JP5761079B2 - battery - Google Patents

Description

  The present invention relates to a battery, and more particularly to a battery including a current collector joined to a power generation element.

  Conventionally, a battery including a current collector joined to a power generation element is known (see, for example, Patent Document 1).

  Patent Document 1 discloses a battery including a terminal, a power generation element, and a current collector connection (current collector) joined to the power generation element. The current collector connection body includes a terminal connection portion to which a terminal is connected, a plurality of rod-like connection portions joined to the power generation element, and a branch portion that connects the terminal connection portion and the plurality of connection portions. Yes. The plurality of rod-like connecting portions are formed so as to branch from the branch portion into a comb shape and extend to one side.

JP 2003-346770 A

  However, in the battery disclosed in Patent Document 1, since the plurality of connection portions are formed so as to extend only from the terminal to one side, the current path between the terminal connection portion and the plurality of connection portions is the terminal. Only one part of the connection part. For this reason, current concentrates at a branch portion between the terminal connection portion and the plurality of connection portions, and the current collector connection sometimes generates heat.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to prevent the current collector from generating heat due to current concentration.

  The battery of the present invention includes a terminal, a power generation element, a current collector including a first current collecting portion formed on one side with respect to the terminal, and a second current collecting portion formed on the other side with respect to the terminal. The first current collecting portion and the second current collecting portion each have a plurality of branched rod-shaped portions, and the plurality of rod-shaped portions and the power generation element are joined to each other.

  In the battery according to the present invention, as described above, the first current collecting portion formed on one side of the terminal and the second current collecting portion formed on the other side of the terminal are provided with the current collector. Since the current is distributed to the path via the current collecting part and the path via the second current collecting part, the current collector can be prevented from generating heat due to the current concentration. Further, it is possible to efficiently collect current by using both the first current collecting portion and the second current collecting portion respectively formed on both sides of the terminal.

  In the above battery, preferably, a stack of current collector foils is formed at the end of the power generation element, and the plurality of rod-shaped portions are arranged on the outer surface of the current collector foil stack or on the outermost layer. The plurality of rod-shaped portions and the current collector foil are joined. If comprised in this way, since the area | region which a rod-shaped part and current collection foil contact can be enlarged, a collector and the pole plate of an electric power generation element can be joined more firmly. Moreover, when arrange | positioning a rod-shaped part in the outer surface of the outermost layer, compared with the case where a rod-shaped part is inserted between the layers of current collection foil, a rod-shaped part can be easily arrange | positioned in a joining location.

  In this case, preferably, the current collecting foil in which the bar-shaped part of the first current collecting part is disposed and the outer surface of the laminated current collecting foil or the outermost layer of the current collecting foil and the bar-shaped part of the second current collecting part are arranged. The location of the foil lamination layer or the outermost surface of the outermost layer differs in the lamination direction of the current collector foil. By making the joining location of the rod-shaped portion of the first current collecting portion and the current collector foil different from the joining location of the rod-shaped portion of the second current collecting portion and the current collector foil in the stacking direction, that is, the rod-shaped portion And the current collecting foil are dispersed and arranged in the stacking direction of the current collecting foil, so that the current path with the power generating element can be collected efficiently without being localized. Further, when the current collector foil layers are gathered and joined to the rod-shaped portion, one rod-shaped portion is obtained by dispersing and arranging the joint portions of the rod-shaped portion and the current collector foil in the stacking direction of the current collector foil. Even if the number of current collecting foils collected is reduced, the current can be collected uniformly. By reducing the number of current collecting foils collected, the bonding strength between the rod-shaped portion and the current collecting foil can be increased.

  According to the present invention, the current collector can be prevented from generating heat due to current concentration.

It is the perspective view which showed the completion state of the battery by one Embodiment of this invention. 1 is an exploded perspective view showing an overall configuration of a battery according to an embodiment of the present invention. 1 is an exploded perspective view showing a positive electrode current collector, a negative electrode current collector, and a power generation element according to an embodiment of the present invention. It is the top view which showed the positive electrode electrical power collector by one Embodiment of this invention. It is the top view which showed the positional relationship of the positive electrode electrical power collector by one Embodiment of this invention, and an electric power generation element.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

  First, a configuration of a battery 100 according to an embodiment of the present invention will be described with reference to FIGS.

  The battery 100 according to an embodiment of the present invention is a lithium ion battery. As shown in FIG. 2, the battery 100 includes a rectangular cylindrical battery case 1 and a wound power generation element 2 housed inside the battery case 1. The battery case 1 is made of a stainless steel plate, and openings 11 and 12 are formed at both ends of the battery case 1 in the Y direction. The opening 11 is provided with a lid 3 and a positive external terminal 4, and the opening 12 is provided with a lid 3 and a negative external terminal 5. The battery 100 further includes a positive electrode current collector 6 that electrically connects the positive electrode external terminal 4 and the power generation element 2, and a negative electrode current collector 7 that electrically connects the negative electrode external terminal 5 and the power generation element 2. ing. The positive external terminal 4 and the negative external terminal 5 are examples of the “terminal” in the present invention, and the positive current collector 6 and the negative current collector 7 are examples of the “current collector” in the present invention.

  As shown in FIG. 3, the power generation element 2 is formed by winding a belt-like positive electrode plate 2a and a belt-like negative electrode plate 2b into a long cylindrical shape via a separator 2c. The power generating element 2 is wound so that the current collector foil of the positive electrode plate 2a protrudes from the end portion on one side (Y1 side) and the current collector foil of the negative electrode plate 2b protrudes from the end portion on the other side (Y2 side). ing. That is, the current collector foil of the negative electrode plate 2b not coated with the negative electrode mixture is formed by stacking the current collector foils of the positive electrode plate 2a not coated with the positive electrode mixture on one end (Y1 side) of the power generating element 2. Is formed on the other end (Y2 side) of the power generation element 2. A stack of current collector foils of the positive electrode plate 2a and a stack of current collector foils of the negative electrode plate 2b are disposed on the opening 11 side and the opening 12 side of the battery case 1, respectively. The current collector foil of the positive electrode plate 2a and the current collector foil of the negative electrode plate 2b are examples of the “current collector foil” in the present invention.

  As shown in FIG. 2, the lid 3 is made of the same stainless steel plate as that of the battery case 1 and is divided into three parts before assembly. Specifically, the lid 3 includes a central blocking portion 31 that covers the central portion of the opening 11 (12) of the battery case 1 and two end blocking portions 32 that cover both ends of the opening 11 (12). It is divided into and. The central closing portion 31 and the two end closing portions 32 are coupled to each other by welding when the battery 100 is assembled. A positive external terminal 4 (negative external terminal 5) is attached to the central blocking portion 31 on the positive electrode side (negative electrode side). The positive external terminal 4 and the negative external terminal 5 are made of aluminum and copper as main materials, respectively.

  The positive electrode current collector 6 is disposed on the opening 11 side of the battery case 1, and the negative electrode current collector 7 is disposed on the opening 12 side of the battery case 1. As shown in FIG. 3, the positive electrode current collector 6 is made of an aluminum plate, and includes a terminal attachment portion 61 to which the positive electrode external terminal 4 is connected, and a first current collector formed on one side (Z1 side) of the terminal attachment portion 61. It has the electricity part 62 and the 2nd current collection part 63 formed in the other side (Z2 side) of the terminal attachment part 61. FIG. The terminal mounting portion 61, the first current collecting portion 62, and the second current collecting portion 63 are integrally formed by bending an aluminum plate. The negative electrode current collector 7 is made of a copper plate, has the same shape as the positive electrode current collector 6, and includes a terminal mounting portion 71, a first current collector portion 72, and a second current collector portion 73. Yes. Hereinafter, the configuration on the positive electrode side will be described in detail, and the detailed description on the negative electrode side will be omitted.

  The terminal mounting portion 61 of the positive electrode current collector 6 is provided so as to protrude from the central portion of the positive electrode current collector 6 and has an opening 61 a formed in the central portion. In order to ensure insulation and airtightness between the terminal mounting portion 61 and the central closing portion 31 and between the positive external terminal 4 and the central closing portion 31, resin packing is provided between them. . The positive electrode external terminal 4 and the central blocking portion 31 are connected to the positive electrode current collector 6 by caulking the protrusion of the positive electrode external terminal 4 inserted into the opening 61a with a resin packing provided between them. It is attached to the terminal attachment part 61.

  Here, in the present embodiment, as shown in FIGS. 3 and 4, the first current collecting portion 62 formed on one side (Z1 side) of the terminal mounting portion 61 has four rod-shaped portions 62 a, 62 b, 62 c. And 62d, and a branch portion 62e that connects the terminal mounting portion 61 and the rod-shaped portions 62a to 62d. The second current collecting portion 63 formed on the other side (Z2 side) of the terminal attachment portion 61 includes four rod-like portions 63a, 63b, 63c and 63d, a terminal attachment portion 61 and rod-like portions 63a to 63d. And a branch part 63e to be connected. Both the rod-shaped portions 62a to 62d and the rod-shaped portions 63a to 63d are formed so as to extend along the longitudinal direction (Z direction) of the power generation element 2.

  As shown in FIG. 4, the rod-shaped portions 62 a to 62 d and the rod-shaped portions 63 a to 63 d are formed at a distance D from each other in the stacking direction (X direction) of the current collector foil of the positive electrode plate 2 a. Further, the positions of the rod-shaped portions 62a to 62d in the stacking direction (X direction) and the positions of the rod-shaped portions 63a to 63d in the stacking direction (X direction) are not overlapped, and as shown in FIG. The first current collecting portion 62 and the second current collecting portion 63 are formed so as to be asymmetric (non-mirror image symmetric) with respect to the center line A of the terminal mounting portion 61.

  The rod-shaped portions 62a to 62d of the first current collecting portion 62 are provided with insertion portions 162a, 162b, 162c, and 162d that are joined to the current collecting foil of the positive electrode plate 2a. These insertion portions 162a to 162d are formed by bending part of the flat plate portions of the rod-shaped portions 62a to 62d to the inside (Y2 side) of the battery case 1, and are joined to the current collector foil of the positive electrode plate 2a. It has a flat part. Note that the insertion portions 163a, 163b, 163c, and 163d are also formed in the rod-like portions 63a to 63d of the second current collecting portion 63.

  In the present embodiment, the insertion portions 162 a to 162 d and the insertion portions 163 a to 163 d are joined to the current collector foil of the positive electrode plate 2 a disposed at the end of the power generation element 2. Each insertion portion is inserted between the layers of the current collector foil layers, or is disposed on the outer surface of the outermost layer of the current collector foil and joined to the current collector foil of the positive electrode plate 2a. Specifically, the insertion part 162a and the insertion part 163d are disposed on the outermost surfaces 102a and 102b of the outermost layer of the current collector foil, and the insertion parts 162b to 162d and the insertion parts 163a to 163c are respectively current collectors. It is inserted in the interlayers 102c to 102h of the laminated foil.

  Each insertion portion and the current collector foil of the positive electrode plate 2a are joined to each other in a state of being sandwiched between the sandwiching plates 8 (see FIG. 2). Specifically, as shown in FIG. 5, a plurality of current collector foils are gathered together, and the layers of the current collector foil formed by gathering and the insertion portion are joined in a state of being sandwiched between sandwiching plates 8. Yes. Thereby, the positive electrode plate 2a of the power generation element 2 and the positive electrode current collector 6 are electrically connected.

  The insertion parts 162a, 162b, 163a and 163b are joined to the current collecting foil layer on the X2 side, and the insertion parts 162c, 162d, 163c and 163d are joined to the current collecting foil layer on the X1 side. At this time, most of the current collector foils are gathered only in one of the insertion portions. As a result, a layer with a small number of current collector foils can be distributed to each insertion portion, so that the thickness of the current collector foil layer can be reduced and the bonding strength between the current collector foil and the insertion portion is increased. be able to.

  Next, with reference to FIG. 1, FIG. 2, and FIG. 5, the assembly procedure of the battery 100 of this embodiment is demonstrated.

  First, as shown in FIG. 2, the positive external terminal 4 is attached to the terminal attachment portion 61 of the positive electrode current collector 6 via the central closing portion 31. And as shown in FIG. 5, while arrange | positioning the insertion part 162a of the 1st current collection part 62 of the positive electrode collector 6 on the outer surface 102a of the lamination | stacking of current collection foil, the insertion parts 162b-162d are respectively current collection. Inserted between the layers 102c to 102e of the laminated foil. In addition, the insertion portion 163d of the second current collecting portion 63 is arranged on the outer surface 102b of the current collector foil stack, and the insert portions 163a to 163c are inserted into the current collector foil stack layers 102f to 102h, respectively.

  Then, each insertion part and the collected current collector foil layer are joined by ultrasonic welding in a state of being sandwiched between the sandwiching plates 8 (see FIG. 2). Under the present circumstances, it joins in the state which the planar part and current collection foil of each insertion part contacted. Thereby, the positive electrode current collector 6 and the positive electrode plate 2a of the power generation element 2 are electrically connected. Further, the negative electrode current collector 7 and the negative electrode plate 2 b of the power generation element 2 are connected in the same manner as the connection method between the positive electrode current collector 6 and the positive electrode plate 2 a of the power generation element 2.

  Then, as shown in FIG. 1, the two end closing portions 32 are fitted so as to sandwich the central closing portion 31, and the central closing portion 31 and the two end closing portions 32 are integrated with each other by welding. 3 is formed. Moreover, the peripheral part of the integrated cover part 3 and the peripheral part of the opening part 11 (12) of the battery case 1 are joined by welding. By injecting the electrolytic solution into the battery case from an inlet (not shown), the assembly of the battery 100 of this embodiment is completed.

  In the present embodiment, as described above, the positive electrode current collector 6 includes the first current collecting portion 62 formed on the Z1 side of the positive electrode external terminal 4 and the second current collector formed on the Z2 side of the positive electrode external terminal 4. Since the current portion 63 is included, the current is distributed to the route via the first current collector portion 62 and the route via the second current collector portion 63, so that the positive electrode current collector 6 is caused by the current concentration. Heat generation can be suppressed. Further, it is possible to efficiently collect current by using both the first current collecting portion 62 and the second current collecting portion 63 formed on both sides of the positive electrode external terminal 4. As a result, even in the case of medium-sized and large-sized batteries having a large charge / discharge current, heat generation of the positive electrode current collector 6 can be suppressed while sufficiently collecting current.

  Further, in the present embodiment, as described above, the insertion portions 162a to 162d that are a part of the rod-shaped portions 62a to 62d and the insertion portions 163a to 163d that are a part of the rod-shaped portions 63a to 63d are connected to the current collector foil. It arrange | positions in the outer surfaces 102a and 102b of the outermost layer of a lamination | stacking, or it arrange | positions by inserting and arrange | positioning in the interlayer 102c-102h of the lamination | stacking of a current collection foil, and contact | connects the current collection foil of each positive electrode plate 2a The area can be widened. As a result, the positive electrode current collector 6 and the positive electrode plate 2a of the power generation element 2 can be bonded more firmly. Further, by placing the insertion portions 162a and 163d on the outer surfaces 102a and 102b of the outermost layer, the insertion portions 162a and 163d can be easily placed at the joints.

  Moreover, in this embodiment, as above-mentioned, each of insertion part 162a-162d and each of insertion part 163a-163d are arrange | positioned on the outer surface of a different layer and outermost layer in the lamination direction (X direction) of current collection foil. In other words, each of the insertion portions 162a to 162d and the insertion portions 163a to 163d is distributed and arranged in the stacking direction of the current collector foil, so that the current path with the power generating element 2 is not locally localized. Can collect current. Further, by arranging the insertion portions 162a to 162d and the insertion portions 163a to 163d in a distributed manner in the stacking direction of the current collector foils, the number of current collectors gathered in one insertion portion can be reduced evenly. Since current can be collected, the thickness of the current collector foil layer can be reduced by reducing the number of current collector foils gathered, and the bonding strength between the insertion portion and the current collector foil can be increased.

  Further, in the present embodiment, the positions in the stacking direction (X direction) of the rod-shaped portions 62a to 62d of the first current collecting portion 62 and the positions in the stacking direction of the rod-shaped portions 63a to 63d of the second current collecting portion 63 do not overlap. In other words, the first current collecting portion 62 and the second current collecting portion 63 are asymmetric (non-mirror image symmetric) with respect to the center line A of the terminal mounting portion 61. Each of 162d and insertion part 163a-163d can be easily arrange | positioned on the outer surface of a different layer or outermost layer in the lamination direction of current collection foil.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  In the said embodiment, although the insertion part of the 1st current collection part and the insertion part of the 2nd current collection part were each shown in the outer surface of a different layer or outermost layer in the lamination direction of current collection foil, this embodiment was shown. The invention is not limited to this. In this invention, you may arrange | position the insertion part of a 1st current collection part, and the insertion part of a 2nd current collection part in the outer surface of the same interlayer or the outermost layer. Further, a part of the first current collecting part and a part of the second current collecting part are arranged on the outer surface of the same layer or outermost layer, and the other inserting part is placed on a different interlayer or outermost layer. You may arrange | position on the outer surface of.

  In the said embodiment, although the example which has arrange | positioned the insertion part of the 1st current collection part and the insertion part of the 2nd current collection part to both the lamination layers of the current collection foil and the outer surface of the outermost layer was shown, The invention is not limited to this. In the present invention, the insertion portion may be disposed only between the layers, or may be disposed only on the outer surface of the outermost layer.

  In the said embodiment, although the example comprised so that many current collection foils were gathered together only in any one of the insertion parts was shown, this invention is not limited to this. In the present invention, one current collector foil may be gathered and joined to a plurality of different insertion portions.

  In the said embodiment, although the example which provided the four rod-shaped parts in the one side and the other side of the positive electrode collector was shown, this invention is not limited to this. In the present invention, a plurality of rod-like portions other than four may be provided on the current collector on one side and the other side of the positive electrode current collector. Moreover, the number of the bar-shaped parts on one side and the number of the bar-shaped parts on the other side may be different.

  In the said embodiment, although the winding type electric power generation element formed by winding a positive electrode, a negative electrode, and a separator was shown as an example of the electric power generation element of this invention, this invention is not limited to this. In the present invention, a laminated power generation element formed by laminating a positive electrode, a negative electrode, and a separator may be used.

  In the said embodiment, although the example which made the space | interval of rod-shaped parts the same was shown, this invention is not limited to this. In the present invention, the interval between the rod-shaped portions may be varied according to the positional relationship between the arranged layers and the outer surfaces of the outermost layers. In addition, since it becomes possible to increase the amount of insertion between layers (insertion depth) by increasing the interval between the rod-shaped portions, the junction area between the current collector foil and the insertion portion is increased. It is possible to increase the bonding strength.

  In the said embodiment, although the example which applies the electrical power collector of this invention to both a positive electrode electrical power collector and a negative electrode electrical power collector was shown, this invention is not limited to this. The current collector of the present invention may be applied to only one of the positive electrode current collector and the negative electrode current collector.

  In the above embodiment, an example in which the terminal mounting portion, the first current collecting portion, and the second current collecting portion are integrally formed by bending a metal plate (aluminum plate and copper plate) has been shown. Not limited to. In the present invention, the terminal mounting portion, the first current collecting portion, and the second current collecting portion may be formed by separate members and integrated by connecting them. Alternatively, the plurality of rod-shaped portions of the first current collecting member and the plurality of rod-shaped portions of the second current collecting member may be formed by separate members and integrated by connecting them to the branch portion.

  In the said embodiment, although the example which applies this invention to a lithium ion battery was shown, you may apply this invention to batteries other than lithium ion batteries, such as a nickel hydride battery, for example.

2 Power generation element 4 Positive external terminal (terminal)
5 Negative external terminal (terminal)
6 Positive current collector (current collector)
7 Negative electrode current collector (current collector)
62, 72 First current collecting part 62a, 62b, 62c, 62d, 63a, 63b, 63c, 63d Rod-like part 63, 73 Second current collecting part 100 Battery 102a, 102b Outer surface of outermost layer 102c, 102d, 102e, 102f, 102g, 102h between layers

Claims (2)

A terminal, a power generation element, and a current collector including a first current collecting portion formed on one side with respect to the terminal and a second current collecting portion formed on the other side with respect to the terminal,
Each of the first current collecting portion and the second current collecting portion has a plurality of branched rod-shaped portions, and the plurality of rod-shaped portions are longitudinal lengths of end surfaces of the power generating element facing the current collector. The battery is formed so as to extend along a direction, and the plurality of rod-shaped portions and the power generation element are joined along the longitudinal direction . At the end of the power generation element, a stack of current collector foils is formed,
The plurality of rod-shaped portions are disposed on the outer surface of the layer or the outermost layer of the current collector foil, and the plurality of rod-shaped portions and the current collector foil are joined together ,
The current collecting foil is disposed on the outer surface of the layer or outermost layer of the current collecting foil where the rod-shaped portion of the first current collecting portion is disposed, and the current collecting portion on which the rod-shaped portion of the second current collecting portion is disposed. 2. The battery according to claim 1 , wherein an interlayer between the laminated foils or a portion on the outer surface of the outermost layer is different in the lamination direction of the current collector foil .

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