Structured cushioning articles

Abstract

A cushioning article includes a plurality of structures disposed on a base layer of the cushioning article. The structures are arranged along a width of the cushioning article and extends along a length of the cushioning article. Each structure includes opposing first and second sidewalls extending along a thickness direction of the cushioning article from the base layer to a curved top portion of the structure, such that in a first cross-section orthogonal to the length of the cushioning article and for each structure of the plurality of structures, the curved top portion is concave toward the base layer and at least portions of each of the first and second sidewalls are tilted toward a same first direction along the width of the cushioning article. The structures can be formed from a cross-linked silicone elastomer with filler dispersed therein.

Description

[0001] PA103289W002

[0002] STRUCTURED CUSHIONING ARTICUES

[0003] TECHNICAL FIELD

[0004] The present description relates generally to the field of cushioning articles.

[0005] BACKGROUND

[0006] Cushioning articles have been made from polymeric foams.

[0007] SUMMARY

[0008] In some aspects, the present description provides a cushioning article including a plurality of structures disposed on a base layer of the cushioning article. The structures are arranged along a width of the cushioning article and extends along a length of the cushioning article. Each structure includes opposing first and second sidewalls extending along a thickness direction of the cushioning article from the base layer to a curved top portion of the structure, such that in a first cross-section orthogonal to the length of the cushioning article and for each structure of the plurality of structures, the curved top portion is concave toward the base layer and at least portions of each of the first and second sidewalls are tilted toward a same first direction along the width of the cushioning article. In some embodiments, the structures are formed from a cross-linked silicone elastomer with filler dispersed therein. In some embodiments, the structures comprise a solid material at no less than 60 volume percent based on a total volume of the structures, where the solid material includes a cross-linked silicone elastomer and solid filler dispersed therein. In some embodiments, the structures comprise a cross-linked silicone elastomer and filler dispersed therein, where the filler includes solid filler material and hollow particles.

[0009] In some aspects, the present description provides a cushioning article including a (e.g., predominately solid) filled crosslinked silicone elastomer having a first major surface including a plurality of structures where an average height of the structures is at least 20% of a total thickness of the cushioning article. The plurality of structures can include asymmetric fin-shaped structures. The cushioning article can further include a second major surface opposite the first major surface which is nominally flat and non-structured, where any surface roughness of the second major surface is less than 3% of the total thickness of the cushioning article.

[0010] In some aspects, the present description provides a cushioning article including a (e.g., predominately solid) filled crosslinked silicone elastomer having a first major surface including a plurality of first structures where an average height of the first structures is at least 10% of a total thickness of the cushioning article. The plurality of first structures can include asymmetric fin-shaped structures. The cushioning article can further include a second major surface having a plurality of second structures where an average height of the second structures is at least 10% of a total thickness of the cushioning article. The plurality of second structures can include fin-shaped structures. In some aspects, the present description relates to the use of a cushioning article or cushioning articles as described herein, for industrial applications, such as for thermal management applications in the transportation industry. One such application is the use of the cushioning articles as cushioning and thermal barriers in between the cells of battery electric vehicles battery assemblies.

[0011] In some embodiments, the structures of the cushioning article comprise a solid material at no less than 40, 50, 60, 70, 80, 90, 95, 96, 97, 98, or 99 volume percent based on a total volume of the structures. In some embodiments, the structures comprise a cross-linked silicone elastomer and filler dispersed therein. In some embodiments, the filler is solid material (e.g., solid particles). In some embodiments, the filler comprises solid filler material and hollow particles. In some embodiments, the structures of the cushioning article are predominately solid.

[0012] Throughout the present description, the term “predominately solid” material refers to a material that comprises solid material (as opposed to gas or liquid) at greater than 50 volume percent. In some embodiments, a predominately solid material has no intentionally created voids, but which may nonetheless comprise in some instances air entrained during the material processing. In some embodiments, the void content in a predominately solid material is 20 or less volume percent. In other embodiments, the void content in a predominately solid material is no more than 17.5, 15, 12.5, 10, 7.5, 5, or 2.5 volume percent. In some embodiments, a predominately solid material may contain additional intentionally created voids, such as, for example, those originating from glass bubbles, polymeric bubbles, or other void-generating agents or materials, as will be described later in this description. In some embodiments, the predominately solid material does not comprise void content derived from blowing agents or traditional methods of making foams. In some embodiments, the predominately solid material is substantially incompressible. For example, any void content of a predominately solid material can have a small (e.g., less 20, 15, or 10 percent) effect on bulk compressibility of the material. Here, bulk compressibility of the material is an intrinsic property of the material (as opposed to being determined by surface structure, for example).

[0013] A fin-shaped structure generally refers to a structure having opposing first and second sidewalls that extend from a base of the structure to a curved top portion of the structure, such that the curved top portion is concave toward the base and at least portions of each of the first and second side walls are tilted toward a same direction.

[0014] These and other aspects will be apparent from the following detailed description. In no event, however, should this brief summary be construed to limit the claimable subject matter.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIGS. 1A-C schematically illustrate battery module assemblies having various cushioning and / or thermal insulation layers between battery cells, according to some embodiments.

[0017] FIG. 2 schematically illustrates an exemplary structure of a filled polymer, according to some embodiments. FIGS. 3A-3F are schematic cross-sectional side views of exemplary cushioning articles, according to some embodiments.

[0018] FIG. 4A is a schematic cross-sectional view of a portion of a cushioning article, according to some embodiments.

[0019] FIG. 4B is a schematic perspective view of a portion of a cushioning article, according to some embodiments.

[0020] FIG. 4C is a schematic cross-sectional view of a portion of a cushioning article showing two spaced apart structures, according to some embodiments.

[0021] FIG. 5A a schematic illustration of the compression of a multilayer stack of cushioning articles, according to some embodiments.

[0022] FIG. 5B is a schematic illustration of a compression force deflection curve (CFD), according to some embodiments.

[0023] FIGS. 6A-6D are schematic top-down views of exemplary battery assemblies including at least one cushioning article or fdm between adjacent battery cells, according to some embodiments.

[0024] FIGS. 7A-7D are schematic top-down views of exemplary battery assemblies including two or more cushioning articles or fdms, according to some embodiments.

[0025] FIGS. 8A-8B are images of a silicone foam and an exemplary predominantly solid ablative silicone elastomer, respectively, after torch testing.

[0026] FIG. 9 shows an exemplary cross-sectional diagram of the structured tool design for experimental examples 1-5.

[0027] FIGS. 10A-10E show optical micrographs of the structured cushioning articles for examples 1 through example 5. The scale bar below each image is 400 micrometers.

[0028] FIG. 11 shows CFD curves for the structured cushioning layers of experimental examples 1-5 and comparative example 2.

[0029] FIGS. 12A-12B show exemplary cross-sectional diagrams of structured tool designs for experimental examples 6-12.

[0030] DETAILED DESCRIPTION

[0031] In the following description, reference is made to the accompanying drawings that form a part hereof and in which various embodiments are shown by way of illustration. The drawings are not necessarily to scale. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present description. The following detailed description, therefore, is not to be taken in a limiting sense.

[0032] Automotive electrification is currently one of the biggest trends in the automotive industry. Within this trend, the propulsion of electric energy supplied by electric batteries and the development of suitable electric vehicle batteries as energy storage devices are the main focus in the automotive industry. Electric-vehicle batteries are used to power the propulsion system of battery electric vehicles (BEVs) and hybrid electric vehicles (HEVs). These batteries, which are typically lithium-ion batteries, are designed with a high ampere hour capacity. The trend in the development of electric vehicle batteries goes to higher energy density in the battery (kWh / kg) to allow the covering of longer distances and to reducing charging times of the battery.

[0033] Due to the high energy density of electric vehicle batteries and the high energy flow during charging or discharging of the battery, there is a risk of creation of hot spots and thermal runaway events where the heat generated by the decomposition of battery cells propagates very rapidly to neighboring cells. This chain reaction might lead to the explosion or the fire catching of the whole electric vehicle.

[0034] Moreover, during the normal life cycle of these energy storage devices, in particular during fast charging and discharging cycles of electric vehicle batteries, the battery cells used for such battery modules tend to expand and contract continuously. These expansion / contraction cycles can put the battery cells under considerable pressure conditions, which in turn may lead to mechanical damage of the battery cells.

[0035] In that context, the use of thermal management solutions has rapidly emerged as one way to mitigate the temperature rise in battery assemblies. Desired attributes for suitable cushioning and insulation solutions include caliper uniformity, high temperature stability, low thermal conductivity, and break through resistance under the extreme conditions of thermal runaway events. In addition, solutions which are simplified from a design and manufacturing perspective are desired to address performance and cost expectations for BEV applications.

[0036] One approach is disclosed in U.S. Pat. Appl. Pub. No. 2007 / 0259258 (Buck) which describes the use of heat absorbing material to absorb the heat generated by the battery cells of a battery pack assembly and transfer heat out from the case of the assembly thereby maintaining a lower temperature inside each battery pack and the overall battery assembly. Another approach is described in U.S. Pat. Appl. Pub. No. 2019 / 0393574 (Goeb et al.) which discloses the use of thermally conductive gap filler compositions comprising thermally conductive filler material for cooling battery assemblies. Still another approach is described in U.S. Pat. Appl. Pub. No. 2016 / 0308186 (Han), which discloses a battery module including battery cells arranged adjacent to each other along a first direction, a spacer between neighboring battery cells, and a multi-layer insulation sheet between the neighboring battery cells together with the spacer, where the multi-layer insulation sheet includes a plurality of insulation layers extending in parallel with the surfaces of the battery cells.

[0037] Furthermore, maintaining battery cell pressure and pressure uniformity for pouch and prismatic cells during the volume change of charge-discharge cycles is desired for battery life and failure mode avoidance. As a result, there is a need for cushioning materials that provide an expanded Compression Force Deflection (CFD) plateau, where the force (stress) that the cushioning material exerts on the battery cell is relatively uniform over a wide range of compression levels (strain) for the expected 10-year life of the battery. For example, a CFD plateau stress of at least 100 kPa (e.g., 100 to 5000 kPa) may be desired in solid state battery cells to maintain contact between the solid electrolyte and electrodes. A CFD plateau stress of at least 150, 200, 250, 300, 400, 500, 600, 800, 1000, 1200 kPa may be desired for some solid- state battery cells. In addition, there is a desire for a CFD plateau range of extending at least from 15 to 35% strain to improve reliability and give a larger working range. A CFD plateau can have a stress that varies somewhat with compression, but the variation with compression is at a substantially lower rate than that of regions of the stress-compression curve on each side of the CFD plateau.

[0038] According to some embodiments of the present description, it has been found that a cushioning article or fdm including suitable structures extending from a base layer along a thickness direction of the cushioning article or fdm can provide desired cushioning performance (e.g., a desired CFD plateau stress and width). The suitable structures are typically generally tilted with a curved top portion in order to facilitate further tilt and bend over of the structures when the fdm is compressed. In some embodiments, the structures of cushioning article or fdm provide a cushioning effect primarily by bending rather than compression. That is, there may be little volume change of the structures as they bend, and the bending of the structures provides most or substantially all of the cushioning provided by the article or fdm. The structures may also have a sidewall with a hinge region where the slope of the side wall changes relatively rapidly to further facilitate the bending of the structures. The structures extending from the base layer along the thickness direction can be described as protruding from the base layer.

[0039] In some embodiments, a cushioning article is provided. The cushioning article may have desired thermally insulating properties. A cushioning article may be in the form of a fdm and may be referred to as a cushioning fdm. A cushioning article or fdm can include one or more structured cushioning layers and may optionally include a substrate. The cushioning layers of the present description may be designed, according to some embodiments, such that a predominately solid, but structured layer is made using high temperature and thermal stable materials such that insulating properties and low thermal conductivity can be achieved with a material that also provides breakthrough resistance in thermal runaway events. Such performance in traditional EV battery assemblies is achieved through the use of composite constructions which comprise an assembly of multiple materials to provide both insulating and thermal runaway blast barrier properties. The asymmetric structures of the present description may provide for improved mechanical deformation via a purposely designed shape which leads to a more controlled bending of the structure under compression, according to some embodiments.

[0040] Figures 1A-1C are schematic perspective views of three example battery module assemblies that include three different insulating cushioning layer options between battery cells, according to some embodiments. The illustrated arrangements of the battery cells are known in the art and are generally described in U.S. Pat. Appl. Pub. No. 2023 / 0159718 (Kempf et al.), for example. Any of the cushioning articles or fdms of the present description may be placed between the adjacent battery cells of these figures. For example, cushioning articles 150 in these figures can be or include a cushioning article of the present description although the structures are not shown in these figures.

[0041] Figure 1A illustrates an exemplary generic assembled battery module 100 which includes a plurality of electrochemical cells or battery cells 160 separated from each other by a gap, and a plurality of cushioning articles 150 positioned in the gap between the battery cells 160, according to some embodiments. In some embodiments, the battery module is further provided with a base plate 180 upon which is positioned a thermally conductive gap fdler 170. Figure 1A shows a battery assembly where the cushioning article includes a cushioning layer 150 having two major surfaces which contact adjacent battery cells 160.

[0042] Figure IB illustrates an exemplary generic assembled battery module 100 which includes a plurality of battery cells 160 separated from each other by a gap, and a plurality of composite or multilayer cushioning articles 150 positioned in the gap between the battery cells 160, according to some embodiments. In some embodiments, the battery module is further provided with a base plate 180 upon which is positioned a thermally conductive gap fdler 170. The cushioning article 150 may include a predominantly inorganic layer 155, which may be designed to provide additional thermal insulation and thermal stability benefits, with cushioning layers 154 positioned on either side of the predominantly inorganic layer 155. Each of the cushioning layers has two major surfaces, one contacting the predominantly inorganic layer 155 and the other one contacting an adjacent battery cell 160.

[0043] Figure 1C illustrates another exemplary generic assembled battery module 100 which includes a plurality of battery cells 160 separated from each other by a gap, and a plurality of composite or multilayer cushioning articles 150 positioned in the gap between the battery cells 160, according to some embodiments. In some embodiments, the battery module is further provided with a base plate 180 upon which is positioned a thermally conductive gap fdler 170. The cushioning article 150 can include a predominantly inorganic layer 155, which may be designed to provide additional thermal insulation and thermal stability benefits, with a cushioning layer 154 such that an asymmetric multilayer cushioning article 150 is positioned between adjacent battery cells. The cushioning layer 154 has two major surfaces, one contacting the predominantly inorganic layer 155 and the other contacting a battery cell 160. The predominantly inorganic layer 155 contacts the cushioning layer 154 with one of its major surfaces and an adjacent battery cell 160 with its opposite major surface.

[0044] Polymeric foam layers have conventionally been used for the cushioning layers 150, 154, but it has now been found, according to some embodiments, that a non-foam structured cushioning layer can advantageously be used for the cushioning layer(s), where the structures, when formed of a suitable material, provides the desired cushioning effect.

[0045] Figure 2 schematically illustrates a material 250 that may be used in the cushioning layers 150, 154, according to some embodiments. The material 250 typically includes a continuous phase of organic polymer 259 and may include a discontinuous phase (e.g., particles or fibers) 251, 252 dispersed therein. For conventional foams, the discontinuous phase 251 is typically air or other gas (e.g., items 251 are conventionally gas filled pockets or pores). Polymeric foam insulation layers while providing good thermal conductivity typically do not provide robust thermal protection and high heat flame resistance in the event of over-heating battery cells and need to be used in conjunction with other heat resistance and penetration resistant inorganic layers like mica, stainless steel, alumina sheet, and the like to provide suitable performance in thermal runaway events. However, according to some embodiments of the present description, the elements 251 can be or include solid fdler and the compressibility of the cushioning article can arise from utilizing a structured major surface having suitably shaped structures even when the material 250 is largely incompressible (compared to typical foams). In some embodiments, the material 250 can further include hollow particles 258 and / or entrapped air 257, for example. The hollow particles 258 can include a shell 253, which may be an inorganic shell. For example, the shell 253 can be or include glass. In some embodiments, the hollow particles 258 are or include glass bubbles or glass microspheres. Glass microspheres can have an average diameter in a range of about 10 micrometers to about 300 micrometers, or about 12 micrometers to about 200 micrometers, or about 15 micrometers to about 100 micrometers, for example.

[0046] In some embodiments, as described further elsewhere herein, a cushioning article (e.g., 350, 450) includes a plurality of structures (e.g., 352a, 452a) disposed on a base layer (e.g., 358, 420) of the cushioning article. In some embodiments, the structures comprise a solid material at no less than 60, 70, 80, 90, 95, 96, 97, 98, 99 volume percent based on a total volume of the structures. For example, the solid material portion of the material 250 includes polymer 259, solid fdler 251, 252, and solid shell material of hollow particles 258, but would not include gas in the hollow particles 258 or entrapped air 257. The solid material can comprise a cross-linked silicone elastomer and solid fdler dispersed therein. In some embodiments, the structures comprise hollow particles 258 dispersed in the cross-linked silicone elastomer (e.g. at 10 to 55 volume percent based on a total volume of the structures). In some embodiments, the structures comprise air 257 entrapped in the in the cross-linked silicone elastomer at no more than 20, 15, 12, 10, 8, 6, 5, 4, 3, 2, or 1 volume percent based on the total volume of the structures. In some embodiments, the solid material comprises the solid fdler 251, 252 at no less than 10, 15, 20, 25, 30, 35, 40, 45, 50, or 55 volume percent based a total volume of the solid material. In some such embodiments, or in other embodiments, the solid material comprises the solid fdler 251, 252 at no more than 64, 60, 55, 50, or 45 volume percent based a total volume of the solid material. For example, in some preferred embodiments, the solid material comprises the solid fdler 251, 252 at 10 to 50 volume percent or at 15 to 45 volume percent. In some embodiments, the solid fdler 251, 252 comprises fdler selected from the group consisting of particles 251, fiber 252, and combinations thereof. The particles 251 can be substantially spherical, ellipsoidal, or irregular, for example. In some embodiments, the solid fdler comprises (e.g., carbon) fibers that may have an average length in a range of about 3 mm to about 30 mm, or about 5 mm to about 28 mm, or about 6 mm to about 26 mm. In some embodiments, the solid fdler comprises silica and / or alumina (aluminum trihydrate). In some embodiments, the solid fdler is selected from the group consisting of silica, alumina, silicon carbide, carbon fibers, and combinations thereof. Other useful solid fdler is described further elsewhere herein.

[0047] In some embodiments, the structures comprise a cross-linked silicone elastomer 259 and fdler dispersed therein, where the fdler includes solid fdler material 251 and hollow particles 258. In some embodiments, the structures comprise no less than 40, 50, 60, 70, 80, or 90 volume percent solid material based on a total volume of the structures. In some embodiments, the structures comprise the fdler at no less than 10, 15, 20, 25, 30, 35, 40, 45, 50, or 55 volume percent based a total volume of the structures. In some such embodiments, or in other embodiments, the structures comprise the fdler at no more than 64, 60, 55, 50, or 45 volume percent based a total volume of the structures. In some embodiments, the structures comprise the solid fdler material at no less than 10, 15, 20, 25, 30, 35, 40, 45, 50, or 55 volume percent based a total volume of the structures. In some embodiments, the structures comprise the hollow particles 258 at no less than 10, 20, 30, 40, or 50 volume percent based a total volume of the structures. In some embodiments, the structures comprise each of the solid fdler material and the hollow particles at no less than 10 volume percent based on a total volume of the structures, and comprise the solid fdler material and the hollow particles at no more than 55 volume percent in total based on the total volume of the structures.

[0048] The base layer (or land region) can be made of the same material as the structures and so can have the same composition (e.g., a same loading of solid fdler and hollow particles if included). In some embodiments, a unitary (monolithic) fdm comprises the structures and the base layer. In some embodiments, the unitary fdm is disposed on a polymeric substrate having a composition different from that of the unitary fdm.

[0049] According to some aspects of the present description, an approach to making a single composition material is described which has the benefits of high heat and flame resistance of inorganic layered materials, while also being able to provide resilient cushioning behavior (which may be similar to, or better than, that of polymeric foam layers, for example) in a predominately solid elastomeric material through the incorporation of microstructured surface features and microstructured solid cushioning layer assemblies.

[0050] Figures 3A through 3F are schematic cross-sectional views of various embodiments of cushioning article or fdm 350. The structures (e.g., 352a) are typically arranged along a width (x- direction) of the cushioning article and extend along a length (y-direction) of the cushioning article. The structures can be prismatic structures having a substantially same cross-section along substantially an entire length of the cushioning article.

[0051] An illustrative embodiment of the surface structured cushioning article 350 is shown in Figure 3 A. The structured cushioning article 350 has a major surface 351 (which includes the top outer surface of land 359 and structures 352a) that can include a series of repeating asymmetric fin-shaped structures 352a. The structures 352a can define a surface 352 connecting to the tops of the outermost portions of the structures 352a, where the surface 352 may be planar when the cushioning article is laid flat. The structures 352a can have at least some facets or surfaces 352b and 352c that are non-parallel and nonperpendicular to the surface 352. The structures 352a of the first major surface are spaced apart and have gaps between them with predominantly flat regions parallel to the surface 352. A pitch of the fin-like structures (repeat distance) is p2 and a width of the individual structures is pi. The width can be understood to be a maximum width of the structure, unless indicated differently. The ratio p? / p i can be from 1 to about 10, or from about 2 to about 8, or from about 2 to about 6. or from about 2 to about 4. The first major surface has shapes (e.g., linear asymmetric fin-shaped structures) where the height of the structures is hl, and a height or thickness of a land region 358 (layer from which the structures 352a extend, which may be referred to as a base layer) of the cushioning article 350 is I12. The ratio, hi / h2 can be at least 0. 1 to about 15, or from about 0.5 to 12, or from about 1.0 to 10. The cushioning article has a total height or thickness ha. The ratio h i / lv can be at least 0.1 to about 0.99, or from 0.2 to about 0.97, or from about 0.5 to about 0.96 or from about 0.6 to about 0.95. The second major surface 353 may be nominally flat and / or non-structured and / or can have a surface roughness (e.g., Ra) of less than 5%, 4%, 3%, 2%, or 1% of the total thickness ha.

[0052] The single side structured cushioning layer of Figure 3A can also be made with a substrate layer 359 as shown in Figure 3B which is a schematic cross-sectional view of a cushioning article 350 including a cushioning layer 391 disposed on substrate layer 359, according to some embodiments. Substrate layer 359 may be used to facilitate manufacture of the cushioning article 350 and may be used to provide other useful properties to the cushioning layer, for example, enhanced dimensional stability and handleability characteristics. If used, the substrate layer in most cases is preferred to add little total thickness to the cushioning layer construction. The cushioning article includes a first major surface 351 as described further elsewhere herein. The second major surface 353 of the cushioning article 350 (which is a surface of substrate 359 in the illustrated embodiment) may be nominally flat and non-structured, with a surface roughness of less than 3% of the total thickness or in a range described elsewhere herein. In some embodiments, the substrate layer 359 may have a matte surface (e.g., surface 353).

[0053] Figure 3C shows another illustrative embodiment of a structured cushioning layer 350 of the present description, according to some embodiments. The cushioning layer 350 has opposing structured major surfaces 351 and 353 having respective structures 352a and 353a which can define respective surfaces 352 and 354 as connecting to the tops of the outermost portions of the respective structures 352a and 353a, where surfaces 352 and 354 may be planar when the cushioning article 350 is laid flat. Structures 352a and 353a can have at least some facets or surfaces 352b and 352c that are non-parallel and non-perpendicular to the respective surfaces 352 and 353. The structures 352a are spaced apart and can have gaps between them with predominantly flat regions parallel to the surface 352. Similarly, the structures 353a are spaced apart and can have gaps between them with predominantly flat regions parallel to the surface 354. The structures 352a are arranged at a pitch p2 and have a width pi as described elsewhere herein. Similarly, the structures 353a can be arranged at a pitch p4 and have a width pa. The ratio pr / p3 can be from 1 to about 10, or from about 2 to about 8, or from about 2 to about 6, or from about 2 to about 4.

[0054] The first and second major surfaces 351 and 353 can have asymmetric fin-like shapes, where the height of the respective structures are hiaand hib. The land region 358 of the cushioning article 350 can have a height or thickness I12. In some embodiments, hia / li2 is at least 0. 1 to about 15, or from about 0.5 to 12, or from about 1.0 to 10. In some embodiments, hib / h2 is at least 0.1 to about 15, or from about 0.5 to 12, or from about 1.0 to 10. The total height of the structures is hi which is here defined to be hia+ hib and the total height or thickness of the cushioning article 350 is Iv. In some embodiments, the ratio h i / li- is at least 0. 1 to about 0.99, or from 0.2 to about 0.97, or from about 0.5 to about 0.96 or from about 0.6 to about 0.95. In the illustrated embodiment, the structures on the first and second major surfaces are shown as nearly aligned. In some embodiments, it may be advantageous for the structures of the two sides of the cushioning layer to be staggered with respect to one another.

[0055] The two-side structured cushioning article of Figure 3C may also be made with a substrate layer 359 as shown in Figure 3D which is a schematic cross-sectional view of a cushioning article 350 including substate layer 359 disposed between cushioning layers 391 and 392, according to some embodiments. Substrate layer 359 may be used to facilitate manufacture of the cushioning layer 350 and may be used to provide other useful properties to the cushioning layer, for example, enhanced dimensional stability and handleability characteristics. Land regions 358 and 368 are disposed on opposite sides of the substrate layer 359. If used, the substrate layer 359 in most cases is preferred to add little total thickness to the cushioning layer construction. The cushioning article 350 of Figure 3D has opposite structured major surfaces with structures that may be as described for Figure 3C. The thickness 112 of Figure 3D is the total land thickness plus the thickness of the substrate layer 359. The ratio (hia+ hib) / h2 can be as described elsewhere herein.

[0056] While shown as having the same structured surface on both sides in Figures 3C and 3D, it will be appreciated that the two structured surfaces 351 and 353 may have different shapes and / or sizes. Specific choices of structure size, shape and the alignment of structures can be determined by the desired mechanical response in application.

[0057] Figure 3E is a schematic cross-sectional view of an illustrative example of another useful embodiment of cushioning article 350, which can provide beneficial structural elements that can be used to tune the mechanical response of the cushioning layer under compression, according to some embodiments. A structured cushioning layer 350 having fin-shaped structures having two different sizes is shown. A first major surface 351 of the cushioning layer 350 includes structures 352a which can define a surface 352 as connecting to the tops of the outer most portions of the structures 352a, where the surface 352 may be planar when the cushioning article 350 is laid flat. The structures 352a can have at least some facets or surfaces 352b and 352c that are non-parallel and non-perpendicular to the surface 352. The structures 352a of the first major surface are typically spaced apart and have gaps between them with predominantly flat regions parallel to the surface 352. The pitch (repeat distance) of the structures 352a is p? and the width of the individual structures is pi. The ratio p? / p i can be from 1 to about 10 or can be in any ratio described elsewhere herein for the structures 352a of other embodiments. The structures 352a have a height hi and the land region 358 (or base layer) has a height l . The ratio h2 / h 1 can be at least 0.1 to about 0.99 or can be in any range described elsewhere herein for the structures 352a of other embodiments. The cushioning article 350 has a total height or thickness ha. The ratio h i / h- can be at least 0.1 to about 0.99 or can be in any range described elsewhere herein for the structures 352a of other embodiments.

[0058] In some embodiments, the major surface 351 includes a second set of fin-shaped structures 357a which can define a second surface 357 connecting to the tops of the outer most portions of the structures 357a, where the second surface 357 may be planar when the cushioning article is laid flat. The structures 357a can have at least some facets or surfaces 357b and 357c that are non-parallel and non-perpendicular to the surface 357. The structures 357a are typically spaced apart and have gaps between them with predominantly flat regions parallel to the first major surface 357. The pitch (repeat distance) of the structures 357a is p4 and a width of the individual structures is p3. The ratio p p3 can be from 1 to about 10, or from about 2 to about 8, or from about 2 to about 6, or from about 2 to about 4. In some embodiments, the pitch pz of the larger structures 352a is close to the pitch p4 of the smaller structures 357a such that the ratio of |>2 to p4 is about 1 with a variability of about + / - 0.2. The height I14 of the structure 357a is smaller than the height hi of the structures 352a and the ratio hi / tu can be in a range of from about 1.1 to about 4 or from about 1.2 to about 3.5, or from about 1.5 to about 3. A total height of the structures 357a and the land layer is hs. The ratio tu / hs can be at least 0. 1 to about 0.99, or from 0.2 to about 0.97, or from about 0.5 to about 0.96, or from about 0.6 to about 0.95.

[0059] The two-side structured cushioning layer of Figure 3E can also be made with a substrate layer 359 as shown in Figure 3F which is a schematic cross-sectional view of a cushioning article 350 including a cushioning layer 391 disposed on substrate layer 359, according to some embodiments. Substrate layer 359 may be used to facilitate manufacture of the cushioning layer 350 and may be used to provide other useful properties to the cushioning layer, for example, enhanced dimensional stability and handleability characteristics. If used, the substrate layer in most cases is preferred to add little total thickness to the cushioning layer construction. The widths pi and p?. the pitches p? and p4 and the heights hi and hi can be as described for Figure 3E. The heights hi. I13, and h, can be as described for Figure 3E except that these heights include the thickness of the substrate layer 359 in Figure 3F. Any of the ratios of any of the length scales to any other of these length scales for the embodiment of Figure 3F can be in any of the ranges described for the embodiment of Figure 3E. For example, the ratio p? / p 1 can be from 1 to about 10 or can be in any ratio described elsewhere herein; the ratio fo / hi can be at least 0.1 to about 0.99 or can be in any range described elsewhere herein; the ratio hi / 113 can be at least 0. 1 to about 0.99 or can be in any range described elsewhere herein; and / or the ratio h | / h4can be in a range of from about 1.1 to about 4 in any range described elsewhere herein. A total height of the structures 357a and the land layer is hs. The ratio tu / hs can be at least 0.1 to about 0.99, or from 0.2 to about 0.97, or from about 0.5 to about 0.96, or from about 0.6 to about 0.95.

[0060] Utilizing different structure sizes and / or different structure shapes can provide different handles for tuning mechanical response (e.g., stress) as a function of compression (e.g., strain). While Figures 3E and 3F show illustrative examples with two different sizes of structures having a generally same shape, in other examples three or more different sizes are utilized and / or different shapes are utilized. Additionally, Figures 3E and 3F schematically show that there are two smaller structures 357a between each pair of larger structures 352a. However, in other embodiments, a different (e.g., 1, or less than 1 on the average, or more than 2) number of smaller structures is disposed between pairs of larger structures. A ratio of a number ratio of larger structures 352a to a number of smaller structures 357a can be in the ratio of from 1: 1 to about 10: 1, or from 1: 1 to 7: 1, or from 1: 1 to 4: 1.

[0061] The cushioning articles, or at least the structures of the cushioning articles, may be made of a predominately solid material such as a predominately solid silicone material (e.g., an ablative silicone with solid filler particles dispersed therein). Suitable materials for making the cushioning articles 350 are described further below.

[0062] In some embodiments, a (e.g., predominately solid) silicone cushioning layer of the present description comprises silicone elastomers, in particular silicone rubbers, more particularly organopolysiloxane polymers which can be further polymerized into crosslinked elastomers. The organopolysiloxane materials of the present description are in many cases (e.g., highly) filled with organic and / or inorganic fillers to provide desired thermal and ablative performance properties of the cured resin which make up the solid portion of the cushioning layers described herein. These fillers will be described in more detail elsewhere herein.

[0063] In some embodiments, the cushioning layer (e.g., structures plus base layer or land) is a filled silicone rubber layer. In some embodiments, the filled silicone rubber layer is obtainable from a curable precursor of the silicone rubber layer, in particular a thermally curable precursor composition. Precursor compositions of the filled silicone rubber for use herein are not particularly limited but are preferably curable and meet the desired thermal performance properties and retain suitable elastomeric properties such that the material demonstrates the proper mechanical deformation and recovery properties desired. Any curable precursors of a silicone rubber commonly known in the art of ablative silicone materials may be used in cushioning layers of the present description which may be used in electric battery assemblies, for example. Suitable curable precursors of a silicone rubber for use herein may be easily identified by those skilled in the art in the light of the present description. In some embodiments, the precursor of the silicone rubber layer for use herein is a two-part composition.

[0064] In some embodiments, the two-part precursor composition of the silicone rubber layer is selected from the group consisting of addition curing type two-part silicone compositions, condensation curing type two-part silicone compositions, and any combinations or mixtures thereof. In some preferred embodiments, the precursor of the silicone rubber for use herein comprises an addition curing type two- part silicone composition, such as an addition curing type two-part organopolysiloxane composition. Suitable addition curing type two-part organopolysiloxane compositions for use herein as the precursor of the silicone rubber compositions may be easily identified by those skilled in the art.

[0065] According to some preferred embodiments, the precursor of the silicone rubber for use herein comprises at least one organopolysiloxane compound A having aliphatic unsaturation; at least one organohydrogenpolysiloxane compound B comprising silicone bonded hydrogen, with at least two silicone bonded hydrogens per molecule, or at least three or more silicone bonded hydrogen atoms per molecule; and an effective amount of a curing catalyst C, such as a platinum-based curing catalyst.

[0066] In some embodiments, the at least one organopolysiloxane compound A having aliphatic unsaturation has the following formula: where:

[0067] R and R", are independently selected from the group consisting of Cl to C20 hydrocarbon groups, and in particular R can be an alkyl group chosen from the group consisting of methyl, ethyl, propyl, trifluoropropyl, and phenyl, and optionally R is a methyl group;

[0068] R' is a C 1 to C20 alkenyl group, and in particular R' can be chosen from the group consisting of vinyl, allyl, hexenyl, decenyl and tetradecenyl, and more in particular R' can be a vinyl group; and n is an integer having a value in a range from 5 to 5000, or from 5 to 2000 and in particular from 5 to 500.

[0069] In some embodiments, R" is an alkyl group such as a methyl, ethyl, propyl, trifluoropropyl, phenyl, and in particular R" can be a methyl group.

[0070] In some exemplary aspects, the at least one organopolysiloxane compound A comprises 2 or more alkenyl functional polyorganosiloxanes polymers. Multiple alkenyl functional polyorganosiloxanes polymers can be used to modify or target certain silicone elastomer properties while having the ability to adjust the viscosity of the silicone resin formulation as needed.

[0071] The organohydrogen polysiloxane Compound B comprising silicone bonded hydrogen typically are selected from a group of alkylhydrosiloxane-dimethylsiloxane copolymers that are trimethylsiloxy terminated. The alkyl groups can be selected from the group consisting of Cl to C20 hydrocarbon groups, and in particular the alkyl group can be chosen from the group consisting of methyl, ethyl, propyl, trifluoropropyl. Most commonly the alkyl groups are methyl. Structures of the commonly used methyl hydrosiloxane-dimethylsiloxane copolymers can be found from many suppliers. For example, Gelest, Inc. (Morrisville, PA) makes a variety of such copolymers having a molecular weight ranging at least from 900 g / mole to 60,000 g / mole. Examples of useful organohydrogen polysiloxanes include those having a CAS Number 68037-59-2.

[0072] In exemplary formulations of the cushioning article of the present description, the cushioning layer is made from the crosslinking of siloxane polymers and the siloxane formulation contains additional additives / fillers which are beneficial to providing the desired thermal performance and stability of the material for a given application.

[0073] In some embodiments, the cushioning layer further comprises an additional additive which is selected from the group consisting of flame retardants, colorants, pigments, rheology modifiers, thixotropic agents, surface additives, flow additives, nanoparticles, antioxidants, reinforcing agents, toughening agents, silica particles, glass or synthetic fibers, thermally insulating particles, electrically conducting particles, electrically insulating particles, infrared opacifier particles, and any combinations or mixtures thereof.

[0074] In some embodiments, a non-flamable and flame retardant additive that may be dispersed in the silicone materials is selected from the group consisting of aluminum hydroxide, magnesium hydroxide, magnesium carbonate, huntite, hydromagnesite, huntite-hydromagnesite, nesquehonite and calcium carbonate.

[0075] In some embodiments, a non-flammable filler material that may be dispersed in the silicone material is selected from the group consisting of mineral fibers, silicate fibers, ceramic fibers, asbestos fibers, carbon fibers, aramid fibers, and any combinations or mixtures. Such fibers can be used with varying fiber length and in some embodiments the fibers are chopped into short lengths of from about 10mm to about 50mm in length, for example. In some preferred embodiments, the non-flammable filler material comprises mineral fibers. It has been found, according to some embodiments, that a polymer (e.g., silicone rubber) with mineral fibers dispersed therein have excellent thermal resistance and thermal stability characteristics, as well as improved resistance to surface cracking and surface brittleness even after prolonged exposure to temperatures up to 600° C. Without wishing to be bound by theory, it is believed that these beneficial characteristics are due in particular to the excellent compatibility of the mineral fibers (in particular silicate fibers) with the surrounding polymeric matrix (in particular silicone polymer matrix), which participates in densifying and mechanically stabilizing the resulting matrix.

[0076] In some embodiments, the non-flammable filler material is comprised in the cushioning layer in an amount ranging from 0.5 to 50 wt.%, 0.5 to 40 wt. %, from 1 to 30 wt. %, from 1 to 20 wt. %, from 1 to 10 wt. %, from 1 to 8 wt. %, from 2 to 8 wt. %, from 2 to 6 wt. %, or even from 3 to 6 wt. %, based on the overall weight of the precursor composition used for making the cushioning layer.

[0077] In some embodiments, the cushioning layer may further include closed shell glass bubbles having densities of less than about 0.5 g / cm3, or less than about 0.4 g / cm3or less than about 0.35 g / cm3or less than about 0.32 g / cm3, or even less than about 0.25 g / cm3, or less than about 0.2 g / cm3. Suitable glass bubbles can be sourced from manufacturers such as 3M Company (St Paul, MN). If used, these glass bubbles may be present in amounts such that the void volume of the glass bubbles in the cushioning layer is no greater than about 40 volume percent or no greater than about 30 volume percent or no greater than about 20 volume percent or no greater than about 15 volume percent, for example.

[0078] In some embodiments, the cushioning layer may further comprise closed shell polymeric bubbles having densities of less than about 0.7 g / cm3, or less than about 0.65 g / cm3, or less than about 0.6 g / cm3, or less than about 0.55 g / cm3, or less than about 0.5 g / cm3, or less than about 0.4 g / cm3, or less than about 0.3 g / cm3, or less than about 0.2 g / cm3, or even less than about 0.1 g / cm3. Such polymeric bubbles are typically thermoplastic materials and available from manufacturers such as Nouryon under the tradename EXPANCEL and Chase Corporation under the tradename DUALITE. If used, these bubbles may be present in amounts such that the void volume of the bubbles in the cushioning layer is no greater than about 40 volume percent, or no greater than about 30 volume percent, or no greater than about 20 volume percent, or no greater than about 15 volume percent.

[0079] In some embodiments, the silicone may comprise void content from air entrained during processing of the silicone.

[0080] In some embodiments, the predominantly solid silicone cushioning layer is substantially free (e.g., no more than 2, 1, or 0.5 volume percent) of substantially thermally conductive fdlers (e.g., fillers having a thermal conductivity of at least twice that of the silicone material).

[0081] In some embodiments, the cushioning layer (excluding the void fraction produced and defined by the structured surface as described for Figures 3A-3F, 5A, 6A-6D, and 7A-7D) has a density no less than 0.6 g / cm3, no less than 0.65 g / cm3, no less than 0.7 g / cm3, or no less than 0.8 g / cm3. In some embodiments, the cushioning layer (excluding the void fraction produced and defined by the structured surface as described for Figures 3A-3F, 5A, 6A-6D, and 7A-7D) has a density in a range from 0.5, 0.55, or 0.6 to 1.5 g / cm3, from 0.65 to 1.4 g / cm3, from 0.7 to 1.3 g / cm3, from 0.7 to 1.2 g / cm3, or from 0.8 to 1.15 g / cm3.

[0082] When the void fraction produced by structuring of the surface of the predominately solid silicone cushioning layer is accounted for as described in Figures, the bulk density of the cushioning layer or assembly of cushioning layers (see, e.g., Figures 7A-7D) can be in a range from 0. 1 to 0.9 g / cm3, from 0.12 to 1.0 g / cm3, from 0.15 to 0.9 g / cm3, from 0.15 to 0.8 g / cm3, or from 0.2 to 0.7 g / cm3. In this case, the densities of the component materials remain the same, but the bulk density of the article decreases due to incorporation of void space from the structured surface. For example, refereeing to Figure 3 A, the bulk density refers to the mass of the cushioning layer 350 divided by the volume between the surfaces 352 and 353.

[0083] In some embodiments, the cushioning article includes a substrate layer which is substantially permanently bonded to the silicone layer(s) (see, e.g., Figures 3B, 3D, and 3F). Any suitable substrate may be used. Useful substrates may include but are not limited to polyesters, polyamides, polyimides, and other high temperature engineering polymeric substrates whether made by thermoplastic or thermoset means. Substrates which have excellent high temperature thermal stability and / or good to excellent flammability ratings are preferrable, for example, V0 rating when measured according to the UL-94 standard flammability test method.

[0084] Figures 4A-4C schematically illustrate further details of the structures 452a of cushioning articles, according to some embodiments. Structures 452a may correspond to structures 352a, 357a (when cushioning layers including second structures), and / or 353a (for two sided cushioning layers) of cushioning articles 350. Figure 4A is a schematic cross-sectional view of a portion of a cushioning article or film 450 including a structure 452a on a base layer 420, according to some embodiments. Figure 4B is a schematic top perspective view of a portion of a cushioning article or film 450, according to some embodiments. Figure 4C is a schematic cross-sectional view of a portion of a cushioning article or film 450 including spaced apart structures 452a on a base layer 420, according to some embodiments.

[0085] In some embodiments, a cushioning article 450 includes a plurality of structures 452a disposed on a base layer 420 of the cushioning article 450 where the structures 452a are arranged along a width of the cushioning article and extend along a length of the cushioning article 450. The cushioning article 450 can define a length direction (y-direction) along the length of the cushioning article, a width direction (x- direction) along the width of the cushioning article, and a thickness direction (z-direction) along the thickness of the cushioning article, where the width, length and thickness directions are mutually orthogonal. The cushioning article can be or include a film. For example, the structures 452a and base layer 420 can be a film layer that may be disposed on a film substrate, for example. In some embodiments, each structure 452a includes opposing first and second sidewalls 411 and 412 extending along a thickness direction (z-direction) of the cushioning article 450 from the base layer 420 to a curved top portion 425 of the structure 452a, where the curved top portion 425 is concave towards the base layer 420 and extends between and connects the first and second sidewalls 411 and 412. In some embodiments, at least a portion of the curved top portion 425 has a radius of curvature in a range of about 20 to 1000 micrometers, or about 30 to 800 micrometers, or about 40 to 600 micrometers, or about 50 to 500 micrometers, or about 50 to 400 micrometers. In some embodiments, at least a portion of the curved top portion 425 of the structure has a radius of curvature in a range of about 0.05 to about 0.5, or about 0.05 to about 0.4, or about 0.06 to about 0.35, or 0.07 to about 0.3, or about 0.08 to about 0.28, or about 0.08 to about 0.26 times a height hi (or H) of the structure. The second sidewall 412 includes first and second portions 413 and 414, where the first portion 413 is between the base layer 420 and the second portion 414, and the second portion 414 is between the first portion 413 and the curved top portion 425. In some embodiments, in a first cross-section (xz -cross section) that is orthogonal to the length of the cushioning article and / or parallel to the width of the cushioning article: the first and second side walls 411 and 412 make respective first and second angles al and a2 with a same first direction (x-direction) along the width of the cushioning article 450. In some embodiments, the first sidewall 411 and each of the first and second portions 413 and 414 of the second sidewall 412 slope toward one another in a direction from the base layer to the top portion 425 of the structure 452a. Slopes of the sidewalls can be measured, for example, from optical images, or scanning electron micrography (SEM) images, of the structures 452a in the first cross-section.

[0086] In some embodiments, a monolithic film (e.g., corresponding to cushioning layer 391 and / or 392) comprises the plurality of structures 452a and the base layer 420. For example, the structures 452a can be formed in an extrusion replication process and the base layer 420 may be a land layer integrally formed with the structures 452a in that process. Alternatively, a monolithic film may be formed in a cast and cure process using thermoset materials where an uncured thermoset resin can be cast onto a heated tool or cast onto a structured film tool with the appropriate inverse structure to the one desired. The thermoset resin can be polymerized and crosslinked to produce the cushioning article 450.

[0087] In some embodiments, a cushioning article (e.g., 350, 450) includes a plurality of structures (e.g., 352a, 452a) disposed on a base layer (e.g., 358, 420) of the cushioning article where the structures are arranged along a width (x-direction) of the cushioning article and extend along a length (y-direction) of the cushioning article. Each structure includes opposing first and second sidewalls 411 and 412 extending along a thickness direction (z-direction) of the cushioning article from the base layer to a curved top portion 425 of the structure, such that in a first cross-section (xz -plane) orthogonal to the length of the cushioning article and for each structure of the plurality of structures, the curved top portion 425 is concave toward the base layer and at least portions of each of the first and second sidewalls 411 and 412 are tilted toward a same first direction (+x-direction) along the width of the cushioning article.

[0088] In some embodiments, for each structure of the plurality of structures: the first and second sidewalls 411 and 412 make respective first and second angles al and a2 with the same first direction along the width of the cushioning article, where the first angle al is greater than 40 degrees and less than 90 degrees along substantially an entire length of the first side wall 411, and the second angle a2 is in a range of 90 to 150 degrees along substantially an entire length of a first portion 413 of the second sidewall and is in a range of 70 to 89.5 degrees along substantially an entire length of a second portion 414 of the second sidewall 412. The first portion 413 is disposed between the base layer and the second portion 414, and the second portion 414 is disposed between the first portion 413 and the curved top portion 425. The length of the second portion 414 can be greater than the length of the first portion 413. In some embodiments, for each structure of the plurality of structures, the length of the second portion 414 of the second sidewall 412 is at least 2 times the length of the first portion 413 of the second side wall 412. In some embodiments, for each structure of the plurality of structures, a total length (LI + L2, see, e.g., FIG. 4C) of the first and second portions of the second sidewall is at least 80% of a total length (Lt; see, e.g., FIG. 4C) of the second sidewall 412. In some embodiments, for each structure of the plurality of structures, the second angle changes between the first and second portions of the second sidewall to define a hinge region 440, where the first portion 413 of the second side wall 412 extends from the base layer (e.g., 420) to the hinge region 440 and the second portion 414 of the second sidewall 412 extending from the hinge region 440 to the curved top portion 425. In some embodiments, for each structure of the plurality of structures and for each distance Z1 (see, e.g., FIG. 4A) above the base layer 420 between the base layer and the curved top portion 415 , the second angle a2 is greater than the first angle a 1. In some embodiments, each structure of the plurality of structures, a minimum value of the second angle is greater than a maximum value of the first angle. In some embodiments, the structures have an average height H (which may also or alternatively be denoted hi) from the base layer 420 to atop 428 of the structures and are arranged at an average pitch P (which may also or alternatively be denoted pi) along the first direction. In some embodiments, 7 H > P > H / 2. In some embodiments, an average of a maximum width of the structures along the first direction is W (which may also or alternatively be denoted pi). In some embodiments, 4 > H / W > 1. In some embodiments, the average height H is at least 50, 100, 200, 300, or 400 micrometers. In some such embodiments, or in other embodiments, the average height H is no more than 15, 12, 10, 8, 6, 4, or 2 mm. For example, in some embodiments, the average height H is in a range of 50 micrometers to 15 mm, or 100 micrometers to 12 mm, or 200 micrometers to 10 mm, or 300 micrometers to 4 mm, or 400 micrometers to 2 mm, or 100 micrometers to 2 mm, or 50 micrometers to 2 mm.

[0089] The aspect ratio (ratio of height H (or hi) to width W (or pi); see, e.g., Figure 4C) may be adjusted to adjust the CFD plateau, for example (see, e.g., Figure 5C). A lower aspect ratio H / W in may be useful for increasing the CFD plateau stress, but a greater number of cushioning articles or films may be needed to give a desired total deflection when a lower aspect ratio is utilized. In some embodiments, the structures 452a have an average height H from the base layer 420 to a top 428 of the structures 452a and an average of a maximum width of the structures 452a (e.g., unweighted mean of the widths of the structures 452a at the base layer 420) along the first direction is W, where 4 > H / W > 1. In some such embodiments, or in other embodiments, H / W is less than or equal to 3.5, 3, or 2.5. In some such embodiments, or in other embodiments, H / W is greater than or equal to 1.25, 1.5, 1.75, or 2. For example, in some embodiments, 3.5 > H / W > 1.25, or 3 > H / W > 1.5, or 2.5 > H / W > 1.75, or 2.5 > H / W > 2. In some such embodiments, or in other embodiments, the average height H is in a range of 50 micrometers to 2 mm. In some such embodiments, or in other embodiments, the average height H is at least 75, 100, 125, 150, 200, 250, 300, or 350 micrometers. In some such embodiments, or in other embodiments, the average height H is no more than 1.75, 1.5, 1.25, 1, 0.9, 0.8, 0.7, or 0.6 mm. For example, in some embodiments, the average height H is in a range of 200 micrometers to 1.5 mm. In some preferred embodiments, the average height H is in a range of 400 micrometers to 1.5 mm.

[0090] The first angle al can be greater than 40 degrees and less than 90 degrees along substantially an entire length of the first side wall 411. The second angle a2 can change from a2a in the first portion 413 to a2b in the second portion 414. The second angle a2 can be in a range of 90 to 150 degrees along substantially an entire length of the first portion 413 and can be in a range of 70 to 89.5 degrees along substantially an entire length of the second portion 414. In some embodiments, the first angle al is at least 45, 50, 55, 60, 65, 70 degrees along substantially an entire length of the first sidewall 411. In some such embodiments, or in other embodiments, the first angle al is no more than 85, 80, 78, 76, 75 degrees along substantially an entire length of the first sidewall 411. In some such embodiments, or in other embodiments, the second angle a2 (or a2a) is at least 95, 100, 102, 104, 106, or 108 degrees along substantially an entire length of the first portion 413. In some such embodiments, or in other embodiments, the second angle a2 (or a2a) is no more than 145, 140, 135, 130, 125, 120, 115, 112, or 111 degrees along substantially an entire length of the first portion 413. In some such embodiments, or in other embodiments, the second angle a2 (or a2b) is at least 75, 80, 85, or 86 degrees along substantially an entire length of the second portion 414. In some such embodiments, or in other embodiments, the second angle a2 (or a2b) is no more than 89.4, 89.3, 89.2, 89.1, 89, 88.9, 88.8, 88.7, 88.6, 88.5, or 88.4 degrees along substantially an entire length of the second portion 414.

[0091] Substantially an entire length (e.g., of a sidewall or a portion of a sidewall) can be the entire length or the entire length except possibly for small portions where a slope has shifted due to manufacturing variations or due to other variations. Substantially an entire length generally includes at least 75% of the entire length. In some embodiments, substantially an entire length can be at least 80, 85, 90, 95, 96, 97, 98, or 99 percent of the entire length.

[0092] In some embodiments, for each structure of the plurality of structures 452a and for each distance Z1 above the base layer 420 between the base layer 420 and the curved top portion 425, the second angle a2 is greater than the first angle al . In some embodiments, for each structure of the plurality of structures 110, a minimum value of the second angle a2 is greater than a maximum value of the first angle al .

[0093] In some embodiments, the length L2 of the second portion 414 is at least 2, 3, 4, 5, 6, 7 or 8 times the length LI of the first portion 413. In some such embodiments, or in other embodiments, the length L2 is up to 50, 40, 30, 20, 15, 12, 11, or 10 times the length LI. For example, in some embodiments, the length L2 is in a range of 2 to 50, 3 to 40, 4 to 30, 5 to 20, 6 to 15, or 8 to 11 times the length LI .

[0094] In some embodiments, for each structure of the plurality of structures 452a, the second angle a2 changes between the first and second portions 413 to 414 of the second sidewall 412 to define a hinge region 440. The hinge region 440 may be radiused to provide a gradual change in slope, for example. In some embodiments, the second angle changes by at least 10 degrees over a distance along the thickness direction (z -direction) of less than 5 percent of the average height H of the structures 452aa. In some embodiments, for each structure of the plurality of structures 452a, the first portion 413 of the second sidewall 412 extends from the base layer 420 to the hinge region 440 and the second portion 414 of the second sidewall 412 extends from the hinge region 440 to the curved top portion 425. In some embodiments, atotal length (L1+L2) of the first and second portions 413 and 414 is at least 80, 85, 90, 95,96, 97, 98, 98.5, 99, or 99.5% of a total length Lt of the second sidewall 412. Lt may be greater than LI + L2 due to the (e.g., radiused) hinge region 440 contributing to a portion of the length Lt.

[0095] The structures 452a may be arranged at a pitch P (or pz) selected to be sufficiently large that the structures can bend to a desired degree without contacting one another and sufficiently small to provide a desired compression force deflection (CFD) plateau stress. In some embodiments, the structures 452a have an average height H from the base layer 420 to a top 428 of the structures 452a and are arranged at an average pitch P along the first direction. In some embodiments, 7 H > P > H / 2. In some such embodiments, or in other embodiments, 6.5, 6, 5.5, 5, 4.5, 4, 3.5, 3, 2.5 times H is greater than or equal to P. In some such embodiments, or in other embodiments, P is greater than or equal to 0.55, 0.6, 0.65, 0.7, or 0.75 times H. For example, in some embodiments, 6 H > P > 0.55 H, or 5 H > P > 0.6 H, or 4 H > P > 0.65 H, or 3 H > P > 0.7 H, or 2.5 H > P > 0.75 H. In some embodiments, the first portions 413 of the second sidewalls 412 have an average height ha along the thickness direction (z-direction). In some embodiments, ha / H is less than or equal to 0.25, 0.22, 0.20, 0.18, or 0.16. In some such embodiments, or in other embodiments, ha / H is greater than or equal to 0.02, 0.03, 0.04, or 0.05. For example, in some embodiments, 0.25 > ha / H > 0.02, or 0.22 > ha / H > 0.03, or 0.2 > ha / H > 0.04, or 0.16 > ha / H > 0.05.

[0096] In some embodiments, the second portions 414 of the second side walls 412 have an average height hb along the thickness direction. In some embodiments, hb / H is less than or equal to 0.98, 0.97, 0.96, or 0.95. In some such embodiments, or in other embodiments, h2 / H is greater than or equal to 0.75, 0.78, 0.8. 0.82, or 0.84. For example, in some embodiments, 0.98 > hb / H > 0.75, or 0.97 > hb / H > 0.8, or 0.96 > hb / H > 0.82, or 0.95 > hb / H > 0.84.

[0097] In some embodiments, for each structure 452a, the length LI of the first portion 413 of the second sidewall 412 is in a range of 0.02 to 0.5 times the total length Lt of the second sidewall 412 and the length L2 of the second portion 414 of the second sidewall 412 is in a range of 0.5 to 0.98 times the total length Lt of the second sidewall 412. In some such embodiments, or in other embodiments, LI is at least 0.025, 0.03, 0.04, or 0.05 times Lt. In some such embodiments, or in other embodiments, LI is no more than 0.45, 0.4, 0.3, 0.25, or 0.2 times Lt. In some such embodiments, or in other embodiments, L2 is at least 0.55, 0.6, 0.7, 0.75, or 0.8 times Lt. In some such embodiments, or in other embodiments, L2 is no more than 0.975, 0.97, 0.96, or 0.95 times Lt. For example, in some embodiments, for each structure 452a, the length LI of the first portion 413 of the second sidewall 412 is in a range of 0.04 to 0.3 times the total length Lt of the second sidewall 412 and the length L2 of the second portion 414 of the second sidewall 412 is in a range of 0.7 to 0.96 times the total length Lt of the second sidewall 412.

[0098] In some embodiments, the cushioning article further includes a plurality of second structures (e.g., 353a, 357a) disposed on the base layer of the cushioning article. In some embodiments, the plurality of second structures (e.g., 357a) is disposed on a same side of the base layer as the plurality of structures (e.g., 352a), and the plurality of structures and the plurality of second structures having different respective first and second average heights (e.g., hi and hi, respectively) from the base layer. In some embodiments, the plurality of structures and the plurality of second structures are disposed on opposite sides of the base layer (see, e.g., Figure 3C). In some embodiments, each second structure of the plurality of second structures includes opposing first and second sidewalls extending along the thickness direction of the cushioning article from the base layer to a curved top portion of the second structure, such that in the first cross-section, at least portions of each of the first and second sidewalls of the second structure are tilted toward a same second direction (minus x-direction) opposite the first direction (plus x- direction).

[0099] In some embodiments, a multilayer stack includes first and second films stacked on one another along a same thickness direction of the films, where each of the first and second films is or includes a cushioning article of the present description. In some embodiments, the films are oriented such that the structures of the films face opposite directions (see, e.g., Figure 3D). The first and second films can each be a cushioning article or film having structures including first and second sidewalls where at least portions of each of the first and second side walls are tilted toward a same first direction. In some embodiments, the first direction (e.g., +x-direction) of the first film is opposite the first direction (e.g., -x- direction) of the second film. In some embodiments, the multilayer stack further includes a substrate layer 359 disposed between the first and second films.

[0100] Figure 5A is a schematic cross-sectional view of the compression of a multilayer stack 550' of cushioning articles 550a and 550b, according to some embodiments. A multilayer stack 550' of cushioning articles or films can also be considered to be a cushioning article. Each of the cushioning articles 500a and 500b can correspond to cushioning article 350 or 450. A cover layer 573 is included in the multilayer stack 550' over the cushioning articles 550a and 550b. A sequence of increasing compression is represented by the arrows in the figure. In some embodiments, when a cushioning article is compressed along a thickness direction of the cushioning article, a tilt of the structures along the first direction increases. In some embodiments, when the cushioning article is further compressed along the thickness direction of the cushioning article, the structures curve while further tilting along the first direction so that the curved structures are concave toward the base layer.

[0101] Figure 5B is a schematic illustration of a compression force deflection curve (CFD; also referred to as a stress-strain curve), according to some embodiments. The stress-stain curves for a single layer of the corresponding cushioning article 350 (or 450, or 550a, for example) may appear substantially the same as that of the multilayer stack, but a single cushioning article provides less deflection distance than a multilayer stack of the cushioning articles. The structures of the exemplary cushioning article were arranged at a large pitch which can be reduced to increase the overall scale of the stress in the stressstrain curved. The stress scale may be further increased by using higher modulus materials for the structures 452a, for example, and / or increasing the width W of the structures 452a, for example. In some embodiments, a plot of compressive stress on the cushioning article when the cushioning article is compressed along the thickness direction of the cushioning article versus percent compression of the cushioning article includes a first portion 501 of the plot extending at least from 15 percent compression to 35 percent compression, where a largest compressive stress in the first portion 501 is no greater than 2 (or in a range described elsewhere herein) times a smallest compressive stress in the first portion 501. In some embodiments, the smallest compressive stress in the first portion is at least 100 kPa.

[0102] In some embodiments, a cushioning article 450 includes a plurality of structures 452a disposed on a base layer 420 of the cushioning article 450, where the structures 452a are arranged along a width of the cushioning article 450 and extend along a length of the cushioning article 450. The structures have an average height H from the base layer 420 to a top 428 of the structures 110 and are arranged at an average pitch P along a first direction (x-direction) along the width of the cushioning article 450. An average of a maximum width W of the structures along the first direction is W. In some embodiments, 7 H > P > H / 2 and 4 > H / W > 1. P / H and / or H / W can alternatively be an any of the respective ranges described elsewhere herein. In some embodiments, in a first cross-section orthogonal to the length of the cushioning article 450 and / or parallel to the width of the cushioning article 450, the structures 452a include a curved top portion 425 concave toward the base layer 420 and are tilted toward the first direction (e.g., the structures 452a can tilt in the +x-direction so that a center or centroid of the curved top portion 425 is at a larger x-value than an x-value of a center or centroid of a base of the structure 452a along the base layer 420 as schematically illustrated in FIG. 4a, for example) such that when the cushioning article is compressed along a thickness direction (z-direction) of the cushioning article 450, the structures 452 further tilt along the first direction (e.g., as schematically illustrated in Figure 5 A for the structures on cushioning layers 550a and 550b).

[0103] When the cushioning article is compressed along the thickness direction of the cushioning article, a plot of compressive stress versus percent compression can be generated. In some embodiments, a plot (see, e.g., Figure 5B) of compressive stress on the cushioning article 450 versus percent compression of the cushioning article 450 includes a first portion 501 extending at least from 15 percent compression to 35 percent compression, where a largest compressive stress in the first portion 501 is no greater than 2 times a smallest compressive stress in the first portion 501. In some such embodiments, or in other embodiments, the first portion 501 extends (e.g., starts from) at least from 14, 13, 12, 11, or 10 percent compression. In some such embodiments, or in other embodiments, the first portion 501 extends at least to 40, 45, 50, 60, 70, 80 percent compression. In some such embodiments, or in other embodiments, the largest compressive stress in the first portion 501 is no greater than 1.9, 1.8, 1.7, 1.6, or 1.5 times the smallest compressive stress in the first portion 501. In some such embodiments, or in other embodiments, the smallest compressive stress in the first portion 401 is at least 10, 20, 30, 50, 75, 100, 150, 200, 250, 300, 350 or 400 kPa. For example, in some embodiments, the first portion 501 extends at least from 12 percent compression to 50 percent compression, the largest compressive stress in the first portion 501 is no greater than 1.6 times the smallest compressive stress in the first portion 501, and the smallest compressive stress in the first portion 501 is in a range of 10 kPa to 400 kPa. The compressive stress versus percent compression can be determined, for example, according to the ASTM D3574-17 test standard.

[0104] In some embodiments, when the cushioning article is further compressed along the thickness direction of the cushioning article, the structures curve while further tilting along the first direction so that the curved structures are concave toward the base layer (see, e.g., Figure 5A).

[0105] In some embodiments, after the cushioning article is compressed a first time (1stcycle as shown in Figure 5B) with a compressive force along the thickness direction to at least 35, 40, 45, 50, 60, 70, 80 percent compression and then the compressive force is removed, when the cushioning article is then compressed a second time along the thickness direction, a second plot (2ndcycle as shown in Figure 5B) of compressive stress on the cushioning article versus percent compression of the cushioning article includes a second portion 502 extending at least from 15 percent compression to 35 percent compression, where a largest compressive stress in the second portion 502 is no greater than 2 times a smallest compressive stress in the second portion. In some such embodiments, or in other embodiments, the second portion 502 extends (e.g., starts from) at least from 14, 13, 12, 11, or 10 percent compression. In some such embodiments, or in other embodiments, the second portion 502 extends at least to 40, 45, 50, 60, 70, 80 percent compression. In some such embodiments, or in other embodiments, the largest compressive stress in the second portion 502 is no greater than 1.9, 1.8, 1.7, 1.6, or 1.5 times the smallest compressive stress in the second portion 502. In some such embodiments, or in other embodiments, the smallest compressive stress in the second portion is at least 10, 20, 30, 50, 75, 100, 150, 200, 250, 300, 350 or 400 kPa. For example, in some embodiments, the second portion 502 extends at least from 14 percent compression to 45 percent compression, the largest compressive stress in the second portion 502 is no greater than 1.7 times the smallest compressive stress in the second portion 502, and the smallest compressive stress in the second portion 502 is in a range of 10 kPa to 400 kPa.

[0106] Figure 6A is a schematic illustrative top-down view of an exemplary battery assembly module with the structured cushioning articles similar to that shown in Figure 3A, for example, according to some embodiments. The battery module 600 includes a plurality of battery cells 660 separated from each other by a gap, and a plurality of cushioning articles 650, with each cushioning article positioned in a gap between the battery cells 660. A base plate upon which the battery is typically positioned with thermally conductive gap fdler is not shown. In some embodiments, each cushioning article 650 has opposing structured and nominally planar surfaces as described for Figure 3A, for example, where the tips (top portions) of the structures of the structured surface contact one battery cell 660 and the nominally planar surface of the cushioning layer contact an adjacent cell.

[0107] Figure 6B is a schematic illustrative top-down view of an exemplary battery assembly module with the structured cushioning articles similar to that shown in Figure 3C, for example, according to some embodiments. The battery module 600 includes a plurality of battery cells 660 separated from each other by a gap, and cushioning articles 650 positioned in each of the gaps between adjacent battery cells 660. A base plate upon which the battery is typically positioned with thermally conductive gap fdler is not shown. Each cushioning article can include a predominantly solid silicone cushioning layer 650 having surface structure on each of two major opposing surfaces of the cushioning layer as described for Figure 3C, for example, where the tips of the structures of the two structured surfaces contact adjacent battery cells 660.

[0108] Figure 6C is a schematic illustrative top-down view of an exemplary battery assembly module with structured cushioning articles similar to that shown in Figure 3E, for example, according to some embodiments. The battery module 600 includes a plurality of battery cells 660 separated from each other by a gap, and cushioning articles 650 positioned in each gap between adjacent battery cells 660. A base plate upon which the battery is typically positioned with thermally conductive gap fdler is not shown. In some embodiments, each cushioning article 650 includes a predominantly solid silicone cushioning layer having a structured major surface and an opposite nominally planar major surface as described for Figure 3E, for example, where the tips of the structures of the structured major surface contact one battery cell 660 and the nominally planar surface of the cushioning layer contacts an adjacent cell.

[0109] As schematically illustrated in Figures. 6A-6C, for example, the structured surface(s) of the cushioning article 650 in contact with the battery cell 660 define airgaps 690 between the battery cell 660 and cushioning layer 650. These air gaps serve to reduce the effective thermal conductivity of the cushioning layer. Additionally, these defined air gaps created a directional channel for gasses to be vented preferentially away from the battery cell surfaces in the event of thermal runaway event and may also be used for fluid (e.g., air) cooling of the battery cells. In many embodiments, the surface structures of the cushioning layer 650 (and / or of the cushioning layers 750a, 750b, 750c, and / or 75 Od described elsewhere herein) are a compressible (e.g., due primarily to shape as described for Figure 5 A, for example, rather than bulk compressibility as an intrinsic property of the material) predominantly solid silicone structure and modify the force or stress exerted on the battery cell relative to the same solid silicone material having two flat major surfaces with both flat surfaces are in full contact with the adjacent cell surfaces.

[0110] Figure 6D is a schematic illustrative top-down view of an exemplary battery assembly module with structured cushioning article(s), according to some embodiments. In the embodiment of Figure 6D, the battery assembly 600 includes cylindrical battery cells 1060 with a cushioning article 650 extending non-linearly (e.g., weaving in and out) between battery cells. Cushioning article 650 of Figure 6D can schematically represent any cushioning article or film, or any stacks of cushioning articles or films, of the present description. For example, though not expressly shown in FIG. 6D, at least one of the opposing major surfaces of cushioning article 650 can include fin-shaped structures, for example, as described further elsewhere herein.

[0111] Figures 7A-7B are schematic illustrative top-down views of exemplary battery assembly modules 700 with structured cushioning layers 750a and 750b, where the structure of each cushioning layer is similar to that shown in Figure 3 A, for example, according to some embodiments. The battery module 700 includes a plurality of battery cells 760 separated from each other by a gap, and a multilayer cushioning article that includes cushioning layers 750a and 750b positioned in each gap between adjacent battery cells 760. In Figure 7A, the structures of cushioning layers 750a and 750b extend generally in a same direction while in Figure 7B, the structures extend in orthogonal directions (e.g., cushioning layer 750b is rotated by 90 degrees). While shown with the structured surfaces oriented in the same direction, cushioning layers 750a and 750b could alternatively be oriented with their planar sides in contact with one another and the structured surfaces of 750a and 750b in contact with adjacent battery cells 760. A base plate upon which the battery is typically positioned with thermally conductive gap filler is not shown. In the illustrated embodiments, the tips of the structures of cushioning layer 750a contact adjacent battery cells 760 and the tips of the structures on the structured surface of cushioning layer 750b contact the non-structured side of cushioning layer 750a. The structured sides of the cushioning layers 750a and 750b in contact with the flat surface of the battery cell 760 and planar side of cushioning layer 750a respectively define airgaps 790a and 790b. These airgaps may function as described elsewhere herein for other airgaps.

[0112] Figure 7C is a schematic cross-sectional view an exemplary battery assembly module 700 with multiple structured cushioning layers 750a, 750b, 750c, 750d and 750e where the structure of the cushioning layers can be similar to that shown in Figure 3a, for example, according to some embodiments. The battery module 700 includes a plurality of battery cells 760 separated from each other by a gap, and a multilayer cushioning article including cushioning layers 750a, 750b, 750c, 750d and 75 Oe positioned in the gap between adjacent battery cells 760. A base plate upon which the battery is typically positioned with thermally conductive gap filler is not shown. Figure 7C shows a battery assembly module wherein the cushioning articles 750a through 750e can comprise predominantly solid silicone cushioning layers having surface structure on one of the two major surfaces of the cushioning layer as described in Figure 3A, for example, where the tips of the structures of cushioning layer 750a contact an adjacent battery cells 760 and the tips of the structures on the structured surface of cushioning layer 750b, 750c, 75 Od and 75 Oe contact the non-structured side of cushioning layers 750a, 750b, 750c, and 750d respectively. The structured sides of the cushioning layers 750a through 750e in contact with the flat surface of the adjacent layers, define airgaps, 790a and 790b which may function as described elsewhere herein.

[0113] In some embodiments, it may be beneficial to have the structured surfaces of the multilayer cushioning stack aligned. While shown with the structured surfaces oriented in the same direction (aligned), cushioning layers 750a through 750e could be oriented such that the direction of the structures of each layer may be at some non-parallel angle with respect to another, for example alternating layers might have structures running in orthogonal directions. Additionally, while the cushioning layers are shown with their structured sides all facing in one direction, the cushioning layers could alternatively have their structured sides facing away from one another and their planar sides in contact with one another. In some embodiments, the structured surfaces of the cushioning layers on the outer sides of the multiple layer cushioning stack are oriented such that their structured surfaces are in contact with each side of the battery cells 760. Also, while each layer of the cushioning layer stack is schematically illustrated to have a same geometry, in some embodiments, some layers may have different structure shapes, sizes and / or length scale differences of the structure spacings, as it has been found that this can be advantageous in order to be able to tune the mechanical response of the multilayer cushioning stack, for example. In some embodiments, the flat / planar side of each cushioning layer may have a matte surface as described elsewhere. In some cases, some or all of the layers may also include two-sided cushion layers where both sides of the cushioning layer may be structured such as those shown in Figures 3C and 3D, for example.

[0114] In some embodiments, a multilayer stack includes a plurality of films stacked on one another along a same thickness direction of the films, where each film of the plurality of films is a cushioning article according to the present description. In some embodiments, the films are oriented such that the structures of the films face a same direction. In other embodiments, the structures of some of the films face one direction and the structures of others of the films face an opposite direction. In some embodiments, an assembly includes first and second electrochemical cells (e.g., any pair of adjacent battery cells of Figures 6A through 7C) and the multilayer stack disposed therebetween. A multilayer stack may alternatively, or in addition, be disposed between a battery cell (electrochemical cell) and a structural element of a battery assembly, such as a wall of a housing of the battery. Figure 7D is a schematic cross-sectional view of an assembly 700 including an electrochemical cell 760, a structural element 280, and a multilayer stack 790 disposed therebetween.

[0115] EXAMPLES

[0116] Materials:

[0117] Preparation of comparative example 1 (CE-1):

[0118] S38 XHS glass bubbles were compounded into ELKEM 3242 A and ELKEM 3242 B respectively through use of a DAC 600 SpeedMixer (FLACKTEK, Landrum, S.C.) at 2000 rpm for 1-2 minutes to provide a well-dispersed resin blend. Fillers were weighed into speedmix cups and wetted by the silicone fluid prior to mixing. S38 XHS glass bubbles were combined at 7.5 wt% to ELKEM 3242 A and 15.0 wt% to ELKEM 3242 B, with the remainder being ELKEM 3242 A or ELKEM 3242 B, respectively, to form the compounded precursors A and B. These compounded precursors were combined at a A:B weight ratio of 2: 1 and then mixed at 1200 rpm for 0.5 minutes. This mixture was then coated with a knife coater between two non-silicone non-fluorinated (NSNF) liners. The gap between the top and bottom was fixed at approximately 10 mil. The coating between the liners was then cured in a convective air oven at 90°C for 15 minutes. The resulting foam sheet was approximately 8 inches wide by about 10 inches in length with a thickness of 1.4 mm. Density, thermal conductivity and compression force deflection data were measured and are shown in Table 1A and Table IB. Preparation of comparative example 2 (CE-2):

[0119] Into a size 100 speed mixer cup was added 90.50 g of DOWSIL 93-104 Part A and 9.00 g of DOWSIL 93-104 Part B (~ 10: 1) ratio by weight). The resin was mixed in a DAC 150FZ SpeedMixer (FLACKTEK, Landrum, S.C) at 3000 rpm for 60 seconds for two cycles. A film sample was made from this mixture by pulling a hand spread using a notch bar coater where the sample was coated between two layers of 5 mil polyethylene terephthalate (PET) with the coating gap set to an approximately 40 mil thickness. The coating between the PET films was then cured in a convective air oven at 90°C for 2 hours. The resulting foam sheet was approximately 9-10 inches wide by about 9-10 inches in length with a thickness of 1.29 mm. Density, thermal conductivity and compression force deflection data were measured and are shown in Table 1A and Table IB.

[0120] Table 1A: Thermal Conductivity

[0121] Table IB: Stress from 3rd loading cycle of compression force deflection (kPa)

[0122] Torch Testing:

[0123] Torch testing of comparative example CE-1 and CE-2 were done to provide a comparison of thermal stability under a high temperature torch test to compare the properties of a silicone foam (CE-1) and predominantly silicone solid ablative material (CE-2). A 6 inch x 6 inch piece of each sample was mounted on a 0.46 stainless steel backplate and exposed to a hydrogen-oxygen torch at a distance of 1.0 inches and a target flame temperature of 1200C. The sample was exposed to the flame for 5 minutes or until the flame penetrated the sample and contacted the backplate. The results of the test are shown in Figure 8A for sample CE-1 and in Figure 8B for sample CE-2.

[0124] Sample CE-1, silicone foam, survived approximately 10 seconds before the torch breached the sample. The sample was severely damaged, with a significant portion of the foam combusting, as showed from the picture of the sample after the test in Figure 8A.

[0125] Sample CE-2, silicone ablative material, survived the torch exposure for 5 minutes with no breakthrough of the sample. The remnants of the test sample are shown in Figure 8B. As can be seen, the solid silicone ablative resin has significantly more durability than a silicone foam under extreme heat testing that might be experienced in a runaway event.

[0126] Preparation of structured predominantly solid silicone Sample Examples 1-5:

[0127] Examples 1-5 were made using tooling made to the structure description shown in Figure 9. The parameters indicated in this figure that were used in the Examples were Da = 421.05 micrometers (um), Db = 128.75 um, De = 126.66 um, Dd (radius of curvature) = 142.41 um, De = 475.00 um, Df = 425.20 um, Dg = 97.42 um, Dh (distance from bottom left comer to the end of radiused region along the top) = 224.07 um, Aa = 3.00 degrees, and Ab = 71.58 degrees. The tooling structures were arranged at a pitch of 1.1811 mm. The tooling was made by cutting a structure into a copper tool using a precision diamond cutting process. The resulting copper tools was plated with chrome and were treated with a hydrophobic release treatment. Theoretical calculations for the structured silicone ablative material are shown in Table 2 and the expected decrease in thermal conductivity versus the non-structured control CE-2 was approximated using one dimensional heat conduction calculations.

[0128] Table 2: Theoretical thermal conductivity calculations for Examples 1-5

[0129] Preparation of Example 1:

[0130] Into a size 100 speed mixer cup was added 90.01 g of DOWSIL 93-104 Part A and 9.02 g of DOWSIL 93-104 Part B (~ 10: 1) ratio by weight). The resin was mixed in a DAC 150FZ SpeedMixer (FLACKTEK, Landrum, S.C.) at 3000 rpm for 60 seconds for two cycles. A film sample was made from this mixture by coating the sample between a 2 mil thick PET film (Loparex 7300A) on a steel backup roll and the heated structured tool having structures as shown in Figure 9. The gap between the PET film and the structured tool was set to an approximately 55.5 mil thickness. Once the resin was on the tool and between the PET film and the heated tool, the line was stopped and the resin was allowed to cure for 10 minutes. After 10 minutes the cured structured silicone on the PET film was removed from the structured tool. The resulting silicone sheet was approximately 5-6 inches wide by about 9-10 inches in length and gave a single side replicated silicone film. A cross-sectional image of the single side structured silicone film including the PET film is shown in Figure 10A. The scale bar in the image is 400 microns. The ratio of the structure height, hi / hi was 0.29. The PET film was removed from the structured silicone and thickness, density and thermal conductivity were measured and the data for Example 1 is shown in Table 3.

[0131] Preparation of Example 2:

[0132] Into a size 100 speed mixer cup was added 44.99 g of DOWSIL 93-104 Part A and 4.51 g of DOWSIL 93-104 Part B (~ 10: 1) ratio by weight). The resin was mixed in a DAC 150FZ SpeedMixer (FLACKTEK, Landrum, S.C.) at 3000 rpm for 60 seconds for two cycles. A film sample was made from this mixture by coating the sample between a 2 mil thick PET film (Mitsubishi M64k7) on a steel backup roll and the heated structured tool having structures as shown in Figure 9. The gap between the PET film and the structured tool was set to an approximately 40.3 mil thickness. Once the resin was on the tool and between the PET film and the heated tool, the line was stopped and the resin was allowed to cure for 10 minutes. After 10 minutes the cured structured silicone bonded to the PET film was removed from the structured tool. The resulting silicone sheet was approximately 5-6 inches wide by about 9-10 inches in length and gave a single side replicated silicone film. A cross-sectional image of the single side structured silicone is shown in Figure 10B. The scale bar in the image is 400 microns. The ratio of the structure height, hi / hi was 0.42. Thickness, density and thermal conductivity data for the Example 2 is shown in Table 3.

[0133] Preparation of Example 3:

[0134] Into a size 100 speed mixer cup was added 45.02 g of DOWSIL 93-104 Part A and 4.51 g of DOWSIL 93-104 Part B (~ 10: 1) ratio by weight). The resin was mixed in a DAC 150FZ SpeedMixer (FLACKTEK, Landrum, S.C.) at 3000 rpm for 60 seconds for two cycles. A film sample was made from this mixture by coating the sample between a 2 mil thick PET film (Loparex 7300A) on a steel backup roll and the heated structured tool having structures as shown in Figure 9. The gap between the PET film and the structured tool was set to an approximately 26.8 mil thickness. Once the resin was on the tool and between the PET film and the heated tool, the line was stopped and the resin was allowed to cure for 10 minutes. After 10 minutes the cured structured silicone bonded to the PET film was removed from the structured tool. The resulting silicone sheet was approximately 5-6 inches wide by about 9-10 inches in length and gave a single side replicated silicone film. A cross-sectional image of the single side structured silicone film including the PET film is shown in Figure 10C. The scale bar in the image is 400 microns. The ratio of the structure height, hi / hi was 0.60. The PET film was removed from the structured silicone and thickness, density and thermal conductivity were measured and the data for Example 3 is shown in Table 3. Preparation of Example 4:

[0135] Into a size 100 speed mixer cup was added 45.03 g of DOWSIL 93-104 Part A and 4.57 g of DOWSIL 93-104 Part B (~ 10: 1) ratio by weight). The resin was mixed in a DAC 150FZ SpeedMixer (FLACKTEK, Landrum, S.C.) at 3000 rpm for 60 seconds for two cycles. A fdm sample was made from this mixture by coating the sample between a 2 mil thick PET fdm (Mitsubishi M64k7) on a steel backup roll and the heated structured tool having structures as shown in Figure 9. The gap between the PET fdm and the structured tool was set to an approximately 16.6 mil thickness. Once the resin was on the tool and between the PET fdm and the heated tool, the line was stopped and the resin was allowed to cure for 10 minutes. After 10 minutes the cured structured silicone bonded to the PET film was removed from the structured tool. The resulting silicone sheet was approximately 5-6 inches wide by about 9-10 inches in length and gave a single side replicated silicone film. A cross-sectional image of the single side structured silicone film including the PET film is shown in Figure 10D. The scale bar in the image is 400 microns. The ratio of the structure height, hi / hi was 0.71. The PET film was removed from the structured silicone and thickness, density and thermal conductivity were measured and the data for Example 4 is shown in Table 3.

[0136] Preparation of Example 5:

[0137] Into a size 100 speed mixer cup was added 36.63 g of DOWSIL 93-104 Part A and 3.65 g of DOWSIL 93-104 Part B (~ 10: 1) ratio by weight). The resin was mixed in a DAC 150FZ SpeedMixer (FLACKTEK, Landrum, S.C.) at 3000 rpm for 60 seconds for two cycles. A film sample was made from this mixture by coating the sample between a 2 mil thick PET film (Mitsubishi M64k7) on a steel backup roll and the heated structured tool having structures as shown in Figure 9. The gap between the PET film and the structured tool was set to an approximately 12.4 mil thickness. Once the resin was on the tool and between the PET film and the heated tool, the line was stopped and the resin was allowed to cure for 10 minutes. After 10 minutes the cured structured silicone bonded to the PET film was removed from the structured tool. The resulting silicone sheet was approximately 5-6 inches wide by about 9-10 inches in length and gave a single side replicated silicone film. A cross-sectional image of the single side structured silicone film including the PET film is shown in Figure 10D. The scale bar in the image is 400 microns. The ratio of the structure height, hi / hi was 0.82. The PET film was removed from the structured silicone and thickness, density and thermal conductivity were measured and the data for Example 5 is shown in Table 3.

[0138] The data in Table in Table 3 show that structuring the ablative silicone reduces the effective density of the ablative samples and that the thermal conductivity of the samples is reduced relative to the comparative example 2 (CE-2) which has no structure. Tuning of the structure shape, size and density at a surface is an important factor in the design of the cushioning layers to achieve the desired thermal performance as well as the mechanical performance. Table 3 : Data for Examples 1 -5

[0139] Compression force deflection curves for Examples 1-5 and Comparative example 2 (CE-2) are shown in the graph of Figure 11. It can clearly be seen that structuring of the predominantly solid thermally ablative material can have a dramatic softening effect on the compression force deflection mechanical response for the same material composition and that control of the stress strain can be modified significantly and that the structure to land ratio can have a distinct effect on extending the plateau region of the CFD curves.

[0140] To demonstrate the ability to hit a range of densities and thermal conductivities, Examples 6 - 16 show theoretical calculations for various structure to land thicknesses based on the structure geometries shown in Figures 12A and 12B where the dimensions used in the Examples were Dj = 675 micrometers, Dk = 250.02 micrometers, Ac = 14.00 degrees, Ad = 8.95 degrees, Ae = 1.59 degrees, and Af = 14.07 degrees. The length DI used in the Examples was 750 micrometers in FIG. 12A and 1000 micrometers in FIG. 12B. It will be appreciated that modification of structure shape, size, pitch, and film design (single sided versus two sided) can allow for fine tuning of thermal properties. Results are provided in Tables 4A-4B.

[0141] Table 4A: Thermal conductivity calculations for Examples 6 - 10, percent improvement vs. Control CE 2 for equivalent thickness

[0142] Table 4B: Thermal conductivity calculations for Examples 11 - 16, percent improvement vs. Control CE

[0143] 2 for equivalent thickness

[0144] Test Methods:

[0145] Thermal conductivity of the structured silicone fdms was measured with a TA Instruments Fox 50 Heat Flow Meter. Circular discs, 2 inches in diameter were punched out of each foam sample. The top platen temperature was set to 70°C and the bottom platen was set to 50°C. A platen pressure of 300 kPa was applied to compress the foam between the platens. Once the top and bottom platens reach temperature setpoint, the platen displacement and thermal flux are measured repeatedly until reaching equilibrium. A thermal conductivity is reported at equilibrium based on the sample dimensions.

[0146] Compression force deflection (CFD) measurements were measured on the comparative examples and examples using the following method. Circular diameter discs, 50.8 mm in diameter were punched out of each sample. Samples were loaded between parallel platens in an Instron Model 5581 with a 5kN load cell. Test followed a modified ASTM D3574-17 with a modified preload of 725 Pa. Compressive load was recorded for three consecutive compressions from 0-90% strain with a constant displacement of 1 mm / minute for all strains from OkPa to 1800kPa. The 3rd cycle was used for evaluation and reported in Figure 11 and tabulated in Table IB for each of the samples.

[0147] Density measurements were done on die punched 45.1 mm diameter specimens. Mass in grams was measured with a scale. Thickness was measured with a digital thickness gauge using a 28 mm diameter pressure foot and an applied mass of 10 g. Density in grams per cubic centimeter was calculated by dividing the specimen mass by the volume.

[0148] Terms such as “about” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “about” as applied to quantities expressing feature sizes, amounts, and physical properties is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “about” will be understood to mean within 10 percent of the specified value. A quantity given as about a specified value can be precisely the specified value. For example, if it is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, a quantity having a value of about 1, means that the quantity has a value between 0.9 and 1.1, and that the value could be 1.

[0149] Terms such as “substantially” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “substantially” with reference to a property or characteristic is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description and when it would be clear to one of ordinary skill in the art what is meant by an opposite of that property or characteristic, the term “substantially” will be understood to mean that the property or characteristic is exhibited to a greater extent than the opposite of that property or characteristic is exhibited.

[0150] All references, patents, and patent applications referenced in the foregoing are hereby incorporated herein by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description shall control.

[0151] Descriptions for elements in figures should be understood to apply equally to corresponding elements in other figures, unless indicated otherwise. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and / or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations, or variations, or combinations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.

Claims

What is claimed is:

1. A cushioning article comprising a plurality of structures disposed on a base layer of the cushioning article, the structures being arranged along a width of the cushioning article and extending along a length of the cushioning article, each structure comprising opposing first and second sidewalls extending along a thickness direction of the cushioning article from the base layer to a curved top portion of the structure, such that in a first cross-section orthogonal to the length of the cushioning article and for each structure of the plurality of structures, the curved top portion is concave toward the base layer and at least portions of each of the first and second sidewalls are tilted toward a same first direction along the width of the cushioning article, wherein the structures comprise a solid material at no less than 60 volume percent based on a total volume of the structures, the solid material comprising a cross-linked silicone elastomer and solid filler dispersed therein.

2. The cushioning article of claim 1, wherein the structures comprise hollow particles dispersed in the cross-linked silicone elastomer.

3. The cushioning article of claim 1, wherein the structures comprise air entrapped in the in the crosslinked silicone elastomer at no more than 15 volume percent based on the total volume of the structures.

4. The cushioning article of claim 1, wherein the solid material comprises the solid filler at no less than 10 volume percent based a total volume of the solid material.

5. The cushioning article of claim 1, wherein for each structure of the plurality of structures: the first and second sidewalls make respective first and second angles with the same first direction along the width of the cushioning article, the first angle being greater than 40 degrees and less than 90 degrees along substantially an entire length of the first sidewall, the second angle being in a range of 90 to 150 degrees along substantially an entire length of a first portion of the second sidewall and being in a range of 70 to 89.5 degrees along substantially an entire length of a second portion of the second sidewall, the first portion disposed between the base layer and the second portion, the second portion disposed between the first portion and the curved top portion, the length of the second portion greater than the length of the first portion.

6. The cushioning article of claim 5, wherein for each structure of the plurality of structures, the length of the second portion of the second sidewall is at least 2 times the length of the first portion of the second sidewall.

7. The cushioning article of claim 6. wherein for each structure of the plurality of structures, a total length of the first and second portions of the second sidewall is at least 80% of a total length of the second sidewall.

8. The cushioning article of claim 5, wherein for each structure of the plurality of structures, the second angle changes between the first and second portions of the second sidewall to define a hinge region, the first portion of the second sidewall extending from the base layer to the hinge region and the second portion of the second sidewall extending from the hinge region to the curved top portion.

9. A cushioning article comprising a plurality of structures disposed on a base layer of the cushioning article, the structures being arranged along a width of the cushioning article and extending along a length of the cushioning article, each structure comprising opposing first and second sidewalls extending along a thickness direction of the cushioning article from the base layer to a curved top portion of the structure, such that in a first cross-section orthogonal to the length of the cushioning article and for each structure of the plurality of structures, the curved top portion is concave toward the base layer and at least portions of each of the first and second sidewalls are tilted toward a same first direction along the width of the cushioning article, wherein the structures comprise a cross-linked silicone elastomer and filler dispersed therein, the filler comprising solid filler material and hollow particles.

10. The cushioning article of claim 9, wherein the structures comprise no less than 40 volume percent solid material based on a total volume of the structures.

11. The cushioning article of claim 9, wherein the structures comprise the filler at no less than 10 volume percent based a total volume of the structures.

12. The cushioning article of claim 9, wherein the structures comprise the solid filler material at no less than 10 volume percent based a total volume of the structures.

13. The cushioning article of claim 9, wherein the structures comprise the hollow particles at no less than 10 volume percent based a total volume of the structures.

14. The cushioning article of claim 9, wherein the structures comprise each of the solid filler material and the hollow particles at no less than 10 volume percent based on a total volume of the structures, and comprise the solid filler material and the hollow particles at no more than 55 volume percent in total based on the total volume of the structures.

15. The cushioning article of claim 9, wherein for each structure of the plurality of structures:the first and second sidewalls make respective first and second angles with the same first direction along the width of the cushioning article, the first angle being greater than 40 degrees and less than 90 degrees along substantially an entire length of the first sidewall, the second angle being in a range of 90 to 150 degrees along substantially an entire length of a first portion of the second sidewall and being in a range of 70 to 89.5 degrees along substantially an entire length of a second portion of the second sidewall, the first portion disposed between the base layer and the second portion, the second portion disposed between the first portion and the curved top portion, the length of the second portion greater than the length of the first portion.

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