JP2003142046A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery capable of reducing the thermal influence on an insulating sealing part in welding a battery case and a lid, and securing the sealability. SOLUTION: In this battery wherein a terminal material is penetrated and sealed to a terminal port formed on a lid plate welded on an upper end opening part of the battery case through an insulating sealing material made out of an inorganic material, the lid plate is provided with an annular thin wall part around the circumference of the terminal port on a part not kept into contact with the insulating sealing material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery in which a terminal material is penetrated and sealed at a terminal opening of a battery cover plate via an insulating sealing material made of an inorganic material.

[0002]

2. Description of the Related Art Non-aqueous secondary batteries such as lithium ion secondary batteries include a cylindrical type in which a lid is attached to an upper end opening of a cylindrical battery container containing a battery element. This non-aqueous secondary battery is produced by fitting a button-shaped lid made of a combination of stainless steel plates into the upper end opening of a battery container made of stainless steel via packing and caulking the periphery. Then, the lid serves as a positive electrode terminal and the battery container serves as a negative electrode terminal. A safety valve is provided inside the lid.

[0003]

However, in the above cylindrical non-aqueous secondary battery, the inside of the battery container is hermetically sealed by caulking through the packing, but the caulking is not always highly accurate. , The airtightness is reduced,
Since the packing changes over time, it becomes difficult to maintain reliable airtightness for a long period of time.

For this reason, particularly for large-sized non-aqueous secondary batteries, as a method of attaching the lid to the battery container, a welding method has been studied instead of the above caulking process. By using the welding method, the lid can be reliably sealed to the upper end opening of the battery container.

When this welding method is used, since the metal battery container and the lid are connected, the battery container and the lid cannot be used as separate electrode terminals as in the case of caulking using packing. . Therefore, the terminal material is penetrated and sealed to the terminal opening provided on the lid plate through an insulating sealing material made of an inorganic material such as a glass hermetic seal, and this terminal material is used for one of the electrode terminals and the battery container. And the lid are used as the other electrode terminal.

However, when a battery is manufactured by the welding method, the lid expands due to the heat of welding the battery container and the lid. The expansion rate is different between the lid or terminal made of metal and the insulating encapsulant made of an inorganic material.Therefore, depending on the welding conditions, the insulating encapsulation may be misaligned, which may cause cracking or destruction, resulting in airtightness. There was a problem of causing fatal damage to the sex.

The present invention has been made in order to cope with such a situation, and reduces the heat effect on the insulating sealing portion when welding the battery container and the lid, and ensures the airtightness of the insulating sealing portion. The purpose is to provide a new battery.

[0008]

According to a first aspect of the present invention, a terminal material is attached to a terminal port provided on a lid plate welded at an upper end opening of a battery container via an insulating sealing material made of an inorganic material. In the battery that is penetrated and sealed, the cover plate is provided with an annular thin portion in a portion that goes around the terminal opening and is not in contact with the insulating sealing material.

According to the first aspect of the present invention, even if welding is performed at the time of sealing the battery or attaching the parts in the manufacturing process of the battery, heat is not applied to the terminal sealing member, the insulating sealing material, and the insulating sealing portion composed of the terminals. There is little conduction, the temperature rise of the insulating sealing part is small,
Airtightness is ensured without impairing the function of the insulating sealing part,
It is possible to obtain a battery with excellent reliability.

The invention according to claim 2 is the battery according to claim 1, characterized in that a plurality of annular thin portions are provided around the terminal port.

According to the second aspect of the present invention, the plurality of thin portions provided around the terminal opening limit heat conduction,
It is possible to suppress a temperature rise in the insulating sealing portion, eliminate damage due to thermal expansion of the insulating sealing portion, and maintain high airtightness. Further, this thin portion has an excellent feature that it can be easily processed by a mold, is inexpensive in cost, and does not require an extra space, so that no special consideration is required in terms of storage.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing the structure of the non-aqueous secondary battery of the present invention. In FIG. 1, 1 is a battery container, 2 is a battery element, 3 is a cover plate assembly, 4 is an opening of the battery container, 5 is an insulating plate, 6 is a negative electrode lead, 7 is a positive electrode lead, and 8 is a first insulation. Plate, 9 is the second insulating plate, 1
Reference numeral 0 is a third insulating plate, and 11 is a positive electrode terminal.

As an example of the material used, the battery container 1 is made of stainless steel, and the insulating plate 5 is made of polypropylene.
Further, the crimping process 2 is a wound cylindrical type, in which a sheet-shaped positive electrode plate and a sheet-shaped negative electrode plate are wound via a separator.

The steps for producing the non-aqueous secondary battery of the present invention are as follows. First, the battery element 2 is inserted into the battery container 1 having the insulating plate 5 at the bottom, the first insulating plate 8 is placed on the battery element 2, and the negative electrode lead 6 protruding from the battery element 2 is attached to the battery container 1. Connect to the inner sidewall. Next, the second insulating plate 9 is placed on the negative electrode lead 6, the positive electrode lead 7 is bonded to the positive electrode terminal 11 of the cover plate assembly 3, and the third insulating plate 10 is connected to the battery element 2 and the positive electrode terminal 7. Insert in between. Next, the lid plate assembly 3 is inserted into and fitted into the opening 4 of the battery container 1, and the joint between the lid plate assembly 3 and the opening 4 is welded by a laser welding machine. The negative electrode lead 6 of the battery element 2 is connected to the battery container 1, the battery container 1 also serves as a negative electrode terminal, and the positive electrode lead 7 of the battery element 2 is
It is connected to the positive electrode terminal 11 through the first insulating plate 8, the second insulating plate 9, and the third insulating plate 10. Finally, the nonaqueous secondary battery of the present invention is completed by injecting an electrolytic solution through an injection hole (not shown) provided at the bottom of the battery container and then sealing.

FIG. 2 is an exploded perspective view of the main part of the lid plate assembly 3 shown in FIG. In FIG. 2, 12 is a cover plate, 1
3 is a terminal material, 14 is a glass hermetic seal, 15 is an opening, 16 is a safety valve, 17 is a holder, 18 is a fixing ring, and 19 is a projection part.

As shown in FIG. 2, a terminal opening is formed at a position slightly displaced from the central portion of the cover plate 12, and the terminal opening is provided with a glass hermetic seal 14 as an insulating sealing material. The material 13 penetrates and is sealed.

An opening 15 is formed in the center of the cover plate 12, and a safety valve 16 and a ring-shaped holder 17 which are opened from above when the pressure in the battery rises abnormally are placed on the opening 15. By welding from above the holder 17, the periphery of the safety valve 16 is welded to the cover plate 12 and the opening 15 is closed. Further, the fixing ring 18 is attached so as to be inscribed in the lid plate 12,
The projection portion 19 provided on the flat portion of
It is fixed to No. 2 by resistance welding. In addition, the holder 17
The lid plate assembly is completed by providing some insulating plates and insulating tape (not shown) on the top of the.

The safety valve 16 is a thin metal plate made of a nickel-plated layer in which cross-shaped grooves are formed. By precisely forming the thickness of the grooves, the cleavage pressure when the internal pressure rises is controlled. However, since a thin safety valve cannot be directly welded to the lid plate 12, a ring-shaped stainless steel plate holder 17 is placed around the safety valve 16 and welded from above. The lid plate 12 is made of a stainless steel plate having a thickness of 0.6 mm by molding.

FIGS. 3, 4 and 5 are cross-sectional views of essential parts of an example of the non-aqueous secondary battery of the present invention in the vicinity of the terminal port of the cover plate. Further, FIG. 6 shows a cross-sectional view of a main part of a conventional non-aqueous secondary battery in the vicinity of a terminal opening of a lid.

3 to 6, 21 is a battery container, 2
2 is a lid plate, 23 is a terminal port of the lid plate, 24 is a glass hermetic seal portion, 25 is a terminal material, 26 is a thin portion of the lid plate, 2
7 is a welded portion, 28 is a V-shaped groove, 29 is a plurality of U-shaped grooves, 30 is a safety valve, and 31 is a holder.

FIG. 3 is a cross-sectional view of the main part of an example of the vicinity of the terminal opening of the lid of the non-aqueous secondary battery of the present invention. A terminal port 23 is opened at a position slightly displaced from the central portion of the cover plate 22. A terminal material 25 penetrates and is sealed to the terminal port 23 via a glass hermetic seal portion 24 as an insulating sealing material. The terminal opening 23 is bent in an annular shape with its opening edge facing upward so that the glass hermetic seal 24 is formed with a sufficient thickness. The terminal material 25 is a pin made of stainless steel, and the upper and lower ends thereof project vertically from the glass hermetic seal 24, and the lower end is connected to the positive electrode lead of a battery element (not shown) housed in the battery container 21. .

The thin portion 26 of the cover plate, which is not in contact with the glass hermetic seal 24, around the terminal opening has a thickness of 0.3 m.
The thickness of the other portion of the cover plate 22 is 0.6.
It is ½ of mm, and the thin portion 26 of the lid plate is formed so as to surround the terminal port 23. As a result, the safety valve and the holder are welded to the cover plate 22, and the cover plate 22
At the time of welding between the battery case 21 and the battery container 21, the thin portion 26 of the lid plate exerts an effect of suppressing the transfer of heat generated by welding to the terminal port 23, and the glass hermetic portion 2 is heated by high temperature or thermal shock.
It is possible to solve the problem of damaging 4 and reducing the airtightness.

FIG. 4 is a cross-sectional view of essential parts of another example of the non-aqueous secondary battery of the present invention near the terminal opening of the lid. In this example,
A V-shaped groove 28 is provided in a portion around the terminal port 23 that is not in contact with the glass hermetic seal 24 of the lid plate 22, and this groove suppresses heat transfer from the surroundings to the terminal port 23. As a result, damage to the glass hermetically sealed portion 24 is eliminated, and a decrease in airtightness is prevented.

FIG. 5 is a cross-sectional view of a main part of still another example of the vicinity of the terminal port of the lid of the non-aqueous secondary battery of the present invention. In this example, a plurality of U-shaped grooves 29 are provided around the terminal opening 23 in a portion not in contact with the glass hermetic seal 24.
There is a book, and this groove allows the terminal port 2 for heat from the surroundings.
3 to suppress the transmission to the glass hermetic seal part 2
The damage of No. 4 is eliminated and the deterioration of airtightness is prevented.

FIG. 6 is a cross-sectional view of the main part of the conventional non-aqueous secondary battery in the vicinity of the terminal opening of the lid. In the conventional non-aqueous secondary battery, the thickness of the lid plate 22 around the terminal port 23 is the same as that of the other portions of the lid plate 22, and the heat transfer from the surroundings to the glass hermetic seal portion 24 is prevented. There is no suppressing effect.

The shape of the groove provided around the terminal port 23 in the portion of the cover plate 22 that is not in contact with the glass hermetic seal 24 is not limited to the V-shaped shape or the U-shaped shape, and various shapes may be used. can do. Further, the number of grooves provided is not particularly limited, and can be arbitrarily selected according to the size of the battery and the like. Further, the plurality of grooves and the thin portion may be provided concentrically.

The lid plate and terminals are preferably made of stainless steel from the viewpoint of corrosion resistance, and the sealing material also serving as an insulating material is made of an inorganic material such as glass or ceramic. And it is preferable in terms of reliability.

Further, in addition to the above-mentioned cylindrical non-aqueous secondary battery, the present invention is a non-aqueous secondary battery as long as it is a battery of a system in which a safety valve is sealed and a battery container and a lid plate are sealed by welding. Needless to say, the present invention can be applied not only to batteries and cylindrical batteries, but also to prismatic and flat lithium ion batteries, thionyl chloride batteries, thermal batteries, and the like.

[0029]

EXAMPLE FIG. 6 shows a non-aqueous secondary battery according to the present invention (this is referred to as battery A) whose cross section of the main part near the terminal port of the lid plate has the same structure as shown in FIG. A conventional non-aqueous secondary battery (this is referred to as battery B) having the same structure as
The cells were manufactured for each 0 cells, and the hermeticity of the glass hermetically sealed portion was compared. For each battery, the laser welding machine was used to weld the lid plate 12, the safety valve 16 and the holder 17 shown in FIG. 2 and the battery container 21 and the lid plate 22 shown in FIGS. 3 and 6. It was

A pulse YAG laser welder was used for welding. Welding speed of safety valve, holder and lid plate is 30
The constant was 0 mm / min, the number of pulses was 5 / mm, and the welding energy was 1.4 J / pulse. The lid plate and the battery container were welded at a welding speed of 600 mm / min and a pulse number of 5 pieces / mm, and the welding energy was changed in the range of 1.2 to 2.4 J / pulse.

The melted state of the welded portion and the airtightness of the glass hermetic portion in each battery were examined. The melted state of the welded portion was measured by etching the cut surface, and the airtightness of the glass hermetic portion was measured by a helium leak inspection machine.

Table 1 shows welding conditions and results. The unit of welding energy in Table 1 is J / pulse,
"Penetration depth" indicates the penetration depth (unit: mm) of the welded portion between the battery container and the cover plate, "Airtightness" indicates the airtightness of the glass hermetically sealed portion, and "Airtightness" column contains 1
The number of airtight defective products in 0 cell is shown. Deepen.

[0033]

[Table 1]

When joining the battery container and the cover plate, it is preferable that the penetration depth of the welded portion is 0.2 mm or more from the viewpoint of airtightness and strength. In both the battery A of the present invention and the conventional battery B, the penetration deepens as the welding energy increases, but the penetration depth is practically 0.
It is sufficient if it is 2 mm or more, and this condition can be reached with an energy of 1.8 J / pulse or more.

Therefore, the relationship between the welding energy and the hermeticity and penetration depth of the glass hermetic seal at the terminal opening was examined. From Table 1, in the battery A of the present invention,
When the welding energy was 2.2 J / pulse or less, there were no airtight defective products, and when the welding energy was 1.8 J / pulse or more, the penetration depth was 0.2 mm or more.
That is, it was confirmed that good results were obtained for both welding depth and airtightness when the welding energy was in the range of 1.8 to 2.2 J / pulse.

On the other hand, in the conventional battery B, when the welding energy is 1.6 J / pulse, the hermetic seal of the glass hermetically fails, and with a larger welding energy, the number of the hermetically sealed parts increases, which makes practical use difficult. It was confirmed that there is.

Although detailed description is omitted, a method of forming a V-shaped groove around the terminal port as shown in FIG. 4 or a method of forming a concentric U-shaped groove shown in FIG. Similar results can be obtained in other examples of the present invention in which the thickness of the cover plate is one around the terminal opening and is thinner in the portion not in contact with the insulating sealing material than in other portions. Was obtained.

[0038]

As described above, in the non-aqueous secondary battery of the present invention, the terminal sealing member provided on the lid plate welded at the upper end opening of the battery container is provided with the insulating sealing material made of an inorganic material. In the battery in which the terminal material penetrates through and is sealed through, the annular thin portion is provided in a portion that goes around the periphery of the terminal opening and is not in contact with the insulating sealing material. Since the heat conduction can be suppressed, it is possible to avoid damage to the glass hermetic seal, which is an insulating sealing material, due to the heat influence,
It has become possible to realize a highly reliable battery with a high manufacturing yield and a reliable airtightness in the insulating sealing part.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing the structure of a non-aqueous secondary battery of the present invention.

FIG. 2 is an exploded perspective view of a main part of a lid plate assembly.

FIG. 3 is a cross-sectional view of an essential part of an example of the vicinity of the terminal opening of the lid of the non-aqueous secondary battery of the present invention.

FIG. 4 is a cross-sectional view of essential parts of another example of the non-aqueous secondary battery of the present invention near the terminal opening of the lid.

FIG. 5 is a cross-sectional view of a main part of still another example of the non-aqueous secondary battery of the present invention near the terminal opening of the lid.

FIG. 6 is a cross-sectional view of a main part of a conventional non-aqueous secondary battery in the vicinity of a terminal opening of a lid.

[Explanation of symbols]

1,21 Battery container 3 Lid plate assembly 12, 22 Lid plate 13, 25 terminal material 14, 24 glass hermetic seal 15 openings 23 Terminal of cover plate 26 Thin part of lid plate 27 Weld 28 V-shaped groove 29 Multiple U-shaped grooves

Continued front page    F-term (reference) 5H011 AA09 CC06 DD07 DD13 EE04                       FF04 GG09 HH09 KK01                 5H029 AJ15 BJ02 CJ03 CJ04 CJ05                       CJ25 DJ02 DJ14 HJ12

Claims (2)

[Claims] 1. A battery in which a terminal material is sealed by penetrating a terminal opening provided on a lid plate welded at an upper end opening of a battery container through an insulating sealing material made of an inorganic material. A battery characterized in that an annular thin portion is provided on a portion of the plate that surrounds the terminal opening and is not in contact with the insulating sealing material. 2. The battery according to claim 1, wherein a plurality of annular thin portions are provided around the terminal port.