Compressable silicone foam and method for making the same

Abstract

A curable composition for preparing a compressible silicone foam comprises: an alkenyl group-containing component comprising an alkenyl double-terminated polyorganosiloxane, an alkenyl substituted MQ polyorganosiloxane, and an alkenyl substituted copolymerized organosiloxane; and a hydrogen radical-containing component, wherein the hydrogen radical-containing component comprises a hydrogen radical-substituted polyorganosiloxane. The curable composition includes a curing catalyst; a filler composition; and a blowing agent. A compressible foam made from the curable composition and a method of making a compressible foam from the curable composition are also disclosed.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 523,160, filed June 26, 2023, the contents of which are incorporated herein by reference in their entirety. Background Technology

[0003] This application relates to curable compositions for preparing compressible silicone foams, which can be used as thermal management sheets in batteries, particularly for delaying or preventing thermal runaway in lithium-ion batteries. This application also relates to methods for manufacturing compressible silicone foams, and battery assemblies and batteries comprising thermal management sheets containing compressible silicone foams.

[0004] The demand for electrochemical energy storage devices, such as lithium-ion batteries, is growing due to applications such as electric vehicles and grid energy storage systems, as well as the increasing use of multi-cell batteries such as e-bikes, uninterruptible power supply battery systems, and alternatives to lead-acid batteries. As their use increases, methods for thermal management are desired. For large-scale applications such as grid storage and electric vehicles, multiple electrochemical cells connected in series and parallel arrays are often used, which can lead to thermal runaway. Once a single cell is in thermal runaway mode, the heat generated by that single cell can trigger thermal runaway propagation reactions in adjacent cells, potentially leading to a cascade effect that can ignite the entire battery.

[0005] While attempts to mitigate thermal runaway in batteries have been considered, many have drawbacks. For example, modifying the electrolyte by adding flame-retardant additives or using an inherently non-flammable electrolyte has been considered, but these methods can negatively impact the battery's electrochemical performance. Other methods for thermal management or preventing cascaded thermal runaway include incorporating increased insulation between individual cells or cell packs to reduce heat transfer during thermal events. However, these methods may limit the upper limit of achievable energy density.

[0006] With the increasing demand for batteries with improved thermal management or reduced risk of thermal runaway, there is a corresponding need for battery methods and components that prevent or delay the diffusion of heat, energy, or both to surrounding individual cells. Summary of the Invention

[0007] The curable composition for preparing compressible silicone foam comprises: an alkenyl-containing component, based on the total weight of the curable composition, said alkenyl-containing component comprising: 30 to 75 wt% of an alkenyl-double-terminated polysiloxane; 0.5 to 5 wt% of an alkenyl-substituted MQ polysiloxane; 0.1 to 5 wt% of an alkenyl-substituted copolysiloxane; and a hydrogen-containing component (-H, hydrogen bonded to silicon), said hydrogen-containing component comprising a hydrogen-substituted polysiloxane; a curing catalyst; a filler composition; and a blowing agent.

[0008] Compressible silicone foams containing cured products of curable compositions represent another aspect of this disclosure.

[0009] The inclusion of compressible silicone foam in battery assemblies represents another aspect of this disclosure.

[0010] The battery, which includes an assembly for the battery and a housing that at least partially surrounds the assembly for the battery, represents another aspect of this disclosure.

[0011] Another aspect is a method for forming a compressible silicone foam sheet, the method comprising: casting a curable composition onto a first release layer; placing a second release layer on the side of the cast curable composition opposite to the first release layer to form a multilayer structure; passing the cast curable composition on a substrate through the gap between two rotating rollers to control the amount of the curable composition; and curing the curable composition to form a compressible silicone foam sheet.

[0012] The above and other features are illustrated by way of example with the following figures and specific embodiments. Attached Figure Description

[0013] The following figures represent exemplary embodiments.

[0014] Figure 1 This is a schematic cross-sectional view of one aspect of thermal management sheets.

[0015] Figure 2 This is a schematic diagram of one aspect of the thermal management sheet located between two electrochemical cells.

[0016] Figure 3 This is a schematic diagram of one aspect of the thermal management sheet located between two electrochemical cells.

[0017] Figure 4 This is a schematic diagram of one aspect of the thermal management sheet located in a single-cell array.

[0018] Figure 5This is a schematic diagram of one aspect of an assembly for a battery that includes thermal management sheets.

[0019] Figure 6 This is a graph showing the compressive stress (kPa) versus strain (%) for each embodiment.

[0020] Figure 7A This is an exploded view of the first device used for nail penetration testing.

[0021] Figure 7B yes Figure 7A The diagram shown is a non-exploded view.

[0022] Figure 8A This is a graph showing the temperature (°C) versus time (seconds) during the nail penetration test in Example 2.

[0023] Figure 8B This is a graph of voltage (V) versus time (seconds) during the nail penetration test in Example 2.

[0024] Figure 9A This is a graph showing the temperature (°C) versus time (s) during the nail penetration test in Example 2.

[0025] Figure 9B This is a graph of voltage (V) versus time (s) during the nail penetration test in Example 2.

[0026] Figure 10 The apparatus 5000 for thermal testing is shown.

[0027] Figure 11 By according to Figure 10 A graph showing the temperature (°C) detected by the device relative to time (minutes (min)). Detailed Implementation

[0028] Thermal management in batteries, such as preventing thermal runaway, is a challenge, especially in batteries comprising a large number of electrochemical cells. This is because adjacent cells to a cell experiencing thermal runaway can absorb enough energy from the event to rise above their designed operating temperature, causing adjacent cells to also enter thermal runaway. This propagation of the initiated thermal runaway event can lead to a chain reaction, where a single cell ignites an adjacent cell, thus triggering a cascade of thermal runaway events. Achieving effective thermal management characteristics in very thin sheets (e.g., sheets with a total thickness of 1 mm to 30 mm, or 1 mm to 20 mm, or 1 mm to 15 mm, or 1 mm to 10 mm, or 1 mm to 8 mm, or 1.5 mm to 8 mm, or 1.5 mm to 6 mm, or 2 mm to 4 mm) is particularly difficult. There is a growing demand for thin sheets to reduce article size and weight and to save material.

[0029] Silicone foams can be rigid and exhibit a sharp stress rise in the stress-strain response under compression, even at low strain levels. Silicone foams can be filled with a variety of materials. For example, due to their excellent flame-retardant properties, silicone foams can be used as thermal runaway prevention materials, for instance, in electric vehicle applications, and to meet regulatory standards, silicone foams can be filled with flame-retardant inorganic materials, flame-retardant organic materials, or combinations thereof. The fillers included in silicone foams can further contribute to undesirable stress-strain properties.

[0030] The inventors have discovered that silicone foam compositions comprising filler compositions are soft and compressible while maintaining desired thermal properties, and therefore can be used as thermal management sheets to prevent or reduce the intensity of cascade thermal runaway events. Foams prepared according to this disclosure can be used in various locations within batteries to delay or prevent thermal runaway. Foams can also improve the flame retardancy of batteries comprising multiple electrochemical cells. Foams can also reduce stress on adjacent electrochemical cells, thereby extending battery life. As mentioned above, existing filler foams can exhibit hardening behavior, thereby increasing the stress of the foam on the individual cells. Existing foams can also exhibit expansion near the end of the individual cell's life, which may lead to increased stress on the individual cells from aging foam. Excessive stress on the individual cells from the foam can lead to shortened battery life, individual cell leakage, or other safety-related problems.

[0031] Therefore, one aspect of this disclosure is a curable composition for preparing compressible silicone foam. The compressible silicone foam is selected to be inert to the general operating conditions of a battery, such as a lithium-ion battery, and serves as a carrier for the filler composition. To obtain the advantageous properties of the compressible silicone foam, specific combinations of materials for the curable composition are used, as described in more detail herein. The relative amounts of the components in the curable composition can be adjusted to provide the desired properties in the cured silicone foam.

[0032] The curable composition contains an alkenyl-containing component. The alkenyl-containing composition includes alkenyl-double-terminated polyorganosiloxanes, alkenyl-substituted MQ polyorganosiloxanes, and alkenyl-substituted copolyorganosiloxanes.

[0033] Alkenyl-double-terminated polyorganosiloxanes can be represented by the following formula:

[0034] ,

[0035] Where the subscripts a, b, c, and d are zero or positive integers, and follow these restrictions: if subscripts a and b are both equal to zero, then subscript c is greater than or equal to two; M has the formula R3SiO 1 / 2 D has the formula R2SiO 2 / 2 T has the formula RSiO 3 / 2 ; and Q has the formula SiO 4 / 2 Each R group independently represents hydrogen, and the terminally substituted C... 1-6 Alkenyl, substituted, and unsubstituted monovalent hydrocarbon groups each having 1 to 40 or 1 to 6 carbon atoms, subject to the following restriction: at least one, for example, at least two, of the R groups are alkenyl R groups. Suitable alkenyl R groups are exemplified as vinyl, allyl, 1-butenyl, 1-pentenyl, and 1-hexenyl, with vinyl being particularly useful. The alkenyl group is bonded to the end of the molecular chain, i.e., an alkenyl-terminated polyorganosiloxane. As used herein, an alkenyl-double-terminated polyorganosiloxane refers to a polyorganosiloxane in which both of the chain ends are alkenyl. In one aspect, an alkenyl-double-terminated polyorganosiloxane is a vinyl-double-terminated polyorganosiloxane. As used herein, vinyl is a group having the formula -CH=CH2, and "substituted vinyl" has the formula -CH=CR2, wherein the R group can be independently hydrogen or C. 1-6 The vinyl concentration in alkyl- and alkenyl-terminated polyorganosiloxanes can be, for example, from 0.001 to 3 wt%, or from 0.01 to 0.5 wt%, or from 0.01 to 0.15 wt%, or from 0.01 to 0.1 wt%, each based on the total weight of the alkenyl-terminated polyorganosiloxane.

[0036] When present, other silicon-bonded organic groups in alkenyl-terminated polyorganosiloxanes are exemplified as substituted and unsubstituted monovalent hydrocarbon groups having one to forty carbon atoms, such as alkyl groups, such as methyl, ethyl, propyl, butyl, pentyl, and hexyl; aryl groups, such as phenyl, tolyl, and xylyl; aralkyl groups, such as benzyl and phenethyl; and haloalkyl groups, such as 3-chloropropyl and 3,3,3-trifluoropropyl. Methyl and phenyl are particularly useful.

[0037] Alkenyl-dextended polyorganosiloxanes can have straight-chain, partially branched straight-chain, branched, or network molecular structures, or mixtures of such structures. Examples of alkenyl-dextended polyorganosiloxanes include vinyl-terminated polydimethylsiloxanes; vinyl-terminated dimethylsiloxane-diphenylsiloxane copolymers; vinyl-terminated dimethylsiloxane-methylphenylsiloxane copolymers; vinyl-terminated dimethylsiloxane-methylphenylsiloxane-diphenylsiloxane copolymers; vinyl-terminated dimethylsiloxane-methylphenylsiloxane copolymers; vinyl-terminated dimethylsiloxane-methylvinylsiloxane copolymers; vinyl-terminated methylvinylsiloxane-methylphenylsiloxane copolymers; vinyl... End-capped dimethylsiloxane-methylvinylsiloxane-methylphenylsiloxane copolymers; dimethylvinylsiloxy-terminated methylvinylpolysiloxanes; dimethylvinylsiloxy-terminated methylvinylphenylsiloxanes; dimethylvinylsiloxy-terminated dimethylvinylsiloxane-methylvinylsiloxane copolymers; dimethylvinylsiloxy-terminated dimethylsiloxane-methylphenylsiloxane copolymers; dimethylvinylsiloxy-terminated dimethylsiloxane-diphenylsiloxane copolymers; dimethylvinylsiloxy-terminated dimethylsiloxane-diphenylsiloxane copolymers; or combinations thereof. In one particular aspect, alkenyl-dextrin-terminated polyorganosiloxanes include vinyl-dextrin-terminated polydimethylsiloxanes.

[0038] The viscosity of the alkenyl-dextended polyorganosiloxane can be from 100 centipoise (cP) to 150,000 cP. In one aspect, the viscosity of the alkenyl-dextended polyorganosiloxane can be greater than 10,000 cP, preferably from 50,000 cP to 150,000 cP. In a particular aspect, the alkenyl-dextended polyorganosiloxane comprises a vinyl-dextended polydimethylsiloxane with a viscosity greater than 10,000 cP, preferably from 50,000 cP to 150,000 cP.

[0039] In one aspect, the alkenyl-dextended polyorganosiloxane may comprise more than one alkenyl-dextended polyorganosiloxane, such as at least two alkenyl-dextended polyorganosiloxanes. In a particular aspect, the alkenyl-dextended polyorganosiloxane may comprise a first alkenyl-dextended polyorganosiloxane with a viscosity greater than 10,000 cP, preferably from 50,000 cP to 150,000 cP, and a second alkenyl-dextended polyorganosiloxane with a viscosity less than or equal to 10,000 cP, preferably from 100 cP to 500 cP. The first alkenyl-dextended polyorganosiloxane may be a first vinyl-dextended polydimethylsiloxane, preferably a first vinyl-dextended polydimethylsiloxane. The second alkenyl-dextended polyorganosiloxane may be a second vinyl-dextended polydimethylsiloxane, preferably a second vinyl-dextended polydimethylsiloxane.

[0040] Based on the total weight of the curable composition, the alkenyl-dextended polyorganosiloxane may be present in the curable composition in an amount from 30% to 75% by weight. Within this range, the alkenyl-dextended polyorganosiloxane may be present in the curable composition in an amount from 35% to 68% by weight, or 35% to 65% by weight, or 38% to 65% by weight, or 40% to 45% by weight, each based on the total weight of the curable composition.

[0041] The alkenyl-containing compositions of the curable composition further comprise alkenyl-substituted MQ polyorganosiloxanes. As used herein, "MQ polyorganosiloxane" refers to a polyorganosiloxane represented by the following formula:

[0042] ,

[0043] Where the subscripts a, b, c, and d are zero or positive integers, and follow these restrictions: if subscripts a and b are both equal to zero, then subscript c is greater than or equal to two; M´ has the formula R3SiO 1 / 2 ;D´ has the formula R2SiO 2 / 2 ;T´ has the formula RSiO 3 / 2 ; and Q´ has the formula SiO 4 / 2 Each R group independently represents hydrogen, and the terminally substituted C... 1-6The alkenyl, substituted, and unsubstituted monovalent hydrocarbon groups each having one to forty, or one to six, carbon atoms, are subject to the following restriction: at least one, for example, at least two, of the R groups are alkenyl R groups. Preferably, the subscripts a and d are not zero. Suitable alkenyl R groups are exemplified as vinyl, allyl, 1-butenyl, 1-pentenyl, and 1-hexenyl, with vinyl being particularly useful. The alkenyl group can be bonded at the end of the molecular chain, at a dangling position on the molecular chain, or both. In one particular aspect, the alkenyl-substituted MQ polyorganosiloxane is a vinyl-substituted MQ polyorganosiloxane.

[0044] In one aspect, the viscosity of the alkenyl-substituted MQ polyorganosiloxane can be greater than 500 cP, for example greater than 1,000 cP, or greater than 5,000 cP, or greater than 10,000 cP. In a particular aspect, the viscosity of the alkenyl-terminated polyorganosiloxane can be from 5,000 cP to 20,000 cP, or from 10,000 cP to 20,000 cP.

[0045] Based on the total weight of the curable composition, the alkenyl-substituted MQ polyorganosiloxane may be present in the curable composition in an amount from 0.5% to 5% by weight. Within this range, the alkenyl-substituted MQ polyorganosiloxane may be present in amounts from 0.5% to less than 5% by weight, or from 0.5% to 4% by weight, or from 0.5% to 3.5% by weight, or from 0.5% to 3% by weight, or from 0.5% to 2.5% by weight, or from 1% to 2.5% by weight, each based on the total weight of the curable composition.

[0046] The alkenyl-containing component of the curable composition further comprises an alkenyl-substituted copolysiloxane. Suitable alkenyl-substituted copolysiloxanes are typically represented by the following formula:

[0047] ,

[0048] Where the subscripts a, b, c, and d are zero or positive integers, and follow these restrictions: if subscripts a and b are both equal to zero, then subscript c is greater than or equal to two; M´´ has the formula R3SiO 1 / 2 ;D´´ has the formula R2SiO 2 / 2 ;T´´ has the formula RSiO 3 / 2 ; and Q´´ has the formula SiO 4 / 2 Each R group independently represents hydrogen, and the terminally substituted C... 1-6The alkenyl, substituted, and unsubstituted monovalent hydrocarbon groups each having one to forty, or one to six, carbon atoms, are subject to the following restriction: at least one, for example, at least two, of the R groups are alkenyl R groups. Suitable alkenyl R groups are exemplified as vinyl, allyl, 1-butenyl, 1-pentenyl, and 1-hexenyl, with vinyl being particularly useful. The alkenyl group can be bonded at the end of the molecular chain, at a dangling position on the molecular chain, or both. Preferably, the alkenyl-substituted copolysiloxane is an alkenyl-double-terminated polysiloxane that also contains an alkenyl group at a dangling position on the molecular chain. For example, the alkenyl-substituted copolysiloxane can comprise a vinyl-terminated polydimethylsiloxane having vinyl side groups along the polymer chain.

[0049] In one aspect, the alkenyl content of the alkenyl-substituted copolysiloxane can be higher than that of the alkenyl-double-terminated polysiloxane. For example, the vinyl content of the alkenyl-substituted copolysiloxane can be from 0.001 to 5 wt%, or 0.1 to 4 wt%, or 0.5 to 4 wt%, or 1 to 4 wt%, or 2 to 3 wt%, each based on the total weight of the alkenyl-substituted copolysiloxane.

[0050] In one aspect, the viscosity of the alkenyl-substituted copolysiloxane can be less than 1,000 cP, preferably from 100 cP to 500 cP.

[0051] Based on the total weight of the curable composition, the alkenyl-substituted copolysiloxane may be present in the curable composition in an amount from 0.1 to 5% by weight. Within this range, the alkenyl-substituted copolysiloxane may be present in the curable composition in an amount from 0.5 to 5%, or from 0.5 to 2.5%, or from 0.5 to 2%, or from 0.5 to 1.5% by weight, each based on the total weight of the curable composition.

[0052] In one aspect, the alkenyl-containing component of the curable composition may optionally also comprise a monoalkenyl-terminated polyorganosiloxane. A suitable monoalkenyl-terminated polyorganosiloxane can be represented by the following formula:

[0053] ,

[0054] Where the subscripts a, b, c, and d are zero or positive integers, and follow these restrictions: if subscripts a and b are both equal to zero, then subscript c is greater than or equal to two; M´´´ has the formula R3SiO 1 / 2 ;D´´´ has the formula R2SiO 2 / 2 ;T´´´has the formula RSiO 3 / 2; and Q´´´ has the formula SiO 4 / 2 Each R group independently represents hydrogen, and the terminally substituted C... 1-6 Alkenyl, substituted, and unsubstituted monovalent hydrocarbon groups each having one to forty, or one to six, carbon atoms, are subject to the following restriction: at least one, for example, at least two, of the R groups are alkenyl R groups. Suitable alkenyl R groups are exemplified as vinyl, allyl, 1-butenyl, 1-pentenyl, and 1-hexenyl, with vinyl being particularly useful. In monoalkenyl-terminated polyorganosiloxanes, only one end of the polyorganosiloxane contains an alkenyl group. In one aspect, monoalkenyl-terminated polyorganosiloxanes include monovinyl-terminated polyorganosiloxanes, wherein the vinyl group is a group having the formula -CH=CH2, and "substituted vinyl" has the formula -CH=CR2, wherein the R group can independently be hydrogen or C. 1-6 Alkyl groups. The vinyl concentration in the monoalkenyl-terminated polyorganosiloxane can be, for example, from 0.001 to 1 wt%, or from 0.01 to 0.5 wt%, or from 0.01 to 0.25 wt%, or from 0.05 to 0.2 wt%, each based on the total weight of the monoalkenyl-terminated polyorganosiloxane. The viscosity of the monoalkenyl-terminated polyorganosiloxane can be less than 1,000 cP, preferably from 100 cP to 750 cP.

[0055] When present, the monoalkenyl-terminated polyorganosiloxane may be included in the curable composition in an amount from 0.5% to 5% by weight, based on the total weight of the curable composition. Within this range, the monoalkenyl-terminated polyorganosiloxane may be included in the curable composition in an amount from 0.5% to 3% by weight, or from 0.75% to 2.75% by weight, or from 1% to 2.5% by weight, each based on the total weight of the curable composition.

[0056] In addition to the alkenyl-containing component, the curable composition also contains a hydrogen-containing component. The hydrogen-containing component comprises hydrogen-substituted polyorganosiloxanes.

[0057] Hydrogen-substituted polyorganosiloxanes can have at least two silicon-bonded hydrogen atoms per molecule, and are typically represented by the following formula:

[0058]

[0059] Where the subscripts a, b, c, and d are zero or positive integers, and follow these restrictions: if subscripts a and b are both equal to zero, then subscript c is greater than or equal to two; M´´´´ has the formula R3SiO 1 / 2 ;D´´´´ has the formula R2SiO 2 / 2 ;T´´´´has the formula RSiO 3 / 2; and Q´´´´ has the formula SiO 4 / 2 Each R group independently represents hydrogen, a substituted and an unsubstituted monovalent hydrocarbon group having one to forty or one to six carbon atoms, subject to the following restriction: at least two of the R groups are hydrogen. For example, each of the R groups in a polyorganosiloxane having at least two silicon-bonded hydrogen atoms per molecule is independently selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, aryl, phenyl, tolyl, xylyl, aralkyl, benzyl, phenethyl, haloalkyl, 3-chloropropyl, 3,3,3-trifluoropropyl, or combinations thereof. Methyl and phenyl may be preferred.

[0060] Hydrogen can be bonded to silicon at the ends of the molecular chain, at overhanging positions on the molecular chain, or both. In one aspect, hydrogen is substituted at the end positions. In one aspect, at least 3 to 4 hydrogen atoms are present per molecule. The hydrogen-containing polyorganosiloxane component can have a straight-chain, partially branched straight-chain, branched, cyclic, or network molecular structure, or can be a mixture of two or more different polyorganosiloxanes having the illustrated molecular structures.

[0061] Hydrogen-containing polyorganosiloxanes may include, for example, trimethylsiloxy-terminated methylhydropolysiloxanes; trimethylsiloxy-terminated dimethylsiloxane-methylhydrosiloxane copolymers; trimethylsiloxy-terminated methylhydrosiloxane-methylphenylsiloxane copolymers; trimethylsiloxy-terminated dimethylsiloxane-methylhydrosiloxane-methylphenylsiloxane copolymers; dimethylhydrosiloxy-terminated dimethylpolysiloxanes; dimethylhydrosiloxy-terminated methylhydropolysiloxanes; dimethylhydrosiloxy-terminated dimethylsiloxane-methylhydrosiloxane copolymers; dimethylhydrosiloxy-terminated dimethylsiloxane-methylphenylsiloxane copolymers; and dimethylhydrosiloxy-terminated methylphenylpolysiloxanes. In one particular aspect, hydrogen-substituted polyorganosiloxanes include trimethylsiloxy-terminated methylhydropolysiloxanes.

[0062] In one aspect, the silicon-containing component may comprise silicon-bonded hydrogen atoms and an alkenyl group. In another aspect, the alkenyl group may be a vinyl group and may be located at the end of the chain of the silicon-containing component.

[0063] The hydride-containing component may have a hydrogen content ranging from 0.01 wt% to 10 wt% and a viscosity at 25°C ranging from 10 centipoise to 10,000 centipoise. In one particular aspect, the hydrogen-substituted polyorganosiloxane comprises a trimethylsiloxy-terminated methylhydropolysiloxane with a hydrogen content ranging from 0.1 wt% to 5 wt%, or 0.5 wt% to 2 wt%, or 1 wt% to 2 wt%. In another particular aspect, the hydrogen-substituted polyorganosiloxane comprises a trimethylsiloxy-terminated methylhydropolysiloxane with a viscosity ranging from 10 cP to 50 cP, or 10 cP to 30 cP, or 15 cP to 30 cP, or 20 cP to 30 cP. In yet another specific aspect, hydrogen-substituted polyorganosiloxanes include trimethylsiloxy-terminated methylhydropolysiloxanes having a hydrogen content of 0.1 to 5 wt%, or 0.5 to 2 wt%, or 1 to 2 wt%, and a viscosity of 10 cP to 50 cP%, or 10 cP to 30 cP%, or 15 cP to 30 cP%, or 20 cP to 30 cP. In yet another specific aspect, hydrogen-substituted polyorganosiloxanes comprise a hydrogen content of 0.01 to 1 wt%, or 0.01 to 0.1 wt%, or 0.01 to 0.05 wt%, a vinyl content of 0.1 to 1 wt%, or 0.1 to 0.5 wt%, or 0.2 to 0.8 wt%, and a viscosity of 10 cP to 500 cP%, or 50 cP to 400 cP%, or 100 cP to 300 cP. - Monovinyl- - Hydrogen-terminated polydimethylsiloxane.

[0064] This disclosure also considers combinations of hydrogen-containing polyorganosiloxanes.

[0065] The hydrogen-substituted polyorganosiloxane component is used in an amount sufficient to cure the composition, for example, in an amount providing a molar ratio of 1.1 to 2.5, or 1.1 to 1.5, of hydrogen groups relative to the sum of vinyl and hydroxyl groups.

[0066] In one aspect, the hydrogen-substituted polyorganosiloxane component can provide a carrier liquid. The carrier liquid is preferably a polyorganosiloxane, for example, having the following structure.

[0067] ,

[0068] Wherein M, D, T, Q, and subscripts a, b, c, and d are as previously defined. In one aspect, the carrier liquid may comprise a second alkenyl-terminated polyorganosiloxane, which may be the same as or different from the previously described alkenyl-terminated polyorganosiloxanes. For example, the second alkenyl-terminated polyorganosiloxane may differ from the previously described alkenyl-terminated polyorganosiloxanes in terms of chemical composition, viscosity, or both. In one aspect, the second alkenyl-terminated polyorganosiloxane may differ from the previously described alkenyl-terminated polyorganosiloxanes in terms of viscosity. Preferably, the second alkenyl-terminated polyorganosiloxane is an alkenyl-dual-terminated polyorganosiloxane, wherein both of the chain ends are alkenyl. As used herein, vinyl refers to a group having the formula -CH=CH2, and "substituted vinyl" refers to a group having the formula -CH=CR2, wherein the R group may independently be hydrogen or C. 1-6 Alkyl. The vinyl concentration in the second alkenyl-terminated polyorganosiloxane may be, for example, 0.001 to 1 wt%, or 0.01 to 0.5 wt%, or 0.01 to 0.15 wt%, or 0.01 to 0.1 wt%, each based on the total weight of the second alkenyl-terminated polyorganosiloxane.

[0069] In one aspect, the carrier liquid may comprise a second alkenyl-terminated polyorganosiloxane with a viscosity greater than 500 cP, for example greater than 1,000 cP, or greater than 5,000 cP. In a particular aspect, the viscosity of the second alkenyl-terminated polyorganosiloxane may be from 500 cP to 10,000 cP.

[0070] When contained in a carrier liquid, the hydrogen-substituted polyorganosiloxane component may be present in the carrier liquid in a weight ratio of 10:90 to 90:10, or 50:50 to 85:15, or 60:40 to 70:30.

[0071] In addition to alkenyl-containing and hydrogen-containing components, the curable composition also includes a curing catalyst, a filler composition, a foaming agent, and optional inhibitors.

[0072] The curing catalyst can be a catalyst for the hydrosilylation reaction. An effective catalyst promotes the addition of hydrogen to the alkenyl multiple bonds of silicon bonds to accelerate curing. Such catalysts can include noble metals, such as platinum, rhodium, palladium, ruthenium, iridium, or combinations thereof. The catalyst can also include a support material, such as activated carbon, alumina, silica, polymer resins, or combinations thereof.

[0073] In one aspect, the curing catalyst may be present in an amount up to 1,000 parts per million by weight (ppmw) of the metal (e.g., platinum). In another aspect, the curing catalyst may be present in an amount of 1 ppmw to 500 ppmw, or 1 ppmw to 250 ppmw, or 1 ppmw to 100 ppmw, or 1 ppmw to 50 ppmw, or 5 ppmw to 50 ppmw, or 10 ppmw to 50 ppmw.

[0074] Platinum and platinum-containing compounds are preferred, including, for example, platinum black, platinum on alumina powder, platinum on silica powder, platinum on carbon powder, chloroplatinic acid, alcoholic solutions of platinum chloroplatinic acid-olefin complexes, platinum-alkenylsiloxane complexes, and catalysts provided by the micronization of a dispersion of the catalyst in polymer resins such as methyl methacrylate, polycarbonate, polystyrene, silicone, etc. Combinations of different catalysts can also be used. When using a platinum catalytic system, catalyst poisoning may occur, which can result in the formation of uncured or poorly cured silicone compositions with low strength. Additional platinum can be added, but when large amounts of platinum are added to improve curing, the pot life or working time may be adversely affected. Methyl vinyl (MviMvi) components can be used as curing inhibitors, such as 1-2287 curing inhibitor from Dow Corning. Such materials bind platinum at room temperature to prevent curing and thus improve working time, but release platinum at higher temperatures to affect curing for the desired time period. The levels of platinum and curing inhibitors can be adjusted to change the curing time and working time / pot life. When using higher platinum levels, the concentration is typically less than or equal to 100 ppmw based on the total weight of the curable polysiloxane composition. Within this range, an additional platinum concentration (i.e., exceeding the required amount) may be greater than or equal to 50 ppmw or greater than or equal to 60 ppmw based on the total weight of the curable composition. Furthermore, within this range, an additional platinum concentration may be less than or equal to 90 ppmw or less than or equal to 80 ppmw based on the total weight of the curable composition.

[0075] The concentration of the curing retarder (if a curing retarder is used) is less than or equal to 0.3% by weight (wt%) of the total curable polysiloxane composition. Within this range, the concentration of the curing retarder is greater than or equal to 0.005% by weight, or greater than or equal to 0.025% by weight, based on the total weight of the curable polysiloxane composition. Furthermore, within this range, the concentration of the curing retarder is less than or equal to 0.2% by weight, or less than or equal to 0.1% by weight, based on the total weight of the curable composition and the required working time or pot life.

[0076] Figure 1One aspect is shown, in which the thermal management sheet 10 includes a compressible silicone foam layer 12 having a first outer surface 14 and an opposite second outer surface 16. Although shown as flat, one or both or all of the outer surfaces may be undulating to provide a better fit with the surface of the electrochemical single cell.

[0077] The compressible silicone foam layer 12 also includes a plurality of openings, namely pores 18. The pores are defined by the inner surface 20 of the compressible foam. The pores can be interconnected or discrete. A combination of interconnected and discrete pores can exist. The pores can be completely contained within the sheet, or at least a portion of the pores can be open to the surface of the sheet, thereby allowing communication with the surrounding environment. In one aspect, at least a portion of the pores are interconnected and at least a portion of the pores are open, thereby allowing air, water, water vapor, etc., to pass from the first outer surface 14 to the opposite second outer surface 16, referred to herein as "open-cell foam". In another aspect, the foam can be "closed-cell foam", wherein the pores may be interconnected or may not be interconnected, and are substantially not open to the surface of the sheet, or are completely closed, such that the sheet does not allow air, water, water vapor, etc., to pass in large quantities from one outer surface to another. In one aspect, the foam is a substantially closed-cell foam, or a completely closed-cell foam.

[0078] Further reference Figure 1 The filler composition may comprise a filler composition, such as two or more different fillers 22, 24 distributed within the compressible silicone foam layer 12. In one aspect, the filler composition may comprise a single filler 22 distributed within the compressible silicone foam layer 12. The filler may be distributed substantially uniformly or as a gradient distribution, for example, increasing in the direction from the first outer surface 14 to the second outer surface 16. As used herein, the phrase "contained within" may mean that the filler composition is distributed within the matrix of the silicone foam layer, such as... Figure 1 As shown. Furthermore, as used herein, the phrase “located within” can mean that the filler composition can be located within the pores 18 of the silicone foam layer, for example, on the inner surface 20 of a coated flexible foam material, or in a granular form within the pores. A portion of the pores in the silicone foam layer may contain the filler composition, or substantially all or all of the pores may contain the filler composition. Each pore containing the filler composition can be independently partially filled, substantially completely filled, or completely filled.

[0079] The filler is preferably in granular form to allow for easy incorporation into the silicone foam during its manufacture. As described above, the filler composition in granular form can be located within the silicone matrix of the silicone foam layer, within the pores of the silicone foam layer, or both. A portion of the pores in the silicone foam layer may contain the filler composition, or substantially all or all of the pores may contain the filler composition. Each pore containing the filler composition can be independently partially filled, substantially completely filled, or completely filled. In aspects where the particle size of the filler composition is large relative to the diameter of the pore, or where the pore is substantially or completely filled by a plurality of smaller particles, particle movement within the pore can be restricted. In this respect, the filler composition can be located in the pores during the manufacture of the layer (e.g., by including the filler composition in the composition used to form the silicone foam layer), or the filler composition can be impregnated into the pores after the manufacture of the silicone foam layer using a suitable liquid carrier, vacuum, or other known methods.

[0080] Different filler compositions (including combinations of different types, forms, or arrangements) can be used. For example, a filler composition in particulate form within the pores of a silicone foam layer can be used in combination with a filler composition distributed within the silicone foam layer.

[0081] The filler can be in the form of a granular material. The particles can be any irregular or regular shape, such as approximately spherical, disc-shaped, fibrous, flake, sheet, rod (solid or hollow), spherical (solid or hollow), or whisker. An important characteristic is that the maximum size of most, substantially all, or all of the particles is smaller than the thickness of the layer or pore in which they reside, to provide a smooth surface for the layer. Therefore, the specific diameter used depends on the location of the particles. A bimodal, trimodal, or even higher multimodal distribution of the particles can be used. For example, a bimodal distribution of particles can exist when the filler particles are present within the matrix of a silicone foam layer and within the pores of the silicone foam layer. A multimodal distribution can be the result of using two different granular materials or a single material having two or more size modes. In one aspect, the median diameter of each of the granular fillers (which, as defined herein, may mean the equivalent spherical diameter) can be from 0.1 micrometers (µm) to 1 millimeter (mm), or from 0.5 µm to 500 µm, or from 1 µm to 50 µm.

[0082] In one aspect, the filler composition can be a reactive filler composition comprising at least one reactive filler. As will be understood from the following discussion, the term "reactive" as used in conjunction with the filler composition includes both chemical reactions and physical processes (e.g., hydrogen bond breaking and formation). The type and amount of the reactive filler composition can be selected first to produce water upon exposure to heat. As used herein, "producing water" can mean, for example, releasing water from a hydrate, or forming water, for example, through a chemical reaction process. Furthermore, the produced water can be in the form of a liquid or water vapor. As used herein, therefore, "water" includes liquid water, water vapor, or a combination thereof. As used herein, "heat" means heat above the typical operating temperature of the battery and includes heat generated by or in contact with a flame. Such temperatures can be 200°C or higher, or 300°C or higher, or 500°C or higher. Without being bound by theory, it is thought that the water produced by the reactive filler composition can provide thermal barrier properties by absorbing heat, redistributing heat, or by the evaporation of water.

[0083] In one aspect, the type and amount of each reactive filler can also be selected to form a thermal barrier layer in situ upon exposure to heat, absorb water, or both. As used herein, a “thermal barrier layer” is a layer that is physically, chemically, or both physically and chemically different from the thermal management sheet, and that can provide a conductive or convective thermal barrier against heat, flame, or both. A “thermal barrier layer” includes a carbon layer (as may be used in the art) or a water-swellable polymer.

[0084] Exemplary reactive fillers may include aluminum trihydrate (also known as aluminum trihydride or ATH), ammonium nitrate, sodium borate, hydrated sodium silicate, magnesium hydroxide, basic magnesium carbonate pentahydrate, magnesium trihydrate octahydrate, zinc borate, superabsorbent polymers, or water glass. Sodium borate may be obtained from manufacturers such as SAE Manufacturing Specialties Corp., Surepure Chemetals, Inc., Mil-Spec Industries, Noah Chemicals, ProChem, Inc., Rose Mill Co., US Borax, Quality Borate, and BariteWorld. Zinc borate may be obtained from manufacturers such as SAE Manufacturing Specialties Corp., Surepure Chemetals, Inc., Mil-Spec Industries, Noah Chemicals, ProChem, Inc., Rose Mill Co., US Borax, Quality Borate, and BariteWorld. ATH is available from manufacturers such as SAE Manufacturing Specialties Corp., Surepure Chemetals, Inc., Mil-Spec Industries, USALCO, LLC, Cimbar Performance Metals, Huber Engineered Materials, LKAB Minerals, MarkeTech International, RJ Marshall Company, Aluchem, and Alcan Chemicals.

[0085] In one aspect, the thermal management sheet comprises at least two fillers with specific properties. In another aspect, the reactive filler composition may comprise at least two of aluminum trihydrate, ammonium nitrate, sodium borate, hydrated sodium silicate, magnesium hydroxide, basic magnesium carbonate pentahydrate, magnesium triphosphate octahydrate, zinc borate, superabsorbent polymer, or water glass. It should be understood that hydrated mineral fillers and water glass may be represented by different chemical formulas, and the foregoing includes various molecular formulas. Certain hydrated mineral fillers known as phase change materials (which release water at lower temperatures, e.g., below 100°C or below 200°C) are not used to prevent phase change at normal operating temperatures.

[0086] Fillers that can participate in the formation of a thermal barrier layer, absorb water, or both include various sodium-, silicon-, and boron-containing mineral fillers. A single filler can both generate water and participate in the formation of a thermal barrier layer. Exemplary fillers of this type may include ATH, ammonium nitrate, sodium borate, hydrated sodium silicate, magnesium hydroxide, basic magnesium carbonate pentahydrate, magnesium triphosphate octahydrate, zinc borate, superabsorbent polymers, or combinations thereof.

[0087] In one particular aspect, the reactive filler composition may comprise aluminum trihydrate and zinc borate. This combination can generate water upon exposure to a heat source. The water can cause the silicone foam to expand, providing back pressure. Without being bound by theory, the generated water can absorb heat to delay or prevent thermal runaway. Additional heat can be absorbed through the conversion of liquid water to water vapor. The heat capacity of ATH and zinc borate can further contribute to heat absorption. A porous thermal barrier layer can form upon exposure to a heat source.

[0088] In another aspect, a first and second filler are selected to both generate water and form a borosilicate glass thermal layer in situ upon exposure to heat. In this aspect, the first and second fillers may comprise a combination of sodium borate and hydrated sodium silicate. Sodium borate and hydrated sodium silicate can generate water and provide sodium and boron to form borosilicate glass. The decomposition of the flexible silicon layer can provide silicon to form borosilicate glass. Furthermore, in this aspect, a combination of ATH, zinc borate, and hydrated sodium silicate can be used. Without being bound by theory, it is considered that during exposure to a heat source, the heat generated by the water from both organosilicon and sodium borate, and any heat of evaporation, as well as the heat absorbed by the endothermic formation of borosilicate glass, can compress the organosilicon foam to absorb heat. A thermal barrier layer can form and expand upon exposure to a heat source.

[0089] In one aspect, a combination of sodium borate and zinc borate can be used in reactive filler compositions. The borosilicate glass thermal barrier layer produced by this combination can both expand and deform to form a flexible yet rigid layer. The deformation can act as a normal force against adjacent expanding cell cells, which can reduce or prevent damage from expanding cell cells that have already entered thermal runaway. Unbound by theory, it is thought that the normal force generated by the expansion pressure, along with the shape of the carbon layer, can further impede convective and conductive heat transfer.

[0090] In these aspects, the composition and concentration of the reactive filler composition can be selected to provide a staged release of water, thereby providing continuous heat reduction. For example, it has been found that during hot plate tests of filler compositions containing a combination of sodium borate and zinc borate, heat from the hot plate diffuses into the flexible foam and generates water vapor in multiple stages, for example, first by sodium borate at 140°C and then by zinc borate at 340°C. Again, not bound by theory, it is considered that the initial release of water from sodium borate initiates and sustains the formation of the thermal barrier layer and affects the thickness of the final borosilicate glass thermal barrier layer, and thus affects the applied pressure. The process also absorbs heat due to the heat capacity of the silicone, zinc borate, and sodium borate, the heat generated by water from both zinc borate and sodium borate, and any heat of evaporation, as well as the endothermic formation of the borosilicate glass. Furthermore, deformation of the filled foam layer can provide resistance to heat transfer.

[0091] In another example of phased water release, a reactive filler composition comprising sodium borate and aluminum trihydrate can first generate water vapor from sodium borate at 140°C, and then generate water vapor from the decomposition of ATH at 220°C.

[0092] Another reactive filler composition that can provide staged water release may comprise sodium borate, ATH, and zinc borate. This composition can provide a three-stage water production system that produces water at 140°C from sodium borate, at 220°C from ATH, and at 340°C from zinc borate.

[0093] In one aspect, the reactive packing composition can be further formulated to absorb water that can be captured or released (recycled). In this aspect, water absorption provides an additional mechanism to delay, reduce, or prevent convective heat transfer. Water absorption can further contribute to expansion to provide additional pressure reduction. In this aspect, the reactive packing composition includes a packing that generates water when exposed to heat and a packing that can absorb the generated water. The water can be permanently absorbed (i.e., captured) or releasably absorbed (desorbed), thereby allowing water recycling.

[0094] In this respect, the filler material that generates water may include sodium borate, zinc borate, ATH, magnesium hydroxide pentahydrate (MDH), or a combination thereof.

[0095] Packing materials that can absorb the generated water include superabsorbent polymers (SAP). Under some conditions, SAP absorbs and traps water, where the trapped water is released only through the breakdown of the SAP. Under other conditions, SAP can absorb water and release it without the breakdown of the SAP. Superabsorbent polymers are known in the art, such as hydrolyzed products of starch grafted with acrylonitrile homopolymers or copolymers, e.g., hydrolyzed starch-polyacrylonitrile; starch grafted with acrylic acid, acrylamide, polyvinyl alcohol (PVA) or combinations thereof, e.g., starch-g-poly(2-acrylamide-copoly-2-acrylic acid, sodium salt); hydrolyzed starch-polyacrylonitrile ethylene-maleic anhydride copolymer; crosslinked carboxymethyl cellulose; acrylate homopolymers and copolymers thereof, e.g., poly(sodium acrylate) and poly(acrylate-copoly-acrylamide), specifically, poly(sodium acrylate-copoly-acrylamide); hydrolyzed acrylonitrile homopolymers; homopolymers and copolymers of 2-acrylic acid, e.g., poly(2-acrylic acid, sodium salt) and poly(2-acrylamide-copoly-2-acrylic acid, sodium salt) or poly(2-acrylamide-copoly-2-acrylic acid, potassium salt); crosslinked modified polyacrylamide; polyvinyl alcohol copolymers, crosslinked polyethylene oxide; and so on. Combinations of two or more different SAPs can be used.

[0096] SAP is preferably an electrolyte, such as a salt of poly(acrylate), for example, poly(sodium acrylate). The swelling ratio of SAP can be from 15:1 to 1000:1. A higher ratio is preferred. Upon absorbing water, SAP traps water and expands. The expansion can act as a normal force against adjacent expanded cell cells, which can reduce or prevent damage from expanded cell cells that have already entered thermal runaway.

[0097] SAP can optionally be hydrated in water (by spraying, immersion or other methods). For example, SAP can be hydrated before being incorporated into silicone foam, or silicone foam containing SAP can be immersed in water at room temperature for 24 hours.

[0098] Unbound by theory, it is assumed that in this aspect, as described above, water is initially generated by the filler as the temperature increases (optionally at multiple temperatures). The water is absorbed by the SAP. In one aspect, the water absorbed by the SAP is trapped and not released. In another aspect, the water absorbed by the SAP absorbs heat and is then released, leaving the system including electrochemical single-cell batteries, or is absorbed by other dehydrated SAPs at different locations within the silicone foam. Ultimately, the borosilicate glass can be formed as a continuous and flexible thermal barrier layer.

[0099] Another filler that can be used to absorb water is water glass. As is known in the art, water glass is soluble in water and contains sodium oxide (Na₂O) and silicon dioxide (silica, SiO₂). Under certain conditions, water glass can absorb water to capture it, or absorb water and release it.

[0100] In another aspect, reactive filler compositions can be formulated to produce water glass in situ without decomposition of the flexible silicone layer. In this aspect, the filler may include sodium borate and hydrated sodium silicate. Other components may be present, such as aluminum trihydrate, magnesium hydroxide, basic magnesium carbonate pentahydrate, or ammonium nitrate, or combinations thereof. Without being bound by theory, it is assumed that heat diffuses into the silicone foam, producing water at various temperatures depending on the combination of water-producing fillers used. Residual ions from the decomposition of the water-producing filler may form Lewis acids or Lewis bases and react with hydrated sodium silicate to form water glass. The water can be released for recycling. Alternatively, the water glass solution may solidify to provide a glassy solid that can serve as a heat transfer barrier layer inside or outside the silicone foam when the water evaporates due to heating.

[0101] In one aspect, the filler composition may comprise a non-reactive filler. As used herein, the term "non-reactive filler" means a filler that does not participate in chemical reactions or physical processes (such as hydrogen bond breaking and formation). Exemplary "non-reactive fillers" may include, but are not limited to, expanded perlite, unexpanded perlite, glass beads, vermiculite, expanded vermiculite, expanded glass, zeolite, aerogel, silica, porous silica, porous alumina, mica, cork, glass fiber, microspheres, potassium titanate whiskers, or combinations thereof.

[0102] The filler composition may be present in the curable composition in an amount from 10% to 70% by weight, based on the total weight of the curable composition. Within this range, the filler composition may be present in an amount from 20% to 60% by weight, or from 20% to 50% by weight, each based on the total weight of the curable composition.

[0103] The curable composition further comprises a foaming agent. In one aspect, the foaming agent includes a chemical foaming agent. For example, in one aspect, the foaming agent may comprise water, a silanol-terminated polyorganosiloxane, and C... 1-12 Monohydric alcohols (including diols, triols, etc.). The viscosity of silanol-terminated polyorganosiloxanes can be from 20 cP to 40,000 cP, or from 400 cP to 2,000 cP, or from 500 cP to 1,000 cP. In one particular aspect, the silanol-terminated polyorganosiloxanes include hydroxyl-terminated polydimethylsiloxanes. In one aspect, the alcohol preferably includes C... 1-6 Alcohols. In one particular aspect, alcohols include 1-butanol. In another aspect, alcohols can consist of monohydric alcohols.

[0104] Suitable blowing agents may also include physical blowing agents. Exemplary physical blowing agents include hydrogen-containing components that can be used alone, as a mixture of each other, or with another type of blowing agent. These blowing agents can be selected from a wide range of substances, including hydrocarbons; ethers; esters, and partially halogenated hydrocarbons, ethers, and esters. Examples of physical blowing agents have boiling points of -50°C to 100°C, or -50°C to 50°C. Among them, hydrogen-containing blowing agents are HCFCs (halochlorofluorocarbons), such as 1,1-dichloro-1-fluoroethane, 1,1-dichloro-2,2,2-trifluoroethane, monochlorodifluoromethane, and 1-chloro-1,1-difluoroethane; HFCs (halo fluorocarbons (halogenated fluorocarbons), such as 1,1,1,3,3,3-hexafluoropropane, 2,2,4,4-tetrafluorobutane, 1,1,1,3,3,3-hexafluoro-2-methylpropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2,2-pentafluoropropane, 1,1,1,2,3-pentafluoropropane, 1,1,2,3,3-pentafluoropropane, 1,1 The blowing agent may include 1,3,3,4-hexafluorobutane, 1,1,1,3,3-pentafluorobutane, 1,1,1,4,4,4-hexafluorobutane, 1,1,2,2,3,3-hexafluoropropane, 1,1,1,2,3,3-hexafluoropropane, 1,1-difluoroethane, 1,1,1,2-tetrafluoroethane, (Z)-1,1,1,4,4,4-hexafluoro-2-butene, and pentafluoroethane; HFE (halofluoroether), such as methyl-1,1,1-trifluoroethyl ether and difluoromethyl-1,1,1-trifluoroethyl ether; and hydrocarbons such as n-pentane, isopentane, and cyclopentane. In one aspect, the blowing agent may include carbon dioxide, nitrogen, argon, water, air, nitrogen, and inert gases (e.g., helium and argon), and combinations thereof. In one aspect, the blowing agent may include carbon dioxide, such as solid carbon dioxide (i.e., dry ice), liquid carbon dioxide, gaseous carbon dioxide, or supercritical carbon dioxide.

[0105] Based on the total weight of the curable composition, the blowing agent may be present in the curable composition in a total amount of 0.16 to 2 weight percent, or 0.5 to 2 weight percent. In one particular aspect, the blowing agent includes a chemical blowing agent, and based on the total weight of the curable composition, the chemical blowing agent may be present in the curable composition in a total amount of 0.16 to 2 weight percent, or 0.5 to 2 weight percent. In one aspect, based on the total weight of the curable composition, water may be included in an amount of 0.01 to 0.5 weight percent. In one aspect, based on the total weight of the curable composition, silanol-terminated polyorganosiloxane may be present in an amount of 0.1 to 1 weight percent. In one aspect, based on the total weight of the curable composition, C... 1-12 Monohydric alcohols can be present in amounts from 0.05% to 0.5% by weight.

[0106] The curable composition may optionally contain an inhibitor. Suitable inhibitors for use in the curable composition may include alkenyl-dual-terminated polyorganosiloxanes, which may be represented by the following formula:

[0107] ,

[0108] As discussed above, the alkenyl-dextended polyorganosiloxane inhibitor used as an inhibitor may have a vinyl content greater than or equal to 15% by weight (based on the total weight of the alkenyl-dextended polyorganosiloxane inhibitor), a molecular weight less than 500 g / mol, or both. In one aspect, the inhibitor contains and comprises an alkenyl-dextended polyorganosiloxane having a vinyl content greater than or equal to 15% by weight, for example, 15% to 40% by weight, or 20% to 40% by weight, or 25% to 35% by weight, each based on the total weight of the alkenyl-dextended polyorganosiloxane, and a molecular weight less than 500 g / mol, for example, 50 g / mol to 450 g / mol, or 100 g / mol to 400 g / mol, or 100 g / mol to 250 g / mol.

[0109] When present, the inhibitor may be included in the curable composition in an amount from 0.01 to 0.4% by weight, based on the total weight of the alkenyl-containing and hydrogen-containing components in the curable composition.

[0110] Other additives, such as ultraviolet (UV) stabilizers, antistatic agents, dyes, pigments, antimicrobial agents, or antiviral agents, or combinations thereof, may be present in any part of the curable composition (as discussed herein). When additives are present, the amount used is selected such that the desired properties of the cured silicone composition are not adversely affected by the presence of the additives.

[0111] Curable silicone compositions can be manufactured by combining various components in any suitable order. In one aspect, the curable composition can be provided as a first part and a second part. The first part may contain an alkenyl-containing component, and the second part may contain a hydrogen-containing component. In one aspect, the first part may also contain one or more of a curing catalyst, a filler composition, a foaming agent, and an inhibitor (when present). The first and second parts can be, for example, mixed, metered, or cast into a mold or a continuous coating line to provide compressible silicone foam. Foaming and curing then occur in the mold or on the continuous coating line. In another production method, the reactive components of the curable composition can be introduced into an extruder together with a filler composition and a chemical foaming agent or other additives (if used). A catalyst can then be metered into the extruder to initiate the foaming and curing reaction.

[0112] The alkenyl-containing component and the hydrogen-containing component may be present in the curable composition in an amount that effectively provides an alkenyl-containing component to hydrogen-containing component weight ratio of 10:1 to 40:1, or 13:1 to 40:1, or 13:1 to 25:1, or 13:1 to 20:1. In one aspect, the curable composition may include a molar ratio of hydrogen groups to the sum of alkenyl and hydroxyl groups of 1.1:1 to 2.5:1, or 1.1:1 to 2:1, or 1.1:1 to 1.5:1.

[0113] In one aspect, other components not specifically described herein may be minimized (i.e., present in amounts less than or equal to 5% by weight, or less than or equal to 1% by weight, or less than or equal to 0.5% by weight, or less than or equal to 0.1% by weight, or less than or equal to 0.01% by weight, each based on the total weight of the curable composition) or excluded from the curable composition and the cured silicone foam prepared from the curable composition. For example, the curable composition may optionally minimize or exclude polymers other than the various polysiloxanes described herein. In one aspect, the curable composition may optionally minimize or exclude surfactants such as fluorinated surfactants. The curable composition described herein or the method of manufacturing compressible silicone foam may optionally minimize or exclude physical blowing agents. The curable composition may optionally minimize or exclude insulating fillers.

[0114] A cured silicone foam layer can be formed by casting a curable composition and then curing the cast composition. The inventors have unexpectedly discovered that the curable composition can unexpectedly provide low density in cast silicone foams. Post-curing can be used to advance curing to near-complete states, thereby developing desired physical properties. The cured silicone foams described herein are considered self-supporting silicone foams. As used herein, self-supporting means the absence of a support layer. Therefore, any discussion of specific properties related to cured silicone foams according to this disclosure in the absence of any support layer should be understood as referring to the properties of the foam layer itself.

[0115] A liquid material of a curable composition can be fed into the mixture and cast onto a moving release layer. In one aspect, an additional release layer is pulled over the top of the cast mixture, and then the sandwich mixture is passed through the gap between two rotating rollers to control the amount of the curable composition, which determines the thickness of the partially cured foam and ultimately the thickness of the final foam. The gap thickness between the rollers (i.e., the roller gap) can be adjusted to reduce the thickness of the sandwich mixture as it passes between them. In one aspect, the roller gap can be, for example, 0.005 inches to 0.5 inches (0.127 mm to 12.7 mm), or 0.01 inches to 0.1 inches (0.254 mm to 2.54 mm), or 0.01 inches to 0.05 inches (0.254 mm to 1.27 mm), or 0.02 inches to 0.04 inches (0.508 mm to 1.016 mm). During the conditioning step, the width of the sandwich mixture can be maintained, but the length of the sandwich mixture can be increased as the thickness decreases. In another aspect, a second release layer and rollers are not used on top of the cast mixture, and processes such as knife-over-roll can be used to determine the thickness of the partially cured foam and ultimately the thickness of the final foam.

[0116] The coated release layer is passed through an oven, which may be heated by at least one pressure plate, heated by heated air, or by other means or combinations thereof, to foam and at least partially cure the casting composition. Two or more curing ovens at the same or different temperatures may be used. The temperature in the oven may be from 80°F to 200°F (43.3°C to 60°C), and the residence time of the coated carrier in the oven may be varied to achieve the desired level of curing. After leaving the oven, the additional top layer may be removed when using another top layer of the carrier film.

[0117] It has been found that only certain carriers provide sufficient adhesion to the release layer. Suitable carriers for use with the above-described curing conditions are polyesters (e.g., polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, or polybutylene naphthalate). Polyethylene terephthalate is preferred. Processing conditions can be adjusted to achieve effective adhesion to other release layers such as polyolefins (e.g., polyethylene, polypropylene, or ethylene-propylene copolymers), polyvinyl alcohol, polyvinylidene chloride, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyamides, polyimides, cellulose, fluorinated resins, polyethers, polystyrene resins (e.g., polystyrene), polycarbonates, polyethersulfone, or combinations thereof. In one aspect, the substrate comprises polyethylene terephthalate.

[0118] Foam can be wound on rollers for storage and optional heat / post-curing, for example, for 6 to 48 hours at temperatures ranging from 100°F to 300°F (65.6°C to 121.1°C). Post-curing is particularly useful for reducing compression set, eliminating volatile compounds, and, if necessary, achieving complete curing.

[0119] The silicone foam obtained from the curable composition of this disclosure is a compressible silicone foam. As used herein, the term "foam" refers to a material having a porous structure (i.e., pore contents). The foam produced by this method is predominantly closed-cell. For example, the closed-cell content of the compressible silicone foam can be at least 50% or at least 60%. The pore morphology can be characterized, for example, using various microscopic techniques such as optical microscopy or scanning electron microscopy. The thickness of the silicone foam can be, for example, from 1 mm to 30 mm, or 1 mm to 20 mm, or 1 mm to 15 mm, or 1 mm to 1 mm, or 1 mm to 8 mm, or 1.2 mm to 8 mm, or 1.5 mm to 8 mm, or 1.5 mm to 6 mm, or 2.5 mm to 6 mm. The density of the compressible silicone foam can be less than 400 kg / m³. 3 For example, 150 kg / m 3 to less than 400 kg / m 3 or 150 kg / m 3 Less than 350 kg / m 3 or 200 kg / m 3 Up to 335 kg / m 3 or 250 kg / m 3 Up to 325kg / m 3 Based on the total volume of the foam, the silicone foam can have a void volume content of 5% to 99%, preferably greater than or equal to 30% (i.e., 30% to 99%).

[0120] Compressible silicone foams advantageously maintain their elastic behavior over numerous compression cycles throughout their lifespan; these properties are reflected in the foam's compressive force deflection and compression set. Foams with good resistance to compression set provide cushioning and retain their original shape or thickness under prolonged loads. In one aspect, the respective compression force deflection (CFD) of silicone foams at 25% deformation can be less than 35 kPa, or 5 kPa to less than 35 kPa, or 10 kPa to 33 kPa. The respective CFD of silicone foams at 50% deformation can be less than 100 kPa, or 10 kPa to less than 100 kPa, or 10 kPa to 75 kPa, or 20 kPa to 75 kPa. The respective CFD of silicone foams at 80% deformation can be less than 1000 kPa, or 100 kPa to less than 1000 kPa, or 100 kPa to 800 kPa, or 150 kPa to 800 kPa. The compressive deformation is determined according to ASTM D1056-20.

[0121] The compression set of silicone foam, as determined by ASTM D1056-20 B2, can be 0% to 5%.

[0122] In one aspect, compressible silicone foam is used as a single layer for thermal management. However, multiple single layers can be stacked and used as a single layer. In one aspect, the thermal management sheet essentially consists of or comprises a single layer of cured compressible foam, such as compressible silicone foam, or multiple layers of compressible silicone foam. Other layers can be used in combination with the compressible silicone foam, such as flame-retardant layers, non-porous elastomer barrier layers, adhesive layers, etc., or combinations thereof. However, one advantage of silicone foam is that a single sheet used alone can be effective even at thicknesses as low as 1 mm to 30 mm, or 1 mm to 20 mm, or 1 mm to 15 mm, or 1 mm to 10 mm, or 1 mm to 8 mm, or 1 mm to 6 mm without other layers.

[0123] If used, the flame-retardant layer may comprise flame-retardant inorganic materials (e.g., boehmite, aluminum hydroxide, magnesium hydroxide), intumescent materials, or combinations thereof. The intumescent material may comprise an acid source, a blowing agent, and a carbon source. Each component may exist in a separate layer or as a mixture, such as a tightly packed mixture. For example, the intumescent material may comprise an acid source, a blowing agent, and a carbon source. For example, when the temperature reaches, for example, 200°C to 280°C, the acidic substance (e.g., an acidic form of polyphosphoric acid) may react with the carbon source (e.g., pentaerythritol) to form char. When the temperature rises to, for example, 280°C to 350°C, the blowing agent may then decompose to produce gaseous products that cause the char to expand.

[0124] The acid source may include, for example, organic or inorganic phosphorus compounds, organic or inorganic sulfate esters / salts (e.g., ammonium sulfate), or combinations thereof. Organic or inorganic phosphorus compounds may include organophosphate esters / salts or organophosphonates / salts (e.g., tris(2,3-dibromopropyl) phosphate, tris(2-chloroethyl) phosphate, tris(2,3-dichloropropyl) phosphate, tris(1-chloro-3-bromoisopropyl) phosphate, bis(1-chloro-3-bromoisopropyl)-1-chloro-3-bromoisopropylphosphonate, polyaminotriazine phosphate, melamine phosphate, triphenyl phosphate, or amidourea phosphate); organophosphites (e.g., trimethyl phosphite or triphenyl phosphite); phosphazenes (e.g., hexaphenoxycyclotriphosphazene); phosphorus-containing inorganic compounds (e.g., phosphoric acid, phosphorous acid, phosphites, urea phosphate, ammonium phosphate (e.g., ammonium monohydrogen phosphate, ammonium dihydrogen phosphate, or ammonium polyphosphate)); or combinations thereof.

[0125] The blowing agent can be a physical blowing agent or a chemical blowing agent. In one aspect, the blowing agent may include an agent that decomposes (e.g., decomposes into smaller compounds such as ammonia or carbon dioxide) at a temperature greater than or equal to 120°C, for example, between 120°C and 200°C or between 130°C and 200°C. The blowing agent may include dicyandiamide, azodicarbonamide, melamine, guanidine, glycine, urea (e.g., urea-formaldehyde resin or hydroxymethylated amidourea phosphate), halogenated organic materials (e.g., chlorinated paraffin), or combinations thereof. Alternatively, the blowing agent may include a physical blowing agent. Exemplary physical blowing agents include hydrogen-containing components that may be used alone or as a mixture of each other or with another type of blowing agent. These blowing agents may be selected from a wide range of substances, including hydrocarbons; ethers; esters and partially halogenated hydrocarbons, ethers, and esters, etc. Examples of physical blowing agents have boiling points of -50°C to 100°C or -50°C to 50°C. Among them, the hydrogen-containing blowing agents are HCFCs (halochlorofluorocarbons), such as 1,1-dichloro-1-fluoroethane, 1,1-dichloro-2,2,2-trifluoroethane, monochlorodifluoromethane, and 1-chloro-1,1-difluoroethane; and HFCs (halofluorocarbons), such as 1,1,1,3,3,3-hexafluoropropane, 2,2,4,4-tetrafluorobutane, 1,1,1,3,3,3-hexafluoro-2-methylpropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2,2-pentafluoropropane, 1,1,1,2,3-pentafluoropropane, 1,1,2,3,3-pentafluoropropane, 1,1,2 ... Fluoropropane, 1,1,1,3,3,4-hexafluorobutane, 1,1,1,3,3-pentafluorobutane, 1,1,1,4,4,4-hexafluorobutane, 1,1,1,4,4-pentafluorobutane, 1,1,2,2,3,3-hexafluoropropane, 1,1,1,2,3,3-hexafluoropropane, 1,1-difluoroethane, 1,1,1,2-tetrafluoroethane, (Z)-1,1,1,4,4,4-hexafluoro-2-butene, and pentafluoroethane; HFE (halofluoroethers), such as methyl-1,1,1-trifluoroethyl ether and difluoromethyl-1,1,1-trifluoroethyl ether; and hydrocarbons, such as n-pentane, isopentane, and cyclopentane. In one aspect, the blowing agent may include carbon dioxide, nitrogen, argon, water, air, nitrogen, and inert gases (e.g., helium and argon), and combinations thereof. In one aspect, the blowing agent may include carbon dioxide, such as solid carbon dioxide (i.e., dry ice), liquid carbon dioxide, gaseous carbon dioxide, or supercritical carbon dioxide.

[0126] The expanding material may contain a carbon source. The carbon source may include dextrin, phenolic resin, pentaerythritol (e.g., its dimer or trimer), clay, polymer (e.g., polyamide 6, amino-poly(imidazoline-amide), or polyurethane), or combinations thereof. The amino-poly(imidazoline-amide) may contain repeating amide linkage groups and imidazoline groups.

[0127] The expanding material may optionally include a binder. The binder may include epoxy resin, polyurethane, polysulfide, polysiloxane, polysilalkylene, or combinations thereof. Based on the total weight of the expanding material, the binder may be present in the expanding material in an amount of less than or equal to 50% by weight, or from 5% to 50% by weight, or from 35% to 45% by weight. Based on the total weight of the expanding material, the binder may be present in the expanding material in an amount of 5% to 95% by weight or from 40% to 60% by weight.

[0128] The intumescent material may optionally contain synergistic compounds to further improve its flame retardancy. Synergistic compounds may include boron compounds (e.g., zinc borate, boron phosphate, or boron oxide), silicon compounds, aluminosilicates, metal oxides (e.g., magnesium oxide, iron oxide, or alumina hydrate (boehmite)), metal salts (e.g., alkali metal salts or alkaline earth metal salts of organic sulfonic acids, or alkaline earth metal carbonates), or combinations thereof. Synergistic combinations may include at least one of the foregoing and a phosphorus-containing compound.

[0129] The flame retardant layer may also contain charring agents, such as lignin, boehmite, clay nanocomposites, expandable graphite, pentaerythritol, cellulose, nano-silica, ammonium polyphosphate, lignin sulfonate, melamine, cyanurate, zinc borate, calcium magnesium carbonate, magnesia, or combinations thereof. Unbound by theory, similar to intumescent materials, charring agents are thought to utilize two energy absorption mechanisms (including the formation of char followed by its expansion) to reduce flame spread.

[0130] The flame-retardant layer may also contain a polymer binder, such as silicone, polyurethane, ethylene-vinyl acetate, ethylene-methyl acrylate, ethylene-butyl acrylate, or combinations thereof. The thickness of the flame-retardant layer may be 0.1 mm to 2 mm, 0.5 mm to 1.5 mm, or 0.8 mm to 1.1 mm.

[0131] If used, the non-porous elastomer barrier layer comprises an elastomer having a strength of less than 20 g-mm / m, measured at 25°C and 1 atmosphere, respectively. 2 / day, or less than 10 g-mm / m 2 / day, or less than 5 g-mm / m 2 / day water permeability coefficient; or tensile stress at 100% elongation, measured at 21°C according to ASTM 412, from 0.5 MPa to 15 MPa; or a combination thereof. The thickness of the non-porous elastomer barrier layer can be from 0.25 mm to 1 mm or from 0.4 mm to 0.8 mm.

[0132] Non-porous elastomeric barrier layers can contain hydrophobic elastomeric materials to prevent the permeation of water or water vapor. For example, the elastomeric barrier layer can contain thermoplastic elastomers (TPEs), provided that they have the desired hydrophobicity (insufficient water or water vapor permeability). Categories of TPEs include styrene block copolymers (TPS or TPE-s), (TPO or TPE-o), thermoplastic vulcanizates (TPV or TPE-v), thermoplastic polyurethanes, thermoplastic copolyesters (TPC or TPE-E), thermoplastic polyamides (TPA or TPE-A), and so on.

[0133] Examples of usable elastomer materials include acrylic rubbers, butyl rubbers, halogenated butyl rubbers, copolyesters, epichlorohydrin rubbers, ethylene-acrylic rubbers, ethylene-butylacrylic rubbers, ethylene-diene rubbers (EPRs) such as ethylene-propylene rubber, ethylene-propylene-diene monomer rubbers (EPDM), ethylene-vinyl acetate, fluorinated elastomers, perfluorinated elastomers, polyamides, polybutadiene, polychloroprene, polyolefin rubbers, polyisoprene, polysulfide rubbers, natural rubber, nitrile rubber, low-density polyethylene, polypropylene, thermoplastic polyurethane elastomers (TPU), silicone rubbers, fluorinated silicone rubbers, styrene-butadiene, styrene-isoprene, vinyl rubbers, or combinations thereof. In one aspect, the non-porous elastomer barrier layer comprises ethylene-propylene-diene monomer rubber, polychloroprene, or combinations thereof.

[0134] Adhesive layers may be present to adhere one thermal management sheet containing silicone foam to another thermal management sheet, another type of layer, or to a single cell array or cell assembly. A wide variety of suitable adhesives can be used for the thermal management sheets. Adhesives can be selected for ease of application and stability under the operating conditions of the cell. Each adhesive layer may be the same or different and may have the same or different thicknesses. Suitable adhesives include phenolic resins, epoxy adhesives, polyester adhesives, polyvinyl fluoride adhesives, acrylic or methacrylic adhesives, or silicone adhesives, preferably acrylic or silicone adhesives. In one aspect, the adhesive is a silicone adhesive. Solvent-cast adhesives, hot-melt adhesives, and two-part adhesives can be used. Each adhesive layer may independently have a thickness of 0.00025 inches to 0.010 inches (0.006 mm to 0.25 mm), or 0.0005 inches to 0.003 inches (0.01 mm to 0.08 mm).

[0135] When the thermal management sheet includes an adhesive layer, the thermal management sheet may also include a release layer. "Release layer" means any layer including a release coating that is optionally supported by one or more additional layers including a release liner. The thickness of each release layer can be from 5 micrometers (μm) to 150 micrometers, 10 μm to 125 μm, 20 μm to 100 μm, 40 μm to 85 μm, or 50 μm to 75 μm.

[0136] The compressible silicone foam of this disclosure can be particularly used in assemblies for batteries or battery components (e.g., the walls of a battery casing). Therefore, another aspect of this disclosure is an assembly for a battery that includes a thermal management sheet comprising a compressible silicone foam disposed on the surface of an electrochemical single cell. The single cell can be a lithium-ion single cell, particularly a prismatic single cell, a cylindrical single cell, or a pouch-shaped single cell. Figure 2 One aspect of the positioning of compressible silicone foam in a single-cell battery assembly 1002 is shown, and Figure 3 This illustrates another aspect of the positioning of compressible silicone foam in the single-cell battery assembly 1003. Figure 2 and Figure 3 The thermal management sheet 10 is shown to be located between the first single cell 103 and the second single cell 104. Figure 2 The thermal management sheet 10 is shown to be approximately the same size as the individual cells 103 and 104 in height and width. Figure 3 This illustrates that the thermal management sheet 10 can be smaller than the corresponding single cell 103, 104. Similarly, as... Figure 3 As shown, the thermal management sheet 10 may also extend beyond the edges of the electrochemical cells 103, 104. The thermal management sheet containing compressible silicone foam extending beyond the edges of the electrochemical cells may wrap around and cover at least another portion or all of another surface of the cell.

[0137] Figure 4 The multi-cell battery arrangement 1004 shown may include more than two individual cells 103, 104, wherein a thermal management sheet 10 is located between the respective individual cells 103, 104. The individual cells may be lithium-ion cells, particularly pouch cells. Figure 4An assembly 1004 for a battery is shown, which may include more than two individual cells (e.g., 103, 104), wherein a thermal management sheet 10 is located between each of the respective individual cells 103, 104 and the other individual cells. In one aspect, during the manufacture of the assembly 1004 for the battery, two to ten compressible silicone foam sheets may be disposed on the individual cells or in an array of individual cells. For example, two to ten compressible silicone foam sheets may be disposed on the inside of the battery (e.g., facing the electrodes) or on the outside. Two to ten fire-retardant compressible silicone foam sheets may be disposed on or adhered to the individual cells or bags of a pouch-shaped battery, or both. Of course, depending on the number of individual cells and the array of individual cells, one or more than ten compressible silicone foam sheets may be present. Figure 4 Also shown is a thermal management sheet 10a disposed on the outside of the assembly 1004 for the battery, facing the outside of the battery.

[0138] In one aspect, at least a portion of the exposed outer edge of the thermal management sheet comprising compressible silicone foam may include a material 88 that carries heat away from the body of the thermal management sheet, such as... Figure 4 As shown in the figure. Exemplary materials applied to the exposed edges of compressible silicone foam include ceramics such as boron nitride or aluminum nitride, metals such as aluminum, high heat capacity waxes, phase change materials, etc., or combinations thereof.

[0139] A single-cell assembly is used in a battery. The battery includes a housing that at least partially surrounds one or more electrochemical single cells or an array of single cells. The housing can be of any type, such as a polymer or pouch cell. Thermal management sheets can be disposed on or directly disposed on any configured single cell or array of single cells in the battery. The thermal management sheets can be placed between the individual single cells or arrays of single cells in the battery. Compressible silicone foam can be placed on the sides, a portion of the sides, or selected groups of single cells or arrays of single cells in the battery, such as on top, between, below, adjacent, or combinations thereof. Compressible silicone foam can be placed on or adhered to a plurality of pouch cells, pressure management pads, cooling plates, or other internal battery components. Assembly pressure of the battery holds the stacked components in place.

[0140] For example, such as Figure 5 As shown, battery 2001 may include a plurality of individual cells in a plurality of individual cell arrays 960 inside housing 980. Thermal management sheet 10 may be disposed between two individual cell arrays 960. Further as... Figure 5As shown, the thermal management sheet 10 can be disposed between the side of the housing 980 and the side of the individual cell array 960 along the plurality of individual cells of the cell array. Similarly, as... Figure 5 As shown, the thermal insulation sheet 10 can be disposed between the end of the housing 980 and the end of one or more individual cell arrays 960.

[0141] If more than one compressible silicone foam sheet or other layer is used, the sheets and layers can be assembled using methods known in the art. The sheets and layers can be assembled onto the surface of a single cell or other component of the battery (e.g., the wall of a battery casing). In one aspect, the sheets and layers are assembled separately and then placed or adhered to a single cell, battery assembly, or both. Each of the sheets or layers can be manufactured separately and then stacked in a desired order (placed or adhered using, for example, one or more adhesive layers). Alternatively, one or more individual layers can be manufactured onto another individual layer, for example, by coating, molding, or lamination using heat and pressure. For example, in one aspect, a flame-retardant layer or adhesive layer can be directly molded onto the compressible silicone foam. Direct coating or molding can reduce thickness and improve flame retardancy by omitting the adhesive layer.

[0142] The following examples are provided to illustrate the present disclosure. These examples are merely illustrative and are not intended to limit any apparatus made according to the present disclosure to the materials, conditions, or process parameters set forth therein.

[0143] Example

[0144] Table 1 describes the materials used in the following embodiments.

[0145] Table 1

[0146]

[0147] The foam of this embodiment is prepared using the following general mixing method.

[0148] A first foam precursor mixture (“Part A”) was prepared by adding polyorganosiloxanes A to F, a foaming agent (i.e., DI water, BuOH, BzOH), a Pt catalyst, and an initiator to a mixing cup. The mixture was mixed in a FlackTek speed mixer at 2000 rpm for 30 seconds. The fillers (ATH, ZB) were added sequentially to the mixture. The mixture was then mixed in the speed mixer according to the following schedule: 2100 rpm for 8 seconds, 2300 rpm for 8 seconds, 2500 rpm for 10 seconds, 2650 rpm for 8 seconds, and 2750 rpm for 8 seconds. After mixing, the cup was removed and cooled to 40°F (4.4°C).

[0149] A second foam precursor mixture (“Part B”) comprising polyorganosiloxanes G to J is provided. The first foam precursor mixture and the second foam precursor mixture are combined in a specific weight ratio to obtain foam. For example, the first foam precursor mixture and the second foam precursor mixture are combined in a desired weight ratio. After manually mixing the two components thoroughly for 35 seconds, the mixture was dispensed as quickly as possible onto a thin polyethylene terephthalate (PET) sheet (4 mils (0.1016 mm)) and stretched between rollers with a roll gap of 25 mils (0.025 inches (0.635 mm)). The resulting foam sandwiched between two PET films was placed in a convection oven set to 90°C for 3 minutes, followed by an additional 2 minutes for further curing. After a total of 5 minutes, the cast foam was peeled off from the backing PET film. The foam thickness was then measured, and the expansion was calculated using the following formula: Expansion = (Final foam thickness) / ((Roll gap) - (PET film thickness)). After 24 hours, the layered foam sheet was placed in a convection oven set to 100°C for 24 hours for post-curing. The density, compression set (25%, 50%, and 80%), and compression set permanent (22 hours, 100°C) of the post-cured foam were then characterized (ASTM). (D1056-20 B2). Flammability was characterized according to UL-94. Samples achieving a V0 rating were characterized as "passed" in Table 2.

[0150] Table 2 provides the amounts of components used to prepare the foams of each embodiment, as a weight percentage based on either the total weight of the first foam precursor mixture (“Part A”) or the total weight of the second foam precursor mixture (“Part B”), and in grams (g). Table 2 also shows a characteristic description of each foam embodiment.

[0151] Table 2

[0152]

[0153] 1 CFD at 70%

[0154] Comparative Examples 1 to 3 contain only polyorganosiloxane A (in part A) and polyorganosiloxane G (in part B), and do not contain polyorganosiloxanes B to F (in part A) or H to J (in part B). The molar ratio of hydrogen groups to the sum of vinyl and hydroxyl groups in Comparative Examples 4 and 5 is 1.17 to 1.19, and the molar ratio of hydrogen groups to the sum of vinyl and hydroxyl groups in Examples 1 to 5 is 1.2 to 1.31.

[0155] The composition according to Comparative Example 3 could not provide cast foam. The compositions according to Comparative Examples 4 and 5 produced a sticky foam material that could not be removed from the backing layer. Therefore, the compositions according to Comparative Examples 4 and 5 were not characterized. The compositions according to Comparative Examples 1 and 2 provided foam, but exhibited high CFD values ​​even at 25%. As will be further discussed below, the foam according to this disclosure exhibits the desired thermal properties. Therefore, the foam according to this disclosure can provide a very soft and compressible material while maintaining the desired thermal properties.

[0156] In contrast, the compositions according to Examples 1 to 5 produce highly compressible and flame-retardant cast foam. Figure 6 These are graphs showing the compressive force deformation of Comparative Examples 1 and 2, as well as Examples 1 to 5. (See figure) Figure 6 As shown, the foams of Comparative Examples 1 and 2 exhibited high compressive stresses as strain increased. In contrast, the foams of Examples 1 to 5 maintained low compressive stresses (e.g., less than 1,000 kPa) even at strains greater than 70%. Furthermore, as... Figure 6 As shown, the foams according to Examples 1 and 2 begin to exhibit a large increase in observed compressive stress between 60% and 70% strain. In contrast, the foams according to each of Examples 1 to 5 in accordance with this disclosure do not exhibit the same significant increase in compressive stress within the tested strain (i.e., up to 80%). The combination of low compressive stress and the delayed onset of the observed increase in compressive stress represents a significant advantage of highly filled foams.

[0157] Nail penetration test

[0158] Perform a nail penetration test. Figure 7A and Figure 7B These are exploded and non-exploded views of a first device 7000 used for nail penetration testing. The first device 7000 includes aluminum end plates 910 and 920 (185 mm × 90 mm × 15.2 mm), insulating films 930 and 940 (185 mm × 90 mm × 1 mm), pouch-shaped individual cells 201 and 202, and a sample 950 to be tested. The characteristics of individual cells 201 and 202 are provided in Table 3. Individual cell 201 was punctured by an 8 mm nail inserted at an indentation rate of 10 mm / s to induce runaway. Individual cells 201 and 202 were electrically isolated. Temperature profiles were measured using multiple thermocouples (T1 to T9). Voltage was also measured.

[0159] Table 3

[0160]

[0161] The results of the nail penetration test for Comparative Example 2 and Example 2 (at two thicknesses) are shown in Table 4 and Figures 8 to 9.

[0162] Table 4

[0163]

[0164] Figures 8a and 8b are graphs of temperature (°C) or voltage (volts (V)) versus time (seconds (s), respectively, showing the results of a nail penetration test of Example 2 at a thickness of 1.36 mm. The results show a 90-second delay for Example 2 at a thickness of 1.36 mm. Figures 9a and 9b are graphs of temperature (°C) or voltage (volts (V)) versus time (s), respectively, showing the results of a nail penetration test of Example 2 at a thickness of 3.47 mm. Notably, for Example 2, a delay greater than 50,000 seconds was observed, and for Comparative Example 2 at a similar thickness (e.g., 3.1 mm to 3.5 mm), a delay greater than 7,000 seconds was observed, as shown in International Publication No. WO 2022 / 192213, the contents of which are incorporated herein by reference in their entirety. Therefore, the foam according to this disclosure can provide a very soft and compressible material while maintaining desired thermal properties, providing delay or prevention of thermal runaway. Advantageously, even significantly thinner foams can provide a delay in thermal runaway compared to prior materials. The increased compressibility of the foam of the present invention can advantageously provide reduced stress on the battery cells, enabling longer lifespan and enhanced safety (e.g., reduced leakage due to pressure exerted by the foam). Therefore, the specific materials described herein can provide a unique combination of properties not available with prior materials.

[0165] Thermal test

[0166] The thermal properties of various samples were determined in thermal runaway simulation. Figure 10 An apparatus 5000 for thermal testing is shown. A thermal management sheet 10 is placed directly on a hot plate 960 set to 550°C. Foam is placed on the hot plate. A 12.7 mm stainless steel single-cell analogue 970 is placed on the top surface of the thermal management sheet 10. A thermocouple sensor 980 is inserted into a hole drilled in the mica analogue 970 to position the thermocouple sensor 980 on the top surface of the thermal management sheet 10.

[0167] Figure 11The temperature rise of each sample over time, measured by thermocouples, is shown. Advantageously, Examples 1 to 3 and Comparative Example 1 demonstrate the desired thermal barrier properties. Therefore, the foam according to this disclosure can provide a very soft and compressible material while still maintaining the desired thermal properties. Thus, the specific materials described herein can provide a unique combination of properties not available with prior materials.

[0168] Therefore, this disclosure provides significant improvements.

[0169] This disclosure also covers the following aspects.

[0170] Aspect 1: A curable composition for preparing compressible silicone foam, comprising: an alkenyl-containing component, based on the total weight of the curable composition, the alkenyl-containing component comprising 30 to 75 wt% of an alkenyl-double-terminated polysiloxane, 0.5 to 5 wt% of an alkenyl-substituted MQ polysiloxane, and 0.1 to 5 wt% of an alkenyl-substituted copolysiloxane; and a hydrogen-containing component comprising a hydrogen-substituted polysiloxane; a curing catalyst; a filler composition; and a blowing agent.

[0171] Aspect 2: The curable composition according to aspect 1, wherein the filler composition comprises: a first filler that decomposes upon initial exposure to heat to produce water; and a second filler different from the first filler, wherein the second filler forms a thermal barrier layer with the decomposition products of the first filler, or absorbs water, or both.

[0172] Aspect 3: The curable composition according to aspect 2, wherein the first filler and the second filler are at least two of aluminum trihydrate, ammonium nitrate, sodium borate, hydrated sodium silicate, magnesium hydroxide, basic magnesium carbonate pentahydrate, magnesium triphosphate octahydrate, zinc borate, superabsorbent polymer or water glass.

[0173] Aspect 4: The curable composition according to aspect 3, wherein the first filler comprises aluminum trihydrate, sodium silicate hydrate, basic magnesium carbonate pentahydrate, magnesium triphosphate octahydrate, superabsorbent polymer, water glass, or a combination thereof.

[0174] Aspect 5: The curable composition according to aspect 3 or 4, wherein the second filler comprises ammonium nitrate, sodium borate, hydrated sodium silicate, magnesium hydroxide, basic magnesium carbonate pentahydrate, magnesium triphosphate octahydrate, zinc borate, superabsorbent polymer, or a combination thereof.

[0175] Aspect 6: A curable composition according to any one of Aspects 1 to 5, wherein the filler composition comprises aluminum trihydrate and zinc borate.

[0176] Aspect 7: A curable composition according to any one of Aspects 1 to 6, wherein the alkenyl-dual-terminated polyorganosiloxane comprises a vinyl-dual-terminated polydimethylsiloxane, preferably the vinyl-dual-terminated polydimethylsiloxane has a viscosity greater than 10,000 centipoise, preferably a viscosity of 50,000 to 150,000 centipoise.

[0177] Aspect 8: A curable composition according to any one of Aspects 1 to 6, wherein the alkenyl-double-terminated polyorganosiloxane comprises a first alkenyl-double-terminated polyorganosiloxane with a viscosity greater than 10,000 centipoise, preferably with a viscosity of 50,000 to 150,000 centipoise, preferably comprising a first vinyl-double-terminated polydimethylsiloxane; and a second alkenyl-double-terminated polyorganosiloxane with a viscosity less than or equal to 10,000 centipoise, preferably with a viscosity of 100 to 500 centipoise, preferably comprising a second vinyl-double-terminated polydimethylsiloxane.

[0178] Aspect 9: A curable composition according to any one of Aspects 1 to 8, wherein the alkenyl-substituted copolysiloxane comprises a vinyl-double-terminated polydimethylsiloxane containing vinyl side groups, preferably the vinyl-double-terminated polydimethylsiloxane containing vinyl side groups has a viscosity of less than 1,000 centipoise, more preferably 100 to 500 centipoise.

[0179] Aspect 10: A curable composition according to any one of Aspects 1 to 9, wherein the curing catalyst comprises platinum.

[0180] Aspect 11: The curable composition according to any one of Aspects 1 to 10, comprising, based on the total weight of the curable composition, 10 to 70% by weight, or 20 to 60% by weight, or 20 to 50% by weight of the filler composition.

[0181] Aspect 12: A curable composition according to any one of Aspects 1 to 11, wherein the foaming agent comprises: water; a silanol-terminated polyorganosiloxane; and C 1-12 Monohydric alcohol.

[0182] Aspect 13: A curable composition according to any one of Aspects 1 to 12, wherein, based on the total weight of the curable composition, the curable composition comprises 0.5 to 2 weight percent of the blowing agent; preferably, wherein the blowing agent comprises: 0.01 to 0.5 weight percent of water, 0.1 to 1 weight percent of a silanol-terminated polyorganosiloxane, and 0.05 to 0.5 weight percent of C 1-12 Monohydric alcohols; each based on the total weight of the curable composition.

[0183] Aspect 14: The curable composition according to any one of aspects 12 to 13, wherein the C 1-12 The monohydric alcohol is butanol.

[0184] Aspect 15: The curable composition according to any one of Aspects 1 to 14 further comprises an inhibitor of an alkenyl-dextended polyorganosiloxane, said inhibitor having a vinyl content of greater than or equal to 15% by weight based on the total weight of said alkenyl-dextended polyorganosiloxane, a molecular weight of less than 500 g / mol, or both.

[0185] Aspect 16: The curable composition according to aspect 15 comprises 0.01 to 0.4 weight percent of the inhibitor, wherein the weight percent is based on the total weight of the alkenyl-containing component and the hydrogen-containing component.

[0186] Aspect 17: A curable composition according to any one of Aspects 1 to 16, wherein the alkenyl-containing component of the curable composition further comprises a monoalkenyl-terminated polyorganosiloxane.

[0187] Aspect 18: The curable composition according to aspect 17, wherein the monoalkenyl-terminated polyorganosiloxane is present in an amount of 0.5 to 5% by weight based on the total weight of the curable composition.

[0188] Aspect 19: A curable composition according to any one of Aspects 1 to 18, wherein the alkenyl-containing component and the hydrogen-containing component are present in a weight ratio of alkenyl-containing component to hydrogen-containing component of 10:1 to 40:1, or 13:1 to 40:1, or 13:1 to 25:1, or 13:1 to 20:1.

[0189] Aspect 20: A curable composition according to any one of aspects 1 to 19, wherein the curable composition comprises a molar ratio of hydrogen groups to the sum of alkenyl and hydroxyl groups of 1.1:1 to 2.5:1, or 1.1:1 to 2:1, or 1.1:1 to 1.5:1.

[0190] Aspect 21: The curable composition according to any one of Aspects 1 to 20, wherein the thickness of the compressible silicone foam is 1 mm to 30 mm, or 1 mm to 20 mm, or 1 mm to 15 mm, or 1 mm to 1 mm, or 1 mm to 8 mm, or 1.2 mm to 8 mm, or 1.5 mm to 8 mm, or 1.5 mm to 6 mm, or 2.5 mm to 6 mm.

[0191] Aspect 22: A compressible silicone foam comprising a cured product of a curable composition according to any one of aspects 1 to 21.

[0192] Aspect 23: The compressible silicone foam according to aspect 22, wherein the density of the compressible silicone foam is less than 400 kg / m³.

[0193] Aspect 24: The compressible silicone foam according to aspect 22 or 23, wherein the compressible silicone foam has a compressive force deformation of less than 25% of deformation at less than 35 kPa, a compressive force deformation of less than 50% of deformation at less than 100 kPa, and a compressive force deformation of less than 80% of deformation at less than 1000 kPa; wherein the compressive force deformation is determined according to ASTM D1056-20.

[0194] Aspect 25: An assembly for a battery comprising a compressible silicone foam according to any one of Aspects 22 to 24 disposed on the surface of an electrochemical single cell, preferably a lithium-ion electrochemical single cell.

[0195] Aspect 26: The assembly according to aspect 25, wherein the electrochemical single cell includes a prismatic single cell, a pouch single cell, or a cylindrical single cell.

[0196] Aspect 27: The assembly according to aspect 25 or 26, wherein the assembly comprises at least two electrochemical single-cell batteries.

[0197] Aspect 28: A battery comprising: an assembly for the battery according to any one of aspects 25 to 27; and a housing that at least partially surrounds the assembly for the battery.

[0198] Aspect 29: A method for forming a compressible silicone foam sheet, the method comprising: casting a curable composition according to any one of Aspects 1 to 21 onto a first release layer; placing a second release layer on the side of the cast curable composition opposite to the first release layer to form a multilayer structure; passing the cast curable composition on a substrate through the gap between two rotating rollers to control the amount of the curable composition; and curing the curable composition to form the compressible silicone foam sheet.

[0199] Aspect 30: The method according to aspect 29 further includes mixing the alkenyl-containing component and the hydrogen-containing component to provide the curable composition.

[0200] Aspect 31: A compressible silicone foam formed according to the method described in aspect 29 or 30.

[0201] Compositions, methods, and articles may alternatively include, consist of, or be substantially composed of any suitable materials, steps, or components disclosed herein. Compositions, methods, and articles may also be formulated to be free of or substantially free of any materials (or substances), steps, or components that are otherwise not essential for achieving the function or purpose of the composition, method, and article.

[0202] All scopes disclosed herein include endpoints, and endpoints may be combined independently of each other. "Combination" includes blends, mixtures, alloys, reaction products, etc. The terms "first," "second," etc., do not indicate any order, quantity, or importance, but are used to distinguish one element from another. The terms "an," "a," and "the" do not indicate a limitation of quantity and, unless otherwise indicated herein or obviously contradicted by the context, should be construed as encompassing both the singular and plural forms. Unless otherwise expressly stated, "or" means "and / or." References to "an aspect" throughout the specification mean that a particular element described in connection with that aspect is included in at least one aspect described herein and may or may not be present in other aspects. The term "combination thereof," as used herein, includes one or more of the listed elements and is open to the presence of one or more unnamed similar elements. Furthermore, it should be understood that the described elements may be combined in any suitable manner in each aspect.

[0203] Unless otherwise stated herein, all test standards are the most recent standards in effect as of the filing date of this application (or, if priority is claimed, the filing date of the earliest priority application in which such test standard appears).

[0204] Unless otherwise specified, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in this application contradicts or conflicts with a term in an incorporated reference, the term from this application shall take precedence over the conflicting term from the incorporated reference.

[0205] Compounds are described using standard nomenclature. For example, any position not substituted by any specified group is understood to be filled with the indicated bond or hydrogen atom at its valence. A hyphen ("-") not between two letters or symbols is used to indicate the connection point of a substituent. For example, -CHO is connected to the carbonyl group.

[0206] Exemplary embodiments are described herein with reference to cross-sectional views as schematic diagrams of idealized embodiments. Therefore, variations in the illustrated shapes due to, for example, manufacturing techniques and / or tolerances should be expected. Consequently, the embodiments described herein should not be construed as limited to the specific region shapes shown herein, but rather include, for example, shape deviations caused by manufacturing processes. For example, regions shown or described as flat may generally have rough and / or non-linear characteristics. Furthermore, the sharp corners shown may be rounded. Therefore, the regions shown in the figures are substantially schematic, and their shapes are not intended to represent the precise shapes of the regions, nor are they intended to limit the scope of these claims.

[0207] While specific embodiments have been described, alternatives, modifications, variations, improvements, and substantially equivalents may be conceived by the applicant or others skilled in the art that are not currently foreseen or may not be foreseen. Therefore, the appended claims, both submitted and potentially amended, are intended to cover all such alternatives, modifications, variations, improvements, and substantially equivalents.

Claims

1. A curable composition for preparing compressible silicone foam, comprising: The alkenyl-containing component, based on the total weight of the curable composition, comprises: 30 to 75 percent by weight of alkenyl-dual-terminated polyorganosiloxanes; 0.5% to 5% by weight of alkenyl-substituted MQ polyorganosiloxane; 0.1 to 5 wt% of alkenyl-substituted copolysiloxanes; and A hydrogen-containing component, wherein the hydrogen-containing component comprises a hydrogen-substituted polyorganosiloxane; Solidified catalyst; Filler composition; and Foaming agent.

2. The curable composition according to claim 1, wherein the filler composition comprises: The first filler material decomposes to produce water upon initial exposure to heat; and The second packing material is different from the first packing material. The second filler forms a thermal barrier layer with the decomposition products of the first filler, or the second filler absorbs the water, or both.

3. The curable composition according to claim 2, wherein the first filler and the second filler are at least two of aluminum trihydrate, ammonium nitrate, sodium borate, hydrated sodium silicate, magnesium hydroxide, basic magnesium carbonate pentahydrate, magnesium triphosphate octahydrate, zinc borate, superabsorbent polymer or water glass.

4. The curable composition according to claim 3, The first filler comprises aluminum trihydrate, sodium silicate hydrate, basic magnesium carbonate pentahydrate, magnesium triphosphate octahydrate, superabsorbent polymer, water glass, or a combination thereof; and The second filler includes ammonium nitrate, sodium borate, hydrated sodium silicate, magnesium hydroxide, basic magnesium carbonate pentahydrate, magnesium triphosphate octahydrate, zinc borate, superabsorbent polymer, or a combination thereof.

5. The curable composition according to any one of claims 1 to 4, wherein the filler composition comprises aluminum trihydrate and zinc borate.

6. The curable composition according to any one of claims 1 to 5, wherein the alkenyl-dextended polyorganosiloxane comprises vinyl-dextended polydimethylsiloxane, preferably the vinyl-dextended polydimethylsiloxane has a viscosity greater than 10,000 centipoise, preferably a viscosity of 50,000 to 150,000 centipoise.

7. The curable composition according to any one of claims 1 to 5, wherein the alkenyl-double-terminated polyorganosiloxane comprises: A polyorganosiloxane with a viscosity greater than 10,000 centipoise, preferably with a viscosity of 50,000 to 150,000 centipoise, and preferably including a polydimethylsiloxane with a first vinyl double end; and Polyorganosiloxanes with a viscosity of less than or equal to 10,000 centipoise, preferably with a viscosity of 100 to 500 centipoise, and more preferably polydimethylsiloxanes including a second vinyl double-terminated end.

8. The curable composition according to any one of claims 1 to 7, wherein the alkenyl-substituted copolysiloxane comprises a vinyl-double-terminated polydimethylsiloxane containing vinyl side groups, preferably the vinyl-double-terminated polydimethylsiloxane containing vinyl side groups has a viscosity of less than 1,000 centipoise, more preferably 100 to 500 centipoise.

9. The curable composition according to any one of claims 1 to 8, wherein the curing catalyst comprises platinum.

10. The curable composition according to any one of claims 1 to 9, comprising, based on the total weight of the curable composition, 10 to 70% by weight, or 20 to 60% by weight, or 20 to 50% by weight of the filler composition.

11. The curable composition according to any one of claims 1 to 10, wherein the foaming agent comprises: water; Silanol-terminated polyorganosiloxanes; and C 1-12 Monohydric alcohol.

12. The curable composition according to any one of claims 1 to 11, wherein the curable composition comprises 0.5 to 2% by weight of the foaming agent based on the total weight of the curable composition; preferably wherein the foaming agent comprises: 0.01% to 0.5% by weight of water, 0.1% to 1% by weight of silanol-terminated polyorganosiloxanes; and 0.05% to 0.5% C by weight 1-12 Monohydric alcohol, preferably butanol; Each is based on the total weight of the curable composition.

13. The curable composition according to any one of claims 1 to 12, further comprising 0.01 to 0.4 weight percent of an inhibitor comprising an alkenyl-double-terminated polyorganosiloxane, said inhibitor having a vinyl content of greater than or equal to 15 weight percent based on the total weight of said alkenyl-double-terminated polyorganosiloxane, a molecular weight of less than 500 g / mol, or both, wherein the weight percent is based on the total weight of said alkenyl-containing component and said hydrogen-containing component.

14. The curable composition according to any one of claims 1 to 13, wherein, based on the total weight of the curable composition, the alkenyl-containing component of the curable composition further comprises 0.5 to 5 weight percent of a monoalkenyl-terminated polyorganosiloxane.

15. The curable composition according to any one of claims 1 to 14, wherein the alkenyl-containing component and the hydrogen-containing component are present in a weight ratio of alkenyl-containing component to hydrogen-containing component of 10:1 to 40:1, or 13:1 to 40:1, or 13:1 to 25:1, or 13:1 to 20:

1.

16. The curable composition according to any one of claims 1 to 15, wherein the curable composition comprises a molar ratio of hydrogen groups to the sum of alkenyl and hydroxyl groups of 1.1:1 to 2.5:1, or 1.1:1 to 2:1, or 1.1:1 to 1.5:

1.

17. The curable composition according to any one of claims 1 to 16, wherein the thickness of the compressible silicone foam is 1 mm to 30 mm, or 1 mm to 20 mm, or 1 mm to 15 mm, or 1 mm to 1 mm, or 1 mm to 8 mm, or 1.2 mm to 8 mm, or 1.5 mm to 8 mm, or 1.5 mm to 6 mm, or 2.5 mm to 6 mm.

18. A compressible silicone foam comprising a cured product of the curable composition according to any one of claims 1 to 17, wherein... The density of the compressible silicone foam is less than 400 kg / m³; The compressible silicone foam has a compressive force deformation of less than 35 kPa at 25% deformation. The compressible silicone foam has a compressive force deformation of less than 100 kPa at 50% deformation, and The compressible silicone foam has a compressive force deformation of less than 1000 kPa at 80% of its deformation. The compressive deformation is determined according to ASTM D1056-20.

19. An assembly for a battery, comprising a compressible silicone foam according to claim 18 disposed on the surface of an electrochemical single cell, preferably a lithium-ion electrochemical single cell.

20. A battery, comprising: The assembly for a battery according to claim 19; and The housing at least partially surrounds the assembly for the battery.

21. A method for forming a compressible silicone foam sheet, the method comprising: The curable composition according to any one of claims 1 to 17 is cast onto the first release layer; The second release layer is placed on the side of the cast curable composition opposite to the first release layer to form a multilayer structure; The amount of the curable composition is controlled by passing the cast curable composition on the substrate through the gap between two rotating rollers. as well as The curable composition is cured to form the compressible silicone foam sheet.

22. The method of claim 21, further comprising mixing the alkenyl-containing component and the hydrogen-containing component to provide the curable composition.

23. A compressible silicone foam formed by the method according to claim 21 or 22.

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