JP2004047262A - Thin batteries and assembled batteries - Google Patents

Abstract

An object of the present invention is to improve a heat radiation effect of a battery.
A power generation element includes at least a metal layer and includes a battery outer casing that houses a power generation element, and a heat seal portion (outer peripheral edge) that houses and seals the power generation element. The electrode terminals 104 and 105 connected to the electrodes and the radiator 2 were provided, and the connection region 121 of the battery casings 106 and 107 and the first radiator 21 were thermally connected.
[Selection] Fig. 2

Description

[0001]
【Technical field】
The present invention relates to a thin secondary battery and a battery pack in which a power generation element is housed inside a battery exterior.
[0002]
[Background Art]
The internal temperature of the secondary battery rises due to Joule heat or the like generated at the time of charge / discharge. However, if the internal temperature of the battery rises excessively, the battery performance will be adversely affected, such as lowering the charge / discharge characteristics of the battery. On the other hand, there has been proposed a battery pack including a heat collecting plate that comes into contact with the battery and a heat pipe that radiates heat from the heat collecting portion (see JP-A-2002-134177, rear).
[0003]
However, providing a heat collecting plate in contact with each unit battery increases the volume and weight of the battery, lowers the output density, and hinders miniaturization and weight reduction of the battery.
[0004]
DISCLOSURE OF THE INVENTION
An object of the present invention is to efficiently dissipate heat generated in a battery without providing a heat collecting plate.
[0005]
According to the present invention, at least a metal layer, containing a power generation element and accommodating an outer peripheral edge of the battery exterior, an electrode terminal derived from the outer peripheral edge and connected to an electrode of the power generation element, A thin battery having a heat dissipation means thermally connected to a battery exterior is provided.
[0006]
In the present invention, since the heat radiating means is connected to the battery exterior housing the power generating element, the heat generated by charging and discharging is transmitted to the heat radiating means and radiated, so that the temperature of the power generating element housed by the battery exterior is increased. Can be suppressed.
[0007]
Thus, heat generated in the battery can be efficiently dissipated without providing a heat collecting plate.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
<First embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a plan view showing the entire thin battery according to the embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line BB of FIG. FIG. 1 shows one thin battery (unit battery), and an assembled battery having a desired voltage and capacity is formed by stacking a plurality of the thin batteries 10.
[0009]
First, the overall configuration of a thin battery 10 according to an embodiment of the present invention will be described with reference to FIGS. The thin battery 10 of the present embodiment is a lithium-based thin secondary battery, and as shown in FIG. 1, battery outer casings 106 and 107 are two sealed battery outer casings (an upper battery outer casing 106 and a lower battery outer casing 107). The upper battery exterior 106 and the lower battery exterior 107 house a power generation element 109 required for power generation, and are sealed by heat welding at a heat seal portion 108 on the outer peripheral edge of the housing portion. The positive terminal 104 and the negative terminal 105 are led out of the heat seal part 108. The heat seal portion 108 other than the heat seal portion 108 from which the positive electrode terminal 104 and the negative electrode terminal 105 are led out has a connection region 121 that is thermally connected to the heat radiating portion 2 (not shown). The connection regions 121 provided on the battery exteriors 106 and 107 function as a medium for transmitting the heat of the thin battery 10 to the heat radiating unit 2 as a heat radiating unit.
[0010]
The upper battery casing 106 and the lower battery casing 107 of this embodiment include at least a metal layer, and an aluminum foil intermediate layer corresponding to the metal layer, and ethylene acrylic acid formed inside the aluminum foil intermediate layer. Excellent electrical insulation such as polyamide resin and polyester resin formed on the inner layer made of a heat-fusible polymer such as copolymer (EAA), polyethylene and polypropylene, and the outer layer of the intermediate layer made of aluminum foil. It is a laminate film having a three-layer structure having an outer surface layer made of an insulating resin (Japanese Patent Publication No. 98 / 042,036). As the intermediate layer, in addition to the aluminum foil, a metal foil having excellent flexibility and strength such as a stainless steel foil can be adopted, and the type of the metal material is not limited.
[0011]
The connection regions 121 provided in the battery casings 106 and 107 may be provided with a thermal connection with a heat radiating portion 2 (not shown), and may be provided with a heat-welding resin layer. Is preferably in a state where the metal layer contained in is exposed. When the metal layer is exposed in the connection region 121, the metal layer may be exposed by peeling the outer resin layer of the three-layer laminate film, or when forming the three-layer laminate film, The metal layer may be exposed by not applying the corresponding outer resin layer.
[0012]
Next, the inside of the thin battery 10 wrapped in the battery exteriors 106 and 107 will be described with reference to FIG. As shown in FIG. 2, the thin battery 10 includes two positive plates 101, five separators 102, two negative plates 103, a positive terminal 104, a negative terminal 105, and an upper battery case 106. , The lower battery exterior 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 109. The number of the positive electrode plate 101, the separator 102, and the negative electrode plate 103 is not limited at all, and the power generating element 109 can be constituted by one positive electrode plate 101, three separators 102, and one negative electrode plate 104. . If necessary, the number of the positive electrode plate, the negative electrode plate, and the number of separators can be selected and configured.
[0013]
The positive electrode plate 101 constituting the power generation element 109 is formed by adding a conductive material such as carbon black and an adhesive such as an aqueous dispersion of polytetrafluoroethylene to a positive electrode active material such as a metal oxide in a weight ratio of, for example, 100%. : A mixture of 3:10 was applied to both sides of a metal foil such as an aluminum foil as a positive electrode current collector, dried, rolled, and then cut into a predetermined size. The mixing ratio of the aqueous dispersion of polytetrafluoroethylene is the solid content.
[0014]
Examples of the positive electrode active material include lithium composite oxides such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), and lithium cobaltate (LiCoO ₂ ), and chalcogenide (S, Se, Te) compounds. Can be.
[0015]
The negative electrode plate 103 constituting the power generation element 109 is formed of, for example, an amorphous carbon, a non-graphitizable carbon, a graphitizable carbon, or a negative electrode active material that occludes and releases lithium ions of a positive electrode active material, such as graphite. An aqueous dispersion of styrene-butadiene rubber resin powder as a precursor material for the organic fired body is mixed at, for example, a solid content ratio of 100: 5, dried, and then pulverized to carry carbonized styrene-butadiene rubber on the carbon particle surfaces. The main material is mixed with a binder such as an acrylic resin emulsion at a weight ratio of, for example, 100: 5, and the mixture is mixed with a metal foil such as a nickel foil or a copper foil as a negative electrode current collector. It is coated on both sides, dried, rolled, and then cut into a predetermined size.
[0016]
In particular, when amorphous carbon or non-graphitizable carbon is used as the negative electrode active material, the flatness of the potential during charge and discharge is poor, and the output voltage decreases with the amount of discharge, so it is not suitable for the power supply of communication equipment and office equipment. However, when used as a power source for an electric vehicle or the like, there is no sharp drop in output, which is advantageous.
[0017]
Further, the separator 102 of the power generation element 109 prevents short-circuit between the positive electrode plate 101 and the negative electrode plate 103 described above, and may have a function of retaining an electrolyte. The separator 102 is a microporous film made of, for example, a polyolefin such as polyethylene (PE) or polypropylene (PP). When an overcurrent flows, the heat generated by the separator 102 closes the pores of the film and cuts off the current. It also has
[0018]
Note that the separator 102 of the present invention is not limited to a single-layer film of polyolefin or the like, and may be a three-layer structure in which a polypropylene layer is sandwiched by a polyethylene layer, or a laminate of a polyolefin microporous film and an organic nonwoven fabric. . By forming the separator 102 into multiple layers, various functions such as a function of preventing an overcurrent, a function of retaining an electrolyte, and a function of maintaining the shape of the separator (improving rigidity) can be provided. Further, a gel electrolyte, an intrinsic polymer electrolyte, or the like can be used instead of the separator 102.
[0019]
The above-described power generating elements 109 are stacked such that the positive electrode plate 101 and the negative electrode plate 103 are alternately arranged from the top and in such an order that the separator 102 is located between the positive electrode plate 101 and the negative electrode plate 102. One separator 102 is stacked on each of the upper and lower parts. Each of the two positive plates 101 is connected to a metal foil positive terminal 104 via a positive current collector 104a, while the two negative plates 103 are connected to a negative current collector 105a. Is connected to the negative electrode terminal 105 also made of metal foil. Note that 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 aluminum and an aluminum alloy. Or stainless steel. In addition, both the positive-side current collector 104a and the negative-side current collector 105a of the present example are configured by extending an aluminum foil, a nickel foil, and a copper foil constituting the current collector of the positive electrode plate 104 and the negative electrode plate 105. However, the current collectors 104a and 105a can be formed of separate materials and components.
[0020]
The above-described power generation element 109, the positive-side current collector 104a, a part of the positive terminal 104, the negative-side current collector 105a, and a part of the negative terminal 105 are wrapped in battery exteriors 106 and 107, and the battery exteriors 106 and 107 are provided. Is injected into a space formed by a liquid electrolyte containing a lithium salt such as lithium perchlorate or lithium borofluoride as an organic liquid solvent, and then the outer peripheral edges 108 of the upper battery outer casing 106 and the lower battery outer casing 107 are thermally fused. It is sealed by a method such as wearing.
[0021]
Examples of the organic liquid solvent include ester solvents such as propylene carbonate (PC), ethylene carbonate (EC), and dimethyl carbonate (DMC). However, the organic liquid solvent of the present invention is not limited thereto. An organic liquid solvent obtained by mixing and preparing an ether-based solvent such as γ-butylactone (γ-BL), diethoxyethane (DEE) or the like with an ester-based solvent can also be used.
[0022]
As shown in the figure, the positive electrode terminal 104 is led out from one end of the sealed battery outer casings 106 and 107, and the upper battery outer casing 106 and the lower battery outer casing 107 have a thickness corresponding to the thickness of the positive electrode terminal 104. In order to maintain the sealing property in the thin battery 10, a sealing film made of polyethylene or polypropylene is provided at a portion where the positive electrode terminal 104 and the battery casings 106 and 107 are in contact with each other. It can also be interposed by a method such as heat fusion.
[0023]
Similarly, a negative electrode terminal 105 is led out from the other end of the sealed battery outer casings 106 and 107. Here, similarly to the positive terminal 104 side, the negative electrode terminal 105 and the battery outer casings 106 and 107 are connected. A seal film may be interposed in a portion where the contact is made. In any of the positive electrode terminal 104 and the negative electrode terminal 105, it is preferable that the seal film is formed of the same resin as the resin forming the battery casings 106 and 107 from the viewpoint of heat fusion.
[0024]
Subsequently, an assembled battery in which the thin batteries 10 are electrically connected and stacked will be described with reference to FIGS. 3 and 4. As shown in FIG. 2, the unit thin batteries 10 to be stacked include a cup-shaped exterior 106 having a concave shape for accommodating the power generation element 109, and a sheet-shaped exterior 107 covering the cup-shaped exterior 106. I have. 3 is a battery pair in which two unit thin batteries 10 are overlapped so that the flat sheet-shaped exterior 107 is opposed to each other and electrically connected in parallel, and further, the battery pairs are connected in series. , A battery pack in which eight unit thin batteries 10 are stacked. A first heat radiating member 21 as the heat radiating portion 2 is provided in a gap between the pair of battery pairs (thin battery 10). The first heat radiating member 21 is arranged along the edge of the heat seal portion 108 other than the heat seal portion 108 (outer peripheral edge) from which the electrode terminals 104 and 105 are led out, and is in contact with the connection region 121 of the battery exteriors 106 and 107. And are thermally connected to the battery exteriors 106 and 107.
[0025]
Here, the first heat radiating member 21 will be described with reference to FIG. FIG. 4 is a front view of the battery pack of FIG. As shown in FIG. 4, the first heat radiating member 21 is arranged to fill a gap between the unit thin batteries 10. The thickness of the heat sealing portion 108 is about the thickness of the sealed laminate sheet, and a step is formed between the heat sealing portion 108 and the portion where the power generation element 109 is accommodated. By disposing the first heat radiating member 21 on the thin heat seal portion 108 (outer peripheral edge) so as to fill the step, the stacked unit thin batteries 10 can be stabilized. The thickness of the first heat dissipating member 21 of the present embodiment was set to approximately twice (nd = 2d) the thickness d of the thin battery 10 (thickness of the power generation element housing portion). In the present embodiment, since the first heat radiating member 21 is disposed between the battery pair consisting of the two unit thin batteries 10, the distance between the heat seal portion 108 of the stacked thin batteries 10 and the heat seal portion 108 overlapping the thin battery 10 is small. Is twice as large as the thickness d. Thereby, the first heat radiating member 21 forms a gap (thickness of two thin batteries 10) between the battery pair including the two unit thin batteries 10 and the battery pair stacked on the battery pair. Can be filled. Incidentally, since the thin battery 10 of the present embodiment has a thickness of 4 mm, the thickness of the first heat radiation member 21 is set to 8 mm. Of course, when the unit thin batteries 10 are stacked without forming a pair, the thickness may be substantially the same as the thickness d of the thin potential 10 (nd = d).
[0026]
The first heat radiating member 21 is thermally connected to a connection region 121 provided in the heat seal portion 108 of the battery exteriors 106 and 107. Since the first heat radiating member 21 is interposed between the unit thin batteries 10 without any gap, the connection region 121 is sandwiched between the stacked first heat radiating members 21, and the connection region 121 and the first heat radiating member 21 are thermally connected. Connected. As described above, heat generated in the thin battery 10 due to charge / discharge or the like is conducted to the first heat dissipation member 21 via the connection regions 121 of the battery exteriors 105 and 106. The first heat radiating member 21 radiates heat transmitted from the thin battery 10 and keeps the temperature of the thin battery 10 constant.
[0027]
As shown in FIG. 3, the thin battery 10 of the present embodiment includes, in addition to the first heat dissipating member 21 connected to the connection region 121, the second heat dissipating members 22 and 23 thermally connected to the first heat dissipating member 21. And further provided. The second heat radiating members 22 and 23 constitute at least a part of a battery case that accommodates the plurality of thin batteries 10.
[0028]
In this assembled battery, first, eight unit thin batteries 10 are prepared, and a battery is formed by combining the two unit batteries 10 such that the flat sheet-shaped exterior 107 faces each other while securing electrical connection. The first heat radiating member 21 is joined to the heat seal portion 108 of the heat seal portion 108 of each unit thin battery 10 constituting the battery, from which the electrode terminals 104 and 105 are not led out. In the present embodiment, since the connection region 121 is a region where the metal layer is exposed, ultrasonic vibration is applied to ultrasonically join the first heat radiation member 21 and the connection region 121. For this ultrasonic bonding, a general ultrasonic bonding apparatus may be used. Vibration generated by the vibrating element, for example, vibration of 60 to 120 kHz is transmitted to the connection region 121 via vibration transmitting means, and the ultrasonic vibration is transmitted. The connection area 121 and the first heat radiating member 21 are connected using the frictional heat generated by the above. Of course, the connection region 121 may be subjected to heat welding by applying heat. When the connection region 121 is a region where the heat-fusible resin layer is exposed, the first heat radiation member 21 and the connection region 121 are fused by heating.
[0029]
In this way, the batteries in which the battery pair and the first heat dissipation member 21 are joined are stacked, and the battery pairs are joined together to form the assembled battery body. Further, the second heat radiating member 22 that covers the battery assembly from the side is joined to the first heat radiating member 21. When the first heat radiating member 21 and the second heat radiating member 22 are made of a metal material, the two members are joined by ultrasonic joining or heat welding. An adhesive or the like can also be used. When the first heat radiating member 21 and the second heat radiating member 22 are joined, the second heat radiating member 23 is joined so as to further cover the thin battery 10 from the top and bottom surfaces. A second heat radiating member (not shown) is attached so as to secure electrical connection between the electrode terminals 104 and 105 and cover the thin battery 10 from the electrode terminals 104 and 105 side. Thereby, the assembled battery is housed in the battery case including the heat dissipating members 21 to 23.
[0030]
As described above, the first heat radiating member 21 provided in the gap between the stacked unit thin batteries 10 is thermally connected to the second heat radiating member 22 that is in contact with the left and right side surfaces of the thin battery 10. Further, the first heat radiating member 21 and the second heat radiating member 22 are thermally connected to a second heat radiating member 23 which is in contact with the bottom surface of the upper surface of the thin battery 10. As described above, the heat generated in the thin battery 10 due to charging / discharging or the like is transmitted to the first heat radiating member 21 from the connection region 121 provided in the battery exteriors 106 and 106, and is radiated by the first heat radiating member 21. Since the heat is transmitted from the member 21 to the second heat radiating member 22 and further transmitted from the second heat radiating member 22 to the second heat radiating member 23 and radiated, the heat in the thin battery 10 is efficiently radiated without providing a heat collecting plate. Can be done. In particular, by forming at least a part of the first heat radiating member 21 and the second heat radiating members 22 and 23 from aluminum, stainless steel, or other metal having excellent heat conductivity, the heat conductivity is increased and the heat dissipation efficiency is improved. be able to. In this case, by exposing the metal layer of the connection region 121 to which the first heat radiating member 21 is thermally connected, heat is conducted between the metals having high thermal conductivity, and the efficiency is improved. A high heat radiation effect can be obtained.
[0031]
As described above, by thermally connecting the first heat radiating member 21 to the battery exteriors 106 and 107, heat in the thin battery 10 can be radiated without disposing a heat collecting plate. Further, the stacked thin batteries 10 are thermally connected to each other via at least one of the first heat radiating member 21 and the second heat radiating members 22 and 23, so that the stacked thin batteries 10 are formed. Variations in temperature between each other can be suppressed.
[0032]
Furthermore, since the heat dissipating members 21, 22, and 23 of the heat dissipating portion 2 of the present example are members constituting a battery case, there is no need to provide a heat dissipating portion in addition to the battery case. In addition, since the thin battery 10 is thermally connected to the battery case and other heat radiating portions, the thin battery 10 can be fixed to the battery case and other heat radiating portions, and the battery position such as maintaining the stacked state can be fixed. .
[0033]
In the present embodiment, the connection regions 121 provided on the battery exteriors 106 and 107 are directly connected to the battery pack case (heat dissipating members 21 to 23) as a heat radiating unit. It may be thermally connected to a radiator provided outside via a pipe.
[0034]
<Second embodiment>
A second embodiment will be described with reference to FIGS. The thin battery 10 of the second embodiment is different from the first embodiment in that it has an extension region 120 extending outward from the sealed heat seal portion 108 (outer peripheral edge). Here, different points will be mainly described, and description of points common to the first embodiment will be omitted.
[0035]
As shown in FIG. 5, the extending region 120 is formed on both the left and right sides of the heat seal portions 108 of the battery exteriors 106 and 107 other than the heat seal portion 108 from which the positive terminal 104 and the negative terminal 105 are led out. It extends outward. The extended region 120 may be provided on at least one of the upper battery outer casing 106 and the lower battery outer casing 107, and is formed as a part of a sheet constituting the upper battery outer casing 106 and / or the lower battery outer casing 107. You. The extended region 120 of the present embodiment is provided on a flat lower battery case 107 (having no recess formed therein for accommodating the power generation element 109). Are cut at the end of the heat seal portion 108. The reason why the extension region 120 is provided only in the lower battery exterior 107 is to ensure workability such as formation of a concave shape in the upper battery exterior 106 and accommodation of battery elements. Of course, the extension regions 120 may be provided on both the upper battery exterior 106 and the lower battery exterior 107. In this case, the extension region 120 of the upper battery exterior 106 and the extension region 120 of the lower battery exterior are welded, the heat seal portion 108 can be made wider, and the sealing property of the power generation element 109 is improved. .
[0036]
In each extension region 120, two connection regions 121 are provided at predetermined target positions around the housed power generation element 109. The position where the connection region 121 is provided is not particularly limited, but is provided at the end of the extension region 120 in this example. The connection region 121 functions as a connection portion for being thermally connected to the first heat dissipation member 21 included in the heat dissipation portion. The length of the extending connection region 121 is not particularly limited, and can be determined as appropriate according to the number of stacked unit thin batteries 10, the size of the battery case, and the like. As shown in the figure, the main body portion having the heat seal portion 108 as the outer peripheral edge has an extended area 120 of 140 (horizontal (R) 140 mm and vertical (P ) 60 mm.
[0037]
The connection region 121 provided in the extension region 120 may be in a state in which the heat-welding resin layer is exposed, as in the connection region of the first embodiment, or may be included in the battery casings 106 and 107. The exposed metal layer may be in an exposed state. As a method of exposing the resin layer and a method of exposing the metal layer, the method described in the first embodiment can be used.
[0038]
FIG. 6 shows an assembled battery in which eight thin batteries 10 of the present embodiment are stacked. In this battery pack, a battery pair is formed from two thin batteries 10 as in the first embodiment, and four battery pairs are stacked. The difference from the first embodiment (FIG. 3) is that an extension region 120 extending outward from the heat seal portion 108 is provided, and a connection region 121 thermally connected to the first heat radiation portion 21 extends. This is a point included in the region 120. In the connection region 121 of the present embodiment, the aluminum metal layer is exposed, and the connection region 121 is in contact with the first heat dissipation member 21 made of an aluminum metal material. The metal layer of the connection region 121 and the first heat radiating member 21 are joined by ultrasonic joining. The two extended regions 120 forming a battery pair in which two flat batteries 10 are opposed to the flat (not formed with a recess for accommodating the power generation element 109) lower battery exterior 107 are overlapped, and the extended regions 120 are connected. Ultrasonic vibration is applied to the welding spot provided on the region 121 to perform welding. Of course, the connection region 121 may be subjected to heat welding by applying heat.
[0039]
By providing the extension region 120 in this manner, the heat seal portion 108 can be made wider and the power generation element 109 can be securely sealed. Further, since the extension region 120 is provided, the degree of freedom of connection of the thin battery 10 is increased, so that it is possible to respond to various forms of electrical connection of the assembled battery, and a wide variety of connection of the assembled battery is provided. can do. The heat applied in this welding is transmitted from the connection region 121 to the entire extension region 120, and is efficiently radiated in the wide and thin extension region 120, so that the temperature of the power generation element 109 increases. Can be prevented.
[0040]
The embodiments described above are described for facilitating the understanding of the present invention, and are 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.
[Brief description of the drawings]
FIG. 1 is a plan view showing an entire thin battery according to a first embodiment of the present invention.
FIG. 2 is a sectional view taken along line BB in FIG.
FIG. 3 is a perspective view showing an assembled battery in which thin batteries according to the first embodiment of the present invention are stacked.
FIG. 4 is a front view of the battery pack shown in FIG. 3;
FIG. 5 is a plan view showing the entire thin battery according to a second embodiment of the present invention.
FIG. 6 is a perspective view showing an assembled battery in which thin batteries according to a second embodiment of the present invention are stacked.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Thin battery 101 ... Positive electrode plate 102 ... Separator 103 ... Negative electrode terminal 104 ... Positive electrode terminal 105 ... Negative electrode terminal 106 ... Upper battery exterior 107 ... Lower battery exterior 109 ... Power generation element 2 ... Heat dissipation part (heat dissipation means)
21: first heat dissipation member, 22, 23: second heat dissipation member)

Claims (13)

A battery exterior including at least a metal layer and containing a power generation element and having an outer peripheral edge sealed therein,
An electrode terminal derived from the outer peripheral edge and connected to an electrode of the power generating element,
A thin battery having a heat radiating means thermally connected to the battery exterior. 2. The thin battery according to claim 1, wherein the battery exterior has a connection area thermally connected to the heat radiating means on an outer edge of the outer edge other than an outer edge from which the electrode terminal is led out. 3. The battery exterior has an extending region extending outward from an outer peripheral edge other than the outer peripheral edge from which the electrode terminal is led out of the sealed outer peripheral edge,
The thin battery according to claim 1, wherein the extension region includes a connection region thermally connected to the heat radiating unit. The thin battery according to claim 2, wherein the connection region includes a region where the metal layer of the battery exterior is exposed. The positive electrode active material of the power generation element contains a lithium component,
The thin battery according to any one of claims 1 to 4, wherein the negative electrode active material of the power generation element includes a carbon-based material. A power generation element is accommodated in a battery exterior including at least a metal layer, and an electrode terminal connected to an electrode of the power generation element electrically connects and stacks a plurality of thin batteries derived from an outer peripheral edge of the battery exterior. Battery.
Further comprising a heat radiating means thermally connected to a battery exterior of the thin battery,
The battery pack according to claim 1, wherein the heat radiating unit includes a first heat radiating member provided in a gap between the stacked thin batteries. The battery pack according to claim 6, wherein the first heat radiation member is thermally connected to an outer peripheral edge of the outer peripheral edge other than an outer peripheral edge from which the electrode terminal is led out. The battery exterior has an extending region extending outward from an outer peripheral edge other than the outer peripheral edge from which the electrode terminal is led out of the sealed outer peripheral edge,
The battery pack according to claim 6, wherein the first heat radiating member is thermally connected to at least a part of the extension region. 9. The battery pack according to claim 7, wherein at least a region of the extension region in contact with the first heat radiation member includes a region where a metal layer of the battery exterior is exposed. The assembled battery according to any one of claims 6 to 9, wherein the first heat radiation member has a thickness substantially n times (n is a natural number) the thickness of the thin battery. The heat radiating unit further includes a second heat radiating member thermally connected to the first heat radiating member,
The battery pack according to any one of claims 6 to 10, wherein the second heat radiating member forms at least a part of a battery case that houses the battery. The assembled battery according to claim 6, wherein at least a part of the heat radiating unit is made of a metal material. The positive electrode active material of the power generation element contains a lithium component,
The battery pack according to any one of claims 6 to 12, wherein the negative electrode active material of the power generation element includes a carbon-based material.

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