JP2018116805A - Secondary battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery module with a light weight and an excellent heat dissipation, capable of easily assembling.SOLUTION: A secondary battery module 1 comprises: a housing 2 constructed by a resin molding; a plurality of battery cells 10 housed in the hosing 2; a plurality of partition parts 12 that is housed in the housing 2 and separates the plurality of battery cells 10; a plurality of thermal conductivity foaming bodies 14 that is housed in the housing 2, and is arranged in a state of being contacted with a member between each battery cell 10 and each battery cell 12; and a thermal expansion fireproof material 16 attached to an inner surface of the housing 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a secondary battery module.

  Lithium ion batteries have been used in small electronic devices such as personal computers and mobile phones because of their high output density. In recent years, it has begun to be used in HEVs (hybrid vehicles) and EVs (electric vehicles), and further, attempts are being made to install it on heavy machinery such as construction machines with high output. Further, it is expected to be used as a storage battery for power leveling of power generation facilities with unstable output such as solar power generation and wind power generation. When used in these applications, the battery pack is assembled in a power supply system as a battery pack in which a plurality of single cells (battery cells) are combined, that is, a battery module.

  If more battery cells are used in order to increase the output of the lithium ion battery, heat generated by the operation of the battery cells tends to be trapped inside the battery.

  In order to efficiently release the heat inside the battery to the outside, Patent Document 1 discloses a lithium ion battery module provided with a heat radiating member containing metal or ceramics.

JP2012-138315

  However, since the heat dissipating member of Patent Document 1 is made of metal or ceramics, the lithium ion battery module is heavy. Further, the heat dissipating member of Patent Document 1 has a frame-shaped structure that surrounds the four sides of the electrode stack, and it is necessary to fit each of the batteries one by one, and the assembly of the lithium ion battery module is complicated.

  An object of the present invention is to provide a secondary battery module that is lightweight, easier to assemble, and excellent in heat dissipation.

  In order to achieve the above object, the present inventors have found that the above-mentioned problems can be solved by providing a partition portion made of a thermally conductive resin molded body in the casing, and have completed the present invention. It was. According to the present invention, the following configuration is provided.

Item 1. A housing composed of a molded body of resin having thermal conductivity;
A plurality of battery cells housed in the housing;
A partition part provided in the housing and partitioning the plurality of battery cells;
With
A secondary battery module, wherein the partition portion is made of a resin having thermal conductivity, and is provided in contact with a part of the housing.

  Item 2. Item 2. The secondary battery module according to Item 1, wherein the plurality of partition portions are integrally formed with the housing.

  Item 3. Item 2. The item according to Item 1 or 2, wherein one end of each partition portion is connected to one of the two wall portions, and a plurality of holes are formed in the wall portion to which one end of the partition portion is connected. Next battery module.

  Item 4. Item 4. The secondary battery according to any one of Items 1 to 3, further comprising a thermally conductive foam that is housed in the housing and disposed between the battery cell and the partition portion in contact with these members. module.

  Item 5. Item 5. The secondary battery module according to any one of Items 1 to 4, further comprising a thermally conductive foam housed in the housing and disposed between the battery cell and the housing.

  Item 6. Item 6. The secondary battery module according to any one of Items 1 to 5, further comprising a thermally expandable refractory material attached to the inner surface of the housing.

Item 7. The partition is provided to extend between two wall portions of the housing facing each other;
A thermally conductive foam is disposed on the inner surface side of at least one of the two walls,
The secondary battery module according to claim 6, wherein the thermally expandable refractory material is attached to an inner surface of two side wall portions facing each other in the housing different from the two wall portions.

  Item 8. Item 8. The secondary battery module according to any one of Items 1 to 7, wherein the casing is sputtered.

Item 9. The housing includes a thermoplastic resin and graphite particles;
The graphite particles have a volume average particle diameter of 0.1 μm or more and less than 40 μm,
Content of the graphite particles with respect to 100 parts by weight of the thermoplastic resin is 10 parts by weight or more and 200 parts by weight or less,
In the main wall portion of the housing, when an arbitrary direction is an x direction and a direction orthogonal to the x direction is a y direction, and a thickness direction of the housing is a z direction,
Item 8. The thermal conductivity λx in the x direction, the thermal conductivity λy in the y direction, and the thermal conductivity λz in the z direction satisfy min (λx, λy) / λz ≧ 3. The secondary battery module as described in.

  According to the present invention, it is possible to effectively dissipate heat generated inside the secondary battery module with a lightweight and easy-to-assemble configuration.

1 is a partially broken perspective view of a lithium ion battery according to a first embodiment of the present invention. FIG. The longitudinal cross-sectional view of the lithium ion battery in the 2-2 line of FIG. The perspective view which looked at the lithium ion battery of FIG. 1 from the side surface on the opposite side.

  In this specification, “battery” means 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, It means secondary batteries such as lead-acid batteries and air batteries.

  In this specification, the “battery cell” refers to a structural unit of a laminated battery in which a positive electrode material, a negative electrode material, a separator, a positive electrode tab, a negative electrode tab, and the like are accommodated in an exterior film. Examples of the exterior film include an aluminum film on which a polyethylene terephthalate film is laminated.

  In this specification, the “secondary battery module” refers to a structural unit of a battery in which a plurality of secondary batteries are housed in a casing.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. For convenience, the vertical direction in the figure is “upper” and “lower”, and the horizontal direction is “left” and “right”.
[Secondary battery module]
As shown in FIG. 1 and FIG. 2, the lithium ion battery module 1 of the first embodiment as a secondary battery module is housed in a housing 2 composed of a molded body of heat conductive resin, and the housing 2. The plurality of battery cells 10, the plurality of partition portions 12 provided in the housing 2 and partitioning the plurality of battery cells 10, and housed in the housing 2, and between the battery cells 10 and the partition portion 12. A plurality of thermally conductive foams 14 arranged in contact with the members 10 and 12, and the inner surfaces of the two wall portions 5 and 6 facing each other of the casing 2 perpendicular to the lower side wall portion 3 and the upper side wall portion 4. And a thermally expandable refractory material 16 attached thereto. In the present embodiment, the partition portion 12 is a plurality of partition portions 12 that extend in a substantially vertical direction with respect to the lower wall portion 3 and the upper wall portion 4 between the lower wall portion 3 and the upper wall portion 4 facing each other of the housing 2. Yes, it is composed of a resin molded body. The thickness of the heat-expandable refractory material 16 is usually about 0.1 to 2 mm. The lower side wall part 3 constitutes a first wall part, and the upper side wall part 4 constitutes a second wall part. The thermally expandable refractory material 16 can be attached to the inner surfaces of the walls 5 and 6 by known adhesive means (not shown) such as an adhesive, an adhesive tape, and an adhesive sheet. Here, an acrylic adhesive is used. A flame retardant adhesive tape 17 with a layer is used. As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive is well known. As an adhesive tape or an adhesive sheet, for example, an adhesive tape or an adhesive sheet in which an acrylic adhesive layer is laminated, or an adhesive tape in which an acrylic adhesive layer is laminated on one side or both sides of a substrate such as a nonwoven fabric, or An adhesive sheet is mentioned.

  Although the dimension of the lithium ion battery module 1 is not specifically limited, For example, they are width 100-1000mm, depth 100-500mm, and height 50-300mm grade. In addition, the housing | casing 2 is comprised from the upper side wall part 4, the four side wall parts 5-8, and the lower side wall part 3, and as shown in FIG. ) Is provided with an opening 8a, and the battery cell 10 can be replaced and the elements inside the housing 2 can be maintained through the opening 8a. Usually, the opening 8 a is closed by covering the cover plate 9.

  In this embodiment, the heat conductive foam 14 is attached to both surfaces of the wide heat dissipation surface of each battery cell 10. The heat conductive foam 14 is a substantially rectangular sheet having a shape that fits the battery cell 10, and the heat conductive foam 14 is attached to the battery cell 10 by using known adhesive means such as an adhesive, an adhesive tape, and an adhesive sheet. (Not shown). The thickness of the thermally conductive foam 14 is usually 0.05 to 2 mm, preferably about 0.1 to 1 mm. As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive is well known. As an adhesive tape or an adhesive sheet, for example, an adhesive tape or an adhesive sheet in which an acrylic adhesive layer is laminated, or an adhesive tape in which an acrylic adhesive layer is laminated on one side or both sides of a substrate such as a nonwoven fabric, or An adhesive sheet is mentioned. The thickness of the pressure-sensitive adhesive tape or adhesive sheet is usually about 0.1 to 2 mm. The adhesive tape or the adhesive sheet may further have fire resistance. The battery cell 10 to which the thermally conductive foam 14 is attached is attached to the partition portion 12 on the surface opposite to the side to which the battery cell 10 is attached in the thermally conductive foam 14. The heat conductive foam 14 can be attached to the partition portion 12 by a known adhesive means (not shown) such as an adhesive, an adhesive tape, and an adhesive sheet. The adhesive tape or adhesive sheet used for attaching the thermally conductive foam 14 is preferably the thermally conductive foam 14 having excellent adhesion to the thermally conductive foam 14.

  The plurality of partition portions 12 are integrally formed with the lower side wall portion 3 of the housing 2 and the same thermally conductive resin composition. Each partition portion 12 includes a flat plate portion 12a (see FIG. 2) having a linear cross section and both end portions 12b and c extending substantially perpendicularly from the flat plate portion 12a, and the lower end portion 12b is continuous with the housing 2. However, the upper end of the upper end portion 12 c is separated from the upper side wall portion 4. In this embodiment, the battery cell 10 is attached to both surfaces of the flat plate part 12a of each partition part 12 via the heat conductive foam 14. A thermally conductive foam 14 is also attached between two battery cells 10 between adjacent partition portions 12. Since the contact area with respect to the lower side wall part 3 and the upper side wall part 4 is expanded at both end parts 12b and c, each partition part 12 has more battery cells 10 and thermal conductive foams 14 attached to the partition part 12. Support stably.

  Between the upper side wall part 4 and the upper end part 12c of the partition part 12, the heat conductive foam 18 comprised from the same material as the heat conductive foam 14 is arrange | positioned. Further, a thermally conductive foam 20 made of the same material as the thermally conductive foam 14 is disposed between the adjacent lower end portions 12 b and on the lower side wall portion 3. The heat conductive foam 18 is attached to the upper side wall portion 4 and the heat conductive foam 20 is attached to the lower side wall portion 3 by known adhesive means (not shown) such as an adhesive, an adhesive tape, and an adhesive sheet. Can be attached. As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive is well known. Examples of the pressure-sensitive adhesive include an adhesive tape or adhesive sheet in which an acrylic pressure-sensitive adhesive layer is laminated, or an adhesive tape or adhesive sheet in which an acrylic pressure-sensitive adhesive layer is laminated on one side or both sides of a substrate such as a nonwoven fabric. Can be mentioned.

  By providing the thermally conductive foam 18 and the thermally conductive foam 20, it is possible to improve both heat dissipation and buffering properties between the battery cell 10 and the housing 2.

  A plurality of ribs 4 a extending substantially in parallel along the short side direction of the housing 2 are provided on the upper side wall portion 4 of the housing 2. The plurality of ribs 4 a function to enhance the heat dissipation of the heat generated inside the housing 2 by expanding the surface area of the housing 2. The lower wall portion 4 of the housing 3 is provided with a plurality of holes 3 a having a substantially rectangular cross section formed so as to penetrate in the short side direction of the lower wall portion 4. The hole 3a also functions to cool the heat generated in the housing 2 and to improve heat dissipation. The wall 5 and the wall 6 are also provided with a plurality of ribs 5a and ribs 6a extending substantially in parallel.

  When the battery cell 10 generates heat by the operation, the heat generated from the battery cell 10 is transmitted to the thermally conductive foam 14 and the partition portion 12 attached to the battery cell 10, and from the flat plate portion 12 a of the partition portion 12. Furthermore, it is transmitted to both ends 12b and c of the partition part 12 in the up-down direction. The heat transmitted to the upper end portion 12 c of the partition portion 12 is transmitted to the upper side wall portion 4 through the heat conductive foam 18 and is released to the outside of the housing 2. The heat transmitted to the lower end portion 12b of the partition portion 12 is transmitted to the lower side wall portion 3, and partly reaches the lower end or side surface of the lower side wall portion 3 through the hole 3a, and the outside of the housing 2 Is released.

  Further, the battery cells 10 at both ends in the longitudinal direction of the casing 2 (left and right direction in FIG. 2) are further connected to a thermally expandable refractory material 16 via a thermally conductive foam 14. The thermally expandable refractory material 16 functions as a heat insulating layer that expands due to heat such as a fire. For example, when ignited in the housing 2, the thermally expandable refractory material 16 is adjacent to the housing 2 or another housing 2. It is possible to prevent the device from catching fire. Further, the heat-expandable refractory material 16 prevents heating from the adjacent casing 2 due to a fire or the like. The heat-expandable refractory material 16 is provided substantially in parallel with the extending direction of the partition portion 12 and is not provided at both end portions 12 b and 12 c of the partition portion 12, and thus does not hinder the release of heat generated from the battery cell 10.

  With the configuration described above, the lithium ion battery module 1 of the first embodiment is a lightweight and easy to assemble configuration, and can effectively dissipate heat generated inside the secondary battery module.

Here, the detail of each component of the lithium ion battery module 1 is demonstrated.
[Case]
First, the housing 2 will be described. Although the housing | casing 2 may be comprised from arbitrary resin materials, Preferably, in order to have the outstanding heat dissipation, it contains the thermoplastic resin as a matrix component, and a graphite particle. Graphite particles impart thermal conductivity. More preferably, the casing includes a thermoplastic resin and graphite particles, and the volume average particle diameter of the graphite particles is 0.1 μm or more and less than 40 μm, and the content of the graphite particles with respect to 100 parts by weight of the thermoplastic resin. 10 parts by weight or more and 200 parts by weight or less, and in the main wall part of the casing 2, that is, the upper side wall part 4, an arbitrary direction is defined as an x direction and a direction orthogonal to the x direction is defined as a y direction. When the z direction is the thickness direction (vertical direction in FIG. 2), the thermal conductivity λx in the x direction, the thermal conductivity λy in the y direction, and the thermal conductivity λz in the z direction are min (λx, λy) / λz ≧ 3 is satisfied. Since such a housing | casing 2 contains the graphite particle which has an average particle diameter in a specific range by a specific ratio, it is excellent in both heat dissipation and impact resistance. In addition, a main wall part points out the surface with the largest area among several surfaces in the outer surface of a housing | casing.

  The reason for this can be explained as follows. When an impact is applied to the housing 2, the interfacial separation occurs between the graphite particles and the resin, and the housing 2 is destroyed. Here, even when minute interfacial peeling occurs, it is considered that peeling is accelerated up to one graphite particle, but if the area of one graphite particle is small, the peeling area can be reduced. In addition, regarding the content, if the content of the graphite particles is small, the area of the interface between the graphite particles and the resin, which becomes the starting point of fracture, can be reduced. In the present invention, since the graphite particles having an average particle diameter of less than the above upper limit are contained in a content not more than the above upper limit, impact resistance is enhanced.

  Moreover, since this housing | casing 2 contains the graphite particle whose average particle diameter is more than the said minimum with content with more than the said minimum, it is excellent in heat dissipation.

  In particular, the housing 2 has a thermal conductivity λx in the x direction, a thermal conductivity λy in the y direction, and a thermal conductivity λz in the z direction satisfying min (λx, λy) / λz ≧ 3.

  The thermal conductivity in each of the x direction, the y direction, and the z direction can be calculated using the following equation (1).

Thermal conductivity (W / (m · K)) = thermal diffusivity × specific gravity × specific heat (1)
In Formula (1), the thermal diffusivity in each of the x direction, the y direction, and the z direction can be measured using, for example, a product name: TA33 manufactured by Bethel.

  The min (λx, λy) means a value having a lower thermal conductivity among λx and λy. Accordingly, min (λx, λy) / λz ≧ 3 means that the ratio of the lower thermal conductivity of λx and λy to λz is 3 or more.

  Since the housing 2 has min (λx, λy) / λz ≧ 3, the thermal conductivity in the surface direction is higher than the thermal conductivity in the thickness direction. Therefore, the housing | casing 2 is excellent in the heat dissipation in a surface direction.

  The impact resistance can be evaluated by conducting a Charpy impact resistance test in a 23 ° C. environment using a notched test piece in accordance with JIS K 7111.

The housing 2 is preferably sputtered for electromagnetic compatibility (EMC). The surface of the housing 2 is usually sputtered with a metal film such as Cu, a metal alloy film such as a Cu alloy film, an ITO film, an oxide film such as SiO ₂ and TiO ₂ , a nitride film such as TiN, SiN and SiON. It is applied by forming a film. Moreover, you may stick the material which has electromagnetic wave shielding performance on the surface of the housing | casing 2 for electromagnetic compatibility (EMC). Examples of the material having electromagnetic wave shielding performance include an electromagnetic wave shielding material having a fiber substrate such as a nonwoven fabric or a woven fabric and a metal film formed on one or both surfaces of the fiber substrate.

The housing | casing 2 can be obtained by shape | molding the resin composition containing a thermoplastic resin and graphite particle | grains, for example by methods, such as press work, an extrusion process, an extrusion lamination process, or injection molding.
[Thermal conductive foam]
Next, the heat conductive foam 14 will be described. Although the heat conductive foam 14 may be comprised from the arbitrary materials which transmit the heat emitted from the electronic cell 10, it is preferable that the resin as a matrix component and a heat conductive material are included, for example, A thermally conductive foam having a 25% compressive strength of 200 kPa or less obtained by foaming a resin composition containing an elastomer and a thermally conductive filler described in JP2013-231166A, and described in WO2014 / 083890A1 A thermally conductive foam having a heat conductive filler content of 100 to 500 parts by mass and a 25% compressive strength of 200 kPa or less with respect to 100 parts by mass of the elastomer resin thus obtained can be used. A 25% compressive strength of 200 kPa or less is preferable in terms of the flexibility of the thermally conductive foam 14.

  As the elastomer forming the heat conductive foam 14, a thermoplastic elastomer is suitable, and a compound not containing a siloxane compound is preferable.

  Examples of the thermoplastic elastomer include ethylene-propylene-diene rubber (EPDM), liquid ethylene-propylene-diene rubber, ethylene-propylene rubber (EPM), liquid ethylene-propylene rubber, acrylonitrile butadiene rubber (NBR), liquid acrylonitrile butadiene rubber, natural Rubber (NR), liquid natural rubber, polybutadiene rubber (BR), liquid polybutadiene rubber, polyisoprene rubber (IR), liquid polyisoprene rubber, styrene-butadiene block copolymer (SBR), liquid styrene-butadiene block copolymer , Hydrogenated styrene-butadiene block copolymer (SEB), liquid hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer (SEBS), liquid Hydrogenated styrene-butadiene-styrene block copolymer, hydrogenated styrene-isoprene block copolymer (SEP), liquid hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-isoprene-styrene block copolymer (SEPS) And at least one selected from liquid hydrogenated styrene-isoprene-styrene block copolymers and the like.

  Among them, it is preferable to use acrylonitrile butadiene rubber (NBR) from the advantage that it is easily subjected to electron beam crosslinking or chemical crosslinking and does not require a monomer as a crosslinking accelerator. Nitrile rubber is preferable because it has a small compression set and is less likely to deteriorate in airtightness due to the passage of the period of use.

  Since the above-mentioned thermoplastic elastomer generally has a glass transition temperature of room temperature or lower (for example, 20 ° C. or lower), the flexibility and shape followability of the thermally conductive foam 14 can be improved. Thereby, the heat conductive foam 14 can be deformed so as to follow the shape of the battery cell 10 that generates heat, and the contact area with the battery cell 10 is increased. Therefore, the heat conduction efficiency of the housing 2 can be increased.

  Moreover, in this invention, it is not limited to the elastomer mentioned above as a matrix component, For example, a silicone resin, an acrylic resin, etc. can also be used.

  As a heat conductive foam using a silicone resin, for example, a heat conductive foam described in WO2016 / 052599 can be used.

  The acrylic resin is obtained by polymerizing a monomer containing acrylic acid and / or methacrylic acid ester (hereinafter also referred to as (meth) acrylate). The (meth) acrylate usually has an alkyl group having 12 or less carbon atoms, specifically, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n-amyl (meth) acrylate, n -Hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate Is mentioned. Moreover, acrylic acid, methacrylic acid, itaconic acid, vinyl acetate, hydroxyalkyl acrylate, acrylamide, methacrylamide, etc. can be used as another monomer polymerizable with the acrylate monomer. In addition, when giving adhesiveness to the acrylic resin heat radiating foam sheet of the present invention, such a monomer is used in an amount sufficient to give adhesiveness to the acrylic resin foam, for example. Although not necessarily limited, it is generally 30 parts by mass or less per 100 parts by mass of (meth) acrylate.

  The monomer constituting the acrylic resin can contain a slight amount of polyfunctional (meth) acrylate such as 1,6-hexanediol diacrylate. Among these, the acrylic resin (A) has a structural unit derived from an alkyl (meth) acrylate having a C 3-12 alkyl group, and the alkyl (meth) having the C 3-12 alkyl group. The acrylate-derived structural unit is preferably contained in the acrylic resin (A) in an amount of 70 to 100% by mass, more preferably 80 to 100% by mass, and particularly preferably 90 to 100% by mass.

  The thermally conductive filler is preferably an insulating material, and includes at least one selected from aluminum oxide, magnesium oxide, boron nitride, talc, and aluminum nitride. Among these, it is preferable to use aluminum oxide.

  In addition, carbonaceous materials such as graphite, graphene, carbon black, carbon fiber, carbon nanotube, and carbon nanohorn have high thermal conductivity and are useful as a thermally conductive filler.

  100-500 mass parts is preferable with respect to 100 mass parts of resin, 120-400 mass parts is preferable, and, as for content of the said heat conductive filler, 150-350 mass parts is more preferable. When the content of the heat conductive filler is within the above range, sufficient heat conductivity can be imparted to the heat conductive foam 14 while suppressing a decrease in flexibility.

  In the thermally conductive foam 14, various additive components can be contained as necessary within a range where the object of the present invention is not impaired.

  The kind of the 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, cell nucleating agents, crystal nucleating agents, plasticizers, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, anti-aging agents, and the above-described conductivity imparting. Examples include fillers excluding materials, reinforcing agents, flame retardants, flame retardant aids, antistatic agents, surfactants, vulcanizing agents, and surface treatment agents. The addition amount of the additive can be appropriately selected within a range that does not impair the formation of bubbles and the like, and the addition amount used for normal resin foaming and molding can be adopted. Such additives can be used alone or in combination of two or more.

  The thermal conductivity of the thermally conductive foam 14 is preferably 0.01 to 10 W / m · K, and more preferably 0.05 to 2 W / m · K. If the thermal conductivity of the thermally conductive foam 14 is within the above range, the heat inside the housing 2 can be efficiently radiated to the outside.

The thermally conductive foam 14 can be produced by a known chemical foaming method or physical foaming method, and the production method is not particularly limited. For details, refer to JP2013-231166A and WO2014 / 083890A1.
[Thermal expansion refractory material]
Next, the thermally expandable refractory material 16 will be described. The resin composition constituting the heat-expandable refractory material 16 contains a matrix resin and heat-expandable graphite.

  Examples of the matrix resin include thermoplastic resins, thermosetting resins, elastomers, rubber substances, and combinations thereof.

  Examples of the thermoplastic resin include polypropylene resins, polyethylene resins, poly (1-) butene resins, polyolefin resins such as polypentene resins, polyester resins such as polyethylene terephthalate, polystyrene resins, acrylonitrile-butadiene-styrene (ABS) resins, and ethylene. Examples thereof include synthetic resins such as vinyl acetate copolymer (EVA), polycarbonate resin, polyphenylene ether resin, (meth) acrylic resin, polyamide resin, polyvinyl chloride resin, novolac resin, polyurethane resin, and polyisobutylene.

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

Examples of elastomers include olefin-based elastomers, styrene-based elastomers, ester-based elastomers, amide-based elastomers, vinyl chloride-based elastomers, and combinations thereof. Rubber materials include natural rubber, isoprene rubber, butadiene rubber, 1, 2 -Polybutadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, chlorinated butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber (EPDM), chlorosulfonated polyethylene, acrylic rubber, epichlorohydrin rubber, polyvulcanized rubber, Examples thereof include rubber materials such as non-vulcanized rubber, silicon rubber, fluorine rubber, and urethane rubber.

  These synthetic resins and / or rubber substances can be used singly or in combination. Among these synthetic resins and / or rubber substances, ethylene vinyl acetate copolymer (EVA), polyolefin resin and the like are more preferable.

  Thermally expandable graphite is a conventionally known substance that expands when heated, and powders such as natural scaly graphite, pyrolytic graphite, and quiche graphite are mixed with inorganic acids such as concentrated sulfuric acid, nitric acid, selenic acid, concentrated nitric acid, perchloric acid, A graphite intercalation compound produced by treatment with a strong oxidant such as perchlorate, permanganate, dichromate, hydrogen peroxide, etc. is there.

  The thermally expandable graphite may optionally be neutralized. That is, the thermally expandable graphite obtained by acid treatment as described above is further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound, or the like. The heat-expandable graphite obtained by 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 heat-expandable graphite in the heat-expandable refractory material 16 of the present invention is not particularly limited, but is 15% by mass or more. More preferably, it is 15 mass% or more. When the content of the thermally expandable graphite is 15% by mass or more, expansion suitable for preventing the passage of fire can be obtained. The upper limit of the content of the thermally expandable graphite is not particularly limited, but is preferably 50% by mass or less from the viewpoint of mechanical strength.

  The particle size of the thermally expandable graphite is preferably 20 to 200 mesh. When the particle size is 200 mesh or smaller, the degree of expansion of the graphite is sufficient to obtain an expanded heat insulating layer, and when the particle size is 20 mesh or larger, the dispersibility when blended in the resin is good and the physical properties are It is good.

  The resin composition constituting the thermally expandable refractory material 16 of the present invention can further include an inorganic filler. When the expanded heat insulating layer is formed, the inorganic filler increases the heat capacity and suppresses heat transfer, and works as an aggregate to improve the strength of the expanded heat insulating layer. The inorganic filler is not particularly limited, and examples thereof include metal oxides such as alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, and ferrite; calcium hydroxide, magnesium hydroxide, Metal hydroxides such as aluminum hydroxide and hydrotalcite; Metal carbonates such as basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, strontium carbonate and barium carbonate; Inorganic phosphate as flame retardant; Calcium sulfate , Calcium salts such as gypsum fiber, calcium silicate; silica, diatomaceous earth, dosonite, barium sulfate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica-based balloon , Al nitride Ni, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon balloon, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, zinc stearate, calcium stearate, aluminum borate, sulfide Examples include molybdenum, silicon carbide, stainless steel fiber, zinc borate, various magnetic powders, slag fiber, fly ash, and dewatered sludge. These inorganic fillers can be used alone or in combination of two or more.

  The content of the inorganic filler in the thermally expandable refractory material 16 is not particularly limited, but is preferably 1 to 50% by weight.

  Moreover, it is preferable that the total content of the heat-expandable graphite and the inorganic filler in the heat-expandable refractory material 16 is 5 to 80% by weight. The amount is preferably 5% by weight or more from the viewpoint of satisfying the amount of residue after combustion and obtaining sufficient fire resistance, and is preferably 80% by weight or less from the viewpoint of maintaining mechanical properties.

  Further, the resin composition constituting the thermally expandable refractory material 16 of the present invention may further contain a phosphorus compound in addition to the above-described components in order to increase the strength of the expanded heat insulating layer and improve the fireproof performance. it can. The phosphorus compound is not particularly limited. For example, red phosphorus; various phosphate esters such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate; sodium phosphate, Examples thereof include metal phosphates such as potassium phosphate and magnesium phosphate; ammonium polyphosphate; compounds represented by the following chemical formula (1). Among these, red phosphorus, ammonium polyphosphate, and a compound represented by the following chemical formula (1) are preferable from the viewpoint of fireproof performance, and ammonium polyphosphate is more preferable in terms of performance, safety, cost, and the like.

In the chemical formula (1), R ¹ and R ³ are the same or different and each represents hydrogen, a linear or branched alkyl group having 1 to 16 carbon atoms, or an aryl group having 6 to 16 carbon atoms. R ² is a hydroxyl group, a linear or branched alkyl group having 1 to 16 carbon atoms, a linear or branched alkoxyl group having 1 to 16 carbon atoms, an aryl group having 6 to 16 carbon atoms, or carbon. The aryloxy group of Formula 6-16 is shown.

  As red phosphorus, commercially available red phosphorus can be used, but from the viewpoint of safety such as moisture resistance and not spontaneously igniting during kneading, a material in which the surface of red phosphorus particles is coated with a resin is preferably used. The ammonium polyphosphate is not particularly limited, and examples thereof include ammonium polyphosphate and melamine-modified ammonium polyphosphate. Ammonium polyphosphate is preferably used from the viewpoint of handleability and the like. Examples of commercially available products include “AP422” and “AP462” manufactured by Clariant, “FR CROS 484” and “FR CROS 487” manufactured by Budenheim Iberica.

  The compound represented by the chemical formula (1) is not particularly limited, and examples thereof include methylphosphonic acid, dimethyl methylphosphonate, diethyl methylphosphonate, ethylphosphonic acid, n-propylphosphonic acid, n-butylphosphonic acid, and 2-methylpropylphosphone. Acid, t-butylphosphonic acid, 2,3-dimethyl-butylphosphonic acid, octylphosphonic acid, phenylphosphonic acid, dioctylphenylphosphonate, dimethylphosphinic acid, methylethylphosphinic acid, methylpropylphosphinic acid, diethylphosphinic acid, dioctylphosphine Examples include acids, phenylphosphinic acid, diethylphenylphosphinic acid, diphenylphosphinic acid, bis (4-methoxyphenyl) phosphinic acid and the like. Among them, t-butylphosphonic acid is preferable in terms of high flame retardancy although it is expensive. The said phosphorus compound can use 1 type, or 2 or more types.

  The addition amount of the phosphorus compound is preferably 0 to 200% by mass in the thermally expandable refractory material 16, and more preferably 10 to 100% by mass.

  Furthermore, the resin composition constituting the thermally expandable refractory material 16 of the present invention can further contain a plasticizer.

If the said plasticizer is a plasticizer generally used when manufacturing a polyvinyl chloride resin molded object, it will not specifically limit. Specifically, for example, phthalate plasticizers such as di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), diisodecyl phthalate (DIDP),
Fatty acid ester plasticizers such as di-2-ethylhexyl adipate (DOA), diisobutyl adipate (DIBA), dibutyl adipate (DBA); Epoxidized ester plasticizers such as epoxidized soybean oil; Polyesters such as adipic acid esters and adipic acid polyesters Examples include plasticizers; trimellitic acid ester plasticizers such as tri-2-ethylhexyl trimellitate (TOTM) and triisononyl trimellitate (TINTM); and process oils such as mineral oil. One or more plasticizers can be used.

  When the content of the plasticizer is small, the extrusion moldability tends to decrease, and when the content is large, the obtained molded product tends to be too soft. For this reason, although content of a plasticizer is not limited, It is preferable that it is 0-40 mass% in the thermally expansible refractory material 16, and it is more preferable that it is 5-35 mass%.

  Examples of the above-mentioned other components that can be contained in the heat-expandable refractory material 16 of the present invention are as long as the physical properties thereof are not impaired, and further, phenol-based, amine-based, sulfur-based antioxidants, metal damage, etc. Examples thereof include an inhibitor, an antistatic agent, a stabilizer, a crosslinking agent, a lubricant, a softener, and a pigment.

Further, the heat-expandable refractory material 16 is not particularly limited as long as it is thermally insulated by the expanded layer when exposed to a high temperature such as a fire and has the strength of the expanded layer. It is preferable that the expansion ratio after heating for 30 minutes under a heating condition of 50 kW / m ² is 3 to 50 times. If the expansion ratio is 3 times or more, the expansion ratio can sufficiently fill the burned-out portion of the matrix component, and if it is 50 times or less, the strength of the expansion layer is maintained and the effect of preventing the penetration of the flame is obtained. Kept. The expansion ratio is calculated as (the thickness of the test piece after heating) / (the thickness of the test piece before heating) of the test piece of the thermally expandable refractory material 16.

  The heat-expandable refractory material 16 comprises the above-mentioned matrix component, heat-expandable graphite, and optional other components, a single screw extruder, a twin screw extruder, an injection molding machine, a Banbury mixer, a kneader mixer, a kneading roll, a laika. It can manufacture by coating or shape | molding the refractory resin composition mixed using well-known apparatuses, such as a machine and a planetary stirrer. Molding includes press molding, extrusion molding, and injection molding. Coating or molding is well known in the art.

  So far, the present invention has been described by taking the first embodiment as an example. However, the present invention is not limited to this, and various modifications as described below are possible.

  In the first embodiment, the upper end of the upper end portion 12 c of the partition portion 12 is separated from the upper wall portion 4, but the upper end of the upper end portion 12 c may be in contact with the upper wall portion 4. Furthermore, the upper end portion 12c, the flat plate portion 12a, and the lower end portion 12b of the partition portion 12 may be continuously formed integrally with the housing 2.

  In 1st Embodiment, although the battery cell 10 is attached via the heat conductive foam 14 on both surfaces of the flat plate part 12a of each partition part 12 of the partition part 12, the flat plate of each partition part 12 of the partition part 12 is shown. The battery cell 10 may be attached only to one side of the portion 12a.

  In 1st Embodiment, although the partition part 12 is integrally molded with the lower wall part 3, the partition part 12 and the lower wall part 3 are comprised from another member, and the partition part 12 is made with respect to the lower member 3, You may join by well-known adhesion means, such as mechanical coupling | bonding, heat welding, an adhesive, an adhesive tape, and an adhesive sheet.

  In the first embodiment, the heat conductive foam 14 is attached between the two battery cells 10 between the adjacent partition portions 12, but the heat conductive member has a composition different from that of the heat conductive foam 14. May be provided, and the two battery cells 10 may be provided with a space therebetween.

  The housing 2 may not have the opening 8a on the side wall, and may have a configuration in which a lid portion including the upper side wall portion 4 and the four side walls is detachably fixed to the lower side wall portion 3. .

  The heat-expandable refractory material 16 may be further arranged in a space between the battery cell 2 and the heat conductive foam 18 or a space between the battery cell 2 and the heat conductive foam 20.

  The surface of the upper wall portion 4 may be a curved surface instead of a flat surface.

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

  A lithium ion battery module was manufactured using the following components.

  The casing of the lithium ion battery module was composed of a resin molded body having a width of 500 mm × depth of 300 mm × height of 150 mm. The partition part was formed integrally with the housing. The heat-expandable refractory material was used by cutting a sheet-like roll product having a width of 1000 mm and a length of 1 m (thickness of 0.3 mm). The thermally conductive foam was used by cutting a sheet-like roll product having a width of 410 mm × a length of 5 m (thickness of 0.5 mm). The pressure-sensitive adhesive sheet for fixing the heat-expandable refractory material was used by cutting a pressure-sensitive adhesive sheet containing an A4 size (0.7 mm thick) acrylic pressure-sensitive adhesive. As the pressure-sensitive adhesive sheet for fixing the heat conductive foam, a pressure-sensitive adhesive sheet containing an acrylic pressure-sensitive adhesive having an A4 size or width of 300 or 400 mm × length of 50 m (thickness of 0.13 mm) was used.

  Using the adhesive sheet for fixing a heat conductive foam, the heat conductive foam was affixed to the commercially available battery cell, and this was further attached to the partition part. The heat-expandable refractory material was attached to the housing using an adhesive sheet for fixing the heat-expandable refractory material.

  DESCRIPTION OF SYMBOLS 1 ... Lithium ion battery module as a secondary battery module, 2 ... Housing | casing, 3, 4 ... Two wall part, 3a ... Hole, 5, 6 ... Two wall parts which face each other different from two wall parts, DESCRIPTION OF SYMBOLS 10 ... Battery cell, 12 ... Partition part, 12b, c ... End part of partition part, 14 ... Thermally conductive foam, 16 ... Thermal expansion fireproof material.

Claims (9)

A housing composed of a molded body of resin having thermal conductivity;
A plurality of battery cells housed in the housing;
A partition part provided in the housing and partitioning the plurality of battery cells;
With
A secondary battery module, wherein the partition portion is made of a resin having thermal conductivity, and is provided in contact with a part of the housing.   The secondary battery module according to claim 1, wherein the plurality of partition portions are integrally formed with the housing.   The one end of each partition part is connected to one of the two wall parts, and a plurality of holes are formed in the wall part to which one end of the partition part is connected. Secondary battery module.   The secondary in any one of Claims 1-3 provided with the heat conductive foam accommodated in the said housing | casing and arrange | positioned in the state which contacted these members between the said battery cell and the said partition part. Battery module.   The secondary battery module according to claim 1, further comprising a thermally conductive foam housed in the housing and disposed between the battery cell and the housing.   The secondary battery module according to claim 1, comprising a thermally expandable refractory material attached to the inner surface of the housing. The partition is provided to extend between two wall portions of the housing facing each other;
A thermally conductive foam is disposed on the inner surface side of at least one of the two walls,
The secondary battery module according to claim 6, wherein the thermally expandable refractory material is attached to an inner surface of two side wall portions facing each other in the casing, which are different from the two wall portions.   The secondary battery module according to claim 1, wherein the casing is sputtered. The housing includes a thermoplastic resin and graphite particles;
The graphite particles have a volume average particle diameter of 0.1 μm or more and less than 40 μm,
Content of the graphite particles with respect to 100 parts by weight of the thermoplastic resin is 10 parts by weight or more and 200 parts by weight or less,
In the main wall portion of the housing, when an arbitrary direction is an x direction and a direction orthogonal to the x direction is a y direction, and a thickness direction of the housing is a z direction,
The thermal conductivity λx in the x direction, the thermal conductivity λy in the y direction, and the thermal conductivity λz in the z direction satisfy min (λx, λy) / λz ≧ 3. A secondary battery module according to claim 1.