JPWO2011125505A1 - Electricity storage device - Google Patents

Abstract

An electricity storage device 600 according to the present invention includes an electricity storage cell 10 in which an electricity storage unit having a positive electrode, a negative electrode, and an electrolyte is accommodated in an exterior body, and a heat sink 30 provided on the outer surface of the exterior body of the energy storage cell 10; And a housing 602 that houses the electricity storage 10 cell and the heat sink 30, and the heat sink 30 is in contact with the inner surface 603 of the housing 602.

Description

  The present invention relates to an electricity storage device.

  A sealed storage cell having a structure in which a storage unit including a positive electrode and a negative electrode is housed in an exterior body together with an electrolyte and sealed is known. As a power storage unit of a sealed power storage cell, a form in which positive electrodes and negative electrodes are alternately stacked via separators, or a form in which positive electrodes and negative electrodes are wound through separators is adopted. In such a power storage unit, the number of stacked layers and the number of windings are increased to increase the energy and capacity of the sealed power storage cell.

  The sealed storage cell as described above may accumulate heat when it is repeatedly charged and discharged within a short period of time, and the performance may deteriorate due to the high temperature. In particular, in recent years, the amount of heat generation has increased with the demand for higher energy in sealed type storage cells.

  For example, in the technique disclosed in Japanese Patent Application Laid-Open No. 2009-272048, a sealed secondary battery using a laminate film as a battery container is fixed to a metal heat radiating plate to improve heat dissipation. It is improving.

  However, as the energy and the storage capacity increase, the amount of heat generated by charging / discharging increases, the storage cell becomes larger, and heat tends to be accumulated inside the storage cell. Therefore, it is necessary to dissipate heat more efficiently than before.

  One of the objects according to some aspects of the present invention is to provide an electricity storage device with good heat dissipation.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
One aspect of the electricity storage device according to the present invention is:
A power storage unit having a positive electrode, a negative electrode, and an electrolyte, and a power storage cell housed in an exterior body;
A heat sink provided on the outer surface of the outer package of the electricity storage cell;
A housing for housing the storage cell and the heat sink;
Including
The heat sink is in contact with the inner surface of the housing.

[Application Example 2]
In application example 1,
A plurality of the storage cells and the heat sink are stacked,
The plurality of power storage cells can be electrically connected.

[Application Example 3]
In application example 2,
The storage cell and the heat sink are alternately stacked,
Among the heat sinks adjacent to each other through the storage cell,
One of the heat sinks is in contact with the first inner surface of the housing,
The other heat radiating plate can be in contact with a second inner surface different from the first inner surface of the housing.

[Application Example 4]
In application example 2,
Among the plurality of storage cells, the first storage cell, the second storage cell, the third storage cell, and the fourth storage cell are stacked in this order,
The heat dissipation plate is disposed between the first power storage cell and the second power storage cell, and between the third power storage cell and the fourth power storage cell,
The second power storage cell and the third power storage cell may be separated from each other through a gap.

[Application Example 5]
In any one of Application Examples 1 to 4,
A first fixing member and a second fixing member connected to the inner surface of the housing;
The power storage cell may be fixed by being sandwiched between the first fixing member and the second fixing member.

[Application Example 6]
In application example 5,
The exterior body is configured by joining a first exterior film and a second exterior film,
The first exterior film and the second exterior film are:
A flat outer surface formed by bulging by housing the power storage unit in the exterior body;
An inclined outer surface that is continuous with the flat outer surface and is inclined with respect to the flat outer surface;
Have
The first fixing member is provided from the flat outer surface to the inclined outer surface of the first exterior film,
The second fixing member may be provided from the flat outer surface to the inclined outer surface of the second exterior film.

[Application Example 7]
In Application Example 6,
The heat sink is provided on the flat outer surface of the first outer film and the flat outer surface of the second outer film,
The first fixing member and the heat radiating plate provided on the flat outer surface of the first exterior film do not overlap,
The second fixing member and the heat radiating plate provided on the flat outer surface of the second exterior film may not overlap each other.

[Application Example 8]
In Application Example 6,
The heat sink is provided on the flat outer surface of the first outer film and the flat outer surface of the second outer film,
The first fixing member and the heat dissipation plate provided on the flat outer surface of the first exterior film overlap with each other,
The second fixing member and the heat radiating plate provided on the flat outer surface of the second exterior film may overlap each other.

[Application Example 9]
In any one of Application Examples 5 to 8,
The thickness of the first fixing member and the thickness of the second fixing member may be larger than the thickness of the heat radiating plate.

[Application Example 10]
In any one of Application Examples 1 to 9,
The material of the housing may be aluminum.

[Application Example 11]
In any one of Application Examples 1 to 10,
A positive electrode terminal provided on the exterior body and electrically connected to the positive electrode;
A negative electrode terminal provided on the exterior body and electrically connected to the negative electrode;
Further including
The heat radiating plate may not overlap the positive electrode terminal and the negative electrode terminal.

[Application Example 12]
In any one of Application Examples 1 to 11,
The power storage unit may be a lithium ion capacitor.

  According to the electricity storage device of the present invention, the heat sink is in contact with the inner surface of the housing. Thereby, the electrical storage device which concerns on this invention can transmit the heat | fever which generate | occur | produced in the electrical storage cell to a housing | casing via a heat sink, and can be radiated from a housing | casing. Therefore, the electricity storage device according to the present invention can have high heat dissipation.

FIG. 1 is a perspective view schematically showing the electricity storage device according to the present embodiment. FIG. 2 is a diagram schematically illustrating the electricity storage device according to the present embodiment. FIG. 3 is a diagram schematically showing the electricity storage device according to the present embodiment. FIG. 4 is a diagram schematically showing a part of the electricity storage device according to the present embodiment. FIG. 5 is a diagram schematically showing a part of the electricity storage device according to the present embodiment. FIG. 6 is a diagram schematically showing a part of the electricity storage device according to the present embodiment. FIG. 7 is a diagram schematically showing a part of the electricity storage device according to the first modification of the present embodiment. FIG. 8 is a diagram schematically showing a part of the electricity storage device according to the first modification of the present embodiment. FIG. 9 is a diagram schematically illustrating a part of the electricity storage device according to the second modification of the present embodiment. FIG. 10 is a diagram schematically illustrating a part of the electricity storage device according to the second modification example of the present embodiment. FIG. 11 is a diagram schematically illustrating an electricity storage device according to a third modification of the present embodiment. FIG. 12 is a diagram schematically illustrating an electricity storage device according to a third modification of the present embodiment. FIG. 13 is a diagram schematically illustrating an electricity storage device according to a fourth modification of the present embodiment. FIG. 14 is a diagram schematically illustrating an electricity storage device according to a fourth modification of the present embodiment. FIG. 15 is a diagram schematically illustrating an electricity storage device according to a fifth modification of the present embodiment. FIG. 16 is a diagram schematically illustrating an electricity storage device according to a fifth modification example of the present embodiment. FIG. 17 is a diagram schematically illustrating a part of the electricity storage device according to the fifth modification example of the present embodiment. FIG. 18 is a perspective view schematically showing a part of the electricity storage device according to the fifth modification of the present embodiment. FIG. 19 is a diagram schematically illustrating an electricity storage device according to a fifth modification of the present embodiment. FIG. 20 is a diagram schematically illustrating an electricity storage device according to a fifth modification of the present embodiment. FIG. 21 is a diagram schematically illustrating an electricity storage device according to a sixth modification of the present embodiment.

  Preferred embodiments of the present invention will be described below with reference to the drawings.

1. Power Storage Device First, the power storage device according to the present embodiment will be described. FIG. 1 is a perspective view schematically showing an electricity storage device 600 according to the present embodiment. FIG. 2 is a diagram schematically showing the electricity storage device 600 according to this embodiment. FIG. 3 is a diagram schematically showing the electricity storage device 600 according to the present embodiment, as viewed from the III direction of FIG. 2 and 3 are perspective views of the housing 602 of FIG.

  As shown in FIGS. 1 to 3, the power storage device 600 includes a housing 602, a power storage cell 10, a positive electrode terminal 20 and a negative electrode terminal 22 provided on the power storage cell 10, a radiator plate 30, and external terminals 604. 606.

  The storage cell 10 and the heat sink 30 are housed in a housing 602. The number of power storage cells 10 and heat dissipation plates 30 is not particularly limited, but in the example illustrated in FIG. 2, four power storage cells 10 and five heat dissipation plates 30 are provided. The storage cells 10 and the heat dissipation plates 30 are alternately stacked. More specifically, the power storage cell 10a, the power storage cell 10b, the power storage cell 10c, and the power storage cell 10d are provided in this order, and the heat dissipation plate 30 is disposed so as to sandwich each power storage cell.

  In the example illustrated in FIG. 2, the plurality of power storage cells 10 are connected in series. Thereby, the power storage device 600 can increase the output voltage. More specifically, the negative electrode terminal 22 of the energy storage cell 10a and the positive electrode terminal 20 of the energy storage cell 10b are electrically connected, and the negative electrode terminal 22 of the energy storage cell 10b and the positive electrode terminal 20 of the energy storage cell 10c are Electrically connected, the negative electrode terminal 22 of the electricity storage cell 10c and the positive electrode terminal 20 of the electricity storage cell 10d are electrically connected. The electrical connection between the positive electrode terminal 20 and the negative electrode terminal 22 is performed by, for example, a conductive wiring 608. Although not shown, the plurality of power storage cells 10 may be connected in parallel. The output current can be increased by connecting them in parallel.

  In the example shown in FIG. 2, four power storage cells 10 are provided, but the number thereof is not particularly limited. For example, one power storage cell 10 may be provided, and four or more power storage cells may be provided. 10 may be provided, and the number can be set in a timely manner according to the target output voltage or output current.

  The shape of the housing 602 is not particularly limited as long as the storage cell 10, the terminals 20 and 22, and the heat sink 30 can be accommodated therein. However, in the example illustrated in FIG. 1, the housing 602 is a quadrangular prism (a rectangular parallelepiped). is there. An example of the material of the housing 602 is aluminum. Thereby, the heat generated in the storage cell 10 can be radiated from the housing 602 via the heat radiating plate 30 (details will be described later).

  An air cooling unit 610 and an exhaust unit 612 may be formed in the housing 602. In the example shown in FIG. 1, the air cooling unit 610 is formed on the bottom surface (lower surface) of the housing 602, and the exhaust unit 612 is formed on the upper surface (surface facing the bottom surface) of the housing 602. It is desirable that the air cooling unit 610 be disposed so that all of the plurality of heat sinks 30 can be cooled. In the example shown in FIG. 1, two air-cooling units 610 and two exhaust units 612 are formed, but the numbers are not particularly limited. More specifically, the air cooling unit 610 is a fan for sending air to the heat sink 30 or a heat sink (not shown) thermally connected to the heat sink 30, and the exhaust unit 612 is outside the housing 602. It is a through-hole for exhausting air. Thereby, the heat sink thermally connected to the heat sink 30 or the heat sink 30 can be cooled, and the heat dissipation can be improved.

  The external terminals 604 and 606 are provided so as to extend from the inside to the outside of the housing 602. In the example illustrated in FIG. 2, the external terminal 604 is electrically connected to the positive electrode terminal 20 of the storage cell 10 a through a wiring 608. The external terminal 606 is electrically connected to the negative electrode terminal 22 of the storage cell 10d through a wiring 608. Examples of the material of the external terminals 604 and 606 include aluminum, copper, and nickel.

  As shown in FIG. 3, the heat sink 30 is in contact with the inner surface (side surface) 603 of the housing 602. In the example illustrated in FIG. 3, the heat dissipation plate 30 is in contact with the two inner surfaces 603 of the housing 602. Thereby, the heat generated in the storage cell 10 can be transmitted to the housing 602 via the heat radiating plate 30 and radiated from the housing 602. For example, the heat dissipation can be further improved by cooling the housing 602. That is, the heat sink 30 can also function as a heat pipe for conducting heat generated by the power storage cell 10 (power storage unit 18) to the housing 602. Therefore, the electricity storage device 600 can have high heat dissipation.

  Next, the structure of the electrical storage cell 10, the terminals 20 and 22, and the heat sink 30 will be described in more detail. FIG. 4 is a plan view schematically showing a part of the electricity storage device 600 according to the present embodiment. FIG. 5 is a diagram schematically showing a part of the electricity storage device 600 according to this embodiment, and is a diagram seen from the V direction in FIG. 4. 4 and 5 show, for convenience, one storage cell 10, a set of positive electrode terminal 20 and negative electrode terminal 22 provided in the storage cell 10, and one heat sink 30 provided in the storage cell 10. , Illustrated.

  As shown in FIGS. 4 and 5, the power storage cell 10 can include an exterior body 12 and a power storage unit 18.

  The exterior body 12 accommodates the power storage unit 18 therein. It can be said that the power storage unit 18 is hermetically sealed by the exterior body 12. The exterior body 12 can have a first exterior film 14 and a second exterior film 16. The exterior body 12 may be configured by joining the first exterior film 14 and the second exterior film 16 by, for example, thermocompression bonding.

  The first exterior film 14 can have a flat inner surface 14 a that is an inner surface of the exterior body 12. The second exterior film 16 can have a flat inner surface 16 a that is an inner surface of the exterior body 12. The flat inner surfaces 14 a and 16 a may be in contact with the power storage unit 18 accommodated in the exterior body 12. It can be said that the flat inner surfaces 14 a and 16 a are surfaces formed by swelling of the exterior body 12 by accommodating the power storage unit 18. That is, the planar shape of the flat inner surfaces 14 a and 16 a may be determined by the swelling of the exterior body 12 by the power storage unit 18. The planar shape of the flat inner surfaces 14a, 16a is preferably rectangular, and may be square or rectangular. In the example shown in FIG. 4, the planar shape of the flat inner surfaces 14a and 16a is a rectangle.

  The first exterior film 14 can have a flat outer surface 14b which is the outer surface of the exterior body 12 and is a surface opposite to the flat inner surface 14a of the first exterior film 14. The second exterior film 16 can have an outer surface of the exterior body 12 and a flat outer surface 16 b that is a surface opposite to the flat inner surface 16 a of the second exterior film 16. The planar shapes of the flat outer surfaces 14b and 16b may be the same as the planar shapes of the flat inner surfaces 14a and 16a, respectively. It can be said that the flat outer surfaces 14 b and 16 b are surfaces formed by swelling of the exterior body 12 by accommodating the power storage unit 18.

  As the exterior films 14 and 16, for example, a laminate film is used. The laminate film is composed of, for example, a metal layer and a first resin layer and a second resin layer that sandwich the metal layer. Examples of the material of the metal layer include aluminum. Examples of the material of the first resin layer include polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), and polyamide resin. Examples of the material of the second resin layer include ethylene vinyl acetate copolymer resin (EVA) or olefin resins such as polyethylene and polypropylene.

  Thus, by using the film-shaped exterior films 14 and 16, for example, compared with the case where the hard exterior body (metal can etc.) which consists of metals etc. is used, size reduction and weight reduction of the electrical storage cell 10 are achieved. Can do.

  The power storage unit 18 is accommodated in the exterior body 12. The power storage unit 18 includes a positive electrode, a negative electrode, and an electrolyte. Further, the power storage unit 18 may include a separator that separates the positive electrode and the negative electrode. The positive electrode, the negative electrode, and the separator can have a sheet shape. The power storage unit 18 may have a wound structure in which a positive electrode and a negative electrode arranged via a separator are wound. The power storage unit 18 may have a stacked structure in which positive electrodes and negative electrodes are alternately stacked via separators. Specific examples of the power storage unit 18 include a lithium ion capacitor, a lithium ion battery, and an electric double layer capacitor. Note that a detailed description of the positive electrode, the negative electrode, the electrolyte, and the separator constituting the power storage unit 18 will be described later.

  The thickness T of the storage cell 10 is preferably 4 mm or more and 20 mm or less. When the thickness of the storage cell is in the above range, for example, when the storage unit built in the storage cell has a stacked structure, the number of stacked positive and negative electrodes can be increased. Further, when the power storage unit incorporated in the power storage cell has a wound structure, the number of turns of the positive electrode and the negative electrode can be increased. As a result, the configuration of the power storage device having a large energy capacity intended in the present invention is facilitated.

  If the power storage unit becomes larger in order to increase the energy capacity and the thickness of the power storage cell becomes larger than 4 mm, the heat generated inside the power storage unit due to charging / discharging tends to be accumulated inside the power storage cell, and the efficiency to the outside Heat dissipation becomes difficult. As a result, the temperature inside the storage cell tends to increase as it leads to gas generation. However, even when the thickness of the storage cell 10 is increased in order to obtain large energy, it is possible to efficiently dissipate heat by providing the heat sink 30 in contact with the inner surface 603 of the housing 602 as in the present application. . For example, when the storage cell 10 has a thickness T of 8 mm, a lithium ion capacitor having an energy capacity of 1000 F or more can be secured. In this case, despite the large amount of heat generated from the power storage unit 18, in the power storage device 600 of the present invention, the heat generated inside the power storage cell 10 is efficiently radiated to the outside by the heat radiating plate 30 and the housing 602. be able to.

  Note that the thickness T of the storage cell 10 is, for example, the thickness of the storage cell 10 in a state of being accommodated in the exterior body 12 when the storage unit 18 has a wound structure. Further, when the power storage unit 18 has a stacked structure, for example, it is the size (length) in the stacking direction of the power storage cells 10 in a state of being accommodated in the exterior body 12. As described above, the power storage unit 18 may be in contact with the flat inner surfaces 14 a and 16 a of the exterior films 14 and 16. Therefore, the thickness T of the electricity storage cell 10 may be the distance between the flat outer surface 14b and the flat outer surface 16b.

  The positive electrode terminal 20 and the negative electrode terminal 22 are provided through the exterior body 12, as shown in FIG. The positive electrode terminal 20 and the negative electrode terminal 22 extend from the inside to the outside of the exterior body 12 in a state where the hermeticity of the exterior body 12 is maintained. The arrangement of the positive terminal 20 and the negative terminal 22 is not particularly limited. In the example shown in FIGS. 4 and 5, the positive terminal 20 extends from the left end (one end) of the exterior body 12, and the negative terminal 22 is the right end (the other end) of the exterior body 12. It extends from. The positive terminal 20 is electrically connected to the positive electrode of the power storage unit 18. The negative terminal 22 is electrically connected to the negative electrode of the power storage unit 18. Examples of the material of the positive electrode terminal 20 include aluminum. Examples of the material of the negative electrode terminal 22 include copper and nickel.

  The heat sink 30 is provided on the outer surface of the exterior body 12 as shown in FIG. In the example shown in FIG. 5, the heat sink 30 is provided in contact with the flat outer surface 14b. Although not shown, the heat sink 30 may be provided in contact with the flat outer surface 16b. The heat sink 30 may be provided so as to cover the entire flat outer surface 14b or the flat outer surface 16b. Thereby, heat dissipation can be improved.

  As shown in FIG. 4, in a plan view (for example, when viewed from the thickness direction of the heat radiating plate 30), the exterior body 12 is disposed, for example, inside the outer periphery of the heat radiating plate 30. That is, the area of the heat sink 30 is larger than the area of the exterior body 12 in plan view. Thereby, the surface area of the heat sink 30 can be increased, and heat dissipation can be improved. The positive electrode terminal 20 and the negative electrode terminal 22 are disposed so as to protrude outward from the outer periphery of the heat dissipation plate 30 in plan view. Thereby, the connection between the terminals 20 and 22 and the external wiring (not shown) can be facilitated, and a current can be easily obtained from the positive terminal 20.

  Examples of the material of the heat radiating plate 30 include aluminum, iron, copper, or an alloy mainly containing any one of these metals from the viewpoint of thermal conductivity. Of these metals, aluminum is particularly preferable from the viewpoint of weight reduction.

  Although the shape of the heat sink 30 is not specifically limited, In the example shown to FIG. 4 and FIG. 5, it is flat form. Although not shown, the heat dissipation plate 30 may have irregularities on its surface. Thereby, the surface area of the heat sink 30 can be increased, and heat dissipation can be improved.

  The thickness of the heat sink 30 is preferably 10 μm or more and 300 μm or less, and more preferably 50 μm or more and 200 μm or less.

  The heat radiating plate 30 can radiate the heat generated by the power storage unit 18. Moreover, the heat sink 30 can diffuse the heat generated by the power storage unit 18 uniformly throughout the power storage unit 18 and suppress local temperature rise. For example, when the calorific value at the central portion of the power storage unit 18 is larger than the calorific value at the end portion, the heat radiation plate 30 can make the heat generation uniform.

  Although the method of installing the heat sink 30 on the exterior body 12 is not particularly limited, a method of bonding the surface of the heat sink 30 and the outer surface of the exterior body 12 is used. More specifically, such as heat-fusible resin (ethylene vinyl acetate copolymer resin, olefin resin, etc.) and adhesive (hot melt adhesive, moisture curable adhesive, pressure sensitive adhesive, etc.) A method of bonding using an adhesive having high thermal conductivity can be exemplified. Further, the thermal conductivity can be further improved by mixing an inorganic filler such as boron nitride or an organic filler such as epoxy into the adhesive. Therefore, in the present invention, the configuration in which such a bonding agent is interposed between the heat radiating plate 30 and the outer package 12 is also included in the example of the configuration in which the heat radiating plate 30 is provided in contact with the outer surface of the outer package 12. . Alternatively, the heat radiating plate 30 and the outer package 12 may be heat-welded or may be pressure-bonded by a pressing method. Or you may make the heat sink 30 and the exterior body 12 contact with a suitable jig | tool (not shown). In addition, when using an adhesive agent, in order to improve heat dissipation, it is preferable that an adhesive agent does not exist except an adhesive surface, and an adhesive agent exists only in an adhesive surface.

  Next, the internal structure of the storage cell 10 will be described. 6 is a cross-sectional view showing a part of the electricity storage device 600 according to the present embodiment, and is a cross-sectional view schematically showing the internal structure (of the outer package 12) of the electricity storage cell 10 shown in FIG. In addition, in FIG. 6, illustration of the heat sink 30 is abbreviate | omitted for convenience.

  As shown in FIG. 6, the power storage unit 18 includes the electrode laminate 5 and an electrolytic solution (not shown) accommodated in the exterior body 12.

  The electrode laminate 5 is immersed in the electrolytic solution. The electrode laminate 5 can include a positive electrode 1, a negative electrode 2, and a separator 4. The positive electrode 1, the negative electrode 2, and the separator 4 have a sheet shape. In the illustrated example, the electrode laminate 5 is laminated in the order of the negative electrode 2, the positive electrode 1, the negative electrode 2, the positive electrode 1, and the negative electrode 2 from the flat inner surface 16 a of the second exterior film 16, and between the poles and The separator 4 is interposed between the pole and the exterior body. In the electrode laminate 5, the positive electrode 1 and the negative electrode 2 are connected in parallel.

  The number of positive electrodes 1 and negative electrodes 2 is not particularly limited. Moreover, the form of the electrode laminated body 5 is not limited to the example of illustration, For example, the winding structure body formed by laminating | stacking a laminated sheet by laminating | stacking a positive electrode, a negative electrode, and a separator may be sufficient. .

  As shown in FIG. 6, the positive electrode 1 includes a positive electrode current collector 1a and a positive electrode active material layer 1b. As the positive electrode current collector 1a and the positive electrode active material layer 1b, a known material related to an electricity storage device can be used. Examples of the material of the positive electrode current collector 1a include aluminum, nickel, and titanium. The positive electrode current collector 1a may be a porous metal foil made of the aforementioned material. The thickness of the positive electrode current collector 1a is not particularly limited, and is, for example, 20 μm or more and 50 μm or less. The positive electrode current collector 1 a is connected to the positive electrode terminal 20 through the positive electrode lead 6.

  The positive electrode active material layer 1b is formed on the positive electrode current collector 1a. The positive electrode active material layer 1b may be formed on both sides of the positive electrode current collector 1a as shown in FIG. 6, or may be formed only on one side. Although the thickness of the positive electrode active material layer 1b is not specifically limited, For example, they are 60 micrometers or more and 90 micrometers or less.

  The positive electrode active material layer 1b is prepared by, for example, dispersing a powdery positive electrode active material, a conductive additive, and a binder (binder) in an aqueous solvent or an organic solvent to prepare a slurry, and collecting the slurry into a positive electrode current collector It is formed by applying to the surface of the body and drying.

When the power storage unit 18 is a lithium ion capacitor or an electric double layer capacitor, the positive electrode active material is a material that can reversibly carry an anion such as hexafluorophosphate (PF ₆ ⁻ ) or tetrafluoroborate (BF ₄ ⁻ ). is there. More specifically, examples of the positive electrode active material include activated carbon and a polyacene-based material (PAS) that is a heat-treated product of an aromatic condensation polymer.

  When the power storage unit 18 is a lithium ion battery, the positive electrode active material is a material that can reversibly store lithium ions. More specifically, examples of the positive electrode active material include lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, iron phosphate compounds, and mixtures thereof.

  The “lithium-nickel-based oxide” is an oxide having lithium (Li) and nickel (Ni) as constituent metal elements, and the main (first) transition metal element is Ni. In addition, a composition containing at least one metal element other than Li and Ni (that is, at least one of a transition metal element and a typical metal element other than Li and Ni) in a smaller proportion (atomic ratio) than Ni. It is meant to include oxides. Examples of the metal element include Co, Al, Mn, Cr, Fe, V, Mg, Ti, Zr, Nb, Mo, W, Cu, Zn, Ga, In, Sn, La, and Ce. These metal elements may be used alone or in combination of two or more. The same applies to lithium cobalt oxides and lithium manganese oxides.

  As the conductive assistant, for example, a carbon material such as carbon black (such as acetylene black) or a metal powder such as nickel powder can be used.

  Examples of the binder include celluloses such as methyl cellulose (MC), carboxymethyl cellulose (CMC), and ethyl cellulose (EC), polyvinyl alcohol, polyacrylate, polyalkylene oxide (for example, polyethylene oxide), polyvinylidene fluoride (PVDF), Fluorine polymers such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), and organic polymers such as styrene butadiene block copolymer (SBR) can be used.

  As shown in FIG. 6, the negative electrode 2 includes a negative electrode current collector 2a and a negative electrode active material layer 2b. For the negative electrode current collector 2a and the negative electrode active material layer 2b, a known material related to an electricity storage device can be used. Examples of the material of the negative electrode current collector 2a include copper, nickel, and titanium. The negative electrode current collector 2a may be a porous metal foil made of the aforementioned material. Although the thickness of the negative electrode collector 2a is not specifically limited, For example, it is 20 micrometers or more and 50 micrometers or less. The negative electrode current collector 2 a is connected to the negative electrode terminal 22 through the negative electrode lead 7.

  The negative electrode active material layer 2b is formed on the negative electrode current collector 2a. The negative electrode active material layer 2b may be formed on both sides of the negative electrode current collector 2a as shown in FIG. 6, or may be formed only on one side. Although the thickness of the negative electrode active material layer 2b is not specifically limited, For example, they are 60 micrometers or more and 90 micrometers or less.

  The negative electrode active material layer 2b is prepared by, for example, dispersing a powdered negative electrode active material, a conductive additive, and a binder (binder) in an aqueous solvent or an organic solvent to prepare a slurry, It is formed by applying to the surface of the body and drying.

  When the electricity storage unit 18 is a lithium ion capacitor or a lithium ion battery, the negative electrode active material is a material that can reversibly store lithium ions. More specifically, examples of the negative electrode active material include natural graphite, mesocarbon microbead (MCMB) highly oriented graphite (HOPG), hard carbon, and soft carbon.

  When the power storage unit 18 is an electric double layer capacitor, the negative electrode active material is a material that can reversibly carry lithium ions, for example. More specifically, examples of the negative electrode active material include activated carbon.

  In addition, as a conductive support agent and a binder, the material enumerated by description of a positive electrode can be used.

  For the separator 4, a porous material that is durable against the electrolyte, the positive electrode active material, and the negative electrode active material can be used. For the separator 4, a known material related to the electricity storage device can be used. More specifically, as the separator 4, a nonwoven fabric made of cellulose, rayon, polyethylene, polypropylene, aramid resin, amideimide, polyphenylene sulfide, polyimide, or the like, a porous film, or the like can be used. Although the thickness of the separator 4 is not specifically limited, For example, they are 20 micrometers or more and 50 micrometers or less. The separator 4 can isolate the positive electrode 1 and the negative electrode 2 from each other. Further, the separator 4 can infiltrate the electrolyte. Note that when the power storage unit 18 uses a solid electrolyte as the electrolyte, the positive electrode 1 and the negative electrode 2 are not short-circuited without using the separator 4, and therefore the separator 4 can be omitted.

The electrolyte is, for example, a nonaqueous electrolyte. The non-aqueous electrolyte may be, for example, a liquid non-aqueous electrolyte containing a non-aqueous organic solvent as a main component, or may be a gel or solid electrolyte. For example, propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane, γ-butyrolactone, tetrahydrofuran, 1,3-dioxolane, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl acetate, methyl formate LiPF ₆ , LiBF ₄ , LiClO ₄ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiN (CF) may be added to any solvent selected from non-aqueous organic solvents such as ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ may be used as an electrolyte having a composition in which one or more lithium salts such as ₃ salt are dissolved. The concentration of the lithium salt in the electrolyte is, for example, 0.5 mol / L or more and 3 mol / L or less.

  According to the electricity storage device 600 according to the present embodiment, the heat sink 30 is in contact with the inner surface 603 of the housing 602. Thereby, the electricity storage device 600 can transmit the heat generated in the electricity storage cell 10 to the housing 602 via the heat dissipation plate 30 and dissipate the heat from the housing 602. Therefore, the electricity storage device 600 can have high heat dissipation.

  Furthermore, since the power storage device 600 according to the present embodiment has high heat dissipation, the power storage cell 10 is applied particularly effectively when a lithium ion capacitor having a large capacity and a large calorific value due to charge / discharge is used as the power storage cell 10. be able to.

2. Next, an electricity storage device according to a modification of the present embodiment will be described with reference to the drawings. Hereinafter, in the power storage device according to the modification of the present embodiment, members having the same functions as those of the constituent members of the power storage device 600 according to the present embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

2.1. First, a power storage device according to a first modification of the present embodiment will be described with reference to the drawings. FIG. 7 is a plan view schematically showing a part of the electricity storage device 300 according to the first modification of the present embodiment. FIG. 8 is a diagram schematically showing a part of the electricity storage device 300 according to the first modification of the present embodiment, and is a diagram seen from the VIII direction of FIG. 7 corresponds to FIG. 4, and FIG. 8 corresponds to FIG.

  In the example of the electricity storage device 600, as shown in FIG. 4, the exterior body 12 is disposed inside the outer periphery of the heat sink 30 in a plan view, and a part of the heat sink 30 and a part of the terminals 20 and 22 overlap. It was. On the other hand, in the electrical storage device 300, the heat sink 30 and the terminals 20 and 22 do not overlap in plan view as shown in FIG. That is, the heat sink 30 is separated from the terminals 20 and 22 in plan view.

  For example, when the temperature of the energy storage cell rises due to repeated charge and discharge of the energy storage cell and the temperature inside the energy storage cell rises above the heat resistance limit of the material, the electrolyte or the like may decompose and gas may be generated. And the internal pressure of an electrical storage cell rises with the gas, and an electrical storage cell may deform | transform. Furthermore, the heat sink may be deformed following the deformation of the storage cell. When the heat radiating plate is deformed and the heat radiating plate is in contact with the terminal, a short circuit may occur between the positive terminal and the negative terminal. However, according to the electricity storage device 300, contact between the heat dissipation plate 30 and the terminals 20 and 22 can be prevented even when the heat dissipation plate 30 is deformed.

2.2. Next, an electricity storage device according to a second modification of the present embodiment will be described with reference to the drawings. FIG. 9 is a plan view schematically showing an electricity storage device 400 according to a second modification of the present embodiment. FIG. 10 is a diagram schematically showing an electricity storage device 400 according to the second modification of the present embodiment, and is a diagram seen from the X direction of FIG. 9 corresponds to FIG. 4, and FIG. 10 corresponds to FIG.

  In the example of the electricity storage device 100, as shown in FIGS. 4 and 5, the positive electrode terminal 20 extends from one end of the outer package 12, and the negative terminal 22 extends from the other end of the outer package 12. It was. On the other hand, in the electricity storage device 400, as shown in FIGS. 9 and 10, both the terminals 20 and 22 extend from one end (for example, the right end).

  In addition, the heat sink 30 and the terminals 20 and 22 do not need to overlap in plan view as shown in FIG. Thereby, contact with the heat sink 30 and the terminals 20 and 22 can be prevented.

2.3. Next, an electricity storage device according to a third modification of the present embodiment will be described with reference to the drawings. FIG. 11 is a diagram schematically showing an electricity storage device 700 according to a third modification of the present embodiment, and corresponds to FIG. FIG. 12 is a diagram schematically showing an electricity storage device 700 according to a third modification of the present embodiment, and is a diagram seen from the XII direction of FIG.

  In the electricity storage device 700, as shown in FIG. 11, the heat radiating plates 30 are alternately in contact with the inner surface 603 (for example, the upper surface or the lower surface) of the housing 602. That is, one of the heat sinks 30 that are adjacent to each other via the storage cell 10 is in contact with the first inner surface 603a (for example, the upper surface) of the housing 602, and the other heat sink 30 is It is in contact with a second inner surface 603b (for example, the lower surface) different from the first inner surface 603a. In the example shown in FIG. 11, the heat sink 30 sandwiched between the power storage cell 10a and the power storage cell 10b, and the heat sink 30 sandwiched between the power storage cell 10c and the power storage cell 10d are in contact with the first inner surface 603a. The heat sink 30 sandwiched between the power storage cell 10b and the power storage cell 10c, and the heat sink 30 at both ends are in contact with the second inner surface 603b. As a result, the heat is dispersed throughout the housing 602 without being concentrated on a part of the housing 602, and the heat can be efficiently radiated.

  Furthermore, the heat sink 30 may be in contact with the inner surface (side surface) of the housing 602 as shown in FIG. That is, the heat sink 30 may be in contact with the three inner surfaces 603 of the housing 602. Thereby, heat can be more uniformly conducted to the housing 602.

  In addition, although not shown in figure, the heat sink 30 may be connected with cooling mechanisms, such as a chiller unit. Also with such a form, the heat dissipation of the electrical storage device 700 can be improved.

2.4. Next, an electricity storage device according to a fourth modification of the present embodiment will be described with reference to the drawings. FIG. 13 is a diagram schematically showing an electricity storage device 800 according to a fourth modification of the present embodiment, and corresponds to FIG. FIG. 14 is a diagram schematically showing an electricity storage device 800 according to the fourth modification of the present embodiment, and is a diagram seen from the XIV direction of FIG.

  In the example of the power storage device 600, as shown in FIG. 2, a power storage cell 10a, a power storage cell 10b, a power storage cell 10c, and a power storage cell 10d are provided in this order, and the heat dissipation plate 30 is arranged so as to sandwich each power storage cell. It was. On the other hand, in the electrical storage device 800, as shown in FIG. 13, the heat sink 30 is provided only between the electrical storage cell 10a and the electrical storage cell 10b and between the electrical storage cell 10c and the electrical storage cell 10d. In the electricity storage device 800, the electricity storage cell 10b and the electricity storage cell 10c are provided apart from each other through a gap.

  According to the electricity storage device 800, for example, when gas is generated in the electricity storage cell 10 as compared with the example of the electricity storage device 600, the electricity storage cell 10 is easily deformed because there is a gap between the electricity storage cells 10 ( Can swell). Therefore, the power storage device 800 can have high reliability. If the electricity storage cell cannot be deformed despite the generation of gas in the electricity storage cell, the internal pressure of the electricity storage cell is greatly increased, and a problem may occur.

2.5. Next, an electricity storage device according to a fifth modification of the present embodiment will be described with reference to the drawings. FIG. 15 is a diagram schematically showing an electricity storage device 900 according to a fifth modification of the present embodiment, and corresponds to FIG. FIG. 16 is a diagram schematically showing an electricity storage device 900 according to a fifth modification of the present embodiment, and is a diagram seen from the XVI direction of FIG. FIG. 17 is a diagram schematically illustrating a part of an electricity storage device 900 according to a fifth modification of the present embodiment. FIG. 18 is a perspective view schematically showing a part of an electricity storage device 900 according to an eighth modification of the present embodiment. In FIG. 17, for convenience, one power storage cell 10, terminals 20 and 22 provided in the power storage cell 10, a heat sink 30 provided in the power storage cell 10, and a fixing member provided in the power storage cell 10. Only 40 is shown. In FIG. 18, only one power storage cell 10, terminals 20 and 22 provided in the power storage cell 10, and a fixing member 40 provided in the power storage cell 10 are illustrated for convenience.

  The electrical storage device 900 has the fixing member 40 as shown in FIGS. The fixing member 40 is provided on the outer surface of the exterior body 12, for example, avoiding the heat sink 30. That is, the fixing member 40 and the heat sink 30 do not overlap. In the example shown in FIG. 17, the heat sink 30 is provided in the center part of the flat outer surfaces 14b and 16b. The fixing member 40 is provided from the flat outer surface 14b to the inclined outer surface 14c that is continuous with the flat outer surface 14b and is inclined with respect to the flat outer surface 14b, avoiding the central portion of the flat outer surface 14b. Furthermore, the fixing member 40 is provided from the flat outer surface 16b to the inclined outer surface 16c that is continuous with the flat outer surface 16b and is inclined with respect to the flat outer surface 16b, avoiding the central portion of the flat outer surface 16b. In the illustrated example, four fixing members 40 are provided for one storage cell 10.

  For example, as shown in FIG. 17, the storage cell includes a fixing member 40 (first fixing member 40a) on the first exterior film 14 side and a fixing member 40 (second fixing member 40b) on the second exterior film 16 side. The storage cell 10 can be fixed in the housing 602 with the 10 interposed therebetween. More specifically, the first fixing member 40 a is provided from the flat outer surface 14 b to the inclined outer surface 14 c of the first exterior film 14. The second fixing member 40b is provided from the flat outer surface 16b to the inclined outer surface 16c of the second exterior film 16. As shown in FIG. 18, the fixing member 40 can have a bulge portion 42. In the bulge portion 42, a portion (flat outer surface 14b, 16b, etc.) formed by the bulge of the exterior body 12 (power storage cell 10) by accommodating the power storage unit 18 can be accommodated. Thereby, the electrical storage cell 10 can be fixed stably.

  As the installation method of the fixing member 40 and the outer package 12, a heat-fusible resin (ethylene vinyl acetate copolymer resin, olefin resin, etc.) or an adhesive (hot melt adhesive, moisture curable adhesive, pressure sensitive) A method of bonding using an adhesive having a high thermal conductivity such as an adhesive can be exemplified. Further, an inorganic filler such as boron nitride or an organic filler such as epoxy may be mixed into the adhesive.

  The fixing member 40 is connected to the inner surface 603 of the housing 602 and can fix the storage cell 10 in the housing 602. As a material of the fixing member 40, for example, aluminum, iron, copper, or an alloy mainly containing any one of these metals can be given.

  A method for connecting the fixing member 40 and the housing 602 is not particularly limited. For example, the screw hole 44 (see FIG. 18) of the fixing member 40 is fixed to the inner surface 603 of the housing 602 with a screw. It may be fixed by welding, or may be performed using the adhesives listed as the installation method of the fixing member 40 and the exterior body 12.

  The rigidity of the fixing member 40 may be larger than the rigidity of the heat sink 30. Thereby, the electrical storage cell 10 can be stably fixed. For example, as shown in FIG. 19, the rigidity of the fixing member 40 can be made larger than the rigidity of the heat sink 30 by making the thickness of the fixing member 40 larger than the thickness of the heat sink 30. In the example shown in FIG. 15, the adjacent heat storage cells 10 share one heat sink 30. However, in the example shown in FIG. 19, two heat sinks 30 are provided in one power storage cell 10. Yes.

  In the example shown in FIGS. 15 and 19, four power storage cells 10 are provided, but the number is not particularly limited. For example, one power storage cell 10 may be provided, and four or more power storage cells 10 may be provided. The number of storage cells 10 may be provided, and the number can be set in a timely manner according to the target output voltage or output current.

  According to the electricity storage device 900, the electricity storage cell 10 can be stably fixed in the housing 602 by the fixing member 40. Therefore, the power storage device 900 can have high reliability.

  Furthermore, in the electricity storage device 900, the rigidity of the fixing member 40 can be made larger than the rigidity of the heat sink 30 by making the thickness of the fixing member 40 larger than the thickness of the heat sink 30. As a result, even when gas is generated in the power storage cell 10 and the power storage cell 10 is deformed, the power storage cell 10 is stably fixed by the fixing member 40 having a large rigidity, and the heat dissipation plate 30 has a low rigidity. 10 deformations can be followed. For example, a heat sink with high rigidity may not be able to follow the deformation of the storage cell, and the contact between the storage cell and the heat sink may be insufficient. The heat sink may be peeled off from the storage cell. Therefore, heat dissipation may be reduced. According to the electricity storage device 900, such a problem can be solved, and the heat storage cell 10 can be stably fixed while having high heat dissipation. In the example shown in FIGS. 15 and 17, since the fixing member 40 and the heat radiating plate 30 do not overlap, the fixing member 40 does not prevent the heat radiating plate 30 from being deformed. 10 deformations can be followed.

  In the present invention, “rigidity” refers to the degree to which an object resists deformation when an external force is applied to the object to cause deformation. That is, the smaller the rigidity, the easier the object is to deform (bend easily).

  In addition, as shown in FIG. 20, the power storage device 900 may include a heat sink 30 between the fixing member 40 and the power storage cell 10. That is, a part of the fixing member 40 and a part of the heat radiating plate 30 may overlap each other. Thereby, it can suppress more reliably that a heat sink peels from an electrical storage cell.

2.6. Next, an electricity storage device according to a sixth modification of the present embodiment will be described with reference to the drawings. FIG. 21 is a diagram schematically showing an electricity storage device 1000 according to the sixth modification example of the present embodiment, and corresponds to FIG. Hereinafter, the power storage device 1000 according to the sixth modification example of the present embodiment will be described mainly regarding differences from the power storage device 900 according to the fifth modification example of the present embodiment.

  In the example of the electricity storage device 900, as shown in FIG. 15, four fixing members 40 are provided for one electricity storage cell 10. On the other hand, in the electricity storage device 1000, as shown in FIG. 21, two fixing members 40 are provided for one electricity storage cell 10. More specifically, two power storage cells 10 are provided with the heat dissipation plate 30 interposed therebetween, and further two fixing members 40 are provided with the power storage cell 10 interposed therebetween.

  According to the electricity storage device 1000, for example, when the gas is generated in the electricity storage cell 10, the electricity storage cell 10 can be easily deformed (expanded) as compared with the example of the electricity storage device 900. If the electricity storage cell cannot be deformed despite the generation of gas in the electricity storage cell, the internal pressure of the electricity storage cell is greatly increased, and a problem may occur.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, it is possible to appropriately combine each embodiment and each modification. Further, for example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 1 Positive electrode, 2 Negative electrode, 4 Separator, 5 Electrode laminated body, 6 Positive electrode lead, 7 Negative electrode lead, 10 Storage cell, 12 Exterior body, 14 1st exterior film, 16 2nd exterior film, 18 Electrical storage unit, 20 Positive electrode terminal, 22 negative electrode terminal, 30 heat sink, 40 fixing member, 42 bulge portion, 44 screw hole, 300 power storage device, 400 power storage device, 600 to 1000 power storage device, 602 housing, 603 inner surface, 604 external terminal, 606 external terminal, 608 Wiring, 610 Air cooling part, 612 Exhaust part

Claims (12)

A power storage unit having a positive electrode, a negative electrode, and an electrolyte, and a power storage cell housed in an exterior body;
A heat sink provided on the outer surface of the outer package of the electricity storage cell;
A housing for housing the storage cell and the heat sink;
Including
The heat radiating plate is an electric storage device in contact with an inner surface of the casing. In claim 1,
A plurality of the storage cells and the heat sink are stacked,
The power storage device, wherein the plurality of power storage cells are electrically connected. In claim 2,
The storage cell and the heat sink are alternately stacked,
Among the heat sinks adjacent to each other through the storage cell,
One of the heat sinks is in contact with the first inner surface of the housing,
The other heat radiating plate is in contact with a second inner surface different from the first inner surface of the housing. In claim 2,
Among the plurality of storage cells, the first storage cell, the second storage cell, the third storage cell, and the fourth storage cell are stacked in this order,
The heat dissipation plate is disposed between the first power storage cell and the second power storage cell, and between the third power storage cell and the fourth power storage cell,
The power storage device, wherein the second power storage cell and the third power storage cell are separated from each other via a gap. In any one of Claims 1 thru | or 4,
A first fixing member and a second fixing member connected to the inner surface of the housing;
The electricity storage device, wherein the electricity storage cell is fixed by being sandwiched between the first fixing member and the second fixing member. In claim 5,
The exterior body is configured by joining a first exterior film and a second exterior film,
The first exterior film and the second exterior film are:
A flat outer surface formed by bulging by housing the power storage unit in the exterior body;
An inclined outer surface that is continuous with the flat outer surface and is inclined with respect to the flat outer surface;
Have
The first fixing member is provided from the flat outer surface to the inclined outer surface of the first exterior film,
The said 2nd fixing member is an electrical storage device provided in the said 2nd exterior film from the said flat outer surface to the said inclination outer surface. In claim 6,
The heat sink is provided on the flat outer surface of the first outer film and the flat outer surface of the second outer film,
The first fixing member and the heat radiating plate provided on the flat outer surface of the first exterior film do not overlap,
The electricity storage device, wherein the second fixing member and the heat radiating plate provided on the flat outer surface of the second exterior film do not overlap. In claim 6,
The heat sink is provided on the flat outer surface of the first outer film and the flat outer surface of the second outer film,
The first fixing member and the heat dissipation plate provided on the flat outer surface of the first exterior film overlap with each other,
The power storage device, wherein the second fixing member and the heat radiating plate provided on the flat outer surface of the second exterior film overlap each other. In any one of Claims 5 thru | or 8,
The thickness of the said 1st fixing member and the thickness of the said 2nd fixing member are electrical storage devices larger than the thickness of the said heat sink. In any one of Claims 1 thru | or 9,
The electricity storage device, wherein the housing is made of aluminum. In any one of Claims 1 thru | or 10,
A positive electrode terminal provided on the exterior body and electrically connected to the positive electrode;
A negative electrode terminal provided on the exterior body and electrically connected to the negative electrode;
Further including
The heat radiating plate is an electricity storage device in which the positive electrode terminal and the negative electrode terminal do not overlap. In any one of Claims 1 thru | or 11,
The electricity storage device, wherein the electricity storage unit is a lithium ion capacitor.

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