JP2018200856A - Power storage device - Google Patents

Abstract

To provide a power storage device capable of contributing to a cost reduction while satisfying a request for reliability of the device.SOLUTION: A power storage device includes: a laminate structure 10 in which a plurality of battery cells 10a to 10d, each of which includes an exterior body 15 constituted by laminate films 16, 17 opposite to each other, the exterior body housing battery elements 11, 12, and has first apertures 19, at which a positive electrode terminal 13 and a negative electrode terminal 14 are exposed on the laminate films 16, 17, respectively, are laminated so that a positive electrode terminal 13 and a negative electrode terminal 14 are brought into contact with each other; a housing 20 for housing the laminate structure 10; a second aperture 21 provided on the housing 20 so as to face a positive electrode terminal 13 or a negative electrode terminal 14 of the laminate structure 10; an insulation member 41 provided at the circumference of the second aperture 21; and an elastic member 42 that is electrically connected to the positive electrode terminal 13 or the negative electrode terminal 14 and is supported by the insulation members 41.SELECTED DRAWING: Figure 4

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. Further, a pouch-type battery cell is often used by forming a power storage device having a desired charge / discharge capacity by stacking a plurality of battery cells.

  On the other hand, by forming a metal exposed portion that exposes the conductive portion of the battery element in a planar shape at the center of the laminate film constituting the exterior body, the battery cell that uses the metal exposed portion as a soldering portion or a conductive portion Is disclosed in Patent Document 1.

JP2015-228365A

  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 circumstances, and an object of the present invention is to provide a power storage device that can contribute to cost reduction while satisfying the reliability requirement of the device. .

  In order to achieve the above-described object, an electricity storage device according to the present invention is composed of a laminate film in which an exterior body houses a battery element and has a first surface and a second surface facing the first surface. A plurality of battery cells in which a first opening that exposes the conductive portion of the battery element on each of the first surface and the second surface is formed in the outer package so that the conductive portion contacts each other. A stacked structure in which the conductive portions are exposed at both end surfaces in the stacking direction, a housing that houses the plurality of battery cells, and the housing so as to face the conductive portions of the stacked structure. A second opening provided in the first opening, an insulating member provided at a periphery of the second opening, and an elastic member electrically connected to the conductive portion and supported by the insulating member. Power storage device A.

  The housing of the electricity storage device accommodates a laminated structure in which a plurality of battery cells having conductive portions formed on both surfaces of an exterior body made of a laminate film are laminated. The housing of the electricity storage device is provided with a second opening so as to face the conductive parts exposed at both end faces in the stacking direction of the stacked structure, and the second opening is elastic with conductivity through an insulating member. The member is supported. As a result, according to the electricity storage device of the present invention, the laminated structure housed in the casing is restricted from displacement in the stacking direction by the elastic member, and the elastic member functions as an electrode terminal for conducting the inside and outside of the casing. To do. Therefore, the electricity storage device can stably support the laminated structure on the housing against vibration input from the outside, and the elastic member also has a function as an electrode terminal. Since it is not necessary to provide, it contributes to the reduction of the number of parts and the simplification of the manufacturing process, and the manufacturing cost can be suppressed. That is, according to the electricity storage device of the present invention, it is possible to contribute to cost reduction while satisfying the device reliability requirement.

It is sectional drawing which shows the structure of the electrical storage stack 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 perspective view which shows the external appearance of the battery cell which concerns on this invention. It is sectional drawing which shows the structure of the elastic conductive part with which a battery module is provided.

  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 a power storage stack 1 according to the present invention. The power storage stack 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 stack 1 includes a battery module 2 as a plurality of “power storage devices”, a plurality of attachments 3, an end plate 4, and a bus bar 5.

  As will be described in detail later, the battery module 2 accommodates the laminated structure 10 including a plurality of battery cells 10a to 10d and restricts displacement of the battery cells 10a to 10d 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 stack 1 to, for example, a mounted vehicle. Further, the end plate 4 is made of a conductive material such as Fe, Al, or Mg, and incorporates a conductive bus bar 5 via an insulating material such as plastic. The end plate 4 exposes the bus bar 5 only at the connection portion with the battery module 2. One end of the bus bar 5 is connected to, for example, a vehicle power control device (not shown), and transfers power between the power storage stack 1 and the vehicle power control device. In other portions, the battery module is adjacent to the end plate 4. The plurality of battery modules 2 are charged and discharged by being connected to the two electrode terminals. That is, the two bus bars 5 provided in the power storage stack 1 serve as a positive electrode and a negative electrode for charging and discharging the power storage stack 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.

  The battery module 2 includes a laminated structure 10, a housing 20, a pillar member 30, and an elastic conductive part 40.

  The stacked structure 10 includes a plurality of stacked battery cells 10a to 10d. Each of the battery cells 10a to 10d can be charged by storing a battery element made up of an electrode body 11 and an electrolyte 12 configured by laminating a positive electrode plate, a negative electrode plate, and a separator (not shown) inside the exterior body 15. It is.

  Each of the battery cells 10 a to 10 d transmits and receives electric power through the positive terminal 13 and the negative terminal 14 formed at the center of the front and back surfaces of the exterior body 15. In the present embodiment, the four battery cells 10a to 10d are stacked such that the positive electrode terminal 13 and the negative electrode terminal 14 of adjacent cells are in contact with each other, and are connected in series. Thereby, in this embodiment, in the battery module 2, the positive electrode terminal 13 of the battery cell 10a arrange | positioned at the uppermost part and the negative electrode terminal 14 of the battery cell 10d arrange | positioned at the lowest part are set as a "conductive part." The stacked structure 10 is exposed at both end surfaces in the stacking direction.

  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 battery module 2 according to the present invention, in the stacked battery cells 10a to 10d, the two battery cells 10a to 10d arranged adjacent to each other have the positive terminal 13 and the negative terminal 14 respectively. The battery cells 10a to 10d are connected at the center. Therefore, even if it is a case where thickness increases with expansion | swelling of each battery cell 10a-10d, the conduction | electrical_connection state of the two battery cells 10a-10d arrange | positioned adjacently can be maintained favorable. In addition, when connecting between each battery cell 10a-10d electrically, the positive electrode terminal 13 and the negative electrode terminal 14 are not an essential structure. The film thickness of the laminate film, which is the outer package 15 of the battery cells 10a to 10d, is generally several tens of μm, and even when stacked without the positive electrode terminal 13 and the negative electrode terminal 14, the battery cells 10a to 10d. The electrical connection between 10d is not disturbed. Therefore, sufficient electrical connection can be obtained (not shown) by laminating the exposed portions of the electrode bodies 11 of the battery cells 10a to 10d facing each other.

  The casing 20 is formed in a box shape by a rigid member, and fixes the laminated structure 10 to be accommodated, and protects the laminated structure 10 from an external impact or the like.

  The pillar member 30 is made of a resin material, and is provided through the first through holes 18 formed in the battery cells 10a to 10d, 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 the conductive portion is exposed in the first through hole 18 of each of the battery cells 10a to 10d, each of the battery cells 10a to 10d. Short circuit can be prevented. 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.

  As will be described in detail later, the elastic conductive portion 40 includes a member having elasticity and conductivity, and is formed as a conduction path for electrically conducting the inside and outside of the housing 20. More specifically, one end of the elastic conductive portion 40 disposed on the upper surface of the housing 20 is connected to the positive electrode terminal 13 of the battery cell 10 a disposed at the top in the housing 20. The other end protrudes outside the housing 20 through the second opening 21 formed on the upper surface. Further, one end of the elastic conductive portion 40 disposed on the lower surface of the housing 20 is connected to the negative electrode terminal 14 of the battery cell 10 d disposed at the lowermost portion inside the housing 20, and is formed on the lower surface of the housing 20. The other end protrudes outside the housing 20 through the second opening 21.

  Further, when the plurality of battery modules 2 are configured as a stack, the other end of the elastic conductive portion 40 is electrically connected to the opposing elastic conductive portion 40 or the bus bar inside the end plate 4 as shown in FIG. Thus, it is possible to exchange power with each other. Needless to say, the elastic conductive portion 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.

  Then, the structure of each battery cell 10a-10d is further demonstrated. In the present embodiment, since the battery cells 10a to 10d have the same configuration, the battery cell 10a will be described in detail here, and the detailed description of the other battery cells 10b to 10d will be omitted. FIG. 3 is a perspective view showing an appearance of the battery cell 10a according to the present invention.

  In the present embodiment, the battery cell 10a includes a battery element composed of the electrode body 11 and the electrolyte 12, 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 outer package 15 is formed by laminating an upper surface laminate film 16 constituting a first surface of the battery cell 10a and a lower surface laminate film 17 constituting a second surface facing the first surface. 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 top laminate film 16 has a first opening 19 that exposes the positive electrode terminal 13 of the battery cell 10a, and constitutes a conductive portion in a part of the covering region 16a. Here, an adhesive 50 may be applied around the first opening 19 exposing the positive electrode terminal 13 as necessary.

  The bottom laminate film 17 has the same configuration as the top laminate film 16 and has a first opening 19 (not shown) that exposes the negative electrode terminal 14 of the battery cell 10a. Configure. An adhesive 50 (not shown) may be applied around the opening that exposes the negative electrode terminal 14.

  Among the plurality of battery cells 10a to 10d to be stacked, two cells arranged adjacent to each other are in contact with the positive electrode terminal 13 of one cell and the negative electrode terminal 14 of the other cell. When 50 is applied, a good contact state can be maintained by the adhesive 50 applied to the periphery thereof.

  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 of the battery cells 10a to 10d in the present embodiment. Then, the column member 30 is passed through the first through holes 18 of the plurality of battery cells 10a to 10d to be stacked, and the column member 30 is fixed to the housing 20 as described above. The horizontal displacement of each of the battery cells 10a to 10d can be restricted.

  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 the battery cells 10 a to 10 d 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.

  Next, the configuration of the elastic conductive portion 40 according to the present invention will be described in more detail. FIG. 4 is a cross-sectional view illustrating a configuration of the elastic conductive portion 40 included in the battery module 2.

  The elastic conductive portion 40 includes an insulating member 41 and an elastic member 42. Here, as shown in FIG. 2, the upper surface and the lower surface of the housing 20 face the conductive portions of the stacked structure 10 (that is, the positive terminal 13 of the battery cell 10a and the negative terminal 14 of the battery cell 10d). A second opening 21 is formed at the position. And the elastic conductive part 40 is provided in the 2nd opening part 21 of the housing | casing 20, as shown in FIG.

  The insulating member 41 is made of a polymer material having electrical insulating properties such as a rubber material. Further, in this embodiment, the insulating member 41 is formed in an H-shaped cross-sectional shape, and an outwardly recessed portion is fitted and supported over the inner periphery of the second opening 21 of the housing 20. The

  The elastic member 42 is made of a member having elasticity and electric conductivity, and is formed as a metal leaf spring in the present embodiment. The elastic member 42 is supported by being fitted into an inwardly recessed portion of the insulating member 41, and is formed so that an elastic force acts on the inside and outside directions of the housing 20. And the elastic member 42 can charge / discharge each battery cell 10a-10d inside the battery module 2 by electrically conducting the inside and outside of the battery module 2. FIG. The elastic member 42 may be another member having elasticity and electrical conductivity. For example, the elastic member 42 may be a coiled wire spring or a combination of a leaf spring and a wire spring.

  Here, the elastic member 42 is configured to block the second opening 21 together with the insulating member 41, thereby preventing dust and moisture from entering the battery module 2 from the second opening 21. Moreover, the elastic member 42 forms the end part 42a of the housing | casing 20 in the inside / outside direction as a flat plate, and expands a contact area with the battery module 2 or bus bar 5 arrange | positioned adjacently as shown in FIG. Thus, the electrical conduction state can be stabilized, and further, heat generation at the contact portion can be suppressed.

  As described above, the elastic conductive portion 40 is displaced in the stacking direction by the elastic force of the elastic member 42 supported by the casing 20 of the battery module 2 via the insulating member 41. It is possible to improve the reliability of external vibration input. Further, the elastic conductive portion 40 is laminated so that the elastic member 42 absorbs the displacement in the thickness direction even when the plurality of laminated battery cells 10a to 10d expand and contract with charging / discharging. Since the structure 10 is supported, the reliability with respect to the vibration input can be further improved.

  Furthermore, the elastic conductive portion 40 charges and discharges the battery module 2 by electrically connecting the inside and outside of the housing 20 in addition to the elastic member 42 restricting the displacement of the laminated structure 10 as described above. It also functions as an electrode terminal. For this reason, since it is not necessary to provide electrode terminals, such as a contactor separately, the battery module 2 can also reduce manufacturing cost by simplifying manufacturing processes, such as welding, besides a number of parts. In addition, in the electrode terminal as a rigid body as in the prior art, there is a possibility that stress is concentrated on the connection portion of the electrode terminal due to expansion and contraction accompanying charging / discharging of the battery cells 10a to 10d, leading to problems. In the elastic conductive part 40 according to the present invention, the elastic member 42 absorbs the stress, thereby reducing the fear.

  In addition, since the insulating member 41 is made of, for example, a rubber material, the elastic conductive portion 40 has an influence on the elastic member 42 by absorbing the vibration as a cushioning material even if the casing 20 is subjected to vibration from the outside. Can be reduced, and the reliability with respect to vibration input can be further improved.

  As described above, the power storage device according to the present invention can provide a power storage device that can contribute to cost reduction while satisfying the reliability requirement of the device.

DESCRIPTION OF SYMBOLS 1 Power storage stack 2 Battery module 10 Laminated structure 10a-10d Battery cell 13 Positive electrode terminal 14 Negative electrode terminal 15 Exterior body 16 Upper surface laminate film 17 Lower surface laminate film 19 1st opening part 20 Housing | casing 21 2nd opening part 40 Elastic conductive part 41 Insulating member 42 Elastic member

Claims (1)

The exterior body contains a battery element, and is composed of a laminate film having a first surface and a second surface opposite to the first surface, and a conductive portion of the battery element is disposed on the exterior surface of the first surface. And a plurality of battery cells in which a first opening exposed in each of the second surfaces is stacked such that the conductive portions are in contact with each other, and the conductive portions are exposed at both end surfaces in the stacking direction. A structure,
A housing that houses a plurality of the battery cells;
A second opening provided in the housing to face the conductive portion of the multilayer structure;
An insulating member provided at the periphery of the second opening;
An elastic member electrically connected to the conductive portion and supported by the insulating member;
An electricity storage device comprising:

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