JP5490652B2 - Battery structure - Google Patents

Description

The present invention relates to a structure of an assembled battery in which a plurality of batteries are combined. In particular, the present invention relates to an assembled battery structure in which flat batteries are arranged in a stacked state at a predetermined interval.

In an electric vehicle, a hybrid vehicle, and the like, an assembled battery in which secondary batteries are assembled as a power source is used. In the process of charging or discharging, if the battery overheats or the temperature difference between the batteries increases, the performance of the battery may deteriorate or the battery may be damaged. Usually, these assembled batteries are stored in the battery case. Then, cooling air is sent into the battery case to cool the assembled battery.

The battery used for the assembled battery includes a substantially flat battery such as a lithium ion battery, and such a battery is sometimes called a square battery because of its shape.
When a flat battery is configured as an assembled battery, the flat batteries are separated from each other by a predetermined distance so that the wide surfaces of the batteries face each other so that the cooling air can be efficiently cooled. It is generally performed to arrange in a stacked state.

In cooling these assembled batteries, it is necessary to equalize the temperature of a plurality of batteries constituting the assembled battery as much as possible and cool the battery efficiently. For this purpose, various assembled battery structures and batteries are required. Cooling structures have been proposed.
For example, Patent Document 1 discloses an assembled battery cooling structure in which cooling air distributed between flat batteries arranged at a predetermined interval is guided to uniformly cool a plurality of batteries. ing. Patent Document 2 discloses an assembled battery structure in which an insulating separator is sandwiched between batteries, a cooling air passage (cooling gap) is formed by the uneven shape of the insulating separator, and insulation between the batteries is ensured. It is disclosed.

JP 2008-254627 A JP 2010-153141 A

In battery packs used in electric vehicles and the like, battery outer cans tend to be made thinner in order to reduce the system weight and save space. Here, when the battery outer can is made thinner with a flat battery such as a lithium ion battery, the tendency of the wide surface of the battery to be swollen by internal pressure becomes prominent due to changes in the temperature of the battery and the generation of gas inside. Cheap.

In the case of an assembled battery structure that does not have a member that restrains the expansion of the battery between the flat battery and the battery as in the assembled battery structure described in Patent Document 1, the wide surface of the battery expands. As a result, the gaps between the batteries become smaller and it becomes difficult for air to flow through the gaps, the air volume of the cooling air is reduced, the batteries cannot be uniformly cooled, and some batteries may be heated abnormally There is. Further, when the battery expands significantly, there is a risk that adjacent battery outer cans come into contact with each other and the insulation property is broken.

If it is an assembled battery structure of the type which sandwiches an uneven | corrugated plate-shaped insulation separator between batteries as described in patent document 2, the expansion | swelling of a battery is positively suppressed and the clearance gap between batteries is appropriate. However, such a battery assembly structure requires a large number of components to be manufactured and assembled with high accuracy, resulting in high manufacturing costs and manufacturing processes. It is complicated.

That is, an object of the present invention is to provide an assembled battery structure that can effectively suppress the expansion of the battery constituting the assembled battery and has few components.

As a result of intensive studies, the inventor of the present invention uses an interval holding member in which a plurality of bar-shaped spacers are connected in a comb shape so that the bar-shaped spacers are sandwiched between the batteries. In this case, it is found that the swelling of the flat battery is effectively suppressed by the rod-shaped spacer sandwiched between the batteries, and that a large number of spacers can be handled as an extremely small number of spacing members. Completed the invention.

The present invention provides an assembled battery structure in which a plurality of flat batteries are arranged in a stacked manner with a predetermined interval so that the wide surfaces thereof are opposed to each other. The pair of holder members provided hold the battery in a predetermined position, and a plurality of rod-shaped spacers corresponding to the space between the batteries are arranged in a row in the battery stacking direction in a comb shape. There is one interval holding member, and the rod-shaped spacer is sandwiched between the batteries, and a region of the wide surface of the battery that is not held by the holding portion is divided by the rod-shaped spacer. Thus, a battery pack structure in which the spacing members are arranged (first invention).

In the first invention , the rod-shaped spacers are arranged in at least two rows, and a plurality of rod-shaped spacers are sandwiched between the batteries, and the holding portion of the wide surface of the battery region which is not held Ru is approximately equally divided by the plurality of rod-like spacers. Moreover, in this invention, it is preferable that a holder member is made into plate shape and prevents the air leak from an assembled battery side part ( 2nd invention).

According to the present invention, the gap between the batteries is maintained by the interval holding member in which a plurality of bar-shaped spacers are arranged in a row in the battery stacking direction. There is no need to manufacture and assemble an insulating spacer, and the number of parts constituting the assembled battery structure can be greatly reduced. Moreover, since the area | region which is not hold | maintained by the said holding | maintenance part is divided | segmented by the rod-shaped spacer clamped between batteries, a small number of rod-shaped spacers are clamped between the batteries. With such a simple configuration, expansion deformation of the battery can be effectively suppressed.

Further, in the first invention, since a plurality of bar-shaped spacers are sandwiched between the batteries and the wide surface of the battery is equally divided by the bar-shaped spacers, the effect of suppressing the expansion and deformation of the battery can be suppressed particularly effectively. can get.

Further, in the present invention, when the holder member is formed in a plate shape to prevent air leakage from the side of the assembled battery as in the second invention, the holder member can also be used as a constituent member of the ventilation path. The battery cooling structure including the assembled battery structure can be configured with a smaller number of parts.

It is a perspective view which shows the assembled battery structure of embodiment of this invention. It is an exploded view which shows the structure of the assembled battery structure of embodiment of this invention. It is a perspective view which shows the space | interval holding member of embodiment of this invention. It is a perspective view which shows the holder member of embodiment of this invention. It is sectional drawing which shows arrangement | positioning of the rod-shaped spacer in embodiment of this invention. It is an exploded view which shows the structure of the assembled battery structure of 2nd Embodiment of this invention. It is sectional drawing which shows arrangement | positioning of the rod-shaped spacer in 2nd Embodiment of this invention. It is a perspective view which shows the other example of a space | interval holding member in this invention.

Hereinafter, an embodiment of an assembled battery structure of the present invention will be described with reference to the drawings, taking an assembled battery structure for a hybrid vehicle as an example. FIG. 1 is a perspective view of an embodiment of an assembled battery structure of the present invention. FIG. 2 is an exploded view showing the component structure of the assembled battery structure of the present embodiment. The white arrow in FIG. 2 indicates the direction of assembly of the component parts.

In the assembled battery structure 1, the flat batteries 2 and 2 constituting the assembled battery are arranged in a stacked state at a predetermined interval so that the wide surfaces of the batteries face each other. The batteries 2 and 2 are electrically connected in series or in parallel to form an assembled battery. In the present embodiment, the battery constituting the battery module is a lithium ion battery, and the battery 2 has a flat plate shape (flat rectangular parallelepiped shape). The batteries 2 and 2 are laminated so that the wide flat surfaces face each other, and terminals are provided on the side surfaces (surfaces adjacent to the wide flat surfaces) of the respective batteries.

In order for the batteries 2 and 2 to be positioned and held in a stacked state, a pair of holder members 3 and 3 are provided so as to face the side surfaces of the batteries 2 and 2. The holder member 3 is formed in a plate shape so as to cover the entire side surface portions at both ends of the batteries 2 and 2, and the holder members 3 and 3 are provided with holding portions 31 each having a shape for holding the both end portions 21 and 21 of the battery. , 31 are provided. FIG. 4 shows the shape of the holder member 3. In the present embodiment, the holding portion 31 is provided so as to protrude from the holder member main body in a shape that surrounds and fits the both end portions 21 of the battery. Further, the holder member 3 is provided with a through hole H through which a battery terminal portion and a fixing projection pass. The battery terminals exposed to the outside through the through holes of the holder member are connected to each other to function as an assembled battery. The holder member may have another shape as long as the position of the battery can be fixed appropriately. Further, the through hole H may be omitted if it is not necessary.

A pair of end plates 4, 4 are provided so as to face the wide surfaces of the batteries at both ends in the stacking direction of the assembled battery positioned in a stacked manner. A pair of holder members 3, 3 are attached to the end plates 4, 4 and are fixed by bolts, bands or the like, and serve to maintain the battery fixing structure. The end plates 4 and 4 can be omitted or simplified as long as the holder member is appropriately attached.

In the assembled battery structure of the present embodiment, the holder members 3 and 3 and the end plates 4 and 4 constitute a square tube-shaped ventilation path and constitute a part of the cooling air ventilation path. That is, a blower fan and other passage members (ducts and the like) are provided on the upstream side and the downstream side of the assembled battery structure to constitute a battery cooling system as a whole. The batteries 2 and 2 arranged in a stacked manner are placed in this rectangular tube-shaped ventilation path and cooled by cooling air flowing through the inside of the passage. Therefore, it is preferable that the holder member 3 and the end plate 4 have a shape that forms an opening that can be easily fitted into a duct or the like in an assembled state. Further, it is preferable to provide a seal member or the like at a portion where the holder member 3 or the end plate 4 is connected to a duct or the like.
When the cooling air passage is formed separately from the assembled battery structure by a battery case that houses the assembled battery structure 1 or the like, it is necessary to form a rectangular tube-shaped ventilation path by the holder member or the end plate. Absent.

A single plate-like spacing member 5 is disposed at a position that is substantially the center of the pair of holder members 3 and 3. As shown in FIG. 3, the spacing member 5 is provided with a plurality of bar-shaped spacers 51, 51 that should extend in parallel with the holder member or the flat battery, and are arranged in a comb shape in parallel with each other. One end is integrated by a rod-like connecting portion 52 to form a single plate. That is, in the present embodiment, the bar-shaped spacers 51 and 51 are arranged in a straight line. In the assembled state of the assembled battery, the respective rod-like spacers 51 and 51 are arranged so as to correspond to the space between the batteries 2 and 2 arranged at a predetermined interval from each other, and the batteries 2 and 2 face each other. It is sandwiched between wide surfaces. Moreover, you may fix the space | interval holding member 5 to the end plate 4 by bolting or fitting the both ends of the connection part 52 as needed.

FIG. 5 is a cross-sectional view of the gaps between the stacked batteries 2 and 2 as viewed along the battery stacking direction. Both end portions 21, 21 of the battery 2 are held by holding portions 31, 31 of the holder member 3, and a rod-like spacer 51 is arranged so as to cross a substantially central portion of the wide surface of the battery 2. That is, on the wide surface (flat area) of the flat battery 2, the flat area S (area surrounded by a dotted line in the figure) that is not held by the holding portion is divided into two equal parts by the rod-shaped spacer 51. It is divided into In FIG. 5, the cooling air is configured to flow from the upper side to the lower side of the drawing, and the bar spacers are arranged along the flow direction so as not to disturb the flow of the cooling air.

The assembled battery structure can be configured by a known manufacturing method. For example, the holder member 3, the end plate 4, and the spacing member 5 can be manufactured by, for example, synthetic resin injection molding, and can be coupled to each other via a fastening member such as a bolt or a clip to constitute the assembled battery structure. . These members can be made of metal members according to requirements such as strength and thermal requirements. When these members have portions that require sealing properties and elasticity, it is preferable that the portions be made of an elastic material such as rubber or elastomer.

In assembling the assembled battery structure, the spacing member 5 can be attached at an appropriate time. For example, in parallel with the process of holding the batteries 2 and 2 on the holder member 3, the rod-shaped spacer 51 of the interval holding member 5 may be held between the batteries. Alternatively, after the batteries 2 and 2 are aligned and arranged by the holder members 3 and 3, the spacing member 5 is parallel to the holder member 3 so that the rod-like spacers 51 and 51 enter the gap between the batteries. The spacing member 5 may be pushed in.

The operation and effect of the assembled battery structure of the present invention will be described.
In the assembled battery structure of the present invention, a large number of insulating separators as in the technique described in Patent Document 2 are not necessary, and a very small number of (one in the first embodiment) spacing member 5 is used. The rod-shaped spacers 51 and 51 can be disposed between the batteries. That is, the number of parts constituting the assembled battery structure can be greatly reduced.

Further, according to the assembled battery structure of the present invention, the arrangement and fixation of the large number of bar-shaped spacers 51 and 51 can be performed by arrangement and fixation as a very small number (one in the above embodiment) of the spacing members 5. As a result, the assembly process of the assembled battery structure is greatly simplified.

And according to the assembled battery structure of this invention, expansion | swelling of a battery is suppressed effectively by the rod-shaped spacers 51 and 51 clamped between the batteries 2 and 2. FIG. In the present invention, both end portions of the batteries 2 and 2 are held by the holding portions 31 of the holder member 3, and the area S that is not held by the holding portion 31 on the wide surface of the battery (enclosed by a dotted line in FIG. 5). The bar-shaped spacers are sandwiched so that the region shown) is divided by the bar-shaped spacers 51.

In the part where the bar-shaped spacer 51 is in direct contact with the battery 2, the expansion deformation of the battery outer can is directly suppressed by the bar-shaped spacer being sandwiched between the batteries. The region where expansion deformation is not directly suppressed by the rod-shaped spacer or the holding portion has room for expansion deformation, but the region S not held by the holding portion 31 on the wide surface of the battery is divided by the rod-shaped spacer 51. Therefore, the size of the region where the deformation is allowed is reduced, and the expansion deformation can be significantly suppressed.

According to the inventors' investigation of structural analysis simulation, an internal pressure of about 1 MPa was applied to a battery outer can made of aluminum having a thickness of 0.5 mm with a flat battery having a size of 120 mm × 80 mm and a thickness of 20 mm. The expansion deformation was 2.2 mm when there was no rod-shaped spacer, whereas when one rod-shaped spacer was provided in the center, the expansion deformation was 0.17 mm. It was confirmed that the expansion deformation of the battery outer can can be significantly suppressed.

That is, according to the assembled battery structure of the present invention, since the region S that is not held by the holding portion 31 on the wide surface of the battery is divided by the bar-shaped spacer, a simple configuration in which a small number of bar-shaped spacers are sandwiched. Thus, a significant effect of suppressing expansion and deformation is obtained.

In order to exhibit this expansion deformation suppressing effect more effectively, it is very effective to reduce the width W of the region after the region S is divided. From this point of view, the rod-shaped spacers are arranged so as to equally divide the region S, that is, one spacing member 5 is located at the center of the pair of holder members 3 so that a large divided region does not occur. It is preferable to do so.

In the above embodiment, one bar-shaped spacer is sandwiched between the batteries. More preferably, two or more bar-shaped spacers are arranged between the batteries, and these spacers are used. If the region S is divided (particularly preferably equally divided), the width of the divided region is reduced, and the expansion deformation of the battery outer can is particularly effectively suppressed.

In the above embodiment, the holder members 3 and 3 and the end plates 4 and 4 form a rectangular tube-shaped ventilation path. If it is made to cover and air leakage from the side of the assembled battery is prevented, a ventilation path capable of effectively preventing leakage of cooling air flowing through the gap between the batteries is provided with the holder member 3, which is a structural member. 3 can be realized, and an assembled battery structure and a battery cooling structure can be configured with a particularly simple configuration.

The present invention is not limited to the above embodiment, and can be implemented with various modifications. Although other embodiments of the present invention will be described below, in the following description, portions different from the above embodiment will be mainly described, and the description of the same portions will be simplified or omitted.

First, an example of changing the spacing member will be described. There are no particular limitations on the spacing member in which rod-shaped spacers sandwiched between the batteries are arranged as long as a plurality of rod-shaped spacers can be efficiently arranged. It is preferable that they are arranged side by side in a straight line. The form of the continuous arrangement of the rod-shaped spacers is not limited to a straight line, and may be, for example, a zigzag-shaped continuous arrangement. This is particularly preferable from the viewpoint of preventing deformation of the battery outer can because the battery is sandwiched in the battery stacking direction and there is no fear that a bending deformation input is applied to the battery.

Further, the spacing member 7 may be a spacing member 7 in which rod-like spacers 71 and 71 are arranged in a straight line in two rows as in the second embodiment shown in FIG. In this case, two bar-shaped spacers are arranged between the batteries. As shown in FIG. 7, the rod-shaped spacers 71 and 71 are arranged so that the flat plate-like region S that is not held by the holding portion 31 on the wide surface of the battery is equally divided into three strips. Is particularly preferred.

Also in the present embodiment, the blistering of the battery outer can can be effectively suppressed with a simple component configuration.

The form in which the rod-shaped spacers are continuously provided in the battery stacking direction may be one row, two rows, or more. These rod-shaped spacers may all be integrated into one interval holding member as in the second embodiment, or one interval holding as in the first embodiment for each columnar spacer forming each row. A member may be configured, and one or a plurality of spacing members may be provided in the assembled battery structure. In addition, the spacing member can be appropriately divided in the battery stacking direction (for example, divided into two or three).

Various modifications can be made to the form of the spacing member. As shown in FIG. 8A, the spacing member 8 can also be configured by connecting and integrating both ends of the rod-shaped spacers 81, 81 connected to each other by connecting portions 82, 82. In this case, the assembled battery may be assembled by passing the battery 2 between the rod-shaped spacers 81 and 81. Further, as shown in FIG. 8B, one connecting portion 92 of the connecting portions connecting and integrating the end portions of the rod-shaped spacers 91 and 91 is formed integrally with the rod-shaped spacers 91 and 91, and the other connecting portion. 93 may be configured to be assembled / removable with a bar-shaped spacer. If it does in this way, the freedom degree of the assembly process of an assembled battery can be raised, ensuring arrangement | positioning and fixation of a rod-shaped spacer.

Moreover, it can also be set as the space | interval holding member 10 like FIG.8 (c), In this form, the rod-shaped spacers 101 and 101 provided in a row are connected alternately by the connection parts 102 and 102 with short ends. Thus, as a whole, a single wire is formed into a plate shape that is bent into a bow shape. The spacing member of this embodiment can be manufactured by bending a wire that has been extruded into a predetermined dimension, for example.

In addition, when a flow control plate (such as a plate provided with a slit corresponding to the gap between the batteries) is provided on the upstream side or downstream side of the assembled battery to adjust the flow of cooling air In addition, it is also a preferred embodiment that the interval holding member is configured using a flow control plate as a connecting portion for connecting and integrating the rod-shaped spacers.

In addition, in the said embodiment, although the holder member 3 and the end plate 4 were comprised with the plate-shaped member, and embodiment was used as a square tube-shaped ventilation path, it does not necessarily need to be a plate-shaped member. As long as the structure of the assembled battery can be appropriately maintained, it may be constituted by a rod-like member, a block-like member, a band member, or the like. In that case, another member (for example, a battery case) may vent the cooling air. A route may be configured. Moreover, these members can also be divided | segmented suitably and comprised.

Examples of the type of flat battery constituting the assembled battery include primary batteries, secondary batteries (lithium ion batteries, nickel metal hydride batteries, nickel cadmium batteries, etc.), double electric capacitors, and the like. Examples of the battery are modularized. In the above-described embodiment, the battery has been described as having a flat plate shape, but the battery may have a flat plate shape with some bends. Further, the surface of the flat battery does not need to be flat, and may be a battery having uneven strips for improving the cooling performance and improving the rigidity of the battery outer can.

The purpose and application for which the assembled battery is used are not limited to those for automobiles. For example, a secondary battery is used for the purpose of leveling generated power in a wind power generator or a solar battery power generator. The present invention can be applied to the configuration of an assembled battery used for a wide range of applications.

INDUSTRIAL APPLICABILITY The present invention can be used for the construction of large capacity assembled batteries used in electric vehicles, hybrid vehicles, power generators, etc., and the flat batteries constituting these assembled batteries are arranged and arranged with few parts, and the batteries are swollen. Deformation can be suppressed and the industrial utility value is high.

DESCRIPTION OF SYMBOLS 1 assembled battery structure 2 battery 3 holder member 31 holding | maintenance part 4 end plate 5 space | interval holding member 51 rod-shaped spacer 52 connection part 7, 8, 9, 10 space | interval holding member

Claims (2)

A plurality of flat batteries are assembled battery structures arranged in a stacked manner with a predetermined interval so that their wide surfaces face each other,
While holding the battery in a predetermined position by a pair of holder members provided with holding parts capable of holding both ends of the battery,
A plurality of bar-shaped spacers corresponding to the space between the batteries, and having at least one spacing member arranged in a comb-like manner along the battery stacking direction;
The rod-shaped spacer is sandwiched between the batteries, respectively,
The space holding member is disposed so that a region of the wide surface of the battery that is not held by the holding portion is divided by the rod-shaped spacer , and
The rod-shaped spacers are arranged in at least two rows, a plurality of rod-shaped spacers are sandwiched between the respective batteries, and the plurality of regions that are not held by the holding portion on the wide surface of the battery An assembled battery structure divided approximately by a bar-shaped spacer . The assembled battery structure according to claim 1 , wherein the holder member has a plate shape to prevent air leakage from the side of the assembled battery.

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