KR102425374B1 - Silicone pad for preventing thermal runaway function having thermal diffusion sheet, and battery pack with the same - Google Patents

Abstract

The present invention relates to a silicone pad for battery thermal runaway delay including a heat diffusion sheet and a battery pack comprising the same. The purpose of the present invention is to provide a silicone pad for battery thermal runaway delay including a heat diffusion sheet and a battery pack comprising the same, in which thermal runaway occurring in battery cells can be delayed and/or prevented by a silicone pad in which a silicone foam containing a flame retardant filler and a platinum-based flame retardant is integrally installed on one surface or both surfaces of a heat diffusion sheet. According to the present invention, the silicone foam is integrally provided on one surface or both surfaces of a heat diffusion sheet, wherein the silicone foam has a foam structure having a hardness (Shore OO) of 10 to 60 and a density of 0.20 to 0.45 (ｇ/cm^3). In the heat diffusion sheet, a silicone pad for thermal runaway delay, which is composed of a heat-conductive metal-based sheet or a heat-conductive carbon-based sheet, is installed between battery cells as a buffer pad to delay or prevent the spread of heat generated in one battery cell to another battery cell.

Description

A silicone pad for delaying thermal runaway of a battery having a thermal diffusion sheet and a battery pack comprising the same

The present invention relates to a silicon pad for delaying thermal runaway of a battery having a thermal diffusion sheet and a battery pack including the same, wherein a silicon pad having a multilayer structure in which a silicon foam and a thermal diffusion sheet are integrated is installed between the battery cells, It relates to a silicon pad for delaying thermal runaway of a battery having a thermal diffusion sheet capable of preventing thermal runaway phenomenon by blocking thermal diffusion due to a rise in temperature of a battery cell while having a cushioning function according to surface pressure, and a battery pack including the same .

An eco-friendly vehicle means an electric vehicle, a fuel cell vehicle, etc. that do not emit exhaust gas, and the eco-friendly vehicle includes a motor for driving and a battery for driving the same.

As described above, in a battery pack applied to an eco-friendly vehicle, a plurality of battery cells are stacked in a case, and a buffer pad made of a stretchable foam member according to pressure (surface pressure) is disposed between the battery cells.

The battery pack made as described above is continuously heated due to manufacturing defects, mishandling or misuse of batteries, short circuits in some battery cells, etc. If it exceeds , thermal runaway occurs.

In addition, since a plurality of the battery cells are closely stacked, when a thermal runaway phenomenon occurs in some battery cells, the thermal runaway phenomenon propagates to adjacent battery cells within a short period of time, so that the battery unit having a larger capacity than the battery cell. There is a problem that can lead to disasters such as ignition or explosion of the module or battery pack.

In particular, when a thermal runaway phenomenon occurs, the battery cell generates a high temperature region of about 600° C. to 800° C., so that the surrounding combustibles are ignited due to such a high temperature, thereby further increasing the risk of ignition.

The conventionally used battery pack for an electric vehicle is the heat generated in one battery cell by the installation of a buffer pad made of urethane foam (PU foam) between one battery cell and another adjacent battery cell. In order to prevent the runaway phenomenon from propagating to another battery cell, that is, the thermal runaway propagation phenomenon is delayed/prevented.

However, the urethane foam (PU foam) has a cushioning function that can be stretched and contracted according to pressure (surface pressure), but has poor heat resistance and poor flame retardancy, so when the temperature of the battery rises, thermal runaway There was a problem that the foam was decomposed in a lower temperature region (near 200 ° C.) than the high temperature region in which the phenomenon occurred, and the required thermal runaway delay effect could not be expected.

Laid-open Patent Publication No. 10-2020-0106378 (2020.09.14) Registered Patent Publication No. 10-1518189 (2015.04.29) Laid-Open Patent Publication No. 10-2020-0141570 (2020.12.21) Registered Patent Publication No. 10-2058194 (2019.12.16)

An object of the present invention is to provide a thermal diffusion sheet in which thermal runaway of a battery cell can be delayed/prevented by a silicone pad in which a silicone foam containing a flame retardant filler and a platinum-based flame retardant is integrally provided on one or both sides of the thermal diffusion sheet. To provide a silicone pad for battery thermal runaway delay and a battery pack including the same.

The present invention is provided with a silicone foam integrally on one side or both sides of the thermal diffusion sheet, wherein the silicone foam is made of a foam structure having a hardness (Shore OO) of 10 to 60 and a density of 0.20 to 0.45 (g / ㎤), and the thermal diffusion The sheet is made of a thermally conductive metal-based sheet or thermally conductive carbon (carbon)-based sheet, and a silicon pad for thermal runaway delay is installed as a buffer pad between battery cells, so that heat generated from one battery cell is transferred to another battery cell. It is designed to delay or prevent propagation.

The present invention has a multilayer structure in which a silicone foam having a foam structure is integrally formed via a thermal diffusion sheet, and has excellent thermal runaway delay performance due to a heat transfer delay effect by the silicone foam and a thermal diffusion effect by the thermal diffusion sheet there is

The silicone foam of the present invention is a flame retardant filler and phosphate-by mixing a platinum-based flame retardant consisting of a platinum complex, increase of flame retardancy by a flame retardant filler and a platinum-based flame retardant, and phosphate-carbonized layer due to a platinum-based flame retardant consisting of a platinum complex Through the formation, there is an effect that the thermal diffusion delay effect is further improved.

The present invention provides a non-flammable film made of glass wool, glass fiber, aramid film, ceramic film, or mica film on one or both sides, so that the thermal runaway delay performance is further improved in the high temperature range of 800 ° C. or more. There are many effects. .

1 is an exemplary view showing the configuration of a silicon pad for delaying thermal runaway of a battery according to the present invention;
2 is an exemplary view showing a thermal diffusion process of a silicon pad according to the present invention;
3 is another exemplary view showing the configuration of a silicon pad according to the present invention;
4 is an exemplary view of the reaction mechanism of the platinum-based flame retardant according to the present invention;
5 is an exemplary view showing the configuration of a battery pack including a silicon pad (buffer pad) for delaying thermal runaway of a battery according to the present invention;

1 is an exemplary view showing the configuration of a silicon pad for thermal runaway delay of a battery according to the present invention, Figure 2 is an exemplary view showing a thermal diffusion process of the silicon pad according to the present invention,

The silicone pad according to the present invention is provided with a silicone foam integrally on one or both sides of the thermal diffusion sheet,

The silicone foam is made of a foam structure having a hardness (Shore OO) of 10 to 60 and a density of 0.20 to 0.45 (g / ㎤), and the thermal diffusion sheet is a thermally conductive metal-based sheet or thermally conductive carbon (carbon)-based sheet. can be done

That is, the silicon pad 20 according to the present invention, as shown in (a) of FIG. 1, the thermal diffusion sheet 22 is integrally formed on one surface of the silicone foam 21, As shown in, the thermal diffusion sheet 22 may be configured such that the two silicone foams 21 are integrally formed.

The silicone foam 21 has a function of buffering the pressure (surface pressure) between the battery cells 110 and has a function of preventing thermal runaway by blocking heat diffusion according to the temperature rise of the battery cells.

The silicone foam 21 is, based on 100 parts by weight of polyorganosiloxane, 20 to 150 parts by weight of a flame retardant filler made of aluminum hydroxide or magnesium hydroxide, 0.01 to 1.0 parts by weight of a platinum-based flame retardant comprising a phosphate-platinum complex, a platinum catalyst 0.0001 to 0.1 parts by weight.

The silicone foam 21 made in this way is a flame retardant filler and a phosphate-platinum-based flame retardant composed of a platinum complex when the flame retardant is increased by mixing a platinum-based flame retardant consisting of a platinum complex, and thermal runaway occurs, phosphate-platinum-based flame retardant Due to the formation of a carbonized layer, it has a function of delaying thermal runaway.

The polyorganosiloxane is at least 30-60 wt% of a first polydiorganosiloxane having two or more unsaturated hydrocarbon groups, 30-60 wt% of a second polydiorganosiloxane having one or two hydroxyl groups, hydrogen at the terminal 5 to 38 wt% of a third polydihydrogen siloxane having groups, and 0.2 to 20 wt% of a fourth polydihydrogen siloxane having at least two or more hydrogen groups.

The first polydiorganosiloxane includes dimethyl siloxane in which both ends of the molecular chain are blocked by dimethylvinylsiloxane groups, dimethyl siloxane methylphenylsiloxane copolymer in which both ends of the molecular chain are blocked by dimethylvinylsiloxane groups, and both ends of the molecular chain It is a copolymer of dimethyl siloxane and methyl trifluoropropyl siloxane blocked with a dimethylvinylsiloxane group with a vinyl group content of 0.05 to 0.3 mmol/gram (mmol/gr) and a viscosity of 1,000 to 100,000 cp at 25°C. that is used

[Formula 1]

In the above [Formula 1], R1 is an unsubstituted or substituted group containing no aliphatic unsaturated bond, preferably a monovalent hydrocarbon having 1 to 10 carbon atoms, particularly, 1 to 5 carbon atoms, for example, a methyl group, an ethyl group , a lower alkyl group such as a propyl group or a butyl group, an aryl group such as a phenyl group, a xylyl group, or a benzene group, a cycloalkyl group such as a cyclohexyl group, or a part or all of the hydrogen atoms of these groups are A chloromethyl group, a cyanomethyl group, a 3,3,3,- trifluoropropyl group, etc., and n is 0 or a positive integer.

The second polydiorganosiloxane includes dimethyl siloxane in which both ends of the molecular chain are blocked by dimethylhydroxysiloxane groups, dimethyl siloxane methylphenylsiloxane copolymer in which both ends of the molecular chain are blocked by dimethylhydroxysiloxane groups, and molecular chain A copolymer of dimethyl siloxane and methyl trifluoropropyl siloxane whose both ends are blocked with dimethyl hydroxy siloxane groups, which do not contain unsaturated hydrocarbon groups and have a viscosity of 100 to 200,000 cp at 25°C is used.

[Formula 2]

In the above [Formula 2], R1 is an unsubstituted or substituted group containing no aliphatic unsaturated bond or preferably a monovalent hydrocarbon having 1 to 10 carbon atoms, particularly, 1 to 5 carbon atoms, for example, a methyl group, an ethyl group , a lower alkyl group such as a propyl group or a butyl group, an aryl group such as a phenyl group, a xylyl group, or a benzene group, a cycloalkyl group such as a cyclohexyl group, or a part or all of the hydrogen atoms of these groups are A chloromethyl group, a cyanomethyl group, a 3,3,3,- trifluoropropyl group, etc., and n is 0 or a positive integer.

The third polydihydrogen siloxane includes dimethyl siloxane in which both ends of the molecular chain are blocked by dimethylhydrogensiloxane groups, dimethyl siloxane methyl phenylsiloxane copolymer in which both ends of the molecular chain are blocked by dimethylhydrogensiloxane groups, and molecular chain A copolymer of dimethyl siloxane and methyl trifluoropropyl siloxane, both ends of which is blocked with dimethylhydrogensiloxane groups, which does not contain an aliphatic unsaturated hydrocarbon group and has a viscosity of 10 to 10,000 cp at 25°C is used.

[Formula 3]

In the above [Formula 3], R1 is an unsubstituted or substituted group containing no aliphatic unsaturated bond or preferably a monovalent hydrocarbon having 1 to 10 carbon atoms, particularly, 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, A lower alkyl group such as a propyl group or a butyl group; A methyl group, a cyanomethyl group, a 3,3,3,- trifluoropropyl group, etc., and n is 0 or a positive integer.

The fourth polydihydrogen siloxane is a copolymer of dimethylsiloxane and methylhydrogensiloxane in which both ends of the molecular chain are blocked with trimethylsiloxane groups, and has at least two hydrogen atoms bonded to silicon atoms in one molecule. Those containing 1 to 15 mol% of hydrogen groups of the entire device and having a viscosity of 100 to 20,000 cp at 25°C are used.

[Formula 4]

In [Formula 4], R1 and R4 are unsubstituted or substituted groups that do not contain an aliphatic unsaturated bond or are preferably monovalent hydrocarbons having 1 to 10 carbon atoms, particularly, 1 to 5 carbon atoms, for example, a methyl group, A lower alkyl group such as an ethyl group, a propyl group, or a butyl group, an aryl group such as a phenyl group, a xylyl group, or a benzene group, a cycloalkyl group such as a cyclohexyl group, or some or all of the hydrogen atoms of these groups are substituted with a halogen atom or a cyano group chloromethyl group, cyanomethyl group, 3,3,3,-trifluoropropyl group, etc., and n and m are 0 or positive integers.

)으로 이루어지고, 폴리오르가노 실록산 100 중량부에 대하여 20∼150 중량부, 바람직하게는 약 30∼100중량부가 사용된다. The flame-retardant filler is aluminum hydroxide (ATP) or magnesium hydroxide (

), and 20 to 150 parts by weight, preferably about 30 to 100 parts by weight, are used based on 100 parts by weight of the polyorganosiloxane.

The flame-retardant filler is preferably aluminum hydroxide (ATP), and the aluminum hydroxide (ATP) has a particle size of 5 to 60 μm, preferably 5 to 30 μm.

The aluminum hydroxide (ATP) has a function of improving the heat resistance of the silicone foam by reducing the temperature rise and suppressing the movement of combustion because it causes an endothermic reaction when a fire occurs.

That is, the aluminum hydroxide has a structure in which water molecules are mixed between silicas, and when heated, water molecules burst out of the gaps in the silica, and as a product of the combustion reaction, moisture and metal oxides, which are nonflammable agents, are generated, thereby causing combustion. By blocking the contact of phosphorus and oxygen, the thermal barrier properties of the silicone foam (sponge) are further improved.

When the aluminum hydroxide is added in less than 20 parts by weight, heat resistance improvement may not be properly implemented, and when it is added in excess of 150 parts by weight, the physical properties of the silicone foam (tear strength, elongation, tension, etc.) physical properties) may decrease rapidly, so it is added within the appropriate range.

The platinum-based flame retardant is added to impart flame retardancy while improving the mechanical strength and heat resistance of silicone rubber, and consists of a platinum-based flame retardant in which platinum is complexed with phosphate.

The platinum-based flame retardant comprising the phosphate-platinum complex has a function of reinforcing the deterioration of the physical properties of silicone rubber and delaying thermal diffusion by increasing the flame retardant effect.

In particular, the platinum-based flame retardant composed of the phosphate-platinum complex forms a carbonized layer (carbon film) by reaction with silicon (polysiloxane) when thermal runaway occurs, thereby further delaying thermal diffusion between battery cells.

In addition, the platinum-based flame retardant composed of the phosphate-platinum complex, for example, a platinum-based flame retardant according to the following [Formula 5] may be used.

[Formula 5]

4 shows an exemplary view of the reaction mechanism of the platinum-based flame retardant according to the present invention, the mechanism of the radical addition reaction of TPP (trypheny phosphite) at the end of PDMS (polydimethyl siloxane) is shown. As such, when the temperature of the battery cell increases, the platinum-based flame retardant according to the present invention is added reacted by thermal decomposition to form a carbonized layer on the silicon side, through which the supply/contact of oxygen is blocked and thermal diffusion A function to delay this is provided.

In addition, since the platinum-based flame retardant according to the present invention forms a hard carbonized layer on the surface of the silicone foam (sponge), the structure of the silicone foam (sponge), that is, the foam structure, is maintained by the carbonized layer to prevent thermal runaway propagation. It has the effect of further delaying.

)은 우수한 난연성을 구비하고 있으나, 고온 발생 시, 실리콘 고무의 물리적 특성 및 내열성을 저하시키는 현상이 발생될 수 있다. In addition, the formation of the carbonized layer of the platinum-based flame retardant as described above has a function of preventing deterioration of the physical properties of the silicone rubber due to the addition of the flame retardant filler. That is, aluminum hydroxide (ATT) or magnesium hydroxide (

) has excellent flame retardancy, but when high temperature occurs, a phenomenon may occur that deteriorates the physical properties and heat resistance of silicone rubber.

)로 이루어진 난연성 필러와 함께 백금계 난연제가 혼합 첨가되므로, 실리콘 측면의 표면에 딱딱하게 생성되는 탄화층에 의해 열 확산 및 폼의 분해가 방지되어, 고온 발생 시, 난연성 필러의 첨가로 인한 실리콘 고무의 물성 및 내열성 저하현상이 방지되는 효과가 있다. However, in the present invention, aluminum hydroxide (ATT) or magnesium hydroxide (

), as a platinum-based flame retardant is mixed and added together with a flame retardant filler, heat diffusion and decomposition of the foam are prevented by the carbonized layer that is formed hard on the surface of the silicone side. It has the effect of preventing deterioration of physical properties and heat resistance.

The platinum-based flame retardant is used in an amount of 0.01 to 1.0 parts by weight, preferably 0.01 to 0.5 parts by weight, based on 100 parts by weight of the polyorganosiloxane.

When the platinum-based flame retardant is used in less than 0.01 parts by weight, improvement of the flame retardancy cannot be expected, and when it is added in excess of 1.0 parts by weight, a phenomenon that the flame retardance is rather deteriorated occurs, so it is added within an appropriate range.

In addition, the platinum-based flame retardant may be used by dispersing it in an organic solvent such as alcohol, isopropyl alcohol, benzene, or xylene.

The platinum-based catalyst is platinum or a platinum compound, and a known platinum-based catalyst used in the manufacture of silicon is used. A single platinum or platinum compound is used as the platinum-based catalyst. The platinum-based catalyst is, for example, a single platinum (Pt), H ₂ PtCl ₆ ·nH ₂ O, NaHPtCl ₆ ·nH ₂ O, KHPtCl ₆ ·nH ₂ O, NaPtCl ₆ ·nH ₂ O, K ₂ PtCl ₆ · nH ₂ O, PtCl ₄ .nH ₂ O, PtCl ₂ , NaPtCl ₄ .nH ₂ O, and H ₂ PtCl ₄ .nH ₂ O, and the like.

In addition, the present invention may further include 0.01 to 10 parts by weight of silica for reinforcement of durability and flame retardancy.

The silicone foam 21 configured as described above is room temperature curable, has a foam structure having a hardness (ShoreOO) of 20 to 60, a density of 0.20 to 0.45 (g/cm 3 ), has rubber elasticity, and is a battery cell It expands and contracts according to the pressure (surface pressure) between them and has a buffer function.

In addition, the silicone foam 21 is composed of a foam structure containing a flame retardant filler and a platinum-based flame retardant, and has the effect of delaying thermal runaway for about 240 sec or more in a high temperature region of 600 ° C or higher where thermal runaway occurs (600 ° C.) It has the effect of delaying the time it takes for the heat source to reach the opposite side of the 3.5mm-thick silicone foam to 150°C for more than 240 seconds).

The thermal diffusion sheet 22 has a function of diffusing high-temperature heat when a thermal runaway phenomenon occurs to minimize heat transfer to the silicon foam or another battery cell to achieve a thermal runaway delay effect.

That is, since the thermal runaway phenomenon of the battery cell does not occur simultaneously over the entire area of the battery cell, but partially occurs, the thermal diffusion sheet 22 thermally diffuses the partially generated heat as shown in FIG. It has a function of rapidly diffusing heat A throughout the sheet 22 so that heat transfer B to the silicon foam 21 or another neighboring battery cell is minimized.

As the thermal diffusion sheet 22, a metal-based sheet or carbon (carbon)-based sheet having thermal conductivity is used.

The metal-based sheet is selected from one of the sheets having thermal conductivity such as an aluminum foil sheet, a copper foil sheet, a nickel sheet, and the like, and the carbon (carbon)-based sheet is a graphite sheet, a carbon fiber sheet, a graphene sheet, etc. Thermal diffusivity One of the sheets having (thermal conductivity) may be selected, and the thermal diffusion sheet 22 is most preferably made of an aluminum foil sheet or a copper foil sheet.

In addition, as the thermal diffusion sheet 22, a sheet of various materials having thermal conductivity and thermal diffusivity in addition to a metal-based sheet or carbon (carbon)-based sheet having thermal conductivity may be used.

The thermal diffusion sheet 22 made as described above has a thickness of 0.03 mm to 2.0 mm, and preferably has a thickness of about 0.03 mm to 1.0 mm. That is, when the thickness is less than 0.03 mm, the thermal diffusion effect is insignificant, and when the thickness exceeds 2.0 mm, the overall thickness of the silicon pad 20 is thickened, and the elasticity of the silicon pad 20 is lowered between the battery cells. The buffer function is reduced by the surface pressure. In addition, when the thickness of the thermal diffusion sheet 22 exceeds 2.0 mm, there is no significant difference in the thermal diffusion effect, so it is preferable to have a thickness within an appropriate range.

In addition, as shown in FIG. 3 , the silicon pad 20 for delaying thermal runaway of a battery according to the present invention is provided with a non-combustible film 23 on both sides integrally, so that the thermal runaway phenomenon at high temperature is further delayed. can be configured.

The non-flammable film 23, glass wool, aramid film, MICA film, ceramic film, asbestos, etc. may be used, and a thickness of 50 μm to 2,000 μm, preferably, a thickness of about 100 to 500 μm is used.

In addition, the incombustible film 23 is preferably provided integrally on both surfaces of the silicon pad 20 , but may be configured to be integrally provided on one surface of the silicon pad 20 .

As described above, the silicon pad 20 according to the present invention in which the silicone foam 21 and the thermal diffusion sheet 22 are integrally formed has a thickness of about 1.5 mm to 15 mm, preferably about 2.5 mm to 10 mm, more preferably It may be formed to have a thickness of about 2.5 mm to 5 mm.

That is, the silicon pad 20 according to the present invention may be configured such that the silicon foam 21 and the thermal diffusion sheet 22 are integrally provided within a thickness of about 1.5 mm to 15 mm, and the silicone foam and the thermal diffusion sheet Although the thickness ratio of the is not limited, it is preferable that the thickness of the thermal diffusion sheet is minimized and the remainder is made of silicon foam.

For example, when the silicon pad 20 is made of a thickness of about 2.5 mm, the thermal diffusion sheet 22 has a thickness of 0.03 mm, and the rest may be configured to be made of a silicon foam 21,

When the silicon pad 20 is made of a thickness of about 2.5 mm, the thermal diffusion sheet 22 has a thickness of 0.1 mm, and the rest may be configured to be made of a silicon foam 21,

When the silicon pad 20 is made of a thickness of about 2.5 mm, the thermal diffusion sheet 22 has a thickness of 1.0 mm, and the rest may be configured to be made of a silicon foam 21,

When the silicon pad 20 has a thickness of about 2.5 mm, the thermal diffusion sheet 22 may have a thickness of 2.0 mm, and the rest may be configured with the silicon foam 21 .

As described above, the silicon pad 20 for battery thermal runaway delay according to the present invention in which the silicon foam 21 and the thermal diffusion sheet 22 are integrally formed is a silicon pad made of only silicon foam without a thermal diffusion sheet (for example, the present invention). When compared with Patent Application No. 10-2021-0042760) filed by the applicant of , it has a significant thermal runaway delay effect.

That is, when the silicon pad is made of only silicon foam, a silicon pad having a thickness of about 3.5 mm has an effect of delaying thermal runaway for about 240 sec or more in a high temperature region of 600 ° C or higher where thermal runaway occurs (a heat source of 600 ° C. It has the effect of delaying the time it takes for the temperature to reach the opposite side of the 3.5mm thick silicone foam to rise to 150°C for more than 240 seconds),

The silicone pad 20 for battery thermal runaway retardation according to the present invention has a thin thickness of about 2.5 mm (silicone foam 2.45 mm - aluminum foil thermal diffusion sheet 0.05 mm or silicon foam 1.225 mm - aluminum foil thermal diffusion sheet 0.05 mm - silicone foam 1.225mm), the effect of delaying thermal runaway for about 10 minutes or more when 900℃ thermal runaway occurs It has the effect of delaying the time by more than 10 minutes),

It can be seen that the silicon pad 20 for delaying thermal runaway of a battery according to the present invention has a more excellent thermal runaway delay effect when compared with a silicon pad made of only silicon foam.

In addition, since the integration of the silicone foam 21 and the thermal diffusion sheet 22 is made by a known manufacturing method, a detailed description thereof will be omitted. For example, before curing of the silicone foam, the thermal diffusion sheet may be mounted and integrated, and the silicone foam may be coated/cured on the thermal diffusion sheet to be integrated.

5 is an exemplary view showing the configuration of a battery pack including a silicon pad (buffer pad) for delaying thermal runaway of the battery according to the present invention;

A battery pack (100) having a battery module (30) in which a silicon pad (20) is disposed between a plurality of stacked battery cells (10) in a case (40);

The silicon pad 20 is provided with a silicone foam 21 integrally on one or both sides of the thermal diffusion sheet 22,

The silicone foam 21 is made of a foam structure having a hardness (Shore OO) of 10 to 60 and a density of 0.20 to 0.45 (g/cm 3 ), and the thermal diffusion sheet 22 is a thermally conductive metal-based sheet or thermally conductive carbon. It may consist of a (carbon) series sheet.

At this time, the silicone foam 21, based on 100 parts by weight of polyorganosiloxane, 20 to 150 parts by weight of a flame retardant filler made of aluminum hydroxide or magnesium hydroxide, 0.01 to 1.0 parts by weight of a platinum-based flame retardant consisting of a phosphate-platinum complex, containing 0.0001 to 0.1 parts by weight of a platinum catalyst,

The metal-based sheet is selected from one of sheets having thermal conductivity such as an aluminum foil sheet, a copper foil sheet, a nickel sheet, and the like, and the carbon (carbon)-based sheet is a graphite sheet, a carbon fiber sheet, a graphene sheet, etc. Thermal diffusivity One of the sheets with (thermal conductivity) may be selected.

In addition, the silicon pad 20, a non-combustible film 23 may be further provided on both sides, and the non-combustible film 23, glass wool, aramid film, MICA film, ceramic film, asbestos, etc. may be used. . At this time, the thickness of the non-flammable film 23 is 50 um to 2,000 um, preferably one having a thickness of about 100 to 500 um is used.

In the battery pack of the present invention configured as described above, a silicon pad 20 of a multilayer foam structure having a thickness of 1.5 to 15 mm, preferably about 2.5 to 5.0 mm, is installed as a buffer pad between the battery cells. I have,

The silicone pad 20 expands and contracts according to the absorption power of the cell, that is, according to the pressure (surface pressure), and when a fire occurs, the flame retardancy is increased by the flame retardant filler in the silicone foam 21, and the chain As a result, a hard carbonized layer is formed on the surface of the silicon foam 21 by a platinum-based flame retardant composed of a phosphate-platinum complex, and has a function of delaying the thermal runaway phenomenon generated in one battery cell from propagating to another battery cell. In addition, by thermal diffusion (A) by the thermal diffusion sheet 22, heat transfer (B) to the silicon foam 21 or another neighboring battery cell is minimized, so that the thermal runaway phenomenon is further delayed. do.

In FIG. 5 , reference numeral 50 denotes a cooling plate, 60 denotes a thermal barrier foam, and 70 denotes a seal. The battery pack shown in FIG. 1 is an example, and the configuration of the battery pack according to the present invention is limited to FIG. 5 . it's not going to be

Hereinafter, the present invention will be described in detail by way of Examples.

Example 1

After preparing a specimen by mixing a silicone polymer and an inorganic flame retardant (flame retardant filler) in a mixing ratio according to [Table 1] below, the thermal diffusion delay effect on the specimen was measured, and the results are shown in [Table 1]. In [Table 1], the silicone polymer is at least 42 wt% of a first polydiorganosiloxane having two or more unsaturated hydrocarbon groups, 42 wt% of a second polydiorganosiloxane having one or two hydroxyl groups, a hydrogen group at the terminal With respect to 100 parts by weight of the polyorganosiloxane containing 10 wt% of the third polydihydrogen siloxane and 6 wt% of the fourth polydihydrogen siloxane having at least two hydrogen groups, the platinum catalyst is added in a proportion of 0.01 parts by weight. means added.

[Table 1]

As shown in Table 1 above, in the silicone pad according to the present invention, it is more effective to add aluminum hydroxide and magnesium hydroxide as an inorganic flame retardant (flame retardant filler), rather than the addition of calcium carbonate, which is widely used as an inorganic flame retardant. it can be seen that In particular, in the present invention, it can be seen that aluminum hydroxide is the most effective as an inorganic flame retardant (flame retardant filler).

Example 2

The thermal diffusion delay effect according to the amount of the inorganic flame retardant (aluminum hydroxide) added was measured, and the results are shown in [Table 2] below. At this time, the same silicone polymer as in Example 1 was used.

[Table 2]

As shown in [Table 2] above, in the present invention, although there is some difference in thermal conductivity depending on the amount of aluminum hydroxide added, it can be seen that when 600 ° C is applied, the temperature reached to the opposite side is maintained below 240 ° C.

Example 3

Based on the specimen 7 according to Example 2, the thermal diffusion delay effect according to the addition of the platinum-based flame retardant was measured, and the results are shown in [Table 3] below. At this time, the same silicone polymer as in Example 1 was used.

[Table 3]

As shown in [Table 3] above, when platinum-based flame retardants are added, it can be seen that the temperature reached to the opposite side is maintained below 220 °C when 600 °C is applied, and through this, only aluminum hydroxide is added It can be seen that the thermal diffusion delay effect is further improved compared to the specimen. It can be seen that the alumina is formed by decomposition of aluminum hydroxide and the flame retardancy is increased, and a hard carbonized layer is formed on the surface by the platinum-based flame retardant in a chain, and it can be seen that the thermal diffusion delay effect is improved as a whole.

Example 4

The thermal diffusion delay effect was measured for the specimen in which the non-combustible film was integrated (based on specimen 15 according to Example 3), and the results are shown in [Table 4] below. At this time, the same silicone polymer as in Example 1 was used.

[Table 4]

As shown in [Table 4] above, when a non-combustible film is further included, it can be seen that the temperature reached to the opposite side is maintained at less than 160 °C at 300 sec when 600 ° C is applied, and through this, according to the present invention It can be seen that when glass wool, glass fiber, aramid film, ceramic film or mica film is compounded on one or both sides of the silicone pad for battery thermal runaway retardation, the thermal runaway retardation effect is greatly improved.

Example 5

Based on Specimen 15 of Example 3, the thermal diffusion delay effect was measured by integrating the non-combustible film, the non-flammable film and the thermal diffusion film, and the results are shown in [Table 5] below. At this time, the same silicone polymer as in Example 1 was used.

[Table 5]

As shown in [Table 5] above, when a non-flammable film (both sides) and a thermal diffusion film are further included, it can be seen that when 900 ° C is applied, the temperature reached to the opposite side is maintained below 200 ° C at 400 sec, and this Through this, it can be seen that when a non-combustible film is integrated on both sides of the silicone pad for delaying thermal runaway of a battery according to the present invention including a thermal diffusion film, the thermal runaway delay effect is greatly improved.

The present invention is not limited to the specific preferred embodiments described above, and various modifications can be made by anyone with ordinary skill in the art to which the invention pertains without departing from the gist of the invention as claimed in the claims. Of course, such modifications are intended to be within the scope of the claims.

In addition, the terms described in the present invention are for distinguishing one element from other elements and helping the understanding of the present invention, so the elements of the present invention should not be limited by the described terms.

(10): battery cell (20): silicone pad
(21): silicone foam (22): thermal diffusion sheet
(23): Non-combustible film (30): Battery module
(40): case (50): cooling plate
(60): Thermal insulation foam (70): Seal

Claims (6)

A silicon foam 21 is integrally provided on one or both sides of the thermal diffusion sheet 22 having a thickness of 0.03 mm to 2.0 mm, which is made of a metal-based sheet or carbon (carbon)-based sheet having thermal conductivity, and a thickness of 1.5 It consists of a silicon pad 20 integrally provided with a silicone foam 21 and a thermal diffusion sheet 22 within the range of mm to 15 mm,
The silicone foam 21 is, based on 100 parts by weight of polyorganosiloxane, 20 to 150 parts by weight of a flame retardant filler made of aluminum hydroxide or magnesium hydroxide, 0.01 to 1.0 parts by weight of a platinum-based flame retardant comprising a phosphate-platinum complex, a platinum catalyst 0.0001 to 0.1 parts by weight,
The polyorganosiloxane is at least 30-60 wt% of a first polydiorganosiloxane having two or more unsaturated hydrocarbon groups, 30-60 wt% of a second polydiorganosiloxane having one or two hydroxyl groups, at the terminal 5 to 38 wt% of a third polydihydrogen siloxane having a hydrogen group, and 0.2 to 20 wt% of a fourth polydihydrogen siloxane having at least two hydrogen groups,
The platinum-based flame retardant is composed of a phosphate-platinum complex according to the following [Formula 5], with a thermal diffusion sheet, characterized in that it has a foam structure of 10 to 60 hardness (Shore OO) and 0.20 to 0.45 (g / ㎤) density. Silicone pad for one battery thermal runaway delay.
[Formula 5]

The method of claim 1 ;
The metal-based sheet consists of one selected from an aluminum foil sheet, a copper foil sheet, and a nickel sheet,
The carbon (carbon)-based sheet is a silicon pad for battery thermal runaway delay having a thermal diffusion sheet, characterized in that it is made of one selected from a graphite sheet, a carbon fiber sheet, and a graphene sheet.
delete delete The method of claim 1 ;
A non-combustible film 23 is further provided on both sides of the silicon pad 20,
The non-combustible film 23 is a silicone pad for battery thermal runaway delay having a thermal diffusion sheet, characterized in that one selected from glass wool, aramid film, MICA film, ceramic film, and asbestos.
A battery pack in which a plurality of battery cells are stacked in a case, and a buffer pad is disposed between the battery cells;
The buffer pad is a battery pack, characterized in that made of the silicon pad according to claim 1 or 5.

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