JP2007048668A - Battery and battery pack - Google Patents

Abstract

Provided are a battery and an assembled battery that can accurately define the position of electrode terminals in the thickness direction without causing a significant increase in heat capacity, weight, cost, and the like.
In a thin battery, a positive electrode terminal and a negative electrode terminal are formed with step-shaped convex portions in the inner space in the vertical direction in the thickness direction of the thin battery. . The thickness formed by the upper step portion 212 and the lower step portion 213 is substantially equal to the thickness of the power generation element 108, whereby the upper step portion 212 is formed on the inner wall of the upper exterior member 106. The portions 213 are formed in contact with the inner wall of the lower exterior member 107, respectively. Accordingly, the positions and postures of the positive terminal 210 and the negative terminal 220 are maintained by the upper exterior member 106 and the lower exterior member 107, and the position of the external lead-out portion 215 in the thickness direction of the thin battery 10 is maintained with high accuracy. be able to.
[Selection] Figure 2

Description

  The present invention relates to a battery such as a lithium secondary battery in which a power generation element including an electrode plate and an electrolyte is accommodated in an exterior member and sealed.

The power generation element in which the positive electrode plate and the negative electrode plate are alternately stacked via the separator is covered and accommodated with the exterior material and sealed, and the electrode terminals connected to the positive electrode plate and the negative electrode plate are led out from the outer peripheral edge of the exterior material. A stacked secondary battery is known (see, for example, Patent Document 1). As an exterior material of such a secondary battery, a laminate film in which a resin layer is formed on both front and back surfaces of a metal foil is usually used.For example, by sandwiching a power generation element between two laminate films and thermally welding the periphery, The inside of the battery containing the power generation element and the like is sealed.
Japanese Patent Laid-Open No. 9-259859

By the way, in the battery of the form which accommodates two exterior materials in which the recessed part (a cup shape part, and a convex part when it sees from the outside) in each is accommodated, the depth of two cup-shaped exterior materials to match | combine Are equal, the welding position of the exterior material is formed at an intermediate position in the thickness direction of the power generation element, and the electrode terminal is led out to the outside at the intermediate position in the thickness direction.
However, in the battery of such a form, the electrode terminal has a planar structure, and both the metal foil and the laminate film of the exterior material have high flexibility, so the planar position of the electrode terminal, that is, the battery thickness of the electrode terminal. There is a problem that it is difficult to accurately determine the position of the direction. Moreover, when the electrode terminal moves, a load such as the weight of the electrode terminal is applied to the connection part between the electrode plate and the electrode terminal inside the battery, which may affect the life of the part.

As a thin battery that solves such a problem, the positive electrode terminal and the negative electrode terminal are formed so as to have a thickness substantially equal to the total thickness of the power generation element constituted by laminating the separator, the positive electrode plate, and the negative electrode plate, A battery is also disclosed in which the electrode terminal portion surrounds the periphery of the power generation element together with the exterior material to form a battery internal space (see, for example, Patent Document 2).
However, in such a battery, since the volume of the electrode terminal is significantly increased, the heat capacity is also greatly increased, and it is difficult to weld the exterior material and the terminal, and there is a problem that it is difficult to ensure the sealing property. Also, with such a configuration, there is a problem that the weight of the battery also increases greatly. In addition, there is a problem that the amount of members used as electrode terminals increases and the cost increases.
JP 2004-87432 A

  The present invention has been made in view of such problems, and its purpose is to define the position of the electrode terminal in the thickness direction with high accuracy without causing a significant increase in heat capacity, weight, cost, and the like. It is an object of the present invention to provide a battery that can be used, and an assembled battery that is formed by combining the batteries.

In order to solve the above-mentioned problem, the electrode terminal is bent so that the electrode terminal comes into contact with the exterior material or the surrounding structural member at an arbitrary position other than the joint portion of the exterior material. Reduced the addition to the joint with the exterior material.
That is, the battery according to the present invention is a thin battery in which a power generation element is covered and accommodated by an exterior material, and a terminal connected to the power generation element is derived from a peripheral portion of the exterior material, and the terminal is the thin battery. It has the convex part formed in convex shape on both sides of the thickness direction, respectively.

  Preferably, the convex portion is formed inside the exterior material, and the convex portions respectively formed on both sides in the thickness direction are formed so as to contact the inner wall of the exterior material, respectively. Preferably, the convex portion has a maximum dimension in the thickness direction of the terminal defined by a distance between the outermost ends in the terminal thickness direction of the convex portion being substantially equal to a thickness of the electrode plate laminate of the power generation element, or Slightly larger.

Preferably, the convex portion is formed outside the exterior material, and the convex portion formed on both sides in the thickness direction is in contact with a predetermined structure disposed outside the battery. More preferably, the maximum dimension in the thickness direction of the terminal defined by the distance between the outermost ends in the terminal thickness direction of the convex portion is approximately equal to or slightly larger than the thickness of the battery. .
Further, the assembled battery according to the present invention includes a battery stack in which any of the batteries described above are stacked, and a holding that integrally fixes and holds the battery stack by applying pressure in the thickness direction to the battery stack. Member.

  The present invention has been made in view of such problems, and its purpose is to define the position of the electrode terminal in the thickness direction with high accuracy without causing a significant increase in heat capacity, weight, cost, and the like. It is an object of the present invention to provide a battery that can be used, and an assembled battery that is formed by combining the batteries.

First Embodiment A thin battery according to a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1A is a top view of the thin battery 10 and FIG. 1B is a perspective view thereof.
2A is a side view in the longitudinal direction of the thin battery 10, FIG. 2B is a perspective view thereof, and is a cross-sectional view taken along line AA of FIG. 1A, and FIG. ) Is a side view of the thin battery 10 in the short direction, and FIG. 3C is a perspective view thereof, and is a cross-sectional view taken along line BB in FIG.
The thin battery 10 of the present embodiment is a lithium-based flat-stacked type thin secondary battery. The thin battery 10 is used as a unit battery, and a desired output is obtained by stacking a desired number of the batteries. An assembled battery having a desired capacity is constituted by the voltage.

As shown in FIGS. 1 to 3, the thin battery 10 includes a power generation element 108, a positive terminal 210, a negative terminal 220, an upper exterior member 106, and a lower exterior member 107.
The power generation element 108 includes an electrode group formed by alternately stacking positive and negative electrode plates with a separator interposed therebetween, and an electrolyte. The number of these positive electrode plates, negative electrode plates, and separators is arbitrary, but as an example, there are three positive electrode plates, three negative electrode plates, and five separators.

The positive electrode plate has a configuration in which positive electrode layers are formed on both main surfaces of a part of the positive electrode side current collector extending to the positive electrode terminal 210, and the positive electrode terminal 210 made of metal foil is interposed through the positive electrode side current collector. Connected to. The positive electrode side current collector is formed of an electrochemically stable metal foil such as an aluminum foil, an aluminum alloy foil, a copper foil, or a nickel foil. The positive electrode layer is a positive electrode such as a lithium composite oxide such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), or lithium cobaltate (LiCoO ₂ ), or a chalcogen (S, Se, Te) compound. It is formed by applying a mixture of an active material, a conductive agent such as carbon black, and an adhesive such as an aqueous dispersion of polytetrafluoroethylene to a positive electrode side current collector, followed by drying and rolling.

The negative electrode plate has a configuration in which negative electrode layers are formed on both main surfaces of a part of the negative electrode side current collector extending to the negative electrode terminal 220, and the negative electrode terminal 220 made of metal foil is interposed through the negative electrode side current collector. Connected to. In addition, the negative electrode side current collector is formed of an electrochemically stable metal foil such as a nickel foil, a copper foil, a stainless steel foil, or an iron foil. In addition, the negative electrode layer is made of, for example, a negative electrode active material that occludes and releases lithium ions of a positive electrode active material such as amorphous carbon, non-graphitizable carbon, graphitizable carbon, or graphite, and is a precursor material for an organic fired body. As a main material, an aqueous dispersion of styrene butadiene rubber resin powder is mixed, dried, pulverized, and carbonized styrene butadiene rubber is supported on the surface of the carbon particles. The negative electrode plate is formed by further mixing a binder such as an acrylic resin emulsion with the negative electrode plate, applying the mixture to the negative electrode side current collector, and drying and rolling.
Note that when amorphous carbon or non-graphitizable carbon is used as the negative electrode active material, there is no sudden decrease in output, which is advantageous when used as a power source for an electric vehicle.

The separator is suitable for preventing a short circuit between the positive electrode plate and the negative electrode plate and having a function of holding an electrolyte. The separator is a microporous film made of polyolefin such as polyethylene (PE) or polypropylene (PP), for example, and when an overcurrent flows, the pores of the layer are blocked by the heat generation and the current is blocked. Have.
The separator is not limited to a single-layer film such as polyolefin, but a film having a three-layer structure formed by sandwiching a polypropylene film with a polyethylene film, or a film in which a polyolefin microporous film and an organic nonwoven fabric are laminated may be used. it can. By forming the separator in multiple layers as described above, various functions such as an overcurrent prevention function, an electrolyte holding function, and a separator shape maintenance (stiffness improvement) function can be provided.

  The upper exterior member 106 and the lower exterior member 107 are composed of three layers of a metal foil, an inner resin sheet formed of a resin excellent in electrolytic solution resistance, and a surface resin sheet formed of a resin excellent in electrical insulation. It is a laminated film with a structure. Specifically, for example, an aluminum foil is preferable as the internal metal foil, and a polyamide-based resin such as nylon or a polyester-based resin is preferable as the surface resin sheet as the outer layer. Further, as the inner resin sheet, for example, polyethylene, modified polyethylene, polypropylene, modified polypropylene, or ionomer is suitable. Since these resins are excellent in heat weldability, they are more suitable in the case of a structure in which the upper exterior member 106 and the lower exterior member 107 are thermally welded.

  The positive electrode terminal 210 and the negative electrode terminal 220 are respectively connected to the positive electrode plate and the negative electrode plate in the battery internal space 111, and are led out to the outside of the battery through the joint portion of the exterior material. The positive electrode terminal 210 and the negative electrode terminal 220 of the thin battery 10 according to the present embodiment are portions led out of the thin battery 10 as shown in FIGS. 1 (A), 2 (A), and 3 (A). This is the same flat plate shape as a conventional normal thin battery. However, the portion extending into the internal space 111 of the thin battery 10 has slits 211 and 221 formed in the extending direction as shown in FIG. 1B, and two plate-like portions 212 and 213, and 222 and 223 are separated.

Of the two plate-like portions 212 and 213 and 222 and 223 of each of the positive electrode terminal 210 and the negative electrode terminal 220, one portion 212 and 222 is inside the battery as shown in FIGS. 2B and 3B. In the space 111, the thin battery 10 has a shape that is bent in a stepped manner (to form a step) upward in the thickness direction, and the upper surface of the stepped (stepped) portion is the upper exterior member 106. It is configured to contact the inner wall.
Further, of the two plate-like portions 212 and 213 and 222 and 223 of each of the positive electrode terminal 210 and the negative electrode terminal 220, the other portions 213 and 223 are as shown in FIGS. 2B and 3B. In the battery internal space 111, the thin battery 10 is bent downward in the thickness direction of the thin battery 10, and the lower surface of the stepped portion is in contact with the inner wall of the lower exterior member 107. Yes.

The shapes of the positive terminal 210 and the negative terminal 220 will be described in more detail with reference to FIG.
4A and 4B are diagrams illustrating the shape of the positive electrode terminal 210 (the negative electrode terminal 220 has the same shape), FIG. 4A is a perspective view, FIG. 4B is a top view, and FIG. Is a side view, and FIG. 4D is a rear view as seen from the outside.
As shown in FIG. 4, the positive electrode terminal 210 has a flat plate-like portion led out to the outside, but a slit 211 is formed in the extending direction in the portion extending into the internal space 111 of the thin battery 10. It is separated into two plate-like portions 212 and 213. Then, one separated plate-like portion 212 has a shape bent stepwise in the thickness direction upward when attached to the thin battery 10, and the other plate-like portion 213 has the positive electrode terminal 210. When attached to the thin battery 10, the shape is such that it is bent in a staircase shape (stepped shape) in the lower report in the thickness direction. Actually, the portion bent in the thickness direction is slightly inclined to form a “Y” -shaped member as shown in FIG. 4 (A) or FIG. 4 (C).
In such a positive electrode terminal 210 (negative electrode terminal 220), the positive electrode terminal 210 is defined by the distance between the convex portion 212 in the upward direction and the convex portion 213 in the downward direction, that is, the dimension between the tips of the convex portion 212 and the convex portion 213. Is approximately the same as or slightly thicker than the thickness of the power generation element 108 of the thin battery 10 to which it is attached.
To form.

The operation when the positive electrode terminal 210 and the negative electrode terminal 220 are mounted on the thin battery 10 in the form shown in FIGS. 1 to 3 will be described with reference to FIG.
FIG. 5 is a diagram illustrating a state where the positive electrode terminal 210 is installed in the thin battery 10.
As shown in FIG. 5, the thickness formed by the upper step portion 212 and the lower step portion 213 of the positive terminal 210 is substantially equal to the thickness of the power generation element 108 as described above. Thus, the upper step 212 is formed in contact with the inner wall of the upper exterior member 106, and the lower step 213 is formed in contact with the inner wall of the lower exterior member 107.
As a result, the position and orientation of the positive electrode terminal 210 are held by the upper exterior member 106 and the lower exterior member 107, and the parallelism with the upper and lower surfaces of the power generation element 108 or the upper exterior member 106 and the lower exterior member 107 is maintained. can do. In addition, the position of the external lead-out portion 215 in the thickness direction of the thin battery 10 can be maintained with high accuracy.

  When the positive electrode terminal is composed of a simple plate-like member, it is difficult to maintain the terminals in parallel because the flexibility of the exterior material is high, and it is difficult to maintain the position of the terminals with high accuracy. A load is applied to the connection portion between the electrode plate and the electrode plate. However, the configuration as in the present embodiment can solve all such problems.

  The positive electrode terminal 210 and the negative electrode terminal 220 are not particularly limited as long as they are electrochemically stable metal materials. As the positive electrode terminal 210, for example, an aluminum foil, an aluminum alloy foil, copper, etc. A foil, nickel foil, etc. can be mentioned. Moreover, as the negative electrode terminal 220, nickel foil, copper foil, stainless steel foil, iron foil, etc. can be mentioned similarly to the above-mentioned negative electrode side collector.

Second Embodiment A thin battery according to a second embodiment of the present invention will be described with reference to FIGS.
6A is a top view of the thin battery 20, and FIG. 6B is a perspective view thereof.
7 is a side perspective view of the thin battery 20 in the longitudinal direction and is a cross-sectional view taken along the line AA of FIG. 6A. FIG. 8 is a side perspective view of the thin battery 20 in the lateral direction. It is sectional drawing in BB of FIG. 6 (A).
The basic configuration of the thin battery 20 of the second embodiment is the same as that of the thin battery 10 of the first embodiment, and only the positive electrode terminal and the negative electrode terminal according to the present invention are different. Therefore, in the following description, the form of the positive electrode terminal and the negative electrode terminal which are the differences will be mainly described, and the same components as those of the thin battery 10 of the first embodiment are denoted by the same reference numerals, Description is omitted.

As shown in FIG. 6, the thin battery 20 includes a power generation element 108, a positive terminal 230, a negative terminal 240, an upper exterior member 106, and a lower exterior member 107.
As in the thin battery 10 of the first embodiment, the power generation element 108 includes an electrode group and an electrolyte formed by alternately stacking positive and negative plates with a separator interposed therebetween.

  The positive electrode terminal 230 and the negative electrode terminal 240 are respectively connected to the positive electrode plate and the negative electrode plate in the battery internal space 111 and led out to the outside of the battery through the joint portion of the exterior material. Also in the thin battery 20 of the present embodiment, the lead-out portion 250 led out from the battery 20 of the positive electrode terminal 230 and the negative electrode terminal 240 is the same as the conventional thin battery as shown in FIGS. It is the same flat plate shape. However, as shown in FIG. 7, the portion of the thin battery 20 that extends into the internal space 111 has a wavy shape in the thickness direction of the thin battery 20.

The shapes of the positive terminal 230 and the negative terminal 240 will be described in more detail with reference to FIG.
FIG. 9 is a diagram showing the shape of the positive electrode terminal 230 (the negative electrode terminal 240 has the same shape), FIG. 9A is a perspective view, FIG. 9B is a top view, and FIG. Is a side view, and FIG. 9D is a rear view as seen from the outside.
As shown in FIG. 9, in the positive electrode terminal 230, the portion 235 leading to the outside has a flat plate shape. However, the positive electrode terminal 230 is thin from the portion past the welding region with the exterior material from the outside to the inside of the thin battery 20. The battery 20 is bent upward in the thickness direction and rises to a predetermined height. After reaching a predetermined height position (top 231), it is then bent by approximately 180 degrees, extended downward in the thickness direction of the thin battery 20, and lowered to a predetermined height position (bottom 232). Yes. Then, the lower end 232 is bent by approximately 90 degrees, and the end to the edge of the positive electrode terminal 230 is parallel to the lead-out portion 235, in other words, arranged along the lower inner wall of the lower exterior member 107. As shown, the power generation element 108 has a shape parallel to the electrode plate.

  At this time, the distance between the highest portion 231 of the positive electrode terminal 230 and the lower portion 232 which is the lowest position, that is, the height of the positive electrode terminal 230 is substantially the same as the height of the power generation element 108, or The height is slightly higher than 108.

When the positive electrode terminal 230 and the negative electrode terminal 240 are applied to the thin battery 20, the thickness of the positive electrode terminal 230 formed by the wavy shape of the positive electrode terminal 230 is as described above, as shown in FIGS. Thus, the top portion 231 is formed on the inner wall of the upper exterior member 106 and the bottom portion 232 is formed on the inner wall of the lower exterior member 107 so as to be in contact with each other.
As a result, the position and orientation of the positive electrode terminal 230 are maintained by the upper exterior member 106 and the lower exterior member 107, and the parallelism with the upper and lower surfaces of the power generation element 108 or the upper exterior member 106 and the lower exterior member 107 is maintained. Can do. In addition, the position of the external lead-out portion 235 in the thickness direction of the thin battery 10 can be maintained with high accuracy.
That is, even with such a configuration, the same effect as the thin battery 10 of the first embodiment can be obtained.

Third Embodiment and Fourth Embodiment In the first embodiment and the second embodiment described above, the positive electrode terminal and the negative electrode terminal having two types of shapes are exemplified, but the positive electrode terminal and the negative electrode for constituting the battery according to the present invention. As the terminal, various shapes can be considered. Here, two types of shapes are shown as the third embodiment and the fourth embodiment.
Note that the configuration and operation of the battery main body and the method of mounting the positive electrode terminal and the negative electrode terminal are the same as those in the above-described embodiments, and thus the description thereof is omitted here. Hereinafter, only the shape of the positive electrode terminal (the negative electrode terminal has the same shape) will be described.

FIG. 10 is a diagram illustrating a configuration of a positive electrode terminal 250 as a third embodiment, FIG. 10 (A) is a perspective view, FIG. 10 (B) is a top view, and FIG. 10 (C) is a side view. FIG. 10D is a rear view seen from the outside.
As shown in FIG. 10, in the positive electrode terminal 250, the lead-out portion 255 leading out from the battery has a flat plate shape like a normal battery, but is arranged in the internal space of the battery via a welded portion with an exterior material. In the meantime, an opening (slit) 251 as shown in FIG. 10B is formed. Of the two portions 252 and 253 separated by the slit 251, one portion 252 forms a convex portion projecting upward in the thickness direction of the thin battery, and the other portion 253 is A convex portion protruding in a mountain shape is formed downward in the thickness direction of the thin battery.
In the vicinity of the end of the slit 251, the upward convex portion and the downward convex portion are at the same height as the lead-out portion 255, and are again extended into the internal space of the thin battery as an integral member 254.

In such a positive electrode terminal 250, the distance between the upward convex portion 252 and the downward convex portion 253, that is, the thickness of the positive electrode terminal 250 is substantially equal to the thickness of the power generation element 108 of the thin battery to which the positive terminal 250 is attached. Alternatively, it is formed slightly thicker than the power generation element.
Then, when such a positive electrode terminal 250 and a negative electrode terminal of the same shape are applied to a thin battery, the thickness of the positive electrode terminal 250 is substantially equal to the thickness of the power generation element as described above. The top of the portion 252 is formed in contact with the inner wall of the upper exterior member of the thin battery, and the top of the downward convex portion 253 is in contact with the inner wall of the lower exterior member.
As a result, the position and posture of the positive electrode terminal 250 are maintained by the upper exterior member and the lower exterior member, and the parallelism with the upper and lower surfaces of the power generation element or the upper exterior member and the lower exterior member can be maintained. In addition, the position of the external lead-out portion 255 in the thickness direction of the thin battery can be maintained with high accuracy.

FIG. 11 is a diagram illustrating a configuration of a positive electrode terminal 260 according to the fourth embodiment, FIG. 11 (A) is a perspective view, FIG. 11 (B) is a top view, and FIG. 11 (C) is a side view. FIG. 11D is a rear view seen from the outside.
As shown in FIG. 11, the positive electrode terminal 260 has substantially the same shape as the positive electrode terminal 230 of the thin battery 20 of the second embodiment described above with reference to FIG. That is, the portion 265 led out to the outside has a flat plate shape, but bends upward in the thickness direction of the thin battery from a portion past the welding region with the exterior material from the outside to the inside of the thin battery, It has risen to the height. After reaching a predetermined height position (top 261), it is then bent by approximately 180 degrees, extended downward in the thickness direction of the thin battery, and lowered to a predetermined height position (bottom 262). . Then, in the positive electrode terminal 260 of the fourth embodiment, the lower portion 262 is bent again by approximately 180 degrees and extended upward in the thickness direction of the thin battery, and this time around the center of the thin battery in the thickness direction. The end to the edge of the positive electrode terminal 260 is bent substantially 90 degrees and extends in parallel to the lead-out portion 235 into the internal space 111 of the thin battery.

The thickness of the positive electrode terminal 260 is substantially the same as or slightly larger than the thickness of the power generation element 108 of the thin battery on which the positive electrode terminal 260 is mounted.
When such a positive electrode terminal 260 and a negative electrode terminal of the same shape are applied to a thin battery, the thickness of the positive electrode terminal formed by the wavy shape of the positive electrode terminal 260 is substantially equal to the thickness of the power generation element as described above. Thus, the top portion 261 is formed in contact with the inner wall of the upper exterior member, and the bottom portion 262 is formed in contact with the inner wall of the lower exterior member.
As a result, the position and posture of the positive electrode terminal 260 are maintained by the upper exterior member and the lower exterior member, and the parallelism with the upper and lower surfaces of the power generation element or the upper exterior member and the lower exterior member can be maintained. In addition, the position of the external lead-out portion in the thickness direction of the thin battery can be maintained with high accuracy.

Fifth Embodiment As a fifth embodiment of the present invention, an assembled battery configured by combining the thin battery 10 of the first embodiment will be described with reference to FIGS.
12 is a top perspective view of the assembled battery 50, FIG. 13 is a side perspective view of the assembled battery 50, and FIG. 14 is a cross-sectional view taken along the line CC in FIG.
As shown in FIG. 13, four unit cells (thin batteries) 10 are stacked, sandwiched between restraining plates 51, and fastened and fixed by bolts 52. As shown in FIG. 13, terminals are sequentially connected between adjacent thin batteries 10, and the uppermost positive electrode terminal 210 or negative electrode terminal 220 and the lowermost thin battery 10 negative electrode terminal 220 or positive electrode terminal 210 are assembled batteries. 50 electrode terminals 53 and 54 are led out from the assembled battery 50.

In such an assembled battery, the force applied by the bolt 52 is transmitted to the battery stack through the restraint plate 51, and presses each battery with a predetermined pressure. In the conventional normal thin battery, this pressure is supposed to act on the electrode plate portion (electrode laminate portion) of each battery, so that an appropriate pressure is applied to the electrode portion, It is necessary to manage the tightening pressure by the bolt 52, that is, to manage the torque.
However, in the assembled battery 50 as shown in FIGS. 12 to 14, the pressure by the bolt 52 is applied to the terminal portion and the electrode plate portion, and in particular, the terminal portion of each battery 10 (each By making the thickness of the positive electrode terminal 210 and the negative electrode terminal 220) of the battery 10 slightly larger than the thickness of the electrode portion, most of the pressure is primarily applied to the terminal portion. Therefore, the tightening method and torque management of the bolt 52 are facilitated, and an appropriate load can be easily applied to the load on the electrode plate portion. Specifically, the pressure is increased by tightening the bolt 52, and the restraint plate 51 is bent so that the terminal portion is equal to or slightly less than the thickness of the electrode plate portion. Appropriate load can be applied.

Sixth Embodiment A sixth embodiment of the present invention will be described with reference to FIG.
As for the thin battery used for the thin battery and assembled battery of embodiment mentioned above, as for all, the convex part of a positive electrode terminal and a negative electrode terminal exists in the internal space of a thin battery, and the convex part is the exterior material inner wall of the upper part and the lower part It was the structure which contact | abutted or contacted. However, when there is a member that regulates the thickness in the width direction of the battery, which corresponds to the exterior material, outside the thin battery, the configuration is such that the convex portion comes into contact with or comes into contact with such a member. Also good.
Such a configuration example is shown as a sixth embodiment of the present invention.

FIG. 15 is a diagram showing an assembled battery 60 using such a thin battery.
The assembled battery 60 has a structure in which four unit cells (thin batteries) 30 are stacked with a resin insulating plate 55 sandwiched therebetween, and the whole is further sandwiched with a restraining plate 51 and fixed with bolts 52. Each assembled battery 50 has a positive electrode terminal 270 and a negative electrode terminal 280 together with a power generation element 108 including an electrode plate stacking portion, an upper exterior member 106 and a lower exterior member 107. These four thin batteries 30 are alternately connected in order to form one assembled battery 60.
In the thin battery 30, the positive electrode terminal 270 (the negative electrode terminal 280 has the same shape) has an inner space 111, an upper exterior member 106, and a lower exterior member 107 as shown in FIG. The portion sandwiched between and thermally welded has a simple flat plate configuration as in the conventional thin battery. However, in the portion derived from the thin battery 30, the positive electrode terminal 270 and the negative electrode terminal 280 are formed with protrusions that reach the insulating plates 55 arranged above and below the thin battery 30. The positive electrode terminal 270 and the negative electrode terminal 280 of the thin battery 30 have the same shape as the positive electrode terminal 250 described above with reference to FIG. 10, and a slit is provided in the center, and one of the left and right sides is an upward convex portion. The other is formed as a downward projecting portion. The thicknesses of the positive electrode terminal 270 and the negative electrode terminal 280 defined by the upward convex portion and the downward convex portion are formed to be substantially the same as or slightly thicker than the thickness of the electrode plate laminated portion of the thin battery 30. In addition, the positive electrode terminal 270 and the negative electrode terminal 280 again have a flat plate shape at the tip of the convex portion (outward direction from the battery) and are connected to the terminal of the next thin battery 30.

  In the thin battery 30 including the positive electrode terminal 270 and the negative electrode terminal 280, the convex portions of the positive electrode terminal 270 and the negative electrode terminal 280 are formed to be approximately equal to the thickness of the thin battery 30 as a whole. It is formed in contact with or in contact with insulating plates 55 arranged above and below the thin battery 30. As a result, the positions and postures of the positive electrode terminal 270 and the negative electrode terminal 280 are held by the insulating plate 55, and the parallelism with the electrode plate of the thin battery 30 can be maintained, and the external lead-out portion in the thickness direction of the thin battery Can be maintained with high accuracy.

  In such an assembled battery 30, the force applied by the bolt 52 is applied to the terminal portion and the electrode plate portion via the restraint plate 51. In particular, since the thickness of the positive electrode terminal 270 and the negative electrode terminal 280 of each battery 30 is slightly larger than the thickness of the electrode portion, primarily the pressure is primarily applied to the terminal portion. Become. Therefore, the tightening method and torque management of the bolt 52 are facilitated, and an appropriate load can be easily applied to the load on the electrode plate portion.

  In addition, this Embodiment was described in order to make an understanding of this invention easy, and does not limit this invention at all. Each element disclosed in the present embodiment includes all design changes and equivalents belonging to the technical scope of the present invention, and various suitable modifications are possible.

FIG. 1A is a top view of the thin battery according to the first embodiment of the present invention, and FIG. 1B is a perspective view thereof. 2A is a side view in the longitudinal direction of the thin battery shown in FIG. 1, and FIG. 2B is a perspective view thereof and a cross-sectional view taken along line AA in FIG. . 3A is a side view in the short-side direction of the thin battery shown in FIG. 1, and FIG. 3B is a perspective view thereof and is a cross-sectional view taken along line BB in FIG. is there. 4A is a perspective view of the positive electrode terminal of the thin battery shown in FIG. 1, FIG. 4B is a top view thereof, and FIG. 4C is a side view thereof. 4 (D) is a rear view seen from the outside. FIG. 5 is a diagram illustrating a state where the positive electrode terminal illustrated in FIG. 4 is installed in a thin battery. FIG. 6 (A) is a top view of a thin battery according to the second embodiment of the present invention, and FIG. 6 (B) is a perspective view thereof. 7 is a side perspective view of the thin battery shown in FIG. 6 in the longitudinal direction, and is a cross-sectional view taken along the line AA of FIG. 8 is a side perspective view of the thin battery shown in FIG. 6 in the lateral direction, and is a cross-sectional view taken along line BB of FIG. 6 (A). 9A is a perspective view of the positive electrode terminal of the thin battery shown in FIG. 6, FIG. 9B is a top view thereof, and FIG. 9C is a side view thereof. 9 (D) is a rear view seen from the outside. FIG. 10A is a perspective view of a positive electrode terminal of a thin battery according to a third embodiment of the present invention, FIG. 9B is a top view thereof, and FIG. 9C is a side view thereof. FIG. 9D is a rear view seen from the outside. FIG. 11 (A) is a perspective view of a positive electrode terminal of a thin battery according to a fourth embodiment of the present invention, FIG. 9 (B) is a top view thereof, and FIG. 9 (C) is a side view thereof. FIG. 9D is a rear view seen from the outside. FIG. 12 is a top perspective view of the assembled battery of the fifth embodiment of the present invention. 13 is a side perspective view of the assembled battery shown in FIG. 14 is a cross-sectional view of the assembled battery shown in FIG. 12, and is a cross-sectional view taken along the line CC of FIG. FIG. 15 is a side perspective view of the battery pack according to the sixth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,20,30 ... Thin battery 106 ... Upper exterior member 107 ... Lower exterior member 108 ... Power generation element 111 ... Internal space 210, 230, 250, 260 ... Positive electrode terminal 220, 240 ... Negative electrode terminal 211, 221, 251 ... Slit 212 , 213, 222, 223... Plate-like portion 215, 225, 235, 245, 255, 265... External lead-out portion 231, 252, 261.
232, 253, 262 ... lower bottom (lower convex part)
222, 223 ... plate-like flat plate portions 50, 60 ... assembled battery 51 ... restraint plate 52 ... bolt 53, 54 ... electrode terminal 55 ... insulating plate

Claims (6)

A thin battery in which a power generation element is covered and accommodated by an exterior material, and a terminal connected to the power generation element is derived from a peripheral portion of the exterior material,
The battery is characterized in that the terminal has convex portions formed on both sides in the thickness direction of the thin battery.   The convex portions are formed inside the battery covered with the exterior material, and the convex portions respectively formed on both sides in the thickness direction are formed so as to contact the inner wall of the exterior material. The battery according to claim 1.   The maximum dimension in the thickness direction of the terminal defined by the outermost ends in the terminal thickness direction of the protrusions formed on both sides in the thickness direction is substantially equal to the thickness of the electrode plate laminate of the power generating element. The battery according to claim 2, wherein the battery is slightly larger.   The convex portions are formed outside the battery covered with the exterior material, and the convex portions respectively formed on both sides in the thickness direction are in contact with a predetermined structure disposed outside the battery. The battery according to claim 1, wherein the battery is formed.   The maximum dimension in the thickness direction of the terminal defined by the outermost ends in the terminal thickness direction of the protrusions formed on both sides in the thickness direction is substantially equal to or slightly larger than the thickness of the battery. The battery according to claim 4. A battery laminate in which a plurality of the batteries according to any one of claims 1 to 5 are laminated,
A battery assembly comprising: a holding member that applies a pressure in a thickness direction to the battery stack to integrally fix and hold the battery stack.

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