JP2013114816A - Power storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage element which can prevent a fixing piece in a current collector secured to a case from being broken under exposure to vibration.SOLUTION: A power storage element according to the present invention includes current collectors which are housed in a case together with a power generation element and which are fixed in place by shaft-like members inserted into the case. The current collectors each include a fixing piece disposed along the inner face of the case and a power generation element connection part which is electrically and mechanically connected to the power generation element. The fixing piece includes a base piece connected to the power generation element connection part and a fold-back piece connected to the base piece. The base piece is disposed closer to the case side than the fold-back piece. The fold-back piece is folded back toward the inside of the case and laid on top of the base piece. The shaft-like members fasten the fixing piece while being inserted into the case, the base piece, and the fold-back piece to the case.

Description

  The present invention provides an output terminal in which a power generation element and a current collector electrically connected to the power generation element are accommodated in a case, and the current collector is fixed to the case and arranged outside the case The present invention relates to a power storage element that is electrically connected to the storage element.

  In recent years, chargeable / dischargeable storage elements have been adopted as power sources for various devices. In the present specification, the “storage element” is a concept including both a battery (such as a lithium ion battery and a nickel metal hydride battery) and a capacitor (such as an electric double layer capacitor).

  Such a storage element includes a power generation element including a positive electrode plate and a negative electrode plate, and a pair of current collectors each electrically connected to a corresponding polarity electrode plate of the positive electrode plate and the negative electrode plate in the power generation element, A case containing a power generation element and a pair of current collectors, a pair of output terminals arranged on the outside of the case, and each of the pair of current collectors is fixed to a corresponding polarity current collector A pair of shaft-shaped members, each of which includes a pair of shaft-shaped members that electrically connect a current collector of a corresponding polarity and an output terminal of a corresponding polarity (see, for example, Patent Document 1).

  In this type of power storage element, the positive electrode plate and the negative electrode plate that constitute the power generation element are arranged with a relative displacement in the first direction. Thus, a positive electrode lead portion in which only the positive electrode plate is laminated is formed at one end portion of the power generation element in the first direction. A negative electrode lead portion in which only the negative electrode plate is laminated is formed at the other end portion of the power generation element in the first direction.

  Each of the pair of current collectors includes a fixing piece disposed along the inner surface of the case, and a power generation element connection portion extending from the fixing piece. The fixing piece is formed in a flat plate shape. The fixing piece is provided with a through hole through which the shaft-like member is inserted. The power generation element connection portion of one current collector of the pair of current collectors is electrically and mechanically connected to the positive electrode lead portion of the power generation element in a state of being disposed along the power generation element. On the other hand, the power generation element connection portion of the other current collector of the pair of current collectors is electrically and mechanically connected to the negative electrode lead portion of the power generation element in a state of being disposed along the power generation element. ing.

  Each of the pair of shaft-shaped members generates an axial force in a state where the pair of shaft-shaped members are inserted through the fixing pieces of the current collector of the corresponding polarity of the pair of current collectors and the case. That is, one shaft-shaped member of the pair of shaft-shaped members sandwiches the fixing portion of the one current collector and the case from inside and outside while being inserted into the case, and the one current collector The case is fastened. On the other hand, the other shaft-shaped member of the pair of shaft-shaped members sandwiches the fixing piece portion of the other current collector and the case from inside and outside while being inserted into the case, and the other current collector The body and case are fastened.

  And the external side of the case in each of the pair of shaft-like members is electrically connected to the corresponding output terminal of the pair of output terminals. Thereby, the electrical storage element of the said structure is comprised so that the electric power from an electric power generation element can be supplied to a pair of output terminal via a pair of electrical power collector.

JP 2003-346770 A

  By the way, in this kind of electricity storage element, the power generation element is supported by a pair of current collectors fixed to the case. Therefore, when a vibration is applied from the outside, the power generation element tries to swing in the case. Along with this, the current collector connected to the power generation element also tries to swing. As a result, repeated stress is generated in the fixing piece of the current collector. More specifically, the current collector is fixed to the case in a state where the fixing piece and the case receive a tightening force (fastening force) of the shaft-shaped member. For this reason, the fixing piece around the shaft-shaped member serves as a support point (bending fulcrum) of the current collector. As a result, when the current collector is swung together with the power generating element, stress is repeatedly generated in the fixing piece around the shaft-shaped member.

  For this reason, when the power storage element is adopted as a power source of a device that generates vibration during driving (for example, various devices such as a hybrid electric vehicle (HEV), an electric vehicle (EV), an electric motorcycle, an aircraft, a ship). There is a possibility that the fixing part of the electric body may be damaged by fatigue.

  Therefore, an object of the present invention is to provide a power storage element that can prevent a fixing piece in a current collector fixed to a case from being damaged due to vibration.

The electricity storage device according to the present invention is:
A power generation element including a positive electrode plate and a negative electrode plate;
A pair of current collectors each electrically connected to a corresponding one of the positive electrode plate and the negative electrode plate in the power generation element;
A case containing the power generation element and the pair of current collectors;
A pair of output terminals disposed outside the case;
Each of the pair of current collectors is a pair of shaft-like members that fix a corresponding current collector of the pair of current collectors to the case in a state where each of the current collectors is inserted into the case. A pair of shaft-shaped members that electrically connect a corresponding current collector and a corresponding output terminal of the pair of output terminals;
Each of the pair of current collectors is
A fixing piece disposed along the inner surface of the case;
A power generation element connection portion extended from the fixing piece, the power generation element connection portion electrically and mechanically connected to the power generation element,
The fixing piece of at least one of the pair of current collectors is:
A base piece having a first end and a second end, wherein the first end is connected to the power generation element connection,
A folded piece portion having a first end portion and a second end portion, the first end portion comprising a folded piece portion connected to the base piece portion;
The base piece portion is disposed closer to the case than the folded piece portion,
The folded piece portion is folded to the inner side of the case at the first end portion of the folded piece portion and overlapped with the base piece portion,
At least one of the pair of shaft-shaped members is fastened to the case with the fixing piece in a state of being inserted through the case, the base piece, and the folded piece. .

  According to the electricity storage device of the present invention, at least one of the pair of current collectors (fixing piece) is fixed to the case at the case, the base piece, and the folded piece. It will be in the state laminated | stacked toward the inner side from the outer side. Therefore, the current collector is fixed to the case in a state in which the folded piece portion and the case in the fixing piece portion receive the tightening force (fastening force) of the shaft-like member. Accordingly, the folded piece portion around the shaft-shaped member of the base piece portion and the folded piece portion constituting the fixing piece portion serves as a support point (bending fulcrum) of the current collector. Along with this, when the current collector is swung together with the power generation element, repeated stress accompanying the vibration is generated in the folded piece portion constituting the fixing piece portion. On the other hand, intermittent bending accompanying swinging does not act intensively on the base piece portion sandwiched between the case and the folded piece portion, and the occurrence of repeated stress is suppressed.

  Thereby, damage to the base piece continuous with the power generation element connecting portion is prevented. Therefore, the current collector fixed to the case can be maintained in a state where the output terminal and the power generation element are mechanically and electrically connected.

  Then, the first end portion of the folded piece portion is connected to the base piece portion, so that the whole fixing piece portion has an integral structure. Therefore, the power storage element can protect the current collector while suppressing an increase in the number of parts and an increase in assembly man-hours.

  As one aspect of the present invention, the second end of the folded piece is disposed so as to overlap the first end of the base piece, and at least the base at the second end of the folded piece. The edge on one side is preferably chamfered. In this way, it is possible to reliably prevent the base piece portion of the current collector from being damaged in the vicinity of the second end portion of the folded piece portion.

  Specifically, the fixing piece portion of at least one of the pair of current collectors has a double structure in which the base piece portion and the folded piece portion are polymerized. For this reason, when the power generating element is about to swing, the base piece of the current collector tends to bend around the base piece portion side edge at the second end of the folded piece portion. Therefore, if the edge is sharp, a local bending stress may act on the base piece, which may damage the base piece. However, since the edges are chamfered, local bending stress does not act on the base piece. Therefore, breakage of the fixing piece (base piece) in the current collector is reliably prevented.

  In this case, the second end portion of the base piece portion is an end portion on the opposite side of the first end portion of the base piece portion, and the first end portion of the folded piece portion is the base piece portion. It is preferable that the second end portion of the folded piece portion is connected to the second end portion and is located on the opposite side of the folded end portion from the first end portion.

  In this way, when a bending load is applied to the fixing piece of the current collector, the bending stress can be distributed to the base piece and the folded piece. That is, since the base piece portion and the folded piece portion constituting the fixing piece portion are separated from each other, the base piece portion and the folded piece portion can each independently receive a bending load. Therefore, when a bending load is applied to the fixing piece, the bending stress can be distributed to the base piece and the folded piece. Thereby, the said electrical storage element can prevent more reliably the damage of the piece part for fixation.

  As described above, the power storage device of the present invention can have an excellent effect that the fixing piece in the current collector fixed to the case can be prevented from being damaged by the influence of vibration.

FIG. 1 is an overall perspective view of a power storage device according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the energy storage device according to the embodiment. FIG. 3 is a partial enlarged cross-sectional view of the energy storage device according to the embodiment, and is a partial cross-sectional view of the periphery of a fixing piece of the current collector. FIG. 4 is a partially exploded perspective view of the energy storage device according to the embodiment as viewed obliquely from above. FIG. 5 is a partially exploded perspective view of the energy storage device according to the embodiment as viewed obliquely from below.

  Hereinafter, a power storage device according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the present embodiment, a lithium ion battery (hereinafter simply referred to as a battery) will be described as an example of a power storage element.

  As shown in FIGS. 1 and 2, the battery according to the present embodiment corresponds to the power generation element 2 including the positive electrode plate 20 a and the negative electrode plate 20 b, and each of the positive electrode plate 20 a and the negative electrode plate 20 b in the power generation element 2. A pair of current collectors 3, 3 electrically connected to a polar plate, a case 4 housing the power generation element 2 and the pair of current collectors 3, 3, and a pair of electrodes disposed outside the case 4 Output terminals 5 and 5, and a pair of shaft-like members 6 and 6 that fix the current collector 3 to the case 4 while being inserted through the case 4.

  The power generation element 2 further includes a separator 20c having electrical insulation in addition to the positive electrode plate 20a and the negative electrode plate 20b. The positive plates 20a and the negative plates 20b are alternately stacked with the separator 20c interposed therebetween. In the present embodiment, the positive electrode plate 20a, the negative electrode plate 20b, and the separator 20c are each formed in a strip shape. The positive electrode plate 20a, the negative electrode plate 20b, and the separator 20c are overlapped in a state in which the longitudinal directions are matched, and are wound in the longitudinal direction.

  The positive electrode plate 20a and the negative electrode plate 20b are arranged in a state of being relatively displaced in the first direction. In the present embodiment, the positive electrode plate 20a and the negative electrode plate 20b are arranged in a state of being relatively displaced in a direction orthogonal to the longitudinal direction (winding center direction corresponding to the first direction). Thus, a positive electrode lead portion 21 in which the positive electrode plate 20a is laminated is formed at one end portion of the power generation element 2 in the first direction, and a negative electrode plate 20b is formed at the other end portion of the power generation element 2 in the first direction. Stacked negative electrode lead portions 21 are formed.

  In the present embodiment, the power generation element 2 is formed in a flat shape. Accordingly, the power generating element 2 includes a pair of flat portions 22 and 22 that extend straight on both sides of the winding center (center line extending in the first direction), and a pair of arcs that connect the pair of flat portions 22 and 22 to each other. Parts 23 and 23. Accordingly, the flat portions 22 and 22 at one end portion of the power generation element 2 in the winding center direction are used as the positive electrode lead portion 21, and the flat portions 22 and 22 at the other end portion of the power generation element 2 in the winding center direction are the negative electrode. The lead portion 21 is used.

  One current collector 3 (referred to as a positive electrode current collector) 3 of the pair of current collectors 3 and 3 is formed by bending a metal plate. As shown in FIGS. 3 to 5, the positive electrode current collector 3 includes a fixing piece 30 disposed along the inner surface of the case 4, and a power generation element connecting portion 31 extending from the fixing piece 30. And.

  The fixing piece 30 includes a base piece 300 having a first end P1 and a second end P2, and a folded piece 301 having a first end P3 and a second end P4.

  The base piece 300 is formed in a flat plate shape (in the present embodiment, a strip shape) having a substantially rectangular shape in plan view. The first end portion P <b> 1 of the base piece 300 is connected to the power generation element connection portion 31. The base piece 300 is disposed on the case 4 side with respect to the folded piece 301. In the present embodiment, the second end portion P <b> 2 of the base piece portion 300 is an end portion on the opposite side of the first end portion P <b> 1 of the base piece portion 300.

  The folded piece portion 301 is formed in a substantially rectangular flat plate shape (in the present embodiment, a strip shape) in plan view. The first end portion P <b> 3 of the folded piece portion 301 is connected to the base piece portion 300. The second end portion P4 of the folded piece portion 301 is an end portion on the opposite side of the first end portion P3 of the folded piece portion 301. In the present embodiment, the first end portion P <b> 3 of the folded piece portion 301 is connected to the second end portion P <b> 2 of the base piece portion 300. The folded piece portion 301 is folded back to the inside of the case 4 at the first end portion P3 of the folded piece portion 301. As a result, the folded piece 301 is overlapped with the base piece 300 on the inner side of the case 4. Accordingly, the second end portion P4 of the folded piece portion 301 is disposed so as to overlap the first end portion P1 side of the base piece portion 300. At least the base piece 300 side edge of the second end P4 of the folded piece 301 is chamfered. Here, the chamfering means that the edge is cut off. Therefore, the surface formed by cutting off the edge may be a flat surface or a curved surface (curved surface).

  A through hole 302 for inserting the shaft-like member 6 is formed in the fixing piece 30. That is, the overlapping base piece 300 and the folded piece 301 are provided with through holes 302 having the same concentricity and the same diameter.

  As shown in FIGS. 4 and 5, the power generation element connection portion 31 has a first end portion P5 and a second end portion P6. The first end portion P1 of the base piece 300 is connected to the first end portion P5 of the power generation element connection portion 31. And the electric power generation element connection part 31 has comprised the right angle or the substantially right angle with respect to the piece 30 for fixing (base piece part 300). The power generation element connection portion 31 is formed in the longitudinal direction in the direction in which the first end portion P5 and the second end portion P6 are arranged. And the electric power generation element connection part 31 is arrange | positioned along the electric power generation element 2 (positive electrode lead part 21) in the 2nd direction (direction orthogonal to the winding center of the electric power generation element 2) orthogonal to a 1st direction. A connection piece 310 is formed between the first end portion P5 and the second end portion P6 of the power generation element connection portion 31 for electrical and mechanical connection with the power generation element 2.

  The connection piece 310 is configured to be insertable into the winding center portion of the power generation element 2. In the present embodiment, the connection piece 310 is spaced in the third direction (direction perpendicular to the winding center direction of the power generation element 2 and the major axis direction of the power generation element 2) perpendicular to the first direction and the second direction. Two are provided. The two connection pieces 310 and 310 are formed to extend in the second direction. The two connection pieces 310 and 310 are formed so as to extend in the same direction as the fixing piece 30.

  The connection piece 310 is electrically and mechanically connected to the positive electrode lead portion 21 in the vicinity in a state where the connection piece 310 is inserted into the winding center of the power generation element 2. Since the power generation element 2 according to the present embodiment is formed in a flat spiral shape, as shown in FIG. 2, the positive electrode lead portion 21 is gathered by a clip member 32 (thin plate folded in half). It is caught. The connection piece 310, the clip member 32, and the lead portion 21 are integrally coupled. Thereby, the positive electrode lead portion 21 is connected to the current collector 3 via the clip member 32 so as to be energized.

  The other of the pair of current collectors 3 and 3 (referred to as a current collector for negative electrode) 3 is formed in the same form as the current collector for positive electrode (one current collector) 3. Therefore, the above description regarding the positive electrode current collector 3 is a description of the negative electrode current collector 3 by replacing “positive electrode” in the text with “negative electrode”. Accordingly, the description of the positive electrode current collector 3 is substituted for the individual description of the negative electrode current collector 3.

  In the positive electrode current collector 3, the connection piece 310 is inserted into the winding center of one end portion of the power generation element 2 in the first direction so that the fixing piece portion 30 extends to the negative electrode current collector 3 side. The Then, the connection piece 310, the clip member 32, and the positive electrode lead portion 21 of the positive electrode current collector 3 are integrally connected. In the negative electrode current collector 3, the connection piece 310 is inserted into the winding center of the other end of the power generation element 2 in the first direction so that the fixing piece 30 extends toward the positive electrode current collector 3. Is done. Then, the connection piece 310, the clip member 32, and the negative electrode lead portion 21 of the negative electrode current collector 3 are integrally connected.

  The case 4 includes a case main body 40 having an opening 400 formed on one surface, and a lid 41 that closes the opening 400 of the case main body 40.

  The case main body 40 is formed so as to be able to accommodate the positive electrode current collector 3 and the negative electrode current collector 3 connected to the power generation element 2 together with the power generation element 2. The case body 40 includes a bottom portion 401 having a quadrangular shape in plan view, a pair of side wall portions 402 and 402 erected from both ends of the bottom portion 401 in the longitudinal direction, and a pair of front and rear walls erected from both ends orthogonal to the longitudinal direction of the bottom portion 401. Sections 403 and 403. Adjacent side wall portions 402 and front and rear wall portions 403 are connected to each other. As a result, an opening 400 corresponding to the planar shape of the bottom 401 is formed in the case body 40. In the present embodiment, the power generation element 2 is accommodated in the case body 40 through the opening 400 so that the front and rear wall portions 403 and 403 and the flat portions 22 and 22 of the power generation element 2 face each other.

  The lid 41 is formed corresponding to the planar shape of the opening 400 of the case body 40. The lid body 41 is provided with a pair of through holes 410 and 410 for inserting the shaft-like member 6 at intervals. In the present embodiment, as described above, the power generating element 2 is accommodated in the case body 40 with the flat portion 22 facing the front and rear wall portions 403. Therefore, the positive electrode current collector 3 and the negative electrode current collector 3 connected to the power generation element 2 are arranged with an interval in the direction in which the side wall portions 402 and 402 are arranged. Accordingly, the pair of through holes 410 and 410 provided in the lid body 41 are arranged with a space in the direction in which the side wall portions 402 and 402 are arranged.

  The outer periphery of the lid 41 is welded to the upper end portion of the case body 40 (the upper ends of the side wall portions 402 and 402 and the front and rear wall portions 403 and 403). Thereby, the lid body 41 seals the opening 400 of the case main body 40.

  Each of the pair of output terminals 5 and 5 is a portion connected to an electrical load or another battery. One output terminal (hereinafter, referred to as positive electrode output terminal) 5 of the pair of output terminals 5 and 5 is formed in a shaft shape. More specifically, as shown in FIGS. 3 to 5, the positive electrode output terminal 5 includes a shaft-like terminal portion 50 and a rotation stop portion 51 continuous with the terminal portion 50. The positive electrode output terminal 5 is provided with a screw groove on the outer periphery of the terminal portion 50 to which a female screw member (for example, a nut) (not shown) can be screwed. That is, in the present embodiment, a bolt terminal is employed for the positive output terminal 5.

  As shown in FIGS. 3 and 4, the rotation-preventing portion 51 has a rotation-preventing groove 510 that extends in a direction perpendicular to the axial direction of the terminal portion 50 on the surface opposite to the connection surface with the terminal portion 50. I have. In the present embodiment, the rotation stop portion 51 is formed to have a larger diameter than the terminal portion 50. In addition, the stop portion 51 is sized so as to be housed in a recess 53 formed in a stop member 52 described later.

  Here, the rotation stop member 52 is provided corresponding to the positive electrode output terminal 5. The locking member 52 is a synthetic resin molded product having electrical insulation. In the present embodiment, a recess 53 for accommodating the stop portion 51 is formed on the upper surface of the stop member 52. A convex portion 54 that can be fitted into the groove 510 formed in the locking portion 51 is formed in the inner portion (on the bottom surface) of the concave portion 53 of the locking member 52.

  And the lower surface (surface on the opposite side of the open part of the recessed part 53) of the rotation stop member 52 is adhere | attached on the outer surface of case 4 (lid 41). As a result, the rotation-preventing member 52 is prevented from rotating about the axis extending in the direction orthogonal to the outer surface of the lid body 41. Accordingly, the positive electrode output terminal 5 fitted to the rotation member 52 and the convex portion 54 is prevented from rotating.

  The other output terminal (hereinafter referred to as negative output terminal) 5 of the pair of output terminals 5 and 5 is formed in the same form as the positive output terminal 5 (one output terminal) (see FIG. 2). . Therefore, the above description regarding the positive electrode output terminal 5 is a description of the negative electrode output terminal 5 by replacing “positive electrode” in the text with “negative electrode”. Accordingly, the description of the positive output terminal 5 is substituted for the individual description of the negative output terminal 5 here.

  One of the pair of shaft-like members 6 and 6 (hereinafter, referred to as a positive electrode shaft-like member) 6 includes a shaft-like rivet portion 60 and a flange portion 61 connected to the rivet portion 60. I have. In the positive electrode shaft member 6 according to the present embodiment, another rivet portion (hereinafter referred to as a connecting rod rivet portion) 62 is connected to a portion of the flange portion 61 opposite to the portion connected to the rivet portion 60. Yes.

  The rivet portion 60 of the positive electrode shaft-like member 6 is inserted from the outside of the case 4 into the through hole 410 of the case 4 and the through hole 302 of the fixing piece 30 of the positive electrode current collector 3. And the front-end | tip part of the rivet part 60 is caulked in the case 4. As a result, the case 4 (the lid body 41) and the fixing piece 30 (the base piece 300 and the folded piece 301) are crimped to the flange 61 of the positive electrode shaft-like member 6 and the tip of the rivet 60 that has been caulked. And are in a state of being fastened to each other.

  The other of the pair of shaft-like members 6 and 6 (hereinafter referred to as a negative electrode shaft-like member) 6 is formed in the same form as the positive electrode shaft-like member 6 (see FIG. 2). The attachment mode of the negative electrode shaft-like member 6 is the same as that of the positive electrode shaft-like member 6. Therefore, the above description regarding the positive electrode shaft-shaped member 6 is a description of the negative electrode shaft-shaped member 6 by replacing “positive electrode” in the text with “negative electrode”. In connection with this, the description regarding the positive electrode shaft-shaped member 6 is substituted for description of the negative electrode shaft-shaped member 6 and the attachment mode of the negative electrode shaft-shaped member 6 here.

  Returning to FIG. 2, the battery 1 includes a pair of internal gaskets arranged along the inner surface of the lid body 41 of the case 4 so as to correspond to the respective arrangements of the positive electrode current collector 3 and the negative electrode current collector 3. And a pair of external gaskets 8, 8 disposed along the outer surface of the lid 41 of the case 4 so as to correspond to the respective arrangements of the positive electrode current collector 3 and the negative electrode current collector 3. It has.

  One of the pair of internal gaskets 7 and 7 (hereinafter, referred to as positive electrode internal gasket) 7 is a synthetic resin molded product having electrical insulation and sealing properties. In the present embodiment, the positive electrode internal gasket 7 is formed in a rectangular shape in plan view as shown in FIGS. Further, a concave portion 70 that can receive the fixing piece 30 of the positive electrode current collector 3 is formed on one surface of the positive electrode internal gasket 7 (the surface opposite to the surface along the inner surface of the lid body 41). (See FIG. 3 and FIG. 5). Further, a through hole 71 is formed in the positive electrode internal gasket 7. The through hole 71 is provided so as to coincide with the through hole 302 formed in the fixing piece 30 in a state where the fixing piece 30 of the positive electrode current collector 3 is received in the recess 70. .

  The other internal gasket (hereinafter referred to as negative electrode internal gasket) 7 of the pair of internal gaskets 7 and 7 is formed in the same form as the positive electrode internal gasket 7 (see FIG. 2). Therefore, the above description regarding the internal gasket 7 for the positive electrode is a description of the internal gasket 7 for the negative electrode by replacing “positive electrode” in the sentence with “negative electrode”. Accordingly, the description of the positive electrode internal gasket 7 is substituted for the individual description of the negative electrode internal gasket 7.

  One of the pair of external gaskets 8, 8 (hereinafter referred to as positive electrode external gasket) 8 is a synthetic resin molded product having electrical insulation and sealing properties, similar to the positive electrode internal gasket 7. . The positive external gasket 8 has a size that is slightly larger than the flange 61 of the positive shaft member 6. The positive external gasket 8 is formed with a recess 80 that can receive the flange 61 of the positive shaft member 6.

  The positive external gasket 8 has a through hole 81 through which the rivet portion 60 of the positive electrode shaft member 6 can be inserted in a state where the flange portion 61 of the positive electrode shaft member 6 is accommodated in the recess 80. Yes. A cylindrical portion 82 concentric with a through hole 81 through which the rivet portion 60 of the positive electrode shaft-like member 6 is inserted is provided on the lower surface of the positive electrode external gasket 8. The cylindrical portion 82 can be inserted into the rivet portion 60 of the positive electrode shaft-like member 6 through an inner hole (not numbered). The cylindrical portion 82 is inserted into the through hole 410 of the lid body 41 and the through hole 71 of the positive electrode internal gasket 7 connected to the through hole 410.

  The other external gasket (hereinafter referred to as negative electrode external gasket) 8 of the pair of external gaskets 8 and 8 is formed in the same form as the positive electrode external gasket 8 (see FIG. 2). Therefore, the above description regarding the positive electrode external gasket 8 is a description of the negative electrode external gasket 8 by replacing “positive electrode” in the text with “negative electrode”. Accordingly, the description of the positive external gasket 8 is substituted for the individual description of the negative external gasket 8.

  Thus, the battery 1 of this embodiment includes a pair of shaft-like members (positive-electrode shaft-like member, negative-electrode shaft-like member) 6, 6 and a pair of output terminals (positive electrode output terminal, negative electrode output terminal) 5. , 5 are independent from each other. On the premise of this, each battery 1 has a corresponding polar shaft member 6 of the pair of shaft members 6 and 6, and a pair of output terminals 5 and 5, as shown in FIG. A pair of connecting rods 9 and 9 are provided for electrically connecting the output terminals 5 having the polarities.

  That is, the battery 1 includes a connection rod (hereinafter referred to as a positive electrode connection rod) 9 that electrically connects the positive electrode output terminal 5 and the positive electrode shaft member 6, and the negative electrode output terminal 5 and the negative electrode shaft member. 6 is provided with a connecting rod (referred to as a negative electrode connecting rod) 9 for electrically connecting to 6.

  The positive electrode connecting rod 9 is formed of a strip-shaped metal plate as shown in FIGS. The positive electrode connection rod 9 is formed with two through holes 90 and 91 (hereinafter, one through hole is referred to as a first hole 90 and the other through hole is referred to as a second hole 91) with an interval in the longitudinal direction. Has been. The connecting rod rivet portion 62 of the positive electrode shaft-like member 6 is inserted into the first hole 90 of the positive electrode connecting rod 9. The tip end portion of the connecting rod rivet portion 62 protruding outward from the positive electrode connecting rod 9 is caulked (see FIG. 3).

  On the other hand, the terminal portion 50 of the positive output terminal 5 is inserted into the second hole 91 of the positive connection rod 9. Then, a female screw member (not shown) is screwed into the terminal portion 50 of the positive electrode output terminal 5 and tightened, so that the rotation stopping portion 51 of the positive electrode output terminal 5 and the positive electrode connecting rod 9 come into contact with each other. As a result, the positive electrode output terminal 5 is electrically connected to the positive electrode current collector 3 via the positive electrode connecting rod 9 and the positive electrode shaft member 6.

  On the premise of this, the rivet portion 60 of the positive electrode shaft-shaped member 6 includes a positive electrode outer gasket 8 (through holes 81 and a cylindrical portion 82) and a positive electrode collector disposed in the concave portion 70 of the positive electrode inner gasket 7. It is continuously inserted into the fixing piece 30 (through hole 302) of the electric body 3. In the rivet portion 60 of the positive electrode shaft-like member 6, the tip portion protruding inward from the positive electrode current collector 3 (fixing piece portion 30) is caulked (see FIG. 3).

  Thus, the positive electrode current collector 3 is electrically connected to the positive electrode shaft-like member 6 while being fixed to the case 4. At the same time, the positive shaft member 6 presses the positive inner gasket 7 and the positive outer gasket 8 against the inner and outer surfaces of the lid 41 and compresses and deforms the cylindrical portion 82 of the positive outer gasket 8 ( The diameter is increased in the radial direction). Thereby, the space between the rivet portion 60 and the inner peripheral surface defining the through hole 410 of the lid body 41 is sealed.

  The negative electrode connecting rod 9 is formed in the same form as the positive electrode connecting rod 9 (see FIG. 2). The connection mode between the negative electrode connection rod 9 and the negative electrode current collector 3 is the same as the connection mode between the positive electrode connection rod 9 and the positive electrode current collector 3 (see FIG. 2). Therefore, the above description regarding the positive electrode connection rod 9 is a description of the negative electrode connection rod 9 by replacing “positive electrode” in the text with “negative electrode”. In connection with this, the description regarding the connection rod 9 for negative electrodes is substituted for the separate description of the connection rod 9 for negative electrodes, and the connection aspect of the collector electrode 9 for negative electrodes, and the collector 3 for negative electrodes here.

  The battery 1 according to the present embodiment is as described above. According to the battery 1, as shown in FIG. 2, the case 4, the base piece 300, and the folded piece 301 are stacked from the outside to the inside at the fixed position of the positive electrode current collector 3. .

  Therefore, the positive electrode current collector 3 is fixed to the case 4 in a state in which the folded piece portion 301 and the case 4 in the fixing piece portion 30 receive the tightening force (fastening force) of the shaft-like member 6. Therefore, the folded piece portion 301 constituting the fixing piece portion 30 of the positive electrode current collector 3 is a support position of the positive electrode current collector 3.

  Along with this, intermittent bending due to oscillation (vibration) acts intensively on the folded piece portion 301 (around the through hole 302) of the positive electrode current collector 3 around the positive electrode shaft member 6. Repeated stress will be generated. On the other hand, the base piece 300 of the positive electrode current collector 3 is sandwiched between the case 4 and the folded piece 301. Therefore, intermittent bending due to swinging does not concentrate on the base piece portion 300 of the positive electrode current collector 3 around the positive electrode shaft-like member 6, and the occurrence of repeated stress is suppressed. .

  As a result, in the positive electrode current collector 3, even if the folded piece 301 constituting the fixing piece 30 is damaged (fatigue failure) due to the influence of vibration, the base piece 300 that is continuous with the power generation element connecting portion 31 Damage is prevented. Therefore, the positive electrode current collector 3 can be maintained in a state in which the positive electrode output terminal 5 and the power generation element 2 are mechanically and electrically connected without fatigue failure even in a vibration environment. .

  Moreover, the form and attachment aspect of the negative electrode collector 3 are the same as the form and attachment aspect of the positive electrode collector 3. Therefore, even in the fixing position of the negative electrode current collector 3, the case 4, the base piece 300, and the folded piece 301 are stacked from the outside to the inside. As a result, the same action as that of the positive electrode current collector 3 occurs also in the negative electrode current collector 3. Therefore, the negative electrode current collector 3 can be maintained in a state in which the negative electrode output terminal 5 and the power generation element 2 are mechanically and electrically connected without fatigue failure even in a vibration environment. .

  In each of the positive electrode current collector 3 and the negative electrode current collector 3, the first end portion P <b> 1 of the folded piece portion 301 is connected to the base piece portion 300, so that the entire fixing piece portion 30 is integrally formed. become. Therefore, the battery 1 can protect the positive electrode current collector 3 and the negative electrode current collector 3 while suppressing an increase in the number of components and an increase in assembly man-hours.

  Further, in each of the positive electrode current collector 3 and the negative electrode current collector 3, the base piece portion 300 can be reliably prevented from being damaged in the vicinity of the second end portion P4 of the folded piece portion 301.

  More specifically, the fixing piece 30 in each of the positive electrode current collector 3 and the negative electrode current collector 3 has a double structure in which the base piece portion 300 and the folded piece portion 301 are polymerized. Therefore, when the power generating element 2 is about to swing, the base piece 300 is the base piece 300 at the second end P2 of the folded piece 301 in each of the positive current collector 3 and the negative current collector 3. It tends to bend around the side edge as a fulcrum. Therefore, if the edge is sharp, a local bending stress may act on the base piece 300, and the base piece 300 may be damaged. However, since the edge is chamfered, the local bending stress does not act on the base piece 300. Therefore, in each of the positive electrode current collector 3 and the negative electrode current collector 3, the base piece 300 is reliably prevented from being damaged.

  Further, in each of the positive electrode current collector 3 and the negative electrode current collector 3, an impact force due to vibration and a load of the power generation element 2 acted as a bending load on the fixing piece 30 via the power generation element connection portion 31. At this time, the bending stress can be dispersed in the base piece 300 and the folded piece 301. That is, since the base piece part 300 and the folded piece part 301 constituting the fixing piece part 30 are separated from each other, the base piece part 300 and the folded piece part 301 can independently receive a bending load. Therefore, when acting as a bending load on the fixing piece 30, the bending stress can be distributed to the base piece 300 and the folded piece 301. Thereby, the battery 1 can more reliably prevent the fixing piece 30 from being damaged.

  In addition, the electrical storage element which concerns on this invention is not limited to the said embodiment, Of course, it can add a change suitably in the range which does not deviate from the summary of this invention.

  In the said embodiment, although the lithium ion battery was mentioned as an example of an electrical storage element, an electrical storage element is not limited to a lithium ion battery. For example, the storage element may be another battery such as a nickel metal hydride battery or a capacitor (such as an electric double layer capacitor).

  In the above embodiment, each fixing piece 30 of the pair of current collectors 3 and 3 includes the folded piece 301. However, the present invention is not limited to this. For example, only the fixing piece 30 of the current collector 3 of any one of the pair of current collectors 3 and 3 may include the folded piece 301. In general, in a lithium ion battery, the positive electrode current collector 3 is often made of aluminum, and the negative electrode current collector 3 is often made of copper. In such a case, the positive electrode current collector 3 made of aluminum is more easily damaged by the action of stress than the negative electrode current collector 3 made of copper. Therefore, as described above, when only the fixing piece 30 of the current collector 3 of one of the pair of current collectors 3 and 3 includes the folded piece portion 301, the positive electrode current collector 3 is fixed. It is preferable that the use piece part 30 is provided with the folding piece part 301.

  Although the folded piece part 301 of the said embodiment was made into the single layer by being formed in the flat plate of a substantially square shape in planar view, it is not limited to this. For example, the folded piece portion 301 may be folded twice or more inside the case 4.

  The edge on the base piece portion 300 side in the second end portion P4 of the folded piece portion 301 of the above embodiment is chamfered, but is not limited to this. For example, the edge on the base piece portion 300 side in the second end portion P4 of the folded piece portion 301 may be unprocessed.

  Although the fixing piece 30 of the above embodiment does not connect the entire opposing surface of the base piece 300 and the folded piece 301, the present invention is not limited to this. For example, the base piece 300 and the folded piece 301 may be connected (welded or the like) between the insertion position of the shaft member 6 and the second end P2 of the base piece 300.

  In the said embodiment, although the output terminal 5 and the shaft-shaped member 6 were electrically connected via the connection rod 9, it is not limited to this. For example, the output terminal 5 and the shaft-like member 6 may be integrally formed.

  In the said embodiment, although the rotation stop member 52 and the external gasket 8 were set as the independent structure, it is not limited to this. For example, only the external gasket 8 having a function of preventing the output terminal 5 from rotating may be disposed on the outer surface of the case 4.

  In the above embodiment, the shaft-like member 6 including the rivet portion 60 to be caulked is used, but the present invention is not limited to this. For example, even if the shaft-like member 6 having a male screw portion screwed into a screw hole formed in the fixing piece portion 30 or a female screw member arranged on the inner surface side of the fixing piece portion 30 is employed. Good. Also in this case, the shaft-like member 6 fastens the fixing piece 30 to the case 4 while being inserted through the case 4, the base piece 300 and the folded piece 301. Therefore, even if the shaft-like member 6 having a male screw portion is employed, the same operations and effects as in the above embodiment can be achieved.

  In the above embodiment, each of the pair of output terminals 5 and 5 arranged on the outer side of the case 4 is composed of the same type of bolt terminals, but the present invention is not limited to this. For example, any one of the pair of output terminals 5 and 5 may be configured on the outer surface of the case 4. That is, any one of the pair of current collectors 3 and 3 is mechanically and electrically connected to the case 4 (the case main body 40 or the lid body 41) via the shaft-like member 6. Thus, either one of the output terminals 5 in which the outer surface of the case 4 (the case main body 40 or the lid body 41) is disposed outside the case 4 may be configured. In this case, the other output terminal 5 of the pair of output terminals 5 and 5 is a bolt terminal 5 similar to that of the above embodiment, or a shaft shape for fixing the current collector 3 of the corresponding polarity to the case 4. What is necessary is just to be comprised with the member 6. FIG.

  DESCRIPTION OF SYMBOLS 1 ... Power storage element (battery), 2 ... Power generation element, 3 ... Current collector (current collector for positive electrode, current collector for negative electrode) 4 ... Case, 5 ... Output terminal (output terminal for positive electrode, output terminal for negative electrode) ), 6... Shaft member (shaft member for positive electrode, shaft member for negative electrode), 7 .. Internal gasket (internal gasket for positive electrode, internal gasket for negative electrode), 8 .. External gasket (external gasket for positive electrode, external for negative electrode) Gasket), 9 ... Connecting rod (positive electrode connecting rod, negative electrode connecting rod), 20a ... positive electrode plate, 20b ... negative electrode plate, 20c ... separator, 21 ... lead portion (positive electrode lead portion, negative electrode lead portion), 22 ... flat Part, 23, 23 ... arc part, 30 ... fixing piece part, 31 ... power generation element connection part, 32 ... clip member, 40 ... case main body, 41 ... cover body, 50 ... terminal part, 51 ... detent part, 52 ... rotation member, 53 ... concave, 54 ... convex, 60 ... rivet part 61: flange part, 62: connecting rivet part (rivet part), 70: recessed part, 71 ... through hole, 80 ... recessed part, 81 ... through hole, 82 ... cylindrical part, 90 ... first hole (through hole) , 91 ... Second hole (through hole), 300 ... Base piece, 301 ... Folded piece, 302 ... Through hole, 310 ... Connection piece, 400 ... Opening, 401 ... Bottom, 402 ... Side wall, 403 ... Front and back Wall part, 410 ... through hole, 510 ... groove, P1 ... first end, P2 ... second end, P3 ... first end, P4 ... second end, P5 ... first end, P6 ... first Two ends

Claims (3)

A power generation element including a positive electrode plate and a negative electrode plate;
A pair of current collectors each electrically connected to a corresponding one of the positive electrode plate and the negative electrode plate in the power generation element;
A case containing the power generation element and the pair of current collectors;
A pair of output terminals disposed outside the case;
Each of the pair of current collectors is a pair of shaft-like members that fix a corresponding current collector of the pair of current collectors to the case in a state where each of the current collectors is inserted into the case. A pair of shaft-shaped members that electrically connect a corresponding current collector and a corresponding output terminal of the pair of output terminals;
Each of the pair of current collectors is
A fixing piece disposed along the inner surface of the case;
A power generation element connection portion extended from the fixing piece, the power generation element connection portion electrically and mechanically connected to the power generation element,
The fixing piece of at least one of the pair of current collectors is:
A base piece having a first end and a second end, wherein the first end is connected to the power generation element connection,
A folded piece portion having a first end portion and a second end portion, the first end portion comprising a folded piece portion connected to the base piece portion;
The base piece portion is disposed closer to the case than the folded piece portion,
The folded piece portion is folded to the inner side of the case at the first end portion of the folded piece portion and overlapped with the base piece portion,
At least one of the pair of shaft-shaped members is fastened to the case with the fixing piece in a state of being inserted through the case, the base piece, and the folded piece. Power storage element. The second end portion of the folded piece portion is disposed to overlap the first end portion side of the base piece portion,
The electric storage element according to claim 1, wherein at least an edge on the base piece portion side of the second end portion of the folded piece portion is chamfered. The second end of the base piece is an end opposite to the first end of the base piece,
The first end of the folded piece is connected to the second end of the base piece;
The electric storage element according to claim 2, wherein the second end portion of the folded piece portion is located on the opposite side of the first end portion of the folded piece portion.

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