JP2011159597A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack that can excellenty fix square batteries and improve manufacturing yield and manufacturing efficiency. <P>SOLUTION: The battery pack includes a plurality of square batteries 1 respectively having a metallic can and an insulating outer package and a case having a first support member and a second support member forming a plurality of fixing parts 50 together with the first support member. Each fixing part 50 has a first contact part 60 and a second contact part 70. The first contact part 60 includes protrusions 61, 62 while the second contact part 70 includes protrusions 71, 72. The protrusion 61 is in contact with the side face S within a range of 22% of the length of the side face S from a corner A1 and is at least partially in contact with the side face S within a range of 17-22% of the length of the side face S from the corner A1. The protrusion 71 is in contact with the side face S within a range of 22% of the length of the side face S from a corner A2 and is at least partially in contact with the side face S within a range of 17-22% of the length of the side face S from the corner A2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an assembled battery, and more particularly, to an assembled battery having a plurality of prismatic batteries.

  In general, an assembled battery including a plurality of batteries is known as a power source. The plurality of batteries are connected in series or in parallel by a bus bar. A secondary battery such as a lithium ion secondary battery is used as the battery. Moreover, the assembled battery includes a case, and a plurality of batteries are accommodated in the case (see, for example, Patent Documents 1 and 2).

  A square battery as a battery includes a metal can, a predetermined electrode coil, an electrolyte solution, and the like housed in the metal can. In the prismatic battery, the metal can is often at the same potential as the negative electrode terminal or the positive electrode terminal. For example, considering the case where the metal can is at the same potential as the positive electrode terminal, if a conductive part (for example, the square battery itself) is accidentally dropped onto the square battery, the negative electrode terminal and the positive electrode terminal Or the negative electrode terminal and metal cans may contact, and the accident which short-circuits may occur. This short circuit accident tends to occur during an assembly operation for incorporating a plurality of prismatic batteries.

  When a high-power large-capacity prismatic battery is short-circuited externally, a short-circuit with a large current occurs in the prismatic battery, and there is a risk that the prismatic battery will generate heat or burst. In this case, the influence on the worker during the assembly work may also occur. Therefore, the square battery is formed by covering a metal can with an insulating outer package. Thereby, a short circuit accident can be prevented.

JP 2006-338934 A JP 2008-251352 A

  As the insulating outer package, a heat-shrinkable or adhesive insulating film may be used. In the case of a square battery covered with an insulating outer package, the thickness tolerance of the insulating outer package is not small. When a heat-shrinkable insulating film is used for the insulating outer package, the shrinkage varies depending on how heat is applied, and the film thickness of the insulating film becomes uneven.

  In order to fix the square battery covered with such an insulating film, the square battery is inserted into the case. When the insertion slot formed on the insertion surface of the case for inserting the prismatic battery into the case is approximately the same size as the prismatic battery, the insulation film of the prismatic battery hits the insertion slot, and the rear surface of the film is the exterior If the square battery is forcibly inserted into the opening of the case, problems such as turning over the insulating film will occur.

  Therefore, it is conceivable to set the case insertion opening to a size larger than that of the square battery to eliminate problems such as turning over the insulating film. However, in this case, the case cannot fix the square battery. For this reason, when external impact or vibration is applied to the battery pack, improper force is applied to the bus bar mounting part, positive and negative bipolar terminals, etc., and the risk of heat generation, ignition, etc. due to the external short circuit due to bus bar dropping etc. Becomes higher.

In addition, since the strength of the assembled battery structure is reduced, external shock or vibration is applied to the assembled battery, the outer case may be broken, or the assembled battery may fall off. The possibility that the installed device will not function increases. Moreover, in order to reduce the variation in the dimensions of the prismatic battery, a part of the insulating film can be deleted. However, in this case, the metal can is exposed. For this reason, during the assembly work of the assembled battery, there is an increased risk that the prismatic battery will generate heat or ignite due to an external short circuit of the prismatic battery.
The present invention has been made in view of the above points, and an object of the present invention is to provide an assembled battery that can fix a rectangular battery satisfactorily and improve manufacturing yield and manufacturing efficiency.

In order to solve the above problems, an assembled battery according to an aspect of the present invention is provided.
A plurality of prismatic batteries each having a metal can, and an insulating exterior body covering the metal can,
A first support member and a second support member that is disposed to face the first support member with the plurality of prismatic batteries interposed therebetween, and that forms a plurality of fixing portions that fix the plurality of prismatic batteries together with the first support member. And a case having
Each fixing portion includes a first contact portion provided on the first support member and in contact with a corner portion of each square battery, and another corner provided on the second support member and facing the corner portion of the square battery. A second contact part in contact with the part,
The first contact portion includes a first protrusion that contacts a first surface that defines a corner of the prismatic battery, and a second protrusion that contacts the second surface that defines the corner together with the first surface. ,
The second contact portion includes a first protrusion that contacts a first surface that defines another corner facing the corner of the prismatic battery, and a second surface that defines the other corner together with the first surface. A second protrusion in contact,
Each first surface of the prismatic battery is longer than each second surface in a planar direction in which the corners of the prismatic battery and other corners face each other,
The first protrusion of the first contact portion contacts the first surface within a range of 22% of the length of the first surface from the corner, and at least a part of the first protrusion is measured from the corner. Contacting the first surface within a range of 17% to 22% of the length;
The first protrusion of the second contact portion contacts the first surface within a range of 22% of the length of the first surface from the other corner, and at least a part of the first protrusion is measured from the other corner. The first surface is in contact within a range of 17% to 22% of the length of the first surface.

  According to the present invention, it is possible to provide an assembled battery that can fix a rectangular battery satisfactorily and can improve manufacturing yield and manufacturing efficiency.

It is a disassembled perspective view which shows the assembled battery which concerns on embodiment of this invention. It is a perspective view which shows the square battery shown in FIG. It is an expansion perspective view which shows a part of said assembled battery, and is a figure which shows the state which the protrusion of a 1st contact part and the protrusion of a 2nd contact part are contacting the square battery especially. It is the figure which showed the deformation | transformation amount of the side surface with respect to the position of the side surface of the said square battery, and the deformation rate of the side surface with the table | surface. It is the figure which showed the deformation | transformation rate of the side surface with respect to the position of the side surface of the said square battery. It is sectional drawing which shows the modification of the assembled battery which concerns on the said embodiment. It is a disassembled perspective view of the assembled battery shown in FIG. FIG. 7 is another exploded perspective view of the assembled battery shown in FIG. 6.

Hereinafter, an assembled battery according to an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 1 to 3, the assembled battery includes a plurality of prismatic batteries 1 and a case 2.

  The square battery 1 is a secondary battery and is formed in a flat rectangular shape. The prismatic battery 1 is flat in a planar direction along the first direction d1 and the second direction d2 orthogonal to each other. Here, the assembled battery includes three prismatic batteries 1 arranged in a third direction d3 orthogonal to the first direction d1 and the second direction d2. The plurality of prismatic batteries 1 are located at a distance from each other.

  Each prismatic battery 1 includes a flat rectangular metal can 11 and an insulating film 12 as an insulating outer package that covers the metal can 11. The metal can 11 is made of aluminum, for example. Although not shown, the square battery 1 is formed by sealing an electrode group having both positive and negative electrodes and a non-aqueous electrolyte inside a metal can 11.

  In the planar direction, the prismatic battery 1 includes a bottom surface B facing the first direction d1, a side surface S facing the second direction d2, and four corners A1, A2 defined by the bottom surface B and the side surface S. A3 and A4 are included. In this embodiment, the side surface S is the first surface, the bottom surface B is the second surface, and the side surface S is longer than the bottom surface B. The prismatic battery 1 further includes a positive electrode terminal 13 and a negative electrode terminal 14 that are detached from the insulating film 12 and exposed outside the bottom surface B. Let L be the length of the side surface S in the planar direction (first direction d1). In this embodiment, L = 90 mm.

  The case 2 has a first support member 20 and a second support member 30. As a material for forming the first support member 20 and the second support member 30, for example, a synthetic resin such as PP (polypropylene) or PC (polycarbonate) can be used. The first support member 20 and the second support member 30 are disposed to face each other with the plurality of prismatic batteries 1 interposed therebetween. The first support member 20 and the second support member 30 are fixed to each other with screws, an adhesive, an adhesive tape, or the like.

  The first support member 20 includes a first support member main body 21, a protrusion 22 that protrudes from the first support member main body 21 and faces the side surface S of the prismatic battery 1, and protrudes from the first support member main body 21 in the third direction d3. And a plurality of protrusions 23 (all not shown) facing the prismatic battery 1. The first support member main body 21 is formed with a plurality of openings exposing the positive and negative bipolar terminals 13 and 14.

  The second support member 30 includes a second support member main body 31, a protrusion 32 that protrudes from the second support member main body 31 and faces the side surface S of the prismatic battery 1, and protrudes from the second support member main body 31 in the third direction d3. And a plurality of protrusions 33 facing the prismatic battery 1. In addition, the protrusion part 23 and the protrusion part 33 regulate the shift | offset | difference of the 3rd direction d3 of the square battery 1. FIG.

  The first support member 20 and the second support member 30 form a plurality of fixing portions 50 that fix the plurality of prismatic batteries 1. Each fixing portion 50 includes a first contact portion 60 and a second contact portion 70. The first contact portion 60 is provided on the first support member 20 and is in contact with the corner portion of each square battery 1. The second contact portion 70 is provided on the second support member 30 and is in contact with another corner portion facing the corner portion of the prismatic battery 1.

  The first contact portion 60 includes a protrusion 61 that contacts the side surface S that defines the corner A1 of the prismatic battery 1 and a protrusion 62 that contacts the bottom surface B that defines the corner A1 together with the side surface S. In this embodiment, the protrusion 61 is a first protrusion and the protrusion 62 is a second protrusion. The protrusion 61 is provided on the protrusion 22, and the protrusion 62 is provided on the first support member main body 21.

The second contact portion 70 includes a protrusion 71 that contacts the side surface S that defines the other corner A2 facing the corner A1 of the prismatic battery 1, and a protrusion 72 that contacts the bottom surface B that defines the corner A2 together with the side surface S. , Including. In this embodiment, the protrusion 71 is a first protrusion, and the protrusion 72 is a second protrusion. The protrusion 71 is provided on the protrusion 32, and the protrusion 72 is provided on the second support member main body 31.
The positive and negative bipolar terminals 13 and 14 of the plurality of prismatic batteries 1 are respectively connected by bus bars (not shown).

Here, in the planar direction (first direction d1) of the prismatic battery 1, 17% of the length of the side surface S is 17% L, and 22% of the length of the side surface S is 22% L.
The projection 61 of the first contact portion 60 contacts the side surface S within a range of 22% of the length of the side surface S from the corner A1, and at least a part of the projection 61 is 17 of the length of the side surface S measured from the corner A1. It is in contact with the side surface S within a range of% to 22%. The projection 71 of the second contact portion 70 contacts the side surface S within a range of 22% of the length of the side surface S from the corner A2, and at least a part of the projection 71 is 17 of the length of the side surface S measured from the corner A2. It is in contact with the side surface S within a range of% to 22%.

In other words, the protrusion 61 of the first contact portion 60 contacts the side surface S within the range of the angle A1 to 22% L, and at least a part of the protrusion 61 is measured from the angle A1 to 17% L to 22%. It is in contact with the side surface S within the range of L. The protrusion 71 of the second contact portion 70 contacts the side surface S within the range of 22% L from the angle A2, and at least a part of the protrusion 71 is measured within the range of 17% L to 22% L as measured from the angle A2. S is touching.
The protrusion 61 and the protrusion 71 are in contact with the insulating film 12, and the protrusion 62 and the protrusion 72 are in contact with the metal can 11.

  Here, the inventors of the present application investigated changes in the deformation amount of the side surface S in the second direction d2 with respect to the position of the side surface S of the square battery 1. When investigating, the deformation amount was investigated at a plurality of locations from one end (corner A1; 0 mm) to the other end (corner A4; 90 mm) of the side surface S of the square battery 1. As a result of the investigation, the deformation amount from the center of the side surface S toward the one end and the deformation amount toward the other end were almost the same. For this reason, hereinafter, the investigation result of the deformation amount of the side surface S in the range from one end to the center of the side surface S of the square battery 1 is shown, and the deformation rate of the side surface S calculated based on the deformation amount is also shown.

FIG. 4 is a table showing the position of the side surface S, the deformation amount of the side surface S, and the deformation rate of the side surface S investigated in the range from one end to the center of the side surface S of the square battery 1.
As shown in the figure, the amount of deformation at the position of the side surface S of 0 mm (one end of the side surface S; corner A1) measured from the corner A1 was 0.299 mm. The deformation rate at the 0 mm position was 100%.
The amount of deformation at the position of the side surface S of 5 mm measured from the angle A1 was 0.886 mm. The deformation rate at a position of 5 mm was calculated to be 296%.

The amount of deformation at the position of the side surface S of 10 mm measured from the angle A1 was 1.16 mm. The deformation rate at a position of 10 mm was calculated to be 387%.
The amount of deformation at the position of the side surface S of 15 mm measured from the angle A1 was 1.27 mm. When the deformation rate at a position of 15 mm was calculated, it was 425%.

The deformation amount at the position of the side surface S of 30 mm measured from the angle A1 was 1.38 mm. The deformation rate at a position of 30 mm was calculated to be 461%.
The amount of deformation at the position of the side surface S of 45 mm (center of the side surface S) measured from the angle A1 was 1.46 mm. The deformation rate at a position of 45 mm was calculated to be 488%.

FIG. 5 is a graph showing a change in the deformation rate of the side surface S with respect to the position of the side surface S investigated in the range from one end to the center of the side surface S of the square battery 1.
As can be seen from the figure, the deformation rate of the side surface S increases in the range of the side surface S measured from the angle A1 and exceeding 20 mm. For this reason, the protrusion 61 is preferably in contact with the side surface S within a range of 20 mm from the angle A1.

  Further, the deformation rate of the side surface S is not stable in the range of the side surface S measured from the angle A1 and less than or equal to 0 mm and less than 15 mm. For this reason, at least a part of the protrusion 61 is preferably in contact with the side surface S within a range of 15 mm to 20 mm as measured from the angle A1.

  In other words, the protrusion 61 contacts the side surface S within the range of the angle A1 to 22% L, and at least a part of the protrusion 61 is measured from the angle A1 and the side surface S within the range of 17% L to 22% L. It is preferable that it contacts. As with the protrusion 61, the protrusion 71 is preferably in contact with the side surface S that defines the angle A2.

  Further, the inventors of the present application investigated changes in the deformation amount of the bottom surface B in the first direction d1 with respect to the position of the bottom surface B of the square battery 1. As a result of the investigation, the deformation amount of the bottom surface B was constant throughout the entire region and was slight.

  According to the assembled battery configured as described above, the assembled battery includes a plurality of prismatic batteries 1 and a case 2. The case 2 includes a first support member 20 and a second support member 30 that forms a plurality of fixing portions 50 that fix the plurality of prismatic batteries 1 together with the first support member 20. Each fixing portion includes a first contact portion 60 that contacts a corner portion of each square battery 1 and a second contact portion 70 that contacts another corner portion of the square battery 1. The first contact part 60 includes a protrusion 61 and a protrusion 62, and the second contact part 70 includes a protrusion 71 and a protrusion 72.

  The protrusion 61 is in contact with the side surface S within the range of the angle A1 to 22% L, and at least a part thereof is in contact with the side surface S within the range of 17% L to 22% L as measured from the angle A1. The protrusion 71 is in contact with the side surface S within a range of 22% L from the corner A2, and at least a part is in contact with the side surface S within a range of 17% L to 22% L as measured from the corner A2.

  The case 2 is of a type that is fixed by sandwiching a pair of corners of each square battery 1. For this reason, in the case of a type having an insertion slot into which the prismatic battery 1 is inserted, it is possible to prevent the occurrence of problems such as turning, which have occurred in the insulating film 12.

  Each square battery 1 is firmly fixed by the case 2, particularly the protrusion 61, the protrusion 62, the protrusion 71 and the protrusion 72 without rattling. Even if an external impact or vibration is applied to the assembled battery, inappropriate force applied to the bus bar mounting part and the positive and negative bipolar terminals is reduced compared to the conventional assembled battery, thus preventing the bus bar from falling off. It is possible to avoid the risk of heat generation and ignition due to an external short circuit caused by the bus bar falling off.

  The strength of the assembled battery as a structure is higher than that of a conventional assembled battery. For this reason, when external impact or vibration is applied to the assembled battery, it is possible to reduce the occurrence of defects such as cracks that occur in the case 2, the risk that the assembled battery may fall off, and the device in which the assembled battery is installed The risk of not functioning can be avoided.

  The contact area of the case 2 with each square battery 1 is slightly smaller than that of a conventional assembled battery. In particular, the protrusion 61 and the protrusion 71 do not have a high deformation rate and are in contact with the side surface S in a range where the deformation rate is stable.

  Thereby, the square battery 1 can be satisfactorily fixed without rattling the square battery 1 without deleting the insulating film 12 where the protrusion 61 and the protrusion 71 are in contact. For this reason, during the assembly work of the assembled battery, it is possible to further avoid the risk of heat generation and ignition in the rectangular battery due to the external short circuit of the rectangular battery 1.

Moreover, since the contact area of the case 2 with respect to the insulating film 12 of each square battery 1 can be reduced, the turn-up of the insulating film 12 can be reduced during the assembly work of the assembled battery. And even if the insulating film 12 is wound around the whole square battery 1, the dispersion | variation in the dimension of the square battery 1 can be absorbed easily.
From the above, it is possible to obtain an assembled battery that can fix the rectangular battery well and improve the manufacturing yield and manufacturing efficiency.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment.

For example, the assembled battery may include two or four or more prismatic batteries 1.
As shown in FIGS. 6 to 8, the assembled battery may include twelve prismatic batteries 1. Four square batteries 1 are arranged in the second direction d2 and three in the third direction d3, and are spaced apart from each other. The first support member 20 and the second support member 30 are disposed to face each other with all twelve prismatic batteries 1 interposed therebetween.

  The first support member 20 includes a first support member main body 21, a plurality of protrusions 22, and a plurality of protrusions 23. The second support member 30 includes a second support member main body 31, a plurality of protrusions 32, and a plurality of protrusions 33. The plurality of protrusions 22 and the plurality of protrusions 32 are arranged alternately in the second direction d2. In addition to the above, the assembled battery shown in FIGS. 6 to 8 is formed in the same manner as the assembled battery of the above embodiment. Even if the assembled battery is configured as described above, the same effects as those of the above-described embodiment can be obtained.

  The case 2 has two support members, the first support member 20 and the second support member 30, but is not limited to this, and may have two or more members (support members). The above-described effects can be obtained.

  Each fixing portion 50 may further include at least one of a third contact portion and a fourth contact portion that are in contact with the other two corner portions positioned in the planar direction of the prismatic battery 1. For example, when each fixing part 50 includes a first contact part 60, a second contact part 70, a third contact part, and a fourth contact part, the fixing part 50 defines these contact parts as a plane of the rectangular battery 1. What is necessary is just to contact all the corner | angular parts located in the direction, and to fix a square battery.

  In the prismatic battery 1, the bottom surface B may be longer than the side surface S. In this case, the side surface S is the second surface, the bottom surface B is the first surface, the protrusion 62 and the protrusion 72 are each the first protrusion, and the protrusion 61 and the protrusion 71 are each the second protrusion.

  In the above case, the protrusion 62 of the first contact portion 60 contacts the bottom surface B within a range of 22% of the length of the bottom surface B from the corner A1, and at least a part of the protrusion 62 is measured from the corner A1 and measured on the bottom surface B. The projection 72 of the second contact portion 70 contacts the bottom surface B within the range of 22% of the length from the corner A2 to the bottom surface B within the range of 17% to 22% of the length, and the projection Since at least a part of 72 is in contact with the bottom surface B within a range of 17% to 22% of the length of the bottom surface B as measured from the angle A2, the above-described effect can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Square-shaped battery, 2 ... Case, 11 ... Metal can, 12 ... Insulating film, 13 ... Positive electrode terminal, 14 ... Negative electrode terminal, 20 ... 1st support member, 21 ... 1st support member main body, 22, 23 ... Projection , 30 ... second support member, 31 ... second support member main body, 32, 33 ... projecting part, 50 ... fixing part, 60 ... first contact part, 61, 62 ... projection, 70 ... second contact part, 71 72, projections, A1, A2, A3, A4, corners, B, bottom surfaces, S, side surfaces.

Claims (4)

A plurality of prismatic batteries each having a metal can, and an insulating exterior body covering the metal can,
A first support member and a second support member that is disposed to face the first support member with the plurality of prismatic batteries interposed therebetween, and that forms a plurality of fixing portions that fix the plurality of prismatic batteries together with the first support member. And a case having
Each fixing portion includes a first contact portion provided on the first support member and in contact with a corner portion of each square battery, and another corner provided on the second support member and facing the corner portion of the square battery. A second contact part in contact with the part,
The first contact portion includes a first protrusion that contacts a first surface that defines a corner of the prismatic battery, and a second protrusion that contacts the second surface that defines the corner together with the first surface. ,
The second contact portion includes a first protrusion that contacts a first surface that defines another corner facing the corner of the prismatic battery, and a second surface that defines the other corner together with the first surface. A second protrusion in contact,
Each first surface of the prismatic battery is longer than each second surface in a planar direction in which the corners of the prismatic battery and other corners face each other,
The first protrusion of the first contact portion contacts the first surface within a range of 22% of the length of the first surface from the corner, and at least a part of the first protrusion is measured from the corner. Contacting the first surface within a range of 17% to 22% of the length;
The first protrusion of the second contact portion contacts the first surface within a range of 22% of the length of the first surface from the other corner, and at least a part of the first protrusion is measured from the other corner. An assembled battery in contact with the first surface within a range of 17% to 22% of the length of the first surface. The prismatic battery further includes positive and negative bipolar terminals that are detached from the insulating outer casing and exposed outside the second surface defining the corner,
The first support member is opposed to a second surface defining the corner of the prismatic battery, and the second support member is opposed to a second surface defining the other corner of the prismatic battery. Item 4. The assembled battery according to Item 1. The first support member includes a first support member main body, and a plurality of first protrusions of the plurality of first contact portions that protrude from the first support member main body and face the first surface of the prismatic battery. A plurality of protrusions,
The second support member includes a second support member main body, and a plurality of first protrusions of the plurality of second contact portions that protrude from the second support member main body and face the first surface of the prismatic battery. A plurality of other protrusions,
The assembled battery according to claim 1, wherein the plurality of protrusions and the plurality of other protrusions are arranged alternately.   The fixing portion further includes a third contact portion and a fourth contact portion that are in contact with the other two corner portions located in the planar direction of the square battery, and together with the first contact portion and the second contact portion, The assembled battery according to claim 1, wherein a square battery is fixed.

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