JP2018170179A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device capable of contributing to cost reduction, while satisfying the request of reliability regarding safety.SOLUTION: A power storage device 1 where an exterior body 15 is constituted of laminate films 16, 17 for housing battery elements 11, 12, an opening for exposing the current-carrying parts 13, 14 of the battery elements 11, 12 is formed in the exterior body 15, and multiple battery cells 10 each having a first through hole 18 formed in the fusion areas 16b, 17b of the laminate film are laminated so that the current-carrying parts 13, 14 come into contact with each other, includes an enclosure 20 for housing the multiple battery cells 10 laminated without providing a spacer, a pillar member 30 composed of resin and penetrating the first through holes 18 of the multiple battery cells 10, and second through holes 22 provided in the enclosure 20, and to which the end 31 of the pillar member 30 is heat welded. Cross-sectional area of the first through hole 18 is equal to or less than the cross-sectional area of the pillar member 30 in the width direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electricity storage device.

  As one form of battery, a so-called pouch-type battery cell is known in which a battery element is sandwiched between two laminated films. In general, a pouch-type battery cell has a flat shape, and is formed such that a sheet-like electrode terminal protrudes between two laminate films. In addition, as disclosed in, for example, Patent Document 1, a pouch-type battery cell is often used by configuring a power storage device having a desired charge / discharge capacity by stacking a plurality of battery cells.

  More specifically, the external configuration of the pouch-type battery cell includes a covering region that houses the battery element, and a fusion region in which the two laminated films are fused and sealed around the covering region. . In the prior art according to Patent Document 1, through holes are formed in the fusion region of the battery cells, and a plurality of spacers and a plurality of the battery cells in which the through holes are also formed are alternately stacked, and these through holes An electricity storage device is disclosed which is configured integrally with a fixing pillar provided so as to penetrate through the battery. With the spacer, it is possible to connect the electrode terminal protruding from each battery cell and the charge / discharge line while preventing the electrode terminals of each battery cell from being short-circuited.

JP 2008-269926 A

  By the way, an electricity storage device as described above may be mounted on a moving body that generates vibration during movement, such as an electric vehicle or an aircraft. However, the power storage device must have a robust configuration in order to satisfy the reliability requirement for vibration input when mounted from the viewpoint of safety, which may increase the manufacturing cost.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide an electricity storage device that can contribute to cost reduction while satisfying the requirement of reliability related to safety. is there.

  In order to achieve the above-described object, an electricity storage device according to the present invention is configured such that an exterior body is composed of a laminate film that houses a battery element, and an opening that exposes a conductive portion of the battery element is formed in the exterior body. A battery device in which a plurality of battery cells, in which a first through hole is formed in a fusion region at the periphery of the battery element and the laminate film is fused, are stacked so that the conductive portions are in contact with each other. A housing that accommodates the plurality of battery cells stacked without a spacer, a column member that is made of resin and passes through the first through holes of the plurality of battery cells, and the housing. And a second through hole in which an end portion of the pillar member is thermally welded, and the cross sectional area of the first through hole is equal to or smaller than the cross sectional area in the width direction of the pillar member. .

  According to the electricity storage device of the present invention, the plurality of battery cells are stacked without providing a spacer between the battery cells, because the conductive part of each battery cell is exposed from the opening formed in the exterior body. can do. Moreover, the cross-sectional area of the 1st through-hole formed in the fusion | melting area | region of a battery cell is below the cross-sectional area in the width direction of a pillar member. As a result, the stacked battery cells are both restricted from displacement in the horizontal direction and the vertical direction with respect to the housing via the column member. Thereby, according to the electricity storage device according to the present invention, it is possible to contribute to cost reduction through reduction of the number of parts and simplification of the manufacturing process by realizing the spacer-free structure while satisfying the reliability requirement regarding safety. An electricity storage device can be provided.

It is sectional drawing which shows the structure of the electrical storage device which concerns on this invention. It is sectional drawing which shows typically the internal structure of the battery module which concerns on this invention. It is a top view which shows the external appearance of the battery module which concerns on this invention. It is a perspective view which shows the structure of the battery cell which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the content demonstrated below, In the range which does not change the summary, it can change arbitrarily and can implement. In addition, the drawings used for the description of the embodiments schematically show constituent members, and are partially emphasized, enlarged, reduced, or omitted to deepen the understanding. In some cases, the scale, shape, and the like are not accurately represented.

  FIG. 1 is a cross-sectional view showing a configuration of an electricity storage device 1 according to the present invention. The power storage device 1 is, for example, a battery device that can be mounted on a vehicle to discharge and supply electric power necessary for traveling of the vehicle and to charge regenerative energy generated when the vehicle is decelerated.

  The power storage device 1 includes a plurality of battery modules 2, a plurality of attachments 3, an end plate 4, a bus bar 5, and a stack connector 6.

  As will be described in detail later, the battery module 2 accommodates a plurality of battery cells 10 and restricts the displacement of the battery cells 10 with respect to input vibration. In the present embodiment, the stack is constituted by four battery modules 2, but the number of battery modules 2 is not limited to four.

  The attachment 3 is for fixing two battery modules 2 arranged adjacent to each other at a predetermined interval, or fixing the battery modules 2 arranged adjacent to each other and the end plate 4 to each other at a predetermined interval. It is a member.

  The end plate 4 is disposed so as to sandwich a stack composed of a plurality of stacked battery modules 2 from above and below, and fixes the power storage device 1 to, for example, a mounted vehicle. Further, the end plate 4 is made of an insulating material and incorporates a conductive bus bar 5 and a stack connector 6. One end of the bus bar 5 is connected to, for example, a power control device for a vehicle (not shown), and transfers power between the power storage device 1 and the power control device for the vehicle. The battery cell 10 is charged / discharged by being connected to the electrode terminal of the battery cell 10 adjacent to the plate 4. That is, the two bus bars 5 included in the power storage device 1 serve as a positive electrode and a negative electrode for charging and discharging the power storage device 1, respectively.

  Next, the configuration of each battery module 2 will be described. FIG. 2 is a cross-sectional view schematically showing the internal configuration of the battery module 2 according to the present invention. FIG. 3 is a top view showing the external appearance of the battery module 2 according to the present invention.

  The battery module 2 includes a plurality of battery cells 10, a housing 20, a pillar member 30, and a module connector 40.

  The battery cell 10 can store electricity by housing therein a battery element composed of an electrode body 11 and an electrolyte 12 that are formed by laminating a positive electrode plate, a negative electrode plate, and a separator (not shown). In the present embodiment, four battery cells 10a to 10d are stacked, and these battery cells 10a to 10d are connected to each other in series.

  The battery cell 10 transmits and receives electric power through a positive terminal 13 and a negative terminal 14 formed on the front and back sides, respectively. Among the stacked battery cells 10, the battery cell 10 a disposed at the uppermost portion has the positive electrode terminal 13 disposed at two positions sandwiching the central portion on the upper surface, and the negative electrode terminal 14 disposed at one central portion on the lower surface. ing. Of the stacked battery cells 10, the battery cell 10 d disposed at the bottom of the battery cell 10 has a positive electrode terminal 13 disposed at one central portion on the upper surface and negative electrode terminals 14 disposed at two positions sandwiching the central portion on the lower surface. Has been placed. Of the stacked battery cells 10, the battery cells 10 b and 10 c arranged in the middle part have a positive electrode terminal 13 and a negative electrode terminal 14 arranged at one central part on the upper and lower surfaces, respectively.

  Here, generally, a battery cell expands and contracts with charge and discharge, and the amount of displacement of the thickness becomes maximum at the center of the battery cell. As described above, in the power storage device 1 according to the present invention, in the stacked battery cells 10, the two battery cells 10 arranged adjacent to each other have the positive electrode terminal 13 and the negative electrode terminal 14 of the battery cell 10. Connected at the center. Therefore, even when the thickness increases as each battery cell 10 expands, the conduction state of the two battery cells 10 disposed adjacent to each other can be favorably maintained. In addition, when connecting between each battery cell 10 electrically, the positive electrode terminal 13 and the negative electrode terminal 14 are not essential structures. The film thickness of the laminate film, which is the outer package of the battery cell, is generally several tens of μm, and even when stacked without passing through the positive electrode terminal 13 and the negative electrode terminal 14, electrical connection between the battery cells 10 is achieved. Is not inhibited. Therefore, sufficient electrical connection can be obtained (not shown) by laminating the portions where the electrode bodies 11 of each battery cell 10 are exposed to face each other.

  The casing 20 is formed in a box shape by a rigid member and accommodates the four battery cells 10a to 10d that are stacked. The casing 20 is formed with a leaf spring portion 21 so as to narrow the width in the vertical direction in the vicinity of the central portion of the upper surface and the lower surface. The leaf spring portion 21 fixes the stacked four battery cells 10a to 10d by sandwiching them from the vertical direction. In the present embodiment, the two leaf spring portions 21 press toward the inside of the housing 20 on the upper surface of the battery cell 10a disposed at the top and the lower surface of the battery cell 10d disposed at the bottom. . Note that an adhesive (not shown) is applied to the pressing surface.

  The column member 30 is made of a resin material, and is provided through the first through holes 18 formed in each battery cell 10 as will be described in detail later. The column member 30 has an end 31 protruding outward from the second through hole 22 formed in the housing 20 and is fixed to the housing 20 around the second through hole 22 by heat welding. Here, since the column member 30 is formed of a resin material, even if a conductive portion is exposed in the first through hole 18 of each battery cell 10, the battery cell 10 is prevented from being short-circuited. Can do. Further, since the column member 30 is fixed to the casing 20 by thermal welding, it can be fixed to the casing 20 without introducing other members, thereby reducing the material cost and simplifying the manufacturing process. Yield can be improved.

  The module connector 40 is made of a conductive member, and is formed as a conduction path for electrically conducting the inside and outside of the housing 20. More specifically, the module connector 40 disposed on the upper surface of the housing 20 is connected to the positive terminal 13 of the battery cell 10a disposed at the top in the housing 20, as shown in FIGS. One end is connected, and the other end protrudes to the outside of the case 20 through a third through hole 23 formed on the upper surface of the case 20. Further, the module connector 40 disposed on the lower surface of the housing 20 is formed on the lower surface of the housing 20 with one end connected to the negative electrode terminal 14 of the battery cell 10d disposed at the bottom inside the housing 20. The other end protrudes outside the housing 20 through the third through hole 23.

  In addition, when the plurality of battery modules 2 are configured as a stack, the other end of the module connector 40 is connected to the opposing module connector 40 or the stack connector 6 as shown in FIG. It becomes possible. In addition, it is preferable that the end of the module connector 40 is adhere | attached by the structure which does not impair electroconductivity between the positive electrode terminal 13 or the negative electrode terminal 14 to be connected. Needless to say, the module connector 40 may be provided directly in a portion where the electrode body 11 is exposed without passing through the positive electrode terminal 13 and the negative electrode terminal 14.

  Next, the configuration of each battery cell 10 will be further described. FIG. 4 is a perspective view showing the configuration of the battery cell 10 according to the present invention.

  In this embodiment, the battery cell 10 includes a battery element including the electrode body 11 and the electrolyte 12 described above, and an exterior body 15 that houses the battery element. The battery element may be a secondary battery or a primary battery, and may be a capacitor such as a capacitor.

  The exterior body 15 is formed by laminating an upper surface laminate film 16 and a lower surface laminate film 17. Further, the upper surface laminate film 16 and the lower surface laminate film 17 are respectively coated regions 16a and 17a that cover the battery element from both sides, and a fusion region 16b that fuses the upper surface laminate film 16 and the lower surface laminate film 17 at the periphery of the battery element. , 17b.

  The upper surface laminate film 16 is formed with an opening that exposes the positive electrode terminal 13 of the battery cell 10 and constitutes a conductive portion in a part of the covering region 16a. Here, an adhesive 50 is applied around the opening that exposes the positive electrode terminal 13.

  The bottom laminate film 17 has an opening that exposes the negative electrode terminal 14 of the battery cell 10 and has a configuration similar to that of the top laminate film 16, and constitutes a conductive portion in a part of the covering region 17a. An adhesive 50 (not shown) is applied around the opening that exposes the negative electrode terminal 14.

  Two battery cells 10 arranged adjacent to each other among the plurality of stacked battery cells 10 are in contact with the positive electrode terminal 13 of one battery cell 10 and the negative electrode terminal 14 of the other battery cell 10, and around it. A good contact state can be maintained by the applied adhesive 50.

  In the upper surface laminate film 16 and the lower surface laminate film 17, four first through holes 18 penetrating the fusion regions 16b and 17b are formed in each battery cell 10 in the present embodiment. And while making the pillar member 30 penetrate through each 1st through-hole 18 of the some battery cell 10 laminated | stacked, as mentioned above, each pillar with respect to the housing | casing 20 is fixed to the housing | casing 20. The horizontal displacement of the battery cell 10 can be regulated.

  Further, the cross-sectional area of the first through hole 18 is equal to or smaller than the cross-sectional area in the width direction of the column member 30. That is, the column member 30 penetrates the first through hole 18 so as to be press-fitted. Thereby, the pillar member 30 can regulate the displacement of each battery cell 10 in the vertical direction with respect to the housing 20. In the present embodiment, the cross-sectional shapes of the first through hole 18 and the column member 30 are circular, but the vertical displacement is caused by penetrating the column member 30 so as to press fit into the first through hole 18. The cross section of the 1st through-hole 18 and the pillar member 30 may be another shape as long as it is regulated.

  As described above, in the electricity storage device 1 according to the present invention, the positive electrode terminal 13 or the negative electrode terminal 14 as the conductive portion is formed in the covering regions 16a and 17a of the battery cell 10, and the plurality of battery cells 10 to be stacked are provided. Both horizontal and vertical displacements with respect to the housing 20 are regulated via the column member 30. Thereby, it is not necessary to provide a spacer between the battery cells 10 and the number of parts can be reduced, so that the part cost can be reduced. Moreover, since it is the simple structure which fixes the some battery cell 10 laminated | stacked to the housing | casing 20 only by the pillar member 30, it becomes possible to reduce the manufacturing cost accompanying simplification of a manufacturing process.

  Furthermore, since the electrical storage device 1 according to the present invention restricts the displacement of the stacked battery cells 10 with respect to the housing 20, it is reliable even when mounted on a moving body that generates vibration input. Safety can be ensured without impairing performance. Therefore, according to the electricity storage device 1 according to the present invention, it is possible to contribute to cost reduction while satisfying the requirement of reliability related to safety.

DESCRIPTION OF SYMBOLS 1 Power storage device 10 Battery cell 11 Electrode body (battery element)
12 Electrolyte (battery element)
13 Positive terminal (conductive part)
14 Negative terminal (conductive part)
DESCRIPTION OF SYMBOLS 15 Exterior body 16 Upper surface laminated film 17 Lower surface laminated film 16a, 17a Covering area | region 16b, 17b Fusion | fusion area | region 18 1st through-hole 20 Case 22 2nd through-hole 30 Column member 31 End part

Claims (1)

The exterior body is composed of a laminate film that accommodates the battery element, and an opening is formed in the exterior body to expose the conductive portion of the battery element. A plurality of battery cells in which a first through hole is formed in a wearing region is an electricity storage device that is stacked such that the conductive portions are in contact with each other,
A housing for accommodating the plurality of battery cells stacked without providing a spacer;
A column member made of resin and penetrating through the first through holes of the plurality of battery cells;
A second through hole provided in the housing and to which an end of the pillar member is thermally welded,
The cross-sectional area of the said 1st through-hole is below the cross-sectional area in the width direction of the said column member, The electrical storage device characterized by the above-mentioned.

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