JP2015022843A - Electricity storage device module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electricity storage device module capable of effectively utilizing a spacer.SOLUTION: A battery module 70 includes a plurality of secondary batteries 10, and each of the secondary batteries 10 includes a short circuit unit 30, and a metal spacer 50 thermally coupled to the short circuit unit 30. A thickness of the spacer 50 is set according to the length of a space S along the lamination direction of an electrode assembly 14. A spacer 50 included in each of secondary batteries 10 disposed at both ends in the direction of side-by-side arrangement, among the plurality of secondary batteries 10 has a thickness thicker than that of each spacer 50 included in other secondary batteries 10.

Description

  The present invention relates to a power storage device module including a plurality of power storage devices in which a short-circuit unit and a spacer are arranged in a gap between a flat surface of an electrode assembly and a wall portion of a case.

  Vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) are equipped with battery modules as power storage device modules that store power supplied to motors that serve as prime movers. The battery module is configured by juxtaposing a plurality of secondary batteries as power storage devices in a state of being electrically connected by a conductive member.

  Further, in each secondary battery constituting the battery module, a spacer is inserted in a gap between both end surfaces in the stacking direction of the electrode assembly housed in the case and the wall portion of the case facing each end surface. (For example, refer to Patent Document 1). In Patent Document 1, the thickness of each secondary battery is made constant in a state where the secondary batteries are constrained in the juxtaposition direction by a spacer inserted in a gap between the secondary batteries.

JP 2008-108457 A

  However, as in Patent Document 1, in a secondary battery in which a spacer is inserted into a gap generated in the case, the space occupied by the spacer in the case is a dead space that does not contribute to the function of the secondary battery such as power storage. It has become.

  An object of the present invention is to provide a power storage device module that can effectively use a spacer.

  In order to solve the above-described problem, the power storage device module includes a case where an electrode assembly in which a positive electrode and a negative electrode are stacked in layers with a separator interposed therebetween is housed in a case, and the stacking direction of the electrode assemblies A plurality of power storage devices in which a short-circuit unit and a metal spacer thermally coupled to the short-circuit unit are disposed in a gap between the flat surface located at least one end of the case and the wall of the case facing the flat surface A plurality of power storage devices arranged side by side in a state in which the wall portions are arranged in one direction, and the thickness of the spacer is set according to the length of the gap along the stacking direction. Among the devices, the gist of the spacers included in the power storage devices arranged at both ends in the juxtaposed direction is thicker than the spacers included in other power storage devices.

  According to this, when the external force applied from the end portion side in the parallel arrangement direction of the power storage devices acts on the short-circuit unit and the short-circuit unit is short-circuited, the short-circuit unit generates heat. At this time, if the spacer is thermally coupled to the short-circuit unit, the heat generated in the short-circuit unit can be released to the spacer. For this reason, the temperature of a short circuit unit can be lowered | hung and the damage by the heat | fever of the electrode assembly adjacent to a short circuit unit can be suppressed. The power storage devices at both ends of the power storage device module in the juxtaposed direction are at positions most susceptible to external force, but since the spacer is thick, the amount of heat that can be released to the spacer is large, and damage to the electrode assembly can be suppressed. . In addition, the external force is directly applied to the power storage devices at both ends in the side-by-side direction. However, since the spacer is thicker than the spacers of the other power storage devices, the external force can be received by the spacer and the impact of the electrode assembly can be reduced. Therefore, even if the spacer is inserted into the gap formed in the case, the spacer can be used effectively, and the space occupied by the spacer in the case does not become a dead space.

In the power storage device module, it is preferable that an electrolyte is accommodated in the case and the spacer is made of aluminum.
According to this, it can prevent that a spacer melt | dissolves with electrolyte solution.

In the power storage device, the spacer is preferably a single metal plate having a thickness that matches the length of the gap.
According to this, when one spacer is used, heat is quickly transmitted to the entire spacer, and there is no possibility that heat transfer is hindered by a gap between the metal foils, for example, when a plurality of metal foils are laminated. Therefore, the heat generated in the short-circuit unit can be quickly released to the spacer.

  In the power storage device module, the power storage device is a secondary battery.

  According to the present invention, the spacer can be effectively used.

The perspective view which shows a battery module. The disassembled perspective view which shows a secondary battery. The disassembled perspective view which shows the component in a secondary battery. The disassembled perspective view which shows a battery module. Sectional drawing which shows the inside of a battery module.

Hereinafter, an embodiment in which a power storage device module is embodied as a battery module will be described with reference to FIGS.
As shown in FIG. 1, the battery module 70 is configured by arranging a plurality of secondary batteries 10 held in a battery holder 60 side by side in the thickness direction (one direction).

First, the secondary battery 10 will be described.
As shown in FIGS. 2 and 4, the secondary battery 10 is configured such that an electrode assembly 14 and an electrolytic solution are accommodated in a rectangular box-like case 11. The case 11 includes a bottomed square box-like case body 12 and a flat lid 13 that closes an opening for inserting the electrode assembly 14 into the case body 12. Both the case main body 12 and the lid body 13 are made of metal (for example, stainless steel or aluminum). In addition, the secondary battery 10 is a rectangular battery having a rectangular outer shape because the case body 12 has a bottomed square box shape and the lid 13 has a rectangular flat plate shape. Moreover, the secondary battery 10 of this embodiment is a lithium ion battery.

  The case body 12 includes a rectangular bottom plate 12a, a pair of short side walls 12b erected from the short side edge of the bottom plate 12a, and a pair of long side walls 12c erected from the long side edge of the bottom plate 12a. In the case 11, the open ends of the short side wall 12 b and the long side wall 12 c are joined to the lid body 13.

  As shown in FIG. 3, the electrode assembly 14 is configured by laminating a plurality of positive electrodes 21 and a plurality of negative electrodes 24 with a separator 27 interposed therebetween. The positive electrode 21 includes a rectangular positive electrode metal foil (in this embodiment, an aluminum foil) 22 and a rectangular positive electrode active material layer 23 provided on both surfaces (surfaces) of the positive electrode metal foil 22. Have. The positive electrode 21 has a positive electrode-side uncoated portion 22d along which the positive electrode active material layer 23 is not provided. And in the positive electrode 21, the positive electrode current collection tab 22f is provided in the state which protrudes in a part of one side of the positive electrode side uncoated part 22d.

  The negative electrode 24 includes a rectangular negative electrode metal foil (copper foil in this embodiment) 25 and a rectangular negative electrode active material layer 26 provided on both surfaces (surfaces) of the negative electrode metal foil 25. Have. The negative electrode 24 has a negative electrode-side uncoated portion 25d along which the negative electrode active material layer 26 is not provided. And in the negative electrode 24, the negative electrode current collection tab 25f protrudes in a part of one side of the negative electrode side uncoated part 25d. The number of the negative electrode 24 is one more than that of the positive electrode 21, and the negative electrode 24 is disposed at both ends of the electrode assembly 14.

  As shown in FIG. 2, the positive electrode 21 and the negative electrode 24 are arranged such that the positive electrode current collecting tabs 22f are arranged in a line along the stacking direction and do not overlap the positive electrode current collecting tabs 22f. Are stacked in a row along the stacking direction. Each positive electrode current collecting tab 22f is bent in a state of being collected (bundled) within a range from one end to the other end of the electrode assembly 14 in the stacking direction. Each positive current collecting tab 22f is electrically connected by welding a portion where each positive current collecting tab 22f overlaps, and the positive terminal 16 is connected to the positive current collecting tab 22f. Each negative electrode current collecting tab 25f is electrically connected by welding the location where each negative electrode current collecting tab 25f overlaps, and the negative electrode terminal 17 is connected to the negative electrode current collecting tab 25f. The positive electrode terminal 16 and the negative electrode terminal 17 penetrate the lid body 13 and protrude outside the case 11. The positive terminal 16 and the negative terminal 17 are insulated from the lid 13 by an insulating ring 15.

  As shown in FIGS. 2 and 5, in the electrode assembly 14, between the flat surfaces 14a at both ends in the stacking direction and the inner surfaces 12d of the long side walls 12c of the case body 12 facing both the flat surfaces 14a, A spacer 50 and a short-circuit unit 30 are interposed. Therefore, in this embodiment, the long side wall 12c constitutes the wall portion of the case 11 that faces the flat surface 14a.

  The short-circuit unit 30 includes a rectangular and aluminum foil first metal member 31, a rectangular insulating member 32, and a rectangular and copper foil second metal member 33. The first metal member 31, the insulating member 32, and the second metal member 33 are stacked from the long side wall 12 c toward the electrode assembly 14.

  The first metal member 31 includes a rectangular first main body portion 31 a that faces the second metal member 33 with the insulating member 32 interposed therebetween, and a first tab portion 31 b that does not face the second metal member 33. That is, the 1st tab part 31b is provided in the state which protrudes from a part of one side of the 1st main-body part 31a.

  The second metal member 33 includes a rectangular second main body portion 33 a that faces the first metal member 31 with the insulating member 32 interposed therebetween, and a second tab portion 33 b that does not face the first metal member 31. The 2nd tab part 33b is provided in the state which protrudes from a part of one side of the 2nd main-body part 33a.

  In the short-circuit unit 30, the second main body portion 33 a of the second metal member 33 is in surface contact with the flat surface 14 a of the electrode assembly 14. The first metal member 31 can be the same shape as the positive electrode metal foil 22 of the positive electrode 21 in the electrode assembly 14, and the second metal member 33 can be the negative electrode 24 in the electrode assembly 14. The same shape as that of the negative electrode metal foil 25 can be used.

  And the 1st metal member 31 in the short circuit unit 30 has the 1st tab part 31b electrically connected with the positive electrode current collection tab 22f of the electrode assembly 14, and has become a positive electrode. On the other hand, the second tab 33b of the second metal member 33 is electrically connected to the negative electrode current collecting tab 25f of the electrode assembly 14 to be a negative electrode. The short-circuit unit 30 is configured by stacking a first metal member 31, an insulating member 32, and a second metal member 33, and the first metal member 31, the insulating member 32, and the second metal member 33 are also included in the electrode assembly 14. They are stacked along the stacking direction.

Next, the spacer 50 will be described.
The spacer 50 is preferably a metal material that has a large thermal conductivity and a large heat capacity and is difficult to dissolve in the electrolytic solution. In this embodiment, the spacer 50 is made of aluminum. The spacer 50 has a rectangular plate shape, and its planar shape is smaller than the planar shape of the long side wall 12 c and is substantially the same as the flat surface 14 a of the electrode assembly 14. Each spacer 50 has two side surfaces 50a and 50b having the largest area, one side surface 50a is in contact with the first metal member 31 in the short-circuit unit 30, and the other side surface 50b is the inner surface 12d of the long side wall 12c. In contact with. The spacer 50 and the short-circuit unit 30 are disposed on both sides of the electrode assembly 14 in the stacking direction, and the movement of the electrode assembly 14 in the case 11 along the stacking direction is regulated by both the spacers 50. At the same time, it is constrained in the stacking direction.

  In the battery module 70, the number of used positive electrode 21, negative electrode 24, and separator 27 constituting the electrode assembly 14 is the same in all the secondary batteries 10, but the thickness of each of the active material layers 23 and 26 is the same. The length in the stacking direction differs depending on the difference. The length of the gap S between the flat surface 14a of the electrode assembly 14 and the inner surface 12d of the opposing long side wall 12c is different. For this reason, the thickness of the spacer 50 interposed in the gap S is also different for each secondary battery 10. The thickness of the spacer 50 is the length along the stacking direction of the electrode assembly 14.

  As shown in FIG. 4, the battery holder 60 that holds the secondary battery 10 includes a holder main body 61 that has a U-shaped frame shape and rectangular parallelepiped leg portions 62 that protrude from four corners of the outer surface of the holder main body 61. doing. The holder body 61 is integrated with the secondary battery 10 so as to surround the bottom plate 12 a of the case 11, the pair of short side walls 12 b, and both the short side walls 12 b of the lid 13. For this reason, in the secondary battery 10 integrated with the battery holder 60, the pair of long side walls 12 c are exposed to the outside from the holder body 61. Each leg portion 62 is provided with an insertion hole 62a through which the bolt B1 is inserted, penetrating in the longitudinal direction of the leg portion 62.

  As shown in FIGS. 1 and 5, end plates 53 are provided at both ends of the battery modules 70 in the juxtaposition direction. The end plate 53 includes a base portion 54 having a rectangular flat plate shape and a rectangular flat plate-like protruding portion 55 protruding from the four corners of the base portion 54. The protruding portion 55 is provided with an insertion hole 55 a through which the bolt B <b> 1 is inserted so as to penetrate in the thickness direction of the protruding portion 55.

  In the battery module 70, the bolt B <b> 1 inserted into the insertion hole 55 a of one end plate 53 is inserted into the insertion hole 62 a of each battery holder 60 and also inserted into the insertion hole 55 a of the other end plate 53. The nut N is screwed together with the bolt B1 so as to be integrally assembled. Therefore, all the secondary batteries 10 are sandwiched between the end plates 53 from the juxtaposed direction. In the battery module 70, the plurality of secondary batteries 10 are arranged side by side with the long side walls 12c aligned in one direction.

  In the battery module 70, a heat radiating plate 71 and a heat transfer sheet 80 are interposed between the long side walls 12 c of the secondary batteries 10 adjacent to each other in the juxtaposed direction. Further, a heat radiating plate 71 and a heat transfer sheet 80 are also interposed between the end plate 53 and the long side wall 12 c of the secondary battery 10 adjacent to the end plate 53.

  As shown in FIG. 5, in the battery module 70 in which a plurality of the secondary batteries 10 having the above-described configuration are arranged in parallel, the secondary batteries 10 arranged at one end in the arrangement direction are electrodes among all the secondary batteries 10. The length of the assembly 14 in the stacking direction is the shortest. In the battery module 70, the secondary battery 10 disposed at the other end in the juxtaposed direction has the second shortest length in the stacking direction of the electrode assembly 14 among all the secondary batteries 10. Yes. For this reason, in the secondary battery 10 arranged at one end in the juxtaposed direction, the gap S on both sides in the stacking direction of the electrode assembly 14 is the longest among all the secondary batteries 10 and the other end in the juxtaposed direction. As for the secondary battery 10 arrange | positioned, the clearance gap S of the lamination direction both sides of the electrode assembly 14 is the 2nd long in all the secondary batteries 10. FIG.

  The secondary battery 10 having the thickest spacer 50 among all the secondary batteries 10 is arranged at one end in the juxtaposed direction, and all the secondary batteries 10 are arranged at the other end in the juxtaposed direction. Among the secondary batteries 10, the secondary battery 10 including the second thickest spacer 50 is disposed. In addition, the secondary batteries 10 in the central portion in the juxtaposed direction have the longest length in the stacking direction of the electrode assemblies 14 and the shortest gap S among all the secondary batteries 10. For this reason, the secondary battery 10 provided with the thinnest spacer 50 among all the secondary batteries 10 is arranged in the central portion in the juxtaposed direction. And the thickness of the spacer 50 is gradually reduced as it goes to the center part from both ends in the juxtaposed direction. That is, the spacer 50 of the secondary battery 10 disposed on both ends from the center is thicker.

Next, the operation of the battery module 70 will be described by taking a nail penetration test which is one of evaluation tests of the secondary battery 10 as an example.
When a nail is pierced into the secondary battery 10 at one end of the both ends of the battery modules 70 in the side-by-side arrangement, the nail penetrates the spacer 50 and the first main body 31a and the insulating member 32 of the first metal member 31. Break through. Thereby, the first metal member 31 and the second metal member 33 are electrically connected to each other and short-circuited, and electricity stored in the electrode assembly 14 of the secondary battery 10 is discharged in the short-circuit unit 30. . In the short-circuit unit 30, heat is generated by a short circuit between the first metal member 31 and the second metal member 33, but the heat is transmitted to the spacer 50, and the temperature rise of the first metal member 31 and the second metal member 33 is suppressed. An increase in the temperature of the electrode assembly 14 is also suppressed.

According to the above embodiment, the following effects can be obtained.
(1) In the battery module 70, the thickness of the spacer 50 provided in the secondary battery 10 disposed at both ends in the juxtaposed direction is made thicker than the thickness of the spacer 50 provided in the other secondary battery 10. For this reason, the heat generated when the short-circuit unit 30 is short-circuited can be released to the spacer 50, and the temperature rise of the short-circuit portion and the electrode assembly 14 adjacent to the short-circuit portion is suppressed. And since the spacer 50 with which the secondary battery 10 of the both ends of a parallel arrangement direction is thicker than the spacer 50 with which the other secondary battery 10 is provided, the heat capacity is also large and the amount of heat which can be released to the spacer 50 is also other than that. More than the spacer 50. Therefore, it is effective in suppressing the temperature rise of the electrode assembly 14 adjacent to the short-circuit unit 30.

  (2) The external force is directly applied to the secondary batteries 10 at both ends in the juxtaposed direction. In the secondary batteries 10 arranged at both ends in the parallel arrangement direction, the spacer is thicker than the spacers 50 of the other secondary batteries 10, so that the external force can be received by the spacer 50, and the impact received by the electrode assembly 14 is received. Can be relaxed. Therefore, even if the spacer 50 is inserted into the gap S formed in the case 11, the spacer 50 can be used effectively, and the space occupied by the spacer 50 in the case 11 does not become a dead space.

  (3) Since the spacer 50 is made of aluminum, it is possible to prevent the spacer 50 from being dissolved in the electrolytic solution. Therefore, the state in which the electrode assembly 14 is restrained in the stacking direction by the spacer 50 and the state in which the movement of the electrode assembly 14 is restricted can be maintained.

  (4) The spacer 50 is formed of a single metal plate. For this reason, for example, the heat capacity of the spacer 50 can be increased as compared with the case where a plurality of metal foils having a predetermined thickness are stacked, and heat transfer may be hindered by the gaps between the metal foils. Nor. Therefore, the heat generated in the short-circuit unit 30 can be quickly released to the spacer 50.

  (5) The spacer 50 is formed of a single metal plate. By preparing a plurality of types of spacers 50 having different thicknesses, it is possible to cope with a plurality of types of gaps S. Therefore, for example, compared with the case where the spacer 50 is formed by stacking metal foils, the thickness adjustment of the spacer 50 and the insertion operation of the spacer 50 into the gap S can be easily performed.

  (6) Since the spacer 50 and the first metal member 31 of the short-circuit unit 30 are in contact with each other and are conductive, the spacer 50 is thick when the short-circuit unit 30 is broken and short-circuited by a metal protrusion or the like. As a result, the contact area with the metal protrusion or the like is increased, and short circuit resistance, that is, Joule heat generated by short circuit can be suppressed.

In addition, you may change the said embodiment as follows.
The spacer 50 may be formed by laminating a plurality of aluminum foils or copper foils.
The battery module 70 may include the secondary battery 10 that does not include the spacer 50. Although the length in the stacking direction of the electrode assembly 14 varies depending on manufacturing tolerances, when the secondary battery 10 included in the battery module 70 is designed and manufactured with a minimum manufacturing tolerance of zero, The spacer 50 is not provided.

The material of the spacer 50 may be a copper plate, stainless steel, or may be changed as appropriate.
The thickness of the spacer 50 does not have to be reduced from both ends of the battery module 70 in the juxtaposed direction toward the center, and the spacer 50 provided in the secondary battery 10 arranged at both ends of the juxtaposed direction As long as it is thicker than the spacer 50 included in the secondary battery 10, the arrangement order of the other spacers 50 may be changed as appropriate.

  In the embodiment, in each secondary battery 10, the spacer 50 and the short-circuit unit 30 are interposed between the flat surfaces 14a on both sides in the stacking direction of the electrode assembly 14 and the long side walls 12c. However, the present invention is not limited to this. . For example, one flat surface 14a in the stacking direction of the electrode assembly 14 is brought into contact with one long side wall 12c, and the short-circuit unit 30 and the spacer 50 are interposed only between the other flat surface 14a and the other long side wall 12c. May be. In this case, the short-circuit unit 30 and the spacer 50 are disposed in the gap S on the end side in the juxtaposition direction with respect to the electrode assembly 14.

  ○ Among the plurality of secondary batteries 10 constituting the battery module 70, some of the secondary batteries 10 have the short-circuit units 30 and the spacers 50 interposed on both sides of the electrode assembly 14 in the stacking direction, and the remaining secondary batteries 10, the short-circuit unit 30 and the spacer 50 may be interposed only in one side of the electrode assembly 14 in the stacking direction.

  ○ The short-circuit unit 30 is configured by laminating the first metal member 31, the insulating member 32, and the second metal member 33 one by one, but the first metal member 31, the insulating member 32, and the second metal member 33 The number of stacked layers may be changed as appropriate.

The electrode assembly 14 is a laminated type, but may be a wound type in which a separator 27 is sandwiched between a positive electrode 21 and a negative electrode 24 and these are wound in layers.
The number of positive electrodes 21 and negative electrodes 24 constituting the electrode assembly 14 may be changed as appropriate.

  In the embodiment, the positive electrode 21 has the positive electrode active material layer 23 on both sides of the positive electrode metal foil 22, but has the positive electrode active material layer 23 only on one side of the positive electrode metal foil 22. Also good. Similarly, the negative electrode 24 has the negative electrode active material layer 26 on both sides of the negative electrode metal foil 25, but may have the negative electrode active material layer 26 only on one side of the negative electrode metal foil 25. .

O You may actualize as a nickel-hydrogen secondary battery as an electrical storage apparatus, or an electric double layer capacitor.
Next, the technical idea that can be grasped from the above embodiment and other examples will be described below.

  (A) The electrode assembly is a stacked type power storage device module.

  DESCRIPTION OF SYMBOLS S ... Gap, 10 ... Secondary battery as power storage device, 11 ... Case, 12c ... Long side wall as wall, 14 ... Electrode assembly, 14a ... Flat surface, 21 ... Positive electrode, 24 ... Negative electrode, 27 ... Separator, 30 ... short-circuit unit, 50 ... spacer, 70 ... battery module as power storage device module.

Claims (4)

The electrode assembly that overlaps in layers with the positive electrode and the negative electrode interposed between the separators is housed in the case,
In the gap between the flat surface located at least one end in the stacking direction of the electrode assembly and the wall portion of the case facing the flat surface, a short-circuit unit and a metal spacer thermally coupled to the short-circuit unit are provided. While including a plurality of arranged power storage devices,
A plurality of power storage devices are juxtaposed with the wall portions arranged in one direction,
The thickness of the spacer is set according to the length of the gap along the stacking direction,
Among the plurality of power storage devices, a power storage device module characterized in that a spacer included in a power storage device disposed at both ends in the juxtaposition direction is thicker than a spacer included in another power storage device.   The power storage device module according to claim 1, wherein an electrolytic solution is accommodated in the case, and the spacer is made of aluminum.   The power storage device module according to claim 1, wherein the spacer is a single metal plate having a thickness corresponding to the length of the gap.   The power storage device module according to any one of claims 1 to 3, wherein the power storage device is a secondary battery.