JP2001084991A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery having a terminal, capable of facilitating electrical connection and having high sealing performance. SOLUTION: A battery lid unit 2 is composed of a lid plate 3, packing member 4, terminal 5, terminal plate 6, packing member 7 and current collecting washer 8. The terminal 5 is formed of Al or an Al alloy and has a cylindrical upper shaft 51 and a cylindrical lower shaft 52. The terminal plate 6 is formed of stainless steel, Ni-plated stainless steel or Ni-plated Fe, and has a tapered hole 60. The upper shaft 51 of the terminal 5 is inserted into the hole 60 of the terminal plate 6 and crimped. The lower shaft 52 of the terminal 5 is inserted into a hole 82 of the current collecting washer 8 via the packing member 4, a hole 30 of the lid plate 3 and a hole 70 of the packing member 7, and is then crimped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery, and more particularly to a terminal structure.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic devices such as portable radio telephones, portable personal computers, and portable video cameras, lithium ion secondary batteries having high energy density and excellent lightness have been developed. Has been put to practical use.

This lithium ion secondary battery has a maximum capacity of 4.
Since it has a high electromotive force of 1 to 4.2 V, the material of the positive electrode terminal is limited to stainless steel, aluminum, titanium, and the like, which are stable even at a high voltage.

A conventional prismatic lithium ion secondary battery employs a hermetic sealing method as shown in FIG. 6, a metal cover 101 is attached to an upper opening of a metal case 100 by laser welding. The positive electrode terminal 1 is inserted into a hole provided in the center of the metal lid 101.
02 is inserted and sealed by the fusion glass 103. Thus, the hermeticity inside the battery is maintained.

[0005]

However, in the hermetic sealing method as described above, the fused glass 103 is used.
The large positive terminal 102 cannot be attached inside. For this reason, it was difficult to securely attach a current collecting lead to the end of the positive electrode terminal 102 on the inside of the battery.
Further, when the battery is integrated with the protection circuit and the external terminal as a battery pack, it is difficult to attach a lead for connecting the protection circuit and the external terminal to the end of the positive electrode terminal 102 on the outside of the battery. Further, there is a problem that the fused glass 103 is easily broken by a mechanical shock or a thermal shock.

In the case of the hermetic sealing method, the coefficient of thermal expansion of the positive electrode terminal 102 needs to be close to the coefficient of thermal expansion of the fused glass 103. Therefore, the positive electrode terminal 10
As the second material, only titanium or special stainless steel can be used. Titanium and special stainless steel are both expensive and have drawbacks in workability.

Therefore, Japanese Patent Application Laid-Open No. 6-111802,
JP-A-6-111803, JP-A-6-11180
No. 4 and JP-A-6-111805, A
A positive electrode pin for a battery made of 1 or Al alloy and caulked to a battery can or a battery lid has been proposed. Since this battery positive electrode pin uses Al or an Al alloy as a material, it has excellent resistance to electric corrosion and a low manufacturing cost.

[0008] However, Al or Al
Since the alloy is used, it is difficult to securely attach the current collecting lead to the battery positive electrode pin by welding or the like.
It is also difficult to securely attach a lead for electrical connection to a protection circuit and an external terminal to the battery positive electrode pin by welding or the like.

[0009] Therefore, it is an object of the present invention to provide a battery having a terminal that can easily make an electrical connection. It is another object of the present invention to provide a battery which can be easily connected electrically and has a highly sealed terminal.

[0010]

According to the battery of the present invention, a terminal is attached to a battery lid or a battery case, and a terminal plate is attached to an end of the terminal on the outside of the battery by caulking.
A current collecting member is attached to an end of the terminal on the inside of the battery by caulking.

In particular, it is preferable that the terminal is inserted into a hole provided in the battery lid or the battery case via an insulating packing. In addition, the terminal has a cylindrical shaft at the end on the outside of the battery, a circular hole whose diameter gradually decreases in the thickness direction is provided in the terminal plate, and the cylindrical shaft of the terminal is formed in the circular shape of the terminal plate. The cylindrical shaft may be inserted into the hole and swaged to the terminal plate.

Further, the terminal has a cylindrical shaft at the end on the battery inner side, a circular hole is provided in the current collecting member, and the cylindrical shaft of the terminal is inserted into the circular hole of the current collecting member. The cylindrical shaft may be inserted and caulked to the current collecting member.

In particular, it is preferable that the terminal and the current collecting member are made of aluminum or an aluminum alloy.

[0014]

In the battery according to the present invention, since the terminal plate is attached to the end of the terminal on the outside of the battery by caulking, the lead can be easily connected to the terminal plate by welding or the like. Therefore, when the battery is integrated with the protection circuit and the external terminal as a battery pack, electrical connection between the battery terminal and the protection circuit and the external terminal can be reliably and easily performed. In addition, since the current collecting member is attached to the end of the terminal on the battery inner side by caulking, the current collector can be easily joined to the current collecting member by caulking or the like. Therefore, electrical connection between the terminal and the current collector can be reliably and easily performed.

When the terminal is inserted into the hole provided in the battery lid or the battery case via an insulating packing, the hermeticity is maintained even if mechanical shock or heat is applied.

When the terminal has a cylindrical shaft at the end outside the battery and the terminal plate is provided with a circular hole whose diameter gradually decreases in the thickness direction, the end of the shaft is provided. The end of the shaft can be swaged to the terminal plate without much protruding from the terminal plate.

Further, when the terminal has a cylindrical shaft at the end inside the battery and the current collecting member is provided with a circular hole, the end of the shaft can be easily attached to the current collecting member. I can shrug it.

In particular, when the terminal and the current collecting member are made of aluminum or an aluminum alloy, corrosion resistance, workability and lightness are excellent, and the production cost is low.

[0019]

FIG. 1 is a partially cutaway front view of a lithium ion secondary battery according to an embodiment of the present invention.

In FIG. 1, a power generation element (not shown) such as a positive electrode active material, a negative electrode active material, a positive electrode current collector, a separator, and an organic electrolyte is housed in a bottomed prismatic battery case 1 made of, for example, stainless steel. Have been. In this lithium ion secondary battery, for example, LiCoO ₂ as a positive electrode active material,
Carbon having a graphite structure is used as the negative electrode active material, the positive electrode active material is held on a positive electrode current collector made of Al, and the negative electrode active material is held on a negative electrode current collector made of Cu. A separator is arranged between the positive electrode active material and the negative electrode active material, and is filled with an organic electrolyte.

A battery cover unit 2 described later is fitted into the upper opening of the battery case 1. A terminal 5 and a terminal plate 6 are provided at the center of the battery lid unit 2. In the lithium ion secondary battery of FIG.
Is a negative terminal, and the terminal 5 and the terminal plate 6 are positive terminals.

FIG. 2 is a perspective view showing a state before the battery lid unit 2 is assembled. FIG. 3 shows the battery lid unit 2.
It is a figure which shows the state after assembling, (a) is a top view,
(B) is a partially cutaway front view, (c) is a bottom view, and (d) is a side view.

As shown in FIG. 2, the battery cover unit 2
It is composed of a cover plate 3, a packing 4, a terminal 5, a terminal plate 6, a packing 7, and a current collecting washer 8. The cover plate 3 is formed to have a concave cross section, and a hole 30 is provided at the center thereof. As a material of the cover plate 3, stainless steel, Ni-plated stainless steel, Ni-plated Fe, or the like is used. The packing 4 includes a bottomed rectangular tube portion 40 having a concave cross section and a cylindrical portion 41, and a hole 42 connected to the hollow portion of the cylindrical portion 41 is provided at the bottom of the bottomed rectangular tube portion 40. The packing 4 is integrally formed of a resin such as polypropylene or polyethylene.

The terminal 5 is integrally formed as a rivet comprising a quadrangular prism-shaped main body 50, a cylindrical upper shaft 51, and a cylindrical lower shaft 52. As a material of the terminal 5,
Al or an Al alloy is used. The terminal plate 6 is formed in a substantially hexagonal shape, and a hole 60 is provided at the center thereof.
The inner wall of the hole 60 is tapered so that its diameter gradually decreases in the thickness direction. As a material of the terminal plate 6,
Stainless steel, Ni-plated stainless steel, Ni-plated Fe, and the like are used.

The packing 7 is formed in a plate shape from a resin such as polypropylene or polyethylene. A hole 70 is provided in the packing 7. The current-collecting washer 8 includes a bent horizontal plate 80 and a vertical plate 81, and the horizontal plate 80 is provided with a hole 82. As a material of the current washer 8, Al or an Al alloy is used similarly to the terminal 5.

When assembling the lid unit 2, the upper shaft 51 of the terminal 5 is inserted into the hole 60 of the terminal plate 6, and the lower shaft 52 and the main body 50 of the terminal 5 are respectively connected to the cylindrical portion 41 of the packing 4 and the bottomed corner. The cylindrical portion 41 of the packing 4 is inserted into the hole 30 of the cover plate 3 and the packing 7.
Of the terminal 5 protruding from the cylindrical portion 41 of the packing 4 and the hole 8 of the current washer 8 in the lower shaft 52 of the terminal 5.
Insert 2. Then, the upper shaft 51 of the terminal 5 is connected to the terminal plate 6.
And the lower shaft 52 of the terminal 5 is swaged with respect to the current washer 8. Thereby, the battery lid unit 2 as shown in FIG. 3 is assembled. A positive electrode current collector (not shown) is joined to the vertical plate 81 of the current washer 8 by caulking or the like.

Here, the structure of the terminal 5 and a method for caulking the terminal 5 will be described in detail. FIG. 4 is a cross-sectional view of the terminal 5, and FIG. 5 is a cross-sectional view showing a state where the terminal 5 is swaged to the terminal plate 6 and the current washer 8.

As shown in FIG. 4, the terminal 5 is
A solid upper shaft 51 is integrally formed on the upper surface of the main body 50.
A lower shaft 52 having a hollow portion 53 is integrally formed on the lower surface of the lower shaft 52. The upper shaft 51 of the terminal 5 is connected to the hole 60 of the terminal plate 6 (FIG. 2).
5), and the upper shaft 51 can be swaged to the terminal plate 6 as shown in FIG. In this case, the hole 6 of the terminal plate 6
Since the inner wall 61 of 0 is tapered, the terminal 5 is securely fixed to the terminal plate 6 even if the head of the upper shaft 51 is formed in an arc shape and the projecting portion on the terminal plate 6 is reduced. Can be.

Further, the lower shaft 52 of the terminal 5 is inserted into the hole 82 (see FIG. 2) of the current washer 8 via the packing 4 and the end of the lower shaft 52 is crushed so that the terminal 5 is crushed.
Can be swaged to the current washer 8. In this case, since the lower shaft 52 has a cylindrical shape having the hollow portion 53, the end of the lower shaft 52 can be easily swaged to the current washer 8.

In the lithium ion secondary battery of this embodiment,
As shown in FIG. 3, the terminal 5 is provided with the terminal plate 6 having a large area, so that leads can be easily connected to the terminal plate 6. Particularly, the terminal plate 6 is made of stainless steel, N
Since it is made of i-plated stainless steel, Ni-plated Fe, or the like, it is possible to easily spot weld a lead made of a Ni plate. Therefore, when this lithium ion secondary battery is integrated as a battery pack together with a protection circuit and external terminals,
Electrical connection between the terminal 5 and the protection circuit and the external terminal can be reliably and easily made.

Further, since the current washer 8 is attached to the terminal 5, the positive electrode current collector can be easily joined to the current washer 8 by caulking or the like. Therefore, electrical connection between the terminal 5 and the positive electrode current collector can be reliably and easily made.

Further, since the terminal 5 and the current collecting washer 8 are formed of Al or an Al alloy, the corrosion resistance, the workability and the lightness are excellent, and the manufacturing cost is low.

The packing 4 is provided between the terminal 5 and the cover plate 9.
Is provided, the sealing property and insulating property are high, and the sealing property is maintained even when mechanical shock or heat is applied.

In the lithium ion secondary battery of this embodiment, as shown in FIG. 3, an oval gas discharge hole 31 is provided in the cover plate 3. Gas release hole 31 of lid plate 3
A metal sheet 9 is disposed on the upper surface, and the holding plate 1 is further disposed thereon.
0 is arranged. The metal sheet 9 is formed of a nickel annealing material by rolling to a thickness of about 30 μm. A groove 90 is formed in the metal sheet 9 by etching. The thickness of the groove 90 is 5 μm, and the shape of the portion surrounded by the groove 90 is similar to the gas discharge hole 31 and has a slightly smaller oval shape. The holding plate 10 is made of stainless steel and has an oval through hole 11. After spot welding the four corners of the holding plate 10, the holding plate 10
The outer peripheral portion of the through hole 11 is laser-welded to form a laminated body including the cover plate 3, the thin metal plate 9, and the pressing plate 10. This laminated body constitutes a safety valve mechanism. Therefore, safety is ensured while maintaining hermeticity.

The power generating elements are not limited to those of the above embodiment. The positive electrode active material may be any material capable of dedoping or doping lithium ions. In addition to lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium chromium oxide, lithium vanadium oxide, lithium molybdenum An oxide, lithium molybdenum disulfide, lithium titanium oxide, lithium titanium sulfide, or the like, or a composite compound of these can be used. Further, as the negative electrode active material, metallic lithium, lithium alloy, or a carbonaceous material that can be doped or undoped with lithium ions, for example, graphite, pyrolytic carbon, pitch coke, needle coke,
Petroleum coke, calcined organic polymer (phenolic resin,
Furan resin, a fired body such as polyacrylomitrile) or the like can be used.

Further, as an electrolyte in the organic electrolyte,
Is LiClO_Four, LiAsF₆, LiPF₆, LiB
F_Four, CH_ThreeSO_ThreeLi, CF_ThreeSO_ThreeLi, (CF_Three
SO _Two)_TwoAny one of lithium salts such as NLi or
A mixture of two or more can be used. Organic electricity
As a solvent in the dissolution, for example, propylene carbohydrate
, Ethylene carbonate, dimethyl carbonate
G, diethyl carbonate, methyl ethyl carbonate
G, 1,2-dimethoxyethane, 1,2-diethoxye
Tan, γ-butyrolactone, tetrahydrofuran, 2-
Methyltetrahydrofuran, 1,3-dioxolan,
Ruphoran, methylsulfolane, acetonitrile, propyl
Onitrile, methyl formate, ethyl formate, methyl acetate, vinegar
Either one or two or more such as ethyl acid
Can be used. Polyester is used as a separator.
Microporous membrane of polyolefin such as styrene and polypropylene
One or two or more kinds of laminated films, polyolefins,
Nonwoven fabric such as polyester, polyamide, cellulose, etc.
Use a monolayer or a laminated membrane with the above microporous membrane
Can be. Particularly preferred is a polyethylene microporous membrane.
Used.

In the above embodiment, the case where the present invention is applied to a prismatic secondary battery has been described. However, the present invention can be similarly applied to a cylindrical secondary battery. Further, the present invention is not limited to a lithium ion secondary battery, and can be applied to other lithium secondary batteries and lithium primary batteries having an organic solvent.

Further, in the above embodiment, the main body 50 of the terminal 5 is formed in the shape of a quadrangular prism.
Is not limited to that of the above embodiment, and may be formed, for example, in a columnar shape. In that case, the packing 4 is also connected to the terminal 5
Is formed in a shape corresponding to. Further, in the above embodiment, the terminal plate 6 is formed in a hexagon, but the shape of the terminal plate 6 is not limited to that of the above embodiment, and may be other polygons, circles,
It may be formed in an elliptical shape or another shape.

[0039]

As described above, according to the present invention, there is provided a battery having a terminal which can easily perform electrical connection. Further, when an insulating packing is used, a terminal having a high sealing property can be obtained. Furthermore, when the terminal and the current collecting member are formed of aluminum or an aluminum alloy, a battery having a terminal with high corrosion resistance, excellent workability and light weight, and low production cost can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a lithium ion secondary battery according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state before the battery lid unit is assembled.

FIG. 3 is a plan view, a partially cutaway plan view, a bottom view, and a side view showing a state after the battery lid unit is assembled.

FIG. 4 is a sectional view of a terminal.

FIG. 5 is a cross-sectional view showing a state in which the terminal is swaged to a terminal plate and a current-collecting washer.

FIG. 6 is a cross-sectional view of a conventional prismatic lithium ion secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery case 2 Battery cover unit 3 Cover plate 4 Packing 5 Terminal 6 Terminal plate 7 Packing 8 Washer for current collection 30, 42, 60, 70, 82 Hole 51 Upper shaft 52 Lower shaft In each figure, the same numerals are the same or the same. The corresponding parts are shown.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01M 10/40 H01M 10/40 Z

Claims (5)

[Claims] 1. A terminal is attached to a battery lid or a battery case, a terminal plate is attached by caulking to an end of the terminal outside the battery, and a current collecting member is caulked to an end of the terminal inside the battery. A battery characterized by being attached by: 2. The battery according to claim 1, wherein the terminal is inserted into a hole provided in the battery lid or the battery case via an insulating packing. 3. The terminal has a cylindrical shaft at an end on the outside of the battery, and the terminal plate has a circular hole whose diameter gradually decreases in a thickness direction. The battery according to claim 1, wherein a columnar shaft is inserted into the circular hole of the terminal plate, and the columnar shaft is caulked to the terminal plate. 4. The terminal has a cylindrical shaft at an end inside the battery, a circular hole is provided in the current collecting member, and the cylindrical shaft of the terminal is connected to the current collecting terminal. The battery according to claim 1, wherein the cylindrical shaft is inserted into the circular hole of the member for use and the cylindrical shaft is caulked to the terminal plate. 5. The battery according to claim 1, wherein the terminal and the current collecting member are made of aluminum or an aluminum alloy.