusion, and if the elastic annular portion has a through window penetrating from one side of the unit cell toward the connection protrusion, the seal member is sealed. The connection projection can be joined from the through window while pressing the entire circumference of the portion to ensure the reliability of the seal.

Further, a resin film is formed by baking around the connection projection on the outer surface of the current collector, and the peripheral edge of the through opening of the connection projection formed in the bag-shaped battery case and the outer surface of the current collector are heat-welded. Then, it is possible to secure the seal of the electrolytic solution with high reliability and to reduce the cost with a simple configuration without using the pressing member.

[Brief description of drawings]

FIG. 1 is an exploded perspective view for explaining an assembly process of an embodiment of a prismatic sealed battery of the present invention.

FIG. 2 is a perspective view showing a step of forming a unit cell by housing the electrode plate group in a film battery case in the same embodiment.

FIG. 3 is a perspective view showing a process of connecting the unit cells to form a unit cell connecting body in the embodiment.

FIG. 4 is a transverse cross-sectional view showing a step of welding and joining the connection protrusions of the unit cells in the same embodiment.

FIG. 5 is a transverse cross-sectional view of a configuration example in which a through-hole of the connection projection of the film battery case is sealed with a pressing member in the same embodiment.

FIG. 6 is a transverse cross-sectional view showing a step of welding and joining the connection protrusions in a state in which the through opening of the connection protrusion of the film battery case is sealed by the pressing member in the same embodiment.

FIG. 7 shows a specific configuration example of a pressing member in the same embodiment, (a) is a front view, (b) is a side view, (c) is a sectional view taken along the line AA of (a) in an installed state, (D) is a sectional view taken along the line BB of (a).

FIG. 8 is a cross-sectional view of another configuration example for sealing the through opening of the connection protrusion of the film battery case in the same embodiment.

FIG. 9 is a cross-sectional view of another configuration example in which the pressing member seals the through opening of the connection protrusion of the film battery case in the same embodiment.

FIG. 10 is a view on arrow CC of FIG.

11 is an enlarged cross-sectional view taken along the line DD of FIG.

12A and 12B show a structure of a connecting portion of connecting terminals at both ends of the rectangular battery case of the same embodiment, FIG. 12A is a vertical sectional front view, and FIG. 12B is an exploded detailed view of a main portion.

FIG. 13 is a partial vertical sectional front view of a prismatic sealed battery of a conventional example.

FIG. 14 is a perspective view showing a cutaway part of the battery case in the conventional example.

FIG. 15 is an explanatory diagram of an energization path in the conventional example.

[Explanation of symbols]

1 prismatic sealed battery 8 electrode group 9 Lead part 10 Current collector 20 cells 21 Square battery case 24 bag-shaped battery case 27 Connection protrusion 28 through-opening 29 Adhesives or sealants 30 electron beam or laser beam 31 welding 32, 33, 34, 37 pressing member 35 Elastic Ring 36 Through window

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinsuke Fukuda             Panasonic 555, Sakaijuku, Kosai City, Shizuoka Prefecture             Que Eve Energy Co., Ltd. (72) Inventor Shinji Hamada             Panasonic 555, Sakaijuku, Kosai City, Shizuoka Prefecture             Que Eve Energy Co., Ltd. (72) Inventor Toyohiko Eto             Panasonic 555, Sakaijuku, Kosai City, Shizuoka Prefecture             Que Eve Energy Co., Ltd. (72) Inventor Masato Onishi             Panasonic 555, Sakaijuku, Kosai City, Shizuoka Prefecture             Que Eve Energy Co., Ltd. F-term (reference) 4E066 CA14                 5H022 AA02 BB11 BB17 CC12 CC13                       CC25 CC27                 5H028 AA01 BB01 BB05 CC01 CC05                       CC08 CC24 FF02

Claims (7)

[Claims] 1. A positive electrode plate and a negative electrode plate are laminated with a separator interposed therebetween, and one side portion of the positive electrode plate and the negative electrode plate are projected to opposite sides to form a lead portion, and an electrode plate group on both sides of the electrode plate group. A bag that encloses a current collector that is joined to the lead part and that has a connecting protrusion protruding outward, and an electrode plate group that is joined to the current collector with only the connecting protrusion of the current collector protruding to the outside. A rectangular sealed battery characterized in that it has a plurality of cells equipped with a battery case, and the plurality of cells are inserted and arranged in a rectangular battery case by connecting the connecting projections of the current collectors on both sides thereof. Battery. 2. A positive electrode plate and a negative electrode plate are laminated with a separator interposed therebetween, and one side portion of the positive electrode plate and the negative electrode plate are projected to opposite sides to form a lead portion, and an electrode plate group on both sides of the electrode plate group. A bag that encloses a current collector that is joined to the lead part and that has a connecting protrusion protruding outward, and an electrode plate group that is joined to the current collector with only the connecting protrusion of the current collector protruding to the outside. Consisting of a plurality of unit cells provided with a battery case, and a rectangular battery case having a space in which the plurality of unit cells are arranged such that their short side surfaces are connected to each other,
A prismatic sealed battery characterized in that a plurality of unit cells are connected to each other by connecting the connecting projections of current collectors to each other and are inserted and arranged in a prismatic battery case. 3. The adjacent cells are arranged such that their connecting projections are butted against each other, and the connecting projections are electron beam welded or laser beam welded through the gap between the single cells. The prismatic sealed battery described. 4. The adhesive or sealing material is used to seal the peripheral portion of the through opening of the connecting protrusion formed in the bag-shaped battery case and the outer surface of the current collector. Prismatic sealed battery. 5. A pressing member for pressing the peripheral portion of the through-opening of the connecting protrusion formed in the bag-shaped battery case to the outer surface of the current collector is interposed between adjacent unit cells. 4. The prismatic sealed battery according to 4. 6. The pressing member has an elastic annular portion that surrounds the periphery of the connecting protrusion, and the elastic annular portion has a through window penetrating from one side of the unit cell toward the connecting protrusion. The prismatic sealed battery according to claim 5. 7. A resin film is formed by baking around the connection protrusion on the outer surface of the current collector, and the peripheral edge of the through opening of the connection protrusion formed in the bag-shaped battery case and the outer surface of the current collector are heat-welded. The prismatic sealed battery according to claim 1 or 2, characterized in that.