JP5292663B2 - Assembled battery and vehicle equipped with the assembled battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack allowing for improving the cooling efficiency of secondary cells. <P>SOLUTION: The battery pack is equipped with 8 sets of battery stacks 30a to 30h, with each being constituted of 10 stacked secondary cells; heat sinks 20 between which the secondary cells 10a to 10j are interposed; a case 40, in which the battery stacks 30a to 30h are disposed on the same plane and housed in an internal space 41 thereof; an inlet duct 50, communicating the exterior of the battery pack and the internal space 41 of the case 40; an outlet duct 60, communicating the internal space 41 of the case 40 and the exterior of the battery pack; and a fan 70 disposed in the outlet duct 60, wherein the cooling wind taken into the internal space 41 of the case 40 via the inlet duct 50 by negative pressure produced by the rotating drive of the fan 70 enters each passage formed in the heat sinks 20 and indirectly cools the secondary cells, and enters each flow channel formed between each battery stacks 30a to 30h and directly cools the secondary cells. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to an assembled battery configured by arranging two or more battery stacks in which a plurality of thin secondary batteries using a laminate film as an exterior member are stacked, and a vehicle equipped with the assembled battery.

  In order to secure a desired capacity and voltage, there has been conventionally known a technique for forming an assembled battery by arranging two or more battery stacks in which a plurality of thin secondary batteries using a laminate film as an exterior member are stacked in parallel on the same plane. (For example, refer to Patent Document 1).

In such an assembled battery, since the secondary battery constituting each battery stack generates heat as the battery is discharged, a heat sink is interposed between the secondary batteries to form the inside of the heat sink. By blowing cooling air through the passage, the secondary battery is indirectly cooled through the heat sink. However, if a sufficient cooling effect is ensured by such a method, the shape of the heat sink becomes complicated and the number of the heat sinks increases, resulting in an increase in cost of the assembled battery. On the other hand, if the shape of the heat sink is simply simplified or the number of sheets is reduced, the cooling efficiency of each secondary battery is deteriorated.
JP 2003-303583 A

An object of this invention is to provide the assembled battery which can improve the cooling efficiency of a secondary battery, and the vehicle carrying the said assembled battery.
To achieve the above object, according to the present invention, an electrode plate laminated via a separator is accommodated in an exterior member having a synthetic resin layer made of a synthetic resin material and a metal layer made of a metal material, A secondary battery in which the outer peripheral edge of the member is heat-sealed to form a heat-sealed portion to seal the electrode plate, and the electrode terminal connected to the electrode plate is led out from the outer peripheral edge of the exterior member. A battery pack including a plurality of stacked battery stacks, a coolant supply means for supplying a coolant for cooling the secondary battery, a case capable of housing the battery stack, and the coolant supply means A housing having an inlet side opening and an outlet side opening connected to each other, and housing the case , wherein the case is configured to introduce or supply the refrigerant supplied from the refrigerant supply means into the case. Multiple openings for discharging The refrigerant supplied from the refrigerant supply means is introduced into the case through the one opening, and the inner wall surface of the case and the battery stack are formed by the heat fusion part of the secondary battery. Passing through the flow path formed between the first and second cases, and is discharged from the case through the other opening. Around the opening of the case, the refrigerant supplied from the refrigerant supply means is opened to the opening. Provided are an assembled battery provided with an air scoop that is directed toward the portion , and a vehicle equipped with the assembled battery.

In the present invention, in a battery pack in which a case in which a battery stack in which a plurality of secondary batteries using a laminate film having a synthetic resin layer and a metal layer as an exterior member are stacked is housed is housed in a housing , the secondary battery is coolant supply means for supplying a coolant for cooling is provided, this by the refrigerant supply means, passing the refrigerant flow path formed between the inner wall and the cell stack of the case. Thereby, since a refrigerant | coolant contacts the exterior member of each secondary battery and it cools directly, each secondary battery which comprises an assembled battery can be cooled efficiently.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a plan view showing an entire secondary battery according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the secondary battery taken along line II-II in FIG.

  1 and 2 show one thin battery 10 (unit battery). A plurality of thin batteries 10 are stacked to form an assembled battery having a desired voltage and capacity.

  First, the secondary battery 10 according to the present embodiment will be described. This battery 10 is a lithium-based flat-type laminated thin battery, and as shown in FIGS. 1 and 2, three positive plates 101 and It is composed of five separators 102, three negative plates 103, a positive terminal 104, a negative terminal 105, an upper exterior member 106, a lower exterior member 107, and an electrolyte (not shown). Among these, the positive electrode plate 101, the separator 102, the negative electrode plate 103, and the electrolyte are particularly referred to as a power generation element 108.

  The positive electrode plate 101 constituting the power generation element 108 includes a positive electrode side current collector 101a extending to the positive electrode plate 104, and positive electrode layers 101b and 101c formed on both main surfaces of a part of the positive electrode side current collector 101a, respectively. ,have. In addition, the positive electrode layers 101b and 101c of the positive electrode plate 101 are not formed over both main surfaces of the entire positive electrode current collector 101a, but as shown in FIG. When the power generation element 108 is configured by laminating the negative electrode plate 103, the positive electrode layers 101 b and 101 c are formed only on the portion of the positive electrode plate 101 that substantially overlaps the separator 102.

  The positive electrode side current collector 101a of the positive electrode plate 101 is an electrochemically stable metal foil such as an aluminum foil, an aluminum alloy foil, a copper foil, or a nickel foil.

The positive electrode layers 101b and 101c of the positive electrode plate 101 are made of, for example, lithium composite oxide such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), or lithium cobaltate (LiCoO ₂ ), or chalcogen. A mixture of a positive electrode active material such as (S, Se, Te) compound, a conductive agent such as carbon black, and an adhesive such as an aqueous dispersion of polytetrafluoroethylene is used for the positive electrode side current collector 101a. It is formed by applying to some of both main surfaces, drying and rolling.

  The negative electrode plate 103 constituting the power generation element 108 includes a negative electrode side current collector 103a extending to the negative electrode terminal 105, and negative electrode layers 103b and 103c formed on both main surfaces of a part of the negative electrode side current collector 103a, respectively. And have. Note that the negative electrode layers 103b and 103c of the negative electrode plate 103 are not formed over both main surfaces of the entire negative electrode side current collector 103a, but as shown in FIG. When the power generation element 108 is configured by laminating the negative electrode plate 103, the negative electrode layers 103 b and 103 c are formed only on the portion of the negative electrode plate 103 that substantially overlaps the separator 102.

  The negative electrode side current collector 103a of the negative electrode plate 103 is an electrochemically stable metal foil such as nickel foil, copper foil, stainless steel foil, or iron foil.

  Further, the negative electrode layers 103b and 103c of the negative electrode plate 103 occlude and release lithium ions of the positive electrode active material such as amorphous carbon, non-graphitizable carbon, graphitizable carbon, or graphite. An aqueous dispersion of a styrene butadiene rubber resin powder as a precursor material of an organic fired body is mixed with the negative electrode active material, and dried and pulverized to support carbonized styrene butadiene rubber on the carbon particle surfaces. It is formed by mixing a binder, such as an acrylic resin emulsion, and applying this mixture to both main surfaces of part of the negative electrode side current collector 103a, followed by drying and rolling. Yes.

  In particular, when amorphous carbon or non-graphitizable carbon is used as the negative electrode active material, the flatness of the potential during charge / discharge is poor and the output voltage decreases with the amount of discharge. Although unsuitable, it is advantageous when used as a power source for an electric vehicle because there is no sudden drop in output.

  The separator 102 of the power generation element 108 prevents a short circuit between the positive electrode plate 101 and the negative electrode plate 103 described above, and may have a function of holding an electrolyte. This separator 102 is a microporous film made of polyolefin such as polyethylene (PE) or polypropylene (PP), for example. When an overcurrent flows, the pores of the layer are blocked by the heat generation and the current is cut off. It also has a function to

  The separator 102 of the present invention is not limited to a single-layer film such as polyolefin, but a three-layer structure in which a polypropylene film is sandwiched with a polyethylene film, or a laminate of a polyolefin microporous film and an organic nonwoven fabric may be used. I can do it. Thus, by making the separator 102 into multiple layers, various functions such as an overcurrent prevention function, an electrolyte holding function, and a separator shape maintenance (rigidity improvement) function can be provided.

  In the power generation element 108 described above, the positive electrode plates 101 and the negative electrode plates 103 are alternately stacked via the separators 102. The three positive plates 101 are respectively connected to the positive terminal 104 made of metal foil via the positive current collector 101a, while the three negative plates 103 are connected to the negative current collector 103a. In the same manner, each is connected to a negative electrode terminal 105 made of metal foil.

  In addition, the positive electrode plate 101, the separator 102, and the negative electrode plate 103 of the power generation element 108 are not limited to the above number in the present invention. For example, one positive electrode plate 101, three separators 102, and 1 The power generation element 108 can also be configured with a single negative plate 103, and can be configured by selecting the number of positive plates, separators, and negative plates as required.

  The positive electrode terminal 104 and the negative electrode terminal 105 are not particularly limited as long as they are electrochemically stable metal materials. Examples of the positive electrode terminal 104 include, for example, an aluminum foil and an aluminum alloy foil, similar to the positive electrode current collector 101a described above. , Copper foil, or nickel foil. Moreover, as the negative electrode terminal 105, nickel foil, copper foil, stainless steel foil, iron foil, etc. can be mentioned similarly to the above-mentioned negative electrode side collector 103a, for example. In the present embodiment, the metal foils constituting the current collectors 101 a and 103 a of the electrode plates 101 and 103 are extended to the electrode terminals 104 and 105, so that the electrode plates 101 and 103 are directly connected to the electrode terminals 104 and 105. Although connected, the current collectors 101a and 103a of the electrode plates 101 and 103 and the electrode terminals 104 and 105 are connected by a material or component different from the metal foil constituting the current collectors 101a and 103a. Also good.

  The power generation element 108 is accommodated and sealed between an upper exterior member 106 formed in a cup shape as shown in FIG. 2 and a flat lower exterior member 107. Both the upper exterior member 106 and the lower exterior member 107 (exterior member) in the present embodiment are not particularly illustrated, but, for example, polyethylene, modified polyethylene, polypropylene, modified polypropylene, or the like from the inside to the outside of the thin battery 10 , An inner layer (synthetic resin layer) composed of a resin film excellent in resistance to electrolytic solution and heat fusion such as ionomer, and an intermediate layer (metal layer) composed of a metal foil such as aluminum, for example And, for example, it has a three-layer structure including an outer layer (synthetic resin layer) made of a resin film excellent in electrical insulation such as a polyamide resin or a polyester resin. Therefore, both of the upper exterior member 106 and the lower exterior member 107 have, for example, one surface of a metal foil such as an aluminum foil (the inner surface of the secondary battery 10) resistant to an electrolytic solution such as polyethylene and heat fusion. A flexible material such as a resin-metal thin film laminate film in which the other surface (the outer surface of the secondary battery 10) is laminated with a resin having an excellent electrical insulation property such as a polyamide-based resin. It is formed with.

  As described above, when the exterior member includes the metal layer in addition to the resin layer, it is possible to improve the strength of the exterior member itself. Further, by forming the inner layer of the exterior member with a resin having excellent heat-fusibility, such as polyethylene, it is possible to ensure good fusing property with the metal electrode terminal.

  As shown in FIGS. 1 and 2, the positive terminal 104 is led out from one end of the sealed exterior members 106 and 107, and the negative terminal 105 is led out from the other end. Since a gap is formed in the fusion part between the upper exterior member 106 and the lower exterior member 107 by the thickness of 104, 105, the electrode terminals 104, 105 and the exterior are maintained in order to maintain the sealing performance inside the secondary battery 10. For example, a seal film made of polyethylene, polypropylene, or the like may be interposed in a portion where the members 106 and 107 come into contact. It is preferable from the viewpoint of heat-fusibility that this seal film is made of the same type of resin as the resin constituting the exterior members 106 and 107 in both the positive electrode terminal 104 and the negative electrode terminal 105.

  These exterior members 106 and 107 enclose the power generation element 108, part of the positive electrode terminal 104 and part of the negative electrode terminal 105 described above, and in the space formed by the exterior members 106 and 107, perchloric acid is added to the organic liquid solvent. While injecting a liquid electrolyte having a lithium salt such as lithium oxide, lithium borofluoride or lithium hexafluorophosphate as a solute, the space formed by the exterior members 106 and 107 is sucked into a vacuum state, and then the exterior member The outer peripheral edges of 106 and 107 are heat-sealed by hot press to form a heat-sealed portion 109 and sealed.

  Examples of the organic liquid solvent include ester solvents such as propylene carbonate (PC), ethylene carbonate (EC), dimethyl carbonate (DMC), and methyl ethyl carbonate, but the organic liquid solvent of the present invention is limited to this. Without limitation, an organic liquid solvent prepared by mixing and preparing an ether solvent such as γ-butylactone (γ-BL) or dietoshietane (DEE) in the ester solvent can be used.

  Below, the assembled battery 100a comprised by connecting two or more above-mentioned secondary batteries 10 is demonstrated.

  3 is an overall perspective view of the assembled battery according to the first embodiment of the present invention, FIG. 4 is a plan view showing the arrangement of battery stacks constituting the assembled battery shown in FIG. 3, and FIG. 5 is taken along the line VV in FIG. 6A to 6C are views showing a heat sink used in the assembled battery shown in FIG. 3, FIG. 6A is a plan view thereof, and FIG. 6B is a side view thereof. FIG. 6C is a front view thereof, and FIG. 7 is a graph showing temperature distribution in the plurality of battery stacks shown in FIGS.

  As shown in FIGS. 3 to 5, an assembled battery 100 a according to the first embodiment of the present invention includes eight battery stacks 30 a to 30 h each configured by stacking ten of the above-described secondary batteries 10. And the heat sink 20 in which the secondary batteries 10a to 10j included in the battery stacks 30a to 30h are interposed, and the housing 40 that houses the battery stacks 30a to 30h on the same plane and accommodates them in the internal space 41. An inlet duct 50 that communicates the outside of the assembled battery 100a and the internal space 41 of the housing 40 via the inlet-side opening 42 of the housing 40, and the internal space 41 of the housing 40 and the outside of the assembled battery 100a. Are provided through an outlet side opening 43 of the housing 40 and a fan 70 disposed in the outlet duct 60.

  First, the battery stacks 30a to 30h housed in the internal space 41 of the casing 40 of the assembled battery 100a will be described in detail. As shown in FIG. The secondary batteries 10a to 10j are stacked in 10 stages.

  Specifically, as shown in the figure, the first secondary battery 10a and the second secondary battery are arranged so that the lower exterior members 107 are in close contact with each other, that is, one secondary battery is in the other. In the same manner, the third secondary battery 10c and the fourth secondary battery 10d, the fifth secondary battery 10e and the sixth secondary battery are stacked in an inverted manner. The battery 10f, the seventh secondary battery 10g and the eighth secondary battery 10h, and the ninth secondary battery 10i and the tenth secondary battery 10j are stacked with the lower exterior member 107 in close contact with each other. Yes. In addition, in the secondary batteries in which the lower exterior members 107 are in close contact with each other, the same polarity terminals are directly joined by, for example, ultrasonic welding.

  Further, in each of the battery stacks 30a to 30h, the second secondary battery 10b and the third secondary battery 10c are arranged such that the upper exterior member 106 faces each other, that is, the other secondary battery is In a state of being turned upside down with respect to one of the secondary batteries, it is laminated via the heat sink 20, and in the same manner, the fourth secondary battery 10d, the fifth secondary battery 10e, and the sixth secondary battery. 10f and the seventh secondary battery 10g, and the eighth secondary battery 10h and the ninth secondary battery 10i are stacked via the heat sink 20 so that the upper exterior member 106 faces each other. Further, the uppermost layer and the lowermost layer heat sink 20 are laminated on the upper exterior member 106 of the first secondary battery 10a and the tenth secondary battery 10j, respectively. As shown in FIGS. 4 and 5, even in different battery stacks 30 a to 30 h, the same heat sink 20 is interposed in the same stage. Therefore, as shown in FIG. 5, a total of six heat sinks 20 are interposed in the assembled battery 100a.

  As shown in FIGS. 6A to 6C, each heat sink 20 in which each of the secondary batteries 10a to 10j is interposed is large enough to include the projected areas of the eight battery stacks 30a to 30h. For example, it is made of a metal material excellent in thermal conductivity and machinability such as an Al—Mg—Si based alloy represented by A6063, and has eight passages 21 in the longitudinal direction. It is comprised with the hollow extrusion molding material formed along the direction. The heat sink 20 is stacked on each of the battery stacks 30a to 30h so that the direction in which the passage 21 extends is substantially orthogonal to the direction in which the electrode terminals 104 and 105 of the secondary batteries 10a to 10i are led out. .

  As shown in FIG. 4, the eight battery stacks 30 a to 30 h configured as described above are arranged such that the lead-out directions of the electrode terminals 104 and 105 of the secondary batteries 10 a to 10 j are the entrance side openings 42 of the housing 40. Are arranged in two rows and four columns in the internal space 41 of the housing 40 so as to be substantially orthogonal to the direction from the first to the outlet side opening 43.

As shown in FIGS. 4 and 5, the eight battery stacks 30a to 30h arranged in this way are connected to the negative terminal 105 of each of the secondary batteries 10a to 10j of the first battery stack 30a and the fifth battery stack 30a to 30h. Are connected directly to the positive terminals 104 of the secondary batteries 10a to 10j in the same stage, and in the same manner, the negative terminals of the secondary batteries 10a to 10j of the second battery stack 30b. 105 and the positive terminal 104 of the secondary battery 10a to 10j in the same stage of the sixth battery stack 30f are directly joined, and the negative terminal 105 of each secondary battery 10a to 10j of the third battery stack 30c The positive terminals 104 of the secondary batteries 10a to 10j in the same stage of the seventh battery stack 30g are directly joined, and further, the negative terminals 105 of the secondary batteries 10a to 10j of the fourth battery stack 30d , Eighth battery stack 30h A positive terminal 104 of the same stage of the secondary battery 10a~10j is directly joined. The positive terminals 104 of the secondary batteries 10a to 10j of the first to fourth battery stacks 30a to 30d are electrically connected to each other through, for example, a bus bar (not shown). The negative terminals 105 of the secondary batteries 10a to 10j of the fifth to eighth battery stacks 30e to 30h are also electrically connected via, for example, a bus bar (not shown). As a method for joining the electrode terminals 104 and 105 or between the electrode terminals 104 and 105 and the bus bar, for example, ultrasonic welding, cold pressure welding or the like can be exemplified, and heat generation during energization due to a large current is considered. The electrode terminals 104 and 105 need to have an overlap margin of 10 to 15 mm ² or more, and the greater the overlap margin, the better the cooling efficiency by the cooling air.

  Between the battery stacks 30a to 30h arranged in this way, as shown in FIG. 5, a flow path is formed by the heat fusion part 109 of the exterior members 106 and 107 from which the electrode terminals 104 and 105 are led out. 31 is formed. As shown in the figure, each flow path 31 has a plurality of battery stacks 30a to 30h in which a plurality of thin secondary batteries 10a to 10j using a resin-metal thin film laminate film as exterior members 106 and 107 are stacked. In this case, since the heat fusion part 109 and the electrode terminals 104 and 105 of the exterior members 106 and 107 exist, a gap that is inevitably formed between the battery stacks 30a to 30h and the heat sink 20 is used. Thus, the secondary batteries 10a to 10j are formed so as to be substantially orthogonal to the lead-out direction of the electrode terminals 104 and 105, respectively.

  Next, the operation will be described.

  First, when the fan 70 of the assembled battery 100a is rotationally driven, negative pressure is generated in the inlet duct 50 and the inner space 41 of the casing 40, and the inner space 41 of the casing 40 is passed from the outside of the assembled battery 100a via the inlet duct 50. Cooling air is taken in.

  The cooling air taken into the internal space 41 from the inlet duct 50 through the inlet-side opening 42 of the housing 40 enters each passage 21 formed in the heat sink 20 and at the same time, between each battery stack 30a-30h. It enters into each flow path 31 formed in this.

  The cooling air that has entered the passages 21 passes through the passages 21 toward the outlet opening 43 of the housing 40 due to the negative pressure generated by the rotational drive of the fan 70. During this passage, the cooling air passing through each passage 21 cools the cup portion of the upper exterior member 106 via the heat sink 20, and the secondary batteries 10a to 10j are indirectly cooled by the cooling air. .

  In addition, the cooling air that has entered each flow path 31 is along a direction substantially orthogonal to the lead-out direction of the electrode terminals 104 and 105 of the secondary batteries 10a to 10j due to the negative pressure generated by the rotational drive of the fan 70. And pass through each flow path 31 toward the outlet opening 43 of the housing 40. During this passage, the cooling air passing through each flow path 31 cools each electrode terminal 104, 105, the inclined surface portion on the short side of the exterior member 106 and the heat fusion part 109, and each secondary battery 10 a to 10 j. Is directly cooled by the cooling air.

  The cooling air that has passed through each passage 21 and each flow path 31 and reached the outlet-side opening 43 of the housing 40 is discharged to the outside of the assembled battery 100 a through the outlet duct 60 by driving the fan 70. In the present invention, the refrigerant supplied by the refrigerant supply means is not limited to the cooling air taken from the outside of the assembled battery, and may be gas or liquid.

  In this way, in addition to indirect cooling by the heat sink 20, by directly applying cooling air to the secondary batteries 10 a to 10 j and directly cooling them, as shown in FIG. 7, only indirect cooling is adopted. Compared to the structure, the temperature distribution of the battery stacks 30a to 30h can be slid to the low temperature side as a whole. In addition, the position level of the vertical axis | shaft in the same figure shows the lamination | stacking position of the secondary batteries 10a-10j in each battery laminated body 30a-30h. Specifically, when the position level is zero, the innermost stage of the battery stack (the stages of the fifth and sixth secondary batteries 10e and 10f in FIG. 5) is shown, and the position level is in the positive direction. While going up to the upper side of the battery stack (the side of the ninth and tenth secondary batteries 10i, 10j in FIG. 5), the lower side of the battery stack (FIG. 5) as it goes down in the minus direction. 1 shows that the first and second secondary batteries 10a and 10b are stepped down). Therefore, from the same figure, in each of the battery stacks 30a to 30h, the convergence temperature of the fifth and sixth secondary batteries 10e and 10f located at the innermost stage where the position level is zero is the highest, and the position level is the highest. It can be seen that the first, second, ninth, and tenth secondary batteries 10a, 10b, 10i, and 10j located at the highest or lowest outermost stage have the lowest convergence temperature.

  FIG. 8 is a schematic diagram illustrating an example in which the assembled battery 100a according to the first embodiment is mounted below the floor of the vehicle 1 such as an electric vehicle. It is particularly effective to use an assembled battery composed of a secondary battery with improved cooling efficiency as described above for a vehicle such as an electric vehicle.

  As described above, in the assembled battery according to the first embodiment of the present invention, when a plurality of battery stacks in which a plurality of secondary batteries are stacked are arranged side by side, the heat fusion part of each secondary battery included in the battery stack is provided. And cooling the secondary battery directly by passing cooling air through the flow path formed between the battery stacks by the electrode terminals, compared with the indirect cooling only by the conventional heat sink. It becomes possible to cool the secondary battery which comprises a battery efficiently.

  In the assembled battery according to the first embodiment of the present invention, the secondary battery constituting the battery stack is directly cooled by cooling air, thereby complicating the shape of the heat sink or increasing the number of the heat sinks. The cooling efficiency of the secondary battery constituting the assembled battery can be improved without increasing the cost of the assembled battery.

  Furthermore, in the first embodiment of the present invention, when the battery stacks are arranged in an assembled battery in which a plurality of battery stacks in which a plurality of thin secondary batteries using a resin-metal thin film laminate film as an exterior member are stacked are arranged. In addition, since the gap inevitably formed by the heat-sealed portion of the exterior member and the electrode terminal is used as a flow path through which the cooling air passes, it is not necessary to bother to form a dedicated flow path for direct cooling.

  Further, when the flow path is formed exclusively for direct cooling, there is a risk that the formation of the flow path may increase the volume of the assembled battery. However, in the assembled battery according to the first embodiment of the present invention, the battery When a plurality of laminated bodies are arranged side by side, the gap inevitably formed by the heat-sealed portion and the electrode terminal of the exterior member of each secondary battery included in the battery laminated body is used as a flow path through which cooling air passes. Therefore, the cooling efficiency can be increased without increasing the volume of the assembled battery.

  Furthermore, in the assembled battery according to the first embodiment of the present invention, each secondary battery constituting the assembled battery is further efficiently cooled by directly cooling the metal electrode terminals having high thermal conductivity with cooling air. It becomes possible to do.

[Second Embodiment]
9 is a plan view showing the arrangement of the battery stack constituting the assembled battery according to the second embodiment of the present invention, FIG. 10 is a cross-sectional view taken along line XX of FIG. 9, and FIG. 11 is shown in FIGS. It is a graph which shows the temperature distribution in the some battery laminated body shown.

  In the assembled battery 100b according to the second embodiment of the present invention, the number and orientation of the battery stacks 30a to 30d in the internal space 41 of the housing 40 and the secondary batteries 10a to 10j of the battery stacks 30a to 30d are Although it is different from the assembled battery 100a according to the first embodiment described above in that it is stacked so as to deviate, other configurations are the same as the configuration of the assembled battery 100a according to the first embodiment. Only the difference between the assembled battery 100b according to the second embodiment and the assembled battery 100a according to the first embodiment will be described below.

  As shown in FIG. 9, the assembled battery 100 b according to the second embodiment of the present invention includes four battery stacks 30 a to 30 that are configured by stacking 10 secondary batteries 10 similar to those in the first embodiment. 30d. And these four battery laminated bodies 30a-30d, as shown in the figure, the lead-out direction of the electrode terminals 104 and 105 of each secondary battery 10a-10j is the outlet side opening from the inlet side opening 42 of the housing | casing 40. 43 is different from the assembled battery 100a according to the first embodiment in that it is arranged in two rows and two columns in the internal space 41 of the housing 40 so as to be substantially parallel to the direction toward 43.

  Incidentally, when the battery stack is arranged so that the lead-out direction of the electrode terminals is substantially perpendicular to the traveling direction of the cooling air as in the first embodiment, the lead-out direction of the electrode terminals as in this embodiment. When the battery stack is arranged so as to be substantially parallel to the traveling direction of the cooling air, the former temperature distribution width is τ1, and the latter temperature distribution width is τ2. Τ1 = ρ × τ2, where 0.5 ≦ ρ ≦ 0.9 (ρ value depends on the overlap between the electrode terminals in the first embodiment), and the electrode terminal is determined only by the exterior member. Although the cooling efficiency is better by about 10 to 50% when directly cooling, the arrangement of the battery stack inside the assembled battery case is the number and size of the battery stack, the connection method of the secondary battery, and It is set based on the size of the housing.

  Furthermore, each battery laminated body 30a-30d of the assembled battery 100b which concerns on this embodiment is 1st implementation by the point by which the some secondary battery 10a-10j which comprises the said battery laminated body 30a-30d is shifted and laminated | stacked. It differs from the assembled battery 100a which concerns on a form.

  Specifically, as shown in FIG. 10, the first battery stack 30a is directed toward the innermost secondary batteries 10e and 10f of the first battery stack 30a along the battery stacking direction. The secondary batteries 10a to 10j are stacked so as to approach the third battery stacked body 30c disposed on the side of the first battery stacked body 30a. Similarly, although not particularly illustrated, the second battery stack 30b is moved along the battery stacking direction toward the secondary batteries 10e and 10f arranged at the innermost stage of the second battery stack 30b. The secondary batteries 10a to 10j are stacked so as to approach the fourth battery stack 30d disposed on the side of the second battery stack 30b.

  In addition, as shown in FIG. 10, the third battery stack 30c moves along the battery stacking direction toward the innermost secondary batteries 10e, 10f of the third battery stack 30c. Each of the secondary batteries 10a to 10j is stacked so as to approach the first battery stack 30a disposed on the side of the third battery stack 30c. Similarly, although not specifically illustrated, the fourth battery stack 30d is directed toward the secondary batteries 10e and 10f arranged in the innermost stage of the fourth battery stack 30d along the battery stacking direction. The secondary batteries 10a to 10j are stacked so as to approach the second battery stacked body 30b disposed on the side of the fourth battery stacked body 30d.

  More specifically, as shown in FIG. 10, in the first battery stack 30a, the fifth and sixth secondary batteries 10e and 10f stacked in the innermost stage are next in the outer stage. The stacked third and fourth secondary batteries 10c and 10d and the seventh and eighth secondary batteries 10g and 10h are stacked so as to be separated from the third battery stack 30c by an offset amount α. . Further, in the first battery stack 30a, the first and second secondary batteries 10a and 10b stacked in the outermost stage and the ninth and tenth secondary batteries 10i and 10j are the innermost. The secondary batteries 10e and 10f are stacked so as to be separated from the third battery stack 30c by an offset amount β (where α <β).

  Also in the third battery stack 30c, as shown in the figure, the fifth and sixth secondary batteries 10e and 10f stacked in the innermost stage are then stacked in the outer stage. The third, fourth, seventh, and eighth secondary batteries 10c, 10d, 10g, and 10h are stacked so as to be separated from the first battery stack 30a by an offset amount α, and further stacked on the outermost stage. The first, second, ninth and tenth secondary batteries 10a, 10b, 10i and 10j are stacked so as to be separated from the first battery stack 30a by an offset amount β. In this embodiment, one battery stack is shifted and stacked, and other battery stacks adjacent thereto are also shifted and stacked. However, in the present invention, only one battery stack is shifted and stacked. You may do it.

  Therefore, as shown in FIG. 10, the first battery stack 30a and the third battery stack 30c are arranged such that the innermost secondary batteries 10e and 10f of the stacks 30a and 30c are closest to each other. On the other hand, the secondary batteries 10c, 10d, 10g, and 10h stacked next in the outer stage are stacked with an offset amount of 2 × α separated, and further, the secondary batteries stacked in the outermost stage Secondary batteries 10a, 10b, 10i and 10j are stacked apart from each other by an offset amount of 2 × β.

  Although not shown in particular, the second battery stack 30b and the fourth battery stack 30d are also closest to the innermost secondary batteries 10e and 10f, whereas the second The secondary batteries 10c, 10d, 10h, and 10g are stacked apart from each other by an offset amount 2 × α, and the outermost secondary batteries 10a, 10b, 10i, and 10j are separated from each other by an offset amount 2 × β. Are stacked.

  In each of the battery stacks 30a to 30d arranged in this way, as shown in FIG. 10, flow paths 32a to 32c are formed by the heat-sealing portions 109 of the exterior members 106 and 107 of the secondary batteries 10a to 10j. Has been.

  As shown in the figure, each of the flow paths 32a to 32c includes a plurality of battery stacks 30a to 30d each including a plurality of thin secondary batteries 10a to 10j each using a resin-metal thin film laminate film as the exterior members 106 and 107. Since the heat fusion part 109 of the exterior members 106 and 107 exists when arranged side by side, two gaps inevitably formed between the battery stacks 30a to 30d and the heat sink 20 are used. Each of the secondary batteries 10a to 10j is formed along the longitudinal direction.

  As shown in FIG. 10, these flow paths 32 a to 32 c are formed as the battery stacks 30 a to 30 d are configured by offsetting and stacking the secondary batteries as described above, as shown in FIG. 10. The cross-sectional area is large.

  Specifically, the flow path 32a (the flow path formed between the fifth and sixth secondary batteries 10e and 10f in FIG. 10) located at the innermost stage of each battery stack 30a to 30d is interrupted. The flow path 32b that has the smallest area Sa and is positioned next to the outer stage (the flow formed between the third, fourth, seventh, and eighth secondary batteries 10c, 10d, 10g, and 10h in FIG. 10). The cross-sectional area Sb of the second channel is the next largest, and the flow path 32c (in FIG. 10, the first, second, ninth and tenth secondary batteries 10a, 10b, 10i and 10j) The cross-sectional area Sc of the channel formed between them is the largest (Sa <Sb <Sc).

  The operation of the assembled battery according to the present embodiment will be described. Similarly to the first embodiment, a negative pressure is generated in the assembled battery as the fan 70 is driven to rotate, and accordingly, the inlet duct from the outside of the assembled battery. The cooling air is taken into the internal space 41 of the housing 40 through 50 and enters the passages 21 formed in the heat sink 20, and at the same time, the flow paths 32 a to 32 a formed between the battery stacks 30 a to 30 d. Enter 32c. As in the first embodiment, the heat sink 20 is such that the direction in which the passage 21 extends is substantially parallel to the direction from the inlet side opening 42 to the outlet side opening 43 of the housing 40. Has been placed.

  The cooling air that has entered each passage 21 passes through each passage 21 due to negative pressure toward the outlet-side opening 43 of the housing 40, as in the first embodiment. The cooling air passing through the passages 21 indirectly cools the secondary batteries 10 a to 10 j via the heat sink 20.

  Further, the cooling air that has entered each flow path 32 passes through each flow path 32 along the longitudinal direction of each of the secondary batteries 10 a to 10 j toward the outlet side opening 43 of the housing 40 due to negative pressure. The cooling air passing through each flow path 32 cools the inclined surface portion and the thermal fusion bonding portion 109 on the long side of the exterior member 106, and the secondary batteries 10a to 10j are directly cooled by the cooling air.

At this time, as described above, each of the flow paths 32a to 32c is formed so that the cross-sectional area increases from the center of the battery stacks 30a to 30d to the outside (Sa <Sb <Sc). When the cooling air having a predetermined air volume V [m ³ / min] generated by the rotational driving of 70 enters the respective flow paths 32a to 32c, the wind speed Va in the innermost flow path 32a of the battery stacks 30a to 30d. V / Sa, the wind speed Vb in the outer-stage flow path 32b is V / Sb, the wind speed Vc in the outermost-stage flow path 32c is V / Sc, and the wind speed Va in the innermost-stage flow path 32a. The wind speed becomes slower as going to the outer stage (Va>Vb> Vc), and the wind speed of the cooling wind becomes faster toward the center of the battery stacks 30a to 30d.

  The cooling air that has passed through the passages 21 and the flow paths 32 a to 32 c and reached the outlet opening 43 of the housing 40 is discharged to the outside of the assembled battery 100 b through the outlet duct 60 by driving the fan 70. .

  In this way, the cooling air is passed through the flow path 32a formed between the innermost secondary batteries 10e and 10f where the convergence temperature of the secondary battery is high, while the convergence temperature is compared. When the secondary battery is not displaced by passing cooling air at a low wind speed through the flow path 32c formed between the secondary batteries 10a, 10b, 10i, and 10j at the lowest outermost level (the one-dot chain line in FIG. 7). 11), the convergence temperature Ta ′ of the innermost secondary batteries 10e and 10f in the battery stacks 10a to 10d and the outermost secondary batteries 10a, 10b, and 10i as shown in FIG. And the temperature variation | Tc′−Ta ′ | which is a difference from the convergence temperature Tc ′ of 10j can be suppressed.

  Note that the offset amounts α and β shown in FIG. 10 can be arbitrarily set by adjusting the overlap allowance in the battery stacks 30a to 30d without the exterior members 106 and 107 of the adjacent secondary batteries 10a to 10j coming into contact with each other. The temperature variation is set as close to zero as possible.

  In addition, as shown in FIG. 10, the assembled battery 100b according to the present embodiment includes the battery stacks 30a to 30d because the secondary batteries 10a to 10j are shifted and stacked to form the battery stacks 30a to 30d. A gap having a substantially cross-sectional triangle shape is formed between the battery 40 and the housing 40, and the detection line, thermistor, and thermocouple for detecting the voltage and temperature of each of the secondary batteries 10a to 10j are arranged in the gap. By using it as the wiring space 33, it is possible to configure the assembled battery without increasing the volume of the entire assembled battery. Specifically, the cross-sectional area γ of the wiring space 33 in the assembled battery according to the present embodiment has the above-described offset amount β when the width of the secondary battery 10 is W and the height of the battery stack 30 is H. Therefore, γ = (H × β) / 2 × 2 = H × β can be expressed. However, H ≦ 100 mm, and β is limited by the control amount of the wind speed, the width of the heat sink, and the like.

  As described above, the cooling air is passed through the gap formed between the battery stacks 30a to 30d, and the wirings are concentrated in the gap formed between the battery stacks 30a to 30d and the housing 40. By arranging the batteries, the secondary battery can be shifted and stacked to form a battery stack without increasing the overall volume of the assembled battery. The wiring space 33 is configured such that cooling air cannot enter, and a reduction in cooling efficiency is prevented.

  As described above, in the assembled battery according to the second embodiment of the present invention, when a plurality of battery stacks in which a plurality of secondary batteries are stacked are arranged side by side, the heat fusion part of each secondary battery included in the battery stack is provided. As a result, the secondary battery is directly cooled by passing cooling air through the flow path formed between the battery stacks, thereby forming an assembled battery as compared with indirect cooling using only a conventional heat sink. The secondary battery can be efficiently cooled.

  Further, in the assembled battery according to the second embodiment of the present invention, the secondary battery constituting the battery stack is directly cooled by cooling air so that the heat sink is complicated or the number of the batteries is increased. Thus, the cooling efficiency of the secondary battery constituting the assembled battery can be improved without incurring an increase in cost.

  Furthermore, in the second embodiment of the present invention, when the battery stacks are arranged in an assembled battery in which a plurality of battery stacks in which a plurality of thin secondary batteries using a resin-metal thin film laminate film as an exterior member are stacked are arranged. In addition, since the gap inevitably formed by the heat-sealed portion of the exterior member is used as a flow path through which the cooling air passes, it is not necessary to bother to form a dedicated flow path for direct cooling.

  In addition, when the flow path is formed exclusively for direct cooling, there is a risk that the formation of the flow path may increase the volume of the assembled battery. However, in the assembled battery according to the second embodiment of the present invention, the battery When a plurality of stacked bodies are arranged side by side, the gap inevitably formed by the heat-sealed portion of the exterior member of each secondary battery included in the battery stacked body is used as a flow path through which the cooling air passes. Cooling efficiency can be increased without increasing the volume of the battery.

  Furthermore, in the assembled battery according to the second embodiment of the present invention, a plurality of secondary batteries are stacked in a shifted manner so that the cross-sectional area of the flow path at the center of the battery stack is minimized. Therefore, the temperature variation in the battery stack is increased by increasing the cooling air velocity at the center where the convergence temperature is high and decreasing the cooling air velocity at the outer periphery where the convergence temperature is low. Can be suppressed.

  In the assembled battery according to the second embodiment of the present invention, a wide contact area between the cooling air and the secondary battery can be secured by directly blowing the cooling air along the longitudinal direction of the secondary battery. Therefore, it becomes possible to cool each secondary battery which comprises an assembled battery more efficiently.

[Third Embodiment]
12 is a perspective view showing a case in which a battery stack is accommodated in the third embodiment of the present invention. FIG. 13 is an exploded perspective view showing the case and the battery stack shown in FIG. FIG. 14 is a cross-sectional view showing in detail a case opening and an air scoop in the third embodiment of the present invention, and FIG. 15 shows an array of battery stacks constituting the assembled battery according to the third embodiment of the present invention. FIG. 16 is a cross-sectional view taken along the line XVI-XVI of FIG. 15, FIG. 17 is a graph showing the relationship between the area of the opening and the maximum battery temperature in the third embodiment of the present invention, and FIG. It is a graph which shows the relationship between the length of the opening part in 3rd Embodiment of this invention, and the largest stress and displacement which arises around the said opening part.

  The configurations of the secondary battery 10, the casing 40, the inlet duct 50, the outlet duct 60, and the fan 70 used in the assembled battery 100c according to the third embodiment of the present invention are the same as those described in the first embodiment. It is. Only the difference between the assembled battery 100c according to the third embodiment and the assembled battery 100a according to the first embodiment will be described below.

  In the assembled battery 100c according to the present embodiment, as shown in FIGS. 12 and 13, eight secondary batteries 10a to 10h are stacked in such a posture that the electrode terminals 104 and 105 are led out in substantially the same direction. By doing so, the battery stack 30 is configured. In this embodiment, the battery stack 30 is accommodated in a hollow case 35.

  The case 35 includes a lower case 36 having a box shape with one surface open, and an upper case 37 forming a lid for closing the opening. The edge 37a of the upper case 37 is wound around the edge 36d of the peripheral wall 36c of the lower case 36 by caulking (see a partially enlarged cross-sectional view in FIG. 12). The lower case 36 and the upper case 37 are made of a plate material made of a material having excellent heat transfer properties such as a relatively thin aluminum plate or steel plate, and are given a predetermined shape by press working.

  The secondary batteries 10a to 10h constituting the battery stack 30 are connected in series in the spacer portion 35a such that the electrode terminals 104 and 105 are directly connected or connected via a bus bar (not shown). The secondary batteries 10 a to 10 k are electrically connected to the positive electrode output terminal 38 and the negative electrode output terminal 39 as a result.

  The positive electrode output terminal 38 is led out from the case 35 through a first notch 36e formed in a part of the peripheral wall 36c of the lower case 36. Similarly, the negative output terminal 39 is also led out from the case 35 via a second notch 36f formed in a part of the peripheral wall 36c of the lower case 36. A third cutout 36g is formed in a part of the peripheral wall 36c of the lower case 36, and the female connector 35c is led out from the case 35 through the third cutout 36g. Although not particularly shown, the female connector 35c is connected to the electrode terminals 104 and 105 of the secondary batteries 10a to 10h in the spacer portion 35a, and a male connector (not shown) is inserted. By detecting the voltage of each of the secondary batteries 10a to 10h by a voltage detector (not shown) connected to the battery pack 100, it is possible to perform charge / discharge management of the assembled battery 100c. Insulating covers 35b for maintaining insulation are interposed between the positive electrode output terminal 38, the female connector 35c, and the negative electrode output terminal 39, respectively.

  In order to insert bolts (not shown) at four corners of the case 35, through holes 36h are formed at the four corners of the lower case 36, and through the four corners of the upper case 37. A hole 37b is formed. In addition, through holes 35a1 through which the sleeves 35d are inserted are also formed at two positions on both ends of each spacer portion 35a.

  The case 35 having the above configuration is assembled as follows. That is, after attaching the spacer part 35a to the bipolar terminals 104 and 105 of the eight stacked secondary batteries 10a to 10h and accommodating them in the lower case 36, the sleeves 35d are inserted into the respective through holes 35a1 of the spacer part 35a. After placing the cushioning material 35e on the upper surface of each spacer portion 35a and covering the lower case 36 with the upper case 37, the edge portion 37a of the upper case 37 is wound around the edge portion 36d of the peripheral wall 36c of the lower case 36. The upper case 37 is fixed.

  In the secondary batteries 10a to 10h in the present embodiment using a flexible resin-metal thin film laminate film as the exterior members 106 and 107, the distance between the electrode plates 101 and 103 is made uniform in order to maintain the battery performance. Need to keep. On the other hand, in the present embodiment, the uppermost and lowermost secondary batteries 10a and 10j are in close contact with the upper and lower inner wall surfaces of the case 35 and the secondary batteries 10a to 10h are in close contact with each other in the case 35. It is possible to apply pressure in the stacking direction of the electrode plates 101 and 103 by housing in the container. In addition to this, the secondary batteries 10a to 10h and the upper and lower surfaces of the case 35 are in close contact with each other, so that the secondary batteries 10a to 10h can be dissipated through the upper and lower surfaces of the case 35. It is possible.

  In addition to the above-described configuration, in this embodiment, as shown in FIGS. 12 to 14, the interior of the case 35 is communicated with the outside through a part of the peripheral wall 36 c of the lower case 36 constituting the case 35. Two openings 36 a are formed, and cooling air supplied by the fan 70 via the inlet duct 50 can be introduced into or discharged from the case 35. FIG. 14 is a view in which the opening 36a and the air scoop 36b are cut along a plane parallel to the lead-out direction of the electrode terminals 104 and 105 of the secondary batteries 10a to 10h housed in the case 35.

  Each opening 36a is formed at a total of four locations on both ends of the two peripheral walls 36c1 along the longitudinal direction of the secondary batteries 10a to 10h (the lead-out direction of the electrode terminals 104 and 105) in the peripheral wall 36c of the lower case 36. And located near the positive terminal 104 or the negative terminal 105 of each of the secondary batteries 10a to 10k. Incidentally, in FIG. 12, the heat fusion part 109 of each secondary battery 10a-10h accommodated in the case 35 can be seen through the opening part 36a.

  In the present embodiment, air scoops 36b for directing the cooling air supplied through the inlet duct 50 toward the openings 36a are provided around the openings 36a.

  The air scoop 36b provided around the opening 36a formed on the negative electrode terminal 105 side in the peripheral wall 36c1 of the lower case 36 is provided around the positive electrode terminal 104 side of the opening 36a as shown in FIG. In addition, the bulge to the outside of the case 35 gradually decreases from the negative electrode terminal 105 side toward the positive electrode terminal 104 side.

  On the other hand, the air scoop 36b provided around the opening 36a formed on the positive electrode terminal 104 side in the peripheral wall 36c1 of the lower case 36 is provided around the negative electrode terminal 105 side of the opening 36a. The shape is such that the rise to the outside of the case 35 gradually decreases from the terminal 104 side toward the negative electrode terminal 105 side.

  Each air scoop 36b is formed, for example, by performing a pressing process that raises the peripheral wall 36c1 itself of the lower case 36, but may rise from the tightening portion formed on the edge 36d of the lower case 36. It is formed so that there is no.

  As shown in FIGS. 15 and 16, the assembled battery 100 c according to the present embodiment is composed of twelve battery stacks 30 a to 30 l configured as described above, and each battery stack 30 a to 30 l. Are arranged in the internal space 41 of the housing 40 while being accommodated in the cases 35a to 35l, respectively. Cases 35a to 35l each housing battery stacks 30a to 30l are arranged such that the lead-out directions of electrode terminals 104 and 105 of secondary batteries 10a to 10h housed therein are from inlet side opening 42 to outlet side opening 43 of case 40, respectively. Are arranged in three rows and four rows in an internal space 41 of the housing 40 in a posture along the direction toward the head. The battery stacks 30a to 30l are respectively housed in cases 35a to 35l having the same alphabetical characters at the end of the reference characters 30a to 30l at the end of the reference characters.

  Collars (not shown) are interposed between the cases 35a to 35l stacked in three stages, and are stacked with a space therebetween. Further, the mutually adjacent cases 35a to 35l are arranged in parallel with a space therebetween so as to allow the winding portion of the lower case 36 to be allowed. The output terminals 38 and 39 of the cases 35a to 35l are electrically connected to terminals led out from the housing through cables or the like.

  Next, the operation will be described.

  First, when the fan 70 of the assembled battery 100c is rotationally driven, negative pressure is generated in the inlet duct 50 and the inner space 41 of the housing 40, and the inner space 41 of the housing 40 is passed from the outside of the assembled battery 100c via the inlet duct 50. Cooling air is taken in.

  The cooling air taken into the internal space 41 from the inlet duct 50 through the inlet-side opening 42 of the housing 40 enters a space formed between the cases 35a to 35l. The cases 35a to 35l themselves are cooled by the cooling air passing through the space, and the secondary batteries 10a to 10h accommodated in the cases 35a to 35l are indirectly cooled via the cases 35a to 35l. The

  Further, as shown in FIG. 15, a part of the cooling air that has entered the space passes through the opening 36 a formed on one end side of the peripheral wall 36 c 1 of the lower case 36 of each of the cases 35 a to 35 l from the case 40. The cooling air enters the internal space 41 and passes through the flow path 34 formed inside the case 35, and the cooling air cools the inclined surface portion and the heat-sealing portion 109 on the long side of the exterior member 106, and each secondary battery 10a. -10 h is directly cooled by the cooling air.

  As shown in the partially enlarged cross-sectional view of FIG. 16, the flow path 34 through which the cooling air passes is between the secondary batteries 10 a to 10 h housed in the case 35 and the inner wall surface 351 of the case 35 facing it. Is formed. When the battery stack 30 in which a plurality of thin secondary batteries 10 a to 10 h using a resin-metal thin film laminate film are stacked as the exterior members 106 and 107 is accommodated in the case 35, the flow path 34 is provided with the exterior member. Since the heat-sealed portions 109 of 106 and 107 exist, they are formed by utilizing a gap that is inevitably formed between the battery stack 30 and the inner wall surface 351 of the case 35. In the present embodiment, the flow path 34 is formed along the lead-out direction of the electrode terminals 104 and 105 of the secondary batteries 10a to 10h, as shown in FIG.

  Here, when comparing the cooling effect with the case where the conventional case in which the opening is not formed is adopted, as shown in FIG. 17, when the opening 36a is formed in the case 35 as in the present embodiment, The cooling efficiency is improved by direct cooling of the cooling air introduced from the opening 36a, and the maximum temperature reached of the secondary batteries 10a to 10h accommodated in the case 35 is remarkably lowered. However, if the length of the opening 36a along the lead-out direction of the electrode terminals 104 and 105 of the secondary batteries 10a to 10h is too long, the opening is obtained when a predetermined force is applied to the case 35 as shown in FIG. A change occurs in the maximum stress applied around the portion 36a. Therefore, although depending on the thickness of the case 35, the length of the opening 36a is about 30% or less of the length of the case 35 along the lead-out direction of the electrode terminals 104 and 105 of the secondary batteries 10a to 10h. It is preferable to do. Note that L20, L40, and L80 in FIG. 17 are 20 mm, 40 mm, and 80 mm in length of the opening 36a along the lead-out direction of the electrode terminals 104, 105 of the secondary batteries 10a-10h accommodated in the case 35. FIG. 17 is a graph in which the opening area of the opening 36a is changed by changing the length while keeping the width of the opening 36a constant.

  As shown in FIG. 15, the cooling air that has passed through the flow path 34 in the case 35 is discharged into the internal space 41 of the housing 40 from the opening 36a formed on the other end side of the peripheral wall 36c1. The cooling air discharged from the opening 36 a reaches the outlet side opening 43 of the housing 40 together with the cooling air that has passed between the cases 35 a to 35 l, and is further driven by the fan 70 through the outlet duct 60. It is discharged outside the assembled battery 100c.

  As described above, the assembled battery according to the third embodiment of the present invention includes a case in which a plurality of cases in which a plurality of battery stacks in which a plurality of secondary batteries are stacked are arranged side by side, and the inner wall surface of the case, the battery stack, The assembled battery can be efficiently cooled by allowing the cooling air to pass through the flow path formed between the two and directly cooling the secondary battery.

  Moreover, in 3rd Embodiment of this invention, when the battery laminated body which laminated | stacked the thin secondary battery using the resin-metal thin film laminate film as an exterior member was accommodated in the case, of the exterior member of a secondary battery. The gap that is inevitably formed between the battery stack and the inner wall surface of the case by the heat-sealing part is used as a flow path through which the cooling air passes, so a dedicated flow path is used for direct cooling. There is no need to form. Thereby, the cooling efficiency can be increased without increasing the volume of the assembled battery.

  Furthermore, in the third embodiment of the present invention, by stacking the cases with a predetermined interval, the cooling air passes through the interval and the case itself is cooled. In addition, the secondary battery accommodated in the case can be indirectly cooled.

  In the third embodiment of the present invention, since the cooling air is directly blown along the longitudinal direction of the secondary battery, a wide contact area between the cooling air and the secondary battery can be secured. Can be further efficiently cooled.

[Fourth Embodiment]
FIG. 19 is a plan view showing an array of battery stacks constituting the assembled battery according to the fourth embodiment of the present invention.

  The assembled battery 100d according to the fourth embodiment of the present invention is different from the assembled battery 100c according to the third embodiment described above in that the directions of the cases 35a to 35l arranged in the internal space 41 of the housing 40 are different. The configuration is the same as that of the assembled battery 100c according to the third embodiment. Hereinafter, only the difference between the assembled battery 100d according to the fourth embodiment and the assembled battery 100c according to the third embodiment will be described.

  The assembled battery 100d according to the fourth embodiment of the present invention includes 12 battery stacks 30a to 30l configured by stacking eight stages of secondary batteries 10 similar to those of the third embodiment. The stacked bodies 30a to 30l are arranged in the internal space 41 of the housing 40 in a state of being accommodated in the cases 35a to 35l. In the present embodiment, as shown in FIG. 19, the cases 35 a to 35 l are arranged so that the electrode terminals 104 and 105 of the secondary batteries 10 a to 10 h are led out from the inlet side opening 42 of the housing 40 to the outlet side opening. The battery pack 100 is different from the assembled battery 100 c according to the third embodiment in that it is arranged in 12 rows in the internal space 41 of the housing 40 so as to be substantially orthogonal to the direction toward 43. That is, in the above-described third embodiment, the cases 35a to 35l are arranged in a state of being laid in the internal space of the housing 40, whereas in the present embodiment, the cases 35a to 35l are erected. It differs in that it is arranged in the internal space 41 of the body 40.

  The operation of the assembled battery 100d according to the present embodiment will be described. Similarly to the third embodiment, a negative pressure is generated in the assembled battery when the fan 70 is driven to rotate. Cooling air is taken into the internal space 41 of the housing 40 through the duct 50 and enters the space formed between the cases 35a to 35l, and the cases 35a to 35l are passed through the cases 35a to 35l. The secondary batteries 10a to 10h housed in the are indirectly cooled.

  Further, a part of the cooling air entering the space enters the internal space 41 of the housing 40 from the opening 36a formed in one peripheral wall 36c1 of the lower case 36 of each of the cases 35a to 35l and enters the inside of the case 35. Passing through the formed flow path 34, the cooling air cools the electrode terminals 104 and 105 and the inclined surface portion and the thermal fusion bonding portion 109 on the short side of the exterior member 106, and each secondary battery 10a. -10 h is directly cooled by the cooling air.

  Although not particularly illustrated, the flow path 34 is formed between each of the secondary batteries 10a to 10h accommodated in the case 35 and the inner wall surface 351 of the case 35 facing the secondary battery 10a. It is formed using a gap that is inevitably formed by the presence of the thermal fusion part 109 and the electrode terminals 104 and 105 of 10 hours. In the present embodiment, as shown in FIG. 19, the flow path 34 is formed along a direction substantially orthogonal to the lead-out direction of the electrode terminals 104 and 105 of the secondary batteries 10a to 10h.

  The cooling air that has passed through the flow path 34 in the case 35 is discharged into the internal space 41 of the housing 40 from the opening 36a formed in the other peripheral wall 36c1. The cooling air discharged from the opening 36 a reaches the outlet side opening 43 of the housing 40 together with the cooling air that has passed between the cases 35 a to 35 l, and is further driven by the fan 70 through the outlet duct 60. It is discharged outside the assembled battery 100d.

  As described above, the assembled battery according to the fourth embodiment of the present invention includes an inner wall surface of the case, a battery stack, and a case in which a plurality of cases each containing a battery stack in which a plurality of secondary batteries are stacked are arranged side by side. The assembled battery can be efficiently cooled by allowing the cooling air to pass through the flow path formed between the two and directly cooling the secondary battery.

  Further, in the fourth embodiment of the present invention, when a battery in which a plurality of thin secondary batteries using a resin-metal thin film laminate film is used as an exterior member is accommodated in a case, the heat fusion of the exterior member of the secondary battery is performed. Since the gap that is inevitably formed between the battery stack and the inner wall surface of the case is used as a flow path through which the cooling air passes, a dedicated flow path for direct cooling is purposely formed. There is no need. Thereby, the cooling efficiency can be increased without increasing the volume of the assembled battery.

Furthermore, in the fourth embodiment of the present invention, by stacking the cases with a predetermined interval, the cooling air passes through the interval and the case itself is cooled. In addition, the secondary battery accommodated in the case can be indirectly cooled.

  Further, in the fourth embodiment of the present invention, each secondary battery constituting the assembled battery can be more efficiently cooled by directly cooling the metal electrode terminal having high thermal conductivity with the cooling air. It becomes.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  In the above-described first embodiment, eight sets of battery stacks in which 10 stages of secondary batteries are stacked are arranged to constitute an assembled battery, and in the second embodiment, four sets of similar battery stacks are arranged to form an assembled battery. However, the present invention is not particularly limited thereto, and one battery stack may be formed by stacking N secondary batteries, and M battery stacks are arranged in an arbitrary arrangement. (Where M and N are any natural numbers).

  Similarly, in the above-described third and fourth embodiments, the battery pack is configured by arranging 12 battery stacks in which 8 stages of secondary batteries are stacked. However, in the present invention, the present invention is not particularly limited to this. The battery stack may be formed by stacking N secondary batteries. M sets of battery stacks can be arranged.

  In the first, third, and fourth embodiments, the battery stack may be configured by shifting and stacking the secondary batteries as in the second embodiment. Furthermore, the assembled battery according to the second to fourth embodiments may be mounted under the vehicle floor described in the first embodiment.

FIG. 1 is a plan view of an entire secondary battery according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the secondary battery taken along line II-II in FIG. FIG. 3 is an overall perspective view of the assembled battery according to the first embodiment of the present invention. FIG. 4 is a plan view showing an arrangement of battery stacks constituting the assembled battery shown in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. 6A to 6C are views showing a heat sink used in the assembled battery shown in FIG. 3, wherein FIG. 6A is a plan view thereof, FIG. 6B is a side view thereof, and FIG. C) is a front view thereof. FIG. 7 is a graph showing the temperature distribution in the plurality of battery stacks shown in FIGS. 4 and 5. FIG. 8 is a schematic view of a vehicle equipped with the assembled battery according to the first embodiment of the present invention. FIG. 9 is a plan view showing the arrangement of the battery stack constituting the assembled battery according to the second embodiment of the present invention. FIG. 10 is a cross-sectional view taken along line XX in FIG. FIG. 11 is a graph showing temperature distribution in the plurality of battery stacks shown in FIGS. 9 and 10. FIG. 12 is a perspective view showing a case in which the battery stack is housed in the assembled battery according to the third embodiment of the present invention. FIG. 13 is an exploded perspective view showing the case and battery stack shown in FIG. FIG. 14 is a cross-sectional view showing in detail the opening and air scoop formed in the case. FIG. 15 is a plan view showing the arrangement of the battery stack constituting the assembled battery according to the third embodiment of the present invention. 16 is a cross-sectional view taken along line XVI-XVI in FIG. FIG. 17 is a graph showing the relationship between the area of the opening and the maximum temperature reached by the battery in the third embodiment of the present invention. FIG. 18 is a graph showing the relationship between the length of the opening and the maximum stress / displacement generated around the opening in the third embodiment of the present invention. FIG. 19 is a plan view showing the arrangement of the battery stack constituting the assembled battery according to the fourth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle 10, 10a-10j ... Secondary battery 20 ... Heat sink 21 ... Passage 30, 30a-30l ... Battery laminated body 31, 32a-32c, 34 ... Channel 33 ... Space 35 for wiring, 35a-35l ... Case 36 ... lower case 36a ... opening 36b ... air scoop 36c ... peripheral wall 36d ... edge parts 36e to 37g ... first to third notches 36h ... through hole 37 ... upper case 37a ... edge part 37b ... through hole 38 ... positive electrode output terminal 39 ... Negative electrode output terminal 40 ... Housing 41 ... Internal space 42 ... Inlet side opening 43 ... Outlet side opening 50 ... Inlet duct 60 ... Outlet duct 70 ... Fans 100a to 100d ... Assembly battery

Claims (12)

The electrode plates laminated via the separator are accommodated in an exterior member having a synthetic resin layer made of a synthetic resin material and a metal layer made of a metal material, and the outer peripheral edge of the exterior member is heat-sealed to form a heat-sealed portion. A battery assembly including a battery stack in which a plurality of secondary batteries in which electrode terminals connected to the electrode plate are led out from the outer peripheral edge of the exterior member are stacked are formed. ,
Refrigerant supply means for supplying a refrigerant for cooling the secondary battery;
A case capable of accommodating the battery stack therein;
A housing having an inlet-side opening and an outlet-side opening to which the refrigerant supply means is connected, and housing the case;
The case is formed with a plurality of openings for introducing or discharging the refrigerant supplied from the refrigerant supply means into the case,
The refrigerant supplied from the refrigerant supply means is introduced into the case through the one opening, and is formed between the inner wall surface of the case and the battery stack by the heat fusion part of the secondary battery. Passes through the formed flow path, is discharged from the case through the other opening,
An assembled battery in which an air scoop is provided around the opening of the case to direct the refrigerant supplied from the refrigerant supply means toward the opening.   The assembled battery according to claim 1, wherein the refrigerant supplied from the refrigerant supply means passes through the flow path while directly touching the secondary battery.   The assembled battery according to claim 1 or 2, wherein the plurality of secondary batteries are in close contact with each other, and the uppermost and lowermost secondary batteries of the battery stack are in close contact with the inner wall surface of the case. The assembled battery according to any one of claims 1 to 3, wherein another case is stacked on the case at a predetermined interval. The assembled battery according to any one of claims 1 to 4, wherein the flow path is formed along a longitudinal direction of the secondary battery. The assembled battery according to any one of claims 1 to 4, wherein the flow path is formed so as to be substantially orthogonal to a direction in which an electrode terminal of the secondary battery is led out. The battery stack is assembled battery according to any one of claims 1 to 6, wherein said plurality of secondary batteries are formed by laminating to be shifted. As the one battery stack moves toward the center of the one battery stack along the stacking direction of the secondary batteries of the one battery stack, each secondary battery approaches the other battery stack. The assembled battery according to claim 7, which is laminated as described above. Further, each of the secondary battery stacks moves toward the center of the other battery stack along the stacking direction of the secondary batteries of the other battery stack. The assembled battery according to claim 8 , wherein the battery pack is stacked so as to approach the battery. Electrode plate of the secondary battery, lithium - manganese composite oxide, lithium - nickel compound oxide or lithium - claim including a positive electrode plate having a positive electrode active material composed of cobalt-based composite oxide 1-9 The assembled battery according to any one of the above. The assembled battery according to any one of claims 1 to 10 , wherein the electrode plate of the secondary battery includes a negative electrode plate having a negative electrode active material made of a crystalline carbon material or an amorphous carbon material. A vehicle equipped with the assembled battery according to any one of claims 1 to 11 .

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