JP2003257386A - Unit battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a unit cell with simple wiring passages and high degrees of freedom of positions or shapes of terminals and a safety valve. <P>SOLUTION: This unit cell 1 has a power storage element containing positive and negative electrodes 5, 6; and a container 2 housing the power storage element, and the container 2 is equipped with a cylindrical body 21; a cover 22 connected to one end of the cylindrical body 21 and in which the positive and negative electrodes 3, 4 are installed; and a bottom plate 23 connected to the other end of the cylindrical body 21 and in which the safety valve 25 is installed, and the thickness of the bottom plate 23 is made thicker than that of the cylindrical body 21. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a single cell,
In particular, the present invention relates to a single battery that can be suitably used as a power source for portable electronic devices such as mobile phones, mobile personal computers, and portable cassette decks.

[0002]

2. Description of the Related Art Generally, a portable unit cell, as shown in a sectional view in FIG. 3, has a power storage element, a container body d having one opening for accommodating the power storage element, and a lid for sealing the opening of the container body. e. The electricity storage element basically includes positive and negative electrode plates a and b, a separator c interposed between the electrode plates, and an electrolytic solution (not shown).

A conventional container is formed by deep-drawing a single metal material made of aluminum, for example. The lid e is made of a plate separate from the container body d, and one electrode terminal, for example, the negative electrode terminal f, is fixed to the center of the lid via an insulating material g, and a safety valve h is provided at a position deviated from the center. Has been formed. The safety valve is formed such that only that part is thinner than other parts of the lid, or the through hole is liquid-tightly closed with a metal foil. The gas is released to prevent the entire battery from exploding. The unit cell having such a structure accommodates the electricity storage element except for the electrolytic solution, joins the negative electrode plate b to the negative electrode terminal f and the positive electrode plate a to the lid e, welds the lid e to the opening, and then covers the lid. The electrolytic solution was injected from a liquid injection port (not shown) provided in e, and the hole was sealed to complete the process.

After completion, the positive and negative electrode terminals on the outer surface of the container are connected to terminals on the external circuit side such as a battery protection circuit, put in an outer case and integrated as a battery pack. At this time, the entire container body d and the lid e have the same electric potential as the positive electrode, but in order to prevent the electrolyte solution from leaking out and causing an external short circuit between the electrode terminals when the safety valve h is activated, the upper surface of the lid e is limited. The connection between the positive electrode and the external circuit is made at the bottom of the container main body d in order to prevent the functions from being concentrated and complicated in a large area. Since the container body d is thin, a plate-shaped positive electrode terminal i is preliminarily bonded to the outer surface of the bottom of the container body in order to avoid affecting the inside of the battery when connecting to an external circuit by spot welding or the like. Has been done.

[0005]

However, since the positive electrode terminal i and the negative electrode terminal f are provided on the surfaces different from each other in the above-described configuration of the unit cell, the wiring of the battery pack in which the battery and the protection circuit are integrated is formed. The route is complicated. Further, since both the negative electrode terminal f and the safety valve h are provided on the lid e,
The position or shape of either one is constrained by that of the other. Therefore, an object of the present invention is to provide a single battery in which the wiring route of the battery pack is simple and the degree of freedom in the positions and shapes of the terminals and the safety valve is high.

[0006]

In order to solve the problem, a unit cell of the present invention is a unit cell provided with a power storage element including positive and negative electrodes and a container for storing the power storage element. Shaped body and joined to one end of the body,
It is characterized by comprising a lid provided with positive and negative electrode terminals and a bottom plate joined to the other end of the main body and having a safety valve formed thereon, wherein the bottom plate is thicker than the main body.

According to the unit cell structure of the present invention, since both the positive and negative electrode terminals are provided on the lid, the wiring route connecting these terminals and the external circuit is simple. Further, since the safety valve is formed on the bottom plate on the opposite side, the position and shape of the terminal are not restricted by the safety valve, while the position and shape of the safety valve are not restricted by the terminal. Therefore, the positions and shapes of the positive and negative terminals can be freely designed within the area range of the lid, and the opening area of the safety valve can be sufficiently secured.

The bottom plate is made of a relatively thick material so as to have a safety valve. This makes it possible to improve the pressure resistance of the battery container and maintain the container structure without separately providing a support or the like for supporting the electricity storage element inside the battery. This configuration is particularly suitable for a small-sized battery in which it is difficult to provide a support and a capacity of 2 Ah or less. Further, unlike the conventional case, the main body has a tubular shape with both ends open, so that such a thin wall molding is possible. The thickness of the lid is not limited, but it is preferable that the lid is thicker than the main body like the bottom plate because the terminal is provided.

In the structure of the present invention, since the safety valve is not formed on the lid, the positive electrode terminal and the negative electrode terminal can be provided at desired positions on the lid. Therefore, it is preferable that the positive electrode terminal and the negative electrode terminal are provided at positions deviated from the center in the surface direction of the lid in directions opposite to each other. This is because the distance between the terminals is increased and the possibility of an external short circuit is reduced.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 A portable unit cell according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a portable lithium-ion secondary battery (hereinafter,
FIG. The battery 1 has a rectangular parallelepiped-shaped container 2 having a container body 21, a lid 22 and a bottom plate 23 in appearance, a negative electrode terminal 3 provided in the center of the lid 22, and a lid 22.
And the positive electrode terminal 4 provided at the eccentric position. Container 2
A power storage element is housed inside. The electricity storage element is interposed between a plurality of rectangular negative electrode plates 5 and positive electrode plates 6 each having an active material formed on the surface of a metal foil or a metal film / organic polymer film laminate film, and the electrode plates 5, 6. Porous separator 7 and an organic electrolyte solution (not shown) filled in the pores of separator 7 and in the gap between the inner surface of container 2 and the electricity storage element
Consists of.

The container body 21 is relatively thin and has a cylindrical shape with both upper and lower ends open. The lid 22 and the bottom plate 23 have the same thickness and are formed thicker than the main body 21. An oval through hole 24 is formed in the center of the bottom plate 23, and a metal foil (thickness is not shown) 25 so as to seal the through hole 24.
Are welded, and the metal foil 25 functions as a safety valve.

Each of the positive and negative terminals 3 and 4 comprises a pole-shaped pole column 31 and 41 and a flat plate-shaped terminal block 32 and 42 provided at the upper end thereof. Then, through holes are formed in the lid 22 at respective positions of the negative electrode terminal 3 and the positive electrode terminal 4, and the respective pole columns 31, 41 are inserted toward the inside of the container 2. The pole 31 of the negative electrode terminal 3 is inserted into the container 2 while being insulated from the container 2 by the ring-shaped insulating member 8, and its lower end is connected to the current collector of the negative electrode plate 5 by rivets. Unlike the negative electrode terminal 3, the pole post 41 of the positive electrode terminal 4 is inserted into the container 2 while maintaining liquid-tight contact with the container 2,
The lower end thereof is connected to the current collector of the positive electrode plate 6 with rivets. Since the battery 1 is provided with the positive and negative terminals 3 and 4 on one end surface of the container 2 and the safety valve 25 on the other end surface as described above, an external short circuit is caused due to leakage of the electrolytic solution when the safety valve 25 operates. Less likely to Moreover, since both the positive and negative terminals 3 and 4 are provided on the same surface, the wiring for connecting to an external circuit such as a protection circuit can be simple.

-Embodiment 2- Another embodiment of a portable unit cell according to the present invention is shown in a sectional view in FIG. In the battery 1 of this embodiment, the negative electrode terminal 3 is also provided at an eccentric position of the lid 22, and the negative electrode terminal 3 and the positive electrode terminal 4 are symmetrically positioned about the vertical center line of the battery 1. Along with that, the current collecting portion of the negative electrode plate 5 is also
Is formed in the corner. In other respects, the battery 1 has basically the same shape and quality as the battery 1 of the first embodiment. According to this invention,
Since the safety valve 25 is provided on the bottom plate 23, the area of the lid 22 can be effectively used so that the distance between the positive electrode terminal 4 and the negative electrode terminal 3 is sufficiently widened. Therefore, in addition to the same function and effect as in the first embodiment, there is an effect that an external short circuit can be prevented more easily than in the first embodiment.

[0014]

As described above, in the unit cell of the present invention, since the positive and negative electrode terminals are both provided on the lid, the wiring route connecting these terminals and the external circuit becomes simple. Moreover, since the electrode terminal and the safety valve are provided on different surfaces of the container, the degree of freedom in the position and shape of the electrode terminal and the safety valve is high, and the design is easy.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a portable single battery according to a first embodiment.

FIG. 2 is a cross-sectional view showing the portable unit cell according to the first embodiment.

FIG. 3 is a cross-sectional view showing a conventional portable unit cell.

[Explanation of symbols]

1 Portable single battery 2 containers 21 container body 22 Lid 23 Bottom plate 25 safety valve 3 Negative electrode terminal 4 Positive terminal 5 Negative electrode plate 6 Positive plate 7 separator

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5H011 AA01 AA04 BB03 CC06 EE04                       KK01                 5H012 AA07 BB00                 5H022 AA09 CC02                 5H029 AJ00 BJ02 BJ23 DJ01 DJ02                       DJ05 HJ04 HJ12

Claims (2)

[Claims] 1. A unit cell comprising an electricity storage element including positive and negative electrodes and a container for accommodating the electricity storage element, wherein the container is joined to a cylindrical body and one end of the body, and positive and negative electrode terminals are provided. A unit cell comprising a lid provided and a bottom plate joined to the other end of the main body and having a safety valve formed thereon, wherein the bottom plate is thicker than the main body. 2. The unit cell according to claim 1, wherein the positive electrode terminal and the negative electrode terminal are located at positions deviated in directions opposite to each other from a center of a surface direction of the lid.