JP2018081886A - Assembled battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assembled battery in which a short circuit between individual cells due to dust is suppressed. SOLUTION: The assembled battery includes a plate-shaped spacer 30 arranged in a gap between the arrayed cells, an upper end opening 32 opened at an upper end of the spacer 30, and a lower end opening 34 opened at a lower end of the spacer 30. , A communication path 36 that connects the upper end opening 32 and the lower end opening 34. In the width direction W orthogonal to the cell array direction and the cell height direction H, the opening width w1 of the upper end opening 32 is larger than the opening width w2 of the lower end opening 34, and the communication path 36 is the communication path. It has an inclined surface 38 that is inclined so that the width of the width 36 in the width direction W widens toward the upper end opening 32 and narrows toward the lower end opening 34. [Selection diagram] Fig. 4

Description

  The present invention relates to an assembled battery in which a plurality of chargeable / dischargeable cells are arranged in a predetermined direction.

  Lithium ion secondary batteries, nickel hydride batteries and other secondary batteries that are lightweight and provide high energy density are used as unit cells, and a battery pack that consists of a plurality of unit cells connected in series provides high output. As a power source to be used, it is preferably used as a vehicle-mounted power source or a personal computer and a portable terminal. For example, Patent Document 1 as an example of an assembled battery for a vehicle is configured by arranging a plurality of rectangular unit cells and connecting a positive electrode terminal and a negative electrode terminal provided on the upper surface of each unit cell in series. An assembled battery is disclosed.

JP 2006-091665 A

In an assembled battery in which a plurality of unit cells are arranged in a predetermined direction, as shown in FIG. 9, when dust 1 containing metal powder mixed from the outside of the assembled battery accumulates on the upper surface of the unit cell 2. There can be. When the dust 1 accumulates on the upper surface of the unit cell 2, there is a possibility that the unit cell 2 (for example, a battery case) may be short-circuited by bridging the adjacent unit cells 2 with the dust 1.
This invention is made | formed in view of this situation, The main objective is to provide the assembled battery which can suppress the short circuit between the single cells resulting from the said dust.

  The assembled battery provided by the present invention is an assembled battery in which a plurality of chargeable / dischargeable cells are arranged in a predetermined direction. The assembled battery includes a plate-like spacer disposed in a gap between the arranged single cells, an upper end opening opened at the upper end of the spacer, a lower end opening opened at the lower end of the spacer, and the upper end opening. A communication path communicating with the lower end opening. In the width direction perpendicular to the arrangement direction of the unit cells and the height direction of the unit cells, the opening width of the upper end opening is larger than the opening width of the lower end opening and the same width as the entire width of the spacer. Is formed. The communication path has an inclined surface that is inclined so that a width of the communication path in the width direction is widened toward the upper end opening and is narrowed toward the lower end opening. According to such a configuration, it is possible to provide a highly reliable assembled battery that can suppress a short circuit between the single cells due to dust accumulated on the upper surface of the single cells.

  In this specification, the “unit cell” is a term indicating individual storage elements that can be connected in series to form an assembled battery, and includes batteries and capacitors having various compositions unless otherwise specified. . The “secondary battery” generally refers to a battery that can be repeatedly charged, and includes so-called storage batteries such as lithium ion secondary batteries and nickel metal hydride batteries. The electric storage element constituting the lithium ion secondary battery is a typical example included in the “unit cell” referred to herein, and a lithium ion secondary battery pack including a plurality of such unit cells is disclosed herein. This is a typical example of an “assembled battery”.

It is a side view which shows typically the structure of the assembled battery which concerns on one Embodiment. It is a top view which shows typically the structure of the assembled battery which concerns on one Embodiment. It is a top view which shows typically the structure of the spacer which concerns on one Embodiment. It is a front view which shows typically the structure of the spacer which concerns on one Embodiment. It is a side view which shows typically the structure of the spacer which concerns on one Embodiment. It is AA sectional drawing of FIG. It is a side view which shows typically the structure of the assembled battery which concerns on one Embodiment. It is a front view which shows typically the structure of the spacer which concerns on one Embodiment. It is a side view which shows typically the structure of the conventional assembled battery.

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field. In addition, each drawing is drawn typically and does not necessarily reflect a real thing. Each drawing shows only an example, and each drawing does not limit the present invention unless otherwise specified.

  The assembled battery disclosed herein may be an assembled battery formed by arranging single cells (typically, single cells having a flat outer shape), and the configuration of the single cells is not particularly limited. Although not intended to be particularly limited, the present invention will be described in detail below using an example of an assembled battery in which a flat lithium ion secondary battery is a single battery and a plurality of the single batteries are connected in series. Explained.

<First Embodiment>
The structure of the assembled battery 10 of this embodiment is demonstrated referring FIG. 1 and FIG. FIG. 1 and FIG. 2 are diagrams schematically showing the configuration of the assembled battery 10 of the present embodiment, FIG. 1 is a side view, and FIG. 2 is a top view.

  The assembled battery 10 is configured by connecting a plurality of chargeable / dischargeable cells 20 in series. In the illustrated example, four unit cells 20 having the same shape are arranged in series at regular intervals. In addition, the code | symbol L in drawing shows the arrangement direction of a single cell (thickness direction of a single cell), the code | symbol H shows the height direction of a single cell, and the code | symbol W is the width direction (single cell arrangement direction with a single cell). The direction perpendicular to the height direction of the unit cell) is shown.

  The unit cell 20 includes an electrode body (not shown) including a positive electrode and a negative electrode, and a battery case 50 that houses the electrode body and an electrolyte. The electrode body of the present embodiment is composed of predetermined battery constituent materials (active materials for positive and negative electrodes, current collectors for positive and negative electrodes, separators, etc.) as well as single cells equipped in typical assembled batteries. Yes. Here, a flat wound electrode body is used as the electrode body.

  The battery case 50 of the present embodiment has a shape (box shape in the illustrated example) that can accommodate a flat wound electrode body. The material of the battery case 50 is not particularly limited as long as it is the same as that used for a typical unit cell, but from the viewpoint of reducing the weight of the assembled battery itself, for example, it is made of a thin metal or a synthetic resin. A container battery case may be used.

  On the upper surface of the battery case 50, a positive electrode terminal 60 electrically connected to the positive electrode of the wound electrode body and a negative electrode terminal 62 electrically connected to the negative electrode are provided. And between the adjacent unit cells 20, one positive electrode terminal 60 and the other negative electrode terminal 62 are electrically connected by an inter-terminal connector. Thus, the assembled battery 10 of the desired voltage is constructed | assembled by connecting each cell 20 in series.

  The unit cells 20 of the present embodiment are arranged in a predetermined direction. Specifically, the plurality of single cells 20 are arranged so as to be inverted one by one so that the positive terminals 60 and the negative terminals 62 are alternately arranged, and the side walls of the battery case 50 (of the battery case 50). A wide surface, that is, a surface corresponding to a flat surface of a wound electrode body (described later) housed in the battery case 50 is arranged in a facing direction.

  Further, plate-like spacers 30 are arranged in the gaps between the cells 20 arranged in this way. 3 to 6 are views schematically showing spacers 30 arranged between adjacent unit cells 20, FIG. 3 is a top view, FIG. 4 is a front view, FIG. 5 is a side view, and FIG. FIG.

  As shown in FIGS. 3 to 6, the spacer 30 is a resin-made plate-like member and is disposed so as to contact both of the adjacent unit cells 20. A mounting table 31 on which the unit cell 20 is mounted is attached to the spacer 30. The spacer 30 includes an upper end opening 32 opened at the upper end of the spacer 30, a lower end opening 34 opened at the lower end of the spacer 30, and a communication path 36 that connects the upper end opening 32 and the lower end opening 34. Yes. In this embodiment, the upper end opening 32 is an opening for introducing dust mixed from the outside into the communication path 36 of the spacer 30. The lower end opening 34 is an opening for discharging dust that has passed through the communication path 36 of the spacer 30 to the outside.

  In the width direction W, the opening width w 1 of the upper end opening 32 is larger than the opening width w 2 of the lower end opening 34. In the width direction W, the upper end opening 32 is formed with the same width as the entire width of the spacer 30. In this embodiment, the lower end opening 34 is provided in the center of the lower surface of the spacer 30 in the width direction W. The lower end opening 34 is formed in the width direction W with a width of 1/8 to 1/4 (for example, about 1/6) of the entire width of the spacer 30. The communication path 36 has an inclined surface 38 that gradually inclines so that the width in the width direction W widens toward the upper end opening 32 and narrows toward the lower end opening 34. In this embodiment, the communication path 36 is formed in a Y shape having an inclined surface 38 and a vertical surface 39. The inclined surface 38 extends downwardly from the upper end opening 32. The vertical surface 39 extends vertically upward from the lower end opening 34. The upper end of the vertical surface 39 is connected to the lower end of the inclined surface 38.

  The inclination angle θ of the inclined surface 38 with respect to the width direction W is not particularly limited. However, from the viewpoint of suppressing the accumulation of dust on the inclined surface 38, for example, the angle is preferably 30 degrees or more, and preferably 35 degrees. Above, more preferably 40 degrees or more. The upper limit of the inclination angle θ of the inclined surface 38 is not particularly limited, but is preferably 60 degrees or less, for example, 50 degrees or less, typically 45 degrees or less from the viewpoint of securing a space for a cooling path described later. The technique disclosed here can be preferably implemented in an aspect in which the inclination angle θ of the inclined surface 38 is not less than 30 degrees and not more than 60 degrees.

  In this embodiment, a protrusion 35 is provided on the lower surface of the spacer 30. In the illustrated example, the two protrusions 35 are arranged at a predetermined interval with the lower end opening 34 interposed therebetween. The lower surface of the spacer 30 is lifted by the projection 35, and a space is formed below the lower end opening 34. The dust 90 discharged from the lower end opening 34 is accumulated in this space.

  In this embodiment, the spacer 30 includes a cooling medium introduction port 42 through which a cooling medium is introduced by opening on a side surface in the width direction W of the spacer 30, and a cooling medium by opening at a side surface in the width direction W of the spacer 30 Is provided with a cooling medium outlet 44 and a cooling path 46 that connects the cooling medium inlet 42 and the cooling medium outlet 44. In the illustrated example, the cooling medium introduction port 42, the cooling medium discharge port 44, and the cooling path 46 are respectively provided on the left and right side surfaces of the spacer 30 in the width direction W. The cooling medium inlet 42 is provided at the upper part of the left and right side surfaces of the spacer 30. The cooling medium discharge port 44 is provided at the lower part of the left and right side surfaces of the spacer 30. A cooling path 46 extending from the cooling medium introduction port 42 to the cooling medium discharge port 44 is provided with a plurality of rectifying surfaces 48 that regulate the flow of the cooling medium. In this embodiment, the cooling medium is air (cooling air).

  In the assembled battery 10, dust mixed from the outside is introduced into the upper end opening 32 of the spacer 30 as shown in FIG. 4. The dust introduced from the upper end opening 32 slides down the inclined surface 38 and the vertical surface 39 of the communication path 36 and reaches the lower end opening 34. In FIG. 4, an arrow 92 indicates a route in which dust introduced from the upper end opening 32 passes through the communication path 36 and reaches the lower end opening 34. The dust that has reached the lower end opening 34 is discharged downward from the lower end opening 34 and accumulates in a space formed below the lower end opening 34 (see dust 90).

  According to the assembled battery 10 configured as described above, as shown in FIGS. 1 to 6, dust mixed from the outside is introduced into the communication path 36 from the upper end opening 32 of the spacer 30, and the inclined surface 38 of the communication path 36 is formed. Since it slides down and is discharged to the outside through the lower end opening 34, it is difficult for a situation in which dust accumulates on the upper surface of the unit cell 20 and the spacer 30 to bridge the unit cell 20 (battery case 50). Therefore, the disadvantage that the single cells 20 are short-circuited due to the sand dust bridging the single cells 20 can be eliminated or alleviated. As a result, it is possible to provide the assembled battery 10 having higher reliability than the conventional one.

  Further, according to the battery pack 10, since the inclination angle θ of the inclined surface 38 with respect to the width direction W is set to 30 ° or more, dust introduced from the upper end opening 32 accumulates on the inclined surface 38 of the communication path 36. It slides smoothly without doing. Therefore, the dust introduced from the upper end opening 32 can be more reliably discharged from the lower end opening 34.

  Further, according to the assembled battery 10, the protrusion 35 is provided on the lower surface of the spacer 30. By providing the protrusions 35 on the lower surface of the spacer 30 in this way, the lower surface of the spacer 30 is lifted, and a space for depositing dust 90 can be secured below the lower end opening 34. In this way, unlike the second embodiment to be described later, a process of covering the surface other than the upper surface of the unit cell 20 with an insulator becomes unnecessary, and the configuration of the unit cell 20 can be simplified.

  In the above embodiment, the spacer 30 includes the cooling medium introduction port 42 into which the cooling medium is introduced, the cooling medium discharge port 44 through which the cooling medium is discharged, the cooling medium introduction port 42, and the cooling medium discharge port 44. And a cooling path 46 to be connected. According to this configuration, the cooling air introduced from the cooling medium introduction port 42 passes through the cooling path 46, reaches the cooling medium discharge port 44, and is discharged to the outside from the cooling medium discharge port 44. While the cooling medium passes through the cooling path 46, the unit cell 20 in contact with the spacer 30 can be cooled. In this way, one spacer 30 can be provided with the function of discharging dust and the function of cooling the unit cell. Therefore, it is not necessary to separately provide a cooling spacer, and the configuration of the assembled battery 10 can be simplified.

Second Embodiment
FIG. 7 is a side view schematically showing the configuration of the assembled battery 110 according to the second embodiment. FIG. 8 is a front view schematically showing the configuration of the spacer 130 according to the second embodiment. As shown in FIGS. 7 and 8, the second embodiment is different from the first embodiment described above in that the protrusion 35 (see FIGS. 1 and 4) is not formed on the lower surface of the spacer 130. In this embodiment, the surface (four side surfaces and the lower surface) excluding the upper surface of each unit cell 120 is covered with an insulator (for example, a resin film) not shown. Since other forms are the same as those in the first embodiment, description thereof will be omitted.

  In this assembled battery 110, as shown in FIG. 8, dust mixed from the outside is introduced into the upper end opening 132 of the spacer 130. The dust introduced from the upper end opening 132 slides down the inclined surface 138 and the vertical surface 139 of the communication path 136 (passes through the communication path 136) and reaches the lower end opening 34. In FIG. 8, an arrow 192 indicates a route in which dust introduced from the upper end opening 132 passes through the communication path 136 and reaches the lower end opening 134. The dust that has reached the lower end opening 134 is accumulated and accumulated around the lower end opening 34 (see dust 190).

  According to the assembled battery 110 configured as described above, dust mixed in from the outside is introduced into the communication path 136 from the upper end opening 132 of the spacer 130, and slides down the inclined surface 138 of the communication path 136 and collects around the lower end opening 134. Therefore, it is difficult for the dust to accumulate on the upper surfaces of the unit cells 120 and the spacers 130 to bridge between the unit cells 120 (for example, the battery case). Therefore, the disadvantage that the single cells 120 are short-circuited due to the bridging between the single cells 120 by the sand dust can be eliminated or alleviated. In addition, when dust collects around the lower end opening 134, there is a possibility that a short circuit between the unit cells 120 may occur in the lower part of the unit cell 120. According to this configuration, the surface (4) except the upper surface of the unit cell 120. Since one side surface and the lower surface are covered with an insulator, a short circuit at the lower portion of the unit cell 120 can be suppressed. In this way, even if there is no space for providing protrusions on the lower surface of the spacer 130 and a sufficient space for dust to escape is not secured below the lower end opening 134, short-circuiting between the single cells 20 due to dust can be suppressed. Can do.

  As mentioned above, although the specific example of this invention was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  The assembled battery 10 disclosed herein is suitable as a power source mounted on a vehicle, for example, because short-circuiting between individual cells due to dust is suppressed and high performance can be exhibited. Therefore, the assembled battery 10 disclosed herein can be suitably used as a power source (typically a driving power source) for a motor mounted on a vehicle including an electric motor such as a hybrid vehicle or an electric vehicle.

10 assembled battery 20 single cell 30 spacer 32 upper end opening 34 lower end opening 35 protrusion 36 communication path 38 inclined surface 50 battery case 90 dust

Claims (1)

An assembled battery in which a plurality of chargeable / dischargeable cells are arranged in a predetermined direction,
A plate-like spacer disposed in a gap between the arranged single cells;
An upper end opening opened at an upper end of the spacer;
A lower end opening at the lower end of the spacer;
A communication path communicating the upper end opening and the lower end opening;
In the width direction perpendicular to the arrangement direction of the unit cells and the height direction of the unit cells, the opening width of the upper end opening is larger than the opening width of the lower end opening and the same width as the entire width of the spacer Formed,
The assembled battery has an inclined surface that is inclined so that a width of the communication path in the width direction is widened toward the upper end opening and is narrowed toward the lower end opening.

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