WO2022071425A1

WO2022071425A1 - Battery cover

Info

Publication number: WO2022071425A1
Application number: PCT/JP2021/035946
Authority: WO
Inventors: 誠甲斐; 拓道齋藤
Original assignee: 日東電工株式会社
Priority date: 2020-09-30
Filing date: 2021-09-29
Publication date: 2022-04-07
Also published as: JP2022057619A

Abstract

A battery cover 1 comprises a thermal insulation layer 13 and a heat transfer layer 14. The thermal insulation layer 13 comprises a first portion 13A and a second portion 13B separated from the first portion 13A. The heat transfer layer 14 transmits heat between the first portion 13A and the second portion 13B. The thermal conductivity of the heat transfer layer 14 is 0.5 W/(m•K) or greater and is higher than the thermal conductivity of the thermal insulation layer 13.

Description

Battery cover

The present invention relates to a battery cover.

Conventionally, as a battery cover attached to a battery, a side wall covering the side surface of the battery is provided, and the side wall includes a porous layer having heat insulating properties and a protective layer arranged on one side and the other side in the thickness direction of the porous layer. A battery cover has been proposed (see, for example, Patent Document 1).

International Publication No. 2019/098231

In the battery cover described in Patent Document 1, it is desired to improve the heat insulating property while suppressing the increase in thickness.

For example, when a battery cover is attached to a battery that is housed together with a large number of parts in a limited space such as an automobile engine room, it is desirable to improve heat insulation while avoiding interference with surrounding parts. Is done.

Therefore, an object of the present invention is to provide a battery cover capable of improving heat insulation while suppressing an increase in thickness.

In the present invention [1], heat is transferred between a heat insulating layer having a first portion and a second portion separated from the first portion, and the first portion and the second portion, and the thermal conductivity is increased. It includes a battery cover having a heat transfer layer higher than that of the heat insulating layer and having a thermal conductivity of 0.5 W / (m · K) or more of the heat transfer layer.

According to such a configuration, for example, when the first portion is heated by the heat source while the battery cover is attached to the battery, the heat of the first portion is separated from the first portion by the heat transfer layer. It can be efficiently communicated to the second part.

Thereby, even if the thickness of the battery cover is not increased, the heat from the heat source can be suppressed from being transferred to the battery by transferring the heat of the first part to the second part.

As a result, it is possible to improve the heat insulating property while suppressing the increase in the thickness of the battery cover.

The present invention [2] includes the battery cover of the above [1] in which the heat transfer layer is made of metal.

With such a configuration, the heat insulating property of the battery cover can be further improved.

The present invention [3] includes the battery cover of the above [1] or [2] in which the thickness of the heat insulating layer is 1 mm or more.

With such a configuration, the heat insulating property of the battery cover can be ensured.

The present invention [4] includes a battery cover according to any one of the above [1] to [3], which is removable from the battery.

The present invention [5] includes the battery cover of the above [4], which is a side wall covering the side surface of the battery and includes a side wall having the heat insulating layer and the heat transfer layer.

The present invention [6] provides a sealing member in which the side wall faces the side surface of the battery at a distance, and the battery cover seals between the edge of the side wall and the side surface of the battery. Further, the battery cover of the above [5] is included.

According to such a configuration, the air heated by the heat source can be suppressed from entering between the battery cover and the battery by the sealing member.

This makes it possible to further improve the heat insulating properties of the battery cover.

The present invention [7] includes the battery cover of the above [5] or [6] in which the heat transfer layer is arranged between the side surface of the battery and the heat insulating layer.

The present invention [8] includes a battery cover according to any one of [4] to [7], wherein the first portion is arranged between a heat source arranged away from the battery and the battery. ..

According to such a configuration, with the battery cover attached to the battery, the heat of the first portion heated by the heat source can be transferred to the second portion away from the first portion by the heat transfer layer. ..

The present invention [9] includes the battery cover of the above [8] in which the distance between the second portion and the heat source is longer than the distance between the first portion and the heat source.

According to such a configuration, the heat of the first part can be transferred to the second part away from the heat source.

The present invention [10] includes any one of the battery covers [4] to [9], wherein the second portion is arranged on the opposite side of the first portion with respect to the battery.

According to such a configuration, the heat of the first part can be transferred to the opposite side of the first part to the battery.

According to the battery cover of the present invention, it is possible to improve the heat insulating property while suppressing the increase in thickness.

FIG. 1 is a perspective view of a battery to which a battery cover as an embodiment of the present invention is attached. FIG. 2 is a perspective view of the battery shown in FIG. FIG. 3 is a perspective view of the battery cover shown in FIG. FIG. 4 is an explanatory diagram for explaining the positional relationship between the battery cover and the heat source. FIG. 5 shows a first modification of the battery cover. FIG. 6 shows a second modification of the battery cover. FIG. 7 shows a third modification of the battery cover. FIG. 8 shows a fourth modification of the battery cover. FIG. 9 shows a fifth modification of the battery cover. FIG. 10 shows a sixth modification of the battery cover. FIG. 11 shows a seventh modification of the battery cover. FIG. 12 shows an eighth modification of the battery cover. FIG. 13 shows a ninth modification of the battery cover. FIG. 14 shows a tenth modification of the battery cover. FIG. 15 shows an eleventh modification of the battery cover. FIG. 16A is an explanatory diagram for explaining the configuration of the heat insulating property evaluation device. FIG. 16B is an explanatory diagram illustrating points for measuring the temperature of the heat insulating layer and the temperature of the resin plate in the evaluation device of FIG. 16A. FIG. 17A is an explanatory diagram for explaining a method for evaluating the heat insulating properties of Examples and Comparative Examples shown in Table 2. FIG. 17B is an explanatory diagram for explaining a method for evaluating the heat insulating properties of Examples and Comparative Examples shown in Table 3.

As shown in FIG. 1, the battery cover 1 as an embodiment of the present invention is attached to the battery 100. The battery cover 1 attached to the battery 100 is removable from the battery 100. That is, the battery cover 1 is removable from the battery 100.

1. 1. Battery The battery 100 will be described with reference to FIG.

In this embodiment, the battery 100 is a lead storage battery. The battery 100 is not limited to a lead storage battery, and may be a secondary battery such as a lithium ion secondary battery.

The battery 100 has a substantially rectangular parallelepiped shape. The battery 100 includes a battery case 101, a lid 102, a positive electrode plate (not shown), a negative electrode plate (not shown), a positive electrode terminal 103 as an example of a terminal, and a negative electrode terminal 104 as an example of a terminal. To prepare for.

The battery case 101 has an opening (not shown). The opening is arranged at one end of the battery case 101 in the first direction. The battery case 101 houses a positive electrode plate, a negative electrode plate, and an electrolyte. When the battery 100 is a secondary battery such as a lithium ion secondary battery, the battery case 101 may accommodate a plurality of cells.

The lid 102 is attached to one end of the battery case 101 in the first direction. The lid 102 closes the opening of the battery case 101.

The positive electrode terminal 103 and the negative electrode terminal 104 are attached to the lid 102. The positive electrode terminal 103 is electrically connected to the positive electrode plate. The negative electrode terminal 104 is electrically connected to the negative electrode plate. The negative electrode terminal 104 is arranged at a distance from the positive electrode terminal 103 in the second direction. The second direction is orthogonal to the first direction.

The battery 100 has a first surface S1, a second surface S2, and a side surface S3. In the present embodiment, the first surface S1 is the upper outer surface of the lid 102. The positive electrode terminal 103 and the negative electrode terminal 104 are arranged on the first surface S1. The second surface S2 is the lower outer surface of the battery case 101. The second surface S2 is separated from the first surface S1 in the first direction. The side surface S3 is a side surface of the battery case 101. The side surface S3 is arranged between the first surface S1 and the second surface S2 in the first direction. The side surface S3 extends in the first direction. In the present embodiment, the side surface S3 includes a first side surface S31, a second side surface S32, a third side surface S33, and a fourth side surface S34.

The first side surface S31 is the outer surface of one side of the battery case 101 in the third direction. The third direction is orthogonal to the first and second directions. The first side surface S31 extends in the first direction and the second direction.

The second side surface S32 is the outer surface of the other side of the battery case 101 in the third direction. The second side surface S32 extends in the first direction and the second direction.

The third side surface S33 is the outer surface of one side of the battery case 101 in the second direction. The third side surface S33 extends in the first direction and the third direction. One end of the third side surface S33 in the third direction is connected to one end of the first side surface S31 in the second direction. The other end of the third side surface S33 in the third direction is connected to one end of the second side surface S32 in the second direction.

The fourth side surface S34 is the outer surface of the other side of the battery case 101 in the second direction. The fourth side surface S34 extends in the first direction and the third direction. One end of the fourth side surface S34 in the third direction is connected to the other end of the first side surface S31 in the second direction. The other end of the fourth side surface S34 in the third direction is connected to the other end of the second side surface S32 in the second direction.

2. 2. Battery cover Next, the battery cover 1 will be described with reference to FIGS. 1 to 4.

As shown in FIG. 1, with the battery cover 1 attached to the battery 100, the battery cover 1 covers the outer surface of the battery 100. With the battery cover 1 attached to the battery 100, the battery cover 1 suppresses the transfer of ambient heat to the battery 100.

The battery cover 1 may expose a part of the outer surface of the battery 100. In the present embodiment, with the battery cover 1 attached to the battery 100, the battery cover 1 covers the side surface S3 of the battery 100 and exposes the first surface S1 and the second surface S2 (see FIG. 2) of the battery 100. do. With the battery cover 1 attached to the battery 100, the battery cover 1 surrounds the battery 100.

(1) Shape of battery cover As shown in FIG. 3, the battery cover 1 has a tubular shape. The battery cover 1 extends in the first direction. The battery cover 1 includes a side wall 2. In the present embodiment, the battery cover 1 includes only the side wall 2. With the battery cover 1 attached to the battery 100 (see FIG. 1), the side wall 2 covers the side surface S3 of the battery 100. In the present embodiment, the side wall 2 includes a first side wall 2A, a second side wall 2B, a third side wall 2C, and a fourth side wall 2D.

The first side wall 2A is arranged at one end of the battery cover 1 in the third direction. The first side wall 2A extends in the first direction and the second direction. The first side wall 2A has a flat plate shape. With the battery cover 1 attached to the battery 100, the first side wall 2A covers the first side surface S31 (see FIG. 2) of the battery 100.

The second side wall 2B is arranged at the other end of the battery cover 1 in the third direction. The second side wall 2B is arranged at a distance from the first side wall 2A in the third direction. With the battery cover 1 attached to the battery 100, the second side wall 2B is arranged on the opposite side of the first side wall 2A with respect to the battery 100 in the third direction. The second side wall 2B extends in the first direction and the second direction. The second side wall 2B has a flat plate shape. With the battery cover 1 attached to the battery 100, the second side wall 2B covers the second side surface S32 (see FIG. 2) of the battery 100.

The third side wall 2C is arranged at one end of the battery cover 1 in the second direction. The third side wall 2C extends in the first direction and the third direction. The third side wall 2C has a flat plate shape. With the battery cover 1 attached to the battery 100, the third side wall 2C covers the third side surface S33 (see FIG. 2) of the battery 100. One end of the third side wall 2C in the third direction is connected to one end of the first side wall 2A in the second direction. The other end of the third side wall 2C in the third direction is connected to one end of the second side wall 2B in the second direction.

The fourth side wall 2D is arranged at the other end of the battery cover 1 in the second direction. The fourth side wall 2D is arranged at a distance from the third side wall 2C in the second direction. With the battery cover 1 attached to the battery 100, the fourth side wall 2D is arranged in the second direction on the opposite side of the third side wall 2C with respect to the battery 100. The fourth side wall 2D extends in the first direction and the third direction. The fourth side wall 2D has a flat plate shape. With the battery cover 1 attached to the battery 100, the fourth side wall 2D covers the fourth side surface S34 (see FIG. 2) of the battery 100. One end of the fourth side wall 2D in the third direction is connected to the other end of the first side wall 2A in the second direction. The other end of the fourth side wall 2D in the third direction is connected to the other end of the second side wall 2B in the second direction.

Further, as shown in FIG. 4, the side wall 2 has an inner surface S11, an outer surface S12, and edges 3A and 3B.

With the battery cover 1 attached to the battery 100, the inner surface S11 faces the side surface S3 of the battery 100 at a distance in the thickness direction of the side wall 2. In other words, with the battery cover 1 attached to the battery 100, the side wall 2 faces the side surface S3 of the battery 100 at a distance. In the present embodiment, in the first side wall 2A and the second side wall 2B, the "thickness direction" is the third direction. Further, in the third side wall 2C (see FIG. 1) and the fourth side wall 2D (see FIG. 1), the "thickness direction" is the second direction.

With the battery cover 1 attached to the battery 100, the outer surface S12 is arranged on the opposite side of the side surface S3 (see FIG. 2) of the battery 100 with respect to the inner surface S11 in the thickness direction.

The edge 3A is arranged at one end (upper end) of the battery cover 1 in the first direction. The edge 3A extends over the entire circumference of the battery cover 1.

The edge 3B is arranged at a distance from the edge 3A in the first direction. The edge 3B is arranged at the other end (lower end) of the battery cover 1 in the first direction. The edge 3B extends over the entire circumference of the battery cover 1 in the same manner as the edge 3A.

(2) Layer structure of the battery cover The battery cover 1 includes a first surface layer 11, a second surface layer 12, a heat insulating layer 13, a heat transfer layer 14, and sealing

members

15A and 15B. In the present embodiment, the side wall 2 has a first surface layer 11, a second surface layer 12, a heat insulating layer 13, and a heat transfer layer 14.

(2-1) First surface layer The first surface layer 11 is the innermost layer of the side wall 2 in the thickness direction. With the battery cover 1 attached to the battery 100, in the thickness direction, the first surface layer 11 is between the side surface S3 of the battery 100 and the heat insulating layer 13, or between the side surface S3 of the battery 100 and the heat transfer layer 14. Placed in between. The first surface layer 11 protects the heat insulating layer 13 and the heat transfer layer 14 inside in the thickness direction. The first surface layer 11 is arranged on the entire side wall 2. With the battery cover 1 attached to the battery 100, the first surface layer 11 faces the side surface S3 of the battery 100 at a distance. The first surface layer 11 has an inner surface S11.

Examples of the material of the first surface layer 11 include non-woven fabric, woven fabric, plastic sheet and plastic film.

Examples of materials for non-woven fabrics and woven fabrics include natural fibers and chemical fibers. Natural fibers include, for example, cotton, hemp, pulp, wool, silk and mineral fibers. Examples of the chemical fiber include polyester fiber, polyethylene fiber, polypropylene fiber, nylon fiber, aramid fiber, acrylic fiber, vinylon fiber, rayon and glass fiber. The non-woven fabric and the woven fabric may consist of a single type of fiber or may consist of a plurality of types of fibers.

Examples of the material of the plastic sheet and the plastic film include thermosetting resin and thermoplastic resin. Examples of the thermosetting resin include polyester resin, polyurethane resin and polycarbonate resin. Examples of the thermoplastic resin include polyolefin resins, polyvinyl chloride and styrene-butadiene rubber. The plastic sheet and the plastic film may be made of a single kind of resin or may be made of a plurality of kinds of resins.

The first surface layer 11 is preferably made of a non-woven fabric. When the first surface layer 11 is made of a non-woven fabric, the material of the non-woven fabric is preferably chemical fiber, more preferably polyester fiber and polypropylene fiber, and even more preferably polyethylene terephthalate (PET) fiber and. Polypropylene fiber can be mentioned.

When the first surface layer 11 contains polyethylene terephthalate fiber, the heat resistance of the first surface layer 11 can be improved. When the first surface layer 11 contains polypropylene fibers, the first surface layer 11 can be easily heat-welded to the second surface layer 12. When the first surface layer 11 contains polyethylene terephthalate fibers and polypropylene fibers, both the heat resistance of the first surface layer 11 and the heat welding property of the first surface layer 11 to the heat insulating layer 13 or the second surface layer 12 can be achieved at the same time.

The method for manufacturing the non-woven fabric is not limited. Examples of the method for producing a nonwoven fabric include a fleece forming method and a fleece bonding method. Examples of the fleece forming method include a dry method, a wet method, a spunbond method and a melt blow method. Examples of the fleece bonding method include a thermal bond method, a chemical bond method, a stitch bond method, a needle punch method, a spunlace method and a steam jet method.

The non-woven fabric may be impregnated with resin. The resin impregnated in the non-woven fabric is not limited. Examples of the resin impregnated in the non-woven fabric include thermosetting resin and thermoplastic resin. Examples of the thermosetting resin include phenol resin and resilcinol resin. Examples of the thermoplastic resin include vinyl acetate-based resins and olefin-based resins. Examples of the vinyl acetate resin include ethylene vinyl acetate (EVA). Examples of the olefin resin include amorphous polyolefin (APAO).

Further, the nonwoven fabric may be a laminate of a resin layer and a fiber layer. Examples of the resin layer include the above-mentioned layer made of vinyl acetate resin. Examples of the fiber layer include the above-mentioned layer made of a non-woven fabric and a woven material. Specifically, vinyl acetate-based resin, polyester fiber (more specifically, polyethylene terephthalate fiber), and polypropylene fiber are vinyl acetate-based resin (resin layer), polyester fiber (fiber layer), polypropylene fiber (fiber layer). ), A non-woven fabric laminated in the order of vinyl acetate resin (resin layer).

The thickness of the first surface layer 11 is thinner than the thickness of the heat insulating layer 13. The thickness of the first surface layer 11 is, for example, 0.01 mm or more, preferably 0.1 mm or more, and for example, 10.0 mm or less, preferably 5.0 mm or less.

(2-2) Second surface layer The second surface layer 12 is the outermost layer of the side wall 2 in the thickness direction. The second surface layer 12 is arranged on the opposite side of the first surface layer 11 with respect to the heat insulating layer 13 in the thickness direction. The second surface layer 12 protects the heat insulating layer 13 on the outside in the thickness direction. With the battery cover 1 attached to the battery 100, the second surface layer 12 is arranged on the opposite side of the side surface S3 of the battery 100 with respect to the first surface layer 11 in the thickness direction. The second surface layer 12 is arranged on the entire side wall 2. The second surface layer 12 has an outer surface S12. At

edges

3A and 3B, the second surface layer 12 is adhered to the first surface layer 11.

As the material of the second surface layer 12, the same material as the material of the first surface layer 11 can be mentioned. The second surface layer 12 may be made of the same material as the first surface layer 11, or may be made of a material different from that of the first surface layer 11.

The thickness of the second surface layer 12 is thinner than the thickness of the heat insulating layer 13. The thickness of the second surface layer 12 is, for example, 0.01 mm or more, preferably 0.1 mm or more, and for example, 10.0 mm or less, preferably 5.0 mm or less. The thickness of the second surface layer 12 may be the same as the thickness of the first surface layer 11 or may be different from the thickness of the first surface layer 11.

(2-3) Insulation layer The insulation layer 13 is arranged between the first surface layer 11 and the second surface layer 12 in the thickness direction. The heat insulating layer 13 is provided on the entire side wall 2. The heat insulating layer 13 is made of a heat insulating material.

Examples of the heat insulating material include foam-based heat insulating materials, fiber-based heat insulating materials, and resin-based heat insulating materials. Examples of the foam-based heat insulating material include urethane foam, phenol foam, polyethylene foam and polystyrene foam. Examples of the fiber-based heat insulating material include glass wool, rock wool, a non-woven fabric containing silica airgel, and cellulose fiber. Examples of the resin-based heat insulating material include plastic corrugated cardboard.

The heat insulating layer 13 is preferably made of a foam-based heat insulating material or a resin-based heat insulating material, more preferably a foam-based heat insulating material, and more preferably urethane foam or phenol foam.

The thermal conductivity of the heat insulating layer 13 is 0.045 W / (m · K) or less, preferably 0.043 W / (m · K) or less, more preferably 0.040 W / (m · K) or less, and further. It is preferably 0.035 W / (m · K) or less, more preferably 0.033 W / (m · K) or less, still more preferably 0.030 W / (m · K) or less, for example, 0. It is 015 W / (m · K) or more. Thermal conductivity is measured by the hot wire method (probe method) in accordance with JIS R 2616: 2001 or ASTM D 5930. Specifically, the thermal conductivity is measured at room temperature using a rapid thermal conductivity meter (manufactured by Kyoto Electronics Industry Co., Ltd., trade name "QTM-500"). The thermal conductivity of the heat insulating layer 13 is a main factor that affects the heat insulating property of the battery cover 1. The heat insulating property of the battery cover 1 can be evaluated by the method described in Examples described later.

Other factors that affect the heat insulating property of the battery cover 1 include, for example, the thermal conductivity of the heat transfer layer 14 described later, the air permeability of the heat insulating layer 13, and the air permeability of the sealing

members

15A and 15B. If the air permeability of the heat insulating layer 13 is excessively high, it becomes difficult for the battery cover 1 to block the high temperature airflow, so that the heat insulating property of the battery cover 1 tends to decrease.

The air permeability can be measured by the B method defined by JIS K 6400-7: 2012 for foams and by the Frazier method defined by JIS L 1913: 2010 for non-woven fabrics.

The air permeability of the heat insulating layer 13 is, for example, 160 ml / cm ² / sec or less, preferably 100 ml / cm ² / sec or less, and more preferably 75 ml / cm ² / sec or less. When the air permeability of the heat insulating layer 13 is not more than the above upper limit value, it is possible to suppress the deterioration of the heat insulating property of the battery cover 1.

The heat insulating layer 13 is harder than the sealing

members

15A and 15B. The 50% compression hardness of the heat insulating layer 13 is higher than the 50% compression hardness of the sealing

members

15A and 15B. The 50% compression hardness is measured according to JIS K 6767: 1999. Specifically, the dimensions (width x length) of the test piece used for measuring the 50% compression hardness are 100 mm x 100 mm. The 50% compression hardness is measured immediately after the test piece is placed between the parallel flat plates of the tester, compressed at a compression rate of 5 mm / min by 50% of the initial thickness and stopped, and the compression is stopped. It is calculated by the following formula based on the applied load P.

Formula: 50% compression hardness = load P ÷ area of test piece (100 mm x 100 mm)
The 50% compression hardness of the heat insulating layer 13 is, for example, 10.0 kPa or more, preferably 11.0 kPa or more, and more preferably 12.0 kPa or more. When the 50% compressive hardness of the heat insulating layer 13 is at least the above lower limit value, it is possible to suppress the deformation of the heat insulating layer 13. The upper limit of the 50% compressive hardness of the heat insulating layer 13 is not limited as long as the heat insulating layer 13 can be formed by hot pressing.

The thickness of the heat insulating layer 13 is, for example, 1 mm or more, preferably 3 mm or more, and more preferably 5 mm or more. When the thickness of the heat insulating layer 13 is at least the above lower limit value, the heat insulating property of the battery cover 1 can be ensured.

The thickness of the heat insulating layer 13 is, for example, 25 mm or less, preferably 20 mm or less. When the thickness of the heat insulating layer 13 is not more than the above upper limit value, it is possible to prevent the battery cover 1 from becoming excessively large.

(2-4) Heat transfer layer The heat transfer layer 14 is arranged between the first surface layer 11 and the heat insulating layer 13 in the thickness direction. With the battery cover 1 attached to the battery 100, the heat transfer layer 14 is arranged between the side surface S3 of the battery 100 and the heat insulating layer 13. The heat transfer layer 14 comes into contact with the heat insulating layer 13.

As shown in FIG. 3, the heat transfer layer 14 extends in a direction orthogonal to the thickness direction. In this embodiment, the heat transfer layer 14 transfers heat between the first side wall 2A and the second side wall 2B through the third side wall 2C and the fourth side wall 2D. Specifically, the heat transfer layer 14 has a first heat transfer layer 14A, a second heat transfer layer 14B, and a third heat transfer layer 14C.

The first heat transfer layer 14A is arranged on the first side wall 2A. The first heat transfer layer 14A extends in the second direction.

The second heat transfer layer 14B is arranged on the third side wall 2C. The second heat transfer layer 14B is connected to one end of the first heat transfer layer 14A in the second direction. The second heat transfer layer 14B extends in the third direction. The second heat transfer layer 14B extends closer to the second side wall 2B than the center of the third side wall 2C in the third direction. The second heat transfer layer 14B may extend to the second side wall 2B.

The third heat transfer layer 14C is arranged on the fourth side wall 2D. The third heat transfer layer 14C is connected to the other end of the first heat transfer layer 14A in the second direction. The third heat transfer layer 14C extends in the third direction. The third heat transfer layer 14C extends closer to the second side wall 2B than the center of the fourth side wall 2D in the third direction. The third heat transfer layer 14C may extend to the second side wall 2B.

The thermal conductivity of the heat transfer layer 14 is higher than that of the heat insulating layer 13. The thermal conductivity of the heat transfer layer 14 is, for example, 0.5 W / (m · K) or more, preferably 1.0 W / (m · K) or more, more preferably 3.0 W / (m · K) or more. That is all. The upper limit of the thermal conductivity of the heat transfer layer 14 is not limited. The thermal conductivity of the heat transfer layer 14 is, for example, 3000 W / (m · K) or less.

The heat transfer layer 14 is made of, for example, a metal, a carbon material, a foam, or a heat conductive tape. Examples of the metal include aluminum, copper, tin and steel. Examples of the carbon material include graphite. Examples of the foam include acrylic foam. The heat transfer layer 14 is preferably made of metal, more preferably aluminum.

When the heat transfer layer 14 is made of metal, the emissivity of the heat transfer layer 14 is lower than that of the case where the heat transfer layer 14 is made of a carbon material or the like. Therefore, the heat absorption by the heat transfer layer 14 can be reduced, and the heat transfer in the thickness direction can be reduced by the heat transfer layer 14. As a result, the heat insulating property can be further improved.

The heat transfer layer 14 is thinner than the heat insulating layer 13. The thickness of the heat transfer layer 14 is, for example, 0.001 mm or more, preferably 0.010 mm or more, and for example, 1.0 mm or less, preferably 0.5 mm or less.

(2-5) Seal member As shown in FIG. 4, the seal member 15A is arranged on the inner surface S11 of the edge 3A of the side wall 2. With the battery cover 1 attached to the battery 100, the seal member 15A is arranged between the edge 3A of the side wall 2 and the side surface S3 of the battery 100 in the thickness direction. The seal member 15A is elastically deformable. With the battery cover 1 attached to the battery 100, the sealing member 15A seals between the edge 3A of the side wall 2 and the side surface S3 of the battery 100. As a result, it is possible to suppress the inflow of air around the battery 100 between the edge 3A of the side wall 2 and the side surface S3 of the battery 100, and it is possible to suppress the transfer of ambient heat to the battery 100.

Examples of the material of the sealing member 15A include the above-mentioned heat insulating material. The sealing member 15A is preferably made of a foam-based heat insulating material, more preferably urethane foam.

The seal member 15A is softer than the heat insulating layer 13. The 50% compression hardness of the sealing member 15A is lower than the 50% compression hardness of the heat insulating layer 13. The 50% compressive hardness of the sealing member 15A is, for example, less than 10.0 kPa, preferably 8.0 kPa or less, more preferably 6.0 kPa or less, and for example, 1.0 kPa or more, preferably 1.5 kPa. As mentioned above, more preferably 2.0 kPa or more. When the 50% compression hardness of the seal member 15A is not more than the above upper limit value, the seal member 15A can be easily deformed when the battery cover 1 is attached to the battery 100. As a result, the battery cover 1 can be smoothly attached to the battery 100. When the 50% compressive hardness of the seal member 15A is at least the above lower limit value, the shape of the seal member 15A can be maintained.

The thermal conductivity of the sealing member 15A is 0.045 W / (m · K) or less, preferably 0.043 W / (m · K) or less, more preferably 0.040 W / (m · K) or less, and further. It is preferably 0.035 W / (m · K) or less, more preferably 0.033 W / (m · K) or less, still more preferably 0.030 W / (m · K) or less, for example, 0. It is 015 W / (m · K) or more.

With the battery cover 1 removed from the battery 100, the thickness of the seal member 15A is, for example, 1 mm or more, preferably 5 mm or more, for example, 15 mm or less, preferably 10 mm or less. When the thickness of the seal member 15A is equal to or greater than the above lower limit, the amount of deformation of the seal member 15A can be secured when the battery cover 1 is attached to the battery 100, and the attachability of the battery cover 1 to the battery 100 can be improved. Can be improved. When the thickness of the seal member 15A is not more than the above upper limit value, it is possible to prevent the battery cover 1 from becoming excessively large.

Further, with the battery cover 1 removed from the battery 100, the width of the seal member 15A in the first direction is, for example, 3 mm or more, preferably 7 mm or more, for example, 15 mm or less, preferably 10 mm or less. be. When the width of the seal member 15A in the first direction is equal to or larger than the above lower limit value, the sealing performance of the seal member 15A (air around the battery 100 flows between the edge 3A of the side wall 2 and the side surface S3 of the battery 100). Performance to suppress this) can be ensured. When the width of the seal member 15A in the first direction is equal to or less than the above upper limit value, it is possible to prevent the battery cover 1 from becoming excessively large.

The seal member 15B is arranged on the inner surface S11 of the edge 3B of the side wall 2. With the battery cover 1 attached to the battery 100, the seal member 15B is arranged between the edge 3B of the side wall 2 and the side surface S3 of the battery 100 in the thickness direction. The seal member 15B is elastically deformable. With the battery cover 1 attached to the battery 100, the sealing member 15B seals between the edge 3B of the side wall 2 and the side surface S3 of the battery 100.

The description of the seal member 15B is the same as the description of the seal member 15A. Therefore, the description of the seal member 15B will be omitted.

(3) Positional relationship between the battery cover and the heat source Next, the positional relationship between the battery cover 1 and the heat source H will be described.

In the present embodiment, the battery 100 to which the battery cover 1 is attached is arranged in the engine room of the automobile.

As shown in FIG. 4, an engine as an example of the heat source H is arranged in the engine room. As the heat source in the engine room, for example, a radiator, a motor when the automobile is a hybrid vehicle, or the like is assumed. The heat source H is the heat source having the highest temperature among the heat sources in the engine room. The heat source H is arranged away from the battery 100 and the battery cover 1.

In the present embodiment, the first side wall 2A of the battery cover 1 is arranged between the heat source H and the battery 100. The heat insulating layer 13 of the first side wall 2A is defined as the first portion 13A of the heat insulating layer 13. That is, the heat insulating layer 13 has the first portion 13A. The first portion 13A is arranged between the heat source H and the battery 100.

The second side wall 2B of the battery cover 1 is arranged on the opposite side of the heat source H with respect to the battery 100. The second side wall 2B of the battery cover 1 is arranged on the opposite side of the first side wall 2A of the battery cover 1 with respect to the battery 100. The heat insulating layer 13 of the second side wall 2B is defined as the second portion 13B of the heat insulating layer 13. That is, the heat insulating layer 13 has a second portion 13B. The second portion 13B is arranged on the opposite side of the heat source H with respect to the battery 100. The second portion 13B is arranged on the opposite side of the first portion 13A with respect to the battery 100. The second portion 13B is separated from the first portion 13A. The second portion 13B may be a portion separated from the first portion 13A and having a lower temperature than the first portion 13A, and is limited to a portion arranged on the opposite side of the heat source H with respect to the battery 100. not. The distance between the second portion 13B and the heat source H is longer than the distance between the first portion 13A and the heat source H.

As described above, as shown in FIG. 3, the heat transfer layer 14 transfers heat between the first side wall 2A and the second side wall 2B. That is, the heat transfer layer 14 transfers heat between the first portion 13A and the second portion 13B. The heat of the first portion 13A heated by the heat source H is transferred to the second portion 13B whose temperature is lower than that of the first portion 13A by the heat transfer layer 14. As a result, it is possible to suppress the heat of the first portion 13A from being transferred to the battery 100. As a result, the temperature rise of the battery 100 can be suppressed.

5. Action Effect (1) As shown in FIG. 4, the battery cover 1 includes a heat insulating layer 13 and a heat transfer layer 14 having a thermal conductivity of 0.5 W / (m · K) or more.

Therefore, when the first portion 13A is heated by the heat source H while the battery cover 1 is attached to the battery 100, the heat of the first portion 13A is transferred to the first portion by the heat transfer layer 14 (see FIG. 3). It can be efficiently transmitted to the second portion 13B away from 13A.

Thereby, even if the thickness of the battery cover 1 is not increased, the heat from the heat source H can be suppressed from being transferred to the battery 100 by transferring the heat of the first portion 13A to the second portion 13B.

As a result, it is possible to improve the heat insulating property while suppressing the increase in the thickness of the battery cover 1.

(2) According to the battery cover 1, the heat transfer layer 14 is made of metal.

Therefore, the heat insulating property of the battery cover 1 can be further improved.

(3) According to the battery cover 1, the thickness of the heat insulating layer 13 is 1 mm or more.

Therefore, the heat insulating property of the battery cover 1 can be ensured.

(4) According to the battery cover 1, as shown in FIG. 4, the sealing

members

15A and 15B seal between the

edges

3A and 3B of the side wall 2 and the side surface S3 of the battery 100.

Thereby, the air heated by the heat source H can be suppressed from entering between the battery cover 1 and the battery 100 by the sealing

members

15A and 15B.

As a result, the heat insulating property of the battery cover 1 can be further improved.

(5) According to the battery cover 1, as shown in FIG. 4, the heat transfer layer 14 is arranged between the side surface S3 of the battery 100 and the heat insulating layer 13.

(6) According to the battery cover 1, as shown in FIG. 4, the distance between the second portion 13B and the heat source H is longer than the distance between the first portion 13A and the heat source H.

Therefore, the heat of the first portion 13A can be transferred to the second portion 13B away from the heat source H.

(7) According to the battery cover 1, as shown in FIG. 4, the second portion 13B is arranged on the opposite side of the first portion 13A with respect to the battery 100.

Therefore, the heat of the first portion 13A can be transferred to the battery 100 to the opposite side of the first portion 13A.

6. Modification Example Hereinafter, a modification of the battery cover 1 will be described. In the description of the modification, the same members as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted.

(1) The shape of the battery cover 1 is not limited. The shape of the battery cover 1 can be appropriately changed according to the shape of the battery. For example, when the battery has a cylindrical shape, the battery cover 1 may have a cylindrical shape. Further, when the battery has a flat shape such as a flat plate shape, the battery cover 1 has a first side wall and a second side wall, and the battery may be sandwiched between the first side wall and the second side wall.

(2) The inner surface S11 of the battery cover 1 may be in contact with the side surface S3 of the battery 100.

(3) The battery cover 1 may have a recess for avoiding interference with a member arranged around the battery 100.

(4) As shown in FIGS. 5 to 13, the arrangement of the heat transfer layer 14 is not limited as long as heat can be transferred from the first portion 13A to the second portion 13B of the heat insulating layer 13.

For example, as shown in FIG. 5, the heat transfer layer 14 may be provided on all of the side walls 2.

Further, the heat transfer layer 14 may be provided on the first side wall 2A and one of the side walls in the second direction, and may not be provided on the other side walls. Specifically, as shown in FIG. 6, the heat transfer layer 14 may be provided on the first side wall 2A and the fourth side wall 2D, and may not be provided on the second side wall 2B and the third side wall 2C. ..

Further, the heat transfer layer 14 may be provided on at least one side wall of the battery cover 1 in the second direction, and may not be provided on the other side wall. Specifically, as shown in FIG. 7, it may be provided on the third side wall 2C and the fourth side wall 2D, and may not be provided on the first side wall 2A and the second side wall 2B. Further, as shown in FIG. 8, it may be provided on the third side wall 2C and may not be provided on the first side wall 2A, the second side wall 2B, and the fourth side wall 2D.

Further, as shown in FIG. 9, the heat transfer layer 14 may be provided on the first side wall 2A only at both ends in the second direction.

Further, as shown in FIGS. 10 and 11, the battery cover 1 may have two heat transfer layers 141 and 142 separated from each other in the first direction. The heat transfer layers 141 and 142 extend in a direction intersecting the first direction. As shown in FIGS. 12 and 13, the two heat transfer layers 141 and 142 may be connected via the heat transfer layer 143 extending in the first direction.

(5) As shown in FIG. 14, the heat transfer layer 14 may be arranged on the opposite side of the side surface S3 of the battery 100 with respect to the heat insulating layer 13 in the thickness direction. As shown in FIG. 15, the battery cover 1 has a heat insulating layer 13 and a second heat insulating layer 16 that overlaps the heat insulating layer 13, and the heat transfer layer 14 is between the heat insulating layer 13 and the second heat insulating layer 16. May be placed in.

(6) The above-mentioned modifications can be combined as appropriate.

Next, the present invention will be described based on Examples and Comparative Examples. The present invention is not limited to the following examples. In addition, specific numerical values such as physical property values and parameters used in the following description are the upper limit values such as physical property values and parameters described in the above-mentioned "mode for carrying out the invention" (corresponding to them). It can be replaced with a lower limit (a number defined as "less than or equal to") or a lower limit (a number defined as "greater than or equal to").

1. 1. Material of heat insulating layer The following materials were prepared as the material of the heat insulating layer.

(1) Urethane foam Urethane foam A (thermal conductivity: 0.0400 W / m · K, thickness: 15 mm, density: 16 kg / m ³ )
Urethane foam B (thermal conductivity: 0.0409 W / m · K, thickness: 3 mm, density: 25 kg / m ³ , glue thickness: 65 μm (acrylic))
Urethane foam C (thermal conductivity: 0.0409 W / m · K, thickness: 4 mm, density: 25 kg / m ³ )
Urethane foam D (thermal conductivity: 0.0409 W / m · K, thickness: 5 mm, density: 25 kg / m ³ , glue thickness: 65 μm (acrylic))
(2) Phenolic foam (thermal conductivity: 0.02 W / m · K, thickness 12 mm, density: 40 kg / m ³ )
(3) Plastic corrugated cardboard (thermal conductivity: 0.037 W / m · K, thickness: 2.5 mm, basis weight: 550 g / m ² )
2. 2. Materials for heat transfer layer The following materials were prepared as materials for the heat transfer layer.

(1) Aluminum foil A (thickness: 11 μm, thermal conductivity: 200 W / m · K)
(2) Aluminum foil B (thickness: 100 μm, thermal conductivity: 200 W / m · K)
(3) Graphite sheet (trade name: TG828CR, manufactured by NeoGraf, thermal conductivity in the plane direction: 1400 W / m · K)
(4) Acrylic foam (thickness: 0.4 mm, thermal conductivity: 3 W / m · K)
(5) Steel (thickness: 100 μm, thermal conductivity: 50 W / m · K)
(6) Thermal conductive tape A (thickness: 100 μm, thermal conductivity: 0.4 W / m · K, TR5310EX, manufactured by Nitto Denko KK)
(7) Thermal conductive tape B (thickness: 250 μm, thermal conductivity: 0.7 W / m · K, TR5325FEX, manufactured by Nitto Denko KK)
2. 2. Configuration of Evaluation Device As shown in FIG. 16A, the evaluation device 110 includes a constant temperature bath 111, a partition wall 112, and a resin plate 113.

As the constant temperature bath 111, "SH-641" manufactured by Espec was used.

The partition wall 112 is arranged in the constant temperature bath 111. The partition wall 112 partitions the internal space of the constant temperature bath 111. Hot air is supplied to the space 111A on one side of the partition wall 112 by a fan of the constant temperature bath 111. Hot air is not supplied to the space 111B on the other side of the partition wall 112. The partition wall 112 is made of phenolic foam having a total thickness of 33 mm. The partition wall 112 has an opening 112A. The opening 112A is square. The dimension of one side of the opening 112A is 200 mm.

The resin plate 113 is a heat insulating target. The resin plate 113 is assumed to be the battery case 101 (see FIG. 2) of the battery 100 described above. The resin plate 113 is attached to the partition wall 112. The resin plate 113 closes the opening 112A. The resin plate 113 is made of polypropylene. The thickness of the resin plate 113 is 2 mm. The resin plate 113 has a first surface S41 on the space 111A side and a second surface S42 on the space 111B side.

3. 3. Examples and Comparative Examples <Examples 1 to 10 and Comparative Examples 1 to 4>
As shown in FIG. 16A, the heat insulating layer 13 and the heat transfer layer 14 shown in Table 1 are arranged in the order of the heat insulating layer 13, the heat transfer layer 14, and the resin plate 113 in the direction from the space 111A to the space 111B. It was attached to the partition wall 112. The heat insulating layer 13 has a first surface S51 on the space 111A side and a second surface S52 on the space 111B side. The heat transfer layer 14 comes into contact with the second surface S52 of the heat insulating layer 13. The resin plate 113 comes into contact with the heat transfer layer 14.

Next, from the state where the temperature inside the constant temperature bath 111 is normal temperature (25 ° C), the constant temperature tank 111 is operated at a constant value with the set temperature of the constant temperature tank 111 set to 80 ° C, and the K thermoelectric defined in JIS C 1602: 2015 is operated. Using a pair, the temperature T1 of the second surface S52 of the heat insulating layer 13 and the temperature T2 of the second surface S42 of the resin plate 113 were measured. The temperatures T1 and T2 are average values of the temperatures at the five points P1 to P5 shown in FIG. 16B.

Table 1 shows the temperature T0, the temperature T1, T2, the difference ΔT between the temperature T2 and the temperature T0 in the space 111A, and the effect of the heat transfer layer.

The effect of the heat transfer layer of each Example and Comparative Example 3 is calculated by the following formula based on the comparative example having the same heat insulating layer and no heat transfer layer.

Effect of heat transfer layer = (ΔT of Example-ΔT of Comparative Example) / ΔT of Comparative Example × 100
For example, taking Examples 1, 2 and 4 as an example, the effect of the heat transfer layer is calculated by the following formula.

Effect of heat transfer layer of Example 1 = (ΔT of Example 1-ΔT of Comparative Example 1) / ΔT of Comparative Example 1 × 100
Effect of heat transfer layer of Example 2 = (ΔT of Example 2 − ΔT of Comparative Example 1) / ΔT × 100 of Comparative Example 1
Effect of heat transfer layer of Example 4 = (ΔT of Example 4 − ΔT of Comparative Example 2) / ΔT × 100 of Comparative Example 2

<Examples 11 and 12 and Comparative Example 5>
As shown in FIG. 17A, the heat transfer layer 13 and the heat transfer layer 14 shown in Table 1 are arranged in the order of the heat transfer layer 14, the heat transfer layer 13, and the resin plate 113 in the direction from the space 111A to the space 111B. The temperatures T1 and T2 were measured in the same manner as in Example 1 except that they were attached to the partition wall 112. Table 2 shows the effects of the temperatures T0 to T2, the difference ΔT between the temperature T1 and the temperature T0, and the heat transfer layer.

<Examples 13 to 15 and Comparative Examples 6 to 8>
As shown in FIG. 17B, the heat insulating layer 13, the heat transfer layer 14, and the second heat transfer layer 16 shown in Table 1 are arranged in the direction from the space 111A to the space 111B, and the heat insulating layer 13, the heat transfer layer 14, and the second heat transfer layer 16. The temperatures T1 and T2 were measured in the same manner as in Example 1 except that the heat insulating layer 16 and the resin plate 113 were attached to the partition wall 112 in this order. Table 3 shows the effects of the temperatures T0 to T2, the difference ΔT between the temperature T1 and the temperature T0, and the heat transfer layer.

The above invention has been provided as an exemplary embodiment of the present invention, but this is merely an example and should not be construed in a limited manner. Modifications of the invention that are apparent to those skilled in the art are included in the claims below.

The battery cover of the present invention is used to suppress the transfer of ambient heat to the battery.

1 Battery cover 2 Side wall 3A Edge 13 Insulation layer 13A 1st part 13B 2nd part 14 Heat transfer layer 15A Seal member 100 Battery H Heat source S3 Side surface

Claims

A heat insulating layer having a first portion and a second portion separated from the first portion.
It is provided with a heat transfer layer that transfers heat between the first portion and the second portion and has a higher thermal conductivity than the heat insulating layer.
A battery cover characterized in that the thermal conductivity of the heat transfer layer is 0.5 W / (m · K) or more.
The battery cover according to claim 1, wherein the heat transfer layer is made of metal.
The battery cover according to claim 1 or 2, wherein the heat insulating layer has a thickness of 1 mm or more.
The battery cover according to any one of claims 1 to 3, characterized in that it is removable from the battery.
The battery cover according to claim 4, wherein the side wall covers the side surface of the battery and includes the side wall having the heat insulating layer and the heat transfer layer.
The sidewalls face the sides of the battery at a distance from each other.
The battery cover is
The battery cover according to claim 5, further comprising a sealing member that seals between the edge of the side wall and the side surface of the battery.
The battery cover according to claim 5 or 6, wherein the heat transfer layer is arranged between the side surface of the battery and the heat insulating layer.
The battery cover according to any one of claims 4 to 7, wherein the first portion is arranged between a heat source arranged away from the battery and the battery.
The battery cover according to claim 8, wherein the distance between the second portion and the heat source is longer than the distance between the first portion and the heat source.
The battery cover according to any one of claims 4 to 9, wherein the second portion is arranged on the opposite side of the first portion with respect to the battery.