JP6894379B2 - Thermally conductive thermally expandable resin composition, thermally conductive thermally expandable molded article, battery module, and battery pack - Google Patents

Description

The present invention relates to a heat conductive heat expandable resin composition, a heat conductive heat expandable molded body, a battery module, and a battery pack.

In various batteries typified by lithium batteries, thermal runaway may occur at high temperatures, causing disasters such as ignition and smoking. In order to minimize disasters, it is important to take measures to make it difficult to transfer the heat of the abnormally high temperature battery to the surrounding batteries and the housing containing the batteries. On the other hand, it is also important to ensure the heat dissipation of the battery during normal use of the battery.

Patent Document 1 includes a fire control agent installed between a shell and one or more battery cells, and the fire control agent is between one or more battery cells and a shell surrounding the one or more battery cells. A battery pack containing a thermal expansion agent that fills the space and can prevent, suppress and / or extinguish ignition in the battery pack is described. The fire control agent is applied to the inner surface of the shell.

Japan Special Table 2015-518638

However, the fire control agent of Patent Document 1 shows only heat-expandable graphite, and the fire control agent does not start expansion unless the temperature becomes relatively high.

An object of the present invention is thermal conductivity, which has excellent heat dissipation during normal operation and exhibits heat insulating performance capable of starting expansion at a relatively low temperature at an abnormally high temperature and preventing ignition due to a thermal chain to an adjacent battery. It is an object of the present invention to provide a resin composition, a heat conductive heat expandable molded body, a battery module, and a battery pack.

As a result of diligent studies to achieve the above object, the present inventors have found that the above problems can be solved by using a thermally conductive and thermally expandable resin composition having the following constitution, and complete the present invention. I arrived.

That is, the present invention includes the subjects described in the following sections.
Item 1. It has a thermal conductivity of 1 W / m · K or more at -30 ° C to 80 ° C, starts expansion at a temperature exceeding 80 ° C, and has a thermal conductivity of 0.5 W / m · K or less after thermal expansion. A heat-expandable resin composition.
Item 2. Item 2. The heat-conducting heat-expandable resin composition according to Item 1, which contains a heat-conducting filler.
Item 3. Item 2. The thermally conductive thermally expandable resin composition according to Item 1 or 2, which contains an expandable material.
Item 4. A heat-conducting heat-expandable molded product formed from the heat-conducting heat-expandable resin composition according to any one of Items 1 to 3.
Item 5. Item 2. The thermally conductive and thermally expandable molded article according to Item 4, which has a heat radiating portion on one surface.
Item 6. Heat that has a thermal conductivity of 1 W / m · K or more at -30 ° C to 80 ° C, starts expansion at a temperature exceeding 80 ° C, and has a thermal conductivity of 0.5 W / m · K or less after thermal expansion. Conductive thermal expansion sheet.
Item 7. Item 6. The thermally conductive thermally expandable sheet according to Item 6, which has an expansion rate of 60 seconds or less.
Item 8. A coating material containing the thermally conductive and thermally expandable resin composition according to any one of Items 1 to 3.
Item 9. A battery module including a plurality of battery cells and a housing for accommodating the plurality of battery cells.
Item 3. The layer made of the heat conductive heat expandable resin composition according to any one of Items 1 to 3, the heat conductive heat expandable molded body according to Item 4 or 5, or the item. A battery module in which the heat conductive and heat expandable sheet according to 6 or 7 is arranged.

Item 10. A battery module including a plurality of battery cells and a housing for accommodating the plurality of battery cells, and a surface having the heat radiating portion on the surface of the battery cell is a surface to be attached to the surface of the battery cell. The layer made of the heat conductive heat expandable resin composition according to any one of Items 1 to 3, the heat conductive heat expandable molded body according to Item 4 or 5, or the item. A battery module in which the heat conductive and heat expandable sheet according to 6 or 7 is arranged, and a space is provided between adjacent battery cells to enable air flow.
Item 11. Item 3. The item according to any one of Items 1 to 3, wherein the battery module includes a plurality of battery cells and a housing for accommodating the plurality of battery cells, and is provided on the inner surface, the outer surface, or both of the housings. A battery in which a layer made of a heat conductive heat expandable resin composition, a heat conductive heat expandable molded body according to Item 4 or 5, or a heat conductive heat expandable sheet according to Item 6 or 7 is arranged. module.
Item 12. Item 9. The battery module according to any one of Items 9 to 11, an electric connection cable electrically connected to each of the plurality of battery modules, and a housing for accommodating the plurality of battery modules and the electric connection cable. A battery pack provided in which the layer made of the heat conductive heat expandable resin composition or the heat conductive heat expandable molded body is a space between a battery cell and a battery cell, and a battery cell and a battery module. The space between the housing, the space inside the battery module housing, the space between the battery module and the battery module, the space between the battery module and the battery pack housing, and the space inside the battery pack housing. Battery packs installed in one or more of these locations.

According to the present invention, the heat dissipation property of the battery cell in a normal state and the heat insulating property at an abnormally high temperature are improved, and the safety of the battery pack can be enhanced.

FIG. 6 is a schematic vertical sectional view of the battery module of the first embodiment. FIG. 6 is a schematic vertical sectional view of a battery pack including the battery module of FIG. FIG. 3 is a schematic perspective view of a laminate composed of a thermally conductive heat-expandable sheet provided with (A) concave portions, (B) convex portions, and (C) uneven portions as heat radiating portions, and a battery cell. FIG. 3 is a schematic perspective view of a laminate composed of a thermally conductive thermally expandable sheet having fins as a heat radiating portion and a battery cell. FIG. 3 is a schematic perspective view of a laminate composed of a thermally conductive thermally expandable sheet having ribs as a heat radiating portion and a battery cell. (A) A schematic perspective view of another example battery cell, (B) a cross-sectional view taken along the line 6B-6B of FIG. 6 (A). FIG. 6 is a schematic vertical sectional view of a battery module including the battery cell of FIG. Schematic cross-sectional view of another example battery module. Schematic cross-sectional view of another example battery module. Schematic cross-sectional view of another example battery module. FIG. 6 is a schematic vertical sectional view of the battery module of the second embodiment. FIG. 4 is a schematic vertical sectional view of a battery pack including the battery module of FIG. FIG. 6 is a schematic perspective view of another example of a heat conductive and heat expandable molded product. FIG. 6 is a schematic perspective view of another example of a heat conductive and heat expandable molded product.

In the present invention, the battery is a lithium ion battery, a lithium ion polymer battery, a nickel / hydrogen battery, a lithium / sulfur battery, a nickel / cadmium battery, a nickel / iron battery, a nickel / zinc battery, a sodium / sulfur battery, a lead storage battery, and air. It means a secondary battery such as a battery.

The lithium ion battery is classified into a cylindrical type, a square type, and a laminated type according to the shape of the cell.

In the present specification, the “battery cell” refers to a constituent unit of a battery in which a positive electrode material, a negative electrode material, a separator, a positive electrode terminal, a negative electrode terminal, and the like are housed in an exterior member.

When the battery cell has a cylindrical shape, it refers to a constituent unit of a battery in which a positive electrode material, a negative electrode material, a separator, a positive electrode terminal, a negative electrode terminal, an insulating material, a gas discharge valve, a gasket, a positive electrode cap, etc. are housed in an outer can.

When the battery cell has a square shape, it refers to a constituent unit of a battery in which a positive electrode material, a negative electrode material, a separator, a positive electrode terminal, a negative electrode terminal, an insulating material, a gas discharge valve, and the like are housed in an outer can.

When the battery cell is a laminated type, it refers to a constituent unit of a battery in which a positive electrode material, a negative electrode material, a separator, a positive electrode terminal, a negative electrode terminal, and the like are housed in an exterior film. Examples of the exterior film include an aluminum film on which a polyethylene terephthalate film is laminated.

In the present specification, the “battery module” refers to a structural unit of a battery in which a plurality of battery cells are housed in a housing. A "battery pack" refers to a housing containing a plurality of battery modules. Inside the battery module and the battery pack, in addition to the battery cell, necessary members such as an electric connection cable electrically connected to the battery cell are used as needed.

Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a schematic vertical sectional view of the battery module of the first embodiment.

In the housing 2 of the battery module 1 of the first embodiment, a plurality of battery cells 3 (three are shown in the figure) are housed side by side so as to be separated from each other and extend in the vertical direction, and adjacent batteries are accommodated. Between the cells 3, a heat conductive heat expandable sheet 4 as a heat conductive heat expandable molded body obtained by molding the heat conductive heat expandable resin composition into a sheet shape is arranged.

The surface of one battery cell 3 is usually formed of an aluminum sheet on which a PET film is laminated, a metal having a cylindrical shape or a square shape, or the like. Examples of the method of installing the heat conductive heat expandable sheet 4 on a part or all of at least one surface (for example, one side or a pair of both sides) of the battery cell 3 include the following methods. One method is to attach and fix the heat conductive heat expandable sheet 4 to the surface of one battery cell 3 via an adhesive material or by the self-adhesiveness of the heat conductive heat expandable sheet 4. is there. Another method is a method in which the battery cell 3 and the heat conductive and heat expandable sheet 4 are laminated and then fixed using a frame.

The thermally conductive thermally expandable resin composition constituting the thermally conductive thermally expandable sheet 4 has a thermal conductivity of 1 W / m · K or more at −30 ° C. to 80 ° C. and expands at a temperature exceeding 80 ° C. It is a thermally conductive and thermally expandable resin composition having a thermal conductivity of 0.5 W / m · K or less after starting and thermally expanding. The thermally conductive thermally expandable resin composition preferably starts expansion at a temperature of 100 ° C. or higher.

Therefore, the heat conductive and heat expandable sheet 4 has excellent heat dissipation during normal use of the battery, and can satisfactorily dissipate the heat generated by the operation of the battery cell 3. Further, the heat conductive heat expandable sheet 4 starts to expand even at a relatively low temperature when the heat conductive heat expandable sheet 4 is heated due to abnormal heat generation or fire, and becomes a space serving as a flow path for fire and heat. And forms a heat insulating layer between adjacent battery cells 3. Therefore, heat transfer, heat conduction and / or ignition from one battery cell 3 to the adjacent battery cell 3 can be prevented, suppressed, or delayed, and the safety of the battery is ensured.
Further, the heat conductive heat expandable sheet 4 has a heat conductivity of 1 W / m · K or more at −30 ° C. to 80 ° C., and even when heat is generated locally in the battery cell 3, for example, the heat is conducted. It also has the feature of being able to diffuse in the plane direction of the heat-expandable sheet 4 and / or in the direction perpendicular to the sheet 4. This makes it possible to suppress local deterioration due to heat spots in the battery cell 3, for example.

The size of the heat conductive heat expandable sheet 4 is not particularly limited and varies depending on the size of the battery cell 3 and the size of the space in the battery module 1, but the thickness of the heat conductive heat expandable sheet 4 Is normal, that is, the temperature of −30 ° C. to 80 ° C. is 2 mm or less, and when it exceeds 80 ° C., it is preferably 2 mm or more.

The thermally conductive thermally expandable resin composition contains a resin component, a thermally conductive filler, and an expandable material.

[Resin component]
Examples of the resin component include thermoplastic resins, thermosetting resins, elastomer resins, and combinations thereof.

Examples of the thermoplastic resin include polyolefin resins (PO) such as polypropylene resin, polyethylene resin (PE), poly (1-) butene resin, and polypentene resin, polystyrene resin, acrylonitrile-butadiene-styrene (ABS) resin, and ethylene. -Vinyl acetate copolymer (EVA), polycarbonate resin, polyphenylene ether resin, (meth) acrylic resin, polyamide resin, polyvinyl chloride resin (PVC), chlorinated polyvinyl chloride resin (CPVC), novolak resin, polyurethane resin , Synthetic resin such as polyisobutylene resin.

Examples of the thermosetting resin include synthetic resins such as polyurethane resin, polyisocyanate resin, polyisocyanurate resin, phenol resin, epoxy resin, urea resin, melamine resin, unsaturated polyester resin, silicone resin, and polyimide. ..

Elastol resins include acrylonitrile butadiene rubber, liquid acrylonitrile butadiene rubber, ethylene-propylene-diene rubber (EPDM), liquid ethylene-propylene-diene rubber (liquid EPDM), ethylene-propylene rubber, liquid ethylene-propylene rubber, natural rubber, and liquid natural. Rubber, polybutadiene rubber, liquid polybutadiene rubber, polyisoprene rubber, liquid polyisoprene rubber, styrene-butadiene block copolymer, liquid styrene-butadiene block copolymer, hydrogenated styrene-butadiene block copolymer, liquid hydrogenated styrene- Butadiene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, liquid hydrogenated styrene-butadiene-styrene block copolymer, hydrogenated styrene-isoprene block copolymer, liquid hydrogenated styrene-isoprene block copolymer Examples thereof include coalescence, hydrogenated styrene-isoprene-styrene block copolymer, and liquid hydrogenated styrene-isoprene-styrene block copolymer. Among these, acrylonitrile butadiene rubber, liquid acrylonitrile butadiene rubber and ethylene-propylene-diene rubber, liquid ethylene-propylene-diene rubber, and butyl rubber (isobutylene-isoprene rubber) are preferable.

As these thermoplastic resins, thermosetting resins, and / or elastomer resins, one kind or two or more kinds can be used. A resin composition capable of dispersing the filler at 80 ° C. or lower is more preferable.

Among these thermoplastic resins, thermosetting resins, and / or elastomer resins, those having soft and rubbery properties or those having a low viscosity are preferable. The resin component having such properties can be highly filled with a filler, an expandable material, or the like. Further, since the rubbery substance has self-adhesiveness, the heat conductive heat expandable sheet 4 does not need to use an adhesive or an adhesive means such as an adhesive sheet between the battery cell 3 and the heat conductive heat expandable sheet 4. Can be attached to the battery cell 3.

Thermoplastic resins, thermosetting resins, and / or elastomeric resins also include these resins produced by chemical reaction in a monomeric state and these resins produced by polymerization by electron beam cross-linking. It is preferable that the thermally conductive and thermally expandable composition can be highly filled with a filler or the like at a low temperature.

The total amount of the thermoplastic resin, the thermosetting resin, and / or the elastomer resin is preferably 2 to 90% by volume, more preferably 30 to 80% by volume in the heat conductive heat-expandable composition. preferable. When it is 2% by volume or more, it is easy to mix with other components, and when it is 90% by volume or less, it is easy to impart thermal conductivity.

[Thermal conductive filler]
The thermally conductive filler functions to impart thermal conductivity to the thermally conductive thermally expandable resin composition. Preferred thermally conductive filler, silica, alumina, aluminum nitride, silicon nitride, boron nitride, silicon carbide, beryllium oxide, magnesium oxide, diamond, carbon nanotubes (CNT), boron nitride nanotubes (BNNTs), talc, Graphite, grayed Rafen, acetylene black, kickback black, fibrous carbon material and aluminum, copper, metal powder or the like such as silver and gold and the like. One of these thermally conductive fillers may be used alone, or two or more thereof may be mixed and used.

The thermal conductivity of the thermally conductive filler is preferably 1 W / m · K or more, more preferably 5 W / m · K or more, further preferably 10 W / m · K or more, and most preferably 20 W / m · K or more. When the thermal conductivity is within the above range, the thermal conductivity of the thermally conductive thermally expandable resin composition and the thermally conductive thermally expandable molded body formed from the composition becomes sufficiently high.

The average particle size of the thermally conductive filler is preferably 0.001 to 3000 μm, preferably 0.001 to 300 μm, from the viewpoints of heat dissipation, moldability, processability, maintenance of mechanical properties of the resin composition, and the like. Is more preferable, and 0.001 to 100 μm is further preferable. The upper limit is further preferably 50 μm or less. When the particle size of the heat conductive filler is within the above range, a good heat conductive heat expandable resin composition can be obtained. The average particle size can be calculated as an average value of 5 times measured by a laser diffraction / scattering type particle size distribution measuring device (HELOS BFM, manufactured by Sympatec GmbH).

The content of the thermally conductive filler is preferably 10 to 3500 parts by mass, more preferably 10 to 2000 parts by mass, further preferably 10 to 1000 parts by mass, and further preferably 10 to 850 parts by mass with respect to 100 parts by mass of the resin component. Preferably, 10 to 700 parts by mass is most preferable. When the content of the thermally conductive filler is within the above range, sufficient thermal conductivity can be imparted while sufficiently mixing the components with the thermally conductive thermally expandable composition.

The content of the heat conductive filler in the heat conductive heat expandable resin composition is usually 2 to 90% by volume, preferably 10 to 80% by volume. When it is 10% by volume or more, the heat dissipation effect is good, and when it is 90% by volume or less, the moldability is good.

[Expandable material]
The expandable material forms a heat insulating layer by expanding when the heat conductive heat expandable sheet 4 is heated due to abnormal heat generation, fire, or the like. For this reason, it functions to block the space serving as a flow path for fire and heat, and to divide the percolation (heat conduction path) of the heat conductive filler to reduce the heat conductivity.

Examples of the expandable material include heat-expandable microcapsules, water-containing microcapsules, foaming agents, microencapsulated foaming agents, heat-expandable layered inorganic substances, and combinations thereof.

The heat-expandable microcapsules are formed in a shell formed of a plastic polymer obtained by polymerizing a composition containing one or more kinds of monomers and a cross-linking agent, and have a temperature below the softening point of the polymer. It contains a volatile swelling agent that becomes gaseous. Examples of the synthetic resin used for such a plastic polymer include a thermoplastic synthetic resin having a viscosity that melts when the temperature rises above a certain level and the heat-expandable microcapsules do not crack and expand substantially spherically. For example, WO 2010/052972 comprises a polymer obtained by polymerizing a monomer mixture in which the shell contains 95% by weight or more of (meth) acrylonitrile and 70% by weight or more of (meth) acrylonitrile is acrylonitrile. And the heat-expandable microcapsules having a degree of cross-linking of 60% by weight or more are described. When the polymer contains a monomer other than (meth) acrylonitrile, such monomer includes a monomer selected from the group consisting of methacrylic acid ester, acrylic acid ester, styrene, vinylidene chloride and vinyl acetate.

Examples of the volatile swelling agent include a low boiling point organic solvent and a compound which is thermally decomposed into a gas by heating and are preferably used. Among them, a low boiling point organic solvent is particularly preferably used. These volatile leavening agents may be used alone or in combination of two or more.

Examples of the low boiling point organic solvent include ethane, ethylene, propane, propene, n-butane, isobutane, n-butene, isobutane, n-pentane, isopentane, neopentane, n-hexane, heptane, nonane, decane, and petroleum. hydrocarbons such as ethers; CCl ₃ F, chlorofluorocarbons such as _{CCl 2 F 2, CClF 3,} CClF 2 -CCl 2 F 2; tetramethylsilane, trimethylethyl silane, trimethyl isopropyl silane, such as trimethyl -n- propyl silane Examples thereof include tetraalkylsilane. Among them, hydrocarbons such as n-butane, isobutane, n-pentane, isopentane, n-hexane, nonane, decane and petroleum ether can be used, and hydrocarbons having 3 to 12 carbon atoms are preferably used. Hydrocarbons having 4 or more carbon atoms are particularly preferably used. Oxygen-containing hydrocarbons and esters may also be used. These low boiling point organic solvents may be used alone or in combination of two or more.

The water-containing microcapsules are the above-mentioned microcapsules containing water.

Examples of the foaming agent include non-organic foaming agents, organic foaming agents, and combinations thereof.

Examples of the non-organic foaming agent include gas generating materials which are compounds such as water and sodium hydrogen carbonate. These non-organic foaming agents can be used alone or in combination of two or more.

Examples of the organic foaming agent include ethane, ethylene, propane, propene, n-butane, isobutane, n-butene, isobutene, n-pentane, isopentan, neopentane, n-hexane, heptane, nonane, decane, petroleum ether and the like. Hydrocarbons; azo compound-containing foaming agents such as azodicarbonamide (ADCA) and azodiaminobenzene; nitroso compounds such as dinitrosopentamethylenetetramine (DPT), N, N'-dinitroso-N, N'-dimethylterephthalamide. Containing foaming agents: sulfonyl / hydrazide-containing foaming agents such as benzenesulfonylhydrazide, p, p'-oxybisbenzenesulfonylhydrazide (OBSH), hydrazodicarbonamide (HDCA) and the like. One of these organic foaming agents or a combination of two or more of these organic foaming agents can be used.

The microencapsulated foaming agent is one or two or more of the above-mentioned foaming agents encapsulated in microcapsules. As the synthetic resin used for the microcapsules, for example, a thermoplastic synthetic resin having a viscosity that melts when the temperature rises above a certain level and the microcapsules do not crack and expand substantially spherically may be used.

By adding a microencapsulating foaming agent to the heat-conducting heat-expandable resin composition, the synthetic resin melts when the heat-conducting heat-expandable resin composition is heated to a certain temperature or higher. Therefore, the heat-conducting heat-expandable resin composition can be foamed.

The heat-expandable layered inorganic substance expands when heated and is not particularly limited, and examples thereof include vermiculite, kaolin, mica, and heat-expandable graphite. Thermally expandable graphite is a conventionally known substance that expands when heated, and powders such as natural scaly graphite, thermally decomposed graphite, and kissed graphite are treated with an inorganic acid and a strong oxidizing agent to form a graphite intercalation compound. It is a kind of crystalline compound that maintains the layered structure of carbon. Examples of the inorganic acid include concentrated sulfuric acid, nitric acid and selenic acid. Examples of the strong oxidizing agent include concentrated nitric acid, perchloric acid, perchlorate, permanganate, dichromate, dichromate, hydrogen peroxide and the like.

The heat-expandable graphite obtained by the acid treatment as described above may be further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound or the like.

The content of the expandable material in the thermally conductive thermally expandable resin composition can be appropriately set according to the expansion coefficient. The expandable material is usually 0.1 to 500 parts by mass, preferably 1 to 400 parts by mass, and more preferably 5 to 300 parts by mass with respect to 100 parts by mass of the resin component. The heat conductive heat-expandable resin composition starts to expand at a temperature exceeding 80 ° C., and the expansion coefficient in the thickness direction (thickness after expansion / thickness before expansion) is 1.5 to 50 times, preferably 2 to 2. Adjust so that it is about 30 times. Further, according to this formulation, the heat-expandable sheet or molded body formed from the heat-conductive heat-expandable resin composition expands by heating such as heat generation of the battery, and a required coefficient of thermal expansion can be obtained. Moreover, after expansion, a residue having a predetermined heat insulating performance and a predetermined strength can be formed, and stable fire protection performance can be achieved. Further, by using an expandable material having a low expansion start temperature, the thermally conductive thermally expandable resin composition can be designed to start expansion even at a relatively low temperature.

The thermally conductive, thermally expandable resin composition of the present invention may contain various additive components as necessary, as long as the object of the present invention is not impaired.

The type of this additive component is not particularly limited, and various additives usually used for foam molding can be used. Examples of such additives include lubricants, shrinkage inhibitors, bubble nucleating agents, crystal nucleating agents, plasticizers, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, antioxidants, and the above heat conduction. Examples thereof include fillers excluding bodies, reinforcing agents, flame retardants, flame retardants, antistatic agents, surfactants, lubricants, surface treatment agents and the like. The amount of the additive added can be appropriately selected within a range that does not impair the formation of bubbles and the like, and the amount of the additive used for foaming and molding a normal resin can be adopted. Such additives can be used alone or in combination of two or more.

The lubricant has the effect of improving the fluidity of the resin and suppressing the thermal deterioration of the resin. The lubricant used in the present invention is not particularly limited as long as it is effective in improving the fluidity of the resin. For example, hydrocarbon-based lubricants such as liquid paraffin, paraffin wax, microwax, polyethylene wax; fatty acid-based lubricants such as stearic acid, behenic acid, and 12-hydroxystearic acid; butyl stearate, monoglyceride stearate, pentaerythritol tetrastearate. , Hardened paraffin oil, ester-based lubricants such as stearyl stearate, mineral oil and the like.

The amount of the lubricant added is preferably about 0.01 to 50 parts by mass, more preferably 0.05 to 5 parts by mass, and further preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the resin component. .. When the addition amount is 5 parts by mass or less, the fluidity is appropriately low and a desired foaming ratio can be maintained. When the addition amount is 0.01 part by mass or more, the fluidity can be improved, the stretchability at the time of foaming is good, and the desired foaming ratio can be maintained.

Examples of the flame retardant include a bromine-based flame retardant such as decabromodiphenyl ether and a phosphorus-based flame retardant such as ammonium polyphosphate, in addition to metal hydroxides such as aluminum hydroxide and magnesium hydroxide.

Antimony compounds such as antimony trioxide, antimony tetraoxide, antimony pentoxide, sodium pyroantimonate, antimony trichloride, antimony trisulfide, antimony oxychloride, antimony trichloride, potassium dichloride, etc. , Boron compounds such as zinc metaborate, zinc tetraborate, zinc borate, basic zinc borate, zirconium oxide, tin oxide, molybdenum oxide and the like.

The heat-conducting heat-expandable sheet 4 is a single-screw extruder, a twin-screw extruder, an injection molding machine, a Banbury mixer, a kneader mixer, a kneading roll, and a raikai machine for each of the above components of the heat-conducting heat-expandable resin composition. It can be obtained by kneading using a known device such as a planetary stirrer, a calendar molding device, a rotation mixer, or a revolution mixer, and molding by a known molding method.
The heat-conducting heat-expandable resin composition can be molded into the heat-conducting heat-expandable sheet as described above, but it can also be used as a molded product, a paint, or the like.

Thermal conductivity By using the above-mentioned materials constituting the heat-expandable sheet 4 in appropriate combination, those skilled in the art have a thermal conductivity of 1 W / m · K or more at −30 ° C. to 80 ° C. and exceed 80 ° C. It is possible to manufacture the thermally conductive thermally expandable sheet 4 which starts expansion at a temperature and has a thermal conductivity of 0.5 W / m · K or less after the thermal expansion.

Further, the expansion rate of the thermally conductive thermally expandable sheet 4 is not particularly limited, but is preferably 60 seconds or less, and more preferably 10 seconds or less. The lower limit of the expansion rate is not particularly limited, but is preferably 0.01 seconds or more.

Since the expansion rate of the heat conductive heat expandable sheet 4 is 60 seconds or less, even if abnormal heat generation or the like occurs in the battery cell 3, the heat conductive heat expandable sheet 4 rapidly expands and is adjacent to the battery cell 3. It is possible to effectively suppress heat conduction and ignition to the matching battery cell 3.

The expansion rate of the heat conductive heat expandable sheet 4 is such that the heat conductive heat expandable sheet 4 is placed on a hot plate and the temperature is raised from room temperature to 200 ° C. at 30 ° C./min to obtain the heat conductive heat expandable sheet 4. Is a value obtained by measuring the time from the start of expansion to the end of expansion.
The expansion rate of the thermally conductive thermally expandable sheet 4 can be adjusted, for example, by adjusting the amount of the foaming agent or adjusting the resin viscosity.

Returning to FIG. 1, the housing 2 is, for example, a metal or resin molded housing, but is not limited thereto. The battery cell 3 and the heat-conducting heat-expandable sheet 4 are substantially rectangular parallelepipeds in the shape of a flat plate in FIG. 1, and are arranged substantially parallel to each other. For example, a space 5 is provided around the battery cell 3 and the heat conductive heat expandable sheet 4 in the housing 2, and the battery cell 3 and the heat conductive heat expandable sheet 4 adjacent to the battery cell 3 A space 6 is also provided between them. These spaces 5 and 6 act as air passages for heat dissipation of the battery cell 3. For example, the battery cell 3 may be heated during operation, but by securing such spaces 5 and 6, the battery cell 3 can dissipate heat more quickly.

When the heat conductive heat expandable sheet 4 is heated due to abnormal heat generation, fire, or the like, the heat conductive heat expandable sheet 4 expands and the thermal conductivity decreases. It is also possible to block the space 6.

The heat conductive heat expandable sheet 4 expands and functions as a heat insulating layer, and can prevent or delay heat transfer or ignition from one battery cell 3 to an adjacent battery cell 3, and the battery module 1 can be used. Ignition delay is improved and safety is ensured.

With such a configuration, the heat storage of the battery cell is reduced because the heat dissipation is excellent while ensuring the heat dissipation of the battery cell 3 and the air passage for heat dissipation in the normal state. Further, even when heat spots are locally generated in the battery cell 3, local deterioration of the battery cell 3 can be suppressed by heat diffusion in the surface direction and / and the vertical direction of the heat conductive heat expandable sheet 4. it can.

Further, at the time of abnormal heat generation or high temperature such as fire, on the contrary, since the passage space is filled with the expansion sheet having high heat insulation, heat transfer between adjacent batteries can be prevented, so that abnormal heat generation of the entire battery module 1 is generated. Safety is improved because it is suppressed.

FIG. 2 is a schematic vertical sectional view of the battery pack 10 including the battery module 1 of FIG. A plurality of battery modules 1 (two are shown in the figure) are housed in the housing 11 of the battery pack 10. The housing 11 is, for example, a metal or resin molded housing, but is not limited thereto. Further, a heat conductive and heat expandable sheet 4 is arranged between adjacent battery modules 1. Further, a plurality of battery modules 1 are arranged in series or in parallel.

When the heat conductive heat expandable sheet 4 is heated due to abnormal heat generation, fire, or the like, the heat conductive heat expandable sheet 4 expands. As a result, the space serving as the flow path for fire and heat can be filled with the heat insulating material.

With such a configuration, even in the battery pack 10 of FIG. 2, the heat conductive thermal expansion sheet is secured at the time of abnormal heat generation or high temperature such as fire while ensuring the heat dissipation of the battery cell 3 and the air passage for heat dissipation in the normal state. 4 acts as a heat insulating material. Therefore, the battery module 1 and the battery pack 10 can exhibit the ignition delay property, and can have both the heat dissipation property of the battery pack in the normal state and the safety in the case of abnormal heat generation.

Up to this point, the battery module of the first embodiment of the present invention has been described, but the present invention is not limited to this, and various modifications based on the technical idea of the present invention are possible.
The battery cell 3 and the heat conductive heat expandable sheet 4 may be in contact with each other or may be separated by a space.

A heat radiating portion for improving heat radiating property may be provided on at least one surface of the heat conductive and heat expanding sheet 4. Such a heat-dissipating portion is usually provided so that the surface having the heat-dissipating portion is on the side opposite to the surface to which one or a plurality of surfaces of the battery cell are attached.

For example, FIG. 3A shows a laminated body in which the heat conductive heat expandable sheet 4 is laminated on the battery cell 3, and is on the side opposite to the sticking surface of the battery cell 3 in the heat conductive heat expandable sheet 4. A plurality of recesses 20 as heat radiating portions are provided on the surface. In this figure, the recess 20 is provided in a substantially hemispherical shape, but other shapes may be used. By providing the recess 20 in this way, the surface area of the heat conductive heat expandable sheet 4 can be increased, and the heat dissipation of the heat conductive heat expandable sheet 4 can be improved. Hereinafter, an alternative example of the heat dissipation unit will be described.

In FIG. 3B, a plurality of convex portions 21 as heat radiating portions are provided on the surface of the thermally conductive and thermally expandable sheet 4 opposite to the surface on which the battery cell 3 is attached. In this figure, the convex portion 21 is provided in a substantially hemispherical shape, but other shapes may be used. By providing the convex portion 21 in this way, the surface area of the heat conductive heat expandable sheet 4 can be increased, and the heat dissipation of the heat conductive heat expandable sheet 4 can be improved.

As shown in FIG. 3C, the concave portion 20 and the convex portion 21 may be used together as the heat radiating portion. In this figure, the concave portions 20 and the convex portions 21 are arranged alternately, but other arrangements may be used.

As shown in FIG. 4, as the heat radiating portion, a plurality of fins 22 protruding from the surface of the heat conductive and heat expandable sheet 4 opposite to the surface on which the battery cell 3 is attached may be provided. The plurality of fins 22 are preferably formed integrally with the heat conductive heat expandable sheet 4 from the same heat conductive heat expandable resin composition as the heat conductive heat expandable sheet 4. The plurality of fins 22 extend substantially perpendicular to the surface of the heat conductive and heat expandable sheet 4 and substantially parallel to each other. Even with this configuration, the heat dissipation surface is increased, so that the heat dissipation of the heat conductive and heat expandable sheet 4 can be improved.

As shown in FIG. 5, as the heat radiating portion, a plurality of ribs 23 protruding from the surface of the heat conductive and heat expandable sheet 4 opposite to the surface on which the battery cell 3 is attached may be provided. The plurality of ribs 23 are preferably formed integrally with the heat conductive heat expandable sheet 4 from the same heat conductive heat expandable resin composition as the heat conductive heat expandable sheet 4. Each rib 23 has a substantially triangular cross section (may be a corrugated shape with rounded corners), and the apex protrudes substantially vertically from the surface of the heat conductive heat expandable sheet 4, and is one of the heat conductive heat expandable sheets 4. It extends approximately parallel to the sides. The plurality of ribs 23 have a configuration in which the ribs 23 are arranged substantially parallel to each other. Even with this configuration, the heat dissipation surface is increased, so that the heat dissipation of the heat conductive and heat expandable sheet 4 can be improved. It is also possible to carry out a treatment to increase heat radiation.

The heat-conducting heat-expandable molded body formed from the heat-conducting heat-expandable resin composition contains a heat-conductive heat-expandable resin composition in addition to the heat-conducting heat-expandable sheet 4 of the first embodiment. It can also be formed by spraying, spraying or coating, or can be molded and manufactured by spraying, spraying or coating on a release paper or the like.

The heat-conducting heat-expandable resin composition is in the form of a heat-expandable coating that covers the periphery of the battery cell 3 as shown in FIG. 6, instead of the heat-conducting heat-expandable sheet 4 of the first embodiment. It may be provided. For example, the periphery of the battery cell 3 may be coated with a heat-expandable coating 4'made of a heat-conducting heat-expandable resin composition. Further, in FIG. 6, the heat-expandable coating 4'covers the entire outer surface of the battery cell 3, but as shown in FIG. 1, one side of the battery cell 3 may be covered, or both sides may be covered. You may. The surface of the battery cell 3 may be coated with a heat-expandable coating 4'to the extent that heat transfer or ignition from the battery cell 3 to another battery cell 3 is suppressed or prevented. The heat-conducting heat-expandable resin composition is applied to the surface of the battery cell 3 by spraying, spraying, coating, etc. to cure it, or a liquid heat-conducting heat-expandable resin composition is placed in a container such as a mold or a frame material. By putting an object and immersing the battery cell 3 in such a container, a battery cell 3 having a heat-expandable coating 4'made of a heat-expandable resin composition can be obtained.

FIG. 7 shows a battery module 1 provided with such a battery cell 3. Even in such a configuration, the heat-expandable coating 4'normally promotes heat dissipation from the battery cell 3, and when the battery cell 3 is heated due to abnormal heat generation or a fire, the heat-expandable coating 4'is a battery cell. It expands around 3 to block the space 6 between the battery cells 3 and acts as a heat insulating material. Therefore, heat transfer or ignition from one battery cell 3 to the adjacent battery cell 3 can be prevented or delayed, and the safety of the battery module 1 is ensured.

The thermally conductive and thermally expandable sheet 4 is not limited to the configuration applied to one surface of the battery cell 3 shown in FIG. 1, and may be provided on two side surfaces of each battery cell 3 as shown in FIG. It may be provided on all four sides or all six sides.
As shown in FIG. 9, the heat conductive and heat expandable sheet 4 may be provided inside the battery module 1, particularly on the inner surface 1 of the housing 2.
As shown in FIG. 10, the heat conductive and heat expandable sheet 4 may be provided on the outside of the battery module 1, particularly on the outer surface 1 of the housing 2.
In FIG. 2, the heat conductive and heat expandable sheet 4 may be provided on the inner surface or the outer surface of the housing 11 constituting the battery pack 10, the space between the battery module 1 and the battery pack 10, and the like.

When the heat conductive heat expandable sheet 4 is heated by providing the heat conductive heat expandable sheet 4 at any of the above places, the heat conductive heat expandable sheet 4 acts as a heat insulating material, and fire and It blocks the space that serves as the heat flow path. The space serving as a flow path for fire and heat includes a space between the battery cell 3 and the battery cell 3, a space between the battery cell 3 and the housing 2 of the battery module 1, and the battery module 1 and the battery module 1. The space between them, the space between the battery module 1 and the housing 11 of the battery pack 10 and the like can be mentioned.

Next, a second embodiment of the present invention will be described with reference to FIGS. 11 and 12.

FIG. 11 is a schematic vertical sectional view of the battery module according to the second embodiment of the present invention.

In the housing 2 of the battery module 1 of the second embodiment, a plurality of battery cells 3 (three are shown in the figure) are housed side by side so as to be separated from each other and extend in the horizontal direction, and adjacent batteries are accommodated. A thermally conductive and thermally expandable sheet 4 is arranged between the cells 3. In the present embodiment, the battery cell 3 and the heat conductive heat expandable sheet 4 are alternately laminated substantially parallel to each other. In the figure, the battery cell 3 and the heat conductive and heat expandable sheet 4 adjacent to the battery cell 3 are in contact with each other, but they may be separated from each other. A space 5 is provided around the battery cell 3 and the heat conductive thermal expansion sheet 4 in the housing 2, and the space 5 acts as an air passage for heat dissipation of the battery cell 3. When the battery cell 3 is heated during operation, the battery cell 3 can be cooled faster by securing such a space 5.

When the heat conductive heat expandable sheet 4 is heated due to abnormal heat generation or fire, the heat conductive heat expandable sheet 4 expands, blocking the space serving as a flow path for fire and heat, and adjacent batteries. A heat insulating layer is formed between the cells 3. Therefore, heat transfer or ignition from one battery cell 3 to the adjacent battery cell 3 can be prevented, suppressed, or delayed, and the safety of the battery is ensured.

FIG. 12 is a schematic vertical sectional view of the battery pack 10 including the battery module 1 of FIG. A plurality of battery modules 1 (two are shown in the figure) are housed in the housing 11 of the battery pack 10. Further, a heat conductive and heat expandable sheet 4 is arranged between adjacent battery modules 1. A plurality of battery modules 1 are arranged in series or in parallel.

Examples of the method of installing and fixing the heat conductive heat expandable sheet 4 to the housing 11 forming the battery module 1 include the following methods: The heat conductive heat expandable sheet 4 is attached via an adhesive material. Alternatively, a method of sticking and fixing the heat conductive heat expandable sheet 4 by self-adhesiveness, a method of laminating the heat conductive heat expandable sheet 4 on the housing 2 forming the battery module 1 and then fixing it using a frame. And so on.

With such a configuration, even in the battery pack 10 of FIG. 12, the battery module 1 can exhibit heat insulating properties at a high temperature such as abnormal heat generation or fire while securing an air passage for heat dissipation of the battery cell 3.

Although the battery module of the second embodiment of the present invention has been described so far, the present invention is not limited to this, and various modifications based on the technical idea of the present invention are possible.
Another embodiment of the first embodiment described with reference to FIGS. 3 to 10 can also be applied to the second embodiment.

In the first and second embodiments described above, as an example of the heat conductive heat expandable molded body formed from the heat conductive heat expandable resin composition, the heat conductive body is a sheet-shaped molded body. Although the heat-expandable sheet 4 has been described, the form of the heat-conducting heat-expandable molded body is not limited to the sheet shape. For example, the heat conductive and heat-expandable molded body can be in any shape as appropriate, such as a film shape, a block shape, a cylindrical shape, a square shape, etc. It also includes the case where a part (for example, one side) of the molded product is missing, as in the case of having an opening. For example, FIG. 13 shows a substantially cylindrical heat conductive thermal expandable molded body 13 applied to a cylindrical battery cell 12, and FIG. 14 shows a substantially square heat applied to a square battery cell 14. It is a conductive heat-expandable molded body 15. The thermally conductive and thermally expandable molded bodies 13 and 15 are shaped according to the outer shape of the battery cells 12 and 14, and are shown in a state in which the battery cells 12 and 14 are housed, respectively.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

[Example 1]
The following components are kneaded with a kneading roll, the obtained heat conductive heat-expandable resin composition is applied onto a mold release paper, pressed at 80 ° C. for 3 hours to cure, and a 0.5 mm thick sheet-like example is used. The thermally conductive thermal expansion resin composition of 1 was obtained.
Bisphenol F type epoxy monomer ("jER807" manufactured by Mitsubishi Chemical Co., Ltd.) 60 parts by mass Diamine-based curing agent ("jER Cure FL052" manufactured by Mitsubishi Chemical Co., Ltd.) 40 parts by mass magnesium oxide ("RF-70C" manufactured by Ube Materials Co., Ltd. -SC ") 300 parts by mass Boron nitride ("Denka Boron Nitride FP40" manufactured by Denka Co., Ltd.) 55 parts by mass Thermally expandable microcapsules ("Advancel EMH204" manufactured by Sekisui Chemical Co., Ltd.) 20 parts by mass Thermally expandable graphite (GREP-EG manufactured by Suzuhiro Chemical Co., Ltd.) 20 parts by mass Ammonium polyphosphate ("FCP-770" manufactured by Suzuhiro Chemical Co., Ltd.) 30 parts by mass, and diisodecyl phthalate (manufactured by J-PLUS Co., Ltd.) 20 parts by mass

The thermal conductivity is measured using a steady-state thermal conductivity measuring device manufactured by RHESCA (measurement conditions: pressure 50 N, 80 ° C for 3 min), and the expansion start temperature is such that the hot plate is heated from room temperature to 30 ° C / min and expansion starts. Was visually measured. The expansion coefficient was calculated by heating the thermally conductive thermally expandable resin composition, quenching it, and measuring the thickness. The expansion rate is such that the heat conductive heat expandable resin composition is placed on a hot plate and the temperature is raised from room temperature to 200 ° C. at 30 ° C./min, and the heat conductive heat expandable resin composition starts to expand and then expands. It is a value measured by the time until the end.

Thermal conductivity before thermal expansion (25 ° C) The thermal conductivity of the thermally expandable resin composition is 3.0 W / m · K, the expansion start temperature is 115 ° C, and the expansion coefficient after expansion at 200 ° C is It was 10 times, the thermal conductivity was 0.2 W / m · K, and the expansion rate was 15 seconds.

[Example 2]
The following ingredients were kneaded with a kneading roll. The obtained heat-conducting heat-expandable resin composition was applied onto a release paper and irradiated with an acceleration voltage of 500 keV electron beam 2.5 Mrad to obtain a 0.5 mm-thick heat-conducting heat-expandable resin composition.
EPDM (“EP21” manufactured by JSR Co., Ltd.) / Liquid EPDM (“Trirene65” manufactured by Lion Elastomers) 50 parts by mass / 50 parts by mass Magnesium oxide (“RF-70C-SC” manufactured by Ube Materials Co., Ltd.) 250 parts by mass Boron nitride (Denka Co., Ltd. "Dencaboron Nitride FP40" 30 parts by mass Nanodiamond (Carbodeon "uDiamond ™ hydrogenP") 70 parts by mass Thermally expandable microcapsules (AkzoNobel "Expancel031-40") 30 parts by mass 100 parts by mass of thermally expandable graphite (GREP-EG manufactured by Suzuhiro Chemical Co., Ltd.) and 100 parts by mass of ammonium polyphosphate ("FCP-770" manufactured by Suzuhiro Chemical Co., Ltd.)

Thermal conductivity before thermal expansion (25 ° C) The thermal conductivity of the thermally expandable resin composition is 5.0 W / m · K, the expansion start temperature is 80 ° C, and the expansion coefficient after thermal expansion at 200 ° C. Was 40 times, the thermal conductivity was 0.1 W / m · K, and the expansion rate was 5 seconds.

[Example 3]
The following components were kneaded with a kneading roll to obtain a heat conductive heat-expandable resin composition having a thickness of 0.5 mm.
EVA (“LV430” manufactured by Nippon Polyethylene Co., Ltd.) 100 parts by mass Magnesium oxide (“RF-70C-SC” manufactured by Ube Materials Co., Ltd.) 200 parts by mass Boron nitride (“Dencaboron Nitride FP40” manufactured by Denka Co., Ltd.) 100 Alumina by mass (“AL” manufactured by Showa Denko Co., Ltd.) 50 parts by mass Thermally expandable microcapsule (“Advancel EML101” manufactured by Sekisui Chemical Co., Ltd.) 10 parts by mass Thermally expandable graphite (GREP by Suzuhiro Chemical Co., Ltd.) 20 parts by mass of EG) and 30 parts by mass of ammonium polyphosphate (“FCP-770” manufactured by Suzuhiro Chemical Co., Ltd.)

Thermal conductivity before thermal expansion (25 ° C) The thermal conductivity of the thermally expandable resin composition is 1.0 W / m · K, the expansion start temperature is 100 ° C, and the expansion coefficient after thermal expansion at 200 ° C. Was 5 times, the thermal conductivity was 0.5 W / m · K, and the expansion rate was 30 seconds.

[Test Example 1 LiB experiment]
Each heat conductive and heat expandable resin composition of Examples 1-3 before heating is attached to a lithium ion secondary battery as a battery cell (“NCR18650” manufactured by Panasonic Corporation, hereinafter also referred to as LiB) to conduct heat conduction. A surface heater was installed on the side opposite to LiB in the heat-expandable resin composition. The state of LiB was visually confirmed while heating the surface heater from 25 ° C. to 200 ° C. As a result, it was confirmed that there was no abnormality in LiB in both Examples 1-3. In other words, the safety of the battery was ensured even during heating.
In addition, each heat conductive thermal expansion resin composition of Example 1-3 (thermal conductivity, Example 1: 3.0 W / m · K, Example 2: 5.0 W / m · K, Example 3 : 1.0 W / m · K) is attached to the surface heater, and the surface temperature of the surface heater and the surface temperature of the thermally conductive heat-expandable resin composition during the temperature of the surface heater from 25 ° C. to less than 80 ° C. Was confirmed to be at the same temperature at the same time. It was confirmed that the heat conductive and heat expandable resin composition has high heat dissipation.

Although the embodiments and examples of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications based on the technical idea of the present invention are possible.
In addition, the present invention can also adopt the following configurations.

(1) It has a thermal conductivity of 1 W / m · K or more at -30 ° C to 80 ° C, starts expansion at a temperature exceeding 80 ° C, and has a thermal conductivity of 0.5 W / m · K or less after thermal expansion. A thermally conductive, thermally expandable resin composition.

(2) The thermally conductive thermally expandable resin composition according to (1), which contains a thermally conductive filler.
(3) The thermal conductivity according to (2), wherein the thermally conductive heat-expandable resin composition contains a resin component, and the content of the thermally conductive filler is 10 to 3500 parts by mass with respect to 100 parts by mass of the resin component. Thermally expandable resin composition.
(4) The heat conductive heat expandable resin composition according to (3), wherein the content of the heat conductive filler is 10 to 2000 parts by mass with respect to 100 parts by mass of the resin component.

(5) The thermally conductive thermally expandable resin composition according to any one of (1) to (4), which contains an expandable material.
(6) The heat conduction according to (5), wherein the expandable material is a heat-expandable microcapsule, a water-containing microcapsule, a foaming agent, a microencapsulated foaming agent, a heat-expandable layered inorganic substance, or a combination thereof. A heat-expandable resin composition.
(7) The heat conductive heat-expandable resin composition contains a resin component, and the content of the expandable material is 0.1 to 500 parts by mass with respect to 100 parts by mass of the resin component (5) or (6). The thermally conductive thermoexpandable resin composition according to.
(8) The thermally conductive thermally expandable resin composition according to (7), wherein the content of the expandable material is 1 to 400 parts by mass with respect to 100 parts by mass of the resin component.

(9) A heat-conducting heat-expandable molded product formed from the heat-conducting heat-expandable resin composition according to any one of (1) to (8).
(10) The heat-conducting heat-expandable molded body according to (9), which has a heat-dissipating portion on one surface.
(11) It has a thermal conductivity of 1 W / m · K or more at -30 ° C to 80 ° C, starts expansion at a temperature exceeding 80 ° C, and has a thermal conductivity of 0.5 W / m · K or less after thermal expansion. Thermally conductive and thermally expandable sheet.
(12) The thermally conductive thermally expandable sheet according to (11), which contains a thermally conductive filler.
(13) The thermal conductivity according to (12), wherein the thermally conductive heat-expandable resin composition contains a resin component, and the content of the thermally conductive filler is 10 to 3500 parts by mass with respect to 100 parts by mass of the resin component. Sexually heat-expandable sheet.
(14) The heat conductive heat expandable sheet according to (13), wherein the content of the heat conductive filler is 10 to 2000 parts by mass with respect to 100 parts by mass of the resin component with respect to 100 parts by mass of the resin component.
(15) The thermally conductive thermally expandable sheet according to any one of (11) to (14), which contains an expandable material.
(16) The heat conduction according to (15), wherein the expandable material is a heat-expandable microcapsule, a water-containing microcapsule, a foaming agent, a microencapsulated foaming agent, a heat-expandable layered inorganic substance, or a combination thereof. Sexually expansive sheet.
(17) The thermally conductive thermally expandable resin composition contains a resin component, and the content of the expandable material is 0.1 to 500 parts by mass with respect to 100 parts by mass of the resin component (15) or (16). ). The heat conductive and heat expandable sheet.
(18) The thermally conductive thermally expandable sheet according to (17), wherein the content of the expandable material is 1 to 400 parts by mass with respect to 100 parts by mass of the resin component.
(19) The heat conductive and heat expandable sheet according to any one of (11) to (18), which has a heat radiating portion on one surface.
(20) A battery module including a plurality of battery cells and a housing for accommodating the plurality of battery cells.
A layer made of the heat conductive heat expandable resin composition according to any one of (1) to (8) on the surface of the battery cell, and the heat conductive heat expansion according to (9) or (10). A battery module in which a sex-molded body or a heat-conducting heat-expandable sheet according to (11) to (19) is arranged.

(21) A battery module including a plurality of battery cells and a housing for accommodating the plurality of battery cells, and a surface having the heat radiating portion on the surface of the battery cell is the surface of the battery cell. The layer made of the heat-conducting heat-expandable resin composition according to any one of (1) to (8) so as to be on the side opposite to the sticking surface, and the heat-conducting heat according to (9) or (10). The expandable molded body or the thermally conductive thermally expandable sheet according to any one of (11) to (19) is arranged, and a space is provided between adjacent battery cells to enable air flow. Battery module.

(22) A battery module including a plurality of battery cells and a housing for accommodating the plurality of battery cells, wherein any of (1) to (8) is provided on the inner surface, the outer surface, or both of the housings. The layer made of the heat-conducting heat-expandable resin composition according to (9) or (10), or the heat-conducting heat-expandable molded body according to any one of (11) to (19). A battery module in which a thermally conductive and thermally expandable sheet is arranged.

(23) The plurality of battery modules according to any one of (20) to (22), an electrical connection cable electrically connected to each of the plurality of battery modules, the plurality of battery modules, and the electrical connection. A battery pack including a housing for accommodating cables, wherein a layer made of the heat conductive heat expandable resin composition or the heat conductive heat expandable molded body is between the battery cells. Space, space between the battery cell and the housing of the battery module, space inside the housing of the battery module, space between the battery module and the battery module, space between the battery module and the housing of the battery pack, and A battery pack installed in one or more places in the space inside the battery pack housing.

Claims (11)

It contains a thermally conductive filler, has a thermal conductivity of 1 W / m · K or more at -30 ° C to 80 ° C, starts expansion at a temperature exceeding 80 ° C, and has a thermal conductivity of 0.5 W after thermal expansion. A thermally conductive and thermally expandable resin composition for a battery having a temperature of / m · K or less. The thermally conductive thermally expandable resin composition according to claim 1 , which contains an expandable material. A heat-conducting heat-expandable molded product formed from the heat-conducting heat-expandable resin composition according to claim 1 or 2. The heat conductive and heat expandable molded product according to claim 3 , which has a heat radiating portion on one surface. It contains a thermally conductive filler, has a thermal conductivity of 1 W / m · K or more at -30 ° C to 80 ° C, starts expansion at a temperature exceeding 80 ° C, and has a thermal conductivity of 0.5 W after thermal expansion. Thermally conductive and thermally expandable sheet for batteries with a temperature of / mK or less. The thermally conductive thermally expandable sheet according to claim 5 , wherein the expansion rate is 60 seconds or less. A coating material containing the thermally conductive and thermally expandable resin composition according to claim 1 or 2. A battery module including a plurality of battery cells and a housing for accommodating the plurality of battery cells.
On the surface of the battery cell, a layer of a thermally conductive heat-expandable resin composition according to claim 1 or 2, thermally conductive heat-expandable molded body according to claim 3 or 4, or claim 5 or A battery module in which the heat conductive and heat expandable sheet according to No. 6 is arranged. A battery module including a plurality of battery cells and a housing for accommodating the plurality of battery cells, and a surface having the heat radiating portion on the surface of the battery cell is a surface to be attached to the surface of the battery cell. The layer made of the heat conductive heat expandable resin composition according to claim 1 or 2 , the heat conductive heat expandable molded body according to claim 3 or 4 , or claim 5 or A battery module in which the heat conductive and heat expandable sheet according to No. 6 is arranged, and a space is provided between adjacent battery cells to enable air flow. The heat conductive heat according to claim 1 or 2 , wherein the battery module includes a plurality of battery cells and a housing for accommodating the plurality of battery cells, and the inner surface, the outer surface, or both of the housings. A battery module in which a layer made of an expandable resin composition, the heat conductive heat expandable molded product according to claim 3 or 4 , or the heat conductive heat expandable sheet according to claim 5 or 6 is arranged. A housing for accommodating the battery module according to any one of claims 8 to 10 , an electric connection cable electrically connected to each of the plurality of battery modules, the plurality of battery modules, and the electric connection cable. A battery pack including a body, wherein the layer made of the heat conductive heat expandable resin composition or the heat conductive heat expandable molded body is a space between a battery cell and a battery cell, and a battery cell. The space between the battery module housing, the space inside the battery module housing, the space between the battery module and the battery module, the space between the battery module and the battery pack housing, and the battery pack housing. Battery packs installed in one or more of the internal spaces.

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