JP5076698B2 - battery - Google Patents

Description

  The present invention relates to a battery in which an end portion of an electrode of a power generation element is sandwiched between clip plates and welded together with a lead plate.

  As shown in FIG. 5, a nonaqueous electrolyte secondary battery in which a flat power generation element 1 is housed in a battery case made of flexible aluminum laminate films 2 and 3 has been widely used (for example, Patent Document 1). reference.). The aluminum laminate films 2 and 3 cover the power generating element 1 from above and below and thermally weld the peripheral portion thereof, thereby sealing the inside and forming a battery case.

  The power generating element 1 is formed by winding a belt-like positive electrode 1a and a negative electrode 1b through a separator 1c to make it flat. Moreover, the aluminum foil which is the collector of the positive electrode 1a, and the copper foil which is the collector of the negative electrode 1b are overlapped and protruded at the front and rear ends of the power generation element 1 by winding.

  A positive electrode lead plate 4 and a negative electrode lead plate 5 are connected to the positive electrode 1 a and the negative electrode 1 b of the power generation element 1. These lead plates 4 and 5 are further sealed at the front end portions of the power generating element 1 from the front and rear end faces, and are sealed through the heat-welded aluminum laminate films 2 and 3 to the outside of the battery case. It is designed to protrude.

  The lead plates 4 and 5 are connected by ultrasonic welding with the bases superimposed on the metal foils of the electrodes 1a and 1b protruding from the front and rear ends of the power generating element 1. However, if the lead plates 4 and 5 and the metal foils of the electrodes 1a and 1b are directly ultrasonically welded, the thin metal foil may be broken or the positions of the lead plates 4 and 5 may be shifted and connected.

  Therefore, conventionally, as shown in FIGS. 5 and 6, the lead plates 4 and 5 and the metal foil of the electrodes 1a and 1b are sandwiched between the clip plates 6 and 7, and the clip plates 6 and 7 are viewed from above and below. Ultrasonic welding was performed (in FIG. 6, only the forward positive electrode lead plate 4, the aluminum foil of the positive electrode 1a, and the positive side clip plate 6 are shown). The clip plates 6 and 7 are formed by folding a rectangular metal plate in two, the lower flat first holding plate portions 6a and 7a, the upper flat second holding plate portions 6b and 7b, and these It comprises substantially U-shaped bent portions 6c and 7c that connect the two sandwiching plate portions 6a, 6b, 7a, and 7b. The base portions of the lead plates 4 and 5 and the metal foils of the electrodes 1a and 1b are sandwiched between the two sandwiching plate portions 6a, 6b, 7a and 7b of the clip plates 6 and 7. The leading ends of the lead plates 4 and 5 are slit-like lead plate insertion openings 6d and 7d (lead plate insertion openings) formed at the center of the bent portions 6c and 7c of the clip plates 6 and 7, respectively. The portion 7d is shaded by the clip plate 7 and does not appear in FIG.

  In ultrasonic welding, the first clamping plate portions 6a and 7a of the clip plates 6 and 7 sandwiching the base portions of the lead plates 4 and 5 and the metal foil of the electrodes 1a and 1b are placed on the anvil 8 and The vibration chip 9a attached to the tip of the horn 9 is pressed against the second sandwiching plate portions 6b and 7b to apply ultrasonic vibration.

  However, as described above, the base portions of the lead plates 4 and 5 that are sufficiently thicker than the metal foil and the second portions of the clip plates 6 and 7 are formed through the overlapping of the thin metal foils of the electrodes 1a and 1b. If ultrasonic vibration is applied to the portion where the sandwiching plate portions 6 b and 7 b overlap, there is a possibility that slip occurs between the lead plates 4 and 5 and the clip plates 6 and 7.

For this reason, conventionally, the lead plates 4 and 5 are displaced in the direction indicated by the arrow G in FIG. There has been a problem that the connection between the metal foil of the electrodes 1a and 1b and the clip plates 6 and 7 may be insufficient.
Japanese Patent Laying-Open No. 2005-209587 (second page, FIG. 4)

  The present invention uses a clip plate having an opening in one clamping plate portion, thereby preventing a battery from being displaced between the clip plate and the lead plate during welding. It is something to be offered.

  The invention according to claim 1 is a battery in which the metal foil overlapped at the end portion of the electrode of the power generation element is sandwiched between the clip plates, and the clip plate, the metal foil, and the lead plate are welded. And a second sandwiching plate portion and a substantially U-shaped bent portion connecting the two sandwiching plate portions, and the metal foil is disposed between the two sandwiching plate portions, and the first sandwiching plate An opening is provided in the opening, a lead plate superimposed on the metal foil is exposed in the opening, and the second sandwiching plate, the metal foil, and the lead plate are in the opening. It has been welded in.

  The invention of claim 2 is characterized in that a lead plate insertion opening is provided in the bent portion.

  According to the first aspect of the present invention, the clip plate sandwiches the metal foil of the electrode between the two sandwich plate portions, so that the metal foil of the electrode is bundled and held and securely connected as in the prior art. be able to. Moreover, since the portion where the second clamping plate portion of the clip plate overlaps with the metal foil of the electrode and the base portion of the lead plate is welded through the opening of the first clamping plate portion of the clip plate, The parts where the clip plate and the lead plate directly overlap are no longer welded, and the displacement between the clip plate and the lead plate is prevented and the connection with the metal foil of the electrode is ensured. It can be.

  According to the invention of claim 2, since the lead plate insertion opening for passing the lead plate is formed in the bent portion of the clip plate, the electrode exposed to the opening of the first clamping plate portion of the clip plate When the base portion of the lead plate is superimposed on the metal foil, the lead plate can be reliably positioned.

  Hereinafter, the best embodiment of the present invention will be described with reference to FIGS. In these drawings, the same reference numerals are given to constituent members having functions similar to those of the conventional example shown in FIGS.

  In the present embodiment, a non-aqueous electrolyte secondary battery similar to the conventional example shown in FIG. 5 will be described. As shown in FIG. 1, the power generation element 1 of this non-aqueous electrolyte secondary battery is obtained by winding a strip-like positive electrode 1a and a negative electrode 1b through a separator 1c, and winding it into a cylindrical shape to push the peripheral side surface. It is formed into a flat shape by crushing.

  The positive electrode 1a has a positive electrode active material supported on the surface of a strip-shaped aluminum foil that is a current collector, and the negative electrode 1b has a negative electrode active material supported on the surface of a strip-shaped copper foil that is a current collector. Is. However, the positive electrode 1a is provided with an uncoated portion on which the positive electrode active material is not applied at the front side end portion of the strip-shaped aluminum foil that is long on the left and right, and the negative electrode 1b is behind the strip-shaped copper foil that is long on the left and right. An uncoated portion where the negative electrode active material is not applied is provided at the side end portion. In addition, by shifting the positive electrode 1a to the front side and winding the negative electrode 1b to the rear side, the aluminum foil that is the current collector of the positive electrode 1a is uncoated at the front end portion of the power generation element 1. The copper foil that is the current collector of the negative electrode 1b is exposed at the uncoated portion and protrudes in an overlapping manner from the separator 1c at the rear end.

  The metal foils of the electrodes 1a and 1b protruding at the front and rear ends of the power generating element 1 are sandwiched between the clip plates 6 and 7 and ultrasonically welded together with the lead plates 4 and 5. As shown in FIG. 2, the clip plates 6 and 7 are formed by bending a concave metal plate with a folding axis in the left-right direction, and the flat metal plate portion on the side divided into the concave bifurcation is the first. The flat metal plate portion disposed above the sandwiching plate portions 6a and 7a becomes the second sandwiching plate portions 6b and 7b. The bent metal plates are bent portions 6c and 7c (in FIG. 2, only the front positive-side clip plate 6 is shown). Accordingly, since the first sandwiching plate portions 6a and 7a are the metal plate portions on the side divided into the concave shape, the left and right central portions are cut out, and these portions are the openings 6e and 7e. Become. The clip plate 6 sandwiching the aluminum foil of the positive electrode 1a is made of an aluminum plate or an aluminum alloy plate, and the clip plate 7 sandwiching the copper foil of the negative electrode 1b is made of a copper plate or a copper alloy plate.

  Between the two sandwiching plate portions 6a, 6b, 7a, 7b of the clip plates 6, 7, the metal of the electrodes 1a, 1b projecting at the front and rear ends of the power generating element 1, as shown in FIGS. The foil is sandwiched. At this time, the two sandwiching plate portions 6a, 6b, 7a, 7b of the clip plates 6, 7 are fixed to the metal foil of the electrodes 1a, 1b by pressing from above and below. Here, the overlapping metal foils of the electrodes 1a and 1b are all sandwiched between the clip plates 6 and 7 from above and below, but only a part of the overlapping metal foils may be sandwiched, for example, the upper half of the winding center Only the metal foil may be sandwiched, or only the lower half metal foil may be sandwiched.

  The base portions of the lead plates 4 and 5 are arranged so as to overlap below the metal foils of the electrodes 1a and 1b exposed at the openings 6e and 7e of the first clamping plate portions 6a and 7a of the clip plates 6 and 7, respectively. . Then, as shown in FIG. 3, the bases of the lead plates 4 and 5 are placed on the anvil 8 of the ultrasonic welder, and the vibration tip 9 a attached to the tip of the horn 9 from above is attached to the clip plates 6 and 7. By pressing the second clamping plate portions 6b and 7b and applying ultrasonic vibration, the base portions of the lead plates 4 and 5, the metal foil of the electrodes 1a and 1b, and the second clamping plate portions 6b of the clip plates 6 and 7 are applied. 7b are ultrasonically welded (FIG. 3 shows only the front positive electrode lead plate 4, the positive side clip plate 6 and the aluminum foil of the positive electrode 1a).

  With the above configuration, the clip plates 6 and 7 hold the metal foil of the electrodes 1a and 1b between the upper second holding plate portions 6b and 7b and the lower first holding plate portions 6a and 7a. As in the prior art, the metal foils of these electrodes 1a and 1b can be bundled and held and securely connected. In addition, since the second sandwiching plate portions 6b and 7b of the clip plates 6 and 7 and the metal foil of the electrodes 1a and 1b and the base portions of the lead plates 4 and 5 are ultrasonically welded, the clip is conventionally used. The portion where the plates 6 and 7 and the lead plates 4 and 5 are directly overlapped is no longer ultrasonically welded, and the positional deviation occurs between the clip plates 6 and 7 and the lead plates 4 and 5. Therefore, the connection of the electrodes 1a and 1b to the metal foil can be ensured.

  As shown in FIG. 4, the clip plates 6 and 7 may have lead plate insertion openings 6d and 7d for passing the lead plates 4 and 5 through the bent portions 6c and 7c (see FIG. 4). 4 shows only the front positive-side clip plate 6). In this way, the base portions of the lead plates 4 and 5 are overlapped below the metal foil of the electrodes 1a and 1b exposed at the openings 6e and 7e of the first sandwiching plate portions 6a and 7a of the clip plates 6 and 7, respectively. The leading ends of the lead plates 4 and 5 are projected through the lead plate insertion openings 6d and 7d, so that the positioning of the lead plates 4 and 5 is ensured. Will be able to.

  Moreover, in the said embodiment, although the case where the 1st clamping board parts 6a and 7a of the clip boards 6 and 7 were completely divided into right and left via the opening parts 6e and 7e was shown, for example, it shows in FIG. If it is the clip board 6, the 1st clamping board part 6a divided | segmented into right and left may be connected by the back end part. Moreover, the openings 6e and 7e only need to provide a space for performing ultrasonic welding at the base of the lead plates 4 and 5 below the metal foil of the electrodes 1a and 1b. It may be a hole.

  Moreover, in the said embodiment, although the case where the bending parts 6c and 7c of the clip boards 6 and 7 were curved and folded in two was shown, the folding method is arbitrary, and it can be folded in a more acute shape. Alternatively, the polygon may be folded in half. Furthermore, the clip plates 6 and 7 do not have to have spring elastic force.

  Moreover, although the case where ultrasonic welding was used was shown in the said embodiment, even if it uses other welding methods, it can implement similarly.

  Moreover, in the said embodiment, although the case where it shape | molds in flat shape by winding the electric power generation element 1 in a cylindrical shape and crushing a peripheral side surface was shown, by winding in a long cylindrical shape, an ellipse shape, etc. from the beginning It can also be flat. Furthermore, in the said embodiment, although the flat power generation element 1 was shown, the shape of this power generation element 1 is arbitrary, For example, even if it is the power generation element 1 wound by the cylindrical shape, it can implement similarly. Furthermore, even if this power generation element 1 is a laminated type, it can be similarly implemented.

  Moreover, although the said embodiment demonstrated the nonaqueous electrolyte secondary battery which accommodated the electric power generation element 1 in the aluminum laminate film, the material and shape of a battery case are arbitrary. Furthermore, in the said embodiment, although shown about the nonaqueous electrolyte secondary battery, the kind of battery is also arbitrary.

  The nonaqueous electrolyte secondary battery of the first embodiment using the clip plates 6 and 7 shown in FIGS. 1 to 3 and the nonaqueous electrolyte of the second embodiment using the clip plates 6 and 7 shown in FIG. 200 pieces of secondary batteries and 200 conventional non-aqueous electrolyte secondary batteries using the clip plates 6 and 7 shown in FIGS.

  As a result of comparing the displacement of the lead plates 4 and 5 for the nonaqueous electrolyte secondary batteries of the first and second embodiments and the conventional example, in the conventional example, 20 of the 200 nonaqueous electrolyte secondary batteries are compared. In the first and second embodiments, no misalignment occurs in any of the lead plates 4 and 5 of the 200 non-aqueous electrolyte secondary batteries. It was.

  In addition, with respect to the nonaqueous electrolyte secondary batteries of the first and second examples, the results of comparing the steps of ultrasonic welding the clip plates 6 and 7, the metal foils of the electrodes 1a and 1b, and the lead plates 4 and 5 were compared. In the second embodiment, since the labor for positioning the lead plates 4 and 5 is reduced, the number of man-hours can be reduced by about 20% compared to the first embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a power generation element according to an embodiment of the present invention, in which a lead plate is connected to a metal foil of an electrode using a clip plate. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of the present invention and looking up a clip plate from below. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an embodiment of the present invention, and is a side view illustrating a process of ultrasonically welding a lead plate to a metal foil of an electrode using a clip plate. FIG. 11 is a perspective view showing another embodiment of the present invention, and looking up from below a clip plate in which a lead plate insertion opening is formed. It is a disassembled perspective view of the nonaqueous electrolyte secondary battery which shows a prior art example and accommodated the flat power generation element in the battery case which consists of a flexible aluminum laminate film. It is a side view which shows a prior art example and shows the process of ultrasonically welding a lead board to the metal foil of an electrode using a clip board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power generation element 1a Positive electrode 1b Negative electrode 1c Separator 2 Aluminum laminate film 4 Positive electrode lead plate 5 Negative electrode lead plate 6 Clip plate 6a First clamping plate portion 6b Second clamping plate portion 6c Bending portion 6d Lead plate insertion opening 6e Opening Part 7 Clip plate 7a First clamping plate part 7b Second clamping plate part 7c Bending part 7d Lead plate insertion opening 7e Opening part 8 Anvil 9 Horn 9a Excitation chip

Claims (2)

In the battery in which the metal foil overlapped at the end of the electrode of the power generation element is sandwiched between the clip plates, and the clip plate, the metal foil, and the lead plate are welded,
The clip plate includes a first clamping plate portion, a second clamping plate portion, and a substantially U-shaped bent portion connecting the two clamping plate portions,
The metal foil is disposed between the two sandwich plate portions,
The first clamping plate portion is provided with an opening,
In the opening, a lead plate superimposed on the metal foil is exposed,
The battery, wherein the second holding plate portion, the metal foil, and the lead plate are welded at the opening.   The battery according to claim 1, wherein the bent portion is provided with an opening for inserting a lead plate.

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