HK40015942A - Electric cell potting compound and method of making - Google Patents

Description

Cell potting compound and method for producing same

Technical Field

The present disclosure relates to battery modules (battery modules) including battery cells (electric cells) disposed in a potting compound. More particularly, the present disclosure relates to battery modules including battery cells disposed in a flame retardant-containing foam potting compound.

Background

Generally, potting is the process of partially or completely filling or embedding a housing with material in order to maintain objects within the housing in a spatial relationship with respect to each other and with respect to the housing. Potting may be used to provide shock resistance and vibration resistance. Certain compositions for potting may be designed to establish a seal against moisture, solvents and corrosive agents.

The materials used to form the potting compound range in hardness from very soft to hard and rigid and are designed to withstand various environments. The potting compound used to pot the battery cells may be designed to provide mechanical stability and impact resistance to a battery module intended for use in a vehicle, for example. There is a need for potting compounds that provide mechanical stability to the battery cells while minimally increasing the weight of the battery module. There is also a need for a potting compound for a battery module that provides mechanical stability and flame retardancy to the battery cells.

Summary of The Invention

Disclosed herein is a battery module comprising a battery cell and a potting compound associated with the battery cell. The potting compound is formed from: a flame retardant component; a first component having a compound reactive with isocyanates and water; and a second component having an isocyanate compound. The potting compound is a foam after curing.

The potting compound can have at least a V2 grade flame retardancy as measured by the UL94 plastic flammability test. The potting compound may have less than 0.50g/cm³The foam density of (a). The flame retardant component may be present in an amount of at least 15 wt% based on the total weight of the potting compound. The flame retardant component may be present in an amount of at least 30 wt% based on the total weight of the potting compound. The potting composition intended to form the potting compound may have sufficient fluidity to be stable at an equal height around the battery cell before curing.

The first component may have a viscosity of from greater than 1 to less than 100,000 cP. The second component may have a viscosity of greater than 1 to less than 50,000cP at a temperature of about 25 ℃ to about 35 ℃. The first component may have a viscosity of from greater than 1 to less than 1,500 cP. The second component may have a viscosity of greater than 1 to less than 1,000cP at a temperature of about 25 ℃ to about 35 ℃.

Also disclosed herein is a battery module comprising a battery cell disposed in a potting compound. The potting compound may be formed from the reaction product of: a first component having a compound reactive with isocyanates; and a second component having an isocyanate compound. The potting compound may further include a blowing agent, and a liquid flame retardant component present in an amount of about 15 wt% to about 60 wt%, based on the total weight of the potting compound.

The liquid flame retardant may include a phosphate ester. The compound reactive with isocyanates may be a polyether polyol. The isocyanate-reactive compound may have a functionality of 3 or more reactive with isocyanate. The isocyanate compound may have an average isocyanate functionality of 2 or greater.

The first component may have a viscosity of from greater than 1 to less than 100,000 cP. The second component can have a cP of greater than 1 to less than 50,000 at a temperature of about 25 ℃ to about 35 ℃. The first component may have a viscosity of from greater than 1 to less than 1,500 cP. The second component may have a viscosity of greater than 1 to less than 1,000cP at a temperature of about 25 ℃ to about 35 ℃.

Also disclosed herein is a battery module comprising a first battery cell disposed in a polyurethane foam potting compound. The potting compound has a concentration of less than 0.50g/cm³The density of (c). The foam potting compound has at least a V2 grade flame retardancy as measured by the UL94 plastic flammability test. The potting compound may be dispersed to a substantially uniform height from the battery module housing having sufficient fluidity to be disposed between the first battery cell and the battery module housing disposed around the first battery cell prior to curing.

While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

Brief Description of Drawings

Fig. 1 is a perspective view of a battery module according to some embodiments.

Fig. 2 is a top view of a battery module according to some embodiments.

Fig. 3 is a front view of a battery module according to some embodiments.

Fig. 4 is a perspective view of a battery module according to some embodiments.

Fig. 5 is a top view of a battery module according to some embodiments.

Fig. 6 is an exploded view of a battery module according to some embodiments.

Detailed Description

Disclosed herein are low density and flame retardant potting compounds. The potting compound has a flame retardancy of at least class V2 as measured by the UL94 plastic flammability test. In some cases, the potting compound has at least a V1 grade flame retardancy as measured by the UL94 plastic flammability test. In some embodiments, the potting compound has at least a V0 grade flame retardancy as measured by the UL94 plastic flammability test.

The potting compound may be formed from a potting composition that is applied as a liquid and cured to form the potting compound. The potting composition has sufficient fluidity prior to curing to allow the potting composition to be applied as a liquid around the battery cell and then to stabilize at a substantially uniform height around the battery cell. The potting composition disclosed herein can be applied as a liquid and flowed around the battery cells and through the spaces defined between adjacent battery cells to form a potting compound prior to curing. The potting compound can be used to pot the battery cells and form a lightweight battery module. The potting compound is useful for potting battery cells and provides mechanical stability and flame retardancy after curing.

The potting compound may be formed of materials that form a foam when cured, including silicones, epoxies, such as one or two-part epoxies, or polyurethanes. In some embodiments, the potting compound comprises a polyurethane foam. The potting compound may be formed from a polyurethane composition that is liquid prior to curing and cures and hardens in the form of a foam to form the potting compound. In some embodiments, the potting compound is formed from a polyurethane foam having a low density and including a flame retardant.

As used herein, a foam is defined as a substance formed from a bulk material that defines a cavity throughout the substance. The cavity may be filled with a gas, such as air, oxygen, carbon dioxide, nitrogen, or any suitable gas. The cavities form a porous structure throughout the bulk material. For example, the potting composition may be a liquid mixture of components that react with each other and release a gas that forms bubbles throughout the liquid. The liquid potting composition hardens upon curing to form a solid potting compound, which is a solid substance having a cavity throughout the solid substance. The cavities result in a lower density of the solid matter than if the solid matter were formed entirely of the bulk material without a porous structure. The foam may be closed cell or open cell. Closed cell refers to a foam having cavities that form discrete pockets of air completely surrounded by solid material. Open cell refers to a foam having cavities that form interconnected air pockets.

It is also contemplated that in some cases, the low density potting compound may be formed from a bulk substance (bulk substrance) including expanded or unexpanded microspheres, such as syntactic foams. For example, solid particles formed from glass or polymeric materials may be used to form three-dimensional shapes, such as beads or bubbles, that define a center filled with a gas. These beads or bubbles may be distributed throughout the bulk substance (bulk substrance) which may solidify and embed the beads or bubbles, thereby reducing the overall density of the solidified potting compound.

After curing, the potting compound in the form of a foam has a density lower than that of the potting composition in the form of a liquid. In some embodiments, the potting compound has less than about 0.60g/cm after curing³Less than about 0.50g/cm³Less than about 0.40g/cm³Less than about 0.30g/cm³Less than about 0.20g/cm³Less than about 0.10g/cm³Or less than about 0.05g/cm³The density of (c). For example, the potting compound may be a compound having about 0.02g/cm³About 0.05g/cm³About 0.10g/cm³About 0.20g/cm³To about 0.30g/cm³About 0.40g/cm³Or about 0.50g/cm³Or a density between any pair of the foregoing values, although potting compounds having other densities are also further contemplated.

The potting composition may 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 may contain a flame retardant. The first component and the second component may be selected to form a thermoplastic polyurethane component (TPU). After mixing the first component and the second component, the potting composition may be a blend of a polyurethane component and a liquid flame retardant component. The first and/or second component may also contain one or more additional additives.

A first component

The first component is a liquid at room temperature (about 25 ℃ to about 35 ℃). 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 100cP, about 200cP, about 300cP, or about 400cP to about 1100cP, about 1200cP, about 1300cP, or about 1400cP, about 10,000, about 20,000, about 30,000, about 40,000, or up to 100,000, or a viscosity between any pair of the foregoing values, although components having other viscosities are further contemplated.

The first component includes one or more compounds reactive with isocyanates. The compound reactive with isocyanates may be an active hydrogen-containing compound such as an amine, alcohol or thiol. The first component includes an isocyanate-reactive compound having a functionality of 2 or greater. Preferred isocyanate-reactive compounds are those having a functionality of 3 or greater. Suitable compounds reactive toward isocyanates are those which are liquid at room temperature. Preferred compounds reactive toward isocyanates are those having a low viscosity at room temperature. For example, suitable isocyanate-reactive compounds may have a viscosity of greater than 1 to less than about 800cP, less than about 700cP, less than about 600cP, or less than about 500cP at room temperature. Preferred examples of compounds reactive with isocyanates include those having a viscosity of less than about 200cP, less than about 190cP, less than about 180cP, or less than about 170cP at room temperature (about 25 ℃ to about 35 ℃).

The compound reactive with isocyanates may be a polyol. The compound reactive with isocyanates may be a combination of two or more polyols. For example, the compound reactive with isocyanates can be a diol polyol, a triol polyol, a tetraol polyol, or a higher polyol, and combinations thereof. Preferred examples of polyols that can be used as compounds reactive with isocyanates include those having low viscosity at room temperature.

The polyol may be selected from 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 glycols, and mixtures and combinations thereof. In some embodiments, suitable polyethers can have a number average molecular weight (Mn) of about 200, about 300, about 400, about 600 to about 800, about 1,000, about 4,000, or about 6,000, or a molecular weight between any pair of the foregoing values, although polyethers having other molecular weights are further contemplated.

In some embodiments, suitable polyols may include polyhydroxy ethers, including substituted or unsubstituted polyalkylene ether glycols or polyhydroxy polyalkylene ethers; a polyhydroxy polyester; ethylene oxide or propylene oxide adducts of polyols and monosubstituted esters of glycerol; polymer polyols, such as in situ polymerized graft polyols containing a proportion of vinyl monomers; and mixtures and combinations thereof. Further examples of suitable polyols include poly (diethylene glycol adipate).

In some embodiments, homopolymers and copolymers of polyoxyalkylenes may be used. In some embodiments, the copolymer of polyoxyalkylene polyol may comprise an adduct of at least one compound comprising ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, 2-ethylhexanediol-1, 3, glycerol, 1,2, 6-hexanetriol, trimethylolpropane, trimethylolethane, tris (hydroxyphenyl) propane, triethanolamine, triisopropanolamine and one compound comprising ethylene oxide, propylene oxide and butylene oxide.

In some embodiments, suitable polyester polyols may be formed from the reaction of one or more polyols having from about 2 to about 15 carbon atoms with one or more polycarboxylic acids having from about 2 to about 14 carbon atoms. Examples of suitable polyols include ethylene glycol, propylene glycol such as 1, 2-propylene glycol, 1, 3-propylene glycol, glycerol, pentaerythritol, trimethylolpropane, 1,4, 6-octanetriol, butanediol, pentanediol, hexanediol, dodecanediol, octanediol, chloropentanediol, glycerol monoallyl 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 the like.

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

Suitable commercially available polyols that may be used to form the polyurethane potting composition include the triol polyether polyol sold under the trade name POLY-G30-240 (available from the Monvent Chemical Group, located in Houston, TX), the triol polyether polyol sold under the trade name VORANOL 230-.

A second component

The second component is a liquid at room temperature (about 25 ℃ to about 35 ℃). 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 can have a viscosity of about 40cP, about 60cP, about 80cP, or about 100cP to about 600cP, about 700cP, about 800cP, about 900cP, about 1000, about 10,000, about 20,000, about 30,000, or up to about 50,000 at room temperature (about 25 ℃ to about 35 ℃), or a viscosity between any pair of the foregoing values, although components having other viscosities are also further contemplated. In a preferred embodiment, the second component has a viscosity of no greater than 200cP at room temperature.

The second component includes an isocyanate compound. The isocyanate compound has an average isocyanate functionality of 2 or greater. Preferred isocyanate compounds include those that are liquid at room temperature, including those having a viscosity of no greater than 300cP, no greater than about 200cP, or no greater than about 100cP at room temperature (about 25 ℃ to about 35 ℃). 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, such as an isocyanate-terminated oligomer, that is reacted with an isocyanate compound. In some embodiments, the isocyanate compound may be a polymeric isocyanate.

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 with an isocyanate group.

Suitable isocyanate compounds include diphenylmethane isocyanate compounds such as diphenylmethane diisocyanate, including isomers thereof, diphenylmethane diisocyanate (MDI), carbodiimide modified MDI, hydrogenated diphenylmethane isocyanate (HMDI), Hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI), polymeric diphenylmethane isocyanates, diphenylmethane-4, 4' -diisocyanate, diphenylmethane-2, 2' -diisocyanate, diphenylmethane-2, 4' -diisocyanate and other oligomeric methylene isocyanates; toluene diisocyanate compounds (TDI), including isomers thereof, tetramethylxylene diisocyanate (TMXDI), isomers of naphthalene diisocyanate, isomers of triphenylmethane triisocyanate, and mixtures and combinations thereof, although other isocyanates are further contemplated. In some cases, aliphatic di-, tri-, and polyisocyanates are also suitable isocyanate compounds, including, for example, hydrogenated aromatic diisocyanates, aliphatic polyisocyanates, or cycloaliphatic polyisocyanates, although other isocyanates are further contemplated. Suitable commercially available isocyanate compounds include modified liquid MDI (available from The Dow Chemical Company, in Midland, Mich.) sold under The trade name ISONATE143L or polymeric MDI (available from Huntsman Corporation, in The Woodlands, TX) sold under The trade name RUBINATE M.

In some embodiments, the isocyanate compound is present in the second component at a weight percentage of about 20%, about 30%, or about 40% to about 70%, about 80%, about 90%, or about 100%, or a weight percentage between any pair of the foregoing values, based on the total weight of the second component. In a preferred embodiment, the isocyanate compound is present in the second component at a weight percent of about 50%, about 55%, or about 60% to about 70%, about 75%, about 80%, or about 85%, or at a weight percent between any pair of the foregoing values, based on the total weight of the second component. In embodiments having more than one isocyanate compound, the total amount of all isocyanate compounds present in the second component has a combined weight percent of from about 20%, about 30%, or about 40% to about 70%, about 80%, about 90%, or about 100%, or a weight percent between any pair of the foregoing values, based on the total weight of the second component.

Foaming agent

The potting composition includes a foaming agent. Suitable blowing agents are those that can react with the remaining components of the potting composition to create gas pockets in the potting composition that form cavities upon curing of the potting compound. Chemical blowing agents include water, azodicarbonamide (e.g., for 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 foaming agent may be a gas that is injected into the battery potting composition such that gas pockets are created in the potting composition upon mixing of the components of the potting composition. Suitable blowing agents that may be injected into the battery encapsulation composition include nitrogen or carbon dioxide.

In some embodiments, the blowing agent may be a liquid. In some embodiments, the blowing agent is water. For example, where the potting compound is formed of polyurethane, water may be included to react with the polyurethane-forming components to form carbon dioxide gas when the polyurethane components are mixed. The carbon dioxide gas forms bubbles in the liquid potting composition. The bubbles may form a cavity therein after the polyurethane is cured and hardened to produce a foamed potting compound. In some embodiments, the foaming agent is present in the potting composition at a weight percentage of greater than 0, about 0.1%, about 0.5%, or about 1.0% to about 1.5%, about 2.0%, about 2.5%, or about 3.0%, or a weight percentage between any pair of the foregoing values, based on the total weight of the first component. In some embodiments, a blowing agent may be included in the first component. For example, in some embodiments, the blowing agent may be a liquid blowing agent included in the first component.

Flame retardant component

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

Suitable flame retardant components may include those having a viscosity of about 30cP, about 40cP, about 100cP, about 200cP, about 300cP or about 400cP to about 600cP, about 700cP, about 800cP, or about 900cP, or about 2000cP at room temperature (about 25 ℃ to about 35 ℃), or a viscosity between any pair of the foregoing values, although liquid flame retardants having other viscosities are also further contemplated. Preferred liquid flame retardant components include those having a viscosity of no greater than about 300cP at room temperature. For example, preferred liquid flame retardant components include those having a viscosity at room temperature of about 40, about 60, or about 80 or about 100 to about 150, about 200, about 250, or about 300, or a viscosity between any pair of the foregoing values, although flame retardants having other viscosities are further contemplated.

In some embodiments, the flame retardant component comprises a phosphate ester. The flame retardant component may include a halogenated phosphate ester. The flame retardant component may include one 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.

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

In some embodiments, a suitable commercially available flame retardant component may be a chlorinated phosphate ester sold under the trade name FYROL PCF (available from ICL Industrial Products, located at st.

The flame retardant component is present in at least one of the first or second components. The flame retardant component is present in at least one of the first or second components in a weight percent of greater than 0%, about 10%, about 20%, or about 30% to about 40%, about 50%, or about 60%, about 70%, or a weight percent between any pair of the foregoing values, based on the total weight of the component (first or second component) in which the flame retardant component is present. In some embodiments, a flame retardant component may be present in both the first component and the second component.

In some embodiments, the total amount of the flame retardant component in the potting composition is a weight percentage or a weight percentage between any pair of the foregoing values of about 15%, about 20%, about 25%, or about 30% to about 40%, about 45%, about 50%, about 55%, or about 60%, based on the total weight of the potting composition. For example, the first flame retardant component may be present in the first component at a weight percent of about 30%, about 35%, or about 40% to about 45%, about 50%, or about 55%, or a weight percent between any pair of the foregoing values, based on the total weight of the first component; and the second flame retardant component may be present in the second component in a weight percent of about 20%, about 25%, or about 30% to about 35%, about 40%, or about 45%, or a weight percent between any pair of the foregoing values, based on the total weight of the second component.

It has been found that in some cases, a suitable amount of flame retardant component in the potting composition will provide a suitable level of flame retardancy without compromising other desirable characteristics. For example, in some cases, the stiffness, hardness, flexibility, durability, or structural resilience of certain foam compounds may not be suitable when high amounts of flame retardant are present. In some embodiments, a suitable weight percentage of the flame retardant component in the polyurethane foam (to provide a suitable level of flame retardancy and to provide a suitably strong potting compound) may be in an amount of from about 25%, about 30%, or about 35% to about 40%, about 45%, or about 50% of the total weight of the potting composition.

Optionally additional additives

The potting composition may optionally include additional additives, either as separate components or mixed into one or more of the above components to form the first and/or second components. The optional additional additives may be present in the potting composition at a weight percentage of greater than 0, about 0.1, about 0.5, or about 1 to about 5, about 10, about 20%, or about 30%, or a weight percentage between any pair of the foregoing values, based on the total weight of the potting composition. The weight percentage of the optional additional additives may apply to the total amount of all additional additives present in total or to each additional additive individually.

Some examples of additional additives that may be added to either or both of the first or second components include, but are not limited to, cross-linkers, chain extenders, wetting agents, thixotropic agents (thixotrops), nucleating agents, surfactants, diluents, anti-settling agents, flame retardant enhancers, and components and combinations thereof. In some embodiments, the optional additional additives include waxes, mold release agents (release agents), antioxidants, reinforcing fillers, pigments, heat stabilizers, UV stabilizers, plasticizers, rheology modifiers, processing aids, lubricants, mold release agents, or components or combinations thereof. Suitable reinforcing fillers include mineral fillers and glass fibers.

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 may be used to react the isocyanate compound with the isocyanate-reactive compound and the remaining components. Suitable catalysts include, but are not limited to, triol catalysts, tetraol (tetra polyol) catalysts, or tertiary amine catalysts. Further examples of suitable catalysts include various alkylamines, alkyl ethers or alkyl thiol ethers, such as those of bismuth or tin, wherein the alkyl portion has from 1 to about 20 carbon atoms. Some examples include bismuth octoate, bismuth laurate, and the like. Other catalysts include various tin catalysts such as tin octoate, dibutyltin dioctoate, dibutyltin dilaurate, and the like.

In the example of a polyurethane potting composition, the catalyst may be present in an amount of greater than 0, about 0.02, about 0.05, or about 0.1 to about 0.25, about 0.75, or about 1%, or a weight percentage between any pair of the foregoing values, based on the total weight of the battery potting composition. In some embodiments, the cross-linking or wetting agent may be present in the potting composition at a weight percentage of greater than 0, about 0.1, about 0.5, or about 1 to about 5, about 7, or about 10%, or a weight percentage between any pair of the foregoing values, based on the total weight of the potting composition. In some embodiments, for example, a surfactant suitable for stabilizing the foam structure or facilitating wet out (wet out) may be present in the potting composition at a weight percent of greater than 0, about 0.1, about 0.5, or about 1 to about 2, about 3, or about 4%, or a weight percent between any pair of the foregoing values, based on the total weight of the potting composition. In some embodiments, the nucleating agent may be present in the battery potting composition at a weight percentage of greater than 0, about 0.1, or about 0.5 to about 1, about 1.5, or about 2%, or a weight percentage between any pair of the foregoing values, based on the total weight of the battery potting composition.

The first and second components are combined to form a potting composition having a flame retardant component. For example, in an embodiment of a polyurethane for forming the foam potting composition, the first and second components are mixed to form the polyurethane. The polyurethane may be present in the potting composition at a weight percent of about 30%, about 40%, or about 50% to about 60%, about 70%, or about 80%, or a weight percent between any pair of the foregoing values, based on the total weight of the potting composition. In some cases, one technique to calculate the amount of polyurethane present in the potting composition is to use theoretical calculations based on the starting components. That is, the weight percentages of all components forming the polyurethane (which would result in a 100% polyurethane yield if the starting components) are added. The total amount of these components is then taken as a weight percentage of the total amount of the potting composition to give the weight percentage of polyurethane in the potting composition.

Any known method of reacting a first component with a second component may be used. In embodiments comprising a polyurethane potting composition, any known method of combining first and second components to make a polyurethane foam may be used. In some embodiments, the combining process may be a "one-shot" process, wherein all reactants are mixed in a mixing vessel, such as a tank or reactor, and reacted and/or applied.

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

In some embodiments, the polyol of the first component may be present in the potting composition at a weight percentage of about 10%, about 20%, about 30%, or about 40% to about 50%, about 60%, about 70%, or about 80%, or at a weight percentage between any pair of the foregoing values.

Fig. 1 is a perspective view of an exemplary battery module 10. As shown in fig. 1, the battery module 10 includes a battery cell 20 and a battery case 22. In some embodiments, the battery cell 20 may be disposed within a battery housing 22 and potted in a potting compound 24. The battery cell 20 may be any suitable shape, generally having a bottom 30, a top 32, and a length defined therebetween. The battery housing 22 may be any suitable shape for housing the battery cell 20 and generally has a bottom 36, a top 38, and a wall 40 defined therebetween. The bottom 36 of the battery housing 22 defines an inner surface and an outer surface; the wall 40 of the battery housing defines an inner surface and an outer surface. The battery case 22 defines an enclosed space having an interior volume. Potting compound 24 is located within battery housing 22 and occupies a portion of the interior volume of battery housing 22. Potting compound 24 generally has a top 42, a bottom 44, and a height defined therebetween.

Fig. 2 is a top view of the battery module 10 shown in fig. 1. As shown in fig. 2, the battery case 22 forms a closed space large enough to enclose the battery cell 20 and other components, such as wires or tabs. The enclosed space defines the interior volume of the battery housing 22. The bottom 36 of the battery housing 22 may be closed and contain any contents of the enclosed space. The top 38 of the battery housing 22 may define an opening. The top 38 and/or opening can have a shape and size suitable to receive a lid that can be closed to separate the interior volume of the enclosure from the exterior of the battery housing 22. The cover may be configured to seal the interior volume of the enclosed space from the exterior of the battery housing 22 to prevent the intrusion of potential hazards such as fluids or flames. The battery housing 22 may be designed and configured to provide mechanical or structural support for the battery cell 20. Battery housing 22 may also be configured to provide protection from moisture, heat, cold, or any other potential factor that may cause damage to battery cell 20.

As shown, in one possible arrangement, the battery cell 20 may be formed as a cylinder. In further examples, the battery cells 20 may be shaped into any suitable shape or size as desired, such as cubes, spheres, pyramids, and the like. The battery cell shown in fig. 1 is shaped as a cylinder having a bottom 30, a top 32, and walls extending between the bottom 30 and the top 32. The bottom portion 30 may be the positive terminal of the battery cell 20, or may be the negative terminal, depending on the desired orientation. As shown, the bottom 30 of the battery cell 20 is seated in the potting compound 24. The potting compound 24 occupies a portion of the interior volume of the battery housing 22 and extends a substantially equal distance from the bottom 36 to the top 38 of the battery housing 22 at various points along the wall 40.

The battery cell may be used to form a battery. For example, multiple battery cells may be combined to form a single battery having a higher voltage or amperage than a single battery cell.

Fig. 3 is a front view of a battery module 50 including battery cells 52. Each of the battery cells 52 has a bottom 60, a top 62, and walls therebetween defining a length. The battery cell 52 may be disposed within a battery housing 64. The battery cells 52 define a gap 80 between each battery cell and an adjacent battery cell. The gap 80 has a width. The battery housing 54 has a bottom 66, a top 68, and walls 70 therebetween. The bottom 66 and the wall 70 define an enclosed space. The enclosed space of the battery housing 54 defines an interior volume. The interior volume of the battery housing 54 has a volume suitable for containing the battery cell 52 and the potting compound 56. Potting compound 56 has a bottom 82, a top 84, and a height 86 therebetween. The bottom portion 82 of the potting compound 56 abuts the inner surface of the bottom portion 66 of the cell housing 54. As shown, the top 84 of the potting compound 56 is between the bottom 66 and the top 68 of the battery housing 54. Typically, the top 84 of the potting compound 56 is lower than the top 62 of the battery cell 52, but it is also contemplated that in another arrangement, the top 62 of the battery cell 52 may be lower than the top 84 of the potting compound 56.

As shown, multiple cells 52 may be arranged in close proximity to one another, with each cell 52 oriented such that similarly charged terminals face in the same direction. Wires may be connected to the ends of the battery cells 52. Wires may be incorporated in power communication to combine the current from the battery cells 52, for example, to form a battery with a combined current or voltage. The battery module 50 may be used to power many applications, such as household appliances, outdoor electrical equipment, or vehicles, such as cars or boats.

To incorporate the battery cells 52 to form a battery, the battery cells 52 are connected with wires that conduct current from the battery cells 52. The battery cells 52 are typically arranged adjacent to one another, e.g., in rows or stacks, to form an ordered arrangement for ease of use and/or connection of electrical wires to the battery terminals. To conserve space and to form a compact battery, the battery cells 52 may be positioned in close proximity to one another. For example, the cells 52 may be arranged in rows or in a grid with the positive and negative terminals facing in the same direction. The battery cells 52 may be arranged and housed in an orderly arrangement within the battery housing 54, but it is also contemplated that in some cases, the battery module may be formed without the battery housing 54. For example, the battery cells 52 may be secured using alternative securing means, such as wires, ropes, straps, or the like, e.g., securing the battery cells 52 in a bundle.

In some cases it may be desirable to provide a portable battery, for example in the case of a battery to initiate ignition or to power a vehicle, such as a motorcycle, car or boat, as some examples. In situations where it is desirable for the battery to be portable, it is generally preferred to provide the battery with a stable structure and capable of withstanding forces, such as shock and/or vibration. In some cases, it is also desirable to provide batteries that are capable of withstanding extreme temperatures, including temperatures outside of the normal operating temperature of the battery. For example, in some cases, the battery may be subjected to high heat, and may be exposed to an open flame. One possible source of fire is one or more battery cells, for example due to an electrical short circuit or if the structure of the cell walls is damaged. One exemplary means that may be used to protect the battery cells 52 is a potting compound 56. Potting compound 56 may be associated with battery cell 52, such as disposed around battery cell 52 along one or more of the top, bottom, or walls of the battery cell. The battery cells 52 may be embedded or embedded in a potting compound 56 that maintains the battery cells 52 in a spatial relationship with respect to each other and/or with respect to the battery housing 54.

As shown in fig. 3, the battery cell 52 is disposed in a potting compound 56. A potting compound 56 is located around each cell 52. Where the battery contains multiple cells 52, the potting compound 56 may be located around each cell and in the gaps 80 or voids between the individual cells 52. Where the battery is contained within the battery housing 54, the potting compound 56 may be located between the battery cell 52 and the battery housing 54. Potting compound 56 may be positioned to provide suitable structural or mechanical support to battery cell 52.

In some cases, the battery cells 52 may be positioned to have a suitable distance between adjacent battery cells 52 such that the individual battery cells 52 are thermally and/or fluidly isolated from one another in the event of a leak or fire. In some cases, the battery cells 52 may be positioned to have a suitable distance between adjacent battery cells 52 such that a suitable thickness of potting compound 56 is located between adjacent battery cells 52 to provide sufficient shock absorption to prevent damage to the battery cells 52. The size of the void or gap 80 between adjacent cells 52 and/or battery housing 54 may be selected based on a number of variables including, but not limited to, the size and/or weight of each cell, the operating temperature of each cell, the size of each cell, and the intended use of the battery module 50. In some examples, the size of the gap between adjacent battery cells may be greater than 0mm, about 0.25mm, about 0.50mm, about 0.75mm to about 1.0mm, about 1.5mm, or about 2.0mm, or a length between any pair of the foregoing values, although battery modules having other configurations are also further contemplated. In some examples, the gap between the battery cell and the battery housing may be sized to be greater than 0mm, about 1.0mm, about 2.0mm, about 3.0mm to about 10mm, about 12mm, or about 14mm, although battery modules having other configurations are also further contemplated.

In some embodiments, potting compound 56 may be formed by first molding a material, such as a potting composition, into a suitable shape having a space defined by potting compound 56 for receiving one or more battery cells 52. Potting compound 56 may be formed by molding a potting composition in a size and shape to position potting compound 56 within battery housing 54 and to define one or more spaces to secure one or more battery cells 52 positioned in the spaces.

In some embodiments, the potting compound 56 may be formed by first disposing the battery cells 52 to a desired final position (e.g., secured together with wires or within the battery housing 54). A mold or holder may be used to hold the battery cells 52 in place in a spatial relationship with respect to one another. The battery cell 52 may be fixed in place and placed in a mold or other housing that surrounds the battery cell 52. In a further example, the battery cells 52 may be arranged in a desired final position in a spatial relationship with respect to each other and positioned within the battery housing 54, such as sitting on an inner surface of the bottom 66 of the battery housing 54. Once the desired arrangement of the battery cells 52 is completed, the potting compound 56 may be formed by flowing a potting composition around the battery cells 52 and through the gaps 80 or voids between adjacent battery cells 52. The potting composition may be applied as a liquid to flow through gaps 80 between adjacent cells 52 and between cells 52 and wall 70 of battery housing 54. As described above, the potting composition may be configured to be applied as a liquid that hardens to a solid and forms potting compound 56 after application. In some embodiments, the potting composition may be reactive such that the potting composition is applied as a liquid that flows around the cells 52 and through the gaps 80 between adjacent cells 52, and then hardens after the reaction is complete.

The potting composition may flow through gaps 80 between adjacent cells 52 and stabilize at an equal height around the cells 52 and in the gaps 80 or voids between the cells 52. For example, referring to fig. 3, the potting composition may be poured into a battery housing 54 having a battery cell 52 disposed therein. The liquid potting composition has sufficient fluidity prior to curing to allow the liquid potting composition to flow through the space defined by the gaps 80 between adjacent battery cells 52 and/or between the battery cells and the battery housing 54. The liquid potting composition is sufficiently fluid to be stable at substantially equal heights prior to curing to form the potting compound.

As used herein, flowability refers to the ease with which a substance moves under a particular set of conditions. Some of these conditions may include the temperature of the substance, the viscosity of the substance, or the size of the space through which the substance may flow. For example, for liquid potting compositions, the flowability of the liquid determines how well it behaves when poured and how well it flows between adjacent battery cells and/or between a battery cell and a battery housing.

In a preferred embodiment, the potting composition is sufficiently fluid that the potting composition can be poured around the battery cells 52 and stabilized at substantially equal heights around the battery cells 52 before the potting composition hardens to form potting compound 56. That is, the potting composition has sufficient fluidity to disperse to substantially the same height 86 at various locations around the battery cell 52 (e.g., throughout the battery housing 54) prior to curing to form the potting compound.

In some embodiments, the height 86 of potting compound 56 may be measured from the bottom 82 of the potting compound to the top 84 of potting compound 56 for substantially equal height. This height may be measured at various locations throughout the potting compound 56 (e.g., near the walls of the battery housing 54 and toward the center of the battery housing 54, such as equidistant from two opposite sides of the housing). As used herein, substantially equal height means that the measurements of the height 86 of the potting compound at various locations are within 20% of each other.

In some cases, the test to determine a substantially equal height of potting compound 56 may be as follows. For a battery, such as battery module 50 having battery cells 52 arranged adjacent to each other, if the battery cells 52 have the same length and are arranged the same distance from the bottom and/or top of the battery housing 54, the potting compound is at a substantially equal height if the potting compound 56 is at approximately the same distance along the length of each battery cell 52. As used herein, substantially the same distance is defined as measurements of distances that are each within 20% of each other. In some cases, this test may be used to determine a substantially uniform height of potting compound 56 when the average size of each gap 80 between adjacent cells 52 is, for example, about 1 mm to about 3mm wide.

Providing a potting composition having sufficient fluidity to form substantially equal heights forms a potting compound that encapsulates each cell at substantially the same height. This provides a consistent amount of encapsulation around each battery cell. This may ensure proper encapsulation of the battery cell 52 to ensure a proper level of protection, such as a proper amount of structural stability and/or a proper amount of flame retardant to suppress a fire or flame. Providing potting compound having a substantially uniform height helps to balance the weight of the battery module 50 throughout the battery module 50. Suitable balancing or weight distribution helps to keep the battery module 50 stable when used in, for example, a moving vehicle. A suitably balanced battery module is preferred for use in a vehicle because it has a low tendency to rock or tilt in response to external forces, such as lateral or front-to-back acceleration.

Providing a low weight battery module may be preferred because it may make the battery module more portable and may reduce the energy required to move the battery module. For example, in an electric vehicle, it may be advantageous to provide a lighter battery module that can produce the same amount of power as a heavier embodiment. One option to achieve this is to use the same type and number of cells, but reduce the weight of the other components. Reducing the density of the potting compound may help reduce the total weight of the potting compound without reducing other desirable qualities. Providing a flame retardant component also helps to reduce the likelihood of uncontrolled ignition of the battery module.

After being fully cured, the potting compound may have a degree of elasticity, thereby buffering impact or vibration applied to the battery module in use of the battery module. This helps prevent safety problems caused by collisions between the battery cells and/or the battery cells coming off the wires.

The cured potting compound may have a degree of porosity that is controlled such that if one cell experiences a safety problem and leaks, any leaking material, such as fluid or gas, will be retained and isolated by the potting compound between adjacent cells to improve the safety performance of the battery module. In addition, the battery module has advantages of simple structure, low density, small size and low cost.

Potting compounds having low density, containing flame retardant and being foams are disclosed. The potting compound is suitable for forming a battery module. Also disclosed are potting compositions having suitable flowability to form a potting compound having a substantially uniform height throughout the battery module.

Fig. 4 is a perspective view of an exemplary battery module 100. As shown in fig. 4, the battery module 100 includes a battery cell 120 and a battery case 122. In some embodiments, battery module 100 includes more than one battery cell 120. The battery cell 120 may be any suitable shape, generally having a bottom 130, a top 132, and a length defined therebetween. The battery housing 122 may be any suitable shape for positioning the battery cells 120 within the battery housing 122. The battery housing 122 may be any suitable three-dimensional shape generally having a bottom 136, a top 138, and a wall 140 defined therebetween. The bottom 136 of the battery housing 122 defines an inner surface and an outer surface; the wall 140 of the battery housing 122 defines an inner surface and an outer surface. The battery case 122 defines an enclosed space having an interior volume.

As shown, the battery cell 120 may be disposed within a battery housing 122. As also shown, the battery cell 120 is associated with a potting compound 124. Potting compound 124 is located within battery housing 122 and occupies a portion of the interior volume of battery housing 122.

In some embodiments, the battery housing 122 forms an enclosed space that encloses the battery cells 120 and other components, such as wires, terminals, or tabs. The enclosed space defines an interior volume of the battery housing 122. The top 138 of the battery housing 122 may define an opening. The opening 138 may be shaped and sized to receive a cover that may be closed to isolate the interior volume of the enclosure from the exterior of the battery housing 122. The battery housing 122 may be configured to provide mechanical or structural support for the battery cell 120. The battery housing 122 may be configured to provide protection from potential damage to the battery cell 120, such as moisture, heat, cold, chemicals, shock, vibration, puncture, or flame. In some embodiments, the battery housing 122 may be configured to contain a potting compound 124 relative to the battery cells 120, including, for example, below the battery cells 120, between a first and adjacent battery cell 120, above the battery cells 120, or between the battery cells 120 and a wall 140 of the battery housing.

In some embodiments, the method of disposing the potting compound 124 relative to the battery cell 120 includes first disposing the battery cell 120 within the battery housing 122. One or more battery cells 120 may be positioned together in a battery housing, defining gaps 180 between adjacent battery cells 120. In some embodiments, a gap 180 may also be defined between the battery cell 120 and the wall 140 of the battery housing 122. In some examples, the potting compound 124 may be prepared in a separate container and then poured into the battery housing 122. For example, the components of the mixing potting compound 124 may be mixed to form a curable foam-forming composition, which may then be applied to the top 132 of the battery cell 120. The potting compound 124 may be added to place a layer of potting compound 124 having a thickness on top 132 of the battery cell 120. In some embodiments, the potting compound 124 may be located in the gaps 180 between adjacent battery cells 120. Potting compound 124 may be located in gap 180 between wall 120 and battery cell 120. The potting compound 124 may be positioned to define a space between a top of the potting compound 124 and a top 138 of the battery housing 122. In some embodiments, an amount of potting compound 124 may be cured into a suitable preformed shape and the preformed shape may be added to battery housing 122 in a suitable position relative to battery cell 120.

Fig. 5 is a top view of an exemplary battery module 200. The battery module 200 includes battery cells 220 disposed adjacent to each other. As shown in fig. 5, the battery cell 220 is disposed within a battery housing 222 having a top portion 238. The battery case 222 defines an interior volume. As shown, the battery housing 222 is sized such that the battery cell 222 can be positioned within the interior volume of the battery housing 222 with a space between the top 238 of the battery housing 222 and the top 232 of the battery cell 220. Also shown is a potting compound 224 disposed within the interior volume of the battery housing 222. As shown, the potting compound 224 has a generally planar shape and extends along the top 232 of the battery cell 220. Potting compound 224 may be provided to provide user access to terminals 290 of battery cells 220. In some embodiments, battery cell 220 includes a terminal 290 disposed on the top 232 of battery cell 220. Potting compound 224 may be disposed around terminals 290 and between top 232 of battery cell 220 and top 238 of battery housing 222.

In some embodiments, the method of disposing the potting compound 224 relative to the battery cell 220 includes first disposing the battery cell 220 within the battery housing 222. The potting compound 224 may be prepared in a separate container and then poured into the battery housing 222. An appropriate amount of potting compound 224 may be added to dispose a layer of potting compound 224 having a thickness on top 232 of battery cell 220 and/or between adjacent battery cells 22. In some embodiments, the potting compound 224 may be added such that the layer of potting compound 224 has a thickness suitable to cover the top 232 of the battery cell 220 and the terminals 290 protrude through the thickness of the potting compound 224. The potting compound may maintain the battery cells 220 in a spatial relationship relative to one another, such as by potting or encapsulating the terminals 290 to secure the battery cells 220 relative to one another.

Fig. 6 is an exploded view of an exemplary battery module 300. The battery module 300 includes battery cells 320 disposed adjacent to each other. In some embodiments, the battery module 300 includes a battery housing 322. The battery cell 220 is shown having a terminal 290 disposed on the top 232 of the battery cell 220. Potting compound 324 is also shown associated with battery cell 320. As shown in fig. 6, the battery cell 320 has a substantially planar shape. As shown, a piece (section of) potting compound 224 has a generally planar shape. In some configurations, a piece of potting compound 324 may be disposed between adjacent battery cells 320. For example, a piece of potting compound 324 may have a planar shape and be disposed parallel to the plane of the battery cell 320.

In some embodiments, the method of disposing the potting compound 324 relative to the battery cells 320 includes first disposing the battery cells 320 in a spatial relationship relative to one another, and then the potting compound 324 may be disposed into the voids between adjacent battery cells 320. For example, potting compound 324 may be poured into the voids between adjacent battery cells 320 and cured. As another example, the potting compound 324 may be cured and molded into a preformed sheet (section) that is then disposed in the voids between adjacent battery cells 320. An appropriate amount of potting compound 324 may be provided such that a sheet of potting compound 324 of an appropriate thickness is located between adjacent cells 220. In some embodiments, a sheet of potting compound 224 may be provided such that the sheet of potting compound 324 has a thickness suitable to provide a suitable level of flame retardancy. In some embodiments, the potting compound 320 may maintain the battery cells 320 in a spatial relationship with respect to one another, such as to absorb shock or vibration of the battery module 300.

Examples

The following non-limiting examples are included to further illustrate various embodiments of the present disclosure and do not limit the scope of the present disclosure.

The test method comprises the following steps:

viscosity test

The viscosity was measured with a Brookfield viscometer model RVF (from AMETEK Brookfield of Middleboro, Massachusetts) at a spindle speed of 20rpm and a temperature of 25 deg.C (77 deg. + -. 2 deg.F). The rotors used were either number 1 (up to 500cps), number 2 (up to 2000cps), or number 5 (up to 20,000cps), depending on the composition tested.

Foam density measurement

The weight of the empty measuring device (in this case the measuring cup) is recorded to within 0.1 gram. The maximum volume of the measuring device is measured by filling the measuring device with water and recording the amount of water required to fill the internal volume of the measuring device in milliliters. The various components were weighed out and added to the measuring device.

The components used to make the foam are mixed vigorously for 15-20 seconds. The sides and bottom of the measuring device were wiped sufficiently to ensure that all components reacted. The measuring device is struck sharply by tapping it on a hard surface to level the liquid. The measurement device is placed on the level surface, allowing the foam to rise freely without disturbance. The foam was allowed to solidify and cool for 60-70 minutes. After curing, the top of the foam bun (foam bun) is cut flush with the top of the measuring device using a flat tool, in this case a spatula or saw.

The measuring device containing the remaining foam was weighed and the weight in grams was recorded. The weight of the empty measuring device was subtracted from the weight of the measuring device containing the remaining foam to obtain the foam weight. The density was calculated by dividing the foam weight by the volume of the measuring device.

Fluidity test

The test compositions were mixed by hand mixing for a stirring time of 20 to 25 seconds. A sample of 65 to 70 grams of the test composition was then poured into one side of a container having dimensions of 8cm x 15cm x 9cm with 26 upright cylindrical cells (battery cells) of type 18650 in the container. The test was conducted at ambient temperatures of 21 ℃ to 24 ℃ (about 70 ° F to about 75 ° F).

The composition was visually observed as it flowed between the cylindrical battery cells. Depending on how well the composition cures at an even level of flatness around the cell, the following rating is given to the flatness on which the composition cures: unacceptable, acceptable, good and excellent. "Excellent" corresponds to a tested position within the container with less than 10% variation in height around the cell.

Burning test

The flame test was conducted according to the UL94 plastics flammability test, the vertical flame test method. A stick of combustion test samples was prepared in a mold having the following dimensions: 125 to 152mm long, 13mm wide and 9.5mm thick or 6.35mm thick. The foam is allowed to cure in the mold for 8 to 12 hours before removal. After molding, the sample bars were conditioned for a minimum of 48 hours at 25. + -. 2 ℃ and 50. + -. 5% RH prior to testing.

If a single specimen extinguishes within 10 seconds after removing the specimen from the flame of a burner and the total after flame time for a set of 5 specimens is within 50 seconds and there is no ignition cotton indicator (cotton indicator), the material is rated V-0. The V-1 and V-2 ratings require that a single sample be extinguished within 30 seconds after the sample is removed from the flame of the burner and that the total afterflame time for a group of 5 samples be within 250 seconds. The V-2 rating allows the cotton indicator to be ignited by burning particles.

Exemplary methods for forming potting compounds are described. This same procedure was used for all sample potting compounds, the amounts of the components being listed in table 1 below.

First and second component formation methods

To form the first component, a liquid polyether triol is first added to a mixing vessel. Mixing is initiated at the same time as the liquid polyether triol is added to the mixing vessel. The mixer speed was between 25 to 30rpms while adding the liquid polyether triol. Once all the liquid polyether triol is added, the mixer speed is increased to between 600 and 800 rpms.

In the samples that included them, liquid glycerin, triethanolamine, polyether, and anti-settling agent were then added to the mixing vessel. In the samples that included them, a thixotropic agent (thixorop) (fumed silica), a nucleating agent, a brominated flame retardant component, and a flame retardant enhancer (antimony trioxide) were then added to the mixing vessel. The contents of the mixing vessel are mixed for about 15 to about 20 minutes.

Distilled water was then added to the mixing vessel. In the samples that included them, the tertiary amine catalyst and surfactant were added while mixing the contents of the mixing vessel. Then adding a phosphate ester flame retardant. The contents of the mixing vessel were mixed for approximately 30 minutes to form the first component. After about 30 minutes, mixing was stopped and the first component was emptied from the mixing vessel.

To form the second component, liquid isocyanate is added to the mixing vessel. The liquid isocyanate was mixed at a mixer speed of 25 to 30rpm while being added to the mixing vessel. In the sample in which the flame retardant was included in the second component, the phosphate ester flame retardant was subsequently added to the mixing vessel. The contents of the mixing vessel are mixed for 15 to 20 minutes to form the second component. After 15 to 20 minutes, the mixing is stopped and the second component is emptied from the mixing vessel.

Potting composition and method for forming potting compound

The appropriate portions of the first component and the second component are poured into a mixing vessel. The mixing vessel used is larger than the total amount of material mixed to allow for vigorous mixing. For example, for a total of 75 grams of material, a minimum container size of 150 ml is recommended for mixing.

The higher density component is first placed in a mixing vessel and then the second component is added gently onto the first component. This helps to limit pre-reaction of the material to reaction at the interface only. The sides and bottom of each measuring vessel were wiped to ensure that almost all of the material being measured was added to the mixing vessel.

The timer was started and the contents of the mixing vessel were vigorously mixed with a flat-edged stirring implement for 20 to 30 seconds until the material was uniform and consistent in appearance. The sides and bottom of the mixing vessel were wiped during mixing. After mixing, the contents of the mixing vessel were immediately poured into a mold.

To form a non-flame retarded sample, essentially the same procedure as described for the flame retardant material was used. However, no flame retardant is added to the first or second component.

Comparative examples and samples 1 to 10 were prepared with the following components (given with trade names and suppliers, if applicable) and in the amounts listed in table 1: 2000M_nPPG diol polyether polyol (Low viscosity polyol-EO capped) (POLY G55-56, available from Monument Chemical Group, Houston, TX); glycerin 99.5% (triol crosslinker/humectant) (available from the Dow Chemical Company, Midland, MI); triethanolamine 99% (triol crosslinker/humectant/catalyst) (available from the Dow Chemical Company, Midland, MI); fumed silica (thixotropic agent) (AEROSIL 200 available from Evonik Industries, Essen, Germany); zinc stearate (nucleating agent) (NB-60, available fromself-PMCGroup, Memphis TN); zinc borate (flame retardant) (ZB-467, available from Lanxess Aktiengesellschaft, colongene, Germany). Ethylenebistetrabromophthalimide (brominated flame retardant) (SAYTEX BT-93, available from Albemarle Corporation, Baton Rouge, LA); distilled water (foaming agent); 1, 4-diazabicyclo [2.2.2]Octane solution (tertiary amine catalyst) (DABCO 33LV available from Evonik Industries, Essen, Germany); titanium dioxide (colorant/nucleating agent); tertiary amine catalysts (DABCO 8154 available from Evonik Industries, Essen, Germany); 700M_nPPG triol polyol (Low viscosity polyol) (POLY G30-240 available from Monvent Chemical Group, Houston, TX); 700M_nPolyether polyol (polyoxypropylene triol) (ARCOL LHT-240, available from Covestro, Leverkusen, Germany); tetrafunctional polyether polyols (poly-Q40-800E, available from arch chemicals, inc. of Norwalk, CT); 280M_namine/PPG tetraol polyol (tetra crosslinker/humectant/catalyst) (VORANOL 800, available from The Dow Chemical Company, Midland, MI); polyether polyols (VORANOL 230-; silicone surfactant (cell surfactant) (VORASURF DC 5160 available from Dow Chemical Company); halogenated phosphates (flame retardants) (FYROL PCF, available from ICL Industrial Products, st. louis, MO); trimethylpentanediol diisobutyrate (trimethyl pentanyl diisobutyrate) (viscosity diluent) (EASTMAN TXIB, available from EASTMAN chemical Company, Kingsport, TN); phosphate esters (flame retardants) (FYROL a710 available from ICL industrial products, st. louis, MO); isopropylated triaryl phosphate esters (phosphorus flame retardants) (reopos 35, available from LanxessAktiengesellschaft, colongene, Germany); cresyldiphenyl phosphate (flame retardant) (KRONITEX CDP, available from Lanxess Aktiengesellschaft, colongen, Germany); antimony trioxide (flame retardant performance enhancer) (AMSPEC SELECT, available from Amspec Chemical Corporation, Gloucester City, NJ); modified urea solution (rheological additive/anti-settling agent) (BYK-410 available from BYK USA inc., Wallingford, CT); modified liquid MDI (isocyanate-29% NCO) (ISONATE143L available from The Dow Chemical Company, Midland, MI); polymeric MDI (2.7 functionality) (RUBINATE M, available from Huntsman Corporation, The Woodlands, TX)。

Each composition was prepared and tested according to the test methods described above. The results and observations are listed in table 1.

Samples 11 to 14 were prepared in a similar manner as described for samples 1 to 10. Samples 11 to 14 were prepared with the following components (given with trade names and suppliers, if applicable) and in the amounts listed in table 2: glycerin 99.5% (triol crosslinker/humectant) (available from the Dow Chemical Company, Midland, MI); triethanolamine 99% (triol crosslinker/humectant/catalyst) (available from the Dow Chemical Company, Midland, MI); fumed silica (thixotropic agent (thixorop)) (TS-720, available from the Cabot corp., Boston, MA); zinc stearate (nucleating agent) (NB-60, available from PMC Group, Memphis TN); ethylenebistetrabromophthalimide (brominated flame retardant) (SAYTEX BT-93, available from Albemarle Corporation, Baton Rouge, LA); distilled water (foaming agent); 1, 4-diazabicyclo [2.2.2]Octane solution ((first) tertiary amine catalyst) (DABCO 33LV available from Evonik Industries, Essen, Germany); (second) tertiary amine catalyst (DABCO DMDEE, available from Evonik Industries, Essen, Germany); 700M_nPPG triol polyol (Low viscosity polyol) (POLY G30-240 available from Monvent Chemical Group, Houston, TX); 280M_namine/PPG Tetraol polyol (Tetraol crosslinker/Wet)Wetting agent/catalyst) (VORANOL 800 available from The Dow Chemical Company, Midland, MI); silicone surfactant (cell surfactant) (VORASURF DC 5160 available from the Dow Chemical Company); halogenated phosphates (flame retardants) (FYROLPCF available from ICL Industrial Products, st. louis, MO); silicone surfactants (EPH 190, available from Evonik Industries); diamine (curative) (LONZACURE DETDA 80 available from Lonza, inc., of allendale, NJ); antimony trioxide (flame retardant performance enhancer) (AMSPEC SELECT, available from Amspec chemical corporation, Gloucester City, NJ); modified urea solutions (rheological additives/anti-settling agents) (BYK-410/BYK-430 available from BYK USA inc., Wallingford, CT); fumed silica (TS-720); polymeric MDI (2.7 functionality) (RUBINATE M, available from Huntsman Corporation, The Woodlands, TX); halogenated phosphate ester (FYROLPCF) Silicone surfactant (VORASUF DC 5098, available from the Dow Chemical Company).

Compositions were prepared and tested according to the test methods described above. The results and observations are listed in table 2.

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

Claims (20)

1. A battery module, comprising:

a battery cell;

potting compound associated with a battery cell and formed from the following components

A flame retardant component;

a first component having

A compound reactive with isocyanates and water; and

a second component having

An isocyanate compound which is a mixture of at least one isocyanate compound,

wherein the potting compound is a foam.

2. The battery module of claim 1, wherein the potting compound has at least a V2 rating for flame retardancy as measured by the UL94 plastic flammability test.

3. The battery module of claim 1, wherein the first component has a viscosity of greater than 1 to less than 100,000cP, and wherein the second component has a viscosity of greater than 1 to less than 50,000cP, both at a temperature of about 25 ℃ to about 35 ℃.

4. The battery module of claim 1, wherein the first component has a viscosity of greater than 1 to less than 1500cP, and wherein the second component has a viscosity of greater than 1 to less than 1000cP, both at a temperature of about 25 ℃ to about 35 ℃.

5. The battery module of claim 1, wherein the potting compound has less than 0.50g/cm³The foam density of (a).

6. The battery module of claim 1, wherein the flame retardant component is present in an amount of at least 15 wt% based on the total weight of the potting compound.

7. The battery module of claim 1, wherein the flame retardant component is present in an amount of at least 30 wt% based on the total weight of the potting compound.

8. The battery module of claim 1, wherein the flame retardant component is a liquid prior to forming the potting compound.

9. The battery module of claim 1, wherein the potting composition intended to form the potting compound is sufficiently flowable to be stable at an equal height around the battery cells prior to curing.

10. A battery module, comprising:

a battery cell disposed in a potting compound formed from:

reaction product of the following Components

A first component having a compound reactive with isocyanates; and

a second component having an isocyanate compound, wherein,

a foaming agent; and

a liquid flame retardant component present in an amount of about 15 wt% to about 60 wt%, based on the total weight of the potting compound.

11. The battery module of claim 10, wherein the liquid flame retardant comprises a phosphate ester.

12. The battery module of claim 10, wherein the first component has a viscosity of greater than 1 to less than 100,000cP, and wherein the second component has a viscosity of greater than 1 to less than 50,000cP, both at a temperature of about 25 ℃ to about 35 ℃.

13. The battery module of claim 10, wherein the isocyanate-reactive compound has a functionality reactive with isocyanate of 3 or more.

14. The battery module of claim 10, wherein the isocyanate compound has an isocyanate functionality of 2 or greater.

15. The battery module of claim 10, wherein the potting compound further comprises at least one of a crosslinking catalyst, a nucleating agent, a surfactant or a flame retardant enhancer, and combinations thereof.

16. The battery module of claim 10, wherein the potting compound has at least a V2 rating for flame retardancy as measured by the UL94 plastic flammability test.

17. The battery module of claim 10, wherein the potting compound has less than 0.50g/cm³The density of (c).

18. The battery module of claim 10, wherein the potting composition intended to form the potting compound is sufficiently flowable to be stable at substantially equal heights around the battery cells prior to curing.

19. A battery module includes

A first battery cell disposed in a polyurethane foam potting compound,

wherein the potting compound has less than 0.50g/cm³And a density of

Wherein the potting compound has at least a V2 grade flame retardancy as measured by the UL94 plastic flammability test.

20. The battery module of claim 19, wherein the potting composition intended to form the potting compound is sufficiently flowable to disperse to a substantially uniform height around the first battery cell prior to curing.