JP4266097B2 - battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery having an improved electrode lead structure.
[0002]
[Prior art]
Conventionally, a lithium ion battery has been used as a battery in which a battery body in which a power generation element is housed in a battery case is housed in a resin case or cover in which a protective element or the like is disposed.
[0003]
[Problems to be solved by the invention]
In recent years, the market price of the lithium ion battery has fallen, and in order to meet the market price, there is an urgent need to reduce the size and cost of the battery. However, the conventional structure in which the battery main body is housed in a resin case or cover has a limit in reducing the size of the battery.
[0004]
The present invention has been completed based on the above circumstances, and an object thereof is to reduce the size of a battery.
[0005]
[Means for Solving the Problems]
As a means for achieving the above object, the invention of claim 1 is a metal battery case that houses a power generation element, and closes an opening of the battery case and includes a positive electrode and a negative electrode of the power generation element. A first metal lid electrically connected to one of the electrodes, an extraction electrode electrically insulated from the first lid and connected to the other of the positive electrode and the negative electrode, A second lid made of resin provided on the first lid, and the second lid is integrally provided with a metal insert part by insert molding, and the insert part is provided with the first lid. The second lid is fixed to the first lid by being fixed to the lid, and the second lid has a pair of external connection terminals electrically connected to the insert part and the extraction electrode, respectively. It is characterized by being provided .
[0006]
According to a second aspect of the present invention, there is provided a metal battery case having a flat rectangular shape that accommodates the power generation element therein, an opening of the battery case that is electrically connected to one of the positive electrode and the negative electrode of the power generation element. A metal first lid provided with a pair of connection projections located near both ends and electrically insulated from the battery lid, the other of the positive electrode and the negative electrode An extraction electrode connected to the electrode; and a second lid in which metal first and second insert parts are integrally provided by insert molding and are overlapped with the first lid. The first and second insert parts are fixed to the first lid by being fixed to the connection protrusion of the first lid, and a pair of external connection terminals is provided on the second lid. And one of the external connection terminals is the first insert part It is connected, and the other external connection terminals, characterized in that it is connected to the lead electrode via a circuit element.
[0007]
[Action and effect of the invention]
<Invention of Claim 1>
According to the first aspect of the present invention, since the components for electrically connecting the positive and negative electrodes of the power generation element to the external connection terminal can be disposed in the second lid, the resin case covering the entire battery Or a cover becomes unnecessary. As a result, the battery can be reduced in size.
[0008]
<Invention of Claim 2>
According to the invention of claim 2, since the second lid has a built-in circuit element, it is electrically necessary not only for the part that electrically connects the positive electrode and the negative electrode to the external connection terminal but also for the battery. Since all of these elements can be arranged in the second lid, the battery can be further reduced in size compared with the invention of claim 1.
[0009]
In addition, the first lid and the first lid are fixed by fixing a pair of connection projections provided near both ends of the first lid and a metal insert part insert-molded on the second lid. 2 lids can be firmly fixed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[0011]
An embodiment of the present invention will be described with reference to FIGS. The battery 1 of the present embodiment is a non-aqueous electrolyte secondary battery for a mobile phone configured by attaching a square resin lid 3 (corresponding to a second lid) to one side of a flat rectangular secondary battery body 2. is there.
[0012]
First, the secondary battery body 2 will be described. The secondary battery body 2 is manufactured by enclosing a power generation element 5 and an electrolyte (not shown) in a metal battery case 4. Although the power generation element 5 is not shown in detail, a strip-like negative electrode and a positive electrode are wound through a separator to form a flat spiral shape. The battery case 4 is formed, for example, by press-molding an aluminum plate, and its opening is closed by a battery lid 6 (corresponding to a first lid), which is also made of aluminum and laser-welded. An aluminum connection piece 7 is fixed to the inner surface of the battery lid 6, and the connection piece 7 is electrically connected to the positive electrode of the power generation element 5 via a positive electrode lead (not shown). .
[0013]
On the other hand, the battery cover 6 is provided with a negative electrode internal terminal 8 (corresponding to an extraction electrode). The negative electrode internal terminal 8 is formed by inserting a plastic gasket 10 into a through hole 9 formed in the battery lid 6 and penetrating the gasket 10 with a shaft portion 8A provided on the lower surface of the negative electrode internal terminal 8. Further, the negative electrode insulating plate 11 and the negative electrode connecting piece 12 are fitted into the shaft portion 8A from the lower surface side of the battery lid 6, and the shaft portion 8A is caulked to be fixed. Thereby, the negative electrode internal terminal 8 is in an insulated state from the battery lid 6.
[0014]
Connection protrusions 16 are formed by press molding at positions near the left and right ends of the battery lid 6, and a safety valve 13 is provided at a position near the center. The safety valve 13 is configured by closing an elliptical through-hole 15 provided in the battery lid 6 with, for example, an aluminum thin film 14.
[0015]
Next, the resin lid 3 will be described. The resin lid 3 has an elongated container shape and substantially the same shape as the upper surface of the secondary battery main body 2, and the upper surface of the secondary battery main body 2 with the lower surface of the opening being on the secondary battery main body 2 side. It is attached to cover. Two through holes 17 and 18 penetrating vertically are formed at positions near the left and right ends of the resin lid 3, and two shallow recesses 19 and 20 are provided near the center of the upper surface.
[0016]
Three metal plates 21, 22, 23 corresponding to the first to third insert parts are embedded in the resin lid 3 by insert molding. Among these, the metal plate 21 (first insert part) is a resin lid. 3 is partly exposed in the through-hole 17 and one end extends toward the center and is exposed in the recess 19 where gold plating 24 is applied to the external connection terminal on the positive electrode side. 25 is configured.
[0017]
On the other hand, the metal plate 22 (second insert part) is located near the right end of the resin lid 3, a part of the metal plate 22 is exposed in the through hole 18, and the remaining part is embedded in the resin lid 3. The metal plates 21 and 22 are made of a clad material in which a nickel base is covered with aluminum, and are disposed in the resin lid 3 so that the surface on the battery body 2 side is aluminum.
[0018]
In addition, a part of the metal plate 23 (third insert part) is exposed in the recess 20, and a gold plating 26 is applied thereto to form an external connection terminal 27 on the negative electrode side. One end of the metal plate 23 is bent in an L shape and protrudes into a recess 28 formed on the lower surface of the resin lid 3. A thermal fuse 30 and a PTC 32 corresponding to circuit elements are accommodated in the recess 28, one nickel lead 29 of the thermal fuse 30 is connected to the metal plate 23, and the other nickel lead 31 is connected to the upper surface of the PTC 32. ing. A nickel lead 33 is led out from the lower surface of the PTC 32. The resin lid 3 is provided with a gas vent hole (not shown) on the side of the safety valve 13.
[0019]
The above-described resin lid 3 is fixed to the battery body 2 as follows. First, the end of the nickel lead 33 of the PTC 32 is welded to the negative electrode internal terminal 8 of the battery body 2. Thereafter, the two through holes 17 and 18 of the resin lid 3 are fitted into the connection protrusions 16 and 16 of the battery body 2, and the metal plates 21 and 22 of the resin lid 3 are pressed against the connection protrusions 16 and 16. The metal plates 21 and 22 are welded to the connection protrusions 16 and 16 by irradiating, for example, a laser beam from a laser welding machine from above the through holes 17 and 18. Thereby, the resin lid 3 is fixed to the battery body 2 (see FIG. 3). An insulating plate 34 is affixed to the upper surface of the battery lid 6 so that the battery lid 6 is electrically insulated from the nickel lead 33 and the like.
[0020]
According to the present embodiment, since the resin lid 3 provided with the external connection terminals 25 and 27 is attached to the battery body 2, a conventional resin case covering the battery body 2 becomes unnecessary. Therefore, the entire battery can be reduced in size. Moreover, when the resin lid 3 is fixed to the battery body 2, three metal plates 21, 22, and 23 are insert-molded into the resin lid 3, and these metal plates 21 and 22 are connected to a pair of connection protrusions of the battery lid 6. Since the resin lid 3 is firmly fixed by welding, the electrical connection with the metal plate 21 connected to the external connection terminal 25 on the positive electrode side is completed at the same time. Therefore, it is not necessary to connect the external connection terminal 25 and the battery body 2 separately from the fixing of the resin lid 3, and the number of manufacturing steps can be reduced. Furthermore, since the metal lids 21 to 23 are inserted into the resin lid 3, the rigidity of the resin lid 3 itself is increased, and this deforms even when a large force is applied to the resin lid 3 from the outside. Can be reliably prevented from falling off.
[0021]
By the way, since this type of small battery is used as a power source for a mobile phone, it may be removed from the phone body and carried in a pocket, for example. In such a case, if a key holder with a metal chain is also put in the pocket, the chain may come into contact with the external connection terminal of the battery and cause a short circuit. Even if a short-circuit occurs as described above, the built-in circuit element is activated and short-circuited in a conventional battery in which only the positive and negative external connection terminals are exposed by housing the battery body in a resin case. Since the current is cut off, there are few problems.
[0022]
However, in the structure in which the metal battery case is exposed and the positive and negative external connection terminals are also exposed as in this embodiment, one of the chains is in contact with the battery case and the other is connected to the circuit element. There is a possibility that the short-circuit current cannot be cut off when touching an external connection terminal that is not present.
[0023]
In view of this point, in the present embodiment, since the thermal fuse 30 and the PTC 32 are provided in the external connection terminal 27 on the negative electrode side that has a polarity opposite to the polarity (positive electrode) of the battery case 4 in particular, Even if the chain short-circuits between the outer surface of the battery case 4 and the external connection terminal 27 on the negative electrode side, the short-circuit current can be reliably interrupted by the PTC 32. Even if the chain is in contact between the outer surface of the battery case 4 and the external connection terminal 25 on the positive electrode side, since these are of the same polarity, no short circuit current flows.
[0024]
<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
[0025]
(1) In the above-described embodiment, the connection protrusion 16 and the metal plates 21 and 22 are fixed by laser welding. However, the present invention is not limited to this, and methods such as resistance welding, ultrasonic welding, and brazing can be used. . Moreover, it can fix by caulking as shown in FIG. In this case, as shown in FIG. 4A, a caulking cylinder 40 is projected from the upper surface of the connection projection 16 projecting from the battery lid 6, and the caulking cylinder 40 is inserted through the metal plate 41. For this purpose, a hole 42 is formed.
Then, as shown in FIG. 4B, the metal plate 41 may be fixed by crushing the crimping tube 40 and deforming it into a rivet shape. Further, as shown in FIG. 4C, the metal plate 41 may be fixed by expanding and deforming the crimping tube 40 outward.
When the metal plate 41 is fixed by such caulking, the portion to be caulked is not a solid part such as an ordinary rivet, but the hollow caulking cylinder 40 shown in FIG. It is preferable for reducing the caulking stress. Further, from the viewpoint of stabilizing the contact resistance between the caulking cylinder 40 and the metal plate 41, the contact surface of the connection protrusion 16 that contacts the metal plate 41 is roughened, or the receptacle that partially bulges on the contact surface. It is preferable to form a protrusion.
(2) In the above-described embodiment, the thermal fuse 30 and the PTC 32 are used as circuit elements. However, the present invention is not limited to this, and a thermal protector, an identification resistor, an NTC, a thermistor, or the like may be used.
(3) In the above-described embodiment, the battery case 4 has the same polarity as the positive electrode. However, the present invention is not limited to this, and the battery case 4 can also have the same polarity as the negative electrode. In that case, the material of the battery case 4 is preferably nickel-plated iron or stainless steel. Moreover, it is preferable to use a nickel material for the electrode lead connected to the battery case 4.
(4) In the above-described embodiment, the battery 1 is provided with the flat rectangular secondary battery main body 2. However, the shape of the secondary battery main body 2 is not particularly limited, and may be, for example, a cylindrical battery. Of course.
[Brief description of the drawings]
FIG. 1 is a perspective view of a battery showing an embodiment of the present invention. FIG. 2 is an exploded sectional view of a resin lid and a battery body. FIG. 3 is a sectional view of a resin lid and a battery body. Enlarged sectional view of the connecting part between the resin lid and the battery body showing the embodiment [Explanation of symbols]
3 ... Resin lid (second lid)
5 ... Power generation element 6 ... Battery cover (first cover)
8 ... Negative electrode internal terminal (extraction electrode)
16 ... Connection protrusions 21, 22 ... Metal plate (insert parts)
25, 27 ... external connection terminals

Claims (2)

A metal battery case that houses the power generation element, a metal first lid that closes an opening of the battery case and is electrically connected to one of the positive electrode and the negative electrode of the power generation element; An extraction electrode that is electrically insulated from the first lid and is connected to the other of the positive electrode and the negative electrode, and a resin-made second lid that is overlapped with the first lid The second lid is integrally provided with a metal insert part by insert molding, and the second lid is fixed to the first lid by fixing the insert part to the first lid. And the second lid is provided with a pair of external connection terminals electrically connected to the insert part and the extraction electrode, respectively. A metal battery case having a flat rectangular shape that accommodates the power generation element inside, and covering the opening of the battery case and being electrically connected to one of the positive electrode and the negative electrode of the power generation element and close to both ends A metal first lid provided with a pair of connection protrusions and an extraction electrode electrically insulated from the battery lid and connected to the other electrode of the positive electrode and the negative electrode; The metal first and second insert parts are provided integrally by insert molding, and the second lid is overlapped with the first lid, and the second lid includes the first and second lids. Both insert parts are fixed to the first lid by being fixed to the connection protrusion of the first lid, and a pair of external connection terminals are provided on the second lid, The connection terminal is connected to the first insert part, and the other Battery part connecting terminals, characterized in that connected to the lead electrode via a circuit element.

Images