JP2003022790A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack which can aim at miniaturization and reduction of cost. SOLUTION: It is the battery pack 1 which is constituted of a secondary battery body 2 which contains a power generation element 4 in a battery case 7, and a terminal cover 41 which covers the one end side of this secondary battery body 2. A pair of positive/negative internal terminals 13 and 23, which are connected to the power generation element 4, are provided the one end side of the battery case 7, and these internal terminals 13 and 23 are covered by the terminal cover 41. In the terminal cover 41, a circuit element 15 connected to the internal terminals 13 and 23 is arranged, and it is made so that the internal terminals 13 and 23 may be connected to an external circuit through the terminal cover 41.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a battery pack.

[0002]

2. Description of the Related Art For example, a battery pack such as a lithium battery is used in an electronic device such as a mobile phone. This battery pack has, for example, the following structure. That is, positive and negative terminals are led out from the upper and lower surfaces of the rechargeable battery body that houses the power generating element in an aluminum case, and a nickel lead is connected to one terminal through an insulating tape. , To the side surface where the other terminal is led out. Further, the secondary battery main body is housed in a plastic case together with the protective circuit board.

[0003]

In recent years, there has been a demand for downsizing and cost reduction in order to further reduce the size and weight of electronic devices such as mobile phones. However, the above-described conventional structure has a double structure in which the secondary battery main body is housed in the plastic case, and therefore there is a limit to downsizing and cost reduction.

The present invention was completed in view of the above circumstances, and an object of the present invention is to provide a battery pack which can be downsized and reduced in cost.

[0005]

As a means for achieving the above object, the invention of claim 1 is a secondary battery main body in which a power generating element is housed in a battery case, and one end side of the secondary battery main body. A terminal cover for covering the battery case, wherein a pair of positive and negative internal terminals connected to the power generating element is provided on the one end side of the battery case, and the internal terminals are covered with the terminal cover, and the terminal cover is provided. A feature is that a circuit element connected to the internal terminal is arranged in the cover, and the internal terminal is connected to an external circuit through the terminal cover.

According to a second aspect of the present invention, in the first aspect, a lock protrusion is provided on one of the secondary battery body and the terminal cover, and the lock protrusion is provided on the other. It is characterized in that the secondary battery main body and the terminal cover are assembled by engaging with the lock receiving portion.

[0007]

<Operation and effect of the invention><Invention of claim 1> In the battery pack according to claim 1, a pair of positive and negative internal terminals connected to the power generating element are provided at one end side of the battery case, and the internal terminals are provided by a terminal cover. Since the structure is covered, it is not necessary to guide the nickel lead to the other end side where the other terminal is led out along the case, and it is not necessary to cover the side surface part with the plastic case. Since the circuit elements necessary for connection with the external circuit are arranged in the terminal cover, all the electrically necessary elements are located in the terminal cover, and the entire secondary battery body is There is no need for a plastic cover to cover.

<Invention of Claim 2> In order to assemble the battery pack according to Claim 2, it is sufficient to engage the lock projection with the lock receiving portion, so that the terminal cover can be easily assembled.

As a battery pack that does not use a plastic case, it is conceivable to fix a protective circuit or the like on the side surface of the secondary battery main body with resin by low pressure molding. However, in this way, the resin melted at the time of molding comes into direct contact with the main body of the secondary battery, so the main body of the secondary battery is heated,
There is concern that the performance of the secondary battery body may deteriorate. On the other hand, in the battery pack according to the second aspect, there is no risk of the secondary battery body being heated during assembly, and therefore deterioration of the secondary battery body can be prevented.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION <First Embodiment> A first embodiment of the present invention will be described in detail with reference to FIGS. The battery pack 1 of the present embodiment is configured by attaching a rectangular terminal cover 41 to one side surface of the flat prismatic secondary battery main body 2. First, the secondary battery main body 2 will be described.

Although not shown in detail, the power generating element 4 of the main body 2 of the secondary battery has a flat spiral shape in which a strip-shaped negative electrode and a positive electrode are wound via a separator. A pair of positive and negative lead members 3 and 5 are led out from the one end side of the power generation element 4 in the wound state at predetermined intervals on the left and right sides.

The power generating element 4 is inserted into the battery case 7 in the shape of a rectangular container from the end side of the lead members 3 and 5 not led out. The battery case 7 is formed, for example, by drawing a plate material made of aluminum, and its opening is closed, for example, by a laser-welded lid 9 also made of aluminum.

A positive connecting piece 11 made of, for example, aluminum is welded to the left side of the drawing on the inner surface of the lid 9, and the positive connecting piece 11 is electrically connected to the positive lead member 3 of the power generating element 4. ing. On the outer surface of the lid 9, a positive electrode internal terminal 13 is welded at a position corresponding to the positive connection piece 11. The positive electrode internal terminal 13 is made of clad steel in which a nickel base material is coated with aluminum, and is welded to the outer surface of the lid 9 so that the contact surface with the lid 9 is aluminum.

On the outer surface of the lid 9, a positive electrode internal terminal 13 is provided.
On the right side of the drawing, a circuit element 15 made of, for example, a PTC element is adhered by a resin 17 having excellent thermal conductivity. Positive electrode internal terminal 1 via nickel piece 19
3 is connected. On the other hand, a negative electrode internal terminal 23 is provided on the right side of the circuit element 15 so as to be insulated from the lid 9. The negative electrode internal terminal 23 has a shaft portion 23 provided on the lower surface of the negative electrode internal terminal 23 after the bush 27 made of plastic is fitted into the through hole 28 formed in the lid 9.
A is penetrated into the bush 27, the insulating plate 31 and the negative connection piece 21 are fitted into the shaft portion 23A from the lower surface side of the lid 9, and the shaft portion 23A is caulked to be fixed.

The lid 9 is provided with a safety valve 37 on the right side of the negative electrode internal terminal 23 in the figure. The safety valve 37 is made of, for example, an aluminum thin film that covers the elliptical through hole provided in the lid 9.

Next, the terminal cover 41 will be described. The terminal cover 41 is formed in the shape of a square cylinder with a bottom, and is attached so that the opening surface is on the secondary battery main body 2 side. The opening surface of the terminal cover 41 has substantially the same shape as the upper side surface of the secondary battery body 2, and is formed so as to cover the upper side surface of the secondary battery body 2.

The terminal cover 41 has a pair of positive and negative electrodes plated with gold using nickel as a base material at a position slightly shifted to the right from the position directly above the circuit element 15 and the negative electrode internal terminal 23 provided on the lid 9. Charging / discharging terminals 45 and 47 are provided by insert molding.

The positive charge / discharge terminal 45 is connected to the protective circuit element 15 via a nickel lead 49 inside the terminal cover 41. On the other hand, the negative charge / discharge terminal 47 is connected to the negative electrode internal terminal 23 via the nickel lead 50 inside the terminal cover 41.

Further, the terminal cover 41 is provided with a welding through hole 52 at a position substantially right above the positive electrode internal terminal 13, the circuit element 15 and the negative electrode internal terminal 23 provided on the lid 9, and this welding is performed. A pin for welding the nickel leads 49 and 50 can be inserted through the through hole 52 for use. It should be noted that the terminal cover 41 is provided with gas vent holes 51 and 53 located almost directly above the safety valve 37 and on the side.

Here, the secondary battery body 2 and the terminal cover 41
The assembly structure with and will be described. On the outer surface of the lid 9 of the secondary battery main body 2, two lock receiving portions 39, 39 made of, for example, aluminum and having a bottomed cylindrical shape are provided near both ends. The lock receiving portions 39, 39 are fixed by welding the bottom surface to the outer surface of the lid 9 so that the openings thereof face the upper side of the lid 9.

On the other hand, the terminal cover 41 is provided with lock protrusions 43, 43 at positions almost directly above the two lock receiving portions 39, 39 provided on the lid 9. The lock protrusions 43, 43 are formed of a cylinder having a cross section that is substantially the same as the cross section of the openings of the lock receiving portions 39, 39, and the lock protrusions 43, 43 are press-fitted into the openings of the lock receiving portions 39, 39. By doing so, it is engaged and the terminal cover 41 is fixed to the secondary battery main body 2.

The positive and negative charging / discharging terminals 45 and 47 are electrically connected as follows. Prior to attaching the terminal cover 41 to the secondary battery main body 2, nickel leads 49 and 50 are welded to the back surfaces of the positive and negative charge / discharge terminals 45 and 47. Therefore, the terminal cover 41 is attached to the secondary battery body 2 with the tips of the nickel leads 49 and 50 connected to the upper surfaces of the circuit element 15 and the negative electrode internal terminal 23, respectively. Then, the tip pin of the ultrasonic welding horn is inserted into the welding through hole 52 of the terminal cover 41 and welded.

In the present embodiment, a pair of positive electrode internal terminal 13 and negative electrode internal terminal 23 connected to the power generating element 4 are provided on one side surface of the battery case 7, and the positive electrode internal terminal 13 and the negative electrode internal terminal 23 are covered by the terminal cover 41. Since the structure is covered, it is not necessary to guide the nickel lead to the side surface where the other terminal is led out along the case, and it is not necessary to cover the side surface portion with the plastic case. The circuit element 15 required for connection with the external circuit is the terminal cover 4
Since it is arranged in the terminal 1, all the electrically necessary elements are located in the terminal cover 41, and the plastic cover for covering the entire secondary battery main body 2 is unnecessary.

In order to assemble the battery pack 1, it is sufficient to engage the lock projections 43, 43 with the lock receiving portions 39, 39, so that the terminal cover 41 can be easily assembled. In addition, in the battery pack 1 of the present embodiment, since there is no possibility that the secondary battery main body 2 is heated during assembly, deterioration of the secondary battery main body 2 can be prevented.

<Second Embodiment> Next, a second embodiment will be described with reference to FIG.
However, the same reference numerals as those of the first embodiment will be given to omit duplicate description, and only different points will be described.

The secondary battery main body 2 is inserted in a battery case 7 similar to the battery pack 1 of the first embodiment.
The positive electrode internal terminal 13 is provided on the outer surface of the lid 9 on the left side of the drawing.
Is provided, and the negative electrode internal terminal 23 is provided on the right side of the drawing. A strip-shaped circuit board 61 having a width substantially the same as that of the lid 9 and a length shorter than that of the lid 9 is connected to the positive electrode internal terminal 13 and the negative electrode internal terminal 23. Circuit board 6
1, the left end and the positive electrode internal terminal 13 are electrically connected via the nickel lead 63 so that they are substantially parallel to the upper surface of the lid 9 while maintaining a predetermined distance, and the right end and the negative electrode internal terminal 23. Similarly, are provided while being electrically connected via the nickel lead 63. Lid 9 of circuit board 61
The circuit element 65 is arranged on the surface facing to, and the terminal portion 67 is provided on the back surface thereof. Then, a resin-made terminal cover 41 having a bottomed rectangular tube shape is attached from above the lid 9 of the secondary battery main body 2 with its opening surface facing downward. The terminal cover 41 is provided with a through hole 69 at a position corresponding to the terminal portion 67 provided on the circuit board 61. , The terminal portion 67 is exposed. Battery pack 1 configured in this way
Also by the above, the same operational effect as that of the first embodiment can be obtained.

<Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the following embodiments are also included in the technical scope of the present invention. In addition to the above, various modifications can be made without departing from the scope of the invention.

(1) In the above embodiment, the circuit element 1
Although 5 is a PTC element, it is not limited to this and may be a thermal fuse, a thermal protector, an identification resistor, an NTC, a thermistor, or the like.

(2) In the above-described embodiment, the secondary battery main body 2 is provided with the lock receiving portion 39, and the terminal cover 41 is provided with the lock protrusion 43. However, the present invention is not limited to this. For example, it goes without saying that the secondary battery main body 2 may be provided with the lock protrusion 43 and the terminal cover 41 may be provided with the lock receiving portion 39.

(3) In the above-mentioned embodiment, the secondary battery main body 2 and the terminal cover 41 are fixed by the lock receiving portion 39 and the lock protrusion 43.
The present invention is not limited to this, and any method may be used as long as the secondary battery main body 2 and the terminal cover 41 are integrated. Needless to say, the structure may be fixed by nails or adhesive.

(4) In the above embodiment, the battery pack 1 is provided with the flat prismatic secondary battery main body 2, but the shape of the secondary battery main body 2 is not particularly limited. For example, a cylindrical battery,
Needless to say, the battery may be of a type in which the battery case is made of a resin film laminated with a metal film.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a battery pack according to a first embodiment.

FIG. 2 is a perspective view of the same battery pack.

FIG. 3 is a sectional view of the same battery pack.

FIG. 4 is a sectional view of the negative electrode internal terminal of the battery pack.

FIG. 5 is a sectional view of a battery pack according to a second embodiment.

[Explanation of symbols]

1 ... Battery pack 2 ... Secondary battery body 4 ... Power generation element 7 ... Battery case 13 ... Positive electrode internal terminal 15 ... Circuit element 23 ... Negative electrode internal terminal 39 ... Lock receiving part 41 ... Terminal cover 43 ... Lock protrusion

Claims (2)

[Claims] 1. A battery pack having a secondary battery body containing a power generating element in a battery case, and a terminal cover for covering one end side of the secondary battery body, wherein the one end side of the battery case is provided. Is provided with a pair of positive and negative internal terminals connected to the power generating element, the internal terminals are covered with the terminal cover, and the circuit element connected to the internal terminals is arranged in the terminal cover, and the terminal cover is provided. A battery pack characterized in that its internal terminals are connected to an external circuit. 2. A lock protrusion is provided on one of the secondary battery body and the terminal cover, and the lock protrusion is engaged with a lock receiving portion provided on the other of the secondary battery main body and the terminal cover. The battery pack according to claim 1, wherein the secondary battery body and the terminal cover are assembled together.