JP2012243597A - Battery pack, and square battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack composed of square batteries having protrusions for improving heat dissipation while having a small volume and excellent energy density even if adjoining square batteries are disposed so that the same faces face each other.SOLUTION: In a battery pack 100 in which a plurality of square batteries 200 are juxtaposed adjacently to each other, the square battery 200 has a positive electrode terminal 2 and a negative electrode terminal 3 on one face, when viewing one terminal from either one of the positive electrode terminal 2 and the negative electrode terminal 3, a side face looking toward the same side is set as a first side face P, a side face opposite to the first side face P is set as a second side face Q, a plurality of protrusions 4 are provided on the first side face P and the second side face Q, and projecting parts 10 and recessed parts 20 are thereby formed. The adjoining square batteries 200 are juxtaposed so that the first side faces P face each other and the second side faces Q face each other with their positive and negative polarities reversed, and the projecting part 10 of one of the adjoining square batteries 200 gets into the recessed part 20 of the other square battery.

Description

  The present invention relates to an assembled battery composed of a plurality of rectangular batteries and a rectangular battery constituting the assembled battery.

  When a plurality of single cells are assembled into an assembled battery, measures are taken for cooling, such as providing a gap between the single cells constituting the assembled battery. When an assembled battery is configured using a prismatic battery, in order to increase the surface area of the unit cell and improve heat dissipation, a projection or the like may be provided on the surface of the prismatic battery to form a heat sink.

  As a heat sink for forming an assembled battery with rectangular batteries, for example, as shown in Patent Document 1, protrusions are provided in a staggered arrangement on two opposing faces (two parallel faces) of the faces constituting the prismatic battery. It has been proposed to arrange the protruding portions so as not to face each other when the assembled battery is configured. Such an arrangement of the protrusions can suppress an increase in the volume of the assembled battery while improving the cooling performance. In order to improve the energy density of the assembled battery, it is desirable to make the volume as small as possible.

JP 2004-213922 A

  If the prismatic battery is provided with protrusions to improve heat dissipation as in the prior art described above, and the protrusions are arranged in a staggered manner, the prismatic batteries are arranged in the same direction to form an assembled battery. Convenient. However, depending on the positions of the positive electrode terminal and the negative electrode terminal provided in the prismatic battery, when the prismatic batteries are arranged in the same direction, the volume of the assembled battery may increase, leading to a decrease in energy density.

  For example, consider a case where both the positive electrode terminal and the negative electrode terminal are provided on the same surface (for example, the upper surface) of the prismatic battery. In this case, when adjacent batteries (referred to as battery A and battery B) are arranged in the same direction, the positive terminals and the negative terminals of battery A and battery B are adjacent to each other. Therefore, in the battery pack in which the battery A and the battery B are connected in series, the wiring that connects the positive terminal of the battery A and the negative terminal of the battery B (or the wiring that connects the negative terminal of the battery A and the positive terminal of the battery B) ) Must be lengthened. Wiring as described above, which increases resistance in an assembled battery, is not preferable, and it is practical to invert adjacent batteries so that the positive electrode terminal and the negative electrode terminal are close to each other.

  Further, for example, the positive electrode terminal is provided on a surface (for example, a side surface) of the rectangular battery, the negative electrode terminal is provided on a surface opposite to the side surface (a side surface parallel to the side surface), and the positive electrode terminal and the negative electrode terminal are provided. Let us consider a case where they are arranged eccentrically from the center of each side surface (for example, a case where the positive electrode terminal and the negative electrode terminal are arranged at the upper part of each side surface). Also in this case, when adjacent batteries (battery A and battery B) are arranged in the same direction and connected in series, the wiring becomes long as in the above example.

  In these examples, it is necessary to change the direction of the adjacent batteries so that the same surfaces of the battery A and the battery B face each other. For example, when both the positive electrode terminal and the negative electrode terminal are provided on the upper surface of the prismatic battery, the battery B is rotated by 180 degrees around the axis perpendicular to the upper surface through the center of the upper surface, and the battery A and the battery B It is necessary to make the same surface (side surface) face each other. When the batteries A and B are arranged in such a direction, the distance between the positive terminal of the battery A and the negative terminal of the battery B (or the distance between the negative terminal of the battery A and the positive terminal of the battery B) is shortened. Connection resistance between single cells in the battery can be reduced.

  However, the prior art does not consider an assembled battery having a configuration in which adjacent rectangular batteries are arranged so that the same surfaces face each other. When the related art is applied to the assembled battery having such a configuration, the projecting portion provided to improve heat dissipation collides with the adjacent battery, so that the assembled battery increases in volume and energy. The density may decrease.

  The present invention is an assembled battery having a small volume and excellent energy density even when adjacent prismatic batteries are arranged so that the same surfaces face each other, even if the prismatic batteries are provided with protrusions for improving heat dissipation. The purpose is to provide.

  The assembled battery according to the present invention has the following features.

  In the assembled battery in which a plurality of prismatic batteries are arranged adjacent to each other, the prismatic battery has a positive electrode terminal and a negative electrode terminal on one surface, and one of the positive electrode terminal and the negative electrode terminal is connected to the other. A side surface facing the same side when viewed is a first side surface, a side surface facing the first side surface is a second side surface, and a plurality of protrusions are formed on the first side surface and the second side surface. By disposing, a convex portion and a concave portion are formed. Adjacent prismatic batteries are arranged in parallel so that the positive and negative polarities are reversed and the first side surfaces or the second side surfaces face each other, and the convex portion of one of the prismatic batteries among the adjacent prismatic batteries. Has entered the recess of the other prismatic battery.

  According to the present invention, there is provided an assembled battery having a small volume and excellent energy density even when adjacent prismatic batteries are arranged so that the same surfaces face each other while providing protrusions on the rectangular batteries to improve heat dissipation. can do.

It is an external appearance perspective view of the cell which comprises the assembled battery by the 1st Embodiment of this invention. It is an external appearance perspective view of the assembled battery comprised using the square cell shown in FIG. It is a schematic diagram explaining the positional relationship of the projection part of an adjacent cell. It is a schematic diagram explaining the positional relationship of the protrusion part of an adjacent single cell in detail. It is an external appearance perspective view of the cell which comprises the assembled battery by the 2nd Embodiment of this invention. It is an external appearance perspective view of the assembled battery comprised using the square cell shown in FIG. It is an external appearance perspective view of the cell which comprises the assembled battery by the 3rd Embodiment of this invention. It is an external appearance perspective view of the assembled battery comprised using the square cell shown in FIG. It is a two-plane figure which shows the cell with which the projection part is provided in 3 surfaces. It is a two-plane figure which shows the cell with which the projection part is provided in 4 surfaces. It is a top view of the cell shown in FIG. 1, and is a diagram for explaining the position of the protrusion and how to take the offset. It is a figure which shows an example of the extension direction of the projection part of a cell, and the direction through which cooling air flows. It is a top view of the cell used for the assembled battery by embodiment of this invention. It is a top view of the cell used for the assembled battery by a comparative example. It is a top view of the assembled battery by embodiment of this invention. It is a top view of the assembled battery by a comparative example. It is a figure which shows the example of a flat cell. It is a figure which shows another example of a flat cell.

  A first embodiment of the present invention will be described.

  FIG. 1 is an external perspective view of a unit cell constituting the assembled battery according to the first embodiment of the present invention. The unit cell 200 is a rectangular parallelepiped battery, and includes a battery container 1 having a square shape having six surfaces, a positive electrode terminal 2, a negative electrode terminal 3, and a plurality of protrusions 4.

  The positive electrode terminal 2 and the negative electrode terminal 3 are provided on one surface of the battery case 1 (surface T which is the upper surface of the battery case 1 in FIG. 1), and are derived from a power generation element (not shown) inside the unit cell 200. External terminal. In FIG. 1, a rotation axis Z perpendicular to the surface T and passing through the center of the surface T is displayed. The rotation axis Z is a virtual axis used for explaining the arrangement of the unit cells 200 in the assembled battery.

  The plurality of protrusions 4 are used as heat sinks for cooling the unit cell 200, and in order to enhance the cooling effect, the two largest surfaces among the six surfaces of the battery case 1 (two surfaces facing each other, surface P in FIG. 1). And surface Q). The surface P and the surface Q on which the protrusions 4 are disposed are adjacent to the surface T on which the positive electrode terminal 2 and the negative electrode terminal 3 are provided on the long sides thereof. Further, the protrusion 4 extends along a direction parallel to the direction in which the cooling air for cooling the unit cell 200 flows when the assembled battery is configured. This direction is the direction of the rotation axis Z (direction perpendicular to the surface T) in the present embodiment, and is a direction parallel to the short sides of the surface P and the surface Q.

  The protrusion 4 may be formed directly on the battery container 1 or may be configured as a separate part that is joined to the battery container 1. By providing the protrusion 4, the convex portion 10 and the concave portion 20 are formed on the surface P and the surface Q. The protrusion 4 becomes the protrusion 10 and the area where the protrusion 4 is not provided (the area between the two protrusions 4 or the sides at both ends in the direction perpendicular to the extending direction of the protrusion 4, and these The region between the projections 4 closest to each of the sides is a recess 20.

  In addition, although the rectangular parallelepiped-shaped projection part 4 was shown in FIG. 1, in this embodiment and the following embodiment, the shape of the projection part 4 is not limited to a rectangular parallelepiped shape. For example, a prismatic shape such as a triangular prism or a quadrangular prism, or a semi-cylindrical shape may be used. Further, the size (width, length, and height) of the protrusion 4 can be arbitrarily determined according to the unit cell 200 or the assembled battery.

  On the surface P and the surface Q of the unit cell 200, a side at one end in a direction perpendicular to the direction in which the protrusion 4 extends (direction of the rotation axis Z) is referred to as a side R, and a side at the other end is referred to as a side S. Call. The side R and the side S will be described later with reference to FIG. 3B, but are used when describing the position of the protrusion 4.

  FIG. 2 is an external perspective view of an assembled battery configured using the rectangular unit cell shown in FIG. The assembled battery 100 is composed of a plurality of unit cells 200 arranged side by side adjacent to each other, and these unit cells 200 are fixed by the assembled battery frame 5. High voltage assembled battery 100 is obtained by connecting single cells 200 in series by bus bar 6. Moreover, the control circuit 7 may be attached to the assembled battery 100 for the purpose of controlling the voltage of each unit cell 200 as needed.

  An arrow in FIG. 2 indicates a direction 8 in which cooling air for cooling the unit cell 200 flows. The cooling air flows parallel to the extending direction of the protrusions 4 of the unit cell 200 and allows the assembled battery 100 to pass therethrough. Therefore, in the case of the configuration shown in FIG. 2, the cooling air is allowed to flow from the bottom to the top as indicated by the arrows in the drawing. Alternatively, the cooling air may flow from top to bottom in the direction opposite to the arrow.

  In the assembled battery 100, a plurality of unit cells 200 are arranged side by side, and the positive electrode terminal 2 and the negative electrode terminal 3 of the adjacent unit cells 200 are connected by a bus bar 6. At this time, as shown in FIG. 2, the adjacent unit cells 200 are preferably arranged so that the widest surfaces of the six surfaces of the unit cell 200 face each other with the positive and negative polarities reversed. When arranged in this way, the size of the assembled battery 100 in the three directions of length, width, and height can be reduced to reduce the volume. Furthermore, since the positive electrode terminal 2 and the negative electrode terminal 3 are adjacent to each other in the adjacent unit cell 200, the distance between the positive electrode terminal 2 and the negative electrode terminal 3 can be shortened.

  In order to arrange the unit cell 200 as shown in FIG. 2, any one unit cell (referred to as battery A) of the assembled battery 100 and the unit cell (referred to as battery B) adjacent thereto face the same surface. It is necessary to let The same surface is a surface facing the same side when the negative electrode terminal 3 (or the negative electrode terminal 3 to the positive electrode terminal 2) is viewed from the positive electrode terminal 2 of the unit cell 200. That is, using FIG. 1, since the surface facing the right side when viewing the negative electrode terminal 3 from the positive electrode terminal 2 is the surface P (the surface facing the left side is the surface Q), the surface P of the battery A It is necessary to arrange the battery A and the battery B so that the surface P of the battery B faces each other. In other words, referring to FIG. 1, from the state in which the surface P of the battery A and the surface Q of the battery B face each other (the state in which the battery A and the battery B are aligned in the same direction), It is necessary to place the battery A and the battery B with one of them rotated 180 degrees around the rotation axis Z.

  In the assembled battery 100 configured as described above, the protrusions 4 are formed in parallel to the rotation axis Z (that is, perpendicular to the surface T) so that the protrusions 4 of the adjacent unit cells 200 do not interfere with each other. Yes.

  The positions at which the protrusions 4 are provided on the surface P and the surface Q of the unit cell 200 will be described with reference to FIGS. 3A and 3B.

  FIG. 3A is a view of the assembled battery as viewed from above (the direction having the positive electrode terminal 2 and the negative electrode terminal 3), and is a schematic diagram for explaining the positional relationship between the protrusions of adjacent unit cells. In FIG. 3A, for simplicity, four unit cells 200 of the assembled battery 100 are shown. The unit cells 200 are arranged so that the same surfaces as the adjacent unit cells 200 face each other. That is, in the adjacent unit cells 200, the surface P and the surface P or the surface Q and the surface Q face each other.

  The protrusions 4 provided on the surface P and the surface Q of the unit cell 200 are provided so that when the same surface is opposed to the adjacent unit cell 200, the protrusions 4 on the opposing surfaces abut each other and do not interfere with each other. More specifically, if the adjacent unit cells 200 are the battery A and the battery B, the protrusions on the surface P of the battery A and the protrusions on the surface P of the battery B do not interfere with each other. Is provided on the surface P such that the protrusion P is located in a region where the protrusion on the surface P of the battery B does not exist. That is, the convex portion 10 formed on the surface P of the battery A enters the concave portion 20 formed on the surface P of the battery B.

  Similarly, with respect to the surface Q, the protrusion 4 is provided on the surface Q so that the protrusion on the surface Q of the battery A is located in a region where the protrusion on the surface Q of the battery B does not exist, and is formed on the surface Q of the battery A. The projected portion 10 is made to enter the recessed portion 20 formed on the surface Q of the battery B.

  The position of the protrusion 4 on the surface Q of the unit cell 200 will be described in more detail with reference to FIG. 3B. FIG. 3B is a diagram showing three unit cells 200 among the unit cells 200 shown in FIG. 3A, and is a schematic diagram for explaining in detail the positional relationship between the protrusions of adjacent unit cells. FIG. 3B shows three unit cells 200.

  On the surface Q of the unit cell 200, a side at one end in a direction (vertical direction on the paper surface) perpendicular to the direction in which the protrusion 4 extends (a direction perpendicular to the paper surface) is referred to as a side R, and a side at the other end is a side. S. At this time, on the surface Q, the region where the protrusion 4a is viewed from the side R may be in the region between the two adjacent protrusions 4b and 4c viewed from the side S. Alternatively, on the surface Q, the existence region viewed from the side S of the protrusion 4d closest to the side S may be in the region between the protrusion 4e and the side R closest to the side R.

  The arrangement of the protrusions 4 on the surface P of the unit cell 200 is the same as the arrangement of the protrusions 4 on the surface Q. That is, on the surface P of the unit cell 200, a side at one end in a direction perpendicular to the extending direction of the protrusion 4 is defined as a side R ', and a side at the other end is defined as a side S'. At this time, in the surface P, the existence region of the protrusion 4a 'seen from the side R' may be in the region between the two adjacent protrusions 4b 'and 4c' seen from the side S '. Alternatively, on the surface P, the existence region viewed from the side S ′ of the projection 4d ′ closest to the side S ′ may be in the region between the projection 4e ′ closest to the side R ′ and the side R ′. .

  As described above, when the protrusions 4 are provided, in the assembled battery 100 in which the unit cells 200 are arranged adjacent to each other so that the same surface faces each other, the protrusions 4 of the adjacent unit cells 200 abut each other and do not interfere with each other. It becomes a relationship. Therefore, the volume of the assembled battery 100 can be reduced. Furthermore, in the assembled battery 100, since the positive electrode terminal 2 and the negative electrode terminal 3 are adjacent to each other in the adjacent unit cell 200, the distance between the positive electrode terminal 2 and the negative electrode terminal 3 can be shortened. From the above, in the present embodiment, the protrusion 4 is provided on the unit cell 200 to improve heat dissipation, and the volume of the assembled battery 100 can be reduced, thereby preventing the energy density of the assembled battery 100 from being lowered. Can do.

  In the adjacent unit cells 200, the protrusion 4 of one unit cell 200 is provided so as to be positioned at the center between two adjacent protrusions 4 of the other unit cell 200, or the protrusion 4 extends. It is preferable to provide it so as to be located at the center between the protrusion closest to the side at one end in the direction perpendicular to the direction to the side and the side at one end. That is, in the adjacent unit cells 200, the protrusion 10 that is the protrusion 4 of one unit cell 200 is positioned at the center of the recess 20 that is the region where the protrusion 4 of the other unit cell 200 is not provided. It is preferable to provide in. If it does in this way, the channel of cooling air can be secured equally. For example, in FIG. 3B, it is preferable to provide the protruding portion 4a so as to be positioned at the center of the two protruding portions 4b and 4c, or to set the protruding portion 4d so as to be positioned at the center of the protruding portion 4e and the side R.

  Further, in the adjacent unit cells 200, the plurality of protrusions 4 of the other unit cell 200 may be positioned between two adjacent protrusions 4 of the one unit cell 200. That is, you may make it the some convex part 10 of the other unit cell 200 enter into the recessed part 20 of one unit cell 200. FIG. In other words, between the two adjacent protrusions 4 of one unit cell 200 or the protrusion closest to the edge at one end in the direction perpendicular to the extending direction of the protrusion 4 and the edge at one end. There may be a region where a plurality of protrusions of the other unit cell 200 exist.

  Further, on the surface of the unit cell 200 on which the protrusion 4 is provided, the protrusion closest to the side at one end in the direction perpendicular to the direction in which the protrusion 4 extends (the first protrusion as viewed from this side) is Take an appropriate offset from this side, place it at an appropriate position, and place the projection farthest from this side (the last projection when viewed from this side, ie, the projection closest to the side at the other end) from the side at the other end. An appropriate offset is taken from and provided at an appropriate position. 3B, for example, on the surface Q, the protrusion 4e is arranged with an appropriate offset from the side R, and the protrusion 4d is arranged with an appropriate offset from the side S. An appropriate offset method will be described later.

  Thus, if the protrusion 4 is provided by taking an appropriate offset, in the assembled battery 100, the positions of the end portions of the unit cells 200 can be aligned. In the example of FIG. 3B, adjacent sides R and S can be arranged on a single plane. That is, all the unit cells 200 can be arranged at the same position in the direction perpendicular to the direction in which the protrusions 4 of the unit cells 200 extend (up and down direction in the drawing). By disposing the single battery 200 in this way, an increase in the volume of the assembled battery 100 can be suppressed, and a decrease in energy density can be prevented.

  In addition, the above description does not unambiguously determine the positional relationship and the offset amount of the protrusions of the unit cell (rectangular battery) constituting the assembled battery according to the present invention. Needless to say, the positional relationship and the offset amount of the protrusions should be appropriately selected according to the individual design of the assembled battery.

  A second embodiment of the present invention will be described. In the second embodiment, the description of parts common to the first embodiment is omitted.

  FIG. 4 is an external perspective view of a unit cell constituting the assembled battery according to the second embodiment of the present invention. 4, the same reference numerals as those in FIG. 1 denote the same or corresponding components as those in FIG.

  The unit cell 200 includes the positive electrode terminal 2 and the negative electrode terminal 3 on the side surfaces of the battery container 1 facing each other in the unit cell constituting the assembled battery according to the first embodiment. The positive terminal 2 is installed at the center of the short side U of the battery case 1, and the negative terminal 3 (not shown) is installed at the center of the short side V (not shown) parallel to the short side U. The short side surface U and the short side surface V are adjacent to the short side of the surface P and the surface Q on which the protrusions 4 are provided (also adjacent to the short side of the surface T).

  Also in this embodiment, the protrusion 4 extends along a direction parallel to the direction in which the cooling air for cooling the unit cell 200 flows when the assembled battery is configured, that is, along the rotation axis Z. In other words, the protrusion 4 extends in a direction parallel to the short side U (or short side V) and in a direction parallel to the short sides of the surface P and the surface Q. The positions of the protrusions 4 on the surface P and the surface Q are also the same as in the first embodiment described with reference to FIGS. 3A and 3B.

  FIG. 5 is an external perspective view of an assembled battery configured using the rectangular unit cell shown in FIG. 5, the same reference numerals as those in FIG. 2 denote the same or corresponding components as those in FIG. The unit cells 200 are connected in series by the bus bar 6. Cooling air for cooling the cell 200 flows in parallel to the direction in which the protrusions 4 of the cell 200 extend, and allows the assembled battery 100 to pass therethrough. Therefore, also in the case of the configuration shown in FIG. 5, the cooling air is made to flow from the bottom to the top along the direction 8 indicated by the arrow in the drawing, or from the top to the bottom in the direction opposite to the arrow.

  Also in FIG. 5, the same surface of any one unit cell of the assembled battery 100 and the unit cell adjacent thereto are opposed to each other. That is, the surface P of the battery A and the surface P of the battery B adjacent thereto are opposed to each other. As described with reference to FIG. 1 and FIG. 2 in the first embodiment, this state is from the state where the surface P of the battery A and the surface Q of the battery B face each other. One of them is rotated 180 degrees around the rotation axis Z.

  In the present embodiment, the positions of the protrusions 4 on the surface P and the surface Q are the same as those in the first embodiment. Therefore, similarly to the first embodiment, when the assembled battery 100 is configured, the protrusions 4 of the adjacent unit cells 200 face each other and do not interfere with each other. For this reason, the volume of the assembled battery 100 can be reduced by reducing the dimensions in the three directions of length, width, and height. Further, in the assembled battery 100, since the short side surface U and the short side surface V are arranged adjacent to each other in the adjacent unit cell 200, the positive electrode terminal 2 and the negative electrode terminal 3 are also arranged alternately, and the distance between the positive electrode terminal 2 and the negative electrode terminal 3 is shortened. can do. From the above, in the present embodiment, the protrusion 4 is provided on the unit cell 200 to improve heat dissipation, and the volume of the assembled battery 100 can be reduced, thereby preventing the energy density of the assembled battery 100 from being lowered. Can do.

  A third embodiment of the present invention will be described. In the third embodiment, description of portions common to the second embodiment is omitted.

  FIG. 6 is an external perspective view of a unit cell constituting an assembled battery according to the third embodiment of the present invention. 6, the same reference numerals as those in FIG. 4 denote the same or corresponding components as those in FIG.

  The unit cell 200 is a unit cell constituting the assembled battery according to the second embodiment, in which the positive electrode terminal 2 is eccentrically arranged from the center of the short side U and is installed on the upper side, and the negative electrode terminal 3 (not shown) is connected to the short side V ( (Not shown) and is installed at the top eccentrically.

  In the present embodiment, the extending direction of the protrusions 4 and the positions on the surfaces P and Q are the same as those in the second embodiment.

  FIG. 7 is an external perspective view of an assembled battery configured using the rectangular unit cell shown in FIG. 7, the same reference numerals as those in FIG. 5 denote the same or corresponding components as those in FIG. The unit cells 200 are connected in series by the bus bar 6.

  In the present embodiment, the arrangement of the unit cells 200 constituting the assembled battery 100 is the same as that in the second embodiment.

  Therefore, similarly to the first embodiment, when the assembled battery 100 is configured, the protrusions 4 of the adjacent unit cells 200 face each other and do not interfere with each other. For this reason, the volume of the assembled battery 100 can be reduced by reducing the dimensions in the three directions of length, width, and height. Further, in the assembled battery 100, since the short side surface U and the short side surface V are arranged adjacent to each other in the adjacent unit cell 200, the positive electrode terminal 2 and the negative electrode terminal 3 are also arranged alternately, and the distance between the positive electrode terminal 2 and the negative electrode terminal 3 is shortened. can do. From the above, in the present embodiment, the protrusion 4 is provided on the unit cell 200 to improve heat dissipation, and the volume of the assembled battery 100 can be reduced, thereby preventing the energy density of the assembled battery 100 from being lowered. Can do.

  In the above embodiment, the protrusions 4 are provided only on the widest two faces (two faces facing each other) of the faces of the unit cell 200. The protrusions 4 can be provided on surfaces other than the widest two surfaces, and can be provided on three or four surfaces of the unit cell 200. Specifically, the surface other than the widest two surfaces is a surface adjacent to the surface on which the protrusions 4 are disposed, and is a surface perpendicular to the rotation axis Z. The protrusion 4 may be omitted from the surface having at least one of the positive electrode terminal 2 and the negative electrode terminal 3. By providing the protrusions 4 on the three or four surfaces of the unit cell 200, the cooling efficiency of the unit cell 200 can be further increased. Needless to say, whether or not to provide the protrusions 4 other than the widest two surfaces should be appropriately selected according to the design conditions of the assembled battery 100. Hereinafter, the case where the protrusion part 4 is provided in the 3rd surface or 4th surface of the cell 200 is demonstrated using FIG. 8 and FIG.

  FIG. 8 is a two-side view showing the unit cell 200 in which the protrusions 4 are provided on the three sides in the unit cell shown in FIG. 1. 8, the same reference numerals as those in FIG. 1 denote the same or corresponding components as those in FIG. In addition to the surface P and the surface Q, the protrusion 4 is also provided on the surface W (the bottom surface of the battery container 1) facing the surface T on which the positive electrode terminal 2 and the negative electrode terminal 3 are provided. And the surface W are continuous. The surface W is a surface in which the positive electrode terminal 2 and the negative electrode terminal 3 are not installed among the surfaces perpendicular to the rotation axis Z.

  By providing the protrusions 4 as shown in FIG. 8, the cooling performance of the unit cell 200 can be increased. When the protrusions 4 are provided at fixed positions corresponding to each other on the surface P, the surface Q, and the surface W, it is easy to provide the protrusions 4 continuous over the three surfaces P, Q, and W. When the protrusions 4 are provided at positions that do not correspond to the surfaces P and Q (for example, staggered arrangement), it is difficult to provide the protrusions 4 that are continuous over the three surfaces P, Q, and W.

FIG. 9 is a two-side view showing the unit cell 200 in which the protrusions 4 are provided on the four sides in the unit cell shown in FIG. 4. 9, the same reference numerals as those in FIG. 4 denote the same or corresponding components as those in FIG. In addition to the surface P and the surface Q, the protrusion 4 is also provided on the surface T and the surface W facing the surface T, and the surface P, the surface Q, the surface T, and the surface W are continuous. The surface T and the surface W are surfaces perpendicular to the rotation axis Z, and are surfaces on which neither the positive electrode terminal 2 nor the negative electrode terminal is installed. That is, the protrusion 4 is continuous on four surfaces other than the two surfaces of the surface on which the positive electrode terminal 2 is installed and the surface on which the negative electrode terminal 3 is installed. The cooling property of the unit cell 200 can be made higher than in the case of FIG. If the protrusions 4 are provided at fixed positions corresponding to each other on the surface P, the surface Q, the surface T, and the surface W, it is easy to provide the protrusions 4 continuous over the four surfaces P, Q, T, and W. It is. When the protrusions 4 are provided at positions that do not correspond to the surface P and the surface Q (for example, staggered arrangement), it is difficult to provide the protrusions 4 that are continuous over the four surfaces P, Q, T, and W. Become.

  Even when the positive electrode terminal 2 and the negative electrode terminal 3 are eccentric from the centers of the short side face U and the short side face V, respectively, as in the unit cell 200 shown in FIG. 6, as shown in FIG. , Q, T, and W can be provided with continuous protrusions 4.

  With reference to FIG. 10, the position of the protrusion 4 on the surface of the unit cell 200 where the protrusion 4 is provided and how to take the offset will be described. FIG. 10 is a top view of the unit cell 200 shown in FIG. The protrusions 4 are assumed to have a thickness B and are arranged at a constant interval (pitch C).

  As described with reference to FIG. 3B, the offset of the protruding portion 4 is a side (one side) in a direction perpendicular to the extending direction of the protruding portion 4 on the surface of the unit cell 200 where the protruding portion 4 is provided ( This is the distance from the side of the projection closest to side S or side R). In FIG. 10, the offset of the protrusion closest to the side S (distance from the side S) is A, and the offset of the protrusion closest to the side R (distance from the side R) is D.

  In the unit cell 200, A = B, A + B + D = C. If it does in this way, in the assembled battery 100, the position of the edge part of the cell 200 can be aligned on a straight line. That is, in the assembled battery 100, the adjacent sides R and S can be arranged on a single plane.

  It is preferable from the viewpoint of the cooling efficiency of the unit cell 200 that the protruding portion 4 is installed on the flat portion of the widest area of the battery case 1. In addition, it is preferable in terms of cooling efficiency that the protrusions 4 extend along the direction in which the cooling air flows.

  FIG. 11 is a diagram illustrating an example of the extending direction of the protrusions 4 of the unit cell 200 and the direction 8 in which the cooling air flows. In FIG. 11, the protrusion 4 is extended in parallel with the direction 8 in which the cooling air flows.

  In the assembled battery 100, when the interval between the adjacent unit cells 200 is the same as the height (the length in the protruding direction) of the protrusions 4, the top part (the protruding surface) of the protrusions 4 is the protrusions of the adjacent unit cells 200. 4 is in contact with the surface of a region where 4 does not exist (a region between two adjacent protrusions 4). This is preferable from the viewpoint of volume energy density because the interval between adjacent unit cells 200 can be minimized. However, this is not the case when it is necessary to increase the flow passage area of the cooling air.

  Further, if the protrusion 4 is provided so as to be positioned at the center between the two adjacent protrusions 4 of the adjacent unit cells 200, the flow passage cross-sectional area of the cooling air can be made uniform, and the unit cell 200. Can be cooled evenly. However, the position of the protrusion 4 is not limited to this. For example, since heat tends to be trapped in the central portion of the unit cell 200, in the central portion, the interval between the protrusions 4 can be widened to increase the flow passage cross-sectional area of the cooling air, thereby promoting cooling. Of course, a design that reduces the temperature distribution of the entire unit cell 200 or the assembled battery 100 by appropriately determining the position of the protruding portion 4 is also useful.

  The results of comparing the volumes of the assembled battery according to the embodiment of the present invention and the assembled battery according to the comparative example will be described with reference to FIGS. In both assembled batteries, eight unit cells were arranged side by side, and the volume of only the unit cell portion was determined.

  FIG. 12 is a top view of the unit cell 200 used in the assembled battery according to the embodiment of the present invention, and FIG. 13 is a top view of the unit cell 210 used in the assembled battery according to the comparative example. 12 and 13 show dimensions in millimeters. The single cell 200 shown in FIG. 12 and the single cell 210 shown in FIG. 13 are provided with the positive electrode terminal 2 and the negative electrode terminal 3 on the upper surface of the battery container 1 in the same manner as the single cell 200 shown in FIG.

  In the unit cell 200 shown in FIG. 12, the thickness B of the protrusions 4 shown in FIG. 10 is 1 mm, the pitch C is 6 mm, the offset A is 1 mm, and the offset D is 4 mm. In the unit cell 210 shown in FIG. 13, the thickness B of the protrusions 4 shown in FIG. 10 is 1 mm, the pitch C is 6 mm, the offset A is 2.5 mm, and the offset D is 2.5 mm. Further, although not shown, the height of the unit cell 200 and the unit cell 210 (the length in the direction perpendicular to the paper surface, the length in the direction of the rotation axis Z in FIG. 1) is 30 mm. Thus, the unit cell 200 and the unit cell 210 differ only in the magnitudes of the offset A and the offset D. Moreover, the offset A and the offset D are not equal in the cell 200, and the offset A and the offset D are equal in the cell 210.

  FIG. 14 is a top view of the assembled battery 100 according to the embodiment of the present invention, and FIG. 15 is a top view of the assembled battery 110 according to the comparative example. In FIG. 14 and FIG. 15, only the cell portion is shown for simplicity.

  The assembled battery 100 shown in FIG. 14 includes the single battery 200 shown in FIG. Since the unit cell 200 has an offset A and an offset D which are not equal, the top portion (projection surface) of the protrusion 4 is an area where the protrusion 4 of the adjacent unit cell 200 does not exist (an area between two adjacent protrusions 4). ). Therefore, the protrusions 4 are associated with each other in the adjacent unit cell 200 and do not interfere with each other. For this reason, the interval between the adjacent unit cells 200 is the same as the height of the protrusion 4 (2 mm). For this reason, the volume of the assembled battery 100 can be made as small as possible.

  The assembled battery 110 shown in FIG. 15 includes the unit cell 210 shown in FIG. Since the unit cell 210 has the same offset A and offset D, the top portion (projection surface) of the projection 4 is in contact with the top of the projection 4 of the adjacent unit cell 210. Therefore, the protrusions 4 come into contact with each other and interfere with each other in the unit cell 200. For this reason, the interval between the adjacent unit cells 200 is twice (4 mm) the height of the protrusion 4.

The volume of the assembled battery 100 according to the embodiment of the present invention was 288.36 cm ³ , and the volume of the assembled battery 110 according to the comparative example was 311.04 cm ³ . Therefore, the assembled battery 100 according to the embodiment of the present invention was able to achieve a volume reduction of about 7% compared to the assembled battery 110 according to the comparative example.

  As described above, the position of the protrusion 4 and the offset of the unit cell using the same unit cell as the unit cell 200 shown in FIG. 1 (the unit cell in which the positive electrode terminal 2 and the negative electrode terminal 3 are provided on the upper surface T of the battery container 1). I explained how to take it. In these explanations, the unit cell 200 is a unit cell as shown in FIG. 4 or 6 (a unit cell in which the short side surfaces U and V of the battery container 1 are provided with the positive electrode terminal 2 and the negative electrode terminal 3). Can be applied. Therefore, even an assembled battery using a single battery as shown in FIG. 4 or FIG. 6 can achieve volume reduction and improve energy density.

  In the above embodiment, a rectangular parallelepiped battery has been described as an example of the single battery 200, but the shape of the single battery 200 is not limited to a rectangular parallelepiped as long as it is a square battery. Further, a curved surface may be included in the surface constituting the unit cell 200. For example, the unit cell 200 may be a flat rectangular battery. Any prismatic battery having a shape in which a plurality of protrusions 4 can be provided on two opposing surfaces can be used for a single battery constituting an assembled battery according to the present invention.

  16 and 17, a flat unit cell 200 in which the shape of the surface having the positive electrode terminal 2 and the negative electrode terminal 3 is a rounded rectangular shape (a shape composed of two parallel sides and two semicircles having the same length). An example of 16, the same reference numerals as those in FIG. 1 indicate the same or corresponding components as those in FIG. 1, and in FIG. 17, the same reference numerals as those in FIG. 4 indicate the same or corresponding components as those in FIG. In the unit cell 200 shown in FIG. 16, the shape of the surface T (the upper surface of the battery case 1) and the surface W (the bottom surface of the battery case 1 (not shown)) facing the surface T are rounded rectangles. The unit cell 200 shown in FIG. 17 has a rounded rectangular shape on a surface U (short side surface of the battery case 1) and a surface V (short side surface of the battery case 1 (not shown)) facing the surface U.

  Even in the assembled battery using the flat unit cell 200 as shown in FIGS. 16 and 17, the protrusion 4 is provided as described in the above embodiment to reduce the volume and improve the energy density. Can be made.

  DESCRIPTION OF SYMBOLS 1 ... Battery container, 2 ... Positive electrode terminal, 3 ... Negative electrode terminal, 4, 4a, 4b, 4c, 4e ... Projection part, 5 ... Assembly battery frame, 6 ... Bus bar, 7 ... Control circuit, 8 ... Direction where cooling air flows DESCRIPTION OF SYMBOLS 10 ... convex part, 20 ... recessed part, 100 ... assembled battery, 110 ... assembled battery by a comparative example, 200 ... single battery, 210 ... single battery by a comparative example, P, Q ... surface provided with the projection part, R, S ... the side of the surface provided with the protrusions at the end perpendicular to the direction in which the protrusions extend, T ... the upper surface of the battery container, U, V ... the short side surface of the battery container, W ... the bottom surface of the battery container, Z: A rotation axis.

Claims (16)

In an assembled battery in which a plurality of prismatic batteries are arranged next to each other,
The prismatic battery
Having a positive terminal and a negative terminal on one surface;
When the other of the positive electrode terminal and the negative electrode terminal is viewed from one side, the side surface facing the same side is the first side surface,
A side surface facing the first side surface is a second side surface,
Protrusions and recesses are formed by arranging a plurality of protrusions on the first side surface and the second side surface,
Adjacent square batteries are arranged side by side so that the positive and negative polarities are reversed and the first side surfaces or the second side surfaces face each other.
Of the adjacent square batteries, the convex part of one of the square batteries has entered the concave part of the other square battery,
A battery pack characterized by that. In an assembled battery in which a plurality of prismatic batteries are arranged next to each other,
The prismatic battery
Having positive and negative terminals on opposite sides,
When the other of the positive electrode terminal and the negative electrode terminal is viewed from one side, the side surface facing the same side is the first side surface,
A side surface facing the first side surface is a second side surface,
Protrusions and recesses are formed by arranging a plurality of protrusions on the first side surface and the second side surface,
Adjacent square batteries are arranged side by side so that the positive and negative polarities are reversed and the first side surfaces or the second side surfaces face each other.
Of the adjacent square batteries, the convex part of one of the square batteries has entered the concave part of the other square battery,
A battery pack characterized by that. In an assembled battery in which a plurality of prismatic batteries are arranged next to each other,
The prismatic battery
Having a positive terminal and a negative terminal on one surface;
When the other of the positive electrode terminal and the negative electrode terminal is viewed from one side, the side surface facing the same side is the first side surface,
A side surface facing the first side surface is a second side surface,
A plurality of protrusions are disposed on the first side surface and the second side surface so as to extend along one side of the side surface,
Adjacent square batteries are arranged side by side so that the positive and negative polarities are reversed and the first side surfaces and the second side surfaces face each other.
In the first side surface and the second side surface, the region where the protrusion is present when viewed from a side at one end in a direction perpendicular to the extending direction of the protrusion is at the other end in the vertical direction. In the region between two adjacent protrusions as seen from the side, or in the region between the projections closest to the side at the other end and the side at the other end,
A battery pack characterized by that. In an assembled battery in which a plurality of prismatic batteries are arranged next to each other,
The prismatic battery
Having positive and negative terminals on opposite sides,
When the other of the positive electrode terminal and the negative electrode terminal is viewed from one side, the side surface facing the same side is the first side surface,
A side surface facing the first side surface is a second side surface,
A plurality of protrusions are disposed on the first side surface and the second side surface so as to extend along one side of the side surface,
Adjacent square batteries are arranged side by side so that the positive and negative polarities are reversed and the first side surfaces and the second side surfaces face each other.
In the first side surface and the second side surface, the region where the protrusion is present when viewed from a side at one end in a direction perpendicular to the extending direction of the protrusion is at the other end in the vertical direction. In the region between two adjacent protrusions as seen from the side, or in the region between the projections closest to the side at the other end and the side at the other end,
A battery pack characterized by that. The assembled battery according to claim 1 or 3,
The protrusion is an assembled battery extending in a direction perpendicular to the surface having the positive terminal and the negative terminal. The assembled battery according to claim 2 or 4,
The protrusion is an assembled battery extending in a direction parallel to the side surface having the positive electrode terminal or the negative electrode terminal. The assembled battery according to any one of claims 1 to 4,
An assembled battery in which a protrusion is disposed on a surface adjacent to the side surface on which the protrusion is disposed so as to be continuous with the protrusion. The assembled battery according to claim 1 or 2,
The assembled battery in which the convex portion of one of the adjacent rectangular batteries enters the central portion of the concave portion of the other rectangular battery. The assembled battery according to claim 3 or 4,
In the first side surface and the second side surface, the region where the protrusion is present when viewed from a side at one end in a direction perpendicular to the extending direction of the protrusion is at the other end in the vertical direction. Located in the center of the region between two adjacent projections as viewed from the side, or in the center of the region between the projection at the other end and the side at the other end Assembled battery. The assembled battery according to claim 1 or 2,
The assembled battery in which the plurality of convex portions of one of the adjacent rectangular batteries enter one of the concave portions of the other rectangular battery. The assembled battery according to claim 3 or 4,
In the first side surface and the second side surface, the region where the plurality of protrusions are present when viewed from one side in a direction perpendicular to the direction in which the protrusions extend is the other end in the vertical direction The battery pack is located in a region between two adjacent protrusions as viewed from the side, or in a region between a protrusion closest to the side at the other end and the side at the other end. The assembled battery according to claim 1,
The protrusions extend along one side of the first side surface and the second side surface, are arranged at equal intervals, and are on a side at one end in a direction perpendicular to the extending direction. An assembled battery in which the distance between the nearest protrusion and the side at the one end is different from the distance between the protrusion at the other end in the perpendicular direction and the side at the other end. The assembled battery according to claim 2,
The protrusions extend along one side of the first side surface and the second side surface, are arranged at equal intervals, and are on a side at one end in a direction perpendicular to the extending direction. An assembled battery in which the distance between the nearest protrusion and the side at the one end is different from the distance between the protrusion at the other end in the perpendicular direction and the side at the other end. The assembled battery according to claim 3 or 4,
The protrusions are arranged at equal intervals on the first side surface and the second side surface, and are closest to a side at one end in a direction perpendicular to the extending direction, and a side at the one end And the distance between the protrusion closest to the side at the other end in the vertical direction and the side at the other end. Having a positive terminal and a negative terminal on one surface;
One surface adjacent to the surface having the positive terminal and the negative terminal is a first surface,
The surface facing the first surface is the second surface,
A plurality of protrusions are arranged on the first surface and the second surface so as to extend along one side of the surface,
Adjacent square batteries are used in a battery assembly in which positive and negative polarities are reversed and the first surfaces and the second surfaces face each other.
In the first surface and the second surface, a region where the protrusion is present when viewed from a side at one end in a direction perpendicular to the extending direction of the protrusion is at the other end in the vertical direction. In the region between two adjacent protrusions as seen from the side, or in the region between the projections closest to the side at the other end and the side at the other end,
A prismatic battery characterized by the above. Having positive and negative terminals on opposite faces,
One surface adjacent to the surface having the positive electrode terminal as a first surface,
The surface facing the first surface is the second surface,
A plurality of protrusions are arranged on the first surface and the second surface so as to extend along one side of the surface,
Adjacent square batteries are used in a battery assembly in which positive and negative polarities are reversed and the first surfaces and the second surfaces face each other.
In the first surface and the second surface, a region where the protrusion is present when viewed from a side at one end in a direction perpendicular to the extending direction of the protrusion is at the other end in the vertical direction. In the region between two adjacent protrusions as seen from the side, or in the region between the projections closest to the side at the other end and the side at the other end,
A prismatic battery characterized by the above.

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