JP2008235149A - Spacer member for battery pack and battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a temperature of the whole battery pack from rising, and to suppress the deterioration of a cyclic life caused by the deformation of respective flat cells in the case that the battery pack in which a plurality of the flat cells are laminated is charged and discharged wherein spacer members for the battery pack are arranged between the flat cells of which both surfaces are flat. <P>SOLUTION: In the battery pack wherein the plurality of flat cells 20 of which both surfaces are flat are laminated, the spacer members 10 for the battery pack having flat surfaces on both sides for contacting with respective flat cells and having a space part 14 for ventilation in it are sandwiched between the respective flat cells. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an assembled battery spacer member disposed between flat battery cells with both surfaces flat and an assembled battery in which a plurality of flat battery cells with both surfaces flattened, and in particular, the above assembled battery. When charging / discharging, the heat generated in each flat battery can be appropriately dissipated to the outside, and each flat battery is deformed when this assembled battery is pressurized with a pressure holder. It is characterized in that the pressure is appropriately applied.

  Conventionally, a flat battery in which a plurality of electrode bodies in which a plurality of positive electrodes and negative electrodes are laminated via a separator is housed in an outer package and both surfaces are flattened has been used in various fields. In order to use a flat plate battery for a robot, an electric vehicle, a backup power source, or the like, it is used as an assembled battery in which a plurality of flat plate batteries are stacked.

  Here, when charging and discharging an assembled battery as described above, each flat battery expands and contracts due to charging and discharging and deforms, and the cycle life is greatly deteriorated. Therefore, the assembled battery is pressurized so as to be sandwiched between the pressure holders.

  However, when charging and discharging the battery pack in such a manner that the battery pack is sandwiched between the pressure holders, when the battery pack is charged and discharged in a state in which the above flat batteries are directly stacked, If the heat generated in the battery is not properly dissipated to the outside, the temperature of the entire assembled battery rises, and if it is charged and discharged with a large current when used as a power source as described above, the temperature of the entire assembled battery In particular, when a high-capacity lithium secondary battery is used for the flat plate battery, the expansion and contraction of the battery due to charge / discharge is large, and the heat generation is large. Such a problem was a big problem.

  For this reason, in recent years, as shown in Patent Document 1, an assembled battery spacer member is disposed between the flat battery layers stacked as described above, and the assembled battery spacer member is in contact with the flat battery element. The surface to be corrugated is provided with irregularities such as a wave shape or a rectangular shape, and a space for ventilation is formed between the spacer member for the assembled battery and the flat plate battery, and the heat generated in each flat plate battery through this space portion is generated. It has been proposed to dissipate heat to the outside.

However, an assembled battery spacer member having a corrugated shape such as a wave shape or a rectangular shape on the surface in contact with the flat battery is arranged between the flat batteries, and the assembled battery is held in the pressure holder as described above. When the pressure is applied so as to sandwich the battery, the pressure acting on the flat battery becomes non-uniform by the assembled battery spacer member. There is a problem that the flat battery is greatly deformed and the cycle life is greatly deteriorated.
Japanese Patent Laid-Open No. 10-112301

  An object of the present invention is to solve the above-described various problems in the case where a plurality of flat batteries whose surfaces are flat are stacked and used as an assembled battery.

  That is, in the present invention, in the above assembled battery, when the assembled battery spacer member arranged between the flat batteries is improved and the above assembled battery is charged / discharged, it occurs in each flat battery. The heat generated is appropriately dissipated to the outside to prevent the temperature of the entire assembled battery from rising, and when this assembled battery is pressurized by the pressure holder, each flat battery is properly deformed. It is an object of the present invention to prevent the cycle life from being deteriorated by being pressurized to a constant pressure.

  In the present invention, in order to solve the above-described problems, in the assembled battery spacer member disposed between the flat batteries whose both surfaces are flat, both surfaces contacting each flat battery are made flat. At the same time, a space for ventilation is formed inside.

  Here, in the above-described assembled battery spacer member, both sides contacting each flat battery are made flat, and a spacer is provided between the two flat members in order to form a space for ventilation inside. In this case, at least one flat plate member may be provided with a spacer, and the flat plate members may be joined to each other via the spacer.

  In the assembled battery spacer member, the flat battery can be positioned by providing a locking projection for positioning the flat battery on the surface in contact with the flat battery.

  And in the assembled battery of this invention, when laminating | stacking two or more flat batteries in which both surfaces became flat, the above assembled battery spacer members were arrange | positioned between said flat batteries.

  Moreover, in this assembled battery, in order to prevent each flat battery from being deformed when the assembled battery is charged / discharged as described above, the assembled battery is inserted by pressure holders from both sides in the stacking direction of the flat battery. It is preferable to apply pressure so as to be sandwiched.

  In the assembled battery spacer member according to the present invention, since both sides contacting the flat battery are made flat and a ventilation space is formed inside, the assembled battery in which a plurality of flat batteries are stacked. When the assembled battery spacer member is disposed between the flat batteries, even if each of the flat batteries generates heat when the assembled battery is charged and discharged, the heat of each flat battery is reduced. Heat is appropriately radiated to the outside through the ventilation space of the assembled battery spacer member disposed between them, and the temperature of the entire assembled battery is prevented from rising.

  Further, when the assembled battery is pressed by the pressure holder so as to be sandwiched from both sides of the flat battery in the stacking direction, each flat battery is in contact with the flat surface of the assembled battery spacer member. Therefore, each flat battery comes to be uniformly pressed by the assembled battery spacer member, and even when this assembled battery is charged and discharged, the deformation of each flat battery is appropriately suppressed, The cycle life is prevented from deteriorating.

  As a result, when the assembled battery is manufactured by arranging the above-mentioned assembled battery spacer members between the flat batteries, a high-capacity lithium secondary battery is used for the flat battery, and the assembled battery is assembled with a large current. Even when the battery is charged / discharged, the temperature of the assembled battery as a whole is appropriately prevented from rising, and each flat battery is also appropriately prevented from being deformed, thereby improving the cycle life.

  Further, in the above-mentioned assembled battery spacer member, both surfaces contacting each flat battery are made flat, and a spacer is provided between the two flat plate members when forming a space for ventilation inside. Then, manufacture of the assembled battery spacer member is simplified, and by appropriately setting the number, size, and arrangement of the spacers, a space for ventilation is appropriately formed inside the assembled battery spacer member. The heat of each flat battery during charge / discharge can be more appropriately dissipated to the outside through the ventilation space, and the temperature of the entire assembled battery can be further prevented from rising. .

  Next, an assembled battery spacer member and an assembled battery according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. Note that the assembled battery spacer member and assembled battery according to the present invention are not particularly limited to those shown in the following embodiments, and can be implemented with appropriate modifications within the scope not changing the gist thereof.

  In this embodiment, as shown in FIGS. 1 (A) and 1 (B), a flat plate having both surfaces flattened on one surface of a rectangular flat plate member 11 as shown in FIGS. As the locking projections 12 for positioning and holding the battery 20, a pair of L-shaped first locking projections 12 a are provided at two corners on the short side of the flat plate member 11 so as to face each other. The second locking projections 12b are provided along the long sides on both sides so as to be spaced from the locking projections 12a. On the other hand, on the surface of the flat plate member 11 on the side opposite to the surface on which the locking projections 12 are provided, a plurality (9 in the example shown in the figure) spacers 13 are provided with a long side and a short side. It arrange | positions through a required space | interval in a side direction. The planar shape, number, and size of the spacers 13 provided on the flat plate member 11 are not particularly limited. For example, it is possible to provide an appropriate number of spacers having a circular shape, a rectangular shape, or the like.

  In this assembled battery spacer member 10, as shown in FIG. 2, the two flat plate members 11 provided with the locking projections 12 and the spacers 13 as described above are used, and the spacers in each flat plate member 11 are used. 13 are joined together to form a space portion 14 for ventilation inside the assembled battery spacer member 10, and the locking projections 12 provided on each flat plate member 11 include the above-described engaging projections 12 of the assembled battery spacer member 10. It is located on both sides. The material used for the assembled battery spacer member 10 is not particularly limited, but it is preferable to use a material having sufficient strength and excellent thermal conductivity. For example, a metal such as aluminum or a thermal conductivity is preferable. It is preferable to use an improved flame retardant resin.

  Next, an assembled battery in which a plurality of planar batteries 20 having both surfaces flattened using such an assembled battery spacer member 10 will be described.

  Here, as shown in FIGS. 3 to 5, the flat battery 20 having both surfaces flat as described above includes a positive electrode 21 provided with a positive electrode current collecting tab 21 a and a negative electrode provided with a negative electrode current collecting tab 22 a. The electrode body 24 in which a required number of positive electrodes 21 and negative electrodes 22 are laminated so that the separator 23 is interposed between the positive electrode current collecting tab 21a and the negative electrode current collecting tab 22a is a laminate film. The electrode body 24 is accommodated in the exterior body 25 so as to protrude outside from the configured exterior body 25, and the exterior body 11 is injected with an electrolyte solution. The one with the opening portion sealed was used.

  Then, as shown in FIG. 6, the flat battery 20 is positioned by the locking protrusions 12 provided on the assembled battery spacer member 10, and the flat battery 20 is placed on the assembled battery spacer member 10. Try to keep it on a flat surface.

  Then, the flat battery 20 is positioned by the locking projection 12 in this way, and the flat battery 20 is held on the flat surfaces on both sides of the assembled battery spacer member 10, respectively, as shown in FIG. The assembled battery spacer member 10 is sandwiched between the flat battery cells 20 so that a plurality of (five in the example shown in the figure) flat battery cells 20 are laminated to produce an assembled battery. The assembled battery is pressurized by the pressure holder 30 so as to be sandwiched from both sides in the stacking direction of the battery 20.

  Here, when the assembled battery is pressurized by the pressure holder 30 as described above so as to be sandwiched from both sides of the flat battery 20 in the stacking direction, in this embodiment, the pressure plates 31 are provided on both sides of the assembled battery in the stacking direction. And a plurality of fastening bolts 32 are inserted from the outer surface side of one pressure plate 31, and the tip of each fastening bolt 32 is caused to protrude through the other pressure plate 31. Further, a nut 33 is fastened to the tip of each fastening bolt 32, and the assembled battery is pressed between the pair of pressure plates 31 from both sides of the flat battery 20 in the stacking direction.

  When the assembled battery is pressed from both sides in the stacking direction by the pressure holder 30 in this way, the flat surface of each flat battery 20 in the assembled battery is made uniform by the pressure plate 31 and the assembled battery spacer member 10. Will be pressurized.

  And when an assembled battery is charged / discharged in this state, even if each flat battery 20 generates heat by charge / discharge, the heat of each flat battery 20 is arranged between the flat batteries 20. As a result, heat is appropriately radiated to the outside through the ventilation space 14 in the spacer member 10, so that the temperature of each flat battery 20 is prevented from rising, and the temperature of the entire assembled battery is prevented from greatly increasing. become.

  In this embodiment, since the flat surface of each flat battery 20 in the assembled battery is uniformly pressed by the pressure plate 31 and the assembled battery spacer member 10 as described above, When the assembled battery is charged and discharged as described above, the flat battery 20 is prevented from being deformed, and the cycle life is also prevented from being deteriorated.

  In the above-described embodiment, when the assembled battery spacer member 10 is manufactured, the two flat plate members 11 provided with the locking projections 12 on one side and the spacers 13 on the opposite side are used. Spacers 14 for ventilation are formed inside the assembled battery spacer member 10 by joining the spacers 13 in the flat plate members 11, and the locking projections 12 are positioned on both surfaces of the assembled battery spacer member 10. However, the assembled battery spacer member 10 is not limited to such a structure, and both surfaces contacting the flat battery 20 are flat, and a space portion 14 for ventilation is formed inside. That can be anything.

  For example, as shown in FIG. 8, a flat plate member 11A provided with a locking projection 12 on one side and a spacer 13 on the opposite side, and a locking member 12 provided on one side is provided on the opposite side. Using a flat plate member 11B having no spacer on the surface, as shown in FIG. 9, the spacer 13 provided on the flat plate member 11A is joined to the surface of the flat plate member 11B having no spacer. It is also possible to form a space portion 14 for ventilation inside, and although not shown in the drawing, a spacer is not provided on the two flat plate members, and a spacer is provided between the two flat plate members. It is also possible to arrange them.

  In addition, as an assembled battery spacer member 10 without using two flat plate members, for example, as shown in FIGS. It is also possible to form a ventilation space 14 penetrating in the direction (or longitudinal direction).

  In the above embodiment, as the flat battery 20, the electrode body 24 in which the required number of the positive electrodes 21 and the negative electrodes 22 are laminated with the separator 23 interposed between the positive electrode 21 and the negative electrode 22 is a laminate film. Although what was accommodated in the comprised exterior body 25 was used, the flat battery to be used is not limited to such a thing, What is necessary is just to be flat on both surfaces. For example, it is also possible to use a flat battery or the like in which a separator is interposed between a positive electrode and a negative electrode, and these are flatly wound and further pressed into a flat electrode body accommodated in an exterior body. It is.

It is the schematic plan view and schematic back view of the flat plate member used for producing the spacer member for assembled batteries used in embodiment of this invention. It is a schematic side view of said assembled battery spacer member. It is the schematic explanatory drawing which showed the state which produces the electrode body which laminated | stacked two or more these by interposing the separator between the positive electrode and the negative electrode in the flat battery used in embodiment of this invention. It is a schematic side view of said flat battery. It is a schematic plan view of said flat battery. It is the schematic plan view which showed the state which positioned the said flat battery by the latching protrusion provided in the spacer member for assembled batteries, and was hold | maintained on the flat surface of the spacer member for assembled batteries. A state in which an assembled battery in which a plurality of flat batteries are stacked with a battery pack spacer member interposed between the above flat batteries is pressed by a pressure holder so as to be sandwiched from both sides of the flat battery in the stacking direction. It is the shown schematic side view. It is the schematic plan view which showed the two flat plate members used for the 1st modification of the spacer member for assembled batteries used in embodiment of this invention. It is a schematic side view of the assembled battery spacer member according to the first modified example. It is the schematic side view and schematic plan view of the 2nd modification of the spacer member for assembled batteries used in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Assembly battery spacer member 11,11A-11C Flat plate member 12 Locking protrusion 12a 1st locking protrusion 12b 2nd locking protrusion 13 Spacer 14 Space for ventilation 20 Flat battery 21 Positive electrode 21a Positive electrode current collection tab 22 Negative electrode 22a Negative electrode current collecting tab 23 Separator 24 Electrode body 25 Exterior body 30 Pressure holder 31 Pressure plate 32 Fastening bolt 33 Nut

Claims (7)

  In the assembled battery spacer member disposed between the flat batteries whose both surfaces are flat, both surfaces contacting the flat batteries are flat and a space for ventilation is formed inside. An assembled battery spacer member.   The assembled battery spacer member according to claim 1, wherein a spacer is provided between two flat plate members to form the ventilation space.   The assembled battery spacer member according to claim 2, wherein a spacer is provided on the at least one flat plate member, and the flat plate members are joined to each other through the spacer.   The spacer member for an assembled battery according to any one of claims 1 to 3, wherein a locking protrusion for positioning the flat battery is provided on a surface in contact with the flat battery. An assembled battery spacer member.   In the assembled battery which laminated | stacked the flat battery in which both surfaces became flat, the spacer member for assembled batteries of any one of Claims 1-4 is arrange | positioned between said flat battery. A battery pack characterized by that.   6. The assembled battery according to claim 5, wherein the assembled battery is pressurized so as to be sandwiched by pressure holders from both sides of the planar battery in the stacking direction.   The assembled battery according to claim 5 or 6, wherein the flat battery is a lithium secondary battery.

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