JP2014216302A - Storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage element capable of lowering resistance of the storage element while strengthening bonding of a holding member, an electrode body, and a collector.SOLUTION: A holding member 7 holds a metal layer 31 of an electrode body 3 and a collecting part 41 of a collector 4 by being inserted into a hole part 35 of the electrode body 3 and being bent to an end surface 3b side of the electrode body 3. The holding member 7, the metal layer 31 of the electrode body 3, and the collecting part 41 of the collector 4 are bonded at a side surface 3a side of the electrode body 3.

Description

  The present invention relates to a power storage element.

  Conventionally, as an electrical storage element, there exist some which were described in Unexamined-Japanese-Patent No. 2003-346770 (patent document 1). The power storage device includes a container, an external terminal exposed to the outside of the container, an electrode body accommodated in the container, a current collector that electrically connects the external terminal and the electrode body, an electrode body, and a current collector. And a clamping member that clamps the electric body. Each of the both ends of the electrode body has an exposed electrode.

  As shown in FIG. 6, the current collector 104 is in contact with the electrode 131 at the end of the electrode body 103 on the side surface side of the electrode body 103. The electrode 131 includes a plurality of stacked metal layers (aluminum layer and copper layer).

  The holding member 105 is bent inward from the end surface of the electrode body 103 and sandwiches the electrode 131 and the current collector 104 at the end of the electrode body 103 so as to cover the end surface of the electrode body 103. . The electrode 131 at the end of the electrode body 103, the current collector 104, and the clamping member 105 are joined by welding on the side surface side of the electrode body 103.

JP 2003-346770 A

  By the way, when actually trying to manufacture and use the conventional power storage device, it has been found that there is the following problem.

  The clamping member 105 sandwiches the end face of the electrode body 103 and can suppress the spread between the metal layers on the end face side of the electrode body 103, but the metal layer on the inner side of the electrode body 103 remains spread. For this reason, in the part which overlaps with the electrical power collector 104 of the electrode body 103, the metal layer was spreading and the adhesiveness of the metal layer was bad. Therefore, the joining of the clamping member 105, the electrode body 103, and the current collector 104 is weakened, and the resistance of the power storage element is large.

  Accordingly, an object of the present invention is to provide a power storage element that can reduce the resistance of the power storage element while strengthening the bonding of the holding member, the electrode body, and the current collector.

In order to solve the above problems, the electricity storage device of the present invention is:
A container,
An external terminal at least a part of which is disposed outside the container;
An electrode body housed in the container;
A current collector for electrically connecting the external terminal and the electrode body;
A clamping member that clamps the electrode body and the current collector;
The electrode body has a plurality of laminated metal layers, and the metal layer is exposed at each of both ends of the electrode body,
The metal layer at the end of the electrode body has a hole penetrating in the stacking direction of the metal layer on the side surface side of the electrode body,
The current collector has a current collector that contacts the metal layer at the end of the electrode body,
The clamping member is inserted into the hole of the electrode body and bent to the end face side of the electrode body to sandwich the metal layer of the electrode body and the current collector of the current collector,
The sandwiching member, the metal layer of the electrode body, and the current collector of the current collector are joined on the side surface side of the electrode body.

  Here, the stacking direction coincides with the radial direction of the electrode body in the case of the wound electrode body, and coincides with the thickness direction of the electrode body in the case of the stacked electrode body.

  According to the electricity storage device of the present invention, the clamping member is inserted into the hole of the electrode body and is bent toward the end face side of the electrode body, so that the metal layer of the electrode body and the collector of the current collector are An electric part is clamped, The said clamping member, the said metal layer of the said electrode body, and the said current collection part of the said collector are joined by the side surface side of the said electrode body. As a result, the metal layer at the end of the electrode body is suppressed from spreading between the metal layers by the holding member, and the adhesion of the metal layer from the insertion portion to the end face side of the electrode body is improved. Therefore, the resistance of the power storage element can be lowered while strengthening the bonding of the sandwiching member, the electrode body, and the current collector.

  Further, in the electric storage device according to one embodiment, the joining portion of the clamping member, the electrode body, and the current collector is inserted into the hole of the clamping member as viewed from the side of the electrode body. It is located on the end face side of the electrode body with respect to the part, and overlaps the insertion part in both end directions connecting the both end parts of the electrode body.

  According to the electricity storage device of this embodiment, since the joint portion overlaps both ends of the insertion portion and the electrode body, the current collector can be joined at a portion having good adhesion between the metal layers.

  Moreover, in the electrical storage element of one Embodiment, the winding part wound around the end surface of the said electrode body is provided in the said current collection part.

  According to the electricity storage device of this embodiment, the current collecting part is provided with a winding part that is wound around the end face of the electrode body, so that the winding part spreads the metal layer on the end face side of the electrode body. I can hold it down. Thereby, the adhesiveness of the metal layer of an electrode body can be improved further, and the resistance of an electrical storage element can be lowered further.

  Moreover, in the electrical storage element of one Embodiment, seeing from the side surface side of the said electrode body, the width | variety of the said insertion part is larger than the width | variety of the said junction part regarding the width direction orthogonal to the said both ends direction of the said electrode body.

  According to the electricity storage device of this embodiment, since the width of the insertion portion is larger than the width of the joining portion, the width of the portion where the spread between the metal layers of the electrode body is suppressed is larger than the width of the joining portion. Can also be larger. For this reason, a current collector can be reliably joined at a portion having good adhesion between metal layers.

  According to the electricity storage device of the present invention, the clamping member is inserted into the hole of the electrode body and is bent toward the end face side of the electrode body, so that the metal layer of the electrode body and the collector of the current collector are An electric part is clamped, The said clamping member, the said metal layer of the said electrode body, and the said current collection part of the said collector are joined by the side surface side of the said electrode body. Thereby, resistance of an electrical storage element can be lowered | hung, strengthening joining of a clamping member, an electrode body, and an electrical power collector.

It is a perspective view which shows the electrical storage element of one Embodiment of this invention. It is a disassembled perspective view of the electrical storage element of the positive electrode side of an electrode body. It is a perspective view of the electrical storage element of the positive electrode side of an electrode body. It is sectional drawing of the electrical storage element by the side of the positive electrode of an electrode body. It is a side view of the electrical storage element of the positive electrode side of an electrode body. It is sectional drawing which shows the conventional electrical storage element.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 is a perspective view showing a power storage device according to an embodiment of the present invention. As shown in FIG. 1, the electric storage element includes a container 1 and an electrode body 3 accommodated in the container 1. This power storage element is, for example, a nonaqueous electrolyte secondary battery such as a lithium ion battery or a lead storage battery.

  The container 1 is made of, for example, aluminum or an aluminum alloy. The container 1 includes a container body 10 having an opening and a lid 11 that closes the opening of the container body 10.

  The electrode body 3 includes a positive electrode side metal layer 31 and a negative electrode side metal layer 32 as electrodes, and a separator 33. The positive electrode side metal layer 31 is made of an aluminum foil, and the negative electrode side metal layer 32 is made of a copper foil. The separator 33 is made of a porous resin film. The separator 33 is disposed between the positive electrode side metal layer 31 and the negative electrode side metal layer 32. The positive electrode side metal layer 31, the negative electrode side metal layer 32, and the separator 33 are laminated.

  The positive electrode side metal layer 31, the negative electrode side metal layer 32, and the separator 33 are band-shaped, and the positive electrode side metal layer 31 and the negative electrode side metal layer 32 are positioned on opposite sides of the separator 33 in the width direction. It is wound in an oval shape in a shifted state. That is, the positive electrode side metal layer 31 is exposed at one axial end portion of the electrode body 3, and the negative electrode side metal layer 32 is exposed at the other axial end portion of the electrode body 3.

  The electrode body 3 is disposed horizontally so that the oval flat side surface 3a stands upright. Current collectors 4 are disposed at both ends of the electrode body 3, respectively. That is, the current collector 4 is provided on each of the positive electrode side and the negative electrode side. The positive electrode side current collector 4 is made of aluminum, and the negative electrode side current collector 4 is made of copper. The current collector 4 is accommodated in the container 1.

  External terminals 2 are attached to the lid body 11 at positions corresponding to both ends of the electrode body 3. That is, the external terminal 2 is provided on each of the positive electrode side and the negative electrode side. The external terminal 2 on the positive electrode side is made of aluminum, and the external terminal 2 on the negative electrode side is made of copper. A part of the external terminal 2 is disposed outside the container 1.

  The positive electrode side metal layer 31 at one end of the electrode body 3 is electrically connected to the external terminal 2 on the positive electrode side via the current collector 4 on the positive electrode side. The negative electrode side metal layer 32 at the other end of the electrode body 3 is electrically connected to the negative electrode side external terminal 2 via the negative electrode side current collector 4.

  The electrode body 3 and the current collector 4 are sandwiched by a sandwiching member 7. The positive-side clamping member 7 is made of aluminum, and the negative-side clamping member 7 is made of copper.

  As shown in FIG. 2, the current collector 4 is connected to the plate-like main body portion 40, two plate-like current collector portions 41 connected to the main body portion 40, and the current collector portions 41. Two winding portions 42.

  The main body 40 is formed in a flat shape and is disposed on the upper end of the electrode body 3. The main body portion 40 is provided with a rivet hole 40a.

  The current collector 41 protrudes in the left-right direction from the edge in the left-right direction (thickness direction of the electrode body 3) of the main body 40 and is bent downward (on the electrode body 3 side). The current collector 41 extends along the side surface 3 a of the electrode body 3. The left and right current collecting portions 41, 41 are formed symmetrically with respect to the main body portion 40.

  The winding portion 42 protrudes forward from the edge of the current collecting portion 41 in the forward direction (in the direction of the end surface 3b of the electrode body 3). The two winding parts 42 are located at the middle part and the lower part of the current collector 41 in the vertical direction.

  The external terminal 2 includes a connecting rod 21, a bolt 22, and a rivet 23. The connecting rod 21 is located outside the lid body 11. The bolt 22 is screwed into the connecting rod 21, and the tip of the bolt 22 protrudes upward. An upper packing 5 is attached between the connecting rod 21 and the lid body 11. A lower packing 6 is attached between the current collector 4 and the lid 11. The upper and lower packings 5 and 6 have insulating properties and sealing properties.

  The rivet 23 is connected to the hole 40a of the main body 40 of the current collector 4, the hole 6a of the lower packing 6, the hole 11a of the lid 11, and the hole (not shown) of the upper packing 5. The hole 21a of the flange 21 is passed through in order and caulked.

  Thus, the main body portion 40 of the current collector 4 is in contact with the external terminal 2. The current collector 4 and the external terminal 2 are integrally fixed to the lid body 11.

  The electrode body 3 has a hole 35 on the side surface 3a side. The hole 35 is provided in the positive electrode side metal layer 31 at the end of the electrode body 3. The hole 35 penetrates in the stacking direction of the positive electrode side metal layer 31 and the negative electrode side metal layer 32. That is, the hole 35 penetrates from the outer peripheral surface to the inner peripheral surface of the electrode body 3 in the radial direction. The hole 35 has a slit shape, and is viewed in the width direction (of the wound electrode body 3 of the wound electrode body 3) perpendicular to both end directions of the electrode body 3 (axial direction of the wound electrode body 3) when viewed from the side surface 3 a side of the electrode body 3. (Circumferential direction). In addition, when providing the hole part 35 in the positive electrode side metal layer 31 of the electrode body 3, let the direction which the burr | flash comes out of the positive electrode side metal layer 31 be the end surface 3b direction (axial direction outer side) of the electrode body 3.

  The clamping member 7 has a plate-like main body portion 70 and a plate-like projecting piece portion 71 connected to the main body portion 70. The main body portion 70 is located on the outer peripheral surface side of the electrode body 3, and the projecting piece portion 71 is inserted through the hole portion 35 of the electrode body 3.

  As shown in FIGS. 3 and 4, the current collector 41 of the current collector 4 is in contact with the positive electrode side metal layer 31 of the electrode body 3. The winding portion 42 of the current collector 4 is bent from the end surface 3 b side of the electrode body 3 to the inner side, and is wound around the end surface 3 b of the electrode body 3.

  The clamping member 7 is inserted into the hole 35 of the electrode body 3 and is bent toward the end surface 3 b side of the electrode body 3, so that the positive electrode side metal layer 31 of the electrode body 3 and the current collector 41 of the current collector 4 are sandwiched. To do. The main body 70 of the clamping member 7 contacts the current collector 41 of the current collector 4. The projecting piece portion 71 of the holding member 7 has an insertion portion 711 and a winding portion 712. The insertion part 711 is a part inserted into the hole part 35. The winding portion 712 is bent from the inner side of the electrode body 3 to the end face 3 b side and wound around the end face 3 b of the electrode body 3.

  The clamping member 7, the positive metal layer 31 at the end of the electrode body 3, and the current collector 41 of the current collector 4 are joined by welding on the side surface 3 a side of the electrode body. That is, the clamping member 7, the current collector 4, and the electrode body 3 are integrally joined by ultrasonic welding from both sides of the clamping member 7.

  As shown in FIG. 5, the joining portion 8 of the sandwiching member 7, the electrode body 3, and the current collector 4 is more electrode body 3 than the insertion portion 711 of the sandwiching member 7 when viewed from the side surface 3 a side of the electrode body. Is located on the end face 3b side. The joint portion 8 overlaps with the insertion portion 711 in both end directions (left and right direction in FIG. 5) of the electrode body 3 when viewed from the side surface 3a side of the electrode body 3. When viewed from the side surface 3 a side of the electrode body 3, the width W <b> 1 of the insertion portion 711 is larger than the width W <b> 2 of the joint portion 8 in the width direction (vertical direction in FIG. 5) perpendicular to both end directions of the electrode body 3. That is, all of the joint portions 8 overlap the insertion portion 711 in the both end directions of the electrode body 3.

  A gap is provided between the inner surface of the hole portion 35 of the electrode body 3 and the insertion portion 711 of the clamping member 7. That is, this gap is at least between the inner surface of the hole 35 on the side opposite to the end surface 3 b and the insertion portion 711. Therefore, since this gap is provided, contamination (foreign matter or copper powder generated by tearing the foil) is generated from the foil at the contact portion of the electrode body 3 that is in contact with the insertion portion 711 due to vibration during ultrasonic welding. Can prevent it from occurring

  2 to 5, the current collector 4 on the positive electrode side of the electrode body 3, the external terminal 2, and the sandwiching member 7 have been described. However, the current collector 4 on the negative electrode side of the electrode body 3, the external terminal 2 and the sandwiching member 7 are described. The member 7 has the same configuration.

  Next, a method for assembling the electricity storage device having the above configuration will be described.

  As shown in FIG. 2, the current collector 41 of the current collector 4 is brought into contact with the positive electrode side metal layer 31 at the end of the electrode body 3. The protruding piece 71 of the holding member 7 is inserted through the hole 35 of the electrode body 3.

  Then, as shown in FIG. 3, the protruding piece 71 of the holding member 7 is bent from the inner side of the electrode body 3 to the end face 3 b side, and the positive electrode side metal layer 31 of the electrode body 3 and the current collector 4 are held by the holding member 7. The current collector 41 is sandwiched. Further, the winding portion 42 of the current collector 4 is bent from the end surface 3 b side of the electrode body 3 to the inner side and wound around the end surface 3 b of the electrode body 3.

  After that, as shown in FIG. 5, the clamping member 7, the positive electrode side metal layer 31 at the end of the electrode body 3, and the current collector 41 of the current collector 4 are welded on the side surface 3 a side of the electrode body 3. To join. At this time, the joining portion 8 is located closer to the end surface 3b side of the electrode body 3 than the insertion portion 711 of the clamping member 7 when viewed from the side surface 3a side of the electrode body, and the insertion portion in both end directions of the electrode body 3 711 to overlap. In addition, the negative electrode side of the electrode body 3 is assembled in the same manner as the positive electrode side of the electrode body 3.

  According to the electricity storage device having the above configuration, the holding member 7 is inserted into the hole 35 of the electrode body 3 and bent toward the end surface 3b side of the electrode body 3, and the metal layer (positive electrode) of the electrode body 3 is bent. Side metal layer 31 and negative electrode side metal layer 32) and current collector 41 of current collector 4 are sandwiched. The clamping member 7, the metal layer of the electrode body 3, and the current collector 41 of the current collector 4 are joined on the side surface 3 a side of the electrode body 3. As a result, the metal layer at the end of the electrode body 3 is suppressed from spreading between the metal layers by the clamping member 7, and the adhesion of the metal layer from the insertion portion 711 to the end surface 3 b side of the electrode body 3 is improved. improves. Therefore, the resistance of the power storage element can be lowered while strengthening the bonding of the sandwiching member 7, the electrode body 3, and the current collector 4.

  Moreover, since the said junction part 8 overlaps in the both ends direction of the insertion part 711 and the electrode body 3, the electrical power collector 4 can be joined in this part with the sufficient adhesiveness between metal layers.

  In the welding operation, the current collector 4 and the electrode body 3 are sandwiched by the sandwiching member 7, and the spread between the metal layers of the electrode body 3 is pressed by the sandwiching member 7, and then the sandwiching member 7, the electrode body 3 and the current collector are collected. The body 4 can be welded. Thereby, welding work can be performed stably.

  Further, since welding is performed on the side surface 3 a of the electrode body 3, welding can be performed near the insertion portion 711 of the holding member 7 as compared with the case where welding is performed on the end surface 3 b of the electrode body 3. That is, since the welding is performed at the portion where the spread between the metal layers of the electrode body 3 is most suppressed, the resistance of the power storage element can be effectively reduced.

  Moreover, since the said clamping member 7 is penetrated by the said hole part 35 of the said electrode body 3, even if an electrical storage element receives a vibration, the shift | offset | difference of the metal layer of the electrode body 3 can be prevented, for example.

  In addition, when the current collector 4 and the negative electrode side metal layer 32 of the electrode body 3 are ultrasonically welded, the copper powder is scattered, but the insertion portion 711 of the sandwiching member 7 is more than the joint portion 8. Since it is located inside the electrode body 3, the insertion portion 711 can prevent the copper powder from entering the electrode body 3. Accordingly, it is possible to prevent a reduction in the capacity of the electricity storage element due to the mixture of copper powder into the electrode body 3.

  Moreover, since the winding part 42 wound around the end surface 3b of the electrode body 3 is provided in the current collector 41, the winding part 42 suppresses the spread between the metal layers on the end surface 3b side of the electrode body 3. be able to. Thereby, the adhesiveness of the metal layer of the electrode body 3 can be further improved, and the resistance of the electricity storage element can be further reduced.

  Further, since the width W1 of the insertion portion 711 is larger than the width W2 of the joint portion 8, the width of the portion of the electrode body 3 where the spread between the metal layers is suppressed is larger than the width of the joint portion 8. it can. For this reason, the current collector 4 can be reliably bonded at a portion having good adhesion between the metal layers. Moreover, it can prevent more reliably that the copper powder scattered at the time of welding enters the inside of the electrode body 3.

  In addition, this invention is not limited to the above-mentioned embodiment. In the above embodiment, the number of current collectors of the current collector is two, but may be one or three or more.

  In the above embodiment, the sandwiching member, the electrode body, and the current collector are joined by ultrasonic welding, but may be joined by welding such as laser welding, or joined by resistance welding, solid phase joining, or the like. You may do it. In the said embodiment, although the winding part was provided in the current collection part, you may abbreviate | omit a winding part. In the above embodiment, a sheet metal current collector is used, but a current collector made of a lead wire may be used.

  In the above-described embodiment, the entire joining portion is overlapped with the insertion portion in both end directions of the electrode body. However, a part of the joining portion may be overlapped with the insertion portion. In the said embodiment, although the width | variety of the insertion part was made larger than the width | variety of a junction part, it is good also as making the width | variety of an insertion part smaller than the width | variety of a junction part, or equivalent.

  In addition, although aluminum and aluminum alloy were illustrated as an example of the material of a container, the effect of this invention is not restrict | limited also by other materials, for example, stainless steel, iron, nickel, nickel steel, etc. Although aluminum and copper are exemplified as the material of the terminal and the current collector, the effect of the present invention is not limited even if other materials are used. Moreover, even if nickel plating etc. are implemented, the effect of this invention is not restrict | limited.

  In the above embodiment, an elliptical wound electrode body has been described. However, in the case of a laminated electrode body, the current collector is similarly electrically connected to the electrode exposed at the end of the electrode body. Can be connected to. In this case, the hole of the electrode body penetrates in the thickness direction of the electrode body. In the above embodiment, the non-aqueous electrolyte secondary battery has been described as the power storage element, but the present invention is also applicable to a capacitor or the like.

DESCRIPTION OF SYMBOLS 1 Container 10 Container main body 11 Cover body 2 External terminal 3 Electrode body 3a Side surface 3b End surface 31 Positive electrode side metal layer 32 Negative electrode side metal layer 35 Hole part 4 Current collector 40 Main body part 41 Current collection part 42 Winding part 7 Clamping member 70 Main body Part 71 Projection part 711 Insertion part 712 Winding part 8 Joining part W1 Insertion part width W2 Joining part width

Claims (4)

A container,
An external terminal at least a part of which is disposed outside the container;
An electrode body housed in the container;
A current collector for electrically connecting the external terminal and the electrode body;
A clamping member that clamps the electrode body and the current collector;
The electrode body has a plurality of laminated metal layers, and the metal layer is exposed at each of both ends of the electrode body,
The metal layer at the end of the electrode body has a hole penetrating in the stacking direction of the metal layer on the side surface side of the electrode body,
The current collector has a current collector that contacts the metal layer at the end of the electrode body,
The clamping member is inserted into the hole of the electrode body and bent to the end face side of the electrode body to sandwich the metal layer of the electrode body and the current collector of the current collector,
The power storage element, wherein the holding member, the metal layer of the electrode body, and the current collector of the current collector are joined on a side surface side of the electrode body. The electricity storage device according to claim 1,
The joining portion of the clamping member, the electrode body, and the current collector is closer to the end face side of the electrode body than the insertion part inserted into the hole of the clamping member when viewed from the side surface side of the electrode body. A power storage element that is positioned and overlaps the insertion portion in both end directions connecting the both end portions of the electrode body. The electricity storage device according to claim 1 or 2,
The electricity storage element, wherein the current collector is provided with a winding portion wound around an end face of the electrode body. In the electrical storage element of Claim 2 or 3,
An electrical storage element, wherein a width of the insertion portion is larger than a width of the joint portion in a width direction orthogonal to the both end directions of the electrode body as viewed from a side surface of the electrode body.

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