Potting compounds for electrocellular cells and methods for producing them

Abstract

To provide a battery module comprising an electrolytic cell and a potting compound associated with the electrolytic cell. [Solution] The potting compound is formed of a first component having a flame retardant component, an isocyanate-reactive compound, and water, and a second component having an isocyanate compound. The potting compound is a foam.

Description

[Technical Field]

[0001] This disclosure relates to a battery module comprising an electrical cell positioned within a potting compound. More specifically, this disclosure relates to a battery module comprising an electrical cell positioned within a foam potting compound containing a flame retardant. [Background technology]

[0002] Generally, potting is the process of partially or completely filling or embedding a material into an enclosure for the purpose of maintaining the spatial relationships between objects within the enclosure and with respect to the enclosure itself. Potting can be used to provide resistance to shock and vibration. Specific compositions used for potting may be designed to create a seal against moisture, solvents, and corrosive substances.

[0003] The materials used to form potting compounds vary in hardness from very soft to very hard, and are designed to withstand a variety of environments. Potting compounds used for potting electrical cells may be designed to provide mechanical stability and impact resistance to battery modules intended for use in vehicles, for example. There is a need for potting compounds that provide mechanical stability to electrical cells while adding minimal weight to the battery module. There is also a need for potting compounds for use in battery modules that provide mechanical stability to electrical cells and are flame-retardant. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 2011 / 192564 [Patent Document 2] U.S. Patent Application Publication No. 2011 / 250475 [Patent Document 3] U.S. Patent Application Publication No. 2012 / 003508 [Patent Document 4] U.S. Patent Application Publication No. 2012 / 183819 [Patent Document 5] Japanese Patent Publication No. 2011-148903 [Overview of the project]

[0005] This specification discloses a battery module comprising an electric cell and a potting compound associated with the electric cell. The potting compound is formed of a first component having a flame retardant component, an isocyanate-reactive compound, and water, and a second component having an isocyanate compound. The potting compound is a cured foam.

[0006] The potting compound may have at least V2 level flame resistance as measured by UL94 "Test for Flammability of Plastics". The potting compound is 0.50 g / cm³. 3 It may have a foam density of less than . The flame retardant component may be present in an amount of at least 15% by weight based on the total weight of the potting compound. The flame retardant component may be present in an amount of at least 30% by weight based on the total weight of the potting compound. The potting composition configured to form the potting compound may have sufficient fluidity before curing so that it stabilizes at a horizontal height around the electric cell.

[0007] The first component may have a viscosity of more than 1 but less than 100,000 cp. The second component may have a viscosity of more than 1 but less than 50,000 cp at a temperature of approximately 25°C to approximately 35°C. The first component may have a viscosity of more than 1 but less than 1,500 cp. The second component may have a viscosity of more than 1 but less than 1,000 cp at a temperature of approximately 25°C to approximately 35°C.

[0008] Also disclosed herein are battery modules comprising electric cells positioned within a potting compound. The potting compound may be formed from a reaction product of a first component having an isocyanate-reactive compound and a second component having an isocyanate compound. The potting compound may further comprise a blowing agent and a liquid flame retardant component present in an amount of about 15% to about 60% by weight based on the total weight of the potting compound.

[0009] The liquid flame retardant may contain a phosphate ester. The isocyanate-reactive compound may be a polyether polyol. The isocyanate-reactive compound may have an isocyanate-reactive functional value of 3 or more. The isocyanate compound may have an average isocyanate functional value of 2 or more.

[0010] The first component may have a viscosity of more than 1 but less than 100,000 cp. The second component may have a viscosity of more than 1 but less than 50,000 cp at a temperature of about 25°C to about 35°C. The first component may have a viscosity of more than 1 but less than 1,500 cp. The second component may have a viscosity of more than 1 but less than 1,000 cp at a temperature of about 25°C to about 35°C.

[0011] This specification also discloses a battery module comprising a first electrical cell positioned within a polyurethane foam potting compound. The potting compound is 0.50 g / cm³. 3 It has a density of less than . The foam potting compound may have flame resistance of at least V2 level when measured by UL94 "Plastics Material Flammability Test". The potting compound may be formed from a potting composition that has sufficient fluidity before curing so as to be dispersed substantially horizontally between the first electric cell and the battery module case positioned around the first electric cell.

[0012] Although multiple embodiments are disclosed, further other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description showing and explaining exemplary embodiments of the present disclosure. Therefore, the drawings and the detailed description should be considered to be illustrative in nature and not restrictive.

Brief Description of the Drawings

[0013] [Figure 1] Perspective view of a battery module according to a specific embodiment. [Figure 2] Top view of a battery module according to some embodiments. [Figure 3] Front view of a battery module according to some embodiments. [Figure 4] Perspective view of a battery module according to a specific embodiment. [Figure 5] Top view of a battery module according to some embodiments. [Figure 6] Exploded view of a battery module according to some embodiments.

Modes for Carrying Out the Invention

[0014] In this specification, a potting compound that is low density and flame retardant is disclosed. The potting compound has at least a V2 level of flame resistance when measured by UL94 "Plastics Materials Flammability Test". In some cases, the potting compound may have at least a V1 level of flame resistance when measured by UL94 "Plastics Materials Flammability Test". In some embodiments, the potting compound may have at least a V0 level of flame resistance when measured by UL94 "Plastics Materials Flammability Test". <>

[0015] Potting compounds can be formed from potting compositions, which are applied as liquids and cured to form potting compounds. Potting compositions have sufficient fluidity before curing to allow the potting composition to be applied as a liquid around electrical cells and then stabilize at substantially horizontal height around the electrical cells. The potting compositions disclosed herein can be applied as liquids and flow around electrical cells and between adjacent electrical cells before curing to form potting compounds. Potting compounds are useful for potting electrical cells to form lightweight battery modules. Potting compounds are useful for potting electrical cells and providing mechanical stability and flame retardancy after curing.

[0016] The potting compound may be formed from a material that forms a foam when cured, including silicone, epoxy, such as a one- or two-component epoxy resin, or polyurethane. In some embodiments, the potting compound includes a polyurethane foam. The potting compound may be formed from a polyurethane composition that is liquid before curing and hardens as a foam to form the potting compound. In some embodiments, the potting compound is formed from a polyurethane foam having low density and containing a flame retardant.

[0017] As used herein, a foam is defined as a material formed from a bulk material that defines cavities throughout the material. These cavities can be filled with gas, such as air, oxygen, carbon dioxide, nitrogen, or any suitable gas. The cavities form a cellular structure throughout the bulk material. For example, a potting composition may be a liquid mixture formed of components that react with each other and release gases that form bubbles throughout the liquid. A liquid potting composition hardens upon curing to form a solid potting compound, which is a solid material having cavities throughout the solid. The cavities result in a solid material with a lower density than if the solid material were entirely formed from a bulk material without a cellular structure. A foam can be closed-cell or open-cell. A closed-cell foam refers to a foam having cavities that form separate pockets completely surrounded by the solid material. An open-cell foam refers to a foam having cavities that form pockets connected to each other.

[0018] It is further conceivable that in some cases, low-density potting compounds may be formed by bulk material containing inflated or uninflated microballoons, such as syntactic foam. For example, solid particles formed from glass or polymer materials may be used to form three-dimensional shapes such as beads or bubbles that define gas-filled centers. The beads or bubbles can be dispersed throughout the bulk material, which can then be cured and trapped, thus reducing the overall density of the cured potting compound.

[0019] After curing, the potting compound, which is a foam, has a lower density than the potting composition, which is a liquid. In some embodiments, the potting compound has a density of about 0.60 g / cm³ after curing. 3 Less than approximately 0.50 g / cm³ 3 Less than approximately 0.40 g / cm³ 3 Less than approximately 0.30 g / cm³ 3 Less than approximately 0.20 g / cm³ 3 Less than approximately 0.10 g / cm³3 less than, or about 0.05 g / cm 3 has a density less than. For example, the potting compound has a density of about 0.02 g / cm 3 , about 0.05 g / cm 3 , about 0.10 g / cm 3 , about 0.20 g / cm 3 to about 0.30 g / cm 3 , about 0.40 g / cm 3 , or 0.50 g / cm 3 and can be a foam having a foam density between any pair of the above values, although potting compounds having additional densities are further contemplated.

[0020] The potting composition can be a two-component composition formed from a first component that reacts with a second component. At least one of the first component or the second component can contain a flame retardant. The first component and the second component can be selected to form a thermoplastic polyurethane component (TPU). After mixing the first component and the second component, the potting composition can be a formulation of a polyurethane component and a liquid flame retardant component. The first component and / or the second component can also contain one or more additional additives. The first component

[0021] The first component is liquid at room temperature (about 25°C to about 35°C). For example, the first component has a viscosity of greater than 1 to less than 100,000 centipoise (cP) at room temperature. In some embodiments, the first component has a viscosity of about 100 cP, about 200 cP, about 300 cP, or about 400 cP to about 1100 cP, about 1200 cP, about 1300 cP, or about 1400 cP, about 10,000, about 20,000, about 30,000, about 40,000, or 100,000, or a viscosity between any pair of the above values, although components having alternative viscosities are further contemplated.

[0022] The first component comprises one or more isocyanate-reactive compounds. The isocyanate-reactive compounds may be compounds containing active hydrogen, such as amines, alcohols, or thiols. The first component comprises an isocyanate-reactive compound having a functional value of 2 or more. A preferred isocyanate-reactive compound has a functional value of 3 or more. A preferred isocyanate-reactive compound is liquid at room temperature. A preferred isocyanate-reactive compound has low viscosity at room temperature. For example, a preferred isocyanate-reactive compound may have a viscosity of greater than 1, less than about 800 cP, less than about 700 cP, less than about 600 cP, or less than about 500 cP at room temperature. Preferred examples of isocyanate-reactive compounds include those having a viscosity of less than about 200 cP, less than about 190 cP, less than about 180 cP, or less than about 170 cP at room temperature (about 25°C to about 35°C).

[0023] Isocyanate-reactive compounds can be polyols. They can also be combinations of two or more polyols. For example, isocyanate-reactive compounds can be diol polyols, triol polyols, tetrapolyols, or higher-order polyols, or combinations thereof. Suitable examples of polyols that can be used as isocyanate-reactive compounds include those with low viscosity at room temperature.

[0024] The polyol may be selected from the group consisting of polyether polyols and polyester polyols. Suitable polyether polyols include, but are not limited to, polyoxyalkylene polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polybutylene glycol, as well as mixtures and combinations thereof. In some embodiments, suitable polyethers have a number average molecular weight (M) ranging from about 200, about 300, about 400, about 600 to about 800, about 1,000, about 4,000, or about 6,000. n Further polyethers may be conceivable that have molecular weights between ) or any pair of the above values, but with additional molecular weights.

[0025] In some embodiments, suitable polyols may include polyhydroxy ethers containing substituted or unsubstituted polyalkylene ether glycols or polyhydroxy polyalkylene ethers; polyhydroxy polyesters; ethylene or propylene oxide adducts of polyols and substituted esters of glycerol; polymerized polymer polyols polymerized in situ, such as graft polyols containing a certain proportion of vinyl monomer; and mixtures and combinations thereof. A further example of a suitable polyol is poly(diethylene glycol adipate).

[0026] In some embodiments, homopolymers and copolymers of polyoxyalkylenes may be used. In some embodiments, the copolymers of polyoxyalkylene polyols may include adducts of at least one compound comprising ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 2-ethylhexanediol-1,3, glycerin, 1,2,6-hexanetriol, trimethylolpropane, trimethylolethane, tris(hydroxyphenyl)propane, triethanolamine, and triisopropanolamine; as well as one compound comprising ethylene oxide, propylene oxide, and butylene oxide.

[0027] In some embodiments, suitable polyester polyols can be formed from the reaction of one or more polyhydric alcohols having about 2 to about 15 carbon atoms with one or more polycarboxylic acids having about 2 to about 14 carbon atoms. Examples of suitable polyhydric alcohols include ethylene glycol, propylene glycol such as 1,2-propylene glycol and 1,3-propylene glycol, glycerol, pentaerythritol, trimethylolpropane, 1,4,6-octanetriol, butanediol, pentanediol, hexanediol, dodecadiol, octanetriol, chloropentanediol, glycerol monoalkyl ether, glycerol monoethyl ether, diethylene glycol, 2-ethylhexanediol, 1,4-cyclohexanediol, 1,2,6-hexanetriol, 1,3,5-hexanetriol, 1,3-bis-(2-hydroxyethoxy)propane, and similar components.

[0028] In some embodiments, the isocyanate-reactive compound is present in the first component in weight percentages of about 20 percent, about 30 percent, or about 40 percent to about 70 percent, about 80 percent, about 90 percent, or about 100 percent, or any pair of weight percentages between the above values, based on the total weight of the first component. In preferred embodiments, the isocyanate-reactive compound is present in the first component in weight percentages of about 20 percent, about 25 percent, or about 30 percent to about 35 percent, about 40 percent, about 45 percent, or about 50 percent, based on the total weight of the first component, or any pair of weight percentages between the above values. In embodiments having more than one isocyanate-reactive compound, the total amount of all isocyanate-reactive compounds present in the first component is a combined weight percentage of about 20 percent, about 30 percent, or about 40 percent to about 70 percent, about 80 percent, about 90 percent, or about 100 percent, based on the total weight of the first component, or any pair of weight percentages between the above values.

[0029] Suitable commercially available polyols that can be used to form polyurethane potting compositions include the triol polyether polyol sold under the trade name Poly G 30-240 (available from Monument Chemical Group in Houston, TX), the triol polyether polyol sold under the trade name VORANOL 230-238 (available from Dow Chemical Company in Midland, MI), and the polyether polyol sold under the trade name ARCOL LHT-240 (Covestro AG in Leverkusen, Germany). Second component

[0030] The second component is liquid at room temperature (approximately 25°C to 35°C). The second component has a viscosity of greater than 1 to less than 50,000 centipoise (cP) at room temperature. For example, the second component may have a viscosity of approximately 40 cP, approximately 60 cP, approximately 80 cP, or approximately 100 cP at room temperature (approximately 25°C to 35°C) to approximately 600 cP, approximately 700 cP, approximately 800 cP, approximately 900 cP, approximately 1,000, approximately 10,000, approximately 20,000, approximately 30,000, or approximately 50,000, or a viscosity between any pair of the above values, but components with alternative viscosities may be further conceived. In a preferred embodiment, the second component has a viscosity of 200 cP or less at room temperature.

[0031] The second component comprises an isocyanate compound. The isocyanate compound has an average isocyanate functional value of 2 or more. Suitable isocyanate compounds include those that are liquid at room temperature (approximately 25°C to approximately 35°C) and have a viscosity of 300 cP or less, approximately 200 cP or less, or approximately 100 cP or less. In some embodiments, the isocyanate compound may be a monomer. In some embodiments, the isocyanate compound may be a prepolymer. For example, the isocyanate compound may be a polymer that reacts with an isocyanate compound, such as an isocyanate-terminated oligomer. In some embodiments, the isocyanate compound may be a polymeric isocyanate.

[0032] Suitable isocyanate compounds include, but are not limited to, aromatic isocyanates such as aromatic diisocyanates, or aliphatic isocyanates such as aliphatic diisocyanates. In some embodiments, the isocyanate compound has 1 to 10 aliphatic or aromatic groups substituted by isocyanates.

[0033] Suitable isocyanate compounds include diphenylmethane diisocyanate (MDI), methylenediphenyl diisocyanate (MDI), carbodiimide-modified MDI, hydrogenated methylenediphenyl isocyanate (HMDI), hexamethylenediisocyanate (HDI), isophorone diisocyanate (IPDI), polymeric methylenediphenyl isocyanate, diphenylmethane-4,4'-diisocyanate, and diphenylmethane-2,2'-diisocyanate. Examples include methylene diphenyl isocyanate compounds such as diphenylmethane-2,4'-diisocyanate and other oligomeric methylene isocyanates; toluene diisocyanate compounds (TDI), tetramethylxylene diisocyanate (TMXDI), naphthylene diisocyanate isomers, triphenylmethane triisocyanate isomers, and mixtures and combinations thereof, but additional isocyanates may be conceived. In some examples, aliphatic di, tri, and polyisocyanates, including, for example, hydrogenated aromatic diisocyanates, aliphatic polyisocyanates, or cycloaliphatic polyisocyanates, are also preferred isocyanate compounds, but additional isocyanates may be conceived. Suitable commercially available isocyanate compounds include modified liquid MDI sold under the trade name ISONATE 143L (available from The Dow Chemical Company in Midland, MI) or polymeric MDI sold under the trade name RUBINATE M (available from Huntsman Corporation in Woodlands, TX).

[0034] In some embodiments, the isocyanate compound is present in the second component in weight percentages ranging from about 20 percent, about 30 percent, or 40 percent to about 70 percent, about 80 percent, about 90 percent, or about 100 percent, based on the total weight of the second component, or in weight percentages between any pair of the above values. In preferred embodiments, the isocyanate compound is present in the second component in weight percentages ranging from about 50 percent, about 55 percent, or about 60 percent to about 70 percent, about 75 percent, about 80 percent, or about 85 percent, based on the total weight of the second component, or in weight percentages between any pair of the above values. In embodiments having more than one isocyanate compound, the total amount of all isocyanate compounds present in the second component is a combined weight percentage ranging from about 20 percent, about 30 percent, or about 40 percent to about 70 percent, about 80 percent, about 90 percent, or about 100 percent, based on the total weight of the second component, or in weight percentages between any pair of the above values. foaming agent

[0035] The potting composition contains a blowing agent. A suitable blowing agent is one that can react with the residual components of the potting composition to create gas pockets within the potting composition, which form cavities when the potting compound hardens. Examples of chemical blowing agents include water, azodicarbonamide (for example, vinyl), hydrazine and other nitrogen-based materials for thermoplastic and elastomeric foams, and sodium bicarbonate for thermoplastic foams. In some embodiments, the blowing agent may be a gas. For example, the blowing agent may be a gas that is injected into the battery potting composition to create gas pockets within the potting composition when the components of the potting composition are mixed. Suitable blowing agents that can be injected into the battery potting composition include nitrogen or carbon dioxide.

[0036] In some embodiments, the blowing agent may be a liquid. In some embodiments, the blowing agent is water. For example, if the potting compound is formed from polyurethane, water may be included to react with the polyurethane-forming component when the polyurethane component is mixed to form carbon dioxide gas. The carbon dioxide gas forms bubbles in the liquid potting composition. The bubbles form cavities within the polyurethane after it has cured and hardened, resulting in a foam potting compound. In some embodiments, the blowing agent is present in the potting composition in a weight percentage of greater than 0, about 0.1 percent, about 0.5 percent, about 1.0 percent to about 1.5 percent, about 2.0 percent to about 2.5 percent, or about 3.0 percent, or any pair of the above values, based on the total weight of the first component. In some embodiments, the blowing agent may be contained in the first component. For example, in some embodiments, the blowing agent may be a liquid blowing agent contained in the first component. Flame retardant components

[0037] The potting composition contains a flame retardant component. The flame retardant component is preferably liquid at room temperature. In some embodiments, the potting composition contains two or more flame retardant components. The flame retardant component may be present in one or both of the first and second components. In some embodiments, the first component may contain a first flame retardant component, and the second component may contain a second flame retardant component.

[0038] Suitable flame retardant components may have viscosities of approximately 30 cP, 40 cP, 100 cP, 200 cP, 300 cP, or 400 cP to approximately 600 cP, 700 cP, 800 cP, 900 cP, or 2000 cP at room temperature (approximately 25°C to 35°C), or between any pair of the above values, but further liquid flame retardants with alternative viscosities may be conceived. Suitable liquid flame retardant components may have viscosities of approximately 300 cP or less at room temperature. For example, suitable liquid flame retardant components may have viscosities of approximately 40, 60, 80, or 100 to approximately 150, 200, 250, or 300 at room temperature, or between any pair of the above values, but further flame retardants with additional viscosities may be conceived.

[0039] In some embodiments, the flame retardant component includes a phosphate ester. The flame retardant component may include a halogenated phosphate ester. The flame retardant component may include either or both of a brominated phosphate ester or a chlorinated phosphate ester. For example, a suitable liquid flame retardant may be tris(2-chloroisopropyl)phosphate.

[0040] Other examples of flame retardant components include brominated diols, brominated monoalcohols, brominated ethers, brominated phosphoric acid, and brominated organic compounds including combinations thereof. Suitable brominated organic compounds include tetrabromobisphenol-A, hexabromocyclododecane, poly(pentabromobenzyl acrylate), pentabromobenzyl acrylate, tetrabromobisphenol A-bis(2,3-dibromopropyl ether), tribromophenol, dibromoneopentyl glycol, tribromoneopentyl alcohol, tris(tribromoneopentyl phosphate), and 4,4'-isopropylidenebis[2-(2,6-dibromophenoxy)ethanol].

[0041] In some embodiments, a suitable commercially available flame retardant component may be a chlorinated phosphate ester sold under the trade name FYROL PCF (from ICL Industrial Products, located in St. Louis, MO).

[0042] The flame retardant component is present in at least one of the first or second component. The flame retardant component may be present in at least one of the first or second component in weight percentages ranging from more than 0 percent, about 10 percent, about 20 percent, or about 30 percent to about 40 percent, about 50 percent, or about 60 percent, about 70 percent, or any pair of the above values, based on the total weight of the component in which the flame retardant component is present (either the first or second component). In some embodiments, the flame retardant component may be present in both the first and second components.

[0043] In some embodiments, the total amount of flame retardant components in the potting composition is, based on the total weight of the potting composition, about 15 percent, about 20 percent, about 25 percent, or about 30 percent by weight, to about 40 percent, about 45 percent, about 50 percent, about 55 percent, or about 60 percent by weight, or any pair of the above values ​​by weight. For example, the first flame retardant component may be present in the first component in about 30 percent, about 35 percent, or about 40 percent by weight, to about 45 percent, about 50 percent, or about 55 percent by weight, or any pair of the above values ​​by weight, based on the total weight of the first component, and the second flame retardant component may be present in the second component in about 20 percent, about 25 percent, or about 30 percent by weight, to about 35 percent, about 40 percent, or about 45 percent by weight, or any pair of the above values ​​by weight, based on the total weight of the second component.

[0044] In some cases, a suitable amount of flame retardant component in the potting composition has been found to provide a suitable level of flame retardancy without compromising other desired properties. For example, in some cases, the stiffness, hardness, flexibility, durability, or structural elasticity of a particular foam compound may be unsuitable in the presence of a high level of flame retardant. In some embodiments, a suitable weight percentage of flame retardant component in a polyurethane foam to provide a suitable level of flame retardancy and a sufficiently strong potting compound may be about 25 percent, about 30 percent, or at least about 35 percent, to about 40 percent, about 45 percent, or about 50 percent, based on the total weight of the potting composition. Any additional additives

[0045] The potting composition may optionally contain additional additives, either as separate components for forming the first and / or second component, or as a mixture of one or more of the components described above. Any additional additives may be present in the potting composition in weight percentages of greater than 0, about 0.1, about 0.5, or about 1, about 5, about 10, about 20 percent, or about 30 percent, or any pair of the above values, based on the total weight of the potting composition. The weight percentage of any additional additive may be applied to the whole combination of all additional additives present, or to each additional additive separately.

[0046] Some examples of additional additives that can be added to either or both of the first or second component include, but are not limited to, crosslinking agents, chain extenders, wetting agents, thixotropes, nucleating agents, surfactants, diluents, anti-settling agents, flame retardant enhancers, and components and combinations thereof. In some embodiments, optional additional additives include waxes, release agents, antioxidants, reinforcing fillers, dyes, heat stabilizers, UV stabilizers, plasticizers, rheological modifiers, processing aids, lubricants, release agents, or components or combinations thereof. Suitable reinforcing fillers include mineral fillers and glass fibers.

[0047] Further examples of additional components include catalysts. In the example of a polyurethane potting composition, any conventional catalyst known to those skilled in the art can be used to react the isocyanate compound with the isocyanate-reactive compound and residual components. Preferred catalysts include, but are not limited to, triol catalysts, tetrapolyol catalysts, or tertiary amine catalysts. Further examples of preferred catalysts include various alkylamines, alkyl ethers, or alkylthiol ethers, such as bismuth or tin, having 1 to about 20 carbon atoms in the alkyl moiety. Some examples include bismuth octanoate and bismuth laurate. Other catalysts include various tin catalysts such as stannous octanoate, dibutyltin dioctanoate, and dibutyltin dilaurate.

[0048] In the example of a polyurethane potting composition, the amount of catalyst present may be greater than 0, about 0.02, about 0.05, or about 0.1 to about 0.25, about 0.75, or about 1 percent, or any pair of weight percentages between the above values, based on the total weight of the battery potting composition. In some embodiments, a crosslinking agent or wetting agent may be present in the potting composition in greater than 0, about 0.1, about 0.5, or about 1 to about 1, about 5, about 7, or about 10 percent, or any pair of weight percentages between the above values. In some embodiments, a surfactant suitable for, for example, helping to stabilize or wet the foam structure may be present in the potting composition in greater than 0, about 0.1, about 0.5, or about 1 to about 2, about 3, or about 4 percent, or any pair of weight percentages between the above values, based on the total weight of the potting composition. In some embodiments, the nucleating agent may be present in the battery potting composition in a weight percentage of greater than 0, about 0.1, or about 0.5, about 1, about 1.5, or about 2 percent, or any pair of the above values, based on the total weight of the battery potting composition.

[0049] The first and second components are combined to form a potting composition having a flame retardant component. For example, in an embodiment of polyurethane used to form a foam potting composition, the first and second components are configured to form polyurethane. The polyurethane may be present in the potting composition in weight percentages ranging from about 30 percent, about 40 percent, or about 50 percent to about 60 percent, about 70 percent, or about 80 percent, or any pair of the above values, based on the total weight of the potting composition. In some cases, one technique for calculating the amount of polyurethane present in the potting composition is to use theoretical calculations based on the starting components. The weight percentages of all components that form polyurethane (if the starting components were for producing polyurethane with a yield of 100%) are summed up. Then, the sum of such components is taken as the weight percentage of the total amount of the potting composition to reach the weight percentage of polyurethane in the potting composition.

[0050] Any known process may be used to react the first component with the second component. In embodiments comprising a polyurethane potting composition, any known method may be used to combine the first and second components to produce a polyurethane foam. In some embodiments, the method for combining may be a "one-shot" process in which all reactants are mixed in a mixing vessel such as a bucket or reactor, reacted, and / or applied.

[0051] In some embodiments, the weight ratio of the isocyanate compound to the total equivalent weight of the isocyanate-reactive components may be a ratio between about 0.60, about 0.65, about 0.70, or about 0.75, about 0.80, about 0.85, about 0.90, or about 0.95, or any pair of the above values. In some embodiments, the ratio of the isocyanate compound to the isocyanate-reactive compound is selected so that an excess of reactive isocyanate equivalents is used relative to the total number of isocyanate reactive groups on the isocyanate-reactive compound.

[0052] In some embodiments, the first component polyol may be present in the potting composition in weight percentages ranging from about 10 percent, about 20 percent, about 30 percent, about 40 percent to about 50 percent, about 60 percent, about 70 percent, or about 80 percent, or any pair of the above values.

[0053] Figure 1 is a perspective view of an exemplary battery module 10. As shown in Figure 1, the battery module 10 includes an electrical cell 20 and a battery case 22. In some embodiments, the electrical cell 20 may be positioned within the battery case 22 and potted within a potting compound 24. The electrical cell 20 may be any suitable shape, generally having a bottom 30, a top 32, and a defined length between them. The battery case 22 may be any suitable shape for holding the electrical cell 20, generally having a bottom 36, a top 38, and a wall 40 defined between them. The bottom 36 of the battery case 22 defines an inner and outer surface, and the wall 40 of the battery case defines an inner and outer surface. The battery case 22 defines a sealed space having an internal volume. The potting compound 24 is positioned within the battery case 22 and occupies a portion of the internal volume of the battery case 22. The potting compound 24 generally has a top 42, a bottom 44, and a defined height between them.

[0054] Figure 2 is a top view of the battery module 10 shown in Figure 1. As shown in Figure 2, the battery case 22 forms a sealed space large enough to enclose the electrical cell 20 and other components such as wires or connectors. The sealed space defines the internal volume of the battery case 22. The bottom 36 of the battery case 22 can be closed and can also contain any contents of the sealed space. The top 38 of the battery case 22 can define an opening. The top 38 and / or opening may be molded and sized to receive a cover, which can be closed to isolate the internal volume of the sealed space from the outside of the battery case 22. The cover may be configured to seal the internal volume of the sealed space from the outside of the battery case 22 to prevent the ingress of potential hazards such as fluids or flames. The battery case 22 may be designed and configured to provide mechanical or structural support to the electrical cell 20. The battery case 22 may also be configured to provide protection from moisture, heat, cold, or any other potential factors that could damage the electrical cell 20.

[0055] As shown, in one possible arrangement, the electric cell 20 may be formed as a cylinder. In further embodiments, the electric cell 20 may be formed into any suitable shape or size, such as a cube, sphere, or pyramid, as needed. The electric cell shown in Figure 1 is formed as a cylinder having a bottom 30, a top 32, and a wall extending between the bottom 30 and the top 32. The bottom 30 may be the anode terminal or the negative terminal of the electric cell 20, depending on the desired orientation. As shown, the bottom 30 of the electric cell 20 is positioned within a potting compound 24. The potting compound 24 occupies a portion of the internal volume of the battery case 22 and extends substantially equally at various points along the wall 40 from the bottom 36 to the top 38 of the battery case 22.

[0056] Electrical cells can be used to form batteries. For example, multiple electrical cells can be combined to form a single battery with a higher voltage or amperage than a single electrical cell.

[0057] Figure 3 is a front view of a battery module 50 including electrical cells 52. Each electrical cell 52 has a bottom 60, a top 62, and a wall between them that defines their length. The electrical cells 52 can be positioned within a battery case 54. The electrical cells 52 define a gap 80 between each electrical cell and adjacent electrical cells. The gap 80 has a width. The battery case 54 has a bottom 66, a top 68, and a wall 70 between them. The bottom 66 and the wall 70 define a sealed space. The sealed space of the battery case 54 defines an internal volume. The internal volume of the battery case 54 has a suitable volume for receiving the electrical cells 52 and the potting compound 56. The potting compound 56 has a bottom 82, a top 84, and a height 86 between them. The bottom 82 of the potting compound 56 is adjacent to the inner surface of the bottom 66 of the battery case 54. As shown, the top 84 of the potting compound 56 is located between the bottom 66 and top 68 of the battery case 54. Typically, the top 84 of the potting compound 56 is lower than the top 62 of the electric cell 52, but in alternative arrangements, the top 62 of the electric cell 52 may be lower than the top 84 of the potting compound 56.

[0058] As shown, multiple electrical cells 52 can be arranged in close proximity to each other, and each electrical cell 52 is oriented with its similarly charged terminals facing the same direction. Wires can be attached to the ends of the electrical cells 52. The wires can be combined in telecommunications to combine the currents from the electrical cells 52 to form a battery having, for example, a combined current or voltage. The battery module 50 can be used to power any of several applications, such as household appliances, outdoor electrical equipment, or vehicles such as automobiles or boats.

[0059] To combine the electrical cells 52 to form a battery, the electrical cells 52 are connected to wires that conduct current from the electrical cells 52. The electrical cells 52 are often arranged adjacent to each other, for example in rows or stacked, to form a regular arrangement for ease of use and / or for connecting wires to the electrical cell terminals. To save space and to form a compact battery, the electrical cells 52 may be positioned adjacent to each other. For example, the electrical cells 52 may be arranged in rows or as a grid, with the positive and negative terminals oriented in the same direction. The electrical cells 52 may be positioned in a regular arrangement and contained within a battery case 54, but in some embodiments, it is assumed that a battery module may be formed without a battery case 54. For example, the electrical cells 52 may be bundled and held together using alternative fasteners such as wires, strings, or bands.

[0060] In some cases, as an example, it may be desirable to have a portable battery, such as a battery for starting the ignition of a vehicle such as a motorcycle, automobile, or boat, or for powering them. When portability is desirable for a battery, it is typically preferable to provide a battery that is structurally stable and can withstand forces such as shock and / or vibration. Also in some cases, it is desirable to provide a battery that can withstand extreme temperatures, including temperatures other than the normal operating temperature of the battery. For example, in some cases, a battery may be subjected to high temperatures and may produce a flame. One possible source of flame may be one or more electrical cells, for example, as a result of an electrical short circuit or when the structure of the electrical cell wall is compromised. One exemplary device that may be used to protect the electrical cell 52 is a potting compound 56. The potting compound 56 may be associated with the electrical cell 52, such as being positioned around the electrical cell 52 along the top, bottom, or one or more of the walls of the electrical cell. One or more electrical cells 52 can be housed or embedded within the potting compound 56, which holds the electrical cells 52 in spatial relation to each other and / or in spatial relation to the battery case 54.

[0061] As shown in Figure 3, the electrical cells 52 are positioned within the potting compound 56. The potting compound 56 is positioned around each of the electrical cells 52. If the battery contains multiple electrical cells 52, the potting compound 56 may be positioned around each electrical cell and within the gaps 80 or spaces defined between the individual electrical cells 52. If the battery is contained within a battery case 54, the potting compound 56 may be positioned between one or more electrical cells 52 and the battery case 54. The potting compound 56 may be positioned to provide suitable structural or mechanical support to the electrical cells 52.

[0062] In some cases, the electrical cells 52 may be positioned with a suitable distance between adjacent electrical cells 52 so that individual electrical cells 52 are thermally and / or fluidly isolated from each other in the event of leakage or fire. In some cases, the electrical cells 52 may be positioned with a suitable distance between adjacent electrical cells 52 so that a suitable thickness of potting compound 56 is positioned between adjacent electrical cells 52 to provide sufficient shock absorption and prevent damage to the electrical cells 52. The size of the space or gap 80 between adjacent electrical cells 52 and / or battery case 54 can be selected based on several variables, including, but not limited to, the size and / or weight of each electrical cell, the operating temperature of each electrical cell, the dimensions of each electrical cell, and the intended use of the battery module 50. In some embodiments, the size of the space between adjacent electrical cells may range from over 0 mm, about 0.25 mm, about 0.50 mm, about 0.75 mm, about 1.0 mm, about 1.5 mm, or about 2.0 mm, or any pair between the above values, but battery modules with additional configurations can be further conceived. In some embodiments, the size of the space between the electrical cell and the battery case may range from over 0 mm, about 1.0 mm, about 2.0 mm, about 3.0 mm, about 10 mm, about 12 mm, or about 14 mm, but battery modules with additional configurations can be further conceived.

[0063] In some embodiments, the potting compound 56 can be formed by first molding a material, such as a potting composition, into a suitable shape having spaces defined by the potting compound 56 for holding one or more electric cells 52. The potting compound 56 can be formed by molding a potting composition having a size and shape such that the potting compound 56 is positioned within the battery case 54, and defining one or more spaces for holding one or more electric cells 52 positioned within those spaces.

[0064] In some embodiments, the potting compound 56 can be formed by first positioning the electric cells 52 in a desired final position, for example, together with wires or held within a battery case 54. The electric cells 52 can be held in place in spatial relationships with each other using a mold or scaffolding. The electric cells 52 can be held and positioned in place within a mold or other case surrounding the electric cells 52. In further embodiments, the electric cells 52 can be positioned in a desired final position in spatial relationships with each other and placed within the battery case 54, for example, by resting on the inner surface of the bottom 66 of the battery case 54. Once the desired positioning of the electric cells 52 is achieved, the potting compound 56 can be formed by flowing the potting composition around the electric cells 52 and through the gaps 80 or spaces defined between adjacent electric cells 52. The potting composition can be applied as a liquid so that it flows between adjacent electric cells 52 and through the gaps 80 defined between the electric cells 52 and the wall 70 of the battery case 54. As described above, the potting composition may be configured to be applied as a liquid that hardens into a solid after application, forming a potting compound 56. In some embodiments, the potting composition may be reactive such that the potting composition flows around the electric cell 52 and through the voids 80 defined between adjacent electric cells 52, and is then applied as a liquid that hardens after the reaction is complete.

[0065] The potting composition can flow through the gaps 80 between adjacent electrical cells 52 and stabilize at a horizontal height around the electrical cells 52 and within the gaps 80 or spaces defined between the electrical cells 52. For example, referring to Figure 3, the potting composition can be injected into a battery case 54 in which the electrical cells 52 are disposed. The liquid potting composition has sufficient fluidity before curing to allow the liquid potting composition to flow through the spaces defined by the gaps 80 between adjacent electrical cells 52 and / or between the electrical cells and the battery case 54. The liquid potting composition has sufficient fluidity before curing to stabilize at a substantially horizontal height in order to form a potting compound.

[0066] As used herein, fluidity refers to the ease with which a substance moves under a specific set of conditions. Some of these conditions include the temperature of the substance, its viscosity, or the size of the space through which the substance can flow. For example, in the case of a potting composition that is a liquid, the fluidity of the liquid determines how the liquid behaves when injected and how well it flows between adjacent electrical cells and / or between electrical cells and the battery case.

[0067] In a preferred embodiment, the potting composition has sufficient fluidity to allow it to be injected around the electric cell or electric cell 52 and stabilized at a substantially horizontal height around the electric cell or electric cell 52 before the potting composition hardens to form the potting compound 56. That is, the potting composition has sufficient fluidity to disperse to a height of 86, and this height is substantially the same at various locations around the electric cell 52 (e.g., throughout the battery case 54) before the potting composition hardens to form the potting compound.

[0068] In some embodiments, to determine a substantially horizontal height, the height 86 of the potting compound 56 can be measured from the bottom 82 of the potting compound to the top 84 of the potting compound 56. This height can be measured toward the center of the battery case 54 at various locations throughout the potting compound 56, such as equidistant from two opposing sides of the case (e.g., near the walls of the battery case 54). As used herein, substantially horizontal height means that the measured height 86 of the potting compound at various locations are within 20 percent of each other.

[0069] In some cases, the test for determining the substantially horizontal height of the potting compound 56 may be as follows: With respect to a battery such as a battery module 50 having adjacent electrical cells 52, if the electrical cells 52 are of the same length and are located at the same distance from the bottom and / or top of the battery case 54, the potting compound is substantially horizontal if it is at approximately the same distance along each of the lengths of the electrical cells 52. As used herein, approximately the same distance is defined as each distance measurement being within 20 percent of the other. In some cases, this test can be used to determine the substantially horizontal height of the potting compound 56 when the average size of each gap 80 between adjacent electrical cells 52 is, for example, about 1 mm to about 3 mm in width.

[0070] Having a potting composition with sufficient fluidity to form a substantially horizontal height forms a potting compound that encloses each of the electrical cells at substantially the same height. This provides a consistent amount of enclosure around each of the electrical cells. This can ensure that the suitable enclosure of the electrical cells 52 ensures a suitable level of protection, such as a suitable amount of structural stability and / or a suitable amount of flame retardant to contain fire or flames. Having a potting compound with a substantially horizontal height can help balance the weight of the battery module 50 throughout the battery module 50. A suitable balance or weight distribution helps maintain a stable state of the battery module 50, for example, when used in a moving vehicle. A well-balanced battery module may be less prone to swaying or tilting in response to external forces such as left-right, front-back, or acceleration, and may therefore be preferred for use in vehicles.

[0071] Having a lighter battery module can be preferable because it can make the battery module more portable and reduce the amount of energy required to move it. For example, in an electric vehicle, it may be advantageous to have a lighter battery module that can produce the same amount of power as a heavier embodiment. One option to achieve this may be to use the same type and number of electrical cells but reduce the weight of other components. Reducing the density of the potting compound can help reduce the overall weight of the potting compound without compromising other desired qualities. Also, having a flame retardant component helps reduce the possibility of uncontrolled fires from the battery module.

[0072] After complete curing, the potting compound will have some degree of elasticity, thereby mitigating shocks or vibrations applied to the battery module during use. This can help prevent safety issues arising from collisions between electrical cells and / or from electrical cells being detached from wires.

[0073] The cured potting compound can have a certain degree of porosity, and to enhance the safety performance of the battery module, if one electrical cell is involved in a safety issue or leakage, the leaking material, such as fluid or gas, is controlled to be contained and isolated by the potting compound positioned between adjacent electrical cells. In addition, the battery module has advantages such as a simple structure, low density, small size, and low cost.

[0074] Disclosed are potting compounds that are low in density, contain a flame retardant, and are in the form of a foam. The potting compounds are suitable for use in forming battery modules. Also disclosed are potting compositions that have suitable fluidity for forming a potting compound that has substantially horizontal height throughout the battery module.

[0075] Figure 4 is a perspective view of an exemplary battery module 100. As shown in Figure 4, the battery module 100 includes an electrical cell 120 and a battery case 122. In some embodiments, the battery module 100 includes more than one electrical cell 120. The electrical cell 120 can be any suitable shape, generally having a bottom 130, a top 132, and a defined length between them. The battery case 122 can be any suitable shape for positioning the electrical cell 120 within the battery case 122. The battery case 122 can be any preferred three-dimensional shape, generally having a bottom 136, a top 138, and a wall 140 defined between them. The bottom 136 of the battery case 122 defines an inner and outer surface, and the wall 140 of the battery case 122 defines an inner and outer surface. The battery case 122 defines a sealed space having an internal volume.

[0076] As shown, the electric cell 120 may be positioned within the battery case 122. Also as shown, the electric cell 120 is associated with the potting compound 124. The potting compound 124 is positioned within the battery case 122 and occupies a portion of the internal volume of the battery case 122.

[0077] In some embodiments, the battery case 122 forms a sealed space surrounding the electrical cell 120 and other components such as wires, terminals, or connectors. The sealed space defines the internal volume of the battery case 122. The top 138 of the battery case 122 may define an opening. The top 138 may be molded and sized to receive a cover, which can be closed to isolate the internal volume of the sealed space from the outside of the battery case 122. The battery case 122 may be configured to provide mechanical or structural support to the electrical cell 120. The battery case 122 may be configured to provide protection to the electrical cell 120 from potential damage, such as moisture, heat, cold, chemicals, shock, vibration, puncture, or flame. In some embodiments, the battery case 122 may be configured to receive the potting compound 124 relative to the electric cells 120, for example, on the underside of the electric cells 120, between the first and adjacent electric cells 120, on the upper side of the electric cells 120, or between the electric cells 120 and the wall 140 of the battery case.

[0078] In some embodiments, a method for positioning the potting compound 124 relative to the electric cell 120 includes first positioning the electric cell 120 inside the battery case 122. One or more electric cells 120 may be positioned together within the battery case having a defined gap 180 between adjacent electric cells 120. In some embodiments, the gap 180 may be defined between the electric cell 120 and the wall 140 of the battery case 122. In some embodiments, the potting compound 124 may be prepared in a separate container and then injected into the battery case 122. For example, the components of the potting compound 124 may be mixed to form a composition that can be cured to form a foam, and then the foam may be applied to the top 132 of the electric cell 120. The potting compound 124 may be added so that a layer of potting compound 124 having thickness is placed on top of the top 132 of the electric cell 120. In some embodiments, the potting compound 124 may be positioned within the gap 180 between adjacent electric cells 120. The potting compound 124 can be positioned within the gap 180 between the wall 120 and the electric cell 120. The potting compound 124 can be positioned such that a space is defined between the top of the potting compound 124 and the top 138 of the battery case 122. In some embodiments, a certain amount of potting compound 124 can be cured into a preferred pre-formed shape, which can then be added into the battery case 122 at a preferred position relative to the electric cell 120.

[0079] Figure 5 is a top view of an exemplary battery module 200. The battery module 200 includes electrical cells 220 positioned adjacent to each other. As shown in Figure 5, the electrical cells 220 are positioned within a battery case 222 having a top 238. The battery case 222 defines an internal volume. As shown, the battery case 222 is sized so that the electrical cells 222 can be positioned within the internal volume of the battery case 222, with space between the top 232 of the battery case 222 and the top 232 of the electrical cells 220. Also shown is a potting compound 224 positioned within the internal volume of the battery case 222. As shown, the potting compound 224 has a substantially planar shape and extends along the top 232 of the electrical cells 220. The potting compound 224 can be configured to make the terminals 290 of the electrical cells 220 accessible to the user. In some embodiments, the electric cell 220 includes terminals 290 positioned on the top 232 of the electric cell 220. The potting compound 224 can be positioned around the terminals 290 and between the top 232 of the electric cell 220 and the top 238 of the battery case 222.

[0080] In some embodiments, a method for positioning the potting compound 224 relative to the electric cell 220 includes first positioning the electric cell 220 inside the battery case 222. The potting compound 224 can be prepared in a separate container and then injected into the battery case 222. A suitable amount of potting compound 224 can be added so that a layer of potting compound 224 having thickness is positioned on the top 232 of the electric cell 220 or between at least one adjacent electric cell 220. In some embodiments, the potting compound 224 can be added so that the layer of potting compound 224 has a suitable thickness to cover the top 232 of the electric cell 220, with the terminals 290 protruding through the thickness of the potting compound 224. The potting compound can maintain the electric cells 220 in a spatial relationship with each other by holding the electric cells 220 relative to each other, for example by potting or sealing the terminals 290.

[0081] Figure 6 is an exploded view of an exemplary battery module 300. The battery module 300 includes electrical cells 320 positioned adjacent to each other. In some embodiments, the battery module 300 includes a battery case 322. The electrical cells 220 are shown with their terminals 290 positioned on the top 232 of the electrical cell 220. Also shown is a potting compound 324 associated with the electrical cells 320. As shown in Figure 6, the electrical cells 320 can generally have a planar shape. As shown, the compartments of the potting compound 224 can generally have a planar shape. In some configurations, the compartments of the potting compound 324 can be positioned between adjacent electrical cells 320. For example, the compartments of the potting compound 324 can have a planar shape and can also be positioned parallel to the plane of the electrical cells 320.

[0082] In some embodiments, a method for positioning a potting compound 324 relative to an electrical cell 320 includes first positioning the electrical cells 320 in a spatial relationship with respect to each other, and then positioning the potting compound 324 in a defined space between adjacent electrical cells 320. For example, the potting compound 324 can be injected into the space between adjacent electrical cells 320 and cured. In a further embodiment, the potting compound 324 can be cured and formed in a pre-formed compartment, and then positioned in the space between adjacent electrical cells 320. A suitable amount of potting compound 324 can be provided so that a compartment of potting compound 324 having a suitable thickness is positioned between adjacent electrical cells 220. In some embodiments, a compartment of potting compound 224 can be provided so that the compartment of potting compound 324 has a suitable thickness to provide a suitable level of flame resistance. In some embodiments, the potting compound 320 can maintain the spatial relationship between the electrical cells 320, for example, to absorb shocks or vibrations of the battery module 300. [Examples]

[0083] The following non-limiting embodiments are included to further illustrate the various embodiments of the Disclosure and do not limit the scope of the Disclosure. Test method: Viscosity test

[0084] Viscosity is measured using a Brookfield viscometer model RVF (from AMETEK Brookfield, Middleboro, Massachusetts) at a spindle speed of 20 rpm and a temperature of 25°C (77°±2°F). The spindle used depends on the composition being tested and is either number 1 (maximum 500 cps), number 2 (maximum 2000 cps), or number 5 (maximum 20,000 cps). Measuring foam concentration

[0085] The weight of the empty measuring device, specifically the measuring cup, was recorded as being within 0.1 grams. The maximum volume of the measuring device was determined by filling the device with water and recording the amount of water required to fill its internal volume in milliliters. Various components were weighed and added to the measuring device.

[0086] The ingredients for generating the foam were vigorously mixed for 15-20 seconds. The sides and bottom of the measuring device were thoroughly scraped to ensure that all ingredients reacted. The liquid was leveled by vigorously tapping the measuring device lightly against a hard surface. The measuring device was placed on a horizontal surface and allowed to stand freely without obstructing the foam. The foam was allowed to cure and cool for 60-70 minutes. After curing, the top of the foam bun was cut horizontally to the top of the measuring device using a flat tool, in this case a knife or saw.

[0087] The measuring device, including the remaining foam, was weighed, and its weight was recorded in grams. The weight of the foam was obtained by subtracting the weight of the empty measuring device from the weight of the measuring device including the remaining foam. The density was calculated by dividing the weight of the foam by the volume of the measuring device. Fluidity test

[0088] The composition to be tested was mixed by manual mixing with a stirring time of 20 to 25 seconds. Then, a sample of 65 to 70 grams of the composition to be tested was poured into one side of a container measuring 8 cm × 15 cm × 9 cm, in which 26 18650 type cylindrical battery cells were placed upright. The test was carried out at an ambient temperature of 21°C to 24°C (approximately 70°F to approximately 75°F).

[0089] The composition was observed visually as it flowed between cylindrical battery cells. The level of stability of the composition upon curing was evaluated as "unacceptable," "acceptable," "good," or "very good," depending on how well the composition cured at a uniform planar height around the battery cells. "Very good" corresponds to a height around the battery cells where the variation at the test position in the container is less than 10%. Combustion test

[0090] The combustion test was conducted according to the UL94 "Flammable Test for Plastics" and "Vertical Burning Test" methods. Combustion test rods were prepared in molds with dimensions of 125–152 mm in length, 13 mm in width, and 9.5 mm or 6.35 mm in thickness. The foam was cured in the mold for 8–12 hours before removal. After molding, the rods were pre-conditioned at 25±2°C and 50±5% RH for a minimum of 48 hours prior to the test.

[0091] For a set of five test specimens, a V-0 rating was given if the flame on each specimen extinguished within 10 seconds after removal from the burner flame, the total time after burning was within 50 seconds, and there was no ignition of the cotton indicator. A V-1 and V-2 rating was given if, for a set of five test specimens, the flame on each specimen extinguished within 30 seconds after removal from the burner flame, and the total time after burning was within 250 seconds. A V-2 rating was given if the cotton indicator was allowed to ignite due to flame particles.

[0092] An exemplary method for forming potting compounds is described. This same process is used for all sample potting compounds, and the amounts of each component are listed in Table 1 below. Formation process of the first and second components

[0093] To form the first component, liquid polyethertriol was first added to the mixing vessel. Mixing was started while adding the liquid polyethertriol to the mixing vessel. The mixer speed was 25-30 rpm when adding the liquid polyethertriol. Once all of the liquid polyethertriol had been added, the mixer speed was increased to 600-800 rpm.

[0094] Next, liquid glycerin, triethanolamine, polyether, and a settling inhibitor were added to the sample containing these substances in a mixing container. Then, thixotrop (fumed silica), a nucleating agent, a brominated flame retardant component, and a flame retardant enhancer (antimony trioxide) were added to the sample containing these substances in a mixing container. The contents of the mixing container were mixed for approximately 15 to 20 minutes.

[0095] Next, distilled water was added to the mixing container. While mixing the contents of the mixing container with the sample containing these substances, the tertiary amine catalyst and surfactant were added. Then, the phosphate ester flame retardant was added. The contents of the mixing container were mixed for about 30 minutes to form the first component. After about 30 minutes, mixing was stopped, and the first component was drained from the mixing container and the container was emptied.

[0096] To form the second component, liquid isocyanate was added to the mixing container. The liquid isocyanate was added to the mixing container while mixing at a mixer speed of 25-30 rpm. Next, in the sample containing the flame retardant included in the second component, a phosphate ester flame retardant was added to the mixing container. The contents of the mixing container were mixed for 15-20 minutes to form the second component. After 15-20 minutes, mixing was stopped and the second component was removed from the mixing container and emptied. Potting composition and potting compound formation process

[0097] The first and second components were poured into a mixing container in a suitable ratio. The mixing container used was larger than the total volume of the materials being mixed to allow for vigorous mixing. For example, if the total volume of materials is 75 grams, the minimum size of the proposed container is a 150 mL mixing container.

[0098] The component with the higher concentration was added to the mixing vessel first, and then the second component was slowly added on top of the first component. This helped to limit the pre-reaction of the materials to a simple reaction at the interface. The sides and bottoms of each measuring container were scraped to ensure that almost all of the measuring material was added to the mixing vessel.

[0099] The timer was started, and the contents of the mixing container were vigorously mixed for 20-30 seconds using a flat-surface stirring tool until the material was visible and uniform. During mixing, the sides and bottom of the mixing container were scraped. After mixing, the contents of the mixing container were immediately poured into the mold.

[0100] To form the non-flammable sample, substantially the same steps as those described for the flame-retardant material were used. However, the flame retardant was added to either the first or second component.

[0101] Comparative examples and samples 1-10 were prepared with the following components, as provided by trade names and available suppliers, and in the amounts listed in Table 1: 2000M nPPG diol polyether polyol (low viscosity polyol - EO cap) (Poly G 55-56, available from Monument Chemical Group in Houston, TX); 99.5% glycerin (triol crosslinking agent / wetting agent) (available from Dow Chemical Company in Midland, MI); 99% triethianol (triol crosslinking agent / wetting agent / catalyst) (available from Dow Chemical Company in Midland, MI); fumed silica (thixotrop) (AEROSIL200, available from Evonik Industries in Essen, Germany); zinc stearate (nucleating agent) (NB-60, available from PMC Group in Memphis, TN); zinc borate (flame retardant) (ZB-467, available from Lanxess Aktiengesellschaft in Cologne, Germany). Ethylene bistetrabromophthalimide (brominated flame retardant) (SAYTEX BT-93, available from Albemarle Corporation in Baton Rouge, LA); distilled water (foaming agent); 1,4-diazabicyclo[2.2.2]octane solution (tertiary amine catalyst) (DABCO 33LV, available from Evonik Industries in Essen, Germany); titanium dioxide (coloring agent / nucleating agent); tertiary amine catalyst (DABCO 8154, available from Evonik Industries in Essen, Germany); 700M n PPG triol polyol (low viscosity polyol) (Poly-G 30-240, available from Monument Chemical Group in Houston, TX); 700M n Polyether polyol (polypropylene oxide-based triol) (ARCOL LHT-240, available from Covestro in Leverkusen, Germany); tetrafunctional polyether polyol (Poly-Q 40-800E, available from Arch Chemicals, Inc. in Norwalk, CT); 280M nAmine / PPG tetrapolyol (tetracrosslinking agent / wetting agent / catalyst) (VORANOL 800, available from The Dow Chemical Company in Midland, MI); polyether polyol (VORANOL 230-238, available from The Dow Chemical Company in Midland, MI); silicone surfactant (foam cell surfactant) (VORASURF DC5160, available from Dow Chemical Company); halogenated phosphate ester (flame retardant) (FYROL PCF, available from ICL Industrial Products in St. Louis, MO); trimethylpentanyl diisobutyrate (viscosity diluent) (EASTMAN TXIB, available from Eastman Chemical Company in Kingsport, TN); phosphate ester (flame retardant) (FYROL A710, available from ICL Industrial Products in St. Louis, MO); isopropylated triaryl phosphate ester (phosphorus-based flame retardant) (REOFOS, available from Lanxess Aktiengesellschaft in Cologne, Germany) 35); Cresyl diphenyl phosphate (flame retardant) (KRONITEX CDP, available from Lanxess Aktiengesellschaft in Cologne, Germany); Antimony trioxide (flame retardant performance enhancer) (AMSPEC SELECT, available from Amspec Chemical Corporation in Gloucester City, NJ); Modified urea solution (rheological additive / precipitation inhibitor) (BYK-410, available from BYK USA Inc. in Wallingford, CT); Modified liquid MDI (isocyanate - 29% NCO) (ISONATE 143L, available from Dow Chemical Company in Midland, MI); Polymeric MDI (functional value 2.7) (RUBINATE M, available from Huntsman Corporation in Woodlands, TX).

[0102] The compositions were prepared and tested according to the test methods described above. The results and findings are shown in Table 1.

[0103] [Table 1]

[0104] [Table 2]

[0105] [Table 3]

[0106] Samples 11-14 were prepared using a process similar to that described for samples 1-10. Samples 11-14 were prepared with the following components, as provided by trade name and available supplier, and in the quantities listed in Table 2: 99.5% glycerin (triol crosslinking agent / wetting agent) (available from Dow Chemical Company in Midland, MI); 99% triethianol (triol crosslinking agent / wetting agent / catalyst) (available from Dow Chemical Company in Midland, MI); fumed silica (thixotrop) (TS-720 available from Cabot Corp. in Boston, MA); zinc stearate (nucleating agent) (NB-60 available from PMC Group in Memphis, TN); ethylene bistetrabromophthalimide (brominated flame retardant) (SAYTEX BT-93 available from Albemarle Corporation in Baton Rouge, LA); distilled water (foaming agent); 1,4-diazabicyclo[2.2.2]octane solution ((primary) tertiary amine catalyst) (Evonik in Essen, Germany) DABCO 33LV (available from Industries); (secondary) tertiary amine catalyst (DABCO DMDEE available from Evonik Industries in Essen, Germany); 700M nPPG triol polyol (low viscosity polyol) (Poly-G 30-240, available from Monument Chemical Group in Houston, TX); 280M n Amine / PPG tetrapolyol (tetracrosslinking agent / wetting agent / catalyst) (VORANOL 800, available from The Dow Chemical Company in Midland, MI); silicone surfactant (foam cell surfactant) (VORASURF DC5160, available from The Dow Chemical Company); halogenated phosphate ester (flame retardant) (FYROL PCF, available from ICL Industrial Products in St. Louis, MO); silicone surfactant (EPH190, available from Evonik Industries); diamine (curing agent) (LONZACURE DETDA80, available from Lonza, Inc. in Allendale, NJ); antimony trioxide (flame retardant performance enhancer) (AMSPEC SELECT, available from Amspec Chemical Corporation in Gloucester City, NJ); modified urea solution (rheological additive / sedimentation inhibitor) (BYK USA, available from Wallingford, CT) BYK-410 / BYK-430 available from Inc.; fumed silica (TS-720); polymeric MDI (functional value 2.7) (RUBINATE M available from Huntsman Corporation in Woodlands, TX); halogenated phosphate ester (FYROL PCF); silicone surfactant (VORASUF DC5098 available from Dow Chemical Company).

[0107] The compositions were prepared and tested according to the test methods described above. The results and findings are shown in Table 2.

[0108] [Table 4]

[0109] Various modifications and additions may be made to the exemplary embodiments discussed without departing from the scope of the invention. For example, while the embodiments described above refer to specific features, the scope of the invention also includes embodiments having different combinations of features and embodiments that do not include all of the features described above.

Claims

1. The liquid potting composition is positioned in the space defined between the side of the first electric cell positioned within the container, the side of the second electric cell, and at least one of the sides of the container. The liquid potting composition is allowed to flow substantially horizontally within the container, A method for potting an electric cell, comprising curing the potting composition to form a potting compound, The liquid potting composition Isocyanate-reactive compounds; Foaming agent; Isocyanate compounds; and Liquid flame retardant component exceeding 15% by weight A method for potting electric cells, including the following.

2. The method for potting an electric cell according to claim 1, wherein the liquid potting composition contains more than 20% by weight of the liquid flame retardant component.

3. The method for potting an electric cell according to claim 1, wherein the liquid potting composition contains more than 30% by weight of the liquid flame retardant component.

4. The method for potting an electric cell according to claim 1, wherein the potting compound is a polyurethane foam potting compound having at least V2 level flame resistance when measured by UL94 "Plastics Material Flammability Test" using a test piece with a width of 13 mm and a thickness of 9.5 mm.

5. The method for potting an electric cell according to claim 1, wherein the potting compound is a polyurethane foam potting compound that has at least V0 level flame resistance when measured by UL94 "Plastics Material Flammability Test" using a test piece with a width of 13 mm and a thickness of 9.5 mm.

6. The potting compound is 0.60 g / cm³ ３ A method for potting an electric cell according to claim 1, wherein the polyurethane foam potting compound has a density of less than 100%.

7. The method for potting an electric cell according to claim 1, wherein the liquid flame retardant component exhibits a viscosity of 30 cP to 2000 cP at a temperature of approximately 25°C to approximately 35°C.

8. The method for potting an electric cell according to claim 1, wherein the liquid potting composition contains more than 15% by weight of a liquid phosphate ester.

9. The method for potting an electric cell according to claim 1, wherein the liquid potting composition contains more than 15% by weight of a liquid halogenated phosphate ester.

10. At all temperatures from 25°C to 35°C, The isocyanate-reactive compound exhibits a viscosity greater than 1 cP and less than 800 cP. The isocyanate compound exhibits a viscosity greater than 1 cP and less than 1000 cP. The method for potting an electric cell according to claim 1, wherein the liquid flame retardant component exhibits a viscosity of 30 cP to 300 cP.

11. A method for potting an electrocell, comprising positioning a liquid potting composition in a sealed space defined by the walls of a container containing at least an electrocell, The liquid potting composition A first component comprising an isocyanate-reactive compound and a foaming agent; Second component containing an isocyanate compound Includes, At least one of the first and second components contains 15% by mass or more of a flame retardant component based on the total weight of the liquid potting composition. (a) The first component has a viscosity of more than 1 cP and less than 1500 cP at 25°C. (b) The second component has a viscosity of more than 1 cP and less than 1000 cP at 25°C. A method for potting an electric cell, relating to at least one of the following.

12. A method for potting an electric cell according to claim 11, further comprising flowing the liquid potting composition in the container to a substantially horizontal height before the formation of the potting compound.

13. The potting compound is 0.60 g / cm³ ３ A method for potting an electric cell according to claim 11, wherein the polyurethane foam potting compound has a density of less than 100%.

14. At all temperatures from 25°C to 35°C The first component has a viscosity greater than 1 cP and less than 1500 cP. The method for potting an electric cell according to claim 11, wherein the second component has a viscosity of more than 1 cP and less than 1000 cP.

15. The method for potting an electric cell according to claim 11, wherein the liquid potting composition contains more than 20% by weight of the flame retardant component.

16. The method for potting an electric cell according to claim 11, wherein the liquid potting composition contains more than 30% by weight of the flame retardant component.

17. The method for potting an electric cell according to claim 11, wherein the flame retardant component exhibits a viscosity of 30 cP to 2000 cP at a temperature of approximately 25°C to approximately 35°C.

18. The method for potting an electric cell according to claim 11, wherein the flame retardant component comprises a liquid phosphate ester in an amount of more than 15% by weight.

19. The method for potting an electric cell according to claim 11, wherein the flame retardant component comprises a liquid halogenated phosphate ester in an amount of more than 15% by weight.

20. A method for potting an electrocellular cell, comprising positioning a liquid potting composition in a space defined between the side of a first electrocellular cell positioned within a container, the side of a second electrocellular cell, and at least one of the sides of the container, The liquid potting composition is Before forming a polyurethane foam potting compound that exhibits at least V2 level flame resistance when measured by UL94 "Plastics Flammability Test" using a test specimen with a width of 13 mm and a thickness of 9.5 mm, A method for potting an electric cell, having sufficient fluidity to flow substantially horizontally within the space.

21. The method for potting an electric cell according to claim 20, wherein the potting compound is a polyurethane foam potting compound that has at least V0 level flame resistance when measured by UL94 "Plastics Material Flammability Test" using a test piece with a width of 13 mm and a thickness of 9.5 mm.

22. The potting compound is 0.60 g / cm³ ３ A method for potting an electric cell according to claim 20, wherein the polyurethane foam potting compound has a density of less than 100%.

23. The method for potting an electric cell according to claim 20, wherein the liquid potting composition contains more than 15% by weight of liquid phosphate ester.

24. The method for potting an electric cell according to claim 20, wherein the liquid potting composition contains more than 15% by weight of a liquid halogenated phosphate ester.

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