JP2006286586A - Secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery using rivet-shaped components without risk of crack generation when it is processed by cold forging. <P>SOLUTION: The secondary battery comprises gaskets having insulating and sealing properties stacked one another to overlap holes put through the center, lower plates stacked on the outside of them, and a terminal part of a rivet-shaped component whose cylindrical portion projected integrally from the center put into the trough-hole of the lower plate and pressed to fix in the center of a sealing board for sealing an aperture of a housing case in which a wound component of a positive electrode and a negative electrode wound with a separator between them is installed. The rivet component is made of nickel-copper-manganese alloy containing 0.3 wt.% or more of manganese, 0.6 wt.%, 0.1 wt.% or less of copper, and nickel as a residue and its Vickers hardness is 110 or more and 130 or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a secondary battery with improved terminals connected to electrodes.

  Conventionally, a lithium ion secondary battery is configured such that an electrode winding body is housed in a metal rectangular parallelepiped main body case with one end opened, and the opening is sealed with a sealing plate provided with a terminal portion at the center. ing. The sealing plate forms part of the main body case. The terminal portion is composed of a rivet-like member, a gasket, and a lower plate. The electrode wound body is wound after a positive electrode (electrode) made of a lithium metal oxide and a negative electrode (electrode) capable of inserting and extracting lithium are interposed with a separator impregnated with a nonaqueous electrolyte solution interposed therebetween, It is molded into a square.

  In addition, on the sealing plate, insulating and sealing gaskets are overlapped so as to sandwich the sealing plate with a through hole opened in the center. Further, the lower plate is overlapped from the outside, and the cylindrical portion protruding integrally from the central portion of the rivet-like member is inserted into the through hole and the through hole of the lower plate. In this state, the tip of the cylindrical portion is crimped, and the terminal portion is provided on the sealing plate.

  As a result, the rivet-shaped member is insulated from the sealing plate, and the nonaqueous electrolyte inside is sealed. One of the electrodes is connected to the terminal portion thus attached. The other electrode is connected to the main body case. Thereby, it functions as a battery.

  This rivet-like member was made of Ni or a Ni-Cu alloy solid material of Ni 10-60% and Cu 90-40%, which was cold forged and then subjected to heat treatment for the purpose of annealing. The thing is adopted. Since the rivet-like member of the terminal portion is made of a solid material of Ni or Ni—Cu alloy, corrosion resistance and conductivity are ensured, so that the Ni plating process can be omitted. Therefore, there is no fear that the Ni plating peels off from the end of the cylindrical portion deformed by the caulking process, and the electrodes are short-circuited. In addition, since the rivet-shaped member is annealed, work hardening in cold forging, which is a manufacturing process of the rivet-shaped member, is also eased, and a rivet-shaped member having excellent workability in the subsequent caulking process. (For example, see Patent Document 1).

JP 2002-42779 A

However, if a solid material of Ni or Ni 10 to 60% and Cu 90 to 40% Ni-Cu alloy is used as the rivet-like member, when the header is processed by cold forging, the protruding cylindrical portion is likely to crack, There is a problem that the forging process must be proceeded carefully.
Moreover, in order to confirm the presence or absence of a crack, there exists a problem that it takes the man-hour which checks a rivet-like member, and will become an expensive member.

  An object of the present invention is to provide a secondary battery using a rivet-like member that is free from the risk of cracking even by cold forging.

  In the secondary battery according to the present invention, the positive electrode and the negative electrode are opened in the center at the central portion of the sealing plate that seals the opening of the case in which the wound body in which the wound body is wound while holding the separator is held. Insert the gasket with insulation and sealability that overlaps the through holes with each other, the lower plate that overlaps from the outside and the cylindrical part that protrudes integrally from the center part into the through hole and the through hole of the lower plate. In a secondary battery provided with a terminal portion composed of a rivet-like member to be caulked, the rivet member comprises 0.3% by weight or more, 0.6% by weight of manganese, 0.1% by weight or less of copper, and the rest being nickel. And a nickel / copper / manganese alloy having a Bickers hardness of 110 or more and 130 or less.

The effect of the secondary battery according to the present invention is that in the production of the rivet member, the composition of manganese is 0.3 to 0.6% by weight, copper is 0.1% by weight or less, the rest is nickel, and the Bicus hardness is 110. As described above, since a nickel / copper / manganese alloy of 130 or less is used, cracks and the like are not formed in the processed product in the cold forging process. Can be provided.
Further, since the rivet member has a Bickers hardness of 110 or more and 130 or less, the cylindrical portion is securely processed in the caulking process, so that the sealing plate, the gasket, and the lower plate can be reliably integrated.

Embodiment 1 FIG.
1 is a partial perspective view of a lithium ion battery as a secondary battery according to Embodiment 1 of the present invention. FIG. 2 is an exploded perspective view showing an assembled state of the terminal portion according to the first embodiment. FIG. 3 is a cross-sectional view of the terminal portion according to the first embodiment.
As shown in FIG. 1, the lithium ion secondary battery 1 includes an electrode winding body 3 housed in a metal rectangular parallelepiped main body case 2 having one end opened, and a terminal portion 4 is provided at the center of the opening. The sealing plate 5 is hermetically sealed. The sealing plate 5 forms a part of the main body case 2.
As shown in FIG. 3, the terminal portion 4 includes a rivet-like member 12, gaskets 9 and 10, and a lower plate 11. The electrode winding body 3 is wound with a positive electrode (electrode) 6 made of lithium metal oxide and a negative electrode (electrode) 7 capable of occluding and releasing lithium interposed with a separator 8 impregnated with a non-aqueous electrolyte. After that, it is formed into a square.

  In addition, as shown in FIG. 2, the sealing plate 5 is sandwiched between the sealing holes 5a, 9a, and 10a having gaskets 9 and 10 having insulating properties and sealing properties in the center, as shown in FIG. Overlaid. Further, the lower plate 11 is overlapped from the outside, and the cylindrical portion 13 protruding integrally from the central portion of the rivet-like member 12 is inserted into the through holes 5 a, 9 a, 10 a and the through hole 11 a of the lower plate 11. In this state, the tip 14 of the cylindrical portion 13 is crimped, and the terminal portion 4 is provided on the sealing plate 5 as shown in FIG.

  As a result, the rivet-like member 12 is insulated from the sealing plate 5 and the nonaqueous electrolyte inside is sealed. One of the electrodes is connected to the terminal portion 4 attached in this way. The other electrode is connected to the main body case 2. Thereby, it functions as a battery.

  Further, the rivet-like member 12 is made of nickel-containing material having a manganese content of 0.3 to 0.6% by weight, copper of 0.1% by weight or less, the rest being nickel, and a Bickus hardness of 110 to 130. By using a copper / manganese alloy, work hardening in cold forging, which is a manufacturing process of the rivet-shaped member 12, is also eased, and the rivet-shaped member 12 is excellent in workability in the subsequent caulking process.

  In addition, since the rivet member 12 has a Bickus hardness of 110 or more and 130 or less, the cylindrical portion 13 is reliably processed in the caulking process, so that the sealing plate 5, the gaskets 9, 10 and the lower plate 11 are reliably integrated. Can be

Embodiment 2. FIG.
The lithium ion secondary battery as the secondary battery according to the second embodiment of the present invention is different from the lithium ion battery according to the first embodiment in the material of the rivet member. Description is omitted.

In the rivet member according to the second embodiment, a copper / copper alloy of 30 wt% or more and 40 wt% or less, the rest being nickel, and a nickel / copper alloy having a Bickus hardness of 110 or more and 130 or less is obtained by cold forging. Have been made.
Even if a nickel / copper alloy having a copper composition of 30 wt% or more and 40 wt% or less and the rest nickel is used, the cylindrical portion can be caulked by suppressing the Bickus hardness to a range of 110 or more and 130 or less. It is extended uniformly and the sealing plate, gasket, and lower plate can be reliably integrated.

It is a partial perspective view of the lithium ion battery as a secondary battery concerning Embodiment 1 of this invention. FIG. 3 is an exploded perspective view showing an assembled state of the terminal portion according to the first embodiment. FIG. 3 is a cross-sectional view of a terminal portion according to the first embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Lithium ion secondary battery, 2 Main body case, 3 Electrode winding body, 4 Terminal part, 5 Sealing plate, 6 Positive electrode (electrode), 7 Negative electrode (electrode), 8 Separator, 9, 10 Gasket, 11 Lower plate, 12 Rivet-like member, 13 cylindrical part, 14 tip of cylindrical part.

Claims (2)

A through hole opened in the center is overlapped with the center of the sealing plate that seals the opening of the case that houses the wound body in which the positive electrode and the negative electrode are wound while sandwiching the separator. In a secondary battery provided with a gasket, a lower plate stacked from the outside, and a terminal portion made of a rivet-like member that is inserted into the through hole and a through hole of the lower plate by caulking a cylindrical portion integrally protruding from the center portion ,
The rivet member is made of a nickel-containing material in which manganese is 0.3% by weight or more and 0.6% by weight or less, copper is 0.1% by weight or less, the rest is nickel, and the Bickers hardness is 110 or more and 130 or less. A secondary battery comprising a copper-manganese alloy. A through hole opened in the center is overlapped with the center of the sealing plate that seals the opening of the case that houses the wound body in which the positive electrode and the negative electrode are wound while sandwiching the separator. Insulating and sealing gasket, a lower plate stacked from the outside, and a terminal made of a rivet-like member that can be inserted into the through hole and the through hole of the lower plate by caulking a cylindrical portion integrally protruding from the center portion In a secondary battery provided with a portion,
2. The secondary battery according to claim 1, wherein the rivet member is made of a nickel / copper alloy in which copper is 30 wt% or more and 40 wt% or less, the rest is nickel, and the Bickers hardness is 110 or more and 130 or less.

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