Patent Application
20240291079
The present invention relates to an electrical storage device, a heat transfer material, and a packaging.
Patent Document 1 discloses an example of an electrical storage device. In this electrical storage device, an electrode assembly is sealed in a bag formed of a laminate film. The laminate film includes a water vapor-impermeable layer formed of a material containing a metal such as aluminum. Therefore, ingress of water vapor and the like into the bag is suppressed.
If an electrode assembly generates heat in the electrical storage device, a part of the heat is transferred to a metal forming the water vapor-impermeable layer and released to the outside. Therefore, an excessive rise in temperature of the electrode assembly is suppressed. The thickness of the water vapor-impermeable layer may be further increased for more suitably suppressing a rise in temperature of the electrode assembly. However, since the water vapor-impermeable layer is formed of a material containing a metal, the productivity of the laminate film may be deteriorated if the thickness of the water vapor-impermeable layer is increased.
An object of the present invention is to provide an electrical storage device, a heat transfer material and a packaging which enable more suitably suppressing an excessive rise in temperature of an electrode assembly.
An electrical storage device according to a first aspect of the present invention includes: an electrode assembly; an outer packaging including an exterior film that seals the electrode assembly; and a heat transfer material attached to at least a part of a surface of the outer packaging, in which the exterior film includes at least a base material layer, an exterior barrier layer, and a heat-sealable resin layer, the exterior barrier layer is formed of a material containing a metal, the heat transfer material includes a heat transfer layer formed of a material containing a metal, and a thickness of the heat transfer layer is equal to or larger than a thickness of the exterior barrier layer.
An electrical storage device according to a second aspect of the present invention is the electrical storage device according to the first aspect, in which the outer packaging includes a first surface, and a second surface having an area larger than that of the first surface, and the heat transfer material is attached to at least the second surface.
An electrical storage device according to a third aspect of the present invention is the electrical storage device according to the first or second aspect, in which the heat transfer material is formed in a cover shape.
An electrical storage device according to a fourth aspect of the present invention is the electrical storage device according to any one of the first to third aspects, in which the outer packaging includes a cooling surface cooled by a cooling mechanism, and the heat transfer material is attached to at least a part of a portion of a surface of the outer packaging other than the cooling surface so as to expose the cooling surface.
An electrical storage device according to a fifth aspect of the present invention is the electrical storage device according to any one of the first to fourth aspects, in which a thickness of the exterior barrier layer is 100 μm or less.
An electrical storage device according to a sixth aspect of the present invention is the electrical storage device according to any one of the first to fifth aspects, in which the heat transfer material includes a base material layer laminated on the heat transfer layer.
An electrical storage device according to a seventh aspect of the present invention includes: an electrode assembly; an outer packaging including an exterior film that seals the electrode assembly; and a heat transfer material attached to the outer packaging so as to expose at least a part of a surface of the outer packaging, in which the exterior film includes at least a base material layer, an exterior barrier layer, and a heat-sealable resin layer, the exterior barrier layer is formed of a material containing a metal, and the heat transfer material includes a heat transfer layer formed of a material containing a metal.
A heat transfer material according to an eighth aspect of the present invention is a heat transfer material attached to a surface of an outer packaging of an electrical storage device including an electrode assembly, and the outer packaging including an exterior film that seals the electrode assembly, in which the heat transfer material includes a heat transfer layer formed of a material containing a metal.
A heat transfer material according to a ninth aspect of the present invention is the heat transfer material according to the eighth aspect, in which the exterior film includes an exterior barrier layer formed of a material containing a metal, and a thickness of the heat transfer layer is equal to or larger than a thickness of the exterior barrier layer.
A heat transfer material according to a tenth aspect of the present invention is the heat transfer material according to the ninth aspect, in which the outer packaging includes a first surface, and a second surface having an area larger than that of the first surface, and is attached to at least the second surface.
A heat transfer material according to an eleventh aspect of the present invention is the heat transfer material according to any one of the eighth to tenth aspects, in which the heat transfer material is formed in a cover shape.
A heat transfer material according to a twelfth aspect of the present invention is the heat transfer material according to any one of the eighth to eleventh aspects, in which the outer packaging includes a cooling surface cooled by a cooling mechanism, and the heat transfer material is attached to at least a part of a portion of a surface of the outer packaging other than the cooling surface so as to expose the cooling surface.
A heat transfer material according to a thirteenth aspect of the present invention is the heat transfer material according to any one of the tenth to twelfth aspects citing the ninth aspect, in which a thickness of the exterior barrier layer is 100 μm or less.
A heat transfer material according to a fourteenth aspect of the present invention is the heat transfer material according to any one of the eighth to thirteenth aspects, in which the heat transfer material includes a base material layer laminated on the heat transfer layer.
A packaging according to a fifteenth aspect of the present invention includes: an exterior film for sealing an electrode assembly; and a heat transfer material attached to at least a part of a surface of the outer packaging, in which the exterior film includes at least a base material layer, an exterior barrier layer, and a heat-sealable resin layer, the exterior barrier layer is formed of a material containing a metal, the heat transfer material includes a heat transfer layer formed of a material containing a metal, and a thickness of the heat transfer layer is equal to or larger than a thickness of the exterior barrier layer.
A packaging according to a sixteenth aspect of the present invention includes: an exterior film for sealing the electrode assembly; and a heat transfer material attached to the outer packaging so as to expose at least a part of a surface of the outer packaging, in which the exterior film includes at least a base material layer, an exterior barrier layer, and a heat-sealable resin layer, the exterior barrier layer is formed of a material containing a metal, and the heat transfer material includes a heat transfer layer formed of a material containing a metal.
An electrical storage device, a heat transfer material and a packaging according to the present invention enable more suitably suppressing an excessive rise in temperature of an electrode assembly.
Hereinafter, an electrical storage device according to an embodiment of the present invention will be described with reference to the drawings. In the present specification, a numerical range indicated by the term “A to B” means “A or more” and “B or less”. For example, the expression of “2 to 15 mm” means 2 mm or more and 15 mm or less.
The electrode assembly 20 includes electrodes (a positive electrode and a negative electrode), a separator and the like which constitute an electrical storage member such as a lithium ion battery, a capacitor or an all-solid-state battery. The electrode assembly 20 has a substantially rectangular parallelepiped shape. The term “substantially rectangular parallelepiped” means not only a perfect rectangular parallelepiped, but also a three-dimensional shape which can be regarded as a rectangular parallelepiped if the shape of a part of an outer surface is modified.
The electrode terminal 50 is a metal terminal used for input/output of electric power in the electrode assembly 20. One end part of the electrode terminal 50 is electrically connected to an electrode (positive electrode or negative electrode) in the electrode assembly 20, and the other end part protrudes outward from an end edge of the outer packaging 30.
The metal material forming the electrode terminal 50 is, for example, aluminum, nickel or copper. For example, when the electrode assembly 20 is a lithium ion battery, the electrode terminal 50 connected to the positive electrode is typically formed of aluminum or the like, and the electrode terminal 50 connected to the negative electrode is typically formed of copper, nickel or the like.
The outer packaging 30 includes an exterior film 40 (
The base material layer 41 is a layer for imparting heat resistance to the exterior film 40 and suppressing generation of pinholes which may occur during processing or distribution. The base material layer 41 includes, for example, at least one of an oriented polyester resin layer and an oriented polyamide resin layer. For example, when the base material layer 41 includes at least one of an oriented polyester resin layer and an oriented polyamide resin layer, breakage of the exterior film 40 can be suppressed by protecting the exterior barrier layer 42 during processing of the exterior film 40. From the viewpoint of increasing the tensile elongation of the exterior film 40, the oriented polyester resin layer is preferably a biaxially oriented polyester resin layer, and the oriented polyamide resin layer is preferably a biaxially oriented polyamide resin layer. Further, from the viewpoint of excellent piercing strength or shock strength, the oriented polyester resin layer is more preferably a biaxially oriented polyethylene terephthalate (PET) film, and the oriented polyamide resin layer is more preferably a biaxially oriented nylon (ONy) film. The base material layer 41 may include both an oriented polyester resin layer and an oriented polyamide resin layer. From the viewpoint of film strength, the thickness of the base material layer 41 is, for example, preferably 5 to 300 μm, more preferably 20 to 150 μm.
The exterior barrier layer 42 is formed of a material containing a metal. Examples of the metal include aluminum alloys, stainless steel, titanium steel, and steel plates. In the present embodiment, it is preferable that the exterior barrier layer 42 is formed of a material containing an aluminum alloy or stainless steel. The aluminum alloy is excellent in moisture barrier property, processability such as extensibility and economic efficiency. It is preferable that the material forming the exterior barrier layer 42 contains iron from the viewpoint of packaging suitability and pinhole resistance in packaging of the electrode assembly 20. The content of iron in the material forming the exterior barrier layer 42 is preferably 0.5 to 5.0 mass %, more preferably 0.7 to 2.0 mass %. When the content of iron is 0.5 mass % or more, the exterior film 40 has packaging suitability, excellent pinhole resistance, and extensibility of exterior film 40. When the content of iron is 5.0 mass % or less, the exterior film 40 has excellent flexibility.
From the viewpoint of the barrier property, pinhole resistance and packaging suitability, the thickness of the exterior barrier layer 42 is preferably 15 μm or more, more preferably 30 μm or more. The thickness of the exterior barrier layer 42 is preferably 100 μm or less, more preferably 90 μm or less, more preferably 85 μm or less, still more preferably 80 μm or less. The thickness of the exterior barrier layer 42 is preferably in the range of, for example, 15 μm to 100 μm, 15 μm to 90 μm, 15 μm to 85 μm, 15 μm to 80 μm, 30 μm to 100 μm, 30 μm to 90 μm, 30 μm to 85 μm, or 30 μm to 80 μm. When the thickness of the exterior barrier layer 42 is 15 μm or more, the exterior film 40 is unlikely to be broken even if stress is applied by packaging processing. When the thickness of the exterior barrier layer 42 is 100 μm or less, an increase in mass of the exterior film 40 can be reduced, so that it is possible to suppress a decrease in weight energy density of the electrical storage device 10.
Since the exterior barrier layer 42 is formed of a material containing a metal, it is preferable that the exterior film 40 includes a corrosion-resistant film on at least a surface on a side opposite to the base material layer 41 for preventing dissolution and corrosion. The exterior barrier layer 42 may include a corrosion-resistant film on each of both surfaces thereof. Here, the corrosion-resistant film refers to a thin film obtained by subjecting the surface of the exterior barrier layer 42 to, for example, hydrothermal denaturation treatment such as boehmite treatment, chemical conversion treatment, anodization treatment, plating treatment with nickel, chromium or the like, or corrosion prevention treatment by application of a coating agent to impart corrosion resistance (e.g. acid resistance and alkali resistance) to the exterior barrier layer 42. Specifically, the corrosion-resistant film means a film which improves the acid resistance of the exterior barrier layer 42 (acid-resistant film), a film which improves the alkali resistance of the exterior barrier layer 42 (alkali-resistant film), or the like. One of treatments for forming the corrosion-resistant film may be performed, or two or more thereof may be performed in combination. In addition, not only one layer but also multiple layers can be formed. Further, of these treatments, the hydrothermal denaturation treatment and the anodization treatment are treatments in which the surface of the metal foil is dissolved with a treatment agent to form a metal compound excellent in corrosion resistance. The definition of the chemical conversion treatment may include these treatments. When the exterior barrier layer 42 is provided with the corrosion-resistant film, the exterior barrier layer 42 is regarded as including the corrosion-resistant film.
The corrosion-resistant film exhibits the effects of preventing delamination between the exterior barrier layer 42 and the base material layer 41 during molding of the exterior film 40; preventing dissolution and corrosion of the surface of the exterior barrier layer 42, and dissolution and corrosion of aluminum oxide present on the surface of the exterior barrier layer 42 by hydrogen fluoride generated by reaction of an electrolyte with moisture; and improving the bondability (wettability) of the surface of the exterior barrier layer 42 to prevent delamination between the base material layer 41 and the exterior barrier layer 42 during heat-sealing and delamination between the base material layer 41 and the exterior barrier layer 42 during molding.
The heat-sealable resin layer 43 is a layer that imparts a sealing property in heat-sealing to the exterior film 40. Examples of the heat-sealable resin layer 43 include resin films formed of a polyolefin-based resin, or an acid-modified polyolefin-based resin obtained by graft-modification of a polyolefin-based resin with an acid such as maleic anhydride. The heat-sealable resin layer 43 may be polybutylene terephthalate. From the viewpoint of the sealing property and strength, the thickness of the heat-sealable resin layer 43 is, for example, preferably 20 to 300 μm, more preferably 40 to 150 μm.
The first surface 31 is a surface located on the upper side with the electrical storage device 10 placed on the cooling mechanism 100. A pair of second surfaces 32A and 32B face each other with the electrode assembly 20 interposed therebetween. Each of a pair of second surfaces 32A and 32B is larger in area than the first surface 31. The third surface 33 is a surface located on the lower side with the electrical storage device 10 placed on the cooling mechanism 100, in other words, a surface which is cooled by the cooling mechanism 100. Hereinafter, the third surface 33 is sometimes referred to as a cooling surface 33. In the present embodiment, the area of the cooling surface 33 is equal to the area of the first surface 31. A pair of fourth surfaces 34A and 34B are surfaces through which the electrode terminal 50 extends. A pair of fourth surfaces 34A and 34B face each other with the electrode assembly 20 interposed therebetween. In the present embodiment, a pair of fourth surfaces 34A and 34B are smaller in area than the first surface 31 and the cooling surface 33.
As the material constituting base material layer 60A, the same material as exemplified for the base material layer 41 of the exterior film 40 may be used. In the present embodiment, the material for forming the base material layer 60A is polyethylene terephthalate.
Preferably, the innermost layer 60C is formed of a material capable of being heat-sealed to the base material layer 41 of exterior film 40, in other words, the innermost layer 60C is a heat-sealable resin layer. When the innermost layer 60C is a heat-sealable resin layer, the same material as exemplified for the heat-scalable resin layer 43 of the exterior film 40 may be used as the material for forming the innermost layer 60C. In the present embodiment, the material for forming the innermost layer 60C is polypropylene. The material for forming the innermost layer 60C may be, for example, an olefin-based resin other than polypropylene, or polybutylene terephthalate. When the innermost layer 60C is not a heat-sealable resin layer, the material for forming the innermost layer 60C may be, for example, an adhesive such as a urethane resin or a pressure sensitive adhesive, or the innermost layer 60C may be formed of any material capable of being joined to the base material layer 41 of the exterior film 40 with a double-sided tape or the like interposed therebetween. An example of the adhesive is a urethane resin.
Similarly to the exterior barrier layer 42, the heat transfer layer 60B may be formed of a material containing a metal, and examples of the metal include aluminum alloys, copper, gold, silver, brass, iron, and stainless steel from the viewpoint of heat conductivity. In the present embodiment, it is preferable that the heat transfer layer 60B is formed of a material containing an aluminum alloy or copper from the viewpoint of heat conductivity and cost. The material for forming the heat transfer layer 60B and the preferred configuration are the same as in the case of the exterior barrier layer 42, and the thickness of the heat transfer layer 60B is preferably equal to or larger than the thickness of the exterior barrier layer 42 for suitably transferring heat generated from the electrode assembly 20 to the cooling mechanism 100. The thickness of the heat transfer layer 60B is preferably 15 μm or more, more preferably 30 μm or more. From the viewpoint of moldability and productivity of the heat transfer material 60, the thickness of the heat transfer layer 60B is preferably 100 μm or less, more preferably 90 μm or less, more preferably 85 μm or less, still more preferably 80 μm or less. The thickness of the heat transfer layer 60B is preferably in the range of, for example, 15 μm to 100 μm, 15 μm to 90 μm, 15 μm to 85 μm, 15 μm to 80 μm, 30 μm to 100 μm, 30 μm to 90 μm, 30 μm to 85 μm, or 30 μm to 80 μm. When the thickness of the heat transfer layer 60B is 15 μm or more, heat generated from the electrode assembly 20 can be suitably transferred to the cooling mechanism 100. When the thickness of the heat transfer layer 60B is 100 μm or less, the moldability and productivity of the heat transfer material 60 are improved. From the viewpoint of suitably transferring heat generated in the electrode assembly 20 to the cooling mechanism 100, the thickness of the heat transfer layer 60B is preferably as thick as possible. Therefore, when the sheet-shaped heat transfer material 60 is not molded, in other words, processing such as bending is not performed, the thickness of the heat transfer layer 60B is preferably 300 μm or less.
When the electrode assembly 20 generates heat, a part of the heat is transferred to the first surface 31 to the fourth surfaces 34A and 34B of the outer packaging 30. For suitably transferring the heat of the electrode assembly 20 to the cooling mechanism 100, it is preferable that the heat transfer material 60 is attached to at least a pair of second surfaces 32A and 32B of the outer packaging 30 which have a large area. On the other hand, when the electrical storage device 10 is at work, it is preferable that heat transferred to the cooling surface 33 is rapidly transferred to the cooling mechanism 100 because the cooling surface 33 is in contact with the cooling mechanism 100 (see
The shape of the heat transfer material 60 can be arbitrarily selected as long as it is a shape which allows the heat transfer material 60 to be attached to a surface of the outer packaging 30. In the present embodiment, the heat transfer material 60 is formed in a cover shape so that the heat transfer material 60 can be easily attached to the outer packaging 30. The heat transfer material 60 is not required to be molded in a cover shape, and may have just a sheet shape. The heat transfer material 60 includes a first portion 61 and a pair of second portions 62A and 62B, and has a shape similar to a U shape. The first portion 61 is attached to the first surface 31 of the outer packaging 30. The shape of the first portion 61 is the same as the shape of the first surface 31. A pair of second portions 62A and 62B are connected to the first portion 61. A pair of second portions 62A and 62B are attached to a pair of second surfaces 32A and 32B of the outer packaging 30. The second portion 62A is attached to the second surface 30A of the outer packaging 32. The shape of the second portion 62A is the same as the shape of the second surface 32A. The second portion 62B is attached to the second surface 30B of the outer packaging 32. The shape of the second portion 62B is the same as the shape of the second surface 32B.
In the electrical storage device according to the present embodiment, the exterior film 40 including the exterior barrier layer 42 and the heat transfer material 60 including the heat transfer layer 60B are formed as separate members, so that an increase in thickness of each of the exterior film 40 and the heat transfer material 60 is suppressed. Therefore, the exterior film 40 and the heat transfer material 60 can be favorably manufactured. If the electrode assembly 20 generates heat, the heat is transferred to the cooling mechanism 100 through a first heat transfer route, a second heat transfer route, a third heat transfer route and a fourth heat transfer route.
The first heat transfer route is a route in which on the third surface 33 of the outer packaging 30, heat is transferred in order along the lamination direction of the exterior film 40, that is, heat is transferred to the heat-sealable resin layer 43, the exterior barrier layer 42 and the base material layer 41 of the exterior film 40 and the cooling mechanism 100 in the stated order. Therefore, when the first heat transfer route is taken into consideration, the thickness of exterior film 40 is preferably thin.
The second heat transfer route is a route in which heat is transferred to the heat-sealable resin layer 43 and the exterior barrier layer 42 of the exterior film 40, and then transferred from the exterior barrier layer 42 to the cooling mechanism 100 and from the base material layer 41 to the cooling mechanism 100. If the heat conduction rate is low in the second heat transfer route, a part of the heat is transferred to the heat transfer material 60, and shifts to the fourth heat transfer route. Since the heat transfer material 60 has a function of assisting heat transfer through the second heat transfer route, heat conduction in a plane direction that is a direction perpendicular to the lamination direction is important. Therefore, the thickness of the heat transfer layer 60B of the heat transfer material 60 is preferably as thick as possible.
The third heat transfer route is a route in which heat is transferred to the heat-sealable resin layer 43, the exterior barrier layer 42 and the base material layer 41 of the exterior film 40, the innermost layer 60C and the heat transfer layer 60B of the heat transfer material 60 and the cooling mechanism 100 in the stated order.
The fourth heat transfer route is a route in which heat is transferred to the heat-sealable resin layer 43, the exterior barrier layer 42 and the base material layer 41 of the exterior film 40, the innermost layer 60C, the heat transfer layer 60B and the innermost layer 60C of the heat transfer material 60, the base material layer 41, the exterior barrier layer 42, the base material layer 41 and the cooling mechanism 100 in the stated order.
Since the electrical storage device 10 includes the heat transfer material 60, so that the heat transfer through the third heat transfer route and the fourth heat transfer route proceeds in addition to the first heat transfer route and the second heat transfer route, an excessive rise in temperature of the electrical storage device 10 can be suitably suppressed. The electrical storage device 10 further exhibits the following effects.
<6-1>
Since the thickness of the heat transfer layer 60B is equal to or larger than the thickness of the exterior barrier layer 42, heat is suitably transferred to the cooling mechanism 100 through the heat transfer material 60 in the third heat transfer route and the fourth heat transfer route.
<6-2>
The heat transfer material 60 is attached to at least the second surfaces 32A and 32B of the outer packaging 30 which have a relatively large area. Therefore, heat generated from the electrode assembly 20 can be more suitably transferred to the cooling mechanism 100.
<6-3>
Since the heat transfer material 60 is formed in a cover shape, the heat transfer material 60 can be easily attached to the outer packaging 30.
<6-4>
Since the heat transfer material 60 is not attached to the cooling surface 33, heat transferred to the cooling surface 33 can be rapidly transferred to the cooling mechanism 100.
<6-5>
Since the thickness of the exterior barrier layer 42 is 100 μm or less, the moldability and productivity of the heat transfer material 60 are improved.
The inventors of the present application conducted a test in which a relationship between a temperature when a heat transfer material was not attached and a temperature when a heat transfer material was attached was confirmed by simulation for the electrical storage device of each of Examples. In the following description, among the elements forming the electrical storage devices of Examples, elements that are identical to those in the embodiment are given the same symbols as in the embodiment.
In Examples 1 to 5, it was confirmed that a rise in temperature of the electrical storage device 10 was suppressed in the case where the heat transfer material 60 is attached to the outer packaging 30 as compared to the case where the heat transfer material 60 is not attached as shown in
The embodiment is an example of possible forms of the electrical storage device, the heat transfer material and the packaging according to the present invention, and is not intended to limit the forms thereof. The electrical storage device, the heat transfer material and the packaging according to the present invention may have a form different from that exemplified in the embodiment. An example thereof is a form in which a part of the configuration of the embodiment is replaced, changed or omitted, or a form in which a new configuration is added to the embodiment. Some examples of modifications of the embodiment will be described below.
<8-1>
A location on the outer packaging 30 at which the heat transfer material 60 is attached can be arbitrarily selected. For example, the heat transfer material 60 may be attached to at least one of a pair of fourth surfaces 30A and 34B of the outer packaging 34.
<8-2>
In the embodiment, the first portion 61 and each of the second portions 62A and 62B of the heat transfer material 60 are connected to each other, but the first portion 61 and at least one of a pair of second portions 62A and 62B may be separated from each other.
<8-3>
In the embodiment, the heat transfer material 60 and the outer packaging 30 are joined, but when the heat transfer material 60 is formed in a cover shape, the beat transfer material 60 and the outer packaging 30 are not required to be joined. When the heat transfer material 60 has a sheet shape, in other words, the heat transfer material 60 is not molded, the heat transfer material 60 may be placed on the first surface 31 of the outer packaging 30, for example. In short, the heat transfer material 60 is only required cover at least a part of a surface of the outer packaging 30.
<8-4>
In the embodiment, the metal in the material forming the exterior barrier layer 42 and the metal in the material forming the heat transfer layer 60B are aluminum. However, the metal in the material forming the exterior barrier layer 42 and the metal in the material forming the heat transfer layer 60B may be different from each other.
<8-5>
In the embodiment, the heat transfer material 60 may include one or more layers having a buffer function outside the heat transfer layer 60B. The buffer layer may be laminated on the outer side of the base material layer 60A, and the base material layer 60A may also have a function of the buffer layer. When the heat transfer material 60 include a plurality of buffer layers, the buffer layers may be adjacent to each other, or may be laminated with the base material layer 60A, the heat transfer layer 60B or the like interposed therebetween.
The material for forming the buffer layer can be arbitrarily selected from materials having a cushioning property. The material having a cushioning property is, for example, rubber, a nonwoven fabric, or a foamed sheet. The rubber is, for example, natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably about 20 to 90. The material forming the nonwoven fabric is preferably a material having excellent heat resistance. When the buffer layer is formed of a nonwoven fabric, the lower limit of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, still more preferably 1000 μm. When the buffer layer is formed of a nonwoven fabric, the upper limit of the thickness of the buffer layer is preferably 5,000 μm, more preferably 3,000 μm. A preferable range of the thickness of the buffer layer is 100 μm to 5,000 μm, 100 μm to 3,000 μm, 200 μm to 3,000 μm, 1,000 μm to 5,000 μm, or 1,000 μm to 3,000 μm. In particular, the thickness of the buffer layer is most preferably in the range of 1,000 μm to 3,000 μm.
When the buffer layer is formed of rubber, the lower limit of the thickness of the buffer layer is preferably 0.5 mm. When the buffer layer is formed of rubber, the upper limit of the thickness of the buffer layer is preferably 10 mm, more preferably 5 mm, still more preferably 2 mm. When the buffer layer is formed of rubber, the thickness of the buffer layer is preferably in the range of 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.
When the heat transfer material 60 has a buffer layer, the buffer layer functions as a cushion, so that the heat transfer material 60 is inhibited from being damaged by an impact in case where the electrical storage device 10 falls, or handling during manufacturing of the electrical storage device 10. When application of pressure to a battery is required as in the case of an all-solid-state battery, the pressure can be uniformly applied to the battery.
<8-6>
In the embodiment, the cooling mechanism 100 is a water-cooling type cooling mechanism, but the configuration of the cooling mechanism 100 is not limited thereto. For example, the cooling mechanism 100 may be an air-cooling type cooling mechanism. In this modification, the cooling surface 33 is in contact with air.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-108193 | Jun 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/025753 | 6/28/2022 | WO |
