JP2007048669A - Battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin-form battery having convex shape on both sides and furnished with an electrode terminal (tab) in the desired position accurately. <P>SOLUTION: The battery is structured so that the rigidity of the peripheral part of one exterior member is made higher than that of the peripheral part of the other exterior member. According to this constitution, deformation of the exterior member generated by a force acting on the inner wall of the battery when its inside is sealed by pinching the electrode terminal in the exterior members while evacuating inside the battery and putting the part in hot fusion attachment can be concentrated in the upper exterior member having a smaller rigidity. As a result, the lower exterior member 107 does not make deformation, and the position of the member 107 relative to a positive electrode terminal 104 and a positive electrode terminal 105 can be maintained in a constant relation. <P>COPYRIGHT: (C)2007,JPO&INPIT

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.

A laminate obtained by laminating a positive electrode plate (positive electrode plate) and a negative electrode plate (negative electrode plate) via a separator and an electrolysis solution are covered with a sheet-like exterior member such as a laminate film and sealed and accommodated. A laminated flat (thin) secondary battery in which an electrode terminal connected to a negative electrode plate is led out from an outer peripheral sticking portion of an exterior member is known (for example, see Patent Document 1). As a general form of such a thin battery, a concave portion (a cup-shaped portion, or a convex portion when viewed from the outside) is formed in each of the two sheet-like exterior members, and the two exterior members are combined to form an outer periphery. There is a bidirectional convex battery in which a laminated body and an electrolyte are sealed and accommodated by thermally welding the parts (see, for example, Patent Document 2). At this time, as an exterior member, a laminate film having a resin layer formed on both front and back surfaces of a metal foil is widely used.
Japanese Patent Laid-Open No. 9-259859 JP 200431270 A

  By the way, in recent years, it has been considered that a plurality of thin batteries as described above are stacked to form an assembled battery and used as a driving power source for driving a traveling motor such as an electric vehicle, a hybrid vehicle, and a fuel cell vehicle. When laminating thin batteries (cells) to form such an assembled battery, if a bi-directionally convex thin battery is used, electrode terminals (tabs) are sandwiched between outer packaging materials and heat sealed to seal the inside of the battery. In some cases, the position of the tab is not stable and the position of the tab may be shifted due to the deformation of the exterior material or the absence of the tab other than the exterior material. In such a state, the position of the terminal shifts, that is, the dimension of the tab from the battery bottom surface varies. As a result, when configuring an assembled battery, when connecting the terminals of cells, it becomes difficult to align, or the accuracy of alignment decreases, the connection resistance increases, the electrode There is a problem that they may be separated or separated from each other.

  This invention is made | formed in view of such a problem, Comprising: It is providing the thin battery in which the electrode terminal (tab) was installed in the desired position with high precision in the thin battery of a bi-directional convex shape.

  In order to solve the above-described problem, a battery according to the present invention combines two exterior members each having a recess, accommodates a power generation element in an internal space formed by the recess, and a peripheral portion of the exterior material. A thin battery in which electrode terminals are led out to the outside, wherein the rigidity of the outer peripheral portion of one of the outer packaging materials is higher than the rigidity of the outer peripheral portion of the other outer packaging material.

  In the battery having such a configuration, when the inside of the battery is hermetically sealed by vacuum-sucking the inside of the battery and sandwiching the electrode terminal between the exterior materials and heat-sealing, a force directed toward the inside of the battery acts on the battery inner wall. In the battery according to the present invention, since the rigidity of the two exterior materials is different, if the exterior material is deformed by the force, the exterior material having the lower rigidity corresponding to the “other exterior material” is deformed. Thus, the positional relationship between the “one exterior material” that does not deform and the electrode terminal is not deformed and is maintained in a certain relationship. The height of the thin battery as a whole is defined by the height of the electrode plate laminate, and is not substantially affected by the force at the time of battery sealing. Therefore, for example, the position of the electrode terminal is maintained at a fixed position with respect to the lowermost surface of the battery, which is also the lower surface of “one exterior material”, and the position is maintained as the position in the width direction of the battery. Is done.

  Suitable methods for increasing the rigidity of “one exterior material” include, for example, increasing the thickness of the exterior material, forming ribs, or forming the electrode terminal along the exterior material to increase the rigidity of the electrode terminal. The method to utilize etc. are mentioned.

  The present invention can provide a thin battery in which electrode terminals (tabs) are installed at desired positions with high accuracy in a thin battery having a convex shape in both directions.

First Embodiment A thin battery according to a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a plan sectional view showing the configuration of the thin battery, and FIG. 2 is a vertical sectional view showing the configuration of the thin battery. 1 is a cross-sectional view taken along line II-II in FIG. 2, and FIG. 2 is a cross-sectional view taken along line II in FIG.
The thin battery 10 is a lithium-based flat laminated type thin secondary battery, and a desired number of thin batteries 10 are stacked as a unit battery to obtain a desired capacity at a desired output voltage. An assembled battery is configured.

  As shown in FIG. 2, the thin battery 10 includes three positive plates 101, five separators 102, three negative plates 103, a positive terminal 104, a negative terminal 105, an upper exterior member 106, a lower exterior member 107, and It has an electrolyte (not shown). In the following description, a laminate of the positive electrode plate 101, the separator 102, and the negative electrode plate 103 is referred to as an electrode group 109, and the electrode group 109 and an electrolyte are also referred to as a power generation element 108.

The positive electrode plate 101 includes a positive electrode side current collector 101a extending to the positive electrode terminal 104 and positive electrode layers 101b and 101c formed on both main surfaces of a part of the positive electrode side current collector 101a. The positive electrode side current collector 101a of the positive electrode plate 101 is formed of an electrochemically stable metal foil such as an aluminum foil, an aluminum alloy foil, a copper foil, or a nickel foil. Further, the positive electrode layers 101b and 101c of the positive electrode plate 101 are made of, for example, a lithium composite oxide such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), or lithium cobaltate (LiCoO ₂ ), chalcogen (S, Se). , Te) A mixture of a positive electrode active material such as a compound, a conductive agent such as carbon black, and an adhesive such as an aqueous dispersion of polytetrafluoroethylene. It is formed by applying to the main surface, drying and rolling.

The negative electrode plate 103 includes a negative electrode side current collector 103a extending to the negative electrode terminal 105, and negative electrode layers 103b and 103c formed on both main surfaces of a part of the negative electrode side current collector 103a, respectively.
The negative electrode side current collector 103a of the negative electrode plate 103 is formed of an electrochemically stable metal foil such as a nickel foil, a copper foil, a stainless steel foil, or an iron foil. Further, the negative electrode layers 103b and 103c of the negative electrode plate 103 are made of, for example, a negative electrode active material that absorbs and releases lithium ions of a positive electrode active material such as amorphous carbon, non-graphitizable carbon, graphitizable carbon, or graphite. An aqueous dispersion of a styrene butadiene rubber resin powder as a precursor material of an organic fired body is mixed, dried, pulverized, and carbonized surfaces carrying carbonized styrene butadiene rubber as a main material. The negative electrode plates 103b and 103c are formed by further mixing a binder such as an acrylic resin emulsion and applying the mixture to both main surfaces of a part of the negative electrode side current collector 103a, followed by drying and rolling. The
When amorphous carbon or non-graphitizable carbon is used as the negative electrode active material, there is no sudden decrease in output, so it is advantageous when used as a power source for electric vehicles.

The separator 102 of the power generation element 108 prevents a short circuit between the positive electrode plate 101 and the negative electrode plate 103 and has a function of holding an electrolyte. The separator 102 is a microporous film made of polyolefin such as polyethylene (PE) or polypropylene (PP), for example. When an overcurrent flows, the pores of the layer are blocked by the heat generation, thereby blocking the current. It also has a function.
The separator 102 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 is used. You can also. Thus, by making the separator 102 into multiple layers, various functions such as an overcurrent prevention function, an electrolyte holding function, and a separator shape maintenance (stiffness improvement) function can be provided.

  As shown in FIG. 2, the above power generation element 108 has positive plates 101 and negative plates 103 alternately stacked with separators 102 interposed therebetween. The three positive plates 101 are respectively connected to the positive terminal 104 made of metal foil through the positive current collector 101a. Similarly, the three negative plates 103 are respectively connected to the negative terminal 105 made of metal foil via the negative current collector 103a.

  The number of the positive electrode plate 101, the separator 102, and the negative electrode plate 103 of the power generation element 108 is not limited to the above number. For example, the power generation element 108 can also be configured with one positive plate 101, three separators 102, and one negative plate 103, and the number of positive plates, separators, and negative plates can be selected as necessary. can do.

  The positive electrode terminal 104 and the negative electrode terminal 105 are not particularly limited as long as they are electrochemically stable metal materials. As the positive electrode terminal 104, for example, an aluminum foil, an aluminum alloy foil, A copper foil, nickel foil, etc. can be mentioned. Moreover, as the negative electrode terminal 105, nickel foil, copper foil, stainless steel foil, iron foil, etc. can be mentioned similarly to the above-mentioned negative electrode side collector 103a, for example.

  In the present embodiment, the metal foils constituting the current collectors 101 a and 103 a of the electrode plates 101 and 103 are extended to the electrode terminals 104 and 105, so that the electrode plates 101 and 103 are directly connected to the electrode terminals 104 and 105. Although connected, the current collectors 101a and 103a of the electrode plates 101 and 103 and the electrode terminals 104 and 105 are connected by a material or component different from the metal foil constituting the current collectors 101a and 103a. Also good.

The power generation elements 108 of these thin batteries 10 are sealed in a state where they are covered with an upper exterior member 106 and a lower exterior member 107 (exterior member). In other words, the power generation element 108 is enclosed in the internal space 111 of the thin battery 10 formed by the upper exterior member 106 and the lower exterior member 107.
In the thin battery 10, as shown in FIG. 2, the upper exterior member 106 and the lower exterior member 107 are respectively formed with concave portions (cup-shaped portion, convex portion when viewed from the outside) 106a and 107a. Then, the upper exterior member 106 and the lower exterior member 107 are aligned so that the recesses face each other, thereby forming an internal space 111 surrounded by the upper exterior member 106 and the lower exterior member 107.

The configuration of the upper exterior member 106 and the lower exterior member 107 will be described with reference to FIG.
FIG. 3 is a diagram for explaining the configuration of the exterior member of the thin battery 10, FIG. 3A is a diagram for explaining the configuration of the upper exterior member 106, and FIG. 3B is the lower exterior member 107. FIG. In FIG. 3, each member is shown by a diagram in which a recess is formed in the same direction for easy comparison.

  As shown in FIG. 3A, the upper exterior member 106 includes a metal foil 106b, an inner resin sheet 106c formed of a resin excellent in electrolyte resistance, and a surface formed of a resin excellent in electrical insulation. It is a laminate film having a three-layer structure with a resin sheet 106d. Further, as shown in FIG. 3B, the lower exterior member 107 is also formed of a metal foil 107b, an inner resin sheet 107c formed of a resin excellent in electrolyte resistance, and a resin excellent in electrical insulation. The laminate film has a three-layer structure with the surface resin sheet 107d.

  Specifically, as the internal metal foil, an aluminum foil is used in the present embodiment. Further, as the surface resin sheet as the outer layer, a polyamide resin such as nylon or a polyester resin is used, and as the inner resin sheet, for example, polyethylene, modified polyethylene, polypropylene, modified polypropylene, or ionomer is used. 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.

As described above, the upper exterior member 106 and the lower exterior member 107 are sheet-like members having the same configuration using the same material, but the thicknesses of the aluminum foil layers 106b and 107b used as the inner layers are between them. It is different. That is, as apparent from comparison between FIGS. 3A and 3B, the thickness of the metal foil layer 107b of the lower exterior member 107 is larger than the thickness of the metal foil layer 106b of the upper exterior member 106. Is clearly thicker. By increasing the thickness of the metal foil layer, the lower exterior member 107 becomes a material having higher rigidity than the upper exterior member 106.
As described above, the thin battery 10 is covered on the outside by the upper exterior member 106 and the lower exterior member 107, but the lower exterior member 107 has a configuration with higher rigidity than the upper exterior member 106. .

Next, the outline of the whole manufacturing method of the thin battery 10 having such a configuration will be described.
First, the power generation element 108 excluding the electrolyte, that is, the positive electrode plate 101, the separator 102, and the negative electrode plate 103 are laminated, and the positive electrode terminal 104 and the negative electrode terminal 105 are welded to the laminated electrode group.
Next, the electrode group 109 in which the positive terminal 104 and the negative terminal 105 are welded is accommodated in the upper exterior member 106 (or lower exterior member 107) formed in a concave shape, and the lower exterior member 107 (or upper exterior member 106) is accommodated in this. ), The power generation element 108, part of the positive electrode terminal 104 and part of the negative electrode terminal 105 are encased in the internal space 111 formed by the upper exterior member 106 and the lower exterior member 107.
Then, the exterior member 106 is injected into the space formed by the exterior members 106 and 107 while injecting a liquid electrolyte having a lithium salt such as lithium perchlorate, lithium borofluoride, or lithium hexafluorophosphate into the organic liquid solvent. , 107 is sucked into a vacuum state, and the outer peripheral edges of the exterior members 106 and 107 are thermally welded and sealed by hot pressing.

  Note that the positive electrode terminal 104 is led out from one end of the sealed exterior members 106 and 107 to the outside, and the negative electrode terminal 105 is led out from the other end to the thickness of the electrode terminals 104 and 105. Only a gap is formed in the welded portion between the upper exterior member 106 and the lower exterior member 107. Therefore, in order to maintain the sealing performance inside the thin battery 10, for example, a seal film made of polyethylene, polypropylene, or the like is interposed in a portion where the electrode terminals 104, 105 and the exterior members 106, 107 are in contact with each other. Is also suitable. It is preferable from the viewpoint of heat weldability that the seal film is made of a resin of the same type as the resin constituting the exterior members 106 and 107 in both the positive electrode terminal 104 and the negative electrode terminal 105.

  In addition, examples of the organic liquid solvent include ester solvents such as propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), and methyl ethyl carbonate. Without being limited thereto, an organic liquid solvent obtained by mixing and preparing an ether solvent such as γ-butylactone (γ-BL) or dietoxyethane (DEE) in an ester solvent may be used.

Thus, in the thin battery 10 of this embodiment, the lower exterior member 107 is made thicker than the upper exterior member 106 to give rigidity.
Therefore, the exterior member that is crushed (the shape is deformed) by the vacuum suction force due to the vacuum suction of the internal space 111 covered with the upper exterior member 106 and the lower exterior member 107 at the time of manufacturing the cell is, for example, a symbol X in FIG. As indicated by the broken lines, the surface is not supported by the electrode group 109 on the upper exterior member 106 side (not in contact with the electrode group 109). Even if the shape of the exterior material of this portion is slightly deformed, there is no influence on the positional relationship between the bottom surface of the lower plate 10 (the lower surface of the lower exterior member 107), which is a normal reference surface, and the positive electrode terminal 104 and the negative electrode terminal 105. . Therefore, in the thin battery 10, the positions of the positive electrode terminal 104 and the negative electrode terminal 105 are accurately arranged at desired positions without being affected by such deformation during manufacturing.

  In addition, in this type of conventional thin battery, since the exterior material is made of a soft material, the rigidity of the battery itself is weak, and depending on the vibration of the vehicle, the tab greatly shakes due to vibration depending on the fixed position of the battery, In some cases, cracks or the like occurred in the battery, affecting the life of the battery. However, in the thin battery 10 according to this embodiment, the rigidity of the main body of the thin battery 10 is increased by increasing the rigidity of the lower exterior member 107. Therefore, it is possible to reduce the amount of deflection of the cell itself due to continued use under conditions with a lot of vibration of the vehicle or the like, and to prevent the thin battery 10 from being cracked. As a result, the life of the thin battery 10 in an environment such as a vehicle can be extended.

  Further, when an assembled battery is configured using such a thin battery 10, the electrode terminals are accurately arranged at desired positions, so that even when they are sequentially connected, they are connected with high accuracy and appropriateness. can do. Accordingly, it is possible to prevent a decrease in the connection resistance of the electrode terminals, peeling due to a connection failure, and the like, and to provide a high-performance and highly durable assembled battery.

Second Embodiment A thin battery according to a second embodiment of the present invention will be described with reference to FIGS.
FIG. 4 is a diagram for explaining the configuration of the thin battery, and is a schematic view of the thin battery seen from the plane direction. FIG. 5 is a vertical sectional view showing the configuration of the thin battery. . 5 is a cross-sectional view taken along the line II of FIG.
The basic configuration of the thin battery 20 of the second embodiment is the same as the thin battery 10 of the first embodiment described above. Hereinafter, about the same structure as the thin battery 10, the same code | symbol is attached | subjected and description is simplified, and only a different structure part from the thin battery 10 is demonstrated in detail.

The thin battery 20 also includes three positive plates 101, five separators 102, and three negative plates 103 in an internal space 111 formed by combining an upper exterior member 106 and a lower exterior member 107 each having a recess. The power generation element 108 having the electrode group 109 and the electrolyte (not shown) are stacked and sealed. In addition, the upper exterior member 106 and the lower exterior member 107 are led out to the outside of the thin battery 20 through the welded portion.
The configurations of the positive electrode plate 101, the negative electrode plate 103, the separator 102, the positive electrode terminal 104, the negative electrode terminal 105, the upper exterior member 106, the lower exterior member 107, and the like are substantially the same as those of the thin battery 10 of the first embodiment described above.

  However, a member having the same thickness as the upper exterior member 106 shown in FIG. 3A is used for the lower exterior member 107 of the thin battery 20 of the second embodiment. That is, in the thin battery 20, the rigidity of the upper exterior member 106 and the lower exterior member 107 is the same, and the rigidity of any member as the exterior material has not already been increased.

In the thin battery 20 according to the second embodiment, in order to increase the rigidity of the lower exterior member 107, the outer periphery of the lower exterior member 107 is bent to form a recess. A rib 201 is formed in the part.
The rib 201 is an outer peripheral portion which is a weak portion of the lower exterior member 107 with respect to the vertical vibration of the thin battery 20, that is, as shown in FIGS. 4 and 5, the positive terminal 104 and the negative terminal of the lower exterior member 107. 105 is formed over a range from the region welded to the upper exterior member 106 through the bent portion and the inclined surface portion for forming the recess to the bottom surface of the lower exterior member 107. Is preferred.
Further, in plan view, for example, as shown in FIG. 4, it is effective to form in the region where the positive electrode terminal 104 and the negative electrode terminal 105 are led out near the outer periphery of the thin battery 20.

The rib 201 may be formed by undulating a part of the lower exterior member 107 in a line shape, or may be formed by adhering a certain bar-shaped member to the surface of the lower exterior member 107 later.
When a part of the lower exterior member 107 is undulated and formed, ribs are formed in any layer of a metal foil (for example, aluminum foil), a surface resin sheet (for example, nylon), or an inner resin sheet (for example, PP). May be.

In the thin battery 20 of the present embodiment, the rigidity of the lower exterior member 107 is increased by adopting such a configuration.
As a result, as with the thin battery 10 of the first embodiment described above, the collapse due to the vacuum suction force is caused by the difference in vacuum suction of the internal space 111 covered with the upper exterior member 106 and the lower exterior member 107 during cell manufacture. It is possible to concentrate on the surface of the upper exterior member 106 that is not in contact with the electrode group 109. As a result, the positions of the positive terminal 104 and the negative terminal 105 are accurately arranged at desired positions without being affected by such deformation.
In addition, by increasing the rigidity of the thin battery 10 itself with such a configuration, the amount of deflection of the cell itself due to continued use under conditions with a lot of vibration of the vehicle or the like can be reduced, and the thin battery 10 can be cracked. Can be prevented. As a result, the life of the thin battery 10 in an environment such as a vehicle can be extended.
Also in this case, since the electrode terminals are accurately arranged at desired positions, when forming an assembled battery, it can be sequentially and accurately connected. Accordingly, it is possible to prevent a decrease in the connection resistance of the electrode terminals, peeling due to a connection failure, and the like, and to provide a high-performance and highly durable assembled battery.

  In addition, the area | region which forms the rib 201 in a plane direction is not restricted to the area | region which fused the positive electrode terminal 104 and the negative electrode terminal 105 as shown in FIG. 4, but as shown in FIG. You may make it form in the whole area along.

Third Embodiment A thin battery according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 7 is a vertical sectional view showing the configuration of the thin battery.
The basic configuration of the thin battery 30 of the third embodiment is also the same as that of the thin battery 10 of the first embodiment described above. Hereinafter, about the same structure as the thin battery 10, the same code | symbol is attached | subjected and description is simplified, and only a different structure part from the thin battery 10 is demonstrated in detail.

The thin battery 30 also includes an electrode group 109 in which a positive electrode plate 101, a separator 102, and a negative electrode plate 103 are stacked in an internal space 111 formed by combining an upper exterior member 106 and a lower exterior member 107, and a power generation element 108 having an electrolyte. In this configuration, the upper exterior member 106 and the lower exterior member 107 are led out of the thin battery 20 through the welded portion.
The configurations of the positive electrode plate 101, the negative electrode plate 103, the separator 102, the upper exterior member 106, the lower exterior member 107, and the like are substantially the same as those of the thin battery 10 of the first embodiment described above, but the thin battery 30 of the third embodiment. For the lower exterior member 107, a member having the same thickness as that of the upper exterior member 106 shown in FIG. That is, like the thin battery 20 of the second embodiment, in the thin battery 30, the rigidity of the upper exterior member 106 and the lower exterior member 107 is the same, and the rigidity of any member has already been increased as the exterior material. Do not mean.

And in the thin battery 30 of 3rd Embodiment, the structure of a positive electrode terminal and a negative electrode terminal differs from the thin battery of 1st Embodiment and 2nd Embodiment which were mentioned above. That is, the positive electrode terminal 204 and the negative electrode terminal 105 of the thin battery 30 have a lower exterior member in the internal space 111 as shown in FIG. It is formed and arranged along 107. That is, the positive electrode terminal 204 and the negative electrode terminal 205 are respectively moved downward along the lower exterior member 107 from the position where they enter the internal space 111 of the thin battery 30 through the welded portion between the upper exterior member 106 and the lower exterior member 107. It is tilted in the direction of the bottom surface, and is bent again when it contacts the bottom surface of the lower exterior member 107, and is shaped so as to extend along the bottom surface of the lower exterior member 107.
As shown in FIG. 7, the leads from the positive electrode plate 101 and the negative electrode plate 103 are connected to the positive electrode terminal 204 and the negative electrode terminal 205 having such a shape as usual.

In the thin battery 30, since the positive electrode terminal 204 and the negative electrode terminal 205 are formed along the lower exterior member 107 in this way, it substantially acts as a reinforcing material for the lower exterior member 107, and as a result, the lower exterior member The rigidity of 107 is increased.
As a result, as with the thin battery 10 of the first embodiment described above, the collapse due to the vacuum suction force is caused by the difference in vacuum suction of the internal space 111 covered with the upper exterior member 106 and the lower exterior member 107 during cell manufacture. It is possible to concentrate on the surface of the upper exterior member 106 that is not in contact with the electrode group 109. As a result, the positions of the positive terminal 204 and the negative terminal 205 are accurately arranged at desired positions without being affected by such deformation.
In addition, by increasing the rigidity of the thin battery 10 itself with such a configuration, the amount of deflection of the cell itself due to continued use under conditions with a lot of vibration of the vehicle or the like can be reduced, and the thin battery 10 can be cracked. Can be prevented. As a result, the life of the thin battery 10 in an environment such as a vehicle can be extended.
Also in this case, since the electrode terminals are accurately arranged at desired positions, when forming an assembled battery, it can be sequentially and accurately connected. Accordingly, it is possible to prevent a decrease in the connection resistance of the electrode terminals, peeling due to a connection failure, and the like, and to provide a high-performance and highly durable assembled battery.

  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.

  For example, in the above-described embodiments, both the upper exterior member 106 and the lower exterior member 107 are configured to increase the rigidity of the lower exterior member 107, but the upper exterior member 106 is configured to increase the rigidity. There may be. In that case, the positional accuracy of the positive electrode terminal 104 and the upper exterior member 106 is defined with high accuracy with respect to the upper exterior member 106. Depending on the mounting form of the thin battery 10 or the like, it may be more convenient to install the thin battery 10 or configure the assembled battery based on the position from the upper surface of the thin battery 10. It may be configured to increase the rigidity of the exterior member 106.

  Further, the method for increasing the rigidity of the exterior member may be a method other than the embodiment described above. For example, the material (metal foil, resin layer, etc.) constituting the exterior member itself may be changed to increase the rigidity. In addition, when the thickness of the exterior member is increased in the first embodiment described above, the thickness of the metal foil layer of the exterior member is increased, but the thickness of the resin layer may be increased. Further, the rigidity may be increased by a method that combines the above-described embodiments.

FIG. 1 is a horizontal sectional view showing the configuration of the thin battery according to the first embodiment of the present invention. FIG. 2 is a vertical cross-sectional view showing the configuration of the thin battery shown in FIG. FIG. 3 is a view for explaining an upper exterior member and a lower exterior member of the thin battery shown in FIG. FIG. 4 is a plan view showing the configuration of the thin battery according to the second embodiment of the present invention. FIG. 5 is a vertical sectional view showing the configuration of the thin battery shown in FIG. 6 is a plan view showing a modification of the thin battery shown in FIG. FIG. 7 is a vertical sectional view showing the configuration of the thin battery according to the third embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 20, 30 ... Thin battery 101 ... Positive electrode plate 102 ... Separator 103 ... Negative electrode plate 104, 204 ... Positive electrode terminal 105, 205 ... Negative electrode terminal 106 ... Upper exterior member 107 ... Lower exterior member 108 ... Power generation element 109 ... Electrode group 201 …rib

Claims (6)

A thin battery in which two exterior members each having a recess formed therein are combined to house a power generation element in an internal space formed by the recess, and an electrode terminal is led out from the peripheral edge of the exterior member,
A battery characterized in that the rigidity of the outer peripheral portion of one of the outer packaging materials is higher than the rigidity of the outer peripheral portion of the other outer packaging material.   2. The battery according to claim 1, wherein the one exterior material is an exterior material disposed on a lower side in a vertical direction when the battery is mounted.   By making the thickness of at least the outer peripheral portion of the one exterior material thicker than the thickness of the outer peripheral portion of the other exterior material, the rigidity of the outer peripheral portion of the one exterior material can be increased. The battery according to claim 1, wherein the battery has a higher rigidity than the outer peripheral portion.   The exterior material is an exterior material manufactured by forming a resin layer on both front and back surfaces of a metal foil, and the one exterior material has at least the thickness of the metal foil in the outer peripheral portion, and the other exterior material. The rigidity of the said outer peripheral part of said one exterior material is made higher than the rigidity of the said outer peripheral part of said other exterior material by making it thicker than the thickness of the said metal foil of Claim 3. Battery.   By forming a rib on at least the outer peripheral portion of the one exterior material, the rigidity of the outer peripheral portion of the one exterior material is made higher than the rigidity of the outer peripheral portion of the other exterior material. The battery according to claim 1 or 2.   By forming the electrode terminal in the internal space along the inner wall of the one exterior material, the rigidity of the outer peripheral portion of the one exterior material is made to be greater than the rigidity of the outer peripheral portion of the other exterior material. The battery according to claim 1, wherein the battery is raised.

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