JP2017016768A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack that can make it difficult to take out, from a case, a single battery of a battery laminate which is once accommodated in the case with neither a member different from the case nor adhesive agent.SOLUTION: A battery pack includes a battery laminate configured by laminating a plurality of single batteries 20 each containing an exterior body having a seal portion 25b, and a lower case 73 that has two opposed side walls 73c and a bottom plate, and houses the battery laminate by inserting the same through an opening portion defined by the side walls 73c along the lamination direction. The seal portion of the single battery constituting the battery laminate is bent so that a bending angle with respect to the main body portion is elastically changeable at an end portion of the exterior body which is not provided with the pair of electrode tabs. On the inner surface of the side wall 73c of the case is formed a protruding portion 79 to which the tip portion 29 of the bent seal portion 25b of the single battery 20 is fitted.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an assembled battery.

  Conventionally, various methods have been proposed as a method for holding and fixing the unit cells constituting the assembled battery. For example, Patent Document 1 discloses a battery including a battery holder in which holding walls are formed on three sides of a rectangular bottom plate that is sandwiched between each unit cell to place the unit cell at a fixed position inside. A pack (assembled battery) is disclosed.

JP 2014-22238 A

  A battery pack as described in Patent Document 1 is sometimes housed and installed in a case. In that case, each unit cell once accommodated in the case is preferably configured to be difficult to remove from the case for the purpose of preventing mischief. In addition, it is desirable that such a configuration be realized without using a member, an adhesive, or the like other than the case.

  An assembled battery which is one embodiment of the present disclosure is an exterior body made of a sheet material, and is a flat body body that houses a power generation element, and a seal formed by joining edges of the sheet material A battery stack comprising a plurality of unit cells including an exterior body having a portion at the end of the main body and a pair of electrode tabs extending from the end of the exterior body, and at least two opposing side walls And a bottom plate or a top plate, and a case for inserting and storing the battery stack along the stacking direction from the opening defined by the side wall, and the seal portion of the unit cell constituting the battery stack is The bending angle with respect to the main body at the end of the exterior body where the pair of electrode tabs are not provided is bent so that it can be elastically changed, and the inner end of the side wall of the case has a tip of the bent sealing portion of the unit cell A protrusion that engages That.

  According to the assembled battery which is one aspect of the present disclosure, it is possible to make it difficult to take out the battery cell unit cell once accommodated in the case from the case without using a member or an adhesive different from the case.

It is a disassembled perspective view which shows the assembled battery which is an example of embodiment in the state seen from the front. It is a perspective view showing the assembled battery which is an example of an embodiment in the state seen from back. It is a perspective view of the cell which is an example of an embodiment. It is a perspective view which shows the battery laminated body which is an example of embodiment in the state seen from the front. It is a perspective view which shows the state which looked at the parallel block which is an example of embodiment from the front. It is a perspective view which shows the battery laminated body which is an example of embodiment in the state seen from back. FIG. 3 is a partial cross-sectional view taken along line AA in FIG. 2. It is a disassembled perspective view which shows the assembled battery which is another example of embodiment in the state seen from the front. It is a partial cross section figure corresponding to FIG. 7 in the assembled battery which is another example of embodiment.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to the application, purpose, specification, and the like. In addition, when a plurality of embodiments and modifications are included in the following, it is assumed from the beginning that these characteristic portions are used in appropriate combinations. Furthermore, in the present specification, the description of “substantially” is intended to include the case where substantially the same is recognized as substantially the same as the case where substantially the same is described as an example.

  In the present specification, the length direction in the assembled battery and its constituent elements means the direction in which the electrode tab is drawn out from the exterior body of the unit cell, and in the following embodiment, the pair of electrode tabs are in the length direction of the exterior body. The example pulled out from the one end part of will be described. In the following, the direction along the stacking direction in which the cells are stacked may be referred to as the vertical direction, and the direction orthogonal to the length direction and the vertical direction is referred to as the width direction. Furthermore, in the following, the surface along the vertical direction located at one end in the length direction of the battery stack from which the electrode tab extends is referred to as “front surface”, the surface opposite to the front surface is referred to as “rear surface”, and the front surface and rear surface A surface substantially orthogonal to the “side surface” is defined as a “side surface”. These front, rear and side surfaces are the same for the case.

  FIG. 1 is an exploded perspective view showing the assembled battery 10 as viewed from the front. FIG. 2 is a perspective view showing the assembled battery 10 as viewed from the rear. FIG. 3 is a perspective view of the unit cell 20 constituting the assembled battery 10.

  As shown in FIG. 1, the assembled battery 10 includes a battery stack 11 configured by stacking a plurality of unit cells 20 in the same direction. The battery stack 11 has, for example, a substantially rectangular parallelepiped shape, and has a vertical dimension <width dimension <length dimension. As shown in FIG. 3, the unit cell 20 constituting the battery stack 11 includes a package body 21 composed of two laminate films 22 and 23 and a pair extending from one end in the length direction of the package body 21. A laminated battery having a positive electrode tab 26 and a negative electrode tab 27.

  The battery exterior body is not limited to one constituted by two laminated films 22 and 23, and may be constituted by, for example, one laminated film or may be constituted by a metal sheet material. . Moreover, about a pair of electrode tab, the positive electrode tab may be arrange | positioned at the longitudinal direction other end part of the length direction of an exterior body, and the negative electrode tab may be arrange | positioned.

  As shown in FIG. 1, the assembled battery 10 includes a first holder 30 attached to a front surface 11 a that is one end surface in the length direction of the battery stack 11, and a rear surface 11 b that is the other end surface in the length direction of the battery stack 11. And a second holder 50 attached to the. On the other hand, from the viewpoint of miniaturization of the assembled battery 10, no holder is provided on the side surface 11 c which is the end surface in the width direction of the battery stack 11.

  Specifically, the front surface 11a and the rear surface 11b of the battery stack 11 are covered with the first holder 30 and the second holder 50. On the side surface 11c of the battery stack 11, as shown in FIG. The seal portions 25b formed at both ends in the width direction of the exterior body 21 are exposed.

  The assembled battery 10 includes a case 60 that houses the battery stack 11 to which each of the holders is attached. The case 60 includes, for example, an upper case 63 and a lower case 73 and has a substantially rectangular parallelepiped shape corresponding to the shape of the battery stack 11. The upper case 63 and the lower case 73 are coupled using, for example, screws (not shown). In the example shown in FIG. 1, fixing portions 64 and 74 used for screwing are provided at the four corners of the upper case 63 and the lower case 73, respectively.

  In the present embodiment, the lower case 73 includes a front wall 73a and a rear wall 73b facing in the length direction, two side walls 73c facing in the width direction, and a bottom plate formed integrally with the side walls 73a, 73b, 73c. 73d. Each side wall 73a, 73b, 73c defines a substantially rectangular opening 73e that opens upward. The lower case 73 is deep enough to allow the side wall 73c to face substantially the entire side surface 11c of the battery stack 11 when the battery stack 11 is inserted and accommodated in the stacking direction from the opening 73e. (Ie, the height of the side wall).

  A plurality of protrusions 79 are formed on the inner surface of each side wall 73 c of the lower case 73. The plurality of protrusions 79 are formed to extend in parallel to each other and along the length direction. In the present embodiment, it is preferable that the number of protrusions 79 corresponding to the number of unit cells 20 constituting the battery stack 11 is formed. Each protrusion 79 is formed over substantially the entire length of the seal portion 25b formed on the side surface of each unit cell 20 when the battery stack 11 is accommodated in the lower case 73. Is preferred. The cross-sectional shape and function of the protrusion 79 will be described later.

  In addition, the protrusion 79 formed in the lower case 73 may not correspond to all the unit cells 20 constituting the battery stack 11, for example, every other unit cell 20 stacked. May be. Moreover, each protrusion 79 is not limited to the case where it forms continuously over the full length of the battery laminated body 11, and may be divided and formed in multiple in the length direction.

  In the present embodiment, a pair of output terminals 16 and 17 that are drawn out of the case 60 through the front surface 11a of the battery stack 11, and an insulating cover that is disposed between the front surface 11a and each of the output terminals 16 and 17. 18 are provided. The output terminal 16 is a positive output terminal connected to the positive tab 26, and the output terminal 17 is a negative output terminal connected to the negative tab 27. The insulating cover 18 has two output terminal insertion holes 18a and is fixed to the first holder 30 by a hook or the like (not shown).

  On the front surface of the upper case 63, two notches 67 for passing the output terminals 16, 17 are formed. In the example shown in FIG. 1, notches 67 are respectively formed on both sides of the front surface of the upper case 63 in the width direction. Two fastening portions 77 are provided in front of the lower case 73 so as to correspond to the respective notches 67. For example, the tip portions of the output terminals 16 and 17 drawn from the notches 67 are connected to the fastening portion 77. It is bolted.

  As shown in FIGS. 1 and 2, two openings 61 and 62 are preferably formed on the rear surface of the case 60. In the present embodiment, the two openings 61 and 62 are formed side by side in the width direction on the rear wall 73 b of the lower case 73. A substantially U-shaped flow path 100 (see FIG. 4) of cooling air is formed between the plurality of parallel blocks 13 constituting the assembled battery 10, and an opening is provided to flow the cooling air through the flow path 100, for example. 61 is an inlet for cooling air, and the opening 62 is an outlet for cooling air. The shape of the openings 61 and 62 is, for example, a square shape, but may be other shapes such as a circular shape.

  As shown in FIG. 3, the unit cell 20 constituting the battery stack 11 includes a power generation element including an electrode body and an electrolyte, an exterior body 21 that houses the power generation element, and one end portion in the length direction of the exterior body 21. A pair of extended electrode tabs, that is, a positive electrode tab 26 and a negative electrode tab 27 are provided. An example of the electrode body is a wound electrode body in which a positive electrode and a negative electrode are wound through a separator. The positive electrode tab 26 is connected to the positive electrode, and the negative electrode tab 27 is connected to the negative electrode. It is preferable to use a film in which a resin layer is formed on both surfaces of a metal layer for the laminate films 22 and 23 constituting the outer package 21. The metal layer is a thin film layer of aluminum, for example, and has a function of preventing permeation of moisture and the like.

  The exterior body 21 includes a flat main body 24 and a seal part 25 that extends from at least both ends in the length direction of the main body 24 and is formed by joining the edges of the laminate films 22 and 23. In the unit cell 20, the power generation element is accommodated in the main body 24. In the example shown in FIG. 3, a flat, substantially rectangular parallelepiped main body 24 is formed on the laminate film 22. The main body 24 is formed, for example, by drawing the laminate film 22 so as to be convex on the opposite side of the laminate film 23 disposed opposite to the main body portion 24. The seal portion 25 is formed around the main body portion 24 by heat-sealing the edge portions of the laminate films 22 and 23, for example.

  Below, regarding the seal portion 25 of the unit cell 20, the seal unit 25 extending from both ends in the length direction of the main body unit 24 and formed along the width direction of the unit cell 20 is referred to as a “seal unit 25 a”. The seal portion 25 extending along the length direction at both ends in the width direction of the main body portion 24 is referred to as a “seal portion 25b”. The seal portion 25b has a high rigidity because the two laminated films 22 and 23 are overlapped. Moreover, it is preferable that the width | variety of the seal | sticker part 25b is the same as the up-down direction length of the side surface 24c of the main-body part 24, for example, or a little short. By bending the seal portion 25b having such a high rigidity obliquely upward at the base end side, for example, the side surface 24c of the main body portion 24 is reinforced, and each unit from the lower case 73 is reinforced as described later. A function of suppressing removal of the battery 20 can be achieved.

  In the present embodiment, the seal portion 25 b formed along the length direction of the unit cell 20 is obliquely upward so as to form an acute angle with respect to the side surface 24 c that is the width direction end surface along the vertical direction of the main body portion 24. It is bent towards. In addition, the bent portion of the seal portion 25b bent in this way can flexibly change the bending angle with respect to the side surface 24c of the main body portion 24. Therefore, when the battery stack 11 is accommodated in the lower case 73, the above-mentioned angle is once reduced by the seal portion 25 b coming into contact with the protrusion 79 formed on the inner surface of the side wall of the lower case 73, and then restored again. You can return to the original angle. The seal portion 25 b bent in this way forms a part of a configuration that makes it difficult to take out the single cells 20 constituting the battery stack 11 housed in the lower case 73 from the lower case 73.

  The seal portion 25a is formed to extend in the length direction from the lower portion of the front surface 24a, which is the end surface on one side in the length direction, and the rear surface 24b, which is the end surface on the other side in the length direction. The width of the seal portion 25a is, for example, substantially the same as the width of the seal portion 25b, and is formed substantially perpendicular to the front surface 24a and the rear surface 24b of the main body portion 24. Since the seal portion 25a is formed by overlapping the two laminate films 22 and 23, the seal portion 25a has high rigidity and can be used for attaching the first holder 30 and the second holder 50.

  As described above, the positive electrode tab 26 and the negative electrode tab 27 both extend from one end in the length direction of the exterior body 21 (the front surface 24a side). That is, the pair of electrode tabs are pulled out of the exterior body 21 from the same surface (front surface 24 a) of the main body portion 24 through the seal portion 25 a. The positive electrode tab 26 and the negative electrode tab 27 are thin plate-like conductive members, and are arranged side by side in the width direction of the unit cell 20. In the example shown in FIG. 3, the positive electrode tab 26 is disposed on one end side in the width direction of the unit cell 20, and the negative electrode tab 27 is disposed on the other end side in the width direction of the unit cell 20. Between the positive electrode tab 26 and the negative electrode tab 27, a space is provided in which a connection portion 90 (see FIG. 4 and the like) of a pair of bus bars described later can be formed.

  The positive electrode tab 26 and the negative electrode tab 27 may have the same shape and the same size at least in a portion extending from the tip of the seal portion 25a to the outside of the exterior body 21 (hereinafter sometimes referred to as an “exposed portion”). preferable. The width direction length of each electrode tab is less than 50% of the width direction length of the main body portion 24, and preferably 20 to 40%. The length in the length direction of the exposed portion of each electrode tab is a length that does not hinder the connection with the bus bar, and is, for example, approximately the same as the width of the bus bar.

  In addition, the shape of the exposed part of each electrode tab is the unit cell 20 (unit cell 20x of FIG. 5 etc.) arrange | positioned above the parallel block 13 mentioned later, and the unit cell 20 arrange | positioned below the parallel block 13. FIG. (Single cell 20y in FIG. 5 and the like).

  With reference to FIGS. 4-6, the battery laminated body 11 is further explained in full detail. FIG. 4 is a diagram showing the battery stack 11 with the insulating cover 18 removed as viewed from the front. FIG. 5 is an exploded perspective view showing one of the parallel blocks 13 constituting the battery stack 11 as viewed from the front. 4 and 5, among the two unit cells 20 constituting the parallel block 13, the unit cell 20 disposed on the upper side is referred to as “unit cell 20x”, and the unit cell 20 disposed on the lower side is represented by “unit cell 20y”. And x and y are respectively attached to the constituent elements of each battery. Moreover, FIG. 6 is a figure which shows the battery laminated body 11 in the state seen from back.

  As shown in FIGS. 4-6, the battery laminated body 11 is comprised using the several cell 20 in which the main-body part 24 has the same shape and the same dimension. The number of unit cells 20 constituting the battery stack 11 is not particularly limited, but is preferably four or more. In the present embodiment, the battery stack 11 is composed of eight unit cells 20, and the battery stack 11 includes four parallel blocks 13 configured by connecting two unit cells 20 in parallel. The battery stack 11 is configured by stacking a plurality of unit cells 20 in the same direction as described above. Specifically, the front surface 24a of the main body 24 from which the positive electrode tab 26 and the negative electrode tab 27 are drawn faces in the same direction, and the positions of both the length direction both ends and the width direction both ends of the main body 24 match each other. Each unit cell 20 is laminated.

  As shown in FIG.4 and FIG.5, the parallel block 13 which comprises the battery laminated body 11 is comprised from two unit cells 20x and 20y. In the unit cells 20x and 20y, the main body portions 24x and 24y are preferably fixed to each other via the adhesive layer 28. For example, a double-sided tape can be applied to the adhesive layer 28. The parallel block 13 includes a positive electrode tab stack portion 14 formed by overlapping the positive electrode tabs 26 of the individual cells 20 constituting the block, and a negative electrode tab stack portion 15 formed by overlapping the negative electrode tabs 27. Have The positive electrode tab laminate portion 14 and the negative electrode tab laminate portion 15 may be formed so as to be substantially aligned in the width direction of the battery stack 11 in the central portion of the parallel block 13 in the vertical direction, that is, in the vicinity of the boundary between the single cells 20x and 20y. Is preferred. The battery stack 11 is attached with a positive bus bar 80 connected to the positive tab laminate 14 and a negative bus bar 85 connected to the negative tab stack 15.

  The battery stack 11 is configured by connecting a plurality of parallel blocks 13 in series using a pair of bus bars. That is, the connection form of the unit cells 20 in the assembled battery 10 is a series-parallel connection in which a series connection and a parallel connection are combined. However, the assembled battery 10 does not have the parallel connection of the single cells 20 and may have a structure that does not include the parallel block 13. In this case, the positive electrode side bus bar 80 is electrically connected to only the positive electrode tab 26 of one unit cell 20, and the negative electrode side bus bar 85 is electrically connected to only the negative electrode tab 27 of one unit cell 20. Connects the single cells 20 constituting the battery stack 11 in series. Note that the number of unit cells 20 constituting the parallel block 13 may be three or more.

  Each of the pair of bus bars is a metal conductive member, and is connected to the positive electrode tab laminate portion 14 and the negative electrode tab laminate portion 15 by welding, for example. The positive electrode side bus bar 80 has a first connection part 81, a second connection part 82, and a connection part 83, and is preferably configured by bending one metal plate. The first connection portion 81 is a portion connected to the positive electrode tab laminate portion 14. The second connection portion 82 is a portion that extends substantially parallel to the first connection portion 81 and is connected to the negative electrode bus bar 85 of another parallel block 13. For example, the positive electrode side bus bar 80 has a constant width over its entire length, and the first connection portion 81 is longer than the second connection portion 82. The connection part 83 is a part which connects each connection part, Comprising: A level | step difference is formed between each connection part.

  The first connecting portion 81 extends from one end of the connecting portion 83 and the second connecting portion 82 extends from the other end of the connecting portion 83 in opposite directions. The connecting portion 83 is preferably formed substantially perpendicular to each connecting portion. In this embodiment, the 1st connection part 81 is welded to the upper surface of the positive electrode tab lamination | stacking part 14, is located in the up-down direction approximate center part of the parallel block 13, and the 2nd connection part 82 is located in the upper end part of the parallel block 13. . The connecting part 83 forms a step between the connecting parts.

  Similarly to the positive electrode side bus bar 80, the negative electrode side bus bar 85 has a first connection part 86, a second connection part 87, and a connection part 88, and is configured by bending one metal plate. preferable. The second connecting portion 87 is connected to the positive bus bar 80 of another parallel block 13. In the present embodiment, the first connection portion 86 is welded to the lower surface of the negative electrode tab laminate portion 15 and is positioned at a substantially central portion in the vertical direction of the parallel block 13, and the second connection portion 87 is positioned at the lower end portion of the parallel block 13. . The connection part 88 forms the level | step difference concerning between each connection part.

  The pair of bus bars may have different shapes and dimensions, but preferably have the same shape and dimensions. The positive electrode side bus bar 80 and the negative electrode side bus bar 85 differ only in the direction in which they are attached to the battery stack 11, and a member used as the positive electrode side bus bar 80 can be used as the negative electrode side bus bar 85. In this case, the assembled battery 10 can be configured using one type of bus bar, and the number of parts can be reduced.

  The adjacent parallel blocks 13 are connected in series using the positive electrode side bus bar 80 and the negative electrode side bus bar 85 as described above. The connecting portion 90 between the positive electrode side bus bar 80 and the negative electrode side bus bar 85, which is an electrical connecting portion between the parallel blocks 13, is, for example, the second connecting portion 87 of the negative electrode side bus bar 85 and the second connecting portion 82 of the positive electrode side bus bar 80. Are overlapped and welded to form the vicinity of the boundary between the two parallel blocks 13. A plurality of connection portions 90 are preferably formed side by side in the vertical direction on the front surface 11 a of the battery stack 11.

  The first holder 30 is attached to the front surface 11a of the battery stack 11 as described above. A plurality of first holders 30 are provided side by side in the stacking direction (vertical direction) of the unit cells 20, and the adjacent holders are connected to each other. That is, the plurality of first holders 30 connected to each other hold one end of the battery stack 11 in the length direction. For example, the first holder 30 is attached to one parallel block 13 at a ratio of one. In the present embodiment, since the battery stack 11 is composed of four parallel blocks 13, four first holders 30 are attached to the battery stack 11. Each first holder 30 has the same shape and the same dimensions.

  The first holder 30 has an opening 31 through which the positive electrode tab 26 and the negative electrode tab 27 of the unit cell 20 are passed. The positive electrode tab 26 is pulled out to the front side (opposite side of the main body portion 24) of the first holder 30 through the opening 31, and the positive tab 26 of another unit cell 20 constituting the same parallel block 13 that is similarly drawn out. At the same time, the positive electrode tab laminated portion 14 is formed. Similarly to the positive electrode tab 26, the negative electrode tab 27 is pulled out to the front side of the first holder 30 through the opening 31 to form the negative electrode tab stacked portion 15.

  Although the number of openings 31 may be one, in this embodiment, two openings 31 that pass through the electrode tabs are formed on each side of the first holder 30 in the width direction. The two openings 31 are formed side by side in the width direction at substantially the center in the vertical direction of each first holder 30, and are also formed in the width direction between adjacent first holders 30.

  The first holder 30 preferably has a support portion 32 that supports the positive bus bar 80 and the negative bus bar 85. The support portion 32 is formed between the two openings 31 with the center portion in the width direction of the first holder 30 protruding in the length direction. In the present embodiment, the support portions 32 of the four first holders 30 are arranged in the vertical direction, and the positive bus bar 80 and the negative bus bar 85 are sandwiched between the adjacent parallel blocks 13. More specifically, each support portion 32 sandwiches the connection portion 90 of the pair of bus bars. For this reason, for example, breakage of the connection portion 90, poor contact, and the like hardly occur, and a good connection state is maintained for a long time.

  The first holder 30 may be composed of one member, but is preferably composed of two fixing members 33 and 43. The fixing members 33 and 43 sandwich the seal portion 25a of the unit cell 20 from above and below while being connected to each other. The fixing members 33 and 43 are used for connecting the rectangular bar-like main body portions 34 and 44 that are long in the width direction, and the overhang portions 35 and 45 that protrude in the length direction from the center portions in the width direction of the main body portions. Engaging portions 37 and 47, respectively. The overhang portions 35 and 45 are in contact with each other and overlap in the vertical direction to form a support portion 32 that sandwiches the bus bar connection portion 90. The engaging portions 37 and 47 are preferably provided at both ends in the width direction of the main body portions 34 and 44, respectively. An example of a suitable structure of the engaging portions 37 and 47 is a structure in which a hook 47 a of the engaging portion 47 is hooked on the engaging portion 37 and fixed.

  The main body portion 34 of the fixing member 33 is disposed on the seal portion 25ax of the unit cell 20x, and is disposed in a portion surrounded by the seal portion 25ax, the seal portion 25by bent upward, and the front surface 24ax of the main body portion 24x. . The main body portion 44 of the fixing member 43 is disposed on the seal portion 25ay of the unit cell 20y, and is disposed in a portion surrounded by the seal portion 25ay, the seal portion 25by bent upward, and the front surface 24ay of the main body portion 24y. . And the seal | sticker part 25ax of the cell 20x is pinched | interposed by the fixing members 33 and 43 from the upper and lower sides. The seal portion 25ay of the unit cell 20y is sandwiched between the fixing member 43 disposed on the seal portion and the fixing member 33 of another first holder 30 disposed below the seal portion.

  In this embodiment, the protrusions 47b and the like provided at both ends in the width direction of the main body 44 are used to prevent the positional deviation between the adjacent first holders 30 in the length direction and the width direction. On the other hand, the first holder 30 does not have a structure that is fixed so as not to be displaced in the vertical direction with respect to another first holder 30 arranged in the vertical direction, and the plurality of first holders 30 arranged in the vertical direction have the insulating cover 18. (See FIG. 1 etc.). The fixing members 33 and 43 have cover insertion ports 34b and 47c for attaching the insulating cover 18, respectively. The cover insertion port 34 b is formed in the main body 34 of the fixing member 33, and the cover insertion port 47 c is formed in the engaging portion 47 of the fixing member 43.

  As shown in FIGS. 5 and 6, the second holder 50 is attached to the rear surface 11 b of the battery stack 11 as described above. A plurality of second holders 50 are provided side by side in the vertical direction, and adjacent holders are connected to each other. That is, the plurality of second holders 50 connected to each other hold the other end in the vertical direction of the battery stack 11. In the present embodiment, the second holder 50 is attached to one parallel block 13 at a ratio of one. The second holders 50 have the same shape and the same dimensions.

  At least one of the second holder 50 and the adjacent second holder 50 has an inlet 51 for introducing cooling air into the flow path 100 formed between the adjacent unit cells 20, and the flow path 100. It is preferable that a discharge port 52 for discharging the cooling air from is provided. In the present embodiment, the inlet 51 and the outlet 52 are formed side by side between the adjacent second holders 50. That is, an inlet 51 and an outlet 52 are formed for each parallel block 13. The horizontal lengths of the inlet 51 and the outlet 52 are, for example, substantially the same. The introduction port 51 is disposed on the other lateral end of the second holder 50, and the discharge port 52 is disposed on one lateral end of the second holder 50. The respective introduction ports 51 and the respective discharge ports 52 are arranged in the vertical direction. Has been placed.

  The second holder 50 may be composed of a plurality of members similarly to the first holder 30, but is preferably composed of one member from the viewpoint of reducing the number of parts. Since there is no electrode tab or the like on the rear surface 11b of the battery stack 11, even the second holder 50 formed integrally can be easily attached.

  Similar to the first holder 30, the second holder 50 has a rectangular bar-shaped main body portion 53 that is long in the horizontal direction, a protruding portion 54 that protrudes in the vertical direction from the horizontal central portion of the main body portion 53, and an adjacent second holder. 50 and an engaging portion 55 used for connection with 50. The overhang portion 54 is connected to the overhang portion 54 of the second holder 50 that is disposed above and below. Thereby, the supply flow path for flowing the cooling air introduced from the opening 61 of the case 60 to the plurality of flow paths 100 of the battery stack 11, and the exhaust for flowing the cooling air exhausted from these flow paths 100 to the opening 62 A partition 103 that partitions the flow path is formed.

  The engaging portions 55 are preferably provided on both lateral sides of the main body portion 53. The engaging portion 55 has, for example, a hook 55 a protruding downward and an insertion port 55 b formed in the upper portion of the second holder 50. The hook 55a of the second holder 50 arranged on the upper side is inserted into the insertion port 55b of the second holder 50 arranged on the lower side, and the adjacent second holders 50 are connected to each other.

  The second holder 50 has two holding portions 56 and 57 that sandwich the seal portion 25a of the unit cell 20 from above and below. Between each holding | maintenance part 56 and 57, the groove | channel 58 in which the seal | sticker part 25a is inserted is formed. In other words, the two holding portions 56 and 57 are formed by the groove 58 formed in the main body portion 53. The groove 58 is formed on the back side of the second holder 50. The groove 58 is preferably formed over the entire length in the lateral direction of the main body 53.

  Next, with reference to FIG. 7, the cross-sectional shape of the protrusion 79 formed in the inner surface of the side wall 73c of the lower case 73 in the assembled battery 10 of this embodiment and its function will be described. 7 is a partial cross-sectional view taken along line AA in FIG.

  As shown in FIG. 7, in this embodiment, the protrusion 79 formed on the inner surface of the side wall 73c of the lower case 73 has a substantially square cross section. The lower surface of the projection 79 constitutes an engagement surface with which the tip of the seal portion 25 b of each unit cell 20 is engaged when the battery stack 11 is accommodated in the lower case 73. In the present embodiment, an example is shown in which the engagement surface is formed on a flat surface protruding in a direction substantially orthogonal to the side wall 73c. However, the engagement surface may be formed to be inclined obliquely downward so as to form an acute angle with respect to the side wall 73c, or may be formed as a surface that forms a catch portion that opens downward. Moreover, the cross-sectional shape of the protrusion 79 is not limited to a substantially square shape, and may be formed in other shapes such as a rectangular shape, a triangular shape, and a quarter arc shape.

  Subsequently, the function of the protrusion 79 described above will be described. When the battery stack 11 is inserted in the stacking direction from above through the opening 73e of the lower case 73 and accommodated in the case, as shown in FIG. The seal portion 25b contacts the protrusion 79 on the side wall 73c. At this time, the seal portion 25b bent obliquely upward can be elastically changed in angle with respect to the side surface 24c of the main body portion 24. Therefore, as shown in FIG. As a result, the body portion 24 bends so that the bending angle with respect to the side surface 24c becomes small.

  And when the battery laminated body 11 is completely accommodated in the lower case 73, as shown in FIG.7 (b), the seal | sticker part 25b of each single battery 20 will restore | restore elastically in the original angle state, The distal end portion 29 of the seal portion 25 b engages with an engagement surface that is the lower surface of the protrusion 79. As a result, the seal portions 25 b of all the unit cells 20 of the battery stack 11 are engaged with the protrusions 79 of the side walls 73 c of the lower case 73. Therefore, once the battery stack 11 is accommodated in the lower case 73, it becomes difficult to take out each unit cell 20 from the opening 73e of the lower case 73. As a result, it is difficult to disassemble the assembled battery 10 for mischief purposes. .

  Moreover, in this embodiment, since the protrusion 79 is extended and formed along the bent seal part 25b of each cell 20, the seal part 25b engages with the protrusion 79 over substantially the entire length. Therefore, the effect of making it difficult to take out the unit cell 20 from the lower case 73 can be further enhanced. Furthermore, in this embodiment, since the protrusion 79 is provided corresponding to all the unit cells 20 constituting the battery stack 11, the effect of making it difficult to remove the battery 20 from the lower case 73 can be further enhanced. it can.

  Next, with reference to FIG.8 and FIG.9, the assembled battery 10a which is another example of this embodiment is demonstrated. FIG. 8 is an exploded perspective view showing the assembled battery 10a as viewed from the front. FIG. 9 is a partial cross-sectional view corresponding to FIG. 7 in the assembled battery 10a. Here, points different from the assembled battery 10 which is an example of the above-described embodiment will be mainly described, and the same components are denoted by the same reference numerals and redundant description is omitted.

  As shown in FIG. 8, the assembled battery 10 a includes a battery stack 11 and an upper case 63 and a lower case 73 that accommodate the battery stack 11. The configuration of the battery stack 11 is substantially the same as that of the assembled battery 10 described above. However, the seal portion 25b of the unit cell 20 constituting the battery stack 11 is different from the assembled battery 10 in that it is formed in a state of being bent obliquely downward as shown in FIG. Further, in the assembled battery 10a, the end positions of the pair of output terminals 16 and 17 attached to the battery stack 11 are set around the center position in the vertical direction of the battery stack 11, so It is different from the assembled battery 10 in which the end position of the output terminal is set.

  In the present embodiment, the upper case 63 includes a front wall 63a and a rear wall 63b that face in the length direction, two side walls 63c that face in the width direction, and a ceiling formed integrally with the side walls 63a, 63b, and 63c. A plate 63d is provided. Each side wall 63a, 63b, 63c defines a substantially rectangular opening 63e that opens upward. Further, the upper case 63 has a depth (that is, the side of the side wall 63c) that the side wall 63c faces substantially the entire side surface 11c of the battery stack 11 when the battery stack 11 is inserted and accommodated from the opening 63e. Height).

  On the other hand, the lower case 73 is formed so that the height in the vertical direction is lower than that of the upper case 63. Therefore, the openings 61 and 62 formed on the rear surface of the case 60 are formed as two substantially rectangular cutout portions 61 a and 62 a on the rear wall 73 b of the lower case 73, and are formed on the rear wall 63 b of the upper case 63. The openings 61 and 62 are formed in combination with the two notches (not shown).

  A plurality of protrusions 79 are formed on the inner surface of each side wall 63c of the upper case 63, as shown in FIG. The number and shape of the protrusions 79 are the same as those of the assembled battery 10 described above.

  Next, the function of the protrusion 79 of the upper case 63 in the assembled battery 10a will be described with reference to FIG. In the assembled battery 10a, the battery stack 11 is first placed on the lower case 73, and then the upper case 63 is placed over the battery stack 11. In this embodiment, the battery stack 11 is the upper case. It is inserted into the opening 63e of 63 along the stacking direction from below.

  At this time, as shown in FIG. 9A, the seal portion 25b of each unit cell 20 constituting the battery stack 11 comes into contact with the protrusion 79 on the side wall 63c. Since the angle of the sealing portion 25b bent obliquely downward is elastically changeable with respect to the side surface 24c of the main body 24, the main body is pressed by the protrusion 79 as shown in FIG. The part 24 bends so that the bending angle with respect to the side surface 24c becomes small.

  And when the battery laminated body 11 is completely accommodated in the upper case 63, as shown in FIG.9 (b), the seal | sticker part 25b of each cell 20 will be restored | restored to an original angle state elastically, The distal end portion 29 of the seal portion 25 b engages with the engagement surface that is the upper surface of the protrusion 79. Accordingly, the seal portions 25b of all the unit cells 20 of the battery stack 11 are engaged with the protrusions 79 on the side wall 63c of the upper case 63. Therefore, once the battery stack 11 is accommodated in the upper case 63, it becomes difficult to take out each unit cell 20 from the opening 73e of the upper case 63, and as a result, it is difficult to disassemble the assembled battery 10 for mischief purposes. . Other functions and effects are the same as those of the assembled battery 10.

  Note that the present invention is not limited to the above-described embodiment and its modifications, and various modifications and improvements can be made within the scope of matters described in the claims of the present application and equivalents thereof. Needless to say.

  10, 10a battery pack, 11 battery stack, 13 parallel block, 16, 17 output terminal, 18 insulation cover, 20 cell, 21 exterior body, 22, 23 laminate film, 24 body part, 25, 25a, 25b seal part 26, positive electrode tab, 27 negative electrode tab, 29 tip, 30 first holder, 50 second holder, 60 case, 63 upper case, 73 lower case, 63c, 73c side wall, 79 protrusion.

Claims (4)

An exterior body composed of a sheet material, which has a flat main body portion that houses a power generation element, and a seal portion that is formed by joining edges of the sheet material at the end of the main body portion. A battery stack configured by stacking a plurality of unit cells including an outer package and a pair of electrode tabs extending from an end of the outer package;
A case having at least two opposite side walls and a bottom plate or a top plate, and inserting and storing the battery stack along the stacking direction from an opening defined by the side walls;
The sealing part of the unit cell constituting the battery stack is bent so that the bending angle with respect to the main body part can be elastically changed at the end of the exterior body where the pair of electrode tabs are not provided,
On the inner surface of the side wall of the case, a protrusion is formed that engages the tip of the bent seal portion of the unit cell.
Assembled battery. The assembled battery according to claim 1,
The projecting portion is an assembled battery formed by extending along a bent seal portion of the unit cell. The assembled battery according to claim 1 or 2,
The projecting portion is an assembled battery provided corresponding to all the single cells constituting the battery stack. The assembled battery according to any one of claims 1 to 3,
The assembled battery, wherein an engagement surface of the protruding portion with which an end portion of the bent sealing portion of the unit cell engages is formed on a plane protruding in a direction substantially orthogonal to the side wall.

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