JP4168592B2 - Secondary battery and method for manufacturing secondary battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
According to the present invention, an electrode body in which lead portions extending from a positive electrode and a negative electrode to predetermined positions are formed, and an external terminal that accommodates the electrode body and can be electrically connected to the lead portion are integrally formed. The present invention relates to a secondary battery having a sealed container.
[0002]
[Prior art]
Conventionally, as this type of secondary battery, an electrode body formed by laminating or winding a positive electrode and a negative electrode is used together with a lead portion (current collector portion) extending outward from the positive electrode and the negative electrode, respectively. There have been proposed ones in which terminals are formed so as to be housed inside and connected to the lead portions by welding or the like and exposed to the outside of the container (for example, Japanese Patent Laid-Open Nos. 9-147830 and 10-270048). Such).
[0003]
[Problems to be solved by the invention]
However, in such a secondary battery, the performance may not be sufficiently exhibited or the structure may be complicated. In conventional secondary batteries, the terminal must be shaped to connect the lead inside the container and the outside of the container (the part that becomes the external terminal), so the internal structure of the battery is complex depending on the extension position of the lead. Or the connection resistance from the lead part to the external terminal increases, and the battery performance decreases. Further, if the battery has a complicated structure, the manufacturing process of the secondary battery may become complicated, or the secondary battery itself may become large. Such problems are greatly highlighted when considering the reduction in size and performance of secondary batteries.
[0004]
One object of the secondary battery of the present invention is to have a simple configuration while maintaining battery performance. Another object of the method for manufacturing a secondary battery of the present invention is to provide a method for manufacturing a secondary battery having a simple configuration while maintaining battery performance.
[0005]
[Means for solving the problems and their functions and effects]
The secondary battery and the method for manufacturing the secondary battery of the present invention employ the following means in order to achieve at least a part of the above object.
[0006]
The secondary battery of the present invention is
A secondary battery comprising: an electrode body in which a lead portion of a positive electrode and a negative electrode is formed; and a sealed container in which an external terminal that houses the electrode body and can be electrically connected to the lead portion is integrally formed. ,
In a state in which pre-Symbol electrode body is accommodated by the closed container, the external terminal is a coatable shape fitted to the lead portion, the lead portion, the positive electrode as fit inserted into the external terminal the a collector portion of the negative electrode which was the focused respectively, characterized Rukoto connected the direct and the external terminal.
[0007]
According to the secondary battery of the present invention, since the lead portion of the electrode body Ru fitted to the external terminals which are integrally formed on the closed container can be a simple structure while maintaining cell performance. Here, “the external terminal is integrally formed” means that the closed container is completely formed of the same material as the external terminal, and that the external terminal is assembled by adhesion or injection molding in the manufacturing process of the closed container. The one formed integrally is also included.
[0008]
In such a secondary battery of the present invention, the sealed container is formed of two members each formed of an electrically conductive member, and each of the external terminals that can cover the lead portion is formed. Further, it can be joined by caulking through an electrically insulating member in a state where the electrode body is housed.
[0009]
The external terminal may be connected to the lead portion by pressure bonding. In this way, the influence on the electrode body can be reduced when the lead portion is connected to the external terminal.
[0010]
The method for producing the secondary battery of the present invention includes:
And an electrode forming step of forming an electrode body having a lead portion of the positive and negative electrodes,
A shape that can seal the electrode assembly by joining together, an electrically conductive two sealing members, each having an external terminal for said leading portion and electrically connected to the position fitted to the lead portion A sealing member forming step formed by the members of
A lead part forming step of focusing the current collecting portions of the positive electrode and the negative electrode so as to be fitted into the external terminal, and forming the lead part directly connected to the external terminal;
A housing step of housing the electrode body in the two formed sealing members;
And a bonding step of bonding the external terminal to the lead portion and bonding the two sealing members via an electrically insulating member.
[0011]
According to the manufacturing method of the secondary battery of the present invention, producing a secondary battery having a simple configuration because the lead portion of the electrode body Ru fitted to an external terminal which is integrally formed in a sealed container, while maintaining the performance can do.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described using examples. FIG. 1 is a block diagram showing an outline of the configuration of a secondary battery 20 according to an embodiment of the present invention, and FIG. is there. Example of the secondary battery 20 is, for example, is configured as a lithium ion battery or a nickel hydrogen battery, as shown, the positive electrode side lead 34 and the negative electrode side of the current collecting portion of the positive electrode 31 and negative electrode 32 An electrode body 30 having a lead portion 36; a battery case 28 in which the electrode body 30 is housed and the negative electrode side terminal portion 26 electrically connected to the negative electrode side lead portion 36 is formed; and a lid of the battery case 28 And a case lid 24 formed with a positive terminal portion 22 that is electrically connected to the positive lead portion 34 when assembled to the battery case 28. The negative electrode side terminal portion 26 formed on the battery case 28 and the positive electrode side terminal portion 22 formed on the case lid 24 function as external terminals for exchanging electric power with electric devices and the like.
[0013]
The electrode body 30 is formed by a positive electrode 31 and a negative electrode 32 coming into contact with each other through a separator 33 and wound. The positive electrode side lead portion 34 of the current collecting part component of the positive electrode 31 is formed by using the uncoated portion of the positive electrode active material into a strip-shaped metal plate with a base electrode (upper part of FIG. 2). On the other hand, the negative electrode side lead section 36 of the current collecting part component of the negative electrode 32, opposite to the positive electrode side lead portion 34 of the positive electrode 31 direction of the negative electrode active material to the metal plate provided on the (lower part of FIG. 2) It is formed using an uncoated part. Of course, in this embodiment, the uncoated portions of the active material are formed as the positive electrode side lead portion 34 and the negative electrode side lead portion 36, but a conductive material is separately bonded to the positive electrode 31 and the negative electrode 32. Then, this may be formed as a lead portion.
[0014]
The battery case 28 is formed of a material having excellent conductivity (for example, nickel-plated iron material, aluminum, stainless steel, etc.). In the lower part of the battery case 28 in FIG. 2, a negative electrode side terminal portion 26 that can be covered with a negative electrode side lead portion 36 is formed. The negative electrode side terminal portion 26 is electrically connected by crimping in a state where the negative electrode side lead portion 36 is inserted.
[0015]
Similarly to the battery case 28, the case lid 24 is formed of a material having excellent conductivity, and the electrode body 30 can be covered and sealed in a state of being assembled and joined to the battery case 28. The case lid 24 is formed with a positive terminal portion 22 that can be covered by inserting a positive lead portion 34 at the center thereof. The positive terminal portion 22 is electrically connected by crimping with the positive lead portion 34 inserted. The case lid 24 and the battery case 28 are joined by a joining portion 42 via an insulating material (for example, resin), and electrical insulation between the positive terminal portion 22 and the negative terminal portion 26 is ensured. is doing.
[0016]
A process for manufacturing the secondary battery 20 configured as described above will be described. FIG. 3 is an explanatory diagram for explaining the production of the secondary battery 20 of the embodiment. Consider a case where a spiral secondary battery in which a positive electrode terminal and a negative electrode terminal are formed on opposite surfaces as the secondary battery 20 is manufactured. As shown in the figure, the secondary battery 20 first has a positive electrode active portion so that an uncoated portion (current collecting portion) is formed at one end portion in the longitudinal direction with respect to two strip-shaped metal plates having the same shape. The positive electrode 31 and the negative electrode 32 are formed by applying the material and the negative electrode active material in the same shape (rectangular shape), and the non-coated portions (current collecting portions) protrude in directions facing each other. And the negative electrode 32 are brought into contact with each other through the separator 33 and wound to form the electrode body 30 (FIG. 3A). Next, the current collecting part (uncoated part of the active material) of the electrode body 30 is pressed and the unnecessary part is cut away to form the positive electrode side lead part 34 and the negative electrode side lead part 36 (FIG. 3B, ( c)). Thus, the positive-side leads 34 and the negative electrode side lead section 36 will be fitted in a position that is directly connected to the external terminal of the secondary battery 20. Next, the battery case 28 and the case lid 24 are formed of a material having excellent conductivity such as iron or nickel as a container for covering and sealing the electrode body 30. At this time, the battery case 28 has the negative electrode side terminal portion 26 fitted to the negative electrode side lead portion 36, and the case lid 24 has the positive electrode side terminal portion 22 fitted to the positive electrode side lead portion 34, respectively. It is formed by drawing or the like. Then, the case cover 24 and the positive terminal 22 and the positive-side lead 34 is attached at a position fitted, electrically connected by crimping the positive terminal 22 and the positive-side lead section 34 (FIG. 3 (D)). Battery with Subsequently, mounted at a position where the battery case 28 and the negative terminal 26 and the negative electrode side lead portion 36 is fitted, are electrically connected by crimping the negative electrode terminal part 26 and the negative electrode side lead section 36 The case 28 and the case lid 24 are joined by caulking through an insulating material (for example, resin) (FIG. 3E), and the secondary battery 20 is completed.
[0017]
According to the secondary battery 20 of the present invention described above, the positive electrode side lead portion 34 and the negative electrode side lead portion 36 of the electrode body 30 are integrally formed on the battery case 28 and the case lid 24 that are containers of the electrode body 30. by fitted respectively to the positive terminal 22 and the negative electrode terminal part 26 as an external terminal, it is possible to reduce the number of parts can be a secondary battery having the simple configuration while maintaining performance. As a result, the secondary battery can be reduced in weight and size. Moreover, since the connection between the positive electrode side terminal portion 22 and the positive electrode side lead portion 34 and the connection between the negative electrode side terminal portion 26 and the negative electrode side lead portion 36 are performed by pressure bonding, heat generation at the time of connection between the two can be suppressed, Thus, the influence on the electrode body 30 can be further reduced.
[0018]
In the secondary battery 20 of the example, the positive electrode side terminal portion 22 and the positive electrode side lead portion 34 are electrically connected and the negative electrode side terminal portion 26 and the negative electrode side lead portion 36 are electrically connected by pressure bonding. Further, laser welding with relatively little heat generation may be used in combination as appropriate. Moreover, you may use another connection method (For example, the connection by the assembly | attachment of a volt | bolt etc.) within the range which does not affect the performance of the secondary battery 20. FIG.
[0019]
In the secondary battery 20 of the embodiment, the case lid 24 and the battery case 28 are joined by caulking through an insulating member, but the case lid 24 and the battery case 28 are joined via an insulating member. It is good also as what adheres.
[0020]
Furthermore, in the secondary battery 20 of the example, the case lid 24 and the battery case 28 as a battery container are formed of a material having excellent electrical conductivity, and both are bonded via an insulating material. If the positive electrode side terminal portion 22 and the negative electrode side terminal portion 26 are formed of a material having excellent electrical conductivity and the insulation of both can be secured, the other part of the container is formed of an insulating material such as a resin. Also good. In this case, the case lid 24 and the battery case 28 are, for example, a positive electrode side terminal portion 22 and a negative electrode side terminal that are previously formed of a material having excellent electrical conductivity in a mold that forms the case lid 24 and the battery case 28 by injection. It can be manufactured by fixing the part 26 to a predetermined part and pouring the resin into the mold in this state. Alternatively, the case lid 24 and the battery case 28 may be formed by bonding the positive electrode side terminal portion 22 and the negative electrode side terminal portion 26.
[0021]
In the secondary battery 20 of the embodiment, the positive electrode 31 and the negative electrode 32 are wound. However, the positive battery 31 and the negative electrode 32 may be stacked. FIG. 4 is an exploded view showing a schematic configuration of a secondary battery 120 having an electrode body 130 in which a positive electrode and a negative electrode are stacked on each other. 4, the electrode body 130 includes a positive-side lead section 134 as a current collector unit amount of the positive electrode, as a current collector unit amount of the negative electrode at different sites flush with the surface of the positive-side lead section 134 is formed and a negative-side lead section 136 of. A box-shaped battery case 128 that houses the electrode body 130 is formed of resin. Resin case lid 124 to form the lid of the battery case 128, at positions electrically to fitted to the positive electrode side lead 134 and the negative electrode side lead portion 136 when assembled in a battery case 128 accommodating the electrode body 130 The positive electrode side terminal portion 122 and the negative electrode side terminal portion 126 formed of a material having excellent conductivity are formed so as to be fitted. The positive lead portion 134 and the negative lead portion 136 can be formed on the case lid 124 by the method described above. Note that the case lid 124 and the battery case 128 are bonded together by, for example, heat welding, and the electrode body 130 is hermetically stored.
[0022]
In the secondary battery 20 of the embodiment, the sealed container for housing the electrode body 30 is formed by the two members of the battery case 28 and the case lid 24. However, the sealed battery is sealed by one or more members. It is good also as what forms a container.
[0023]
Further, in the battery 20 of the example, the positive electrode side terminal portion 22 is formed on the case lid 24 and the negative electrode side terminal portion 26 is formed on the battery case 28. However, the negative electrode side terminal portion is formed on the case lid, The positive electrode side terminal portion may be formed on the battery case. Moreover, as long as insulation is ensured, it is good also as what forms a positive electrode side terminal part and a negative electrode side terminal part in one of a battery case or a case cover.
[0024]
The embodiments of the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments and can be implemented in various forms without departing from the gist of the present invention. Of course you get.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an outline of a configuration of a secondary battery 20 according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the AA cross section in FIG. 1 of the secondary battery 20 of the example.
FIG. 3 is an explanatory diagram illustrating a state of manufacturing the secondary battery 20 of the example.
FIG. 4 is an exploded view showing an outline of the configuration of a secondary battery 120 having an electrode body 130 in which a positive electrode and a negative electrode are stacked on each other.
[Explanation of symbols]
20, 120 Secondary battery, 22, 122 Positive terminal, 26, 126 Negative terminal, 24, 124 Case lid, 28, 128 Battery case, 30, 130 electrode body, 31 Positive electrode, 32 Negative electrode, 33 Separator, 34, 134 Positive side lead part, 36, 136 Negative side lead part, 42 Joining part.

Claims (4)

A secondary battery comprising: an electrode body in which a lead portion of a positive electrode and a negative electrode is formed; and a sealed container in which an external terminal that houses the electrode body and can be electrically connected to the lead portion is integrally formed. ,
In a state in which pre-Symbol electrode body is accommodated by the closed container, the external terminal is a coatable shape fitted to the lead portion, the lead portion, the positive electrode as fit inserted into the external terminal the negative electrode of the current collecting part be one that is focused respectively, secondary batteries, characterized Rukoto connected the direct and the external terminal. The secondary battery according to claim 1,
The sealed container is formed of two members each formed of a member having electrical conductivity, and each of the external terminals capable of covering the lead portion is formed.
The secondary battery, wherein the two members are joined by caulking through an electrically insulating member in a state where the electrode body is accommodated. The secondary battery according to claim 1 or 2,
The secondary battery, wherein the external terminal is connected to the lead portion by pressure bonding. An electrode forming step of forming an electrode body having a lead portion of the positive and negative electrodes,
A shape that can seal the electrode assembly by joining together, an electrically conductive two sealing members, each having an external terminal for said leading portion and electrically connected to the position fitted to the lead portion A sealing member forming step formed by the members of
A lead part forming step of focusing the current collecting portions of the positive electrode and the negative electrode so as to be fitted into the external terminal, and forming the lead part directly connected to the external terminal;
A housing step of housing the electrode body in the two formed sealing members;
And a joining step of joining the external terminal to the lead portion and joining the two sealing members via an electrically insulating member.

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