JP2000311664A - Nonaqueous electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a large battery with an effective sealing structure by forming annular or circular edge sections on the upper face of a flange section and the lower face of a battery lid, providing an insulating elastic member between the edge sections, and allowing the edge sections to bite into the surfaces of the insulating elastic member. SOLUTION: A positive electrode current collecting terminal 1 is provided with a male screw section 25 formed with a thread groove screwed to a nut 20 on a tip outer periphery and a flange section 41 supporting a lower packing 21 serving as an insulating elastic member and fastened to the lower face of a stainless battery lid 8 by the nut 20 via the lower packing 21. A circular lug 40 smaller in diameter than the flange section 41 is formed integrally with the flange section 41 on the upper face of the flange section 41. A circular edge section corresponding to the lug 40 is formed on the lower face of the battery lid 8, and a recess corresponding to the upper face of the flange section 41 is formed on the lower face of the outer periphery of the edge section of the battery lid 8. A staircase-like cross section of the edge section, recess and lower face is formed on the lower face of the battery lid 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte battery, and more particularly, to a positive and negative electrode external collector fixed to a battery cover and electrically connected to an external load from an electrode group housed in a battery case. The present invention relates to a non-aqueous electrolyte battery provided with a power terminal.

[0002]

2. Description of the Related Art Conventionally, aqueous secondary batteries such as lead-acid batteries and nickel-cadmium batteries have been mainly used as secondary batteries which are widely used in general. However, these aqueous secondary batteries have a drawback that the energy density is low because an operation voltage exceeding the decomposition potential of water cannot be obtained. Therefore, recently, research and development of non-aqueous electrolyte batteries represented by lithium secondary batteries have been actively conducted. This non-aqueous electrolyte battery has a high operating voltage, a high energy density, and excellent cycle characteristics, so that the electric capacity is 1.5%.
Energy saving as well as small Ah consumer small batteries
From the viewpoint of environmental protection, it is expected to be applied to high-voltage, high-energy-density, high-output large batteries used for electric power storage and electric vehicles.

However, in a non-aqueous electrolyte battery, it is necessary to strictly prevent water from entering the battery, and the airtightness of the battery is more important than that of an aqueous solution. Small consumer batteries are hermetically sealed by a caulking mechanism between the lid that also serves as an external current collecting terminal and the battery case. However, a large battery whose electric capacity exceeds 5 Ah has a large area of the caulking part, so the airtightness by the caulking mechanism is large. Is difficult to maintain, and the battery capacity is large, so the output current value is large, and it is necessary to use the external current collecting terminal independently.The sealed structure near the external current collecting terminal is also highly reliable. There is a problem peculiar to large batteries, such as the need to

For this reason, in a large non-aqueous electrolyte battery, for example, as disclosed in Japanese Patent Application Laid-Open No. 9-922248, a battery container and a lid are hermetically sealed by laser welding, and the periphery of an external current collecting terminal is closed. A structure using a ceramic washer or an O-ring was common.

[0005]

However, when a ceramic washer is used in the above-described conventional structure for sealing the external current collecting terminal portion, pores are easily formed because the ceramic is a sintered body of an inorganic oxide. The surface has irregularities due to the pores, and the gas passes through the irregularities. Further, there is a problem that the ceramic washer breaks unless the flatness of the washer contact surface is high. For these reasons, the ceramic washer can maintain the insulation between the lid and the external current collecting terminal, but it is difficult to maintain the hermetic seal with the ceramic washer itself. In addition, the O-ring swells due to heat or contact with the non-aqueous electrolyte, so that what was initially sealed cannot be kept sealed. Therefore, when an O-ring is used, a member having a function on the outside of the O-ring only to predict the swelling of the O-ring and to prevent deformation due to the swelling of the O-ring is required. However, the O-ring cannot maintain insulation between the lid and the external current collecting terminal. Therefore, in the conventional hermetic structure near the external current collecting terminal, the hermetic seal is maintained by using a ceramic washer and an O-ring, and an accessory for maintaining the function thereof, so that the number of parts increases and the work becomes complicated. There was a problem.

The present invention has been made in view of the above circumstances, and has as its object to improve the working efficiency by reducing the number of parts near the external current collecting terminal and to provide a sealed structure particularly effective for a large nonaqueous electrolyte battery. And

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a positive electrode and a negative electrode which are fixed to a battery cover and electrically connected to an external load from an electrode group housed in a battery case. In a non-aqueous electrolyte battery provided with a current collecting terminal, the external current collecting terminal has a flange portion whose diameter is enlarged at a lower side of the battery lid and a male screw portion threaded at a tip of the external current collecting terminal. The nut and the flange portion are fastened to the battery lid using a nut screwed into the male screw portion, and an annular or circular edge portion is formed on the upper surface of the flange portion and the lower surface of the battery lid. Is formed, an insulating elastic member is interposed between the edge portions, and the edge portion cuts into the surface of the insulating elastic member. In the present invention, the nut and the flange portion are tightened by the nut, and the edge portions formed on the upper surface of the flange portion and the lower surface of the battery cover bite into the insulating elastic member, so that the insulating elastic member functions as a seal. I do. Therefore,
Sealing near the battery lid to which the external current collecting terminal is fixed can be ensured.

In this case, the upper surface of the flange portion has a convex portion, the lower surface of the battery lid has a concave portion, and the convex portion and the concave portion are fitted and sealed via the insulating elastic member. According to this configuration, the insulating elastic member is sandwiched between the fitting concave and convex portions, and the concave and convex portions bite into the surface of the insulating elastic member, so that the hermetically sealed state can be improved. Furthermore, if the insulating elastic member is made of PFA resin, the PFA resin has elasticity, and is excellent in insulation, compression resistance, non-swelling, and heat resistance, and requires use of ceramic washers, O-rings, and additional parts. In addition, since the hermetic seal near the battery cover to which the external current collecting terminal is fixed can be maintained, the number of components can be reduced. Further, a non-circular concave portion similar to the outer shape of the flange portion is formed on the lower surface of the battery lid, and the concave portion and the flange portion are fitted via the insulating elastic member. Since the position of the external current collecting terminal is fixed, the electrically conductive connection from the electrode group is fixed. If the battery cover is provided with a projection for fixing the position of the external current collecting terminal, the position of the external current collecting terminal can be fixed without forming a concave portion on the lower surface of the battery cover as in the invention according to claim 4. Therefore, the battery lid can be made thinner by the amount of forming the concave portion, and the weight of the battery lid can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of a nonaqueous electrolyte battery to which the present invention is applied will be described below with reference to the drawings.

(Structure) As shown in FIGS. 3A and 3B, the nonaqueous electrolyte battery of the present embodiment has an electrode group as a power generation element. In the electrode group, a plurality of positive electrode plates 5 and negative electrode plates 6 are provided with separators 9 so that the two electrode plates do not directly contact each other.
Are laminated through. Since the positive electrode plate 5 is disposed outside the electrode group, the number of the positive electrode plates 5 is stacked one more than the number of the negative electrode plates 6. A positive electrode lead 3 and a negative electrode lead 4 are drawn out from each of the positive electrode plate 5 and the negative electrode plate 6, respectively. The positive electrode lead 3 and the negative electrode lead 4 are overlapped with each other to form a positive current collecting terminal 1 and a negative current collecting terminal 1 as external current collecting terminals. It is welded to the lower part of the terminal 2.

As shown in FIG. 1, the positive electrode current collecting terminal 1 supports a male screw part 25 having a thread groove for screwing with a nut 20 at the outer periphery of the tip and a lower packing 21 as an insulating elastic member. The lower surface of the battery cover 8 made of stainless steel has a flange portion 41 which is fastened to the battery cover 8 by the nut 20 via the lower packing 21. On the upper surface of the flange portion 41, a circular (cylindrical) convex portion 40 having a smaller diameter than the flange portion 41 is formed integrally with the flange portion 41. On the other hand, a circular edge portion is formed on the lower surface of the battery lid 8 corresponding to the convex portion 40, and a concave portion is formed on the outer peripheral lower surface of the edge portion of the battery lid 8 corresponding to the upper surface of the flange portion 41. Have been. Therefore, the lower surface of the battery lid 8 has a stepped cross section of the edge portion, the concave portion, and the lower surface. Further, when the convex portion 40 and the flange portion 41 are tightened by the nut 20, the concave portion including the edge portion is configured to fit with the convex portion 40 and the flange portion 41 via the lower packing 21.
In the present embodiment, the height of the projection 40 and the depth of the edge of the battery lid 8 are each set to 0.5 mm. The lower packing 21 is made of PFA resin, and has a circular insertion hole formed in the center so that the upper side of the projection 40 of the positive electrode current collector terminal 1 can be inserted. On the upper surface of 41, the upper surface has a stepped cross-sectional shape sandwiched between the edge portion, the concave portion and the lower surface of the battery lid 8.

On the other hand, an upper packing 22 made of PFA resin is arranged on the upper surface of the battery cover 8 in contact with the battery cover 8. The upper packing 22 has a cylindrical projection protruding downward, the tip of which abuts against the lower packing 21, in order to insulate between the battery lid 8 and the positive electrode current collecting terminal 1. An insertion hole is formed at the center so that the upper side of the projection 40 of the electrical terminal 1 can be inserted. Between the nut 20 and the upper packing 22, a wave washer 24 and a flat washer 23 are sequentially inserted from the top of the positive electrode current collector 1 and arranged. The positive electrode current collecting terminal 1 includes a lower packing 21, a battery lid 8, an upper packing 22, a flat washer 23, and a wave washer 2, which are arranged on the upper surfaces of the protrusion 40 and the flange 41 in order from the bottom.
4 is fastened to the battery cover 8 by a nut 20 screwed with a male screw portion 25.

As shown in FIG. 2, the outer shape of the flange portion 41 is hexagonal, and the outer shape of the lower packing 21 is also hexagonal in conformity with the shape of the flange portion 41. Also, as shown in FIGS.
A rectangular elongated lead weld extends from the lower surface in the lower direction, and the positive electrode lead 3 is welded to the lead weld as described above. Note that the negative electrode current collecting terminal 2 side has the same structure as the positive electrode current collecting terminal 1 side.

In order to fabricate the nonaqueous electrolyte battery of this embodiment, the positive electrode lead 3 and the negative electrode lead 4 are welded to the lead welding portions of the external current collecting terminals, respectively, and then the nut 20 is attached to the external current collecting terminal.
The electrode group is inserted into a battery can 7 as a stainless steel battery case while tightening with a torque of kgf / cm to secure the airtightness around the external current collecting terminal. Next, the opening into which the electrode group is inserted is sealed with the battery lid 8. In the present embodiment,
Since a stainless steel material was used for the battery can 7 and the battery lid 8, the opening was sealed by laser welding.

Then, 6 mol / l of a mixed solvent of ethylene carbonate and dimethyl carbonate is added at a ratio of 1 mol / l.
An electrolyte in which lithium fluorophosphate (LiPF ₆ ) is dissolved is injected from an injection hole (not shown) formed in the battery cover 8, and the injection hole is sealed to produce a nonaqueous electrolyte battery having a sealed structure. be able to.

(Operation) Next, the operation of the nonaqueous electrolyte battery according to the present embodiment will be described.

In the electrode group of this embodiment, a plurality of positive plates 5 and negative plates 6 are laminated with the separator 9 interposed therebetween as described above. Then, the positive electrode lead 3 and the negative electrode lead 4 are pulled out from each electrode plate, and each lead is overlapped and each is welded to each external current collecting terminal. Therefore, the welding surface of the lead welding portion of each external current collecting terminal is always laminated. It must be arranged in a fixed direction parallel to the direction. Therefore, the external current collecting terminal
The position needs to be fixed with respect to the electrode group. In the non-aqueous electrolyte battery of the present embodiment, as shown in FIG. 2, the outer shape of the flange portion 41 is hexagonal, and a concave portion similar to this hexagonal shape is formed on the lower surface of the battery lid 8 to form the flange portion 41. The position of each external current collecting terminal is fixed by fitting into the concave portion.

The lower packing 21 is made of PFA resin and the PFA resin is an insulating material, so that each external current collecting terminal and the battery cover 8 are insulated. Further, since the PFA resin has elasticity, the edge of the battery cover 8 bites into the surface of the lower packing 21, and the lower packing 21 is formed between the convex portion 40 and the flange portion 41 of each external current collecting terminal and the battery cover 8. The seal is engaged between the recess including the edge portion. Further, since the lower packing 21 is fixed to the battery lid 8 by tightening the nut 20, it is necessary to sufficiently withstand the compressive force at the time of the tightening, but the PFA resin has a sufficient function in this respect. . In addition, since the lower packing 21 is disposed inside the battery and thus comes into contact with the non-aqueous electrolyte, the PFA resin does not swell even in long-term contact with the non-aqueous electrolyte and can maintain insulation and hermeticity. it can. Furthermore, since the PFA resin has heat resistance, the PFA resin can sufficiently withstand the heat generated by the external current collecting terminals during high-rate discharge.

Since the upper packing 22 is also made of PFA resin and made of an insulating material, it insulates between each external current collecting terminal and the battery cover 8 and between the flat washer 23 and the battery cover 8. Since the upper packing 22 is fixed to the battery cover 8 by tightening the nut 20, it is necessary to sufficiently withstand the compressive force when tightened, but the PFA resin has a sufficient function as described above.

(Second Embodiment) Next, a second embodiment of the nonaqueous electrolyte battery to which the present invention is applied will be described. In the present embodiment, the outer shape of the flange portion is non-circular as in the first embodiment, but the shape is different. In the following embodiments, the same members as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted. Only different points will be described.

In this embodiment, as shown in FIG. 4, the external shape of the flange portion 41 of each external current collecting terminal is partially circular, and a concave portion similar to the partial circular flange portion 41 is formed on the lower surface of the battery lid 8. The concave portion has a flange portion 4
1 are fitted, and the position of each external current collecting terminal is fixed.
In addition, the outer shape of the lower packing 21 is also partially circular by conforming to the shape of the flange portion 41. Thus, the position of each external current collecting terminal is also fixed according to the second embodiment.

(Third Embodiment) Next, a third embodiment of the nonaqueous electrolyte battery to which the present invention is applied will be described. In this embodiment, the outer shape of the flange portion is circular.

As shown in FIGS. 5 and 6, in the nonaqueous electrolyte battery according to the present embodiment, a press-fit hole is formed in the battery cover 8, and a cylindrical external current collecting terminal for fixing the position of the press-fit hole. Are fixed to the battery lid 8 by press-fitting and welding. The outer shape of the flange portion 41 is circular, and a substantially rectangular flat plate portion extends from the flange portion 41 in the direction of the press-fit hole of the battery lid 8. An insertion hole into which the projection 30 projecting downward from the battery lid 8 is formed through an insulating member 31 that insulates the projection 30 from the flat portion of the flange portion 41. The insulating member 31 has a substantially concave cross-sectional shape that covers the protrusion 30 and is made of PFA resin.

The fixing position of each external current collecting terminal is determined by inserting the projection 30 through the insulating member 31 into the insertion hole formed in the flat plate extending from the flange 41.
In the present embodiment, after the protrusion 30 was press-fitted into the press-fit hole of the battery cover 8, the boundary between the protrusion 30 and the battery cover 8 was laser-welded from the outside of the battery. The projection 30 was made of a stainless material for laser welding. As described above, the position of each external current collecting terminal is also fixed according to the present embodiment in which the outer shape of the flange portion is circular.

(Effects, etc.) Next, the non-aqueous electrolyte battery of the above-described embodiment, together with the battery disclosed in Japanese Patent Application Laid-Open No. 9-922248, is used for sealing and insulating near the external current collecting terminal. The required number of parts was checked.

As a result, in the non-aqueous electrolyte batteries of the first to third embodiments, the number of parts required for sealing and insulating near the external current collecting terminal is seven in the battery of JP-A-9-92248. (According to previous reports, 6 poles (external collector terminal, lower packing, upper packing, flat washer, wave washer, nut) less than poles, backup ring, seal, ceramic butting, ring, ceramic washer, nut Sealing and insulation could be secured with the number of parts.

In the first and second embodiments, the flange 4
1 has a non-circular outer shape, a concave portion similar to the flange portion 41 is provided on the battery lid 8, and the flange portion 41 is fitted to the battery lid 8, whereby the protrusion 30 and the insulating member 3 are formed.
It is possible to determine the position of the external current collecting terminal without providing 1, and it is possible to reduce the number of parts while maintaining the airtightness.

On the other hand, in the third embodiment, the flange 41
It is not necessary to provide a concave portion similar to the outer shape of the flange portion 41 in the battery cover 8 as compared with the case where the battery cover 8 is fitted to the cover 8, so that the battery cover 8 can be made thinner, and the weight corresponding to that can be reduced. It is possible to do.

Therefore, in the above embodiment, the working efficiency can be improved by reducing the number of parts for ensuring insulation and sealing near the external current collector, and a large nonaqueous electrolyte battery can be used. The necessary closed structure can be secured.

In the above embodiment, the example in which the convex portion 40 is formed on the flange portion 41 side is described. However, if an edge portion is formed, the convex portion may be formed on the battery lid 8 side.

In the above embodiment, the convex portion 40 is formed in a circular shape. However, a part of the convex portion on the male screw portion 25 side may be formed in a (circular) ring shape having the same height as the flange portion 41.
In this case, the shapes of the battery lid 8 and the lower packing 21 need to be adapted to the (circular) annular convex portion according to the shape of the convex portion. Since the number of steps increases, the sealed state of the nonaqueous electrolyte battery can be further improved.

Further, in the above embodiment, the upper packing 2
2 and the lower packing 21 are made into two parts, but if the upper packing and the lower packing are integrated, the number of parts can be further reduced.

It is needless to say that the present invention is not limited to the above-described embodiment, but can adopt various other configurations without departing from the gist of the present invention.

[0034]

As described above, according to the present invention,
The nut and the flange portion are tightened by the nut,
The edges formed on the upper surface of the flange portion and the lower surface of the battery lid bite into the insulating elastic member, so that the insulating elastic member functions as a seal, so that the hermetic seal near the battery lid to which the external current collecting terminal is fixed can be ensured. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially enlarged side view of the vicinity of a battery cover of a positive electrode current collecting terminal of a nonaqueous electrolyte battery according to a first embodiment to which the present invention is applied.

FIG. 2 is a partially enlarged view of the vicinity of a flange portion of the nonaqueous electrolyte battery according to the first embodiment when viewed from an electrode group side.

3A is a partially cutaway side view of the negative electrode current collecting terminal side of the battery can of the nonaqueous electrolyte battery of the first embodiment, and FIG. 3B is a partially cutaway side of the positive electrode current collector terminal side of the battery can. It is a side view.

FIG. 4 is a partially enlarged view of the vicinity of a flange portion of a nonaqueous electrolyte battery according to a second embodiment when viewed from an electrode group side.

FIG. 5 is a partially enlarged side view of the vicinity of a battery cover of a positive electrode current collecting terminal of a nonaqueous electrolyte battery according to a third embodiment.

FIG. 6 is a partially enlarged view of the vicinity of a flange portion of a nonaqueous electrolyte battery according to a third embodiment when viewed from an electrode group side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive current collecting terminal 2 Negative current collecting terminal 7 Battery can (battery case) 8 Battery lid 20 Nut 21 Lower packing (insulating elastic member) 22 Upper packing 30 Projection 31 Insulating member 40 Convex part 41 Flange part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuru Koseki 2-8-7 Nihonbashi Honcho, Chuo-ku, Tokyo Inside Shin-Kobe Electric Machinery Co., Ltd. (72) Mikio Oguma 2-87 Nihonbashi Honcho, Chuo-ku, Tokyo F term in Shin Kobe Electric Co., Ltd. (reference) 5H011 AA09 BB03 CC06 DD11 EE04 FF04 GG02 HH02 JJ04 JJ27

Claims (5)

[Claims] 1. A non-aqueous electrolyte battery comprising: a positive electrode and a negative electrode external current collecting terminal fixed to a battery lid and electrically connected to an electrode group and housed in a battery case and connected to an external load; The current collecting terminal has a flange portion enlarged in diameter on the lower side of the battery lid and a male screw portion threaded at the tip of the external current collecting terminal, and the nut is screwed into the male screw portion using a nut. And the flange portion are fastened to the battery lid, and an annular or circular edge portion is formed on an upper surface of the flange portion and a lower surface of the battery lid, and an insulating elastic member is interposed between the edge portions. Wherein the edge portion cuts into the surface of the insulating elastic member. 2. The battery device according to claim 1, wherein a convex portion is provided on an upper surface of the flange portion, a concave portion is provided on a lower surface of the battery lid, and the convex portion and the concave portion are fitted and sealed via the insulating elastic member. The non-aqueous electrolyte battery according to claim 1. 3. The non-aqueous electrolyte battery according to claim 1, wherein the insulating elastic member is a PFA resin. 4. A non-circular concave portion similar to the outer shape of the flange portion is formed on the lower surface of the battery cover, and the concave portion and the flange portion are fitted via the insulating elastic member. 4. One of claims 1 to 3, characterized in that:
Non-aqueous electrolyte battery according to the item. 5. The non-aqueous electrolyte battery according to claim 1, wherein the battery cover has a projection for fixing the position of an external current collecting terminal.