JP3220681B2 - Battery with battery protection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary battery, such as a lithium ion secondary battery, which is provided with a battery protection device and has a function of protecting the battery itself from overcharging and overdischarging. The present invention relates to a battery provided with a battery protection device adapted to be applied to a flat battery.

[0002]

2. Description of the Related Art Secondary batteries are used to prevent battery damage due to abnormal use such as short-circuiting of battery peripheral circuits, short-circuiting between positive and negative electrodes, and overcharging and overdischarging of equipment using the secondary batteries. Protection function is provided. These include a PTC element that prevents excessive discharge current due to a short circuit, etc., and a safety valve that releases the internal pressure by shutting off the current-carrying circuit due to an abnormal rise in battery internal pressure due to overcharging. The secondary battery itself has these protection functions. It is well known as a function. In addition, a protection circuit is provided in a lithium ion secondary battery to prevent overcharging and overdischarging, etc., and this protection circuit is generally provided in the form of a pack battery together with the lithium ion secondary battery in a case of the pack battery. It is housed and integrated. A battery pack in which such a battery and a protection circuit are housed in a case and integrated is a battery power source for a portable device such as a mobile phone using a secondary battery such as a lithium ion secondary battery. It is well known that it is widely used as an apparatus.

[0003] In addition to the above-described overcharge and overdischarge prevention, the protection circuit can have functions such as interruption of excessive current, battery temperature monitoring, and the like. Thus, a secondary battery having a protection circuit can be formed without forming a battery pack, and a highly versatile secondary battery can be provided. A secondary battery in which a battery and a protection circuit are integrally formed is disclosed in JP-A-11-26.
One disclosed in Japanese Patent No. 029 or the like is known.

[0004]

However, when a battery protection device is integrated with a secondary battery, it is a problem to configure the secondary battery without impairing the form of the secondary battery and suppressing an increase in external dimensions. In particular, the flat secondary battery is configured to be thin to be applied to small devices such as portable devices. It was difficult to integrate the protection device. JP-A-11-260 described above
Also in the battery disclosed in Japanese Patent Publication No. 29, it is morphologically integrated with the battery, but it is a form of a pack battery in which a battery protection device is compactly mounted on the battery. As a battery with a built-in device, it could not be used alone. Further, in the battery of the related art, since an opening is formed in the circuit board in order to expose the electrode portion, the space of the circuit board is wasted. In addition, in order to apply the present invention to a radio wave transmitting device such as a mobile phone, it is necessary to use a metal substrate or a shielded insulating substrate for a circuit board in order to prevent malfunction of the battery protection device due to radio interference.

An object of the present invention is to provide a structure that can be applied to a flat type secondary battery, thereby suppressing an increase in the external dimensions of the secondary battery, and eliminating the need for a battery pack and making it possible to use the battery alone. It is to provide a battery provided with a battery protection device.

[0006]

The present invention SUMMARY OF THE INVENTION To achieve the above object, a battery can that accommodates the power generation element into the container, the battery can to the sealing plate on for sealing the open end of the battery can insulator A battery protection device for protecting the secondary battery from overcharging, overdischarging, etc., is integrally attached to a secondary battery in which the positive electrode or the negative electrode of the battery is set to the protruding terminal provided as described above. In a battery provided with a battery protection device, a connection plate joined to the protruding terminal, a circuit board on which an IC constituting a battery protection circuit is disposed on the inner surface side ,
A spacer is provided to separate the circuit board from the battery can, the connection plate is connected to a predetermined position on the circuit board, and a plurality of input / output terminals provided on the circuit board are exposed to the outside. A circuit board, a spacer, and a connection plate are included, and at the same time, a cover cap is disposed so as to cover the peripheral side of the battery can, and the cover cap is connected to a predetermined position of the circuit board , and the connection plate or The connection plate and the
The inner side of the circuit board is supported by the spacer,
An input / output terminal is formed on the outer surface side of the road board .

[0007] According to the above configuration, the secondary battery and the circuit board are electrically connected to each other by the connection plate and the cover cap on the positive and negative electrodes of the secondary battery, and are integrated by the cover cap. Since the input / output terminals provided on the circuit board are exposed to the outside, the battery integrated with the battery protection device incorporated therein can be used in the same manner as a single battery. The connection plate or the connection plate and the spacer
Support the lower surface of the circuit board, and
By forming input / output terminals on the opposite side),
The input and output terminals to which contact pressure is applied are supported from the bottom
Thus, a stable connection is made.

In the above configuration, the cover cap can be disposed so as to cover the entire peripheral side of the battery can, so that the integration of the battery protection device and the secondary battery can be firmly maintained.

[0009] At least one cut-out portion is formed on the peripheral side of the cover cap, and the cut-out portion is bent inward to abut on the upper end side of the battery can. By forming, the cover cap is more securely fixed to the secondary battery, and at the same time, an opening communicating with the sealing portion of the secondary battery is formed, and a gas vent hole for releasing an abnormal internal pressure of the secondary battery is formed. You.

[0010] Further, by arranging the plurality of input / output terminals asymmetrically, reverse loading of the battery is prevented.

Further, the outer surface side of the circuit board can be covered with a cover plate provided with a window having open input / output terminals, thereby protecting the circuit board.

Also, an IC disposed on the inner surface side of the circuit board
The outer surface side of the mounting portion is provided with at least a 0.1 mm gap between the cover portion and the cover plate, so that an electrical effect due to external pressure applied to the IC can be prevented.

In addition to the above, the following advantageous configuration can be adopted.
Can be.

[0014] By forming the positioning portions of the secondary battery to the scan spacers, thereby facilitating the provision of the on the secondary battery.

Further, by forming a cutout portion in the spacer at a position corresponding to the cutout portion formed in the cover cap, a gas vent passage leading from the secondary battery to the opening formed by the cutout portion is secured. be able to.

Further, by forming a conductor pattern connected to the ground potential on at least the outer surface side of the position where the battery protection circuit IC is provided on the circuit board, a shielding effect by the conductor pattern is provided, and radiation from the device side is achieved. The electrical effect of the IC due to the electromagnetic waves to be generated can be prevented.

Also, by connecting a conductor pattern formed immediately below the battery protection circuit IC at a close position to a thermistor disposed on the inner surface side of the circuit board, the temperature of the IC that conducts heat to the conductor pattern is reduced. The thermistor on the inner side of the circuit board that detects the heat generated by the secondary battery is also sensitive to the heat of the IC, and can respond to the temperature detection between the secondary battery and the IC. it can.

Further, the connecting plate is formed such that a joint portion with the protruding terminal is formed to a thickness corresponding to a distance between the protruding terminal and the circuit board, and connection leads from both ends to the circuit board are formed. The central portion of the circuit board can be supported by the connection plate.

Further, by covering the side peripheral surface with an electrically insulating sheet, the side peripheral surface where one of the polar terminals of the battery is exposed is insulated and covered, thereby preventing an unexpected short circuit.

Further, by forming a perforation surrounding the opening at a position corresponding to the opening formed in the cover cap of the sheet, the opening for degassing is not sealed, and the gas is released. Sometimes it breaks from the perforation.

Further, by forming at least one, and preferably all, of the connection plate, the input / output terminal plate, and the cover cap from a nickel copper alloy, the connection plate is suitable for joining such as soldering and spot welding. Good adaptation to the type of joining means applied to the site.

[0022]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The embodiment described below is an example embodying the present invention, and does not limit the technical scope of the present invention.

In the embodiment described below, a flat type lithium ion secondary battery is integrally provided with a battery protection device for protecting the secondary battery from overcharging, overdischarging, etc. But while being a secondary battery itself,
This is a battery having the function of a battery protection device like a battery pack.

In FIG. 1, a battery 1 according to this embodiment is shown.
Exposes a positive terminal plate 4, a negative terminal plate 5, and a temperature detecting terminal plate 6 on the upper surface thereof, and covers a side peripheral portion with an insulating label 7, so that the secondary battery and the battery protection device are integrally formed in this housing. It has been incorporated. FIG. 2 is an exploded view of the internal structure of the secondary battery, which is joined to a secondary battery 10 configured as a flat type lithium ion secondary battery and a positive electrode input / output terminal (protruding terminal) 25 of the secondary battery 10. A connecting plate 11, a central spacer 12 disposed on the upper surface of the connecting plate 11 to provide a seating surface at the center of the circuit board 9, and formed in an oval ring shape with the secondary battery 10 and the circuit board 9. And a positive terminal plate (input / output terminal) 4 and a temperature detecting terminal plate (input / output terminal), which constitute a peripheral spacer 13 for providing a seating surface for the circuit board 9 and a battery protection circuit and a temperature detecting circuit.
6 is formed by resin molding with a plus terminal window 18 and a temperature detection terminal window 19 for exposing the plus terminal plate 4 and the temperature detection terminal plate 6 formed on the circuit board 9 to the outside. The cover plate 14 includes the components arranged on the secondary battery 10, and comes into contact with a battery can 26 serving as a negative electrode input / output terminal of the secondary battery 10. Cover cap 15
Is provided. These components are assembled on a secondary battery 10 as shown in a sectional view in FIG.

First, the positive input / output terminal 25 of the secondary battery 10
The connecting plate 11 is joined to the connecting plate 11, and leads 11a, 11a extending from both ends of the connecting plate 11 are connected to the openings 12a, 1a.
The center spacer 12 is disposed on the connection plate 11 through 2a. Next, when the peripheral spacer 13 is disposed on the peripheral portion of the secondary battery 10, since the upper surface heights of the central spacer 11 and the peripheral spacer 13 match, the circuit board 9 is stably disposed thereon. Can be set up. FIG. 4 shows the circuit board 9.
3 shows the configuration of the inner surface side (a) and the outer surface side (b) of the circuit board 9, wherein the leads 11 a of the connection plate 11 are passed through lead through holes 23 formed in the circuit board 9.
And is fixed to the conductor pattern by soldering.

As shown in FIG. 4A, on the inner surface side of the circuit board 9, an IC 16 constituting a battery protection circuit for protecting the secondary battery 10 from overcharge and overdischarge, and a PTC element for preventing an excessive current (Positive Temperrat
ure Coefficient 17), secondary battery 10
And a thermistor 20 for detecting the temperature of the IC 16 and the like. Also, on the outer surface side of the circuit board 9, FIG.
As shown in (b), a plus terminal plate 4 and a temperature detection terminal plate 6 are provided so as to be joined to a conductor pattern formed on a substrate. Between the conductor pattern formed on the outer surface side of the circuit board 9 and the conductor pattern formed on the lower surface side,
They are connected to each other by through holes 21 provided at important points. Further, since a conductor pattern having a ground potential is formed on the outer surface side and the inner surface side at the position where the IC 16 is provided, a state in which the IC 16 is shielded by the conductor pattern is obtained, and the battery 1 is mounted on a mobile phone or the like. Even when the IC 16 is used, occurrence of malfunction of the IC 16 due to electromagnetic waves such as radio wave fogging can be reduced.

A cover plate 14 having a positive terminal window 18 and a temperature detection terminal window 19 is provided on the outer surface of the circuit board 9 at positions corresponding to the positive terminal plate 4 and the temperature detection terminal plate 6. Is established. At this time, a gap g of at least 0.1 mm is provided between the cover plate 14 and the circuit board 9 on the opposite side of the IC 16 disposed on the inner side, that is, on the outer side, as shown in FIG. This is because when external pressure such as vibration or impact is applied to the battery 1,
IC1 by pressurization that does not reach C16
The change in the electrical performance due to the deformation of No. 6 can be prevented by providing the gap g.

The cover plate 14 is covered with a cover cap 15 covering the circuit board 9. The cover cap 15 covers the peripheral side surface of the secondary battery 10 and covers the entire surface. As shown in FIG. 2, four connection pieces 27 formed on the upper side of the cover cap 15 are soldered to four conductor patterns 28 formed on the outer surface side of the circuit board 9, and The cover cap 15 which is electrically connected to the battery can 26 which is the negative input / output terminal of the terminal 10 is connected to the ground potential of the circuit board 9. With this connection structure, the upper end of the cover cap 15 functions as the negative terminal plate 5.

As shown in FIG. 2, cutout pieces 29 formed at two places on both sides of the longitudinal side surface of the cover cap 15 are bent inward to come into contact with the upper periphery of the secondary battery 10. To stabilize the fitting structure of the cover cap 15 to the secondary battery 10 and
The opening after bending 9 functions as a vent hole for releasing an abnormal internal pressure of secondary battery 10. Since this gas vent hole is opened to the side, even if gas is ejected from the secondary battery 10, the gas is ejected from the opening in the direction orthogonal to the ejection direction to reduce the ejection pressure. The opening formed by the cutout piece 29 is hidden by the insulating label 7 when the side peripheral surface of the cover cap 15 is covered with the insulating label 7.
As shown in FIG. 1, a perforation 33 is formed at a position corresponding to the cutout piece 29 of the insulating label 7, and the label is broken from the perforation 33 in the event of gas ejection. In addition, four cutouts 31 are formed in the peripheral spacer 13 so as to cope with the inward bending of the cutout piece 29, and a flow path for venting gas is secured.

The peripheral spacer 13 and the central spacer 12
Means that the spacers 2 are integrated with each other as shown in FIG.
2 can also be configured. As shown in FIG. 2B, a positioning projection 32a fitted to the positive electrode input / output terminal 25 of the secondary battery 10 and a crimped side around the upper surface of the secondary battery 10 are provided on the lower surface at the center of the spacer 22. Since the positioning protrusions 32b are formed, the positioning of the spacer 22 on the secondary battery 10 is easy.

In the battery 1 configured as described above, as shown in FIG. 1, a battery protection device is provided only by slightly extending the height of the secondary battery 10, and when the battery 1 is set in a device in this state, Thus, the battery itself has a battery protection function, and a highly reliable battery can be used. Further, the plus terminal (+), the minus terminal (-), and the temperature detection terminal (T) arranged on the upper surface are arranged asymmetrically in the left-right direction, so that reverse loading to the device can be prevented.

FIG. 6 shows the battery 1 according to the present embodiment described above as an electric circuit configuration, and shows essential parts extracted. The electric structure of the battery 1 will be described below by comparing the electric circuit with the structure shown in FIGS.

The battery can 26, which constitutes the negative input / output terminal of the secondary battery 10, is connected to the cover cap 15 and is exposed as a negative terminal plate 5 to the upper end of the battery 1. on the other hand,
The positive electrode input / output terminal 25 of the secondary battery 10 is connected to the circuit board 9 by the connection plate 11, is connected to the PTC element 17 provided on the circuit board 9, and is configured in the IC 16.
It is connected to the plus terminal plate 4 via ET34. The PT
The C element 17 self-heats due to an excessive current due to a temperature-resistance change of its positive characteristic, and its resistance value increases due to a temperature rise to prevent the excessive current. The FET 34 is turned on and off by a control circuit 35 for detecting the state of overcharge or overdischarge.
Under the FF control, the positive circuit is shut off at the time of overcharge or overdischarge to protect the secondary battery 10 from overcharge or overdischarge.

As shown in FIG. 4, the thermistor 20 disposed on the inner side of the circuit board 9, that is, on the side of the secondary battery 10 is provided.
Is connected to the temperature detecting terminal plate 6 and changes its resistance value in response to a change in the temperature of the secondary battery 10. It is possible to detect an abnormal temperature rise by detecting the temperature of 10. Further, the thermistor 20 is configured as shown in FIG.
As shown in (a), the IC at the position where the IC 16 is disposed
Since the IC 16 is connected to the lower conductor pattern 30, the temperature change of the IC 16 transfers the heat to the lower conductor pattern 30 of the IC to give a temperature change to the thermistor 20 and changes its resistance value. The side can detect an abnormal temperature rise of the IC 16 in accordance with the temperature rise of the secondary battery 10.

The connection plate 11, the cover cap 15, the plus terminal plate 4, and the temperature detection terminal plate 6 in the above-described configuration of the battery 1 are formed by using a nickel copper alloy, so that joining such as soldering and spot welding is performed. It is suitable for.
The connection plate 11 is joined to the positive electrode input / output terminal 25 of the secondary battery 10 by spot welding or ultrasonic welding, and leads 11 a extending from both ends thereof are soldered to the conductor pattern of the circuit board 9. Even when a different joining method is used depending on such a single member, the nickel copper alloy can cope with any of the joining methods, and a good joining state can be obtained. Also, in the cover cap 15, when performing the soldering of the connection piece 27 to the circuit board 9 and the ultrasonic welding or the spot welding of the secondary battery 10 to the battery can 26, any of the joining methods is used. Can also be adapted. The plus terminal plate 4, the temperature detection terminal plate 6, and the minus terminal plate 5 formed on the upper end of the cover cap 15 are connection contacts with which connection probes of devices using the battery 1 make conductive contact. Nickel copper alloy can provide conductive contact with low contact resistance.

The positive input / output terminal 25 of the secondary battery 10
7 (a) and 7 (b), the connecting structure of the connecting plate 11 and the central spacer 12 for connecting the The central spacer 12 for supporting the portion can be omitted, and the connecting plates 36 and 37 can have the supporting function. The connection plates 36 and 37 are respectively
b and 37b are formed to have a thickness corresponding to the distance between the positive input / output terminal 25 and the circuit board 9, and leads 36a and 37a are formed to extend from both ends thereof. This connection plate 36
Alternatively, the connection plate 37 is joined to the positive input / output terminal 25,
By arranging the circuit board 9 thereon, the central portion of the circuit board 9 is supported in a stable state, so that the device side that is in contact with and connected to the plus terminal plate 4 arranged in the central portion of the circuit board 9 Can be satisfactorily coped with the contact pressure of the connection probe.

In the configuration of the present invention described above, the connection plates 11, 36, and 37 are constituted by PTC elements, so that the PTs disposed on the circuit board 9 are provided.
The C element 17 can be eliminated to increase the space on the circuit board 9, which is suitable for applying to a smaller secondary battery 10.

Further, the secondary battery 10 applied to the present embodiment
Shows an example of a lithium ion secondary battery in which a positive electrode input / output terminal 25 is provided in a sealing portion and a battery can 26 is used as a negative electrode input / output terminal. Needless to say, a battery can be similarly implemented by changing the connection.

[0039]

As described above, according to the present invention, since the battery protection device is integrally formed with the secondary battery, the battery can be used as if only the battery is loaded in the device without providing a battery pack. This can contribute to miniaturization and weight reduction of equipment using a secondary battery as a power supply.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a battery according to an embodiment.

FIG. 2 is a perspective view showing an assembled structure by disassembling each component.

FIG. 3 is a cross-sectional view illustrating a structure of a battery protection device configured on a secondary battery.

FIGS. 4A and 4B show the configuration of a circuit board, FIG.
Is a plan view of the upper surface side.

5A is a perspective view showing a modification of the spacer, FIG.
(B) is a sectional view taken along line AA.

FIG. 6 is a circuit diagram showing the electrical configuration of the battery according to the embodiment.

FIGS. 7A and 7B are perspective views showing modified examples of the connection plate; FIGS.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 4 Plus terminal plate 5 Minus terminal plate 6 Temperature detection terminal plate 7 Insulating label 9 Circuit board 10 Secondary battery 11, 36, 37 Connection plate 12 Central spacer 13 Peripheral spacer 14 Cover plate 15 Cover cap 16 IC 18 Plus terminal window Reference Signs List 19 temperature detection terminal window 20 thermistor 22 spacer 25 positive electrode input / output terminal (protruding terminal) 26 battery can 29 cutout piece 30 IC lower conductor pattern 31 notch 32a, 32b positioning projection 33 perforation

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01M 2/02-2/04 H01M 2/34 H01M 10/42-10/48 H02J 7/00-7 / 36

Claims (14)

(57) [Claims] 1. A the battery can that accommodates the power generation element into the container,
Overcharging this secondary battery into a secondary battery in which a positive electrode or a negative electrode of the battery is respectively set to a protruding terminal provided insulated from the battery can on a sealing plate for sealing the open end of the battery can A battery provided with a battery protection device integrally mounted with a battery protection device for protecting against overdischarge, etc., wherein a sealing plate of the battery can, a connection plate joined to the protruding terminal, and an IC constituting a battery protection circuit A circuit board disposed on the inner surface side, a spacer for separating the circuit board from the battery can is disposed, the connection plate is connected to a predetermined position of the circuit board, and the circuit board is mounted on the circuit board. A plurality of input / output terminals provided are exposed to the outside, a circuit board, a spacer, and a connection plate are included, and a cover cap is provided so as to cover the peripheral side of the battery can, and the cover cap is mounted on the circuit board. It is constructed by connecting to a given position And said connecting plate or said contact
The inner side of the circuit board is supported by the connecting plate and the spacer.
A battery provided with a battery protection device , wherein input / output terminals are formed on an outer surface side of the circuit board . 2. A battery provided with the battery protection device according to claim 1, wherein the cover cap is disposed so as to cover the entire peripheral side portion of the battery can. 3. At least one cut-out portion is formed in a peripheral portion of the cover cap, and the cut portion is bent inward to abut on the upper end side of the battery can, and at least one opening is formed in the bent peripheral portion. A battery provided with the battery protection device according to claim 1, wherein the battery protection device is formed. 4. A battery provided with the battery protection device according to claim 1, wherein a plurality of input / output terminals are arranged asymmetrically. 5. A battery provided with the battery protection device according to claim 1, wherein a cover plate provided with a window whose input and output terminals are open is provided on an outer surface side of the circuit board. . 6. The battery protection device according to claim 5, wherein a gap of at least 0.1 mm is provided between an outer surface of the mounting portion of the IC disposed on the inner surface of the circuit board and the cover plate. Equipped battery. 7. A positioning part for a secondary battery on a spacer.
A battery provided with the battery protection device according to any one of claims 1 to 6 . 8. A cover formed on a cover cap on the spacer.
Notch is formed at the position corresponding to the cutout
A battery comprising the battery protection device according to claim 3 . 9. An arrangement of a battery protection circuit IC on a circuit board.
Conductor pattern connected to ground potential on at least the outer side of the device.
A battery provided with the battery protection device according to any one of claims 1 to 8 , wherein the battery protection device is provided with a battery pack. 10. A thermistor disposed on an inner surface side of a circuit board.
The conductor pattern formed immediately below the battery protection circuit IC
10 are connected in close proximity to each other.
Battery having a battery protection device according to one paragraph. 11. A connection plate, wherein a joint portion with a protruding terminal is protruded.
Formed to a thickness corresponding to the distance between the output terminal and the circuit board
Connection leads from both ends to the circuit board are formed
A battery comprising the battery protection device according to claim 1 . 12. The side peripheral surface is covered with an electrically insulating sheet.
A battery comprising the battery protection device according to claim 1 . 13. A seat cover cap formed on a seat.
Perforations surrounding the opening are formed at positions corresponding to the opening
A battery provided with the battery protection device according to claim 12 . 14. A connection plate, an input / output terminal plate, and a cover cap.
At least one of the loops is formed of a nickel copper alloy.
A battery comprising the battery protection device according to claim 1 .