JP4724907B2 - battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery in which a cover plate provided with a safety valve and a terminal is attached to an opening of a battery container.
[0002]
[Prior art]
As shown in FIG. 4, the lithium ion secondary battery includes a cylindrical battery in which a lid 21 is attached to an upper end opening of a cylindrical container 1 containing a battery element 2. This lithium ion secondary battery is provided with a safety valve inside a lid 21 made of a stainless steel plate combined with a button, and this lid 21 is fitted into the upper end opening of the stainless steel battery container 1 via a packing 22 to surround the periphery. The positive terminal is formed by caulking. Moreover, the battery container 1 becomes a negative electrode terminal.
[0003]
[Problems to be solved by the invention]
However, the cylindrical lithium ion secondary battery hermetically seals the inside of the battery container 1 by caulking through the packing 22, so that the processing accuracy is not necessarily high. Due to aging, it becomes difficult to maintain reliable airtightness over a long period of time. For this reason, in particular, in a large-sized lithium ion secondary battery, there has been a request for securely sealing the lid 21 to the upper end opening of the battery container 1 by welding instead of caulking. However, when the lid 21 is welded to the battery case 1, it is electrically connected to the negative electrode terminal. Therefore, it is necessary to insulate and attach the positive electrode terminal to the lid 21 by a reliable method other than packing. Since a safety valve is provided, there is a problem that the positive electrode terminal cannot be arranged in a sufficient size.
[0004]
The present invention has been made to cope with such a situation, and a terminal is attached to a cover plate welded to a battery container via an insulating sealing material such as a glass hermetic seal and connected to the terminal. An object of the present invention is to provide a battery capable of ensuring the sealing of the inside of the battery container by arranging the terminal plate above the safety valve of the lid plate.
[0005]
[Means for Solving the Problems]
In the battery of claim 1, a safety valve is provided on the lid plate welded to the upper end opening of the battery container, and the terminal material is sealed through the terminal hole provided in the lid plate via an insulating sealing material. An insulating plate provided with a terminal port into which the upper end projecting portion of the terminal material is fitted and a vent port that opens above the safety valve is fixed on the cover plate, and at least the vent port is provided on the insulating plate. And a terminal plate connected and fixed to the upper end of the terminal material fitted in the terminal port.
[0006]
According to the invention of claim 1, the lid plate is welded to the upper end opening of the battery container, and the terminal material is insulated by the insulating sealing material and sealed to the lid plate. The airtightness inside the container can be maintained. In addition, since the terminal plate connected to the terminal material is disposed above the safety valve via the insulating plate, a sufficiently large terminal can be provided on the lid plate. Furthermore, when the pressure inside the battery container rises abnormally and the safety valve opens, the high-pressure gas emitted from the safety valve passes through the ventilation hole of the insulating plate, and the gap between the peripheral edge of the terminal plate covering the top Will be released to the outside. In addition, when the terminal plate is connected and fixed only to the upper end portion of the terminal material, the terminal plate can be lifted by the high-pressure gas ejected in large quantities, and can be discharged outside through the lifted gap.
[0007]
In the battery of the present invention, the terminal plate, preferably Rukoto vents leading to vent the insulating plate is formed.
[0008]
If this way to vent holes are formed in the terminal plate, when the safety valve of the cover plate is opened, the high pressure gas to be ejected through the vent of the insulating plate so that it can be released from the vent hole to the outside become. Further, by forming such a ventilation hole, the terminal plate is not only connected and fixed to the upper end portion of the terminal member, the peripheral portion can be fixed in close contact to the insulating plate. However, even if the terminal plate is connected and fixed only to the upper end of the terminal material, if there is not a large amount of high-pressure gas, this terminal will be discharged if it is discharged only through the vent hole and ejected in large quantities. It can be made to discharge also from the crevice which the board raised.
[0009]
In the battery of the present invention, on the insulating plate, it covers the upper terminal plate, and Ru is fixed the upper insulating plate in which an opening is formed above the portion covering the vent of the insulating plate in the terminal plate It is preferable .
[0010]
If placed it thus around the terminal plate is the upper insulating plate covering, and exposed between the periphery of the terminal plate and the insulating plate, it is possible to prevent the or up inadvertently terminal plate curling it can. In this case, when the safety valve of the lid plate is opened, high-pressure gas may be released only through the vent hole of the terminal plate as described above, but the peripheral edge of the opening portion of the upper insulating plate regardless of the presence or absence of the vent hole. It is also possible to release the terminal board that has been locked at the portion and lift it, and to release it from the lifted gap.
[0011]
In the battery of the present invention, the safety valve, closes the opening hole of the cover plate with a thin metal plate having grooves, it is preferable that the sealed to the cover plate by welding the periphery of the metal plate.
[0012]
Thus if the safety valve is only be formed as a separate thin metal plate and cover plate, is possible to perform stable operation by controlling the depth or the like of the plate thickness and the groove of the metal plate with high precision it can.
[0013]
In the battery of the present invention, the insulating plate, it is preferably fixed on the cover plate by a double-sided tape.
[0014]
Thus lever using double-sided tape, it is possible to stick to conveniently cover plate on the insulating plate.
[0015]
In the battery according to the present invention , a metal mounting plate is fixed by welding to at least a portion on the lid plate except above the safety valve and the terminal hole, and the insulating plate is fixed to the engaging portion of the mounting plate. It is preferable to be locked and fixed.
[0016]
In this way, if the insulating plate is locked and fixed to the mounting plate welded to the lid plate, the insulating plate can be securely and firmly fixed on the lid plate.
[0017]
In the battery of the present invention, the terminal plate has a disk shape, and a lead portion protrudes from one end of the disk shape, and a locking portion protrudes from the opposite end of the lead portion, wherein with the lead portion is connected and fixed to the upper end portion of the terminal member, it is preferable that the engagement portion is attached stopped insulating plate.
[0018]
In addition, as a method of fixing the locking portion to the insulating plate, for example, when the upper insulating plate as described above is fixed, a method of pressing the locking portion against the insulating plate with the upper insulating plate is used. Regardless of the presence or absence of the upper insulating plate, a method of attaching the locking portion to the insulating plate with a double-sided tape or the like can also be used.
[0019]
If such a locking portion is fixed to the insulating plate, when the terminal plate is pushed up with a strong force from below, the locking portion is detached from the insulating plate, and the terminal plate is moved forward from the lead portion. By bending and lifting, high-pressure gas can be discharged at once.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0021]
1 to 3 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional front view showing a structure of a cylindrical lithium ion secondary battery, and FIG. 2 is a lid of the lithium ion secondary battery. FIG. 3 is an exploded perspective view showing another structure of the lid of the lithium ion secondary battery. In addition, the same number is attached | subjected to the structural member which has the function similar to the prior art example shown in FIG.
[0022]
In the present embodiment, a cylindrical lithium ion secondary battery similar to the conventional example shown in FIG. 4 will be described. In this lithium ion secondary battery, as shown in FIG. 1, a battery element 2 is housed in a cylindrical container 1 and a lid 3 is fitted into the upper end opening of the battery container 1 and sealed by welding. It is what I wore. The battery container 1 is made of stainless steel and becomes a negative electrode terminal by being connected to the negative electrode of the battery element 2 housed inside.
[0023]
As shown in FIG. 2, the cover plate 3 is a disk made of a stainless steel plate having an opening 3 a formed in the center and a periphery thereof being depressed, and is fitted to the upper end opening of the battery container 1 and welded. In order to make it easy to do, the disc-shaped peripheral edge is bent in an annular shape upward. A terminal hole 3 b is opened at a position slightly deviated from the center of the cover plate 3. And the terminal material 5 penetrates and is sealed by this terminal hole 3b through the glass hermetic seal 4 as an insulating sealing material. The terminal hole 3b is bent in an annular shape with the opening edge facing upward so that the glass hermetic seal 4 is formed with a sufficient thickness. The terminal material 5 is a pin made of stainless steel, and upper and lower ends protrude from the glass hermetic seal 4 in the vertical direction, and the lower ends are connected to the positive electrode of the battery element 2 housed in the battery container 1.
[0024]
A disc-shaped safety valve 6 and a ring-shaped holder 7 that are opened when the pressure inside the battery container 1 is abnormally used from above are placed in a recess around the opening hole 3a of the cover plate 3 from above. 7. By welding from above, the periphery of the safety valve 6 is welded to the cover plate 3 to close the opening hole 3a. The safety valve 6 is a thin metal plate made of a nickel plating layer having a cross-shaped groove 6a formed on the surface. The thickness of the metal plate is formed with high accuracy to about 50 μm, and the depth of the groove 6a is set. By forming with a high accuracy of about 30μ, when the pressure inside the battery container 1 reaches a predetermined value, the groove 6a having a remaining thickness of 20μ is surely broken and opened. However, since such a thin safety valve 6 cannot be directly welded to the cover plate 3, a holder 7 of a ring-shaped stainless steel plate is stacked around the safety valve 6 and welding is performed from above.
[0025]
On the disc of the lid plate 3, an insulating plate 8 is adhered and fixed by a double-sided tape 9. The insulating plate 8 is a disc made of an insulating resin such as PBT (polybutylene terephthalate) or PPS (polyphenylene sulfide) whose diameter is slightly smaller than that of the cover plate 3, and is a portion located above the central safety valve 6. The vent 8a is opened at the same time, and the terminal 8b is opened at the portion where the upper end of the terminal material 5 protrudes. Further, the double-sided tape 9 is cut into a C shape so as to adhere between the insulating plate 8 and the cover plate 3 while avoiding the vent holes 8a and the terminal holes 8b.
[0026]
On the insulating plate 8, a terminal plate 10 is disposed so as to block the upper side of the vent hole 8a and the terminal hole 8b. The terminal board 10 is a disk made of a nickel-plated steel plate, but has a shape in which a portion excluding the peripheral edge protrudes upwardly as if a shallow container is faced down. Further, arc-shaped vent holes 10a and 10a are opened at symmetrical positions on both sides of the terminal plate 10 where the circular plate protrudes upward. Further, the terminal plate 10 has a lead portion 10b projecting laterally from one end of a disk shape, and a locking portion 10c projecting laterally from the opposite end of the lead portion 10b. The end portion of the lead portion 10b is connected and fixed to the upper end portion of the terminal member 5 protruding from the terminal port 8b of the insulating plate 8 by welding.
[0027]
On the insulating plate 8, an upper insulating plate 11 is adhered and fixed by a double-sided tape 12. The upper insulating plate 11 is a disk made of the same insulating resin as the insulating plate 8 and having a diameter slightly larger than that of the cover plate 3, and is formed so that the peripheral edge protrudes downward, A terminal hole 11a is opened in such a portion that a protruding portion of the terminal plate 10 is inserted into the portion. Further, the double-sided tape 12 is cut in a C shape so as to fix the upper insulating plate 11 and the insulating plate 8 while avoiding the terminal plate 10 on the insulating plate 8.
[0028]
In the lithium ion secondary battery having the above configuration, the periphery of the cover plate 3 is fitted into the upper end opening of the battery container 1 and sealed by welding, and the terminal material 5 is connected to the cover plate 3 via the glass hermetic seal 4. Unlike the conventional case where sealing is performed by caulking with high processing accuracy through the packing 22 that deteriorates over time as in the past, the airtightness inside the battery container 1 is reliably maintained over a long period of time. Will be able to. Moreover, since the positive electrode of the battery element 2 accommodated in the battery container 1 is connected to the terminal plate 10 via the terminal material 5, the terminal plate 10 having a large area can be used as the positive electrode terminal. Moreover, since the terminal plate 10 is exposed through the terminal hole 11a of the upper insulating plate 11, there is no possibility that the peripheral portion is inadvertently applied with force and is not damaged. Furthermore, even when a strong force or impact is applied to the terminal plate 10 when wiring is performed on the positive electrode terminal, these forces are not directly applied to the terminal material 5, so that the glass hermetic seal 4 is damaged. It does not occur that the airtightness is lowered. Further, when the pressure inside the battery container 1 rises abnormally and the groove 6a of the safety valve 6 is broken and opened, the high-pressure gas in the battery container 1 passes through the vent 8a of the insulating plate 8 and passes through the terminal board. 10 through the vent holes 10a, 10a. In addition, when a large amount of high-pressure gas is ejected, it is not sufficient to escape from the vent holes 10a, 10a, and the terminal plate 10 is pushed up with a strong force from below. When the terminal plate 10 is bent and lifted from the lead portion 10b, the high-pressure gas can be discharged at once.
[0029]
In the above embodiment, the case where the insulating plate 8 is fixed to the lid plate 3 with the double-sided tape 9 has been described, but it may be fixed via the mounting plate 13 as shown in FIG. The mounting plate 13 is formed by forming a U-shaped notch for avoiding the vent hole 8a and the terminal port 8b on the insulating plate 8 on a disc made of a stainless steel plate, on both sides of the U-shaped notch. The formed locking pieces 13a, 13a are bent upward. The insulating plate 8 is provided with slit-like locking holes 8c and 8c at positions corresponding to the locking pieces 13a and 13a, respectively. Then, the mounting plate 13 is fixed on the lid plate 3 by welding, and the locking pieces 13a and 13a of the mounting plate 13 are inserted into the locking holes 8c and 8c of the insulating plate 8 from below so that the protruding portion is on the outside. The insulating plate 8 is also locked and fixed by bending. When such a mounting plate 13 is used, the labor of processing and assembly increases, but the insulating plate 8 can be firmly and firmly fixed.
[0030]
Moreover, although the case where the vent holes 10a and 10a were opened in the terminal board 10 was demonstrated in the said embodiment, if there is sufficient clearance gap between the vent hole 8a and the terminal board 10 which covers this, the vent hole 10a. , 10a do not necessarily need to be opened. Furthermore, although the said embodiment demonstrated the case where a large amount of high-pressure gas from the inside of the battery container 1 was discharged when the terminal board 10 lifted, if the magnitude | size of the vent holes 10a and 10a is enough, this terminal board 10 may be fixed to the insulating plate 8 or the upper insulating plate 11. Moreover, since the upper insulating plate 11 protects the terminal plate 10, it does not necessarily have to be attached. In this case, it is preferable that the terminal plate 10 is fixed or locked to the insulating plate 8 except for the lead portion 10b.
[0031]
In the above embodiment, the case where the safety valve 6 is formed of a thin metal plate different from the lid plate 3 has been described. However, a groove can be directly formed in the lid plate 3 to form a safety valve. However, if the safety valve 6 is made of another metal plate, the remaining thickness of the groove 6a can be controlled with high precision so that stable operation can be performed by forming it with a plating layer as in this embodiment. Can do. Furthermore, this safety valve is not limited to a type that opens when the groove is broken, and any type of safety valve may be used as long as it is opened by receiving an abnormally high pressure inside the battery container 1. . For example, a safety valve of a type in which the valve body opens the opening against the bias of the spring material when the pressure inside the battery container 1 exceeds a predetermined value can be used. Moreover, although the said embodiment demonstrated the case where only a safety valve was provided in a lithium ion secondary battery, safety mechanisms, such as a polyswitch which restrict | limits an electric current according to a temperature rise, can also be provided. For example, if a negative electrode plate is fixed to the bottom surface of the battery case 1 via a polyswitch sheet, the current passing through the negative electrode plate can be limited in accordance with the temperature rise of the battery case 1.
[0032]
Moreover, although the said embodiment demonstrated the case where the terminal plate 10 comprised a positive electrode terminal and the battery container 1 comprised the negative electrode terminal, these positive / negative electrodes can also be reversed. Furthermore, not only the case where the battery case 1 itself is used as a terminal, but also a terminal having a pole different from that of the terminal plate 10 can be provided.
[0033]
In the above embodiment, a cylindrical lithium ion secondary battery has been described. However, the type of battery is not limited to a lithium ion secondary battery, and a lid plate may be welded to the upper end opening of the battery container. For example, it can be similarly applied to a battery having an arbitrary shape such as a square.
[0034]
【The invention's effect】
As is apparent from the above description, according to the battery of the present invention, the cover plate is welded to the upper end opening of the battery container, and the terminal material is insulated by an insulating sealing material such as a glass hermetic seal. As a result, it is possible to maintain reliable airtightness for a long period of time. In addition, since a terminal plate that covers the upper side of the safety valve is connected to this terminal material, a sufficiently large terminal can be provided on the lid plate. Furthermore, if the pressure inside the battery container rises abnormally and the safety valve opens, the high pressure gas is released through the gaps in the terminal board vents and peripheral edges, or the gap formed by lifting the terminal board. It can be released to the outside.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional front view showing a structure of a cylindrical lithium ion secondary battery according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view showing a structure of a lid of a lithium ion secondary battery according to an embodiment of the present invention.
FIG. 3 is an exploded perspective view showing another embodiment of the lid of the lithium ion secondary battery according to the embodiment of the present invention.
FIG. 4 is a longitudinal sectional front view showing a structure of a cylindrical lithium ion secondary battery, showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Battery container 3 Cover plate 3a Opening hole 3b Terminal hole 4 Glass hermetic seal 5 Terminal material 6 Safety valve 8 Insulating plate 8a Vent 8b Terminal port 8c Locking hole 9 Double-sided tape 10 Terminal plate 10a Vent hole 10b Lead part 10c Locking part 11 Upper insulating plate 11a Terminal hole 12 Double-sided tape 13 Mounting plate 13a Locking piece

Claims (1)

  A safety valve is provided on the lid plate welded to the upper end opening of the battery container, and a terminal material is passed through and sealed in a terminal hole provided in the lid plate via an insulating sealing material. An insulating plate provided with a terminal port into which the upper end protruding portion of the terminal material is fitted and a vent port that opens above the safety valve is fixed, and at least above the vent port is covered on the insulating plate. A battery having a terminal plate connected and fixed to an upper end portion of a terminal material fitted in the battery.

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