Description Title of Lnvention BATTERY UNIT, BATTERY MODULE, POWER STORAGE SYSTEM, 5 ELECTRONIC DEVICE, POWER SYSTEM, AND ELECTRIC VEHICLE Technical Field [OOOl] The present disclosure relates to a battery unit, a battery module, a power 10 storage system, an electronic device, a power system, and an electric vehicle. Background Art [OO02] Lithium ion seconda~yb atteries that use carbon for a negative electrode, a 15 lithium-transition metal composite oxide for a positive electrode, and a carbonate mixture for an electrolyte have been widely known for some time. In a lithium ion secondary battery having such a configuration, since the carbonate is stable to the oxidation and reduction of water and other organic solvents and can obtain a higher voltage, a larger energy density and a higher capacity can be obtained than for a 20 nickel-hydrogen battery, which is an water-based battery. Consequently, lithium ion secondary batteries are becoming widely spread as a secondary battery for power tools, laptop computers, mobile phones, video cameras, digital still cameras and the like. [0003] 25 Recently, lithium ion secondary batteries have started to spread into applications other than those mentioned above, even into industrial uses for electric vehicles, power storage and the like. Industrial secondary batteries need to have high capacity, high power output, and long life battery qualities. One of the battery qualities required in order to withstand high current is heat-release properties. 30 When a high current is applied, heat is generated. FIowevel; an excessive increase in battery temperature is laown to accelerate degradation of battery performance, and shorten battery life. Accordingly, how efficiently the heat generated by the battery can be released becomes important. This issue is now the subject of various studies. [0004] 5 For example, the following Patent Literature 1 discloses a configuration of a lithium ion battery for a vehicle, in which when four lithium ion batteries are stacked, a metal heat sink that has been subjected to an insulating treatment is arranged between each of the batteries, and the lithium ion batteries, the heat sink, and an end plate are clamped together by a clamping belt. I0 Citation List Patent Literature [OOOS] Patent Literature 1: JP 2004-227788A Summary of Invention Technical Problem [0006] However, in the configuration described in Patent Literature 1, the lithium 20 ion battery and the metal heat sink are separate parts. The stacking state is fixed by only the clamping force of the clamping belt, so that there is the problcm that the stacking state tends to fall apart. Further, there is also the problem that it is impossible to stack a large number of batteries. In addition, if the lithium ion battery is used for a long duration, the battery expands compared with its initial state. 25 The configuration described in Patent Literature 1 to counter such battery expansion suppresses expansion with a clamping force. However, for a lithium ion battery that has a laminate film exterior, if the clamping force is too strong, damage can be caused to the battery itself, so that an expansion countermeasure like that in Patent Literature 1 cannot be employed. 30 [0007] Therefore, it is an object of the present disclosure to provide a battery unit, a 3133 battery module, a power storage system, an electronic device, a power system, and an electric vehicle, that are capable of handling battery expansion while improving a heat release effect. Solution to Problem 5 [OOO8] In order to achieve the above-mentioned object, an embodiment of the present invention is a battery module including a plurality of stacked battery units. The battery unit is arranged in a manner that a face of a heat-transfer plate held in a battery support body formed from an insulating material and a main face of a battery 10 cell oppose each other. [O009] An embodiment of the present invention is a battery unit in which a battery support body which holds a hot-transfer plate, the battery support body being fonned from an insulating material, a face of the heat-tiansfer plate, and a main face of a 15 battery cell are arranged to oppose one another. [OO 101 An embodiment of the present invention, is a power storage system in which the above-described battery module is charged by a power generation device which generates power from renewable energy. 20 An embodiment of the present invention is a power storage system that includes the above-described battery module, in which the power storage system supplies power to an electronic device comlected to the battery module. An embodiment of the present invention is an electronic device co~ifigured to receive power supplied from the above-described battery module. 25 An embodiment of the present invention is an electric vehicle including a co~lversion device configured to receive power supplied froin the above-described battery module and convert the received power into driving power of a vehicle, and a control device configured to perf01111 information processing relating to vehicle control based on information about the battery module. 30 An embodiment of the present invention is a power system that has a power information transmittii~glreceivingu nit configured to transmitlreceive signals tolfrom other devices via a network, in which the power system is configured to control chargeldischarge of the battery module based on information received by the power information 5 An embodiment of the present invention is a power system configured to receive power supplied from the above-described battery module, or to supply power to the battery module from a power generation device or a power network Advantageous Effects of Invention 10 [OOll] According to the present disclosure, a heat-transfer plate is fixed to a battery support body, and each of the main faces of two battery cells are closely adhered to either side of the heat-transfer plate. Heat generated by the battery cells 1s transmitted to the heat-transfer plate. By making the heat-transfer plate externally 15 protrude from a side face of the battery support body, an external cooling module and the protruding portion of the heat-transfer plate can come into contact to release heat. Since both the heat-transfer plate and the battery cells are fixed to the battery support body, the attachment state of these parts is stable. Similarly, a battery module including such stacked battery units can also have a stable attachment state between 20 the heat-transfer plate and the battery cells. Brief Description of Drawings [OO12] [FIG. 11 FIG. 1 is a diagram illustrating six views of the overall configuration of an 25 embodiment of a battery module according to the present disclosure. [FIG 21 FIG 2 is a cross-sectional view of an embodiment of a battery module according to the present disclosure. [FIG. 31 FIG. 3 is a perspective view illustrating an overall configuration of an embodiment of a battery module according to the present disclosure. 30 [FIG. 41 FIG. 4 is diagram illustrating a configuration of a battery unit according to the present disclosure. [FIG. 51 FIG. 5 is perspective view of a battery unit according to the present disclosure. [FIG. 61 FIG. 6 is an exploded perspective view of a battery unit according to the present disclosure 5 [FIG. 71 FIG. 7 is an exploded view of a battery unit according to the present disclosure [FIG. 81 FIG. 8 is a schematic cross-sectional view of a battery unit according to the present disclosure. [FIG 91 FIG. 9 is a partial cross-sectional view of a battery unit according to the 10 present disclosure. [FIGS. 10A to IOD] FIGS. 10A to 10D are perspective views and partial crosssectional views of an exterior member iIlustrating an example of a battery cell that can be applied in the present disclosure. [FIGS. 11A and 11B] FIGS. 11A and 11B are perspective views illustrating a 15 stacking configuration of battery units according to the present disclosure. [FIGS. 12A and 12B] FIGS. 12A and 12B are perspective views illustrating a stacking configwation of battery units according to the present disclosure. [FIGS. 13A and 13B] FIGS. 13A and 13B are schematic cross-sectional views illustrating expansionicontraction of a battery cell in a battery unit stacking 20 configuration according to the present disclosure. [FIG. 141 FIG. 14 is a front view, a side view, a planar view, a partial cross-sectional view, and a perspective view illustrating an individual cell bus bar. [FIG. 151 FIG. 15 is a front view, a side view, a planar view, a partial cross-sectional view, and a perspective view illustrating an individual cell bus bar. 25 [FIG 161 FIG. 16 is a front view illustrating an individual cell bus bar. [FIGS. 17A to 17D] FIGS. 17A to 17D are font views and connection diagrams illustrating a connection portion of an individual cell bus bar. [FIGS. 18A to 18D] FIGS. 18A to 18D are font views and connection diagrams illustrating a couilection part of an individual cell bus bar 30 [FIGS. 19A to 19C] FIGS. 19A to 19C are font views and a connection diagram illustrating a connection portion of an individual cell bus bar. [FIG. 201 FIG. 20 is a font view illustrating attachment of a bus bar in a battery cell group. [FIG. 211 FIG. 21 is a schematic diagram illustrating an applied example of a battery module. 5 [FIG. 221 FIG. 22 is a schematic diagram illustrating another applied example of a battery module. I Description of Embodiments [0013] 10 Battery Module Schematic Configuration An embodiment of a battery module according to the present disclosure will now be described with reference to FIGS. 1, 2, and 3. FIG. 1 is a diagram illustrating six views (a front view, a right side view, a left side view, a bottom face view, a planar view, and a rear view) of a battery module 100. FIG 2 is a cross- 15 sectional view of the battery module 100. FIG. 3 is a perspective view of the battery module 100. [0014] The battery module 100 includes a battery cell goup 103 that is arranged between end plates 101 and 102, which serve as a first and a second regulating plate. 20 An intermediate plate 104 is inscrted in an inteimediate position of the battery cell group 103. Attachment tabs 105a and 105b are formed at a lower portion of the intermediate plate 104. The intermediate plate 104 between the endplates 101 and 102 is a plate made from a metal such as aluminum or iron. [00 151 25 The battery cell group 103 is a staclc formed from N-number of battery unrts configured from a plurality of battery cells each housed in a battery support body (hereinafter referred to as a "bracket"). Ln one embodiment, for example, two battery cells are housed in each bracket. The battery cell may be, for example, a Ilth~um ion secondary battery The bracket is a molded article formed from a 30 synthetrc resin. As illustrated in FIGS. 2 and 3, the battery cell group 103 is a staclc formed from 10 battery umts 20-1 to 20-10 (l.e., 20 battery cells). In cases where the individual battery cells do not need to be differentiated, the battery cells will be referred to simply as battery unit 20. [0016] A shaft 106 passes through holes formed in the endplates 101 and 102, the 5 intermediate plate 104, and the four comers of the battery cell group 103, and is secured by nuts 107 from either side. A heat-transfer plate 108 folded into an Lshape guided from each of the 10 brackets is exposed to the bottom face side of the battery cell group 103. This heat-transfer plate 108 is in contact with a cooling module (not shown). Heat generated by the battery cell is transmitted to the cooling 10 module and released. Further, terminals 109 and 110 for extracting power from the battery module are provided near the end plates 101 and 102, respectively. LOO1 71 A plate-like conductive member (hereinafter referred to as "cell bus bar") for connecting the two battery cells in the battery unit is attached to either side face of 15 each battery unit of the battery cell group 103. The cell bus bar is a conductive body formed by plating nickel on iron, for example, in a plate shape. Two types of cell bus bars are used. One type is a common cell bus bar 111 that commonly connects the two battery cells in each batteiy unit, and the other is an individual cell bus bar 112 for extracting from the terminals individually connected to both the 20 positive and the negative electrode tabs of the two battery cells. Note that, as described below, although there are two types of individual cell bus bar 112 (individual cell bus bars 112a and 112b), in cases where these two types do not need to be differentiated, they will be referred to simply as individual cell bus bar 112. [00 181 25 In addition, a second plate-like collductive member (hereinafter refelred to as "unit bus bar") 114 formed from aluminum or iron, for example, is used to connect between the battery units. The unit bus bar 114 is attached straddling a plurality of battery units so as to realize a desired battery connection. The common cell bus bar 111, the individual cell bus bar 112, and the unit bus bar 114 are fixed to a side face 30 of the bracket by a screw, for example [0019] Battery Unit The battery unit 20, which is the basic unit forming the battery cell group 103, will now be described. The battery cell may be, for example, a lithium ion secondary battery. A plurality of battery cells, for example, two, are housed in a 5 bracket to configure a battery unit. The bracket is a molded article formed from a synthetic resin. FIG. 4 is a front view, a right side view, a left side view, a bottom face view, and a planar view of the battery unit 20. FIG. 5 is a perspective view of the battery unit 20. FIG. 6 is an exploded perspective view of the battery unit 20. FIG. 7 is exploded view of the battery unit 20. FIG. 8 is a schematic cross-sectional 10 view of the battery unit 20. FIG. 9 is a partial cross-sectional view of the battery unit 20. [0020] The bracket 1, whch is formed from an insulating material (synthetic resin), has a fraine shape for housing the battery cells. A heat-transfer plate 2 (in FIGS. 1 15 to 3 illustrating the overall configuration of the battery module, the heat-transfer plate is denoted with the reference numeral 108) made of a metal such as aluminum is formed integrally with the bracket 1 by insert molding. Insert molding is a molding method for integrally foi~ninga resin and an insert article by filling an insert article (here, the heat-transfer plate 2) serving as an embedding target into a mold, 20 then injecting a resin into the molding machine, encasing the insert article with molten resin and solitlifying. [0021] The heat-transfer plate 2 is positioned at an aperture in the center of the bracket 1 to form a pasting face of the battery cell. Fui-ther; as illustrated in FIGS. 7 25 and 8, an edge portion of the heat-transfer plate 2 is folded in an almost L shape so as to protrude outwards from the bracket 1 and follow the side face of the bracket 1, thereby forming a folded portion 2a. The width of the folded portion 2a is slightly less than 1.5 times the width of the battery unit. Therefore, the tip of the folded portion 2a protrudes from the width of the battery unit. The folded portion 2a of the 30 heat-transfer plate 2 is in contact with the cooling face of the cooling module. The cooling module is a water-cooled or air-cooled cooling device. In an embodiment of the present disclosure, one edge of the heat-transfer plate 2 is folded iuto an L shape. However, the other edge of the heat-transfer plate 2 may also be similarly folded into an L shape so that it similarly protrudes outwards 5 from the bracket 1. In addition, the tip may be formed into a cross-sectional Tshape or H-shape that extends toward both sides. [0023] As illustrated in FIGS. 6 and 7, a main face of battery cells 4-1 aud 4-2 is closely adhered to the face of the heat-transfer plate 2 that is integral with the bracket 10 1 via a thermally conductive pressure-sensitive adhesive sheet 3-1 and 3-2, respectively. In cases where the battery cells do not need to be individually differentiated, the battery cells will be referred to battery cell 4. The battery cell 4 has a plate shape or a cube shape. The face having the greatest surface area among the surfaces of the battery cell is called the main face. 15 [0024] A positive and a negative electrode tab is guided from both side faces of the battery cells 4-1 and 4-2. Whether an electrode tab is positive or negative depends on the attachment direction of the battery cells 4-1 and 4-2 to the bracket 1. For example, as illustrated in FIG. 6, a positive electrode tab 5-1 of the battery cell 4-1 20 and a negative electrode tab 6-2 of the battery cell 4-2 protrude from the side face on one side of the bracket, and a negative electrode tab 6-1 of the battery ccll 4-1 and a positive electrode tab 5-2 of the battery cell 4-2 protrude from a side face on the other side of the bracket. [0025] 25 The common cell bus bar 11 1 is fixed by a screw 3 1 to one side face of the bracket 1, and the individual cell bus bar 112 is fixed by a screw 31 to the other side face of the bracket 1. The positive electrode tab 5-1 of the battery cell 4-1 and the negative electrode tab 6-2 of the battery cell 4-2 are joined by laser welding or the like to a tab joining plate of the common cell bus bar 11 1. The negative electrode 30 tab 6-1 of the battery cell 4-1 and the positive electrode tab 5-2 of the battery cell 4-2 are joined by laser welding or the like to a tab joining plate of the individual cell bus bar 112. A bus bar cover 113 formed from an insulating material is detachably provided so as to cover both the common cell bus bar 11 1 and the individual cell bus bar 112. [0026] 5 A connecting portion is formed in each of the four corners of the bracket 1. A hole 7 that the shaft 106 (refer to FIG. 1) passes through is formed in the thickness direction of the bracket 1 in each connecting portion. To form the holes 7, as illustrated in FIG. 9, a metal sleeve (also refelred to as a "collar") 8 is integrally formed with the bracket 1 by insert molding. Providing the metal sleeve 8 reduces 10 the effect of changes in the environmental temperature 'during expansion and contraction. [0027] If the metal sleeve 8 is not provided, this means that in a configuration in which the four comers are secured by the shaft 106, the resin pats of the bracket 1 15 contact each other, and are fixed by the shaft 106. If the environmental temperature changes, the shaft 106 and the bracket 1 expand (increase in temperature) or contract (decrease in temperature). Although the difference in the amount of expansionicontraction of the shaft 106 (metal) and the amount of expansionicontraction of the bracket 1 is sinall in a single battery unit, since a battery 20 module (battery cell group 103) is formed from many battery units stacked on each other, this difference increases. Consequently, if a large force is applied on the bracket 1, the bracket 1 may break. [0028] In contrast, by providing the metal sleeve 8, the battery units contact each 25 other at the end face of the metal sleeve 8. Therefore, in the battery module, the difference in the amount of expansior~lcontraction of the shaft 106 (metal) and the amount of expansionicontraction of the bracket 1 can be reduced. In addition, since the metal sleeve 8 has a higher limit against compression than the bracket 1, damage to the bracket 1 can be prevented. 30 [0029] Battery Cell Configuration FIG. 10A is a schematic diagram of the exterior of the battery cell 4 that can be used in the present disclosure. The battery cell 4 is a non-aqueous electrolyte battery, for example, a lithium ion secondary battery. FIG. 10B is a schematic diagram illustrating the configuration of the battery cell 4. It is noted that FIG. 10B 5 illustrates a coilfiguration for a case in which the bottom face and the top face of the battery cell 4 illustrated in FIG. 10A have been inverted. FIG. 10C is an exterior bottom face side of the battery cell 4. The battery cell 4 includes a battery element 11 and external cladding 12 that houses the battery element 11. The battery cell 4 has a first main face and a second main face. 10 [0030] The external cladding 12 is configured from a first external cladding portion 12A that houses the battery element 11, and a second external cladding portion 12B that functions as a lid for covering the battery element 11. It is preferred that the exterior cladding 12 and the battery element 11 are closely adhered. 15 [0031] The battery element 11 has' a laminate-type electrode structure in which a roughly rectangular positive electrode and a roughly rectangular negative electrode arranged opposing the positive electrode are alternately laminated with a separator interposed therebetween. Further, a positive electrode current collector exposed 20 portion electrically connected to each of a plurality of positive electrodes and a negative electrode clwrent collector exposed portion electrically connectctl to each of a plurality of negative electrodes are drawn out froin the battery element 11. A positive electrode tab 5 and a negative electrode tab 6 are connected to the positive electrode current collector exposed portion and the negative electrode current 25 collector exposed portion, respectively. [0032] Such a battery element 11 is cladded by the external cladding 12. The positive electrode tab 5 and the negative electrode tab 6 are guided to the outside of the battery cell 4 from a sealing portion of the external cladding 12. The external 30 claddiug 12 has a concave portiou 13 on at least one face, or on both faces. This concave portion 13 is formed by deep drawing in adva~~ceT. he battery element 11 is housed in this concave portion 13. In FIG. 108, the concave poition 13 is formed in the external first external cladding portion 12A that forms the external cladding 12, and the battery element 11 is housed in this concave portion 13. [0033] 5 Further, the second external cladding portion 12B is arranged so as to cover the aperture of the concave portion 13, and adhered is by welding or the like to the periphery of the aperture of the concave portion 13, thereby sealing the battery cell 4. The positive electrode tab 5 and the negative electrode tab 6 are guided out from two opposing directions. 10 [0034] The external cladding 12 is, for example, a flexible film. As illustrated in FIG. 10D, the external cladding 12 has a structure obtained by laminating, in order, a heat-sealing resin layer 14, a metal layer 15, a surface protective layer 16, with an adhesive layer interposed therebetween. It is noted that the face of the heat-sealing 15 resin layer 14 serves as the face on the side where the battery element 11 is housed. It is preferred that the surfaces of the heat-sealing resin layer 14 and the battery element I I are closely adhered. Examples of the material for the heat-sealing resin layer 14 include polypropylene (PP) and polyethylene (PE). Examples of the material for the metal layer include aluminuln alloy. Examples of the surface 20 protective layer 16 include nylon (Ny) and polyethylene terephthalate (PET). [0035] Specifically, for example, the external cladding 12 is configured from a rectangular aluminum laminate film obtained by pasting, in order, a polyethylene film, aluminum foil, and a nylon film. The external cladding 12 is configured so 25 that, for example, the polyethylene film side and the battery element 11 are arranged opposite each other, with their outer edge portions closely adhered to each other by welding or an adhesive. It is iloted that the external cladding 12 may be configured from a laminate film having some other structure, a polymer film of polypropylene and the like, or a metal film, instead of the above-described aluminum laminate film. 30 [0036] It is noted that the configuration of the battery cell that can be applied in the present disclosure is not limited to that described above. For cxample, a configuration may also be used in which a separator is formed in a long belt-like manner, folded back on itself in a switchbaclt fashion, and a positive electrode and a negative electrode sandwiched between the folded separator. In addition, a 5 configuration may be used in which a wound current collector to which a positive electrode lead and a negative electrode lead are attached is housed inside a film-lilce external cladding. [0037] Battery Unit Staclcing Configuration 10 For a vehicle requiring a high-power, high-capacity battery, as described above, the battery cell group 103 is configured by staclcing a plurality of battery units, and connecting the battery cells in series andlor parallel. In an embodiment of the present disclosure, heat generated by the respective battery units is led to an external cooling module by the heat-transfer plate 2. Therefore, to ensure a heat release 15 effect, the battery cell 4 and the heat-transfer plate 2 need to be closely adhered. [0038] On the other hand, since cell expansion increases in proportion to the initial thickness, the battery cell 4 needs to press against the heat-transfer plate without darnaging the battery cell in consideration of the cell expansion amount. From such 20 a point, in an embodiment of thc present disclosure, an elastic body for absorbing cell thickness expansion is interposed between battery units. [0039] For example, as illustrated in FIGS. 11A and 12A, the two batteiy units 20-1 and 20-2 are arranged so that the battery cells 4-1 and 4-2 respectively included 25 therein oppose each other. A cushion material 21 is placed as an elastic body in the space where the battery cells 4-1 and 4-2 oppose each other. The cushion material 21 is a thin plate-lilte material having roughly the same shape as the main faces of the battery cells 4-1 and 4-2. The cushion material 21 is formed from an elastic material that is deformed by pressure, and returns to its or~ginal shape when the 30 pressure 1s released. For example, a urethane material can be used. In addit~on, the cushion is prevented from fall~ngo ut by optionally providing a pressure-sensit~ve adhesive material on one or both faces of the cushion material 21. [0040] Further, as illustrated in FIGS. 11B and 12B, two battery units 20-1 and 20- 2 are stacked with the cushion material 21 interposed therebetween, and a 5 predetermined pressure is applied in the stacking direction with the shaft 106 and nuts 107. As described above, the battery cell 4 uses a laminate film as external cladding, which expands due to cycle degradation and degradation over time. By using the cushion material 21 and appropriately setting the pressure applied between the battery units, battery cell expansion can be dealt with while maintaining the heat 10 release effect obtained by the heat-transfer plate 2. [004 11 Setting of the pressure applied between the battery units will now be described with reference to the schematic diagram of FIG. 13. FIG 13A illustrates an initial stage, and FIG. 13B illustrates when the hattery cells 4-1 and 4-2 have 15 expanded. The battery units 20-1 and 20-2 are stacked with an interval T between them. The thickness of each battery cell at the initial stage is represented as Tc. A gap G across which the battery units 20-1 and 20-2 oppose each other is represented byG=T-2Tc. ZOO421 20 As illustrated in FIG. 138, when battery cells 4-1 and 4-2 expand so that the thiclcness of each bnttcry cell is Tc' (>Tc), a gap G' across which the battc~y units 20- 1 and 20-2 oppose each other is G' = T - 2Tc' (G'