WO2006038697A1

WO2006038697A1 - Thin battery, assembled cells, and method of producing thin battery

Info

Publication number: WO2006038697A1
Application number: PCT/JP2005/018694
Authority: WO
Inventors: Toshizo Hosoya
Original assignee: Nec Corporation; Fuji Jukogyo Kabushiki Kaisha
Priority date: 2004-10-08
Filing date: 2005-10-11
Publication date: 2006-04-13
Also published as: JP2013145756A; JP6068212B2; JP5290520B2; JPWO2006038697A1

Abstract

A thin battery in which a battery cell is held by a frame body, where production of the thin battery can be simplified and where the outer shape of the frame body is formed with excellent dimensional accuracy. A thin battery (10) has a battery cell (20) in which a power generation element for outputting predetermined electromotive force is enclosed and sealed by a external covering film (4) and in which leads (1, 2) for electrodes electrically connected to the power generation element are extended from the sealed section of the external covering film (4), and the thin battery (10) also has a frame body (30) for holding the battery cell (20). The sealing section of the external covering film (4) is a flat heat seal section formed at an outer peripheral section of the external covering film (4). The frame body (30) is constructed from an insert molded product and is formed so as to hold the surfaces of both sides of the sealing section.

Description

Specification

Thin battery, assembled battery, and method of manufacturing thin battery

Technical field

TECHNICAL FIELD [0001] The present invention relates to a thin battery including a battery cell in which a power generating element that outputs a predetermined electromotive force is hermetically sealed by an envelope having a film force, and a method for manufacturing the same. In particular, the present invention relates to a thin battery in which the battery cell is held by a frame made of a resin material and the like, and a method for manufacturing the same. In addition, the present invention relates to an assembled battery in which two or more of the thin batteries are assembled.

Background art

Conventionally, a thin battery has been used as a power source for an electronic device or the like, or as a power source for driving a motor in an electric vehicle or the like. Thin batteries are available in various sizes depending on the field of use, and various types of batteries are known, including primary and secondary batteries!

FIG. 1 shows a configuration of a thin battery disclosed in, for example, Japanese Patent Laid-Open No. 273642Z99. 1A is a perspective view of a thin battery, and FIG. 1B is a cross-sectional view taken along the line XX of FIG. 1A.

As shown in FIG. 1, a thin battery 110 has a thin power generation element 105 configured to output a predetermined rated voltage, and a frame for holding the power generation element 105 in a sealed state. . The power generation element 105 is configured by a conventionally known technique, and a positive electrode lead 112b and a negative electrode lead 114b are drawn out from the ends thereof. As the frame, an upper synthetic resin frame 118 and a lower synthetic resin frame 119 are provided. Both frame bodies 118 and 119 are stacked one above the other with the leads 112b and 114b sandwiched therebetween. More specifically, both the frame bodies 118 and 119 also have a material force having heat sealability, and are joined to each other by being heated and welded in the manufacturing process to form an integral structure. Note that thin plate-like exterior bodies 116 and 117 are attached to the frames 118 and 119, respectively, so that the power generation element 105 can be hermetically sealed!

[0005] As another type of thin battery, the frame 118, 119 or the like as described above is used to close the power generation element. It is also known that a power generation element is hermetically sealed by a film envelope that is not hermetically sealed. FIG. 2 is a perspective view showing a configuration of a thin battery disclosed in Japanese Patent Application Laid-Open No. 2000-306556.

As shown in FIG. 2, the thin battery 210 includes a battery cell 220 and a frame body 230 that holds the battery cell 220. In the battery cell 220, the power generation element 205 is hermetically sealed using, for example, a laminate film, and leads 201 and 202 are drawn from the outer peripheral portion of the film outer package 204. According to the thin battery 210 of FIG. 2, the use of the film as an outer packaging in this way makes it possible to improve productivity compared to the conventional configuration in which the power generation element is covered with a metal such as stainless steel. Improvements and a small and lightweight battery as a whole have been realized. In addition, since the battery cell 220 is configured to be held by the frame body 230, even when an unexpected impact force is applied to the external force, the impact force is applied to the frame body 230, and the battery cell 220 has It has been added directly. Therefore, the battery cell 220 is not easily damaged, and the reliability of the thin battery 210 as a whole is improved.

Disclosure of the invention

Problems to be solved by the invention

[0007] As described above, in a thin battery having a battery cell in which a power generation element is hermetically sealed with a film envelope, the battery cell is held using a frame surrounding the outer periphery of the battery cell. Is preferred. This is because the reliability of the thin battery against external impact can be improved. In addition, the provision of the frame improves handling and performance during work, and makes it easy to stack even when stacking multiple thin batteries! /, And! /, And other benefits You can also.

[0008] By the way, when manufacturing the thin battery 210 of FIG. 2, the manufacturing method of the Japanese Patent Application Laid-Open No. 2000-306556 is to attach the battery cell 220 to the frame body 230 using an adhesive such as a hot melt material. Is described, but the process is complicated in this method. In addition, in the method using an adhesive, there is a possibility that the adhesive strength between the battery cell 220 and the frame body 230 may vary, and depending on the case, sufficient strength may not be obtained. .

On the other hand, in Japanese Patent Laid-Open No. 273642Z99, as shown in FIG. 1, a power generation element 105 (here, only the leads 112b and 114b are sandwiched) by a pair of synthetic resin frames 118 and 119 A method is shown in which the frames are integrated by heating and then heating. Therefore, if such a method is applied to the frame formation of the battery cell 220 shown in FIG. 2, a thin battery with a more stable holding of the battery cell 220 can be manufactured as compared with the configuration of Japanese Patent Laid-Open No. 2000-306556. It is excluded.

[0010] However, the method disclosed in Japanese Patent Application Laid-Open No. 2000-306556 requires a step of sandwiching the outer periphery of the battery cell with a pair of frames. In addition, a heating process for bonding the pair of frames to each other is necessary, and there is still room for improvement if it has the viewpoint of simplifying the manufacturing process. Furthermore, since the method described in Japanese Patent Application Laid-Open No. 2000-306556 is intended to obtain a final frame by welding a pair of frames to each other, the following problems may be considered. That is, if the heating temperature at the time of melting varies, the amount of the resin melted in each frame also varies. Therefore, in such a method, the thickness accuracy of the finally formed frame is relatively low.

[0011] In a thin battery having a frame as described above, they are often used as an assembled battery by being stacked in the thickness direction of the thin battery. The final shape of the assembled battery can also have a low dimensional accuracy.

[0012] Therefore, an object of the present invention is to simplify the manufacturing process in a thin battery in which battery cells are held by a frame, and the outer shape of the frame is formed with high dimensional accuracy. Another object of the present invention is to provide a thin battery and a manufacturing method thereof. Another object of the present invention is to provide an assembled battery capable of improving the dimensional accuracy of the final shape of the assembled battery in the assembled battery assembled in a state where two or more thin batteries are stacked. It is in this.

Means for solving the problem

In order to achieve the above object, the thin battery of the present invention has a power generation element that outputs a predetermined electromotive force hermetically sealed with a film envelope and is electrically connected to the power generation element. Has a battery cell drawn out from the sealing portion of the film outer casing, and a frame for holding the battery cell, and the sealing portion of the film outer casing is formed of the film outer casing. It is a flat heat seal portion formed on the outer peripheral portion, and the frame body is an insert molded product and is formed so as to sandwich the surfaces on both sides of the sealing portion. [0014] Further, in the method for manufacturing a thin battery according to the present invention, a power generation element that outputs a predetermined electromotive force is hermetically sealed by a film envelope, and an electrode lead electrically connected to the power generation element is provided. A battery cell that is pulled out from the sealing portion of the film envelope and a frame for holding the battery cell, and the sealing portion of the film envelope includes the battery envelope. A flat heat seal portion formed on an outer peripheral portion, wherein the frame body is formed so as to sandwich the surfaces on both sides of the sealing portion. Is formed by an insert molding method.

[0015] According to the thin battery and the manufacturing method thereof of the present invention, the frame body that holds the battery cell is formed by the insert molding method, so the surfaces on both sides of the sealing portion of the film outer package are held. The frame can be formed, for example, by a single injection process. Therefore, the manufacturing process is simplified as compared with the conventional forming method in which the pair of frames are integrated by sandwiching the sealing portion between the pair of frames and then heating. Further, since the outer shape of the frame depends on the mold shape of the mold, the dimensional accuracy of the outer shape is improved as compared with a frame formed by integrating a pair of frames.

[0016] Further, according to the assembled battery of the present invention in which two or more such thin batteries of the present invention are stacked in the thickness direction, one frame of the thin battery of the present invention is provided. Since the external shape of the body is formed with high dimensional accuracy, the dimensional accuracy of the external shape when they are superimposed is improved.

In the thin battery of the present invention, at least one notch is formed in the sealing portion of the film outer package, and the frame has a protrusion that engages with the notch. It may be something. Further, at least one through hole is formed in the sealing portion.

The frame body may have a joint extending through the through hole. Further, the frame body may hold the sealing portion of the film outer package in a folded state.

[0018] The battery cell has first and second leads having different polarities as the electrode lead, and the first lead has substantially the same material force as the second lead. The lead piece may be partially overlapped, and the frame may seal the overlap portion where the first lead and the lead piece are overlapped. In addition, the frame With regard to the outer shape, it is also possible to form a thick portion formed in the frame body with a thickness dimension larger than the thickness dimension of the power generating element.

The invention's effect

[0019] As described above, according to the thin battery and the manufacturing method thereof of the present invention, since the frame body is formed by the insert molding method, the manufacturing process can be simplified and the force of the frame body can be reduced. The outer shape can be formed with high dimensional accuracy. Further, according to the assembled battery of the present invention, the thin batteries of the present invention are stacked and assembled, so that the dimensional accuracy of the outer shape of the final assembled battery can be improved.

Brief Description of Drawings

FIG. 1A is a perspective view showing a configuration of a conventional thin battery.

1B is a cross-sectional view taken along the line XX in FIG. 1A.

FIG. 2 is a perspective view showing a configuration of another conventional thin battery.

FIG. 3 is a perspective view showing a first embodiment of a thin battery of the present invention.

4 is a perspective view showing a battery cell used in the thin battery of FIG. 3 in a single state.

5A is a view showing a cross section of the thin battery in FIG. 3, and is a cross sectional view in the longitudinal direction of the battery cell.

5B is a diagram showing a cross section of the thin battery in FIG. 3, and is a cross sectional view in the short direction of the battery cell.

FIG. 6 is an enlarged view showing, in an enlarged manner, the vicinity of the joint between the heat seal portion of the battery cell and the frame in the thin battery of FIG. 3.

[FIG. 7A] FIG. 7A is a diagram for explaining the rigidity of the frame, and FIG. 7A is a comparative example and shows a cross-sectional view of a configuration in which a pair of frames are overlapped! / Speak.

FIG. 7B shows a cross-sectional view of the frame body in the first embodiment.

FIG. 8 is a perspective view showing a battery cell used in a thin battery according to a second embodiment of the present invention in a single state.

FIG. 9 is a cross-sectional view showing the thin battery according to the second embodiment of the present invention partially cut away. FIG. 10A is a perspective view for explaining the rigidity of the frame as a model. The first fruit The frame in the embodiment is shown.

FIG. 10B is a perspective view for describing the rigidity of the frame as a model, and shows the frame in the second embodiment.

[11] FIG. 11 is a perspective view showing a battery cell used in the thin battery of the third embodiment of the present invention in a single state.

FIG. 12 is a cross sectional view showing a thin battery according to a third embodiment of the present invention, partially cut away.

FIG. 13A is a longitudinal sectional view showing a cross section of a part where a joint exists in a frame.

FIG. 13B is a longitudinal sectional view showing a cross section of a portion of the frame body where no joint portion exists. FIG. 14 is a perspective view showing a battery cell used in the thin battery according to the fourth embodiment of the present invention in a single state.

[15A] FIG. 15C is a view showing a cross section of the frame, and shows a cross-sectional view of a thin battery according to an embodiment of the present invention.

[15B] FIG. 15 is a view showing a cross section of the frame, and shows a cross section of the thin battery according to the first embodiment.

FIG. 16 is a perspective view showing a battery cell used in the thin battery of the fifth embodiment of the present embodiment in a single state.

FIG. 17 is a view showing a cross section of the frame, and in particular, a vertical cross section showing a cross section around the dissimilar metal joint.

Explanation of symbols

1 and 2 leads

la reed piece

4 envelope

4a, 4b, 4c Sealing part

6 Notch

7 Through hole

16 Dissimilar metal joint

10, 11, 12, 13, 14 Thin battery 20, 21, 22, 23, 24 battery cells

30, 31, 32, 33, 34 Frame

31c Projection

32c joint

37 Thick part

38 Thin section

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0023] (First embodiment)

FIG. 3 is a perspective view showing the first embodiment of the thin battery of the present invention. FIG. 4 is a perspective view showing a single battery cell used in the thin battery of FIG. 5 is a cross-sectional view of the thin battery of FIG. 3, FIG. 5A is a cross-sectional view in the longitudinal direction of the battery cell, and FIG. 5B is a cross-sectional view in the short direction of the battery cell. FIG. 6 is an enlarged view showing the vicinity of the joint between the heat seal portion of the battery cell and the frame in the thin battery of FIG.

As shown in FIG. 3, the thin battery 10 according to the first embodiment includes a battery cell 20 and a frame 30 that holds the battery cell 20.

[0025] Like the conventionally known battery cell 20 shown in FIG. 2, the battery cell 20 includes a power generation element (not shown) configured to output a predetermined rated voltage, for example, an envelope 4 having a laminate film force. Is hermetically sealed using Sealing portions 4a and 4b in which the inner surfaces of the film are joined to each other by heat sealing are formed on the outer peripheral portion of the outer package 4. More specifically, the sealing portions 4a and 4b are formed flat and extend outward. Further, for example, as shown in FIG. 6, the sealing portions 4a and 4b are formed so as to be positioned substantially at the center of the battery cell 20 in the thickness direction. This means that in the outer package 4, the upper film and the lower film are formed in the same shape.

[0026] The outer shape of the battery cell 20 when viewed from the upper surface side is not particularly limited, but is formed in a rectangular shape in the present embodiment. As shown in FIG. 4, the short-side sealing part is indicated by reference numeral 4a, and the long-side sealing part is indicated by reference numeral 4b. In addition, the lead 1 for the positive electrode and the lead 2 for the negative electrode, both of which are electrically connected to the power generation element, It is drawn from each of the sealing part 4a on the one side and the sealing part 4a on the other side, but is not particularly limited to this! /.

The frame body 30 is made of a resin material having an insulating property, and is formed in a frame shape so as to surround the entire outer peripheral portion of the battery cell 20. Note that the thickness of each part of the frame 30 may be the same throughout, but in this embodiment, as shown in FIG. 3, a thick part 37 is formed on the short side, A thin portion 38 is formed on the long side.

[0028] As shown in FIG. 6, the thickness dimension t of the thick portion 37 is larger than the thickness dimension t20 of the battery cell 20.

37

It is formed. By the way, in many cases, a plurality of thin batteries 10 are assembled and used as an assembled battery. In general, a plurality of thin batteries 10 are stacked in the thickness direction. In contrast to the assembled form of such an assembled battery, the thick portion 37 of the frame 30 is formed thicker than the battery cell 20 as in the present embodiment. The battery cells 20 are preferable in that they do not contact each other. That is, by making the configuration in which the battery cells 20 do not contact each other, for example, damage to the outer packaging 4 and damage to the power generation element inside the outer packaging 4 can be further suppressed. Further, the advantage that the thick portion 37 is provided is not necessarily limited to the case of manufacturing an assembled battery. That is, since the thickness dimension of the thick part 37 is larger than the thickness dimension of the battery cell 20, the battery cell 20 is difficult to be exposed to external impacts. As a result of providing 37, it is clear that even when the thin battery 10 is handled alone, the battery cell 20 is less likely to be damaged.

[0029] In addition, in terms of improving the stability of holding the battery cell 20 by the frame 30, it is preferable that the entire circumference of the battery cell 20 is held as in the present embodiment, but the present invention is This is not a limitation. In addition, the size of the film outer peripheral area sandwiched between the frame bodies 30 (see the area indicated by the symbol L in FIG. 6) can be appropriately set in consideration of the material of the film, the material of the frame body 30 and the like.ヽヽ.

Next, a method for manufacturing the thin battery 10 configured as described above will be described. First, the battery cell 20 as shown in FIG. 4 is manufactured by a conventionally known manufacturing method. As a conventionally known manufacturing method, for example, a method disclosed in Japanese Patent Application Laid-Open No. 2004-164905 filed earlier by the present applicant can be applied. Next, insert molding is performed on the produced battery cell 20 to form the frame body 30. That is, the battery cell 20 is placed as an insert in a mold provided with a cavity having a shape corresponding to the frame 30, and the frame 30 is formed by injecting molten resin into the cavity in that state. To do. In the insert molding, the resin molded product is formed integrally with the insert product. Therefore, the manufacture of the thin battery 10 of the present embodiment is completed when the injection molding of the frame 30 is completed.

As described above, since the thin battery 10 of the present embodiment forms the frame body 30 by insert molding, the frame body can be basically formed by a single injection process. Therefore, as shown in FIG. 1, the sealing portion is sandwiched between a pair of frame bodies 118 and 119, and then compared with a conventional forming method in which the pair of frame bodies are integrated by calorific heating. The manufacturing process is simplified. Moreover, since the outer shape of the frame body 30 depends on the shape of the cavity in the mold, the frame body 30 can be formed with higher dimensional accuracy than the conventional forming method.

Next, the rigidity of the frame 30 integrally formed by insert molding will be described with reference to FIG. FIG. 7A is a comparative example, and shows a cross-sectional view of a configuration in which a pair of frames 131 and 132 are overlapped. FIG. 7B shows a cross-sectional view of the frame 30 in the present embodiment.

[0034] Since the frame 30 shown in FIG. 7B is integrally formed by insert molding, its cross section is a continuous cross section. When the frame body 30 has a continuous cross section in this way, the deflection amount L1 of the frame body 30 is smaller than the deflection amount L0 of the frame body in FIG. 7A. That is, the frame 30 formed by insert molding has improved rigidity compared to the configuration of FIG. 7A. This means that according to the configuration of the present embodiment, the frame 30 can be downsized as necessary while maintaining the same rigidity.

[0035] As described above, according to the thin battery 10 of the present embodiment, the frame 30 is formed by insert molding, so that the manufacturing process can be simplified as compared with the conventional manufacturing method. Thus, the frame 30 can be formed with high dimensional accuracy. Further, by sealing the portion where the leads 1 and 2 are drawn out of the sealing portion 4a with the frame 30, the above portion of the sealing portion 4a is reinforced, resulting in a thin battery 10. Reliability Will also be improved.

The present invention can be variously modified in addition to the first embodiment described above. Hereinafter, some other embodiments of the thin battery of the present invention will be described with reference to the drawings. In the following description, the description of the same structural part as that of the first embodiment is omitted, and the structural part having the same function is denoted by the same reference numeral in the drawings to be referred to hereinafter.

[0037] (Second Embodiment)

The thin battery of the present invention may use a battery cell as shown in FIG. FIG. 8 is a perspective view showing a single battery cell used in the thin battery according to the second embodiment of the present invention. FIG. 9 is a cross-sectional view showing the thin battery according to the second embodiment of the present invention, partially cut away.

As shown in FIG. 8, a plurality of notches 6 are formed in the sealing portion 4a and the sealing portion 4b of the battery cell 21. The notch 6 is for making the holding of the battery cell by the frame 30 more stable. The shape of the notch 6 is not particularly limited, but is formed in a semicircular shape as an example in the present embodiment. By making the notch 6 semicircular in this way, stress concentration in the notch 6 is relieved, and the possibility of accidentally damaging the envelope 4 when handling the battery cell 21 alone is low. This is preferable.

A thin battery 11 (see FIG. 9) of the present embodiment is manufactured by forming a frame 31 in the battery cell 21 of FIG. 8 using insert molding as in the first embodiment. As a result, the frame body 31 has a protrusion 31c having a shape corresponding to the shape of the notch 6. The outer shape of the frame body 31 is the same as that of the frame body 30 in the first embodiment.

[0040] According to the thin battery 11 configured in this way, in addition to the same operational effects as those of the first embodiment by using insert molding, the cutout portion 6 of the outer packaging body 4 and the projection portion of the frame body 31 Since 31c is engaged, the following effects can be obtained. First, since the notch 6 and the protrusion 31c are engaged, the battery cell 21 can be held more stably by the frame 31. That is, the position of the battery cell 21 is less likely to shift with respect to the frame 31.

[0041] Further, the rigidity of the frame body 31 is improved as compared with the frame body 30 in the first embodiment by the amount of the protrusion 31c. This will be explained with reference to FIG. . The frame 30 is originally formed as an integrally molded product by insert molding as described above, but is modeled as shown in FIG. 10A, and the upper member 30a and the lower member 30b are joined. Assuming that the surfaces S30 are joined together, the rigidity of the entire frame 30 increases as the area of the joining surface S30 increases. In the present embodiment, the area of the joint surface S31 of the frame 31 is larger than the joint surface S30 by the amount of the protrusion 31 formed. As a result, the rigidity of the entire frame 31 is also improved compared to the frame 30. Here, since the outer shape of the frame 31 is the same as that of the frame 30, the size of the thin battery 11 is not increased.

[0042] In the present embodiment, the number of the notches 6 is not particularly limited, but it is sufficient that at least one of the notches 6a, 4b is formed. In order to make the holding of the battery cell 21 more stable, it is preferable to form at least one notch 6 in each of the sealing portions 4a and 4b.

[0043] (Third embodiment)

The thin battery of the present invention may use a battery cell as shown in FIG. FIG. 11 is a perspective view showing a single battery cell used in the thin battery of the third embodiment of the present invention. FIG. 12 is a cross-sectional view showing the thin battery according to the third embodiment of the present invention, partially cut away. FIG. 13 is a longitudinal cross-sectional view showing a cross section of a part of a frame body where a joint is present and a part where no joint is present.

A battery cell 22 shown in FIG. 11 is obtained by forming a plurality of through holes 7 in the sealing portions 4a and 4b of the battery cell 20 of the first embodiment shown in FIG. Then, the thin battery 12 of the present embodiment is manufactured by forming the frame 32 in the battery cell 22 using insert molding. As a result, the frame body 32 has a joint portion 32 c having a shape corresponding to the hole shape of the through hole 7. The outer shape of the frame 32 is the same as that of the frame 30 described above.

[0045] According to the thin battery 12 configured as described above, the through hole 7 and the joint portion 32c are engaged with each other in addition to the same effects as the first embodiment by using the insert molding. The following effects can be obtained. That is, as in the second embodiment, the through hole 7 and the joint portion 32c are engaged with each other, so that the stability of holding the battery cell 22 is achieved. In particular, since the joint portion 32c is formed in a state of penetrating the through hole 7, the effect of the holding stability is first. It is larger than that of the second embodiment. Further, as described with reference to FIG. 10, the rigidity of the entire frame 32 is improved as compared with the frame 30 in the first embodiment by the amount of the joined portion 32c formed. Natsute!

In the present embodiment as well, the number of through holes 7 is not particularly limited, and it is sufficient that at least one of the sealing portions 4a and 4b is formed. Further, the shape and size of the through hole 7 are not particularly limited, but it is preferable that the through hole 7 is opened in a circular shape because stress concentration can be reduced.

[0047] (Fourth embodiment)

The thin battery of the present invention may use a battery cell as shown in FIG. FIG. 14 is a perspective view showing a single battery cell used in the thin battery of the fourth embodiment of the present invention. FIG. 15 is a view showing a cross section of the frame, FIG. 15A shows a cross section of the thin battery of this embodiment, and FIG. 15B shows a cross section of the thin battery of the first embodiment as a comparative example. Yes.

Battery cell 23 shown in FIG. 14 is obtained by bending sealing portion 4b of battery cell 20 of the first embodiment shown in FIG. 4 into sealing portion 4c. Specifically, the sealing portion 4c is formed by bending the side edge on the long side of the battery cell 23, and the bending angle is not particularly limited, but in this embodiment, the main surface of the battery cell 23 is It is bent at an angle of approximately 90 ° to the angle. The thin battery 13 of this embodiment is manufactured by forming a frame 33 in the battery cell 23 by insert molding.

[0049] According to the thin battery 13 configured in this way, in addition to the same operational effects as in the first embodiment by using insert molding, the sealing portion 4c is bent, so that FIG. By bending the sealing portion 4b as shown, the width dimension (dimension in the vertical direction in the figure) of the frame body 33 can be reduced as compared with the configuration. This means that the outer shape of the frame 30 is reduced, which contributes to the downsizing of the thin battery 14. Further, in the configuration in which the battery cell is held by the frame body 33 with the sealing portion 4c bent as in the present embodiment, the stability of holding the battery cell 23 is further improved compared to the configuration of FIG. 15B. It will be. From the above, according to the thin battery 13 of the present embodiment, the holding of the battery cell 23 is further stabilized and the thin battery 13 can be reduced in size as compared with the configuration of the first embodiment. The effect that it can be obtained is obtained.

[0050] In the present embodiment, the sealing portion 4c is formed on both of the two long sides of the battery cell 23, but only one of the sides may be bent. Further, the present invention is not limited to the configuration in which the long side is bent over the whole, and for example, only a part of the long side may be partially bent.

[0051] (Fifth embodiment)

The thin battery of the present invention may use a battery cell as shown in FIG. FIG. 16 is a perspective view showing a battery cell used in the thin battery of the fifth embodiment of the present embodiment in a single state. FIG. 17 is a view showing a cross section of the frame, and in particular, a vertical cross section showing a cross section around the dissimilar metal joint.

The battery cell 24 shown in FIG. 16 has a material for the positive electrode that has substantially the same material force as the lead 2 for the negative electrode of the battery cell 20 of the first embodiment shown in FIG. The lead piece la is joined. The advantage of previously joining the lead piece la to the lead 2 on one side in this way will be briefly described below by taking the battery cell 20 of FIG. 4 as an example.

[0053] In the battery cell 20, the leads 1 and 2 are generally made of different materials such that the lead 1 for the positive electrode is aluminum, for example, while the lead 2 for the negative electrode is copper, for example. Is. When a plurality of battery cells 20 are connected in series to form an assembled battery, after assembling the plurality of battery cells 20, lead 1 of one battery cell 20 and the lead of the other battery cell 20 are assembled. 2 are connected to each other.

By the way, in the configuration in which the leads 1 and 2 that are different metals are connected to each other as described above, the different metals are in contact with each other at the electrical connection portion. It is known that when lead penetrates, the lead member corrodes due to the electrolytic corrosion phenomenon. Therefore, when the battery cells 20 are connected in series as described above, it is necessary to take measures to hermetically seal the electrical connection between the leads with a resin material or the like. However, the process of hermetically sealing the electrical connection between the leads after assembling a plurality of battery cells 20 is complicated.

[0055] Therefore, in order to improve the workability of this hermetic sealing process, the lead piece la is joined in advance in the state of the battery cell 24 alone as shown in FIG. Electrical connection It is preferable to take some measures for hermetic sealing at the connecting portion. Thus, if the lead piece la is joined to the battery cell 24 in advance, the lead 1 and the lead piece la may be connected to each other when the assembled battery is formed. In addition, since the above-described problem of corrosion is unlikely to occur when the same kind of metals are in contact with each other, it is not necessary to hermetically seal the electrical connection portion with a resin material.

The thin battery 14 of the present embodiment is manufactured by forming the frame body 34 by insert molding in the battery cell 24 of FIG. 16 having the above advantages. The frame 34 holds the entire periphery of the battery cell 24, and is formed so as to seal the dissimilar metal joint 16 that is the overlapping portion of the lead 2 and the lead piece la as shown in FIG. !

[0057] According to the thin battery 14 configured as described above, in addition to the same function and effect as in the first embodiment due to the use of insert molding, the frame body 34 is sealed so as to seal the dissimilar metal joint 16. Therefore, the process of forming the frame body 34 and the hermetic sealing process of the dissimilar metal joint 16 can be made common. In addition, the sealing effect of the foreign metal joint 16 by the frame 34 formed by insert molding is superior to that of a method in which, for example, a resin material is applied to a different metal joint and cured. As a result, the thin battery 14 has a high reliability in which corrosion at the dissimilar metal joint 16 hardly occurs.

In this embodiment, the lead piece la is joined to the negative electrode lead 2 side. However, the present invention is not limited to this, and a lead piece having the same material force as the lead 2 is joined to the positive electrode lead 1 side. It may be. The joining of the lead 2 and the lead piece la can be performed by, for example, laser welding, ultrasonic welding or the like. Also, the material of the lead piece la need not be exactly the same as the lead 1 for the positive electrode, and there is no problem of galvanic corrosion.

[0059] As described above, the power described in the embodiments of the present invention by way of examples. The present invention is not limited to these, and various modifications can be made. For example, as described with reference to FIG. 6, the sealing portions 4 a and 4 b of the battery cell 20 were formed at substantially the center in the thickness direction of the battery cell 20. It may be formed on the upper surface side or the lower surface side in the thickness direction. Further, the form of the envelope 4 in the battery cell 20 is not limited to the four-side seal as described above, but may be a three-side seal in which only three sides of the outer peripheral portion are heat-sealed. The power generation elements contained in the battery cell 20 include lithium secondary batteries, nickel metal hydride batteries, nickel cadmium batteries, lithium metal batteries, and lithium batteries. Even a remer battery! / 電池.

Claims

The scope of the claims

[1] A power generation element that outputs a predetermined electromotive force is hermetically sealed by a film envelope, and an electrode lead electrically connected to the power generation element is pulled out from a sealing portion of the film envelope. A battery cell, and a frame for holding the battery cell,

The sealing portion of the film outer envelope is a flat heat seal portion formed on the outer periphery of the film outer envelope,

The frame is an insert-molded product, and is a thin battery formed so as to sandwich both sides of the sealing portion.

[2] In the sealing part of the film outer package, at least one notch is formed, and the frame has a protrusion that engages with the notch. The thin battery as described.

[3] The at least one through hole is formed in the sealing portion of the film outer package, and the frame body has a joint portion extending through the through hole. The thin battery described in 1.

[4] The thin battery according to any one of claims 1 to 3, wherein the frame body holds the sealing portion of the film outer package in a folded state.

[5] The battery cell includes first and second leads having different polarities as the electrode lead, and the first lead has substantially the same material force as the second lead. The lead pieces are partially overlapped,

5. The thin battery according to claim 1, wherein the frame body seals an overlapping portion in which the first lead and the lead piece are overlapped with each other.

[6] The thin battery according to any one of claims 1 to 5, wherein the frame body includes a thick portion formed in a thickness dimension larger than a thickness dimension of the power generation element. .

[7] An assembled battery in which two or more of the thin batteries according to claims 1 to 6 are stacked together in the thickness direction.

[8] A power generation element that outputs a predetermined electromotive force is hermetically sealed by a film envelope, and an electrode lead electrically connected to the power generation element is pulled out from a sealing portion of the film envelope. A battery cell and a frame for holding the battery cell, The sealing portion of the rumm envelope is a flat heat seal portion formed on the outer periphery of the film envelope, and the frame is formed so as to sandwich the surfaces on both sides of the seal portion. A method of manufacturing a thin battery,

A method for manufacturing a thin battery, comprising a step of forming the frame by an insert molding method