Method for manufacturing a battery article and battery article manufactured therefrom

Abstract

The present invention relates to a method for manufacturing a battery article having a plurality of battery cells potted in a potting material, and a battery article prepared thereby. The method includes the following steps: S1. providing a battery case having a plurality of battery cells disposed therein, the battery cells separating the interior space of the battery case into a plurality of accommodating cavities; S2. preparing a potting compound; S3. filling the potting compound into the accommodating cavities, the relationship between the total filling time (T1) and the rise time (T2) of the potting compound satisfying T1<0.95*T2, preferably T1<0.8*T2; and S4. curing the potting compound to obtain a potting foam, the potting compound having an initial viscosity of less than 2500 cps at 25°C.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a battery article and to the battery article prepared therefrom.

[0002] Background technology To keep the battery cells in place during long-term operation, one solution is to fill the battery pack with a specific material (e.g., polyurethane), so that the battery cells are embedded in the material. Therefore, battery packs containing such materials have high shock and vibration resistance. Such materials are often called potting compounds.

[0003] However, battery packs contain many components, such as battery cells, bus bars, and cooling tubes, which create complex-shaped cavities inside the battery pack. Furthermore, the two components of polyurethane (isocyanate and polyol) are highly reactive. During manufacturing, it has been difficult to uniformly fill the cavity of a battery pack with polyurethane in a short time.

[0004] Summary of the Invention In view of the above expectations, the present disclosure provides a method for manufacturing a battery article, which allows a potting material to smoothly and uniformly fill a cavity in a battery pack, and the surface of the foam potting material is generally flat. Furthermore, the potting material is flame retardant.

[0005] In a first aspect, the present disclosure provides a method for manufacturing a battery article having a plurality of battery cells potted in a potting material, the method comprising the steps of: S1. Providing a battery case having a plurality of battery cells disposed therein, the battery cells separating an interior space of the battery case into a plurality of receiving cavities; S2. Preparing a potting compound; S3. Filling the potting compound into the receiving cavity, wherein the relationship between the total filling time (T1) and the rise time (T2) of the potting compound satisfies T1<0.95*T2, preferably T1<0.8*T2; S4. Curing the potting compound to obtain a potting foam; Including, the potting compound has an initial viscosity of less than 2500 cps at 25°C as measured in accordance with ASTM D2196-15, and a first component comprising at least one isocyanate; A second component, at least one polyol (P-1) having a molecular weight of 500 to 7000 g / mol, at least one chain extender having a molecular weight of less than 500 g / mol, at least one blowing agent, and At least one catalyst a second component comprising a liquid polyurethane reaction mixture obtained by mixing At least one of the first component and the second component comprises a flame retardant.

[0006] In a second aspect, the present application relates to a battery article prepared according to the method of the first aspect above, A battery case and a plurality of battery cells disposed within the battery case, the battery cells separating the interior space of the battery case into a plurality of receiving cavities; a polyurethane foam that partially or completely fills the receiving cavity, the battery cell being potted within the polyurethane foam; A battery article is provided, comprising:

[0007] MODE FOR CARRYING OUT THE INVENTION In the following description, the present disclosure will be further described with reference to embodiments to facilitate a full understanding by those skilled in the art. It should be understood that these embodiments are provided merely to facilitate a better understanding of the subject matter of the present disclosure and are not intended to impose any limitations on the scope of protection, applicability, or embodiments described in the claims. It should be understood that those skilled in the art can omit, replace, or add various technical features in each embodiment based on actual needs, without departing from the spirit of the present disclosure. Furthermore, technical features described in some embodiments can be combined with technical features described in other embodiments.

[0008] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0009] In this disclosure, the terms "comprise," "comprising," and various variations thereof can be understood as open-ended terms meaning "including, but not limited to," and in contrast, the term "consisting of" and various variations thereof can be understood to exclude any component, step, or procedure not specifically listed, and the term "one embodiment" can be understood to mean "at least one embodiment," and the term "another embodiment" can be understood to mean "at least one other embodiment." Other terms that may appear in this specification but are not mentioned should not be construed or limited in a manner contrary to the concept on which the embodiments of the present disclosure are based, unless explicitly stated.

[0010] Throughout this disclosure, expressions such as "a," "an," "the," and "one or more" are used interchangeably and are intended to include both the plural and the singular unless only the singular is expressly specified or clearly indicated by context. When only the singular is intended, the term "one" is typically used. The term "or" is generally intended to include the meaning "and / or" unless the content clearly dictates otherwise. As used herein, "preferred," "preferable," and "preferably" interchangeably refer to embodiments of the present disclosure that may offer certain advantages, under particular circumstances. However, other embodiments may also be preferred, under the same circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not suitable, nor is it intended to exclude other embodiments from the scope of the present disclosure.

[0011] All parts, ratios, and percentages (%) are by weight unless otherwise specified. For example, "wt. %" refers to percent by weight. Also, the recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 5 to 10 includes 5, 5.1, 5.2, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, ... 10).

[0012] Throughout this disclosure, references to temperature refer to values ​​measured under 101.325 Kpa.

[0013] The functionality is the "theoretical OH functionality" resulting from the functionality of the starter molecules used. Fractional functionality results from mixing starter molecules with different functionalities.

[0014] In this disclosure, "potting" refers to the process of filling a container (e.g., a battery case of the present disclosure) with a liquid potting compound (e.g., a polyurethane reaction mixture of the present disclosure). Once injected into the container, the liquid potting compound hardens, thereby protecting the internal components (e.g., a battery cell of the present disclosure) from shock and vibration.

[0015] I. Method of Manufacturing Battery Articles A battery assembly includes many components, such as battery cells, bus bars, cooling tubes, etc., which form a cavity with a complex shape inside the battery pack. It is expected that the potting compound can fill the cavity as much as possible. Furthermore, it is further expected that the resulting potting foam has a substantially flat surface.

[0016] In view of these expectations, in a first aspect, the present disclosure provides a method for manufacturing a battery article having a plurality of battery cells potted in a potting material, the method comprising the steps of: S1. Providing a battery case having a plurality of battery cells disposed therein, the battery cells separating an interior space of the battery case into a plurality of receiving cavities; S2. Preparing a potting compound; S3. Filling the potting compound into the receiving cavity, wherein the relationship between the total filling time (T1) and the rise time (T2) of the potting compound satisfies T1<0.95*T2, preferably T1<0.8*T2; S4. Curing the potting compound to obtain a potting foam; Including, the potting compound has an initial viscosity of less than 2500 cps at 25°C as measured in accordance with ASTM D2196-15, and a first component comprising at least one isocyanate; A second component, at least one polyol (P-1) having a molecular weight of 500 to 7000 g / mol, at least one chain extender having a molecular weight of less than 500 g / mol, at least one blowing agent, and At least one catalyst a second component comprising a liquid polyurethane reaction mixture obtained by mixing At least one of the first component and the second component comprises a flame retardant.

[0017] The potting compound of the present disclosure is a liquid polyurethane reaction mixture, which is a two-component system (i.e., a first component (also referred to as the "isocyanate component") and a second component (also referred to as the "polyol component"). In commercial applications, the isocyanate component and the polyol component are stored separately and, at the time of use, are delivered to a mixing chamber and mixed (e.g., static mixing or impingement mixing) to produce the liquid polyurethane reaction mixture. The liquid polyurethane reaction mixture is then immediately introduced into the cavity of the battery article (e.g., using a high-pressure or low-pressure system). The type of suitable machine is not limited. Preferred machines have an output capacity (e.g., greater than 0.01 L / sec) such that the required volume of potting compound can be introduced into the battery article in a relatively short time. The battery article can be open or closed.

[0018] During the above process, immediately after mixing, the isocyanate component and the polyol component begin to form urethane bonds, increasing the viscosity of the mixture and subsequently inducing a polyurea reaction (producing bubbles) that expands and hardens into a polyurethane potting foam. As a result, the polyurethane reaction mixture can only flow for a short time due to the high reactivity of the two components.

[0019] In order to fill the containment cavity in the battery article as fully as possible within a short time frame, the inventors have found that the potting compound should have good fluidity. According to the present disclosure, the potting compound (i.e., the polyurethane reaction mixture) has an initial viscosity of less than 2500 cps at a temperature of 25°C, as measured in accordance with ASTM D2196-15. The initial viscosity of the polyurethane reaction mixture is measured as follows: Immediately after mixing the first and second components, the viscosity of the resulting polyurethane reaction mixture is determined at a temperature of 25°C, as measured in accordance with ASTM D2196-15. The inventors have found that a potting compound having such an initial viscosity has good fluidity and processability, allowing the potting compound to quickly fill cavities with complex shapes. Meanwhile, good fluidity also facilitates the potting compound to flow evenly within a short period of time.

[0020] Furthermore, to ensure that the polyurethane reaction mixture has enough time to flow evenly, the total filling time (T1) of the present disclosure is controlled to be shorter than the rise time (T2) of the polyurethane reaction mixture, for example, T1<0.95*T2. In some preferred embodiments, the total filling time (T1) is shorter than 0.8 times the rise time (T2), i.e., T1<0.8*T2. The total filling time (T1) is understood to be the time from the start of filling to the completion of filling. The rise time (T2) is understood to be the time from the start of mixing the two components to the start of foaming of the mixture. The start of foaming of the mixture refers to volume expansion. According to the present disclosure, the rise time (T2) of the polyurethane reaction mixture is measured as follows: Immediately after mixing the first and second components, 50 g of the resulting polyurethane reaction mixture is added to a beaker (250 ml), and the time at which the mixture begins to expand at room temperature (e.g., 25°C) is observed with the naked eye and recorded. It will be appreciated that the rise time of the polyurethane reaction mixture will be slightly extended when the polyurethane reaction mixture is injected into a battery case containing multiple battery cells on an industrial scale.

[0021] By controlling the total filling time (T1) to be shorter than the rise time (T2), it is ensured that the polyurethane reaction mixture injected into the cell cavity has a certain flow time before the mixture hardens. In particular, when the total filling time (T1) is shorter than 0.8 times the rise time (T2), it is further ensured that the polyurethane reaction mixture has sufficient flow time.

[0022] Therefore, the combination of the novel potting compound and the above-described method has several advantages over conventional methods. By controlling the initial viscosity of the potting compound, the potting compound can sufficiently fill the cavity in a short time. By controlling the total filling time to be shorter than the rise time, it is ensured that the polyurethane reaction mixture injected into the battery cavity has a certain flow time in which the polyurethane flows evenly before hardening. Furthermore, the addition of a flame retardant further ensures that the finished battery article has good flame retardant performance.

[0023] In some preferred embodiments, the initial viscosity of the potting compound is greater than 500 cps and less than 2500 cps, as measured according to ASTM D2196-15, at a temperature of 25° C. If the potting compound is less than 500 cps, components (e.g., chain extenders) that have a viscosity much lower than other components (e.g., polyols) tend to separate from the potting compound and not be able to fully proceed with the next reaction.

[0024] The rise time of the polyurethane reaction mixture can be adjusted by changing the polyurethane recipe. In a preferred embodiment, the potting compound has a rise time of more than 30 seconds, preferably more than 100 seconds. In some embodiments, the rise time is preferably less than 250 seconds or 200 seconds in order to shorten the total curing time and improve production efficiency. In some preferred embodiments, the relationship between the total filling time (T1) and the rise time (T2) satisfies 0.2*T2 < T1, for example, 0.2*T2 < T1 < 0.95*T2, 0.2*T2 < T1 < 0.8*T2. From a practical perspective, the total filling time should not be too short (i.e., less than 20 seconds), otherwise, a typical machine may not have the required output and may not be able to evenly fill the required volume of the potting compound in a short time.

[0025] Depending on the geometric shape of the battery article and the expected potting form height, the required volume of the potting compound is determined accordingly. The battery article generally has a length of 0.3 to 3 meters, a width of 0.3 to 3 meters, and a height of 0.05 to 0.2 meters. On the other hand, the potted polyurethane reaction mixture is expected to be substantially flat at various positions around the battery case and have a height of about 0.8 to 1.1 times the height of the accommodation cavity. Therefore, the volume required for potting varies from 1 to 90 liters.

[0026] In some embodiments, the filling rate in step 3 is controlled to be 0.01 L / second to 1 L / second. The filling rate can be set on the spray head / nozzle. In some alternative embodiments, in step 3, the filling time per square meter is controlled to be 40 seconds to 200 seconds. Generally, the battery article has a size of 0.3 to 3 square meters. The filling time per square meter can be adjusted by controlling the moving speed and filling rate of the battery article. By controlling the filling rate or the filling time per square meter, it is ensured that the total filling time is shorter than the rise time of the polyurethane reaction mixture.

[0027] In step 4 (S4), the potting compound is cured, for example, at room temperature, preferably at a temperature of 10°C to 35°C, more preferably at a temperature of 15°C to 25°C, for 5 to 30 minutes to obtain a potting foam. The temperature is selected so that the entire curing process can be completed within 5 to 30 minutes, which is industrially advantageous.

[0028] Further details and embodiments of the potting compound are described below.

[0029] potting compound In step 2 (S2), a potting compound is prepared.

[0030] The potting compound of the present disclosure is a liquid polyurethane reaction mixture at room temperature. As explained above, the polyurethane reaction mixture includes a first component (the "isocyanate component") and a second component (the "polyol component") that react and then harden the polyurethane reaction mixture into a polyurethane foam after mixing. Viscosity increases after mixing. In the present disclosure, the potting compound has an initial viscosity of less than 2500 cps, preferably 500-2500 cps, and more preferably 600-1500 cps, at 25°C, as measured according to ASTM D2196-15. When injected into a battery article, such potting compound has sufficient fluidity to fully fill the containment cavity within the battery case.

[0031] The first component includes at least one isocyanate, the second component includes at least one polyol (P-1) having a molecular weight of 500 to 7000 g / mol, at least one chain extender having a molecular weight of less than 500 g / mol, at least one blowing agent, and at least one catalyst, and at least one of the first component and the second component includes a flame retardant.

[0032] First ingredient The first component comprises at least one isocyanate and is liquid at room temperature. In some embodiments, the first component comprises two or more isocyanates. In some embodiments, the first component further comprises at least one flame retardant.

[0033] Isocyanate The present disclosure does not limit the type of isocyanate. All known compounds having at least two isocyanate groups in the molecule are suitable. The isocyanate may be a monomeric, prepolymeric, and / or polymeric isocyanate.

[0034] Preferred isocyanates are liquids at room temperature. In some embodiments, the isocyanates have a viscosity of 1 to 1,000 cps, more preferably 100 to 500 cps, at 25° C., as measured according to ASTM D2196-15. For example, the isocyanates have a viscosity of 100 cps, 200 cps, 300 cps, 400 cps, or 500 cps.

[0035] Suitable isocyanates include, but are not limited to, aromatic isocyanates, aliphatic isocyanates, cycloaliphatic isocyanates, and araliphatic isocyanates. Examples of suitable isocyanates include tri-, tetra-, penta-, hexa-, hepta-, and / or octamethylene diisocyanate, 2-methylpentamethylene 1,5-diisocyanate, 2-ethylbutylene 1,4-diisocyanate, pentamethylene 1,5-diisocyanate, butylene 1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1,4- and / or 1,3-bis(isocyanatomethyl)cyclohexane (HXDI), cyclohexane 1,4-diisocyanate, 1- methylcyclohexane 2,4- and / or 2,6-diisocyanate and / or dicyclohexylmethane 4,4'-, 2,4'- and 2,2'-diisocyanate, diphenylmethane 2,2'-, 2,4'- and / or 4,4'-diisocyanate (MDI), polymeric MDI, naphthylene 1,5-diisocyanate (NDI), tolylene 2,4- and / or 2,6-diisocyanate (TDI), 3,3'-dimethyldiphenyl diisocyanate, 1,2-diphenylethane diisocyanate and / or phenylene diisocyanate, and combinations thereof.

[0036] In some preferred embodiments, the isocyanate is an isocyanate having two isocyanate groups. In some preferred embodiments, the isocyanate is an aromatic isocyanate. Diphenylmethane diisocyanate (MDI) and / or tolylene diisocyanate (TDI) are particularly preferred for the present disclosure.

[0037] Other possible isocyanates are given by way of example in "Kunststoffhandbuch, Band 7, Polyurethane" [Plastics Handbook, Volume 7, Polyurethane], Carl Hanser Verlag, 3rd edition, 1993, chapters 3.2 and 3.3.2.

[0038] Isocyanate prepolymers can be obtained by reacting an excess of the above isocyanate with additional polyol (P') at temperatures of, for example, 30 to 100°C, preferably about 80°C. For the preparation of the prepolymers used in accordance with the present invention, 4,4'-MDI is preferred, along with uretonimine-modified MDI and commercially available polyester-based polyols, such as those derived from adipic acid, or polyether-based polyols, such as those derived from ethylene oxide and / or propylene oxide. For the preparation of the prepolymers used in accordance with the present invention, 4,4'-MDI and polyols derived from ethylene oxide and / or propylene oxide are preferred.

[0039] Additional polyols (P') are known to those skilled in the art and are described, for example, in "Kunststoffhandbuch [Plastics Handbook], Volume 7, Polyurethane [Polyurethane]", Carl Hanser Verlag, 3rd Edition 1993, chapter 3.1.

[0040] Examples of suitable commercially available isocyanate compounds include LUPRANAT® M20S (manufactured by BASF) and LUPRANAT® MIPS (manufactured by BASF).

[0041] flame retardants According to the present disclosure, to reduce fire safety risks, at least one of the first and second components includes a flame retardant. Also, the potting compound includes one or more flame retardants. In some embodiments, the flame retardant is present in the first component, the second component, or both. In some preferred embodiments, the flame retardant is present in the first component.

[0042] The present disclosure does not limit the type of flame retardant, so long as it is liquid at room temperature. Examples of suitable flame retardants include, but are not limited to, phosphorus-containing materials, nitride-containing materials, and sulfur-containing materials.

[0043] Phosphite-containing materials are preferred, examples of which include phosphate esters such as ammonium phosphate, ammonium polyphosphate (APP), monoammonium phosphate, diammonium phosphate, trichloroethyl phosphate (TCEP), trichloropropyl phosphate (TCPP), resorcinol bisdiphenyl phosphate (RDP), triphenyl phosphate (TPP), triethyl phosphate (TEP), ammonium pyrophosphate, triphenyl phosphate, etc. In some more preferred embodiments, the flame retardant is a liquid phosphate ester, including chlorinated phosphate esters such as TCPP.

[0044] The total amount of the flame retardant varies from 3 to 30% by weight, preferably from 5 to 20% by weight, based on the total weight of the potting compound. For example, the flame retardant is present in amounts of 3%, 5%, 10%, 15%, 20%, 25%, and 30% by weight, based on the total weight of the potting compound, i.e., the sum of the first component and the second component.

[0045] Potting foams containing the above flame retardants have a flame retardancy level of at least V2 or higher as measured in accordance with the UL 94 test for flammability of plastics.

[0046] Second component The second component includes at least one polyol (P-1) having a molecular weight of 500 to 7000 g / mol, at least one chain extender having a molecular weight of less than 500 g / mol, at least one blowing agent, and at least one catalyst, wherein the polyol (P-1) has a molecular weight of 500 to 7000 g / mol. In some embodiments, the second component includes two or more polyols (P-1) having a molecular weight of 500 to 7000 g / mol. In some embodiments, the second component further includes at least one crosslinking agent. In still other embodiments, the second component further includes a component that is not reactive with the polyol, such as a flame retardant, a catalyst, a filler, an additive, or an auxiliary.

[0047] The second component is liquid at room temperature. In some preferred embodiments, the second component has a viscosity of 1 to 600 cps, more preferably 10 to 100 cps, at 25° C., as measured according to ASTM D2196-15.

[0048] Polyol (P-1) Suitable polyols (P-1) have at least two reactive groups (ie reactive hydrogen atoms) towards isocyanates.

[0049] Suitable polyols (P-1) are liquid at room temperature and have a molecular weight of 500 to 7000 g / mol, preferably 500 to 6000 g / mol, more preferably 2000 to 6000 g / mol, for example, 2000, 3000, 4000, 5000, or 6000 g / mol.

[0050] Examples of suitable polyols (P-1) include, but are not limited to, polyether polyols, graft polyether polyols, polyester polyols, polyolefin polyols, and mixtures thereof. Polyether polyols are preferred.

[0051] In some more preferred embodiments, the second component comprises at least one polyether polyol having a molecular weight of 2000 to 6000 g / mol, which provides good flow properties to the resulting polyurethane reaction mixture.

[0052] In some more preferred embodiments, the second component comprises at least one polyether polyol having a molecular weight of 2000 to 6000 g / mol and at least one graft polyether polyol, the addition of which enhances the mechanical strength of the resulting polyurethane foam.

[0053] The polyol (P-1) has a functionality of 2 or more, for example, 2, 3, or 4. The polyol (P-1) may be a diol polyol, a triol polyol, a tetrapolyol, or a higher polyol. In some preferred embodiments, the polyol (P-1) has a functionality of 2 to 3. In some more preferred embodiments, the polyol (P-1) is a polyether polyol having a functionality of 2 to 3.

[0054] Examples of suitable commercially available polyols (P-1) include LUPRANOL® 2095 (manufactured by BASF), LUPRANOL® 4003 / 1 (manufactured by BASF), LUPRANOL® 2090 (manufactured by BASF), LUPRANOL 3505 / 1 (manufactured by BASF), LUPRAPHEN® 3905 (manufactured by BASF), LUPRAPHEN® 3907 (manufactured by BASF), LUPRAPHEN® 3909 (manufactured by BASF), NJ 360S, and NJ 330S (manufactured by NingWu).

[0055] Based on the total weight of the second component, the total amount of polyol (P-1) is 60 to 95% by weight, preferably 60 to 90% by weight, and more preferably 65 to 75% by weight. For example, in some embodiments, the total amount of polyol (P-1) is 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% by weight.

[0056] Chain extenders / crosslinkers The chain extender has a molecular weight of less than 500 g / mol, for example, less than 400 g / mol, less than 300 g / mol, less than 200 g / mol, or less than 100 g / mol. The chain extender has two functional groups reactive with isocyanates, such as OH-, -SH, or NH2- groups. The chain extender is present in an amount of 5 to 30 wt%, preferably 10 to 25 wt%, and more preferably 10 to 20 wt%, based on the total weight of the second component.

[0057] Examples of chain extenders include aliphatic or aromatic amine-based chain extenders such as monoethylene glycol (MEG), diethylene glycol (DEG), 1,2-propanediol, 1,3-propanediol (DPG), 1,4-butanediol (BDO), 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, tetraethylene glycol, dipropylene glycol, cyclohexanediol, and aliphatic or aromatic diamines such as ethylenediamine, triethylenediamine, and / or diethyltoluenediamine (DETDA). Other possible low molecular weight chain extenders are described, for example, in "Polyurethane Handbook," Carl Hanser Verlag, 2nd edition 1994, chapters 3.2 and 3.3.2. In some preferred embodiments, the chain extender is selected from monoethylene glycol (MEG), 1,3-propanediol (DPG), and 1,4-butanediol (BDO).

[0058] In addition to the chain extender, the second component may further comprise at least one crosslinker. The crosslinker has at least three functional groups reactive with isocyanates. Examples of crosslinkers include 1,2,4-, 1,3,5-trihydroxycyclohexane, glycerin (GLY), trimethylolpropane (TMP), pentaerythritol, triethanolamine (TEOA), diethanolamine (DEOA), and low-molecular-weight hydroxyl-containing polyalkylene oxides based on ethylene oxide and / or 1,2-propylene oxide, as well as the aforementioned diols and / or triols. Other possible low-molecular-weight crosslinkers are described, for example, in "Polyurethane Handbook," Carl Hanser Verlag, 2nd edition 1994, chapters 3.2 and 3.3.2.

[0059] When chain extenders and crosslinker mixtures thereof are used, they are advantageously used in an amount of 5 to 30% by weight, preferably 10 to 30% by weight, based on the total weight of the second component.

[0060] In some preferred embodiments, the total amount of the flame retardant and the chain extender is more than 8 wt %, preferably 10-15 wt %, based on the total weight of the potting compound. When the potting compound has the flame retardant and the chain extender falls within the weight ratio range, the resulting polyurethane foam has good elasticity to protect the battery article from external impact and vibration.

[0061] foaming agent The second component includes at least one blowing agent, e.g., one or more blowing agents. The blowing agent preferably includes water. In some preferred embodiments, water is used as the only blowing agent. The water reacts with the isocyanate to form carbon dioxide gas, generating bubbles within the potting foam. Therefore, the resulting potting foam has a relatively low density and weight.

[0062] The blowing agent may further include other chemical and / or physical blowing agents known in the art. Chemical blowing agents are compounds that form gaseous products by reacting with isocyanates, such as water or formic acid. Physical blowing agents are compounds that are dissolved or emulsified in the starting materials for polyurethane production and vaporize under the conditions of polyurethane formation. Examples include hydrocarbons, halogenated hydrocarbons, and perfluorinated alkanes, such as perfluorohexane and fluorochlorocarbons, as well as other compounds such as ethers, esters, ketones, and / or acetals.

[0063] The blowing agent is present at 0.2 to 2 wt %, preferably 0.5 to 1 wt %, based on the total weight of the second component.

[0064] catalyst The catalyst significantly accelerates the reaction of the polyol (P-1) and, optionally, the chain extender and crosslinker, as well as the chemical blowing agent, with the isocyanate. Any catalyst known in the field of polyurethane catalysts can be used. These include basic amine catalysts and metal-based catalysts. In a preferred embodiment, the catalyst comprises an incorporable amine catalyst. In a more preferred embodiment, the catalyst comprises a delayed action catalyst. Delayed action catalysts are well known in the art and provide a long open time for the reaction mixture at room temperature and rapid cure at elevated temperatures.

[0065] The incorporable amine catalyst has at least one, preferably 1 to 8, and particularly preferably 1 to 2, isocyanate-reactive groups, such as primary amine, secondary amine, hydroxy, amide, or urea groups, preferably primary amine, secondary amine, or hydroxy groups. Incorporable amine catalysts are primarily used in the production of low-emission polyurethanes, particularly those used in automotive interiors. These catalysts are known and are described, for example, in EP 1 888 664. They include compounds that preferably contain one or more tertiary amino groups along with an isocyanate-reactive group. Preferably, at least one tertiary amino group of the incorporable catalyst has at least two aliphatic hydrocarbon moieties, preferably having 1 to 10 carbon atoms per moiety, particularly preferably having 1 to 6 carbon atoms per moiety. The tertiary amino group has two moieties independently selected from methyl and ethyl moieties, and it is particularly preferred that it has another organic moiety. Examples of incorporateable catalysts that can be used are bisdimethylaminopropyl urea, bis(N,N-dimethylaminoethoxyethyl)carbamate, dimethylaminopropyl urea, N,N,N-trimethyl-N-hydroxyethyl bis(aminopropyl ether), N,N,N-trimethyl-N-hydroxyethyl bis(aminoethyl ether), diethylethanolamine, bis(N,N-dimethyl-3-aminopropyl)amine, dimethylaminopropylamine, 3-dimethylaminopropyl-N,N-dimethylpropane-1,3-diamine, dimethyl-2-(2-aminoethoxyethanol), and (1,3-bis(dimethylamino)propan-2-ol), N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine, bis(dimethylaminopropyl)-2-hydroxyethylamine, N,N,N-trimethyl-(3-aminopropyl)bis(aminoethyl ether), 3-dimethylaminoisopropyldiisopropylpropanolamine, and mixtures thereof.

[0066] An example of a delayed action catalyst is the carboxylic acid salt used in conventional basic amine catalysts.For example, the carboxylic acid salt of basic amine catalyst can be obtained by mixing the amine catalyst with a carboxylic acid, optionally in the presence of an alcohol such as ethylene glycol.For the alcohol that falls under the definition of chain extender or crosslinker, its amount is taken into account when calculating the amount of crosslinker and chain extender in the reaction mixture.

[0067] Conventional non-incorporable amine catalysts can include amidines such as 2,3 dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary amines such as triethylamine, tributylamine, dimethylbenzylamine, N-methyl, N-ethyl, and N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylbutanediamine, N,N,N',N'-tetramethylhexanediamine, pentamethyldiethylenetriamine, tetramethyldiaminoethyl ether, bis(dimethylaminopropyl)urea, dimethylpiperazine, 1,2 dimethylimidazole, 1 azabicyclo[3.3.0]octane, preferably 1,4-diazabicyclo[2.2.2]octane, and alkanolamine compounds such as triethanolamine, triisopropanolamine, N-methyl and N-ethyldiethanolamine, and dimethylethanolamine.

[0068] Suitable metal-based catalysts include organometallic compounds, preferably organotin compounds, such as tin(II) salts of organic carboxylic acids, such as tin(II) acetate, tin(II) octanoate, tin(II) ethylhexanoate, and tin(II) laurate, as well as dialkyltin(IV) salts of organic carboxylic acids, such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, and dioctyltin diacetate, and bismuth carboxylates, such as bismuth(III) neodecanoate, bismuth 2-ethylhexanoate, and bismuth octanoate, or mixtures thereof. The organometallic compounds can be used alone or, preferably, in combination with a strongly basic amine. In a particularly preferred embodiment, the catalyst used comprises or consists of a delayed action catalyst, particularly preferably an incorporable delayed action catalyst.

[0069] If catalysts are used, they can be used, for example, in concentrations of 0.001 to 5% by weight, in particular 0.05 to 2% by weight, respectively, as catalyst or catalyst combination, based on the weight of component (b).

[0070] Other ingredients The second component may further include fillers, other additives, and / or auxiliaries. The fillers may be organic or inorganic fillers known in the art. For example, inorganic fillers include silicate minerals, metal oxides such as alumina, titanium oxide, and iron oxide. Examples of auxiliaries and / or additives used include surfactants, foam stabilizers, cell regulators, external and internal mold release agents, fillers, pigments, dyes, flame retardants, antistatic agents, hydrolysis stabilizers, and fungistatic and bacteriostatic substances.

[0071] Further details of the starting materials used can be found, for example, in Kunststoffhandbuch [Plastics Handbook], volume 7, Polyurethane [Polyurethane], edited by Gunter Oertel, Carl-Hanser-Verlag, Munich, third edition 1993, chapter 5, Polyurethanweichschaumstoffe [Flexible Polyurethane Foams].

[0072] The first component and the second component are mixed in a weight ratio of 80:100 to 110:100. The isocyanate index is 80 to 120, for example, 80, 90, 100, 110, and 120.

[0073] II. Battery Articles Prepared According to the Present Method In a second aspect, the present disclosure provides a battery article prepared according to the method of the first aspect, comprising: A battery case and a plurality of battery cells disposed within the battery case, the battery cells separating the interior space of the battery case into a plurality of receiving cavities; a polyurethane foam that partially or completely fills the receiving cavity, the battery cell being potted within the polyurethane foam; A battery article is provided, comprising:

[0074] The battery article includes a battery case and a plurality of battery cells disposed within the battery case. The battery cells separate the interior space of the battery case into a plurality of storage cavities. The shape of the battery case and the battery cells is not limited. The polyurethane foam partially or completely fills the storage cavities. In some embodiments, the polyurethane foam fills 80% to 100% of the height of the battery article.

[0075] The polyurethane foam of the present disclosure is elastic, thus providing continuous cushioning and excellent shock absorption. The elastic polyurethane foam protects the internal components of the battery article from external shock and vibration. In some preferred embodiments, the polyurethane foam has a compressive yield strength of 0.3 to 6 MPa, preferably 0.5 to 3.5 MPa, as measured in accordance with ASTM D 1621 (10% stress). Therefore, battery articles partially or completely filled / potted with such polyurethane foam have excellent impact and vibration resistance. Furthermore, the battery article can pass a vibration test measured in accordance with SAE J2380-2013 (normal test) or GBT 31467.3-2015.

[0076] Polyurethane foams can be either "closed cell," where the majority of the cells remain intact, or "open cell," where the cells within the foam are interconnected.

[0077] In some embodiments, the polyurethane foam has a hardness of 50 to 90 Shore A, measured according to ISO 7619. Polyurethane foams having such hardness are particularly preferred, as this enables the polyurethane foam to provide mechanical stability to internal components.

[0078] In some embodiments, the polyurethane foam has a relatively low density, for example, 350 to 900 g / L, preferably 530 to 680 g / L. Polyurethane foams having such densities have a relatively low weight, which is particularly advantageous for reducing the overall weight of the battery article.

[0079] Example The present invention will be further described below with reference to examples and comparative examples, but these are not intended to limit the present invention. [Table 1]

[0080] Test Method Density (g / L):GB / T 6343-2008 Shore A hardness: ISO 7619 Viscosity (cp):ASTM D2196-15 Flammability: UL-94 Compressive yield strength: ASTM D 1621, 10% stress Vibration test: SAE J2380-2013 (normal test) & GBT 31467.3-2015

[0081] Potting Compound Preparation Example The first and second components of the polyurethane compounds of Examples 1-3 (Ex. 1-3) and Comparative Examples 1-3 (Com. Ex. 1-3) were prepared according to Table 1 by mixing the corresponding components and stored in separate containers. At the time of use, the two components were delivered to a mixing chamber under 150 bar in the mixing ratios shown in Table 1 and impingedly mixed to produce a liquid polyurethane reaction mixture (i.e., potting compound). The second components of Examples 1-4 and Comparative Examples 1-2 have the initial viscosities listed in Table 1 below. The initial viscosities of the resulting liquid polyurethane reaction mixtures of Examples 1-4 and Comparative Examples 1-2 are also listed in Table 1.

[0082] As shown in Table 1, the initial viscosities of the liquid polyurethane reaction mixtures of Examples 1 to 4 ranged from 700 to 900, allowing the resulting liquid polyurethane reaction mixtures to have the desired fluidity.

[0083] In contrast, the liquid polyurethane reaction mixture of Comparative Example 1 had an initial viscosity of 3,000, which was too high to have sufficient fluidity to flow evenly. The liquid polyurethane reaction mixture of Comparative Example 2 had an initial viscosity of 200. However, such a low viscosity was achieved by incorporating a large amount of a low-viscosity chain extender. However, due to the large amount of chain extender, the resulting liquid polyurethane reaction mixture was prone to phase separation because the viscosity of the chain extender was much lower than that of other components in the second component, such as polyol (P-1), allowing the large amount of chain extender to easily separate from the polyurethane mixture. Non-uniform distribution of the chain extender prevented uniform reaction with the isocyanate, which is undesirable. [Table 2]

[0084] Preparation example of battery article The battery pack includes a battery case and measures 40 cm (width) x 150 cm (length) x 11 cm (height). 120 battery cells are placed inside the battery case, i.e., at the bottom of the battery case. The diameter of the battery cell is 4.6 cm and the height is 8 cm. The surface area of ​​the battery case is 0.6 m. 2 The battery pack further includes other components. The battery cells and other components separate the interior space of the battery case into a plurality of receiving cavities.

[0085] The liquid polyurethane reaction mixtures of Examples 1 and 3 prepared according to Table 1 above were mixed and immediately injected into the containing cavity through a spray head. The specific process conditions are listed in Table 2 below. The liquid polyurethane reaction mixtures of Examples 1 and 3 were processed under different conditions as shown in Examples 1-1, 1-2, 3-1, and 3-2.

[0086] After injection, the battery pack was kept at room temperature (25°C) for hardening. The liquid polyurethane reaction mixture gradually hardened into a polyurethane foam. If necessary, trim the upper polyurethane foam and close the top cover of the battery case.

[0087] The rise time (T2) of the polyurethane reaction mixture was measured as follows: Immediately after mixing the first and second components, 50 g of the resulting polyurethane reaction mixture was added to a beaker (250 ml), and the time it took for the mixture to begin to expand at 25°C was observed with the naked eye and recorded. It will be appreciated that the rise time of the polyurethane reaction mixture will be slightly extended if the polyurethane reaction mixture is poured into a battery case containing multiple battery cells.

[0088] The evaluation results for each example are also recorded in Table 2. [Table 3]

[0089] The mechanical properties of the resulting polyurethane foams of Examples 1-1 and 3-1 were determined. As shown in Table 3, the cured polyurethane foams of both Examples 1-1 and 3-1 have good mechanical properties. Both the cured polyurethane foams of Examples 1-1 and 3-1 can pass the V-2 flame retardancy test (UL94), and Example 1-1 can even pass V-1. Furthermore, these foams also pass the vibration test (GBT-31467.3-2015). [Table 4]

[0090] Although the embodiments and examples of the present disclosure have been described above, those skilled in the art will understand that they are for illustrative purposes only and are not intended to limit the scope of protection of the present disclosure. The scope of protection of the present disclosure is defined by the appended claims. Those skilled in the art may make various modifications, equivalent substitutions, or improvements to these embodiments without departing from the scope and spirit of the present disclosure, and these modifications, equivalent substitutions, or improvements will fall within the scope of protection of the present disclosure.

Claims

1. A method for manufacturing a battery article in which a plurality of battery cells are potted in a potting material, comprising the steps of: S1. Providing a battery case having a plurality of battery cells disposed therein, the battery cells separating an interior space of the battery case into a plurality of receiving cavities; S2. Preparing a potting compound; S3. Filling the potting compound into the receiving cavity, wherein the relationship between the total filling time (T1) and the rise time (T2) of the potting compound satisfies T1<0.95*T2, preferably T1<0.8*T2; S4. Curing the potting compound to obtain a potting foam; Including, the potting compound has an initial viscosity of less than 2500 cps at 25°C as measured in accordance with ASTM D2196-15, and the potting compound a first component comprising at least one isocyanate; A second component, at least one polyol (P-1) having a molecular weight of 500 to 7000 g / mol, at least one chain extender having a molecular weight of less than 500 g / mol, at least one blowing agent, and At least one catalyst a second component comprising: a liquid polyurethane reaction mixture obtained by mixing The method, wherein at least one of the first component and the second component comprises a flame retardant.

2. 10. The method of manufacturing a battery article of claim 1, wherein in S3, the potting compound has a rise time of greater than 30 seconds.

3. 3. The method of manufacturing a battery article according to claim 1 or 2, wherein the relationship between the total filling time (T1) of the potting compound and the rise time (T2) satisfies 0.2*T2<T1.

4. The method for manufacturing a battery article according to claim 1 or 2, wherein in S3, the filling speed is controlled to be between 0.01 L / sec and 1 L / sec.

5. The method for manufacturing a battery article according to claim 1 or 2, wherein in S3, the filling time per square meter is controlled to be between 40 seconds and 200 seconds.

6. The method for manufacturing a battery article according to claim 1 or 2, wherein in S4, the potting compound is cured at a temperature of 10°C to 35°C, preferably 15°C to 25°C.

7. 2. The method for producing a battery article according to claim 1, wherein the polyol (P-1) has a molecular weight of 500 to 6000 g / mol, preferably 2000 to 6000 g / mol, and the polyol (P-1) has a functionality of 2 or greater.

8. 10. The method for producing a battery article according to claim 1 or 7, wherein the polyol (P-1) is present in an amount of 60 to 95 wt %, preferably 60 to 90 wt %, and more preferably 65 to 75 wt %, based on the total weight of the second component.

9. The method of manufacturing a battery article according to claim 1 , wherein the second component further comprises at least one cross-linking agent.

10. 10. The method of manufacturing a battery article according to claim 1, wherein the chain extender is present in an amount of 5 to 30 wt%, preferably 10 to 25 wt%, based on the total weight of the second component.

11. 11. The method of manufacturing a battery article according to claim 1 or 10, wherein the chain extender is at least one selected from the group consisting of ethylene glycol (MEG), butanediol (BDO), and propanediol (DPG).

12. 10. The method of manufacturing a battery article of claim 1, wherein the flame retardant is a liquid and is present in an amount of 3 to 30 wt%, preferably 5 to 20 wt%, based on the total weight of the potting compound.

13. 13. The method of manufacturing a battery article of claim 1 or 12, wherein the flame retardant comprises a liquid phosphate ester.

14. 2. The method for manufacturing a battery article according to claim 1, wherein the total amount of the flame retardant and the chain extender is greater than 8 wt%, preferably 10-20 wt%, based on the total weight of the potting compound.

15. 10. The method of manufacturing a battery article according to claim 1, wherein the blowing agent comprises water and is present in an amount of 0.2 to 2 wt%, preferably 0.5 to 1 wt%, based on the total weight of the second component.

16. The method of manufacturing a battery article of claim 1 , wherein the catalyst comprises a delayed action catalyst.

17. A battery article prepared according to the method of any one of claims 1 to 16, comprising: A battery case and a plurality of battery cells disposed within the battery case, the battery cells dividing an interior space of the battery case into a plurality of receiving cavities; a polyurethane foam partially or completely filling the receiving cavity, the battery cell being potted within the polyurethane foam; A battery article comprising:

18. 18. The battery article of claim 17, wherein the polyurethane foam has a compressive yield strength of 0.3 to 6 MPa as measured according to ASTM D 1621 (10% stress).

19. 18. The battery article of claim 17, wherein the polyurethane foam has a hardness of 50 to 90 Shore A, measured according to ISO 7619.

20. 18. The battery article of claim 17, wherein the polyurethane foam has a density of 350 to 900 g / L, preferably 530 to 680 g / L.

21. 18. The battery article of claim 17, wherein the polyurethane foam fills between 80% and 100% of the height of the containment cavity.

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