Article including structured paper, battery module including the article, and related processes

Abstract

An article includes a first sheet of a first non-cellulosic paper having a first major surface and an opposing second major surface and a structured paper including non-cellulosic fibers. The structured paper has ridges and troughs each having an outer surface with land areas, and the land areas of at least a portion of the ridges are joined to at least a portion of the first major surface of the first sheet. A battery module that includes a plurality of battery cells electrically connected to one another and the article is also described. Processes for making and using the article are also described.

Description

[0001] PA101411W002

[0002] ARTICLE INCLUDING STRUCTURED PAPER, BATTERY MODULE INCLUDING THE ARTICLE, AND RELATED PROCESSES

[0003] BACKGROUND

[0004] Large-scale batery packs used in automotive and stationary applications are traditionally arranged in arrays that allow for the connection of cells in series and parallel configuration using metallic inter-connections. The array of cells is then enclosed in a mechanical structure that is meant to protect the batery pack from external conditions.

[0005] During the operation of a batery pack, due to several reasons, a batery cell can go into thermal runaway. When a cell goes into thermal runaway, the internally generated hot gases and sometimes flames are rapidly ejected from the cell. To control the direction of ejection, manufacturers typically incorporate a vent or weakened area of the cell that preferentially ruptures. When the cell ruptures, hot gases, flames, and conductive metal particles can be shot out into the main array area.

[0006] After escaping the cell, the gases and particles can cause significant damage to the surrounding cells. Forms of damage include the transference of the heat, burning, and the creation of electrical shorts. The damage to surrounding cells can be significant enough to induce thermal runaway in adjacent cells, which results in thermal runaway propagation. The way that the damage is spread to adjacent cells can take many forms. For example, particles and gases ejected from the cells can deflect off the underside of the array enclosure and back to the surrounding cells.

[0007] U.S. Pat. Appl. Pub. No. 2024 / 0079719 (Zhang et al.) describes a batery module including a flame barrier sheet. In unrelated technologies, U.S. Pat. Appl. Pub. Nos. 2015-0118464 (Turpin et al.) and 2022-0379592 (Geerts et al.) and U.S. Pat. No. 6,443,257 (Wiker) describe various multi-layered articles including paper.

[0008] SUMMARY OF THE DISCLOSURE

[0009] In one aspect, the present disclosure provides an article including a first sheet of a first nonce llulosic paper having a first major surface and an opposing second major surface and a structured paper including non-cellulosic fibers. The structured paper has ridges and troughs each having an outer surface with land areas, and the land areas of at least a portion of the ridges are joined to at least a portion of the first major surface of the first sheet.

[0010] In another aspect the present disclosure provides a batery module that includes a plurality of batery cells electrically connected to one another and the article described herein.

[0011] In another aspect, the present disclosure provides a batery module including a lid, a plurality of batery cells electrically connected to one another, each of the plurality of batery cells including a vent, and the article described herein at least one of under the lid, above the vent of at least some of the plurality of battery cells, or between two of the plurality of battery cells.

[0012] The present disclosure further provides a vehicle that includes the battery module.

[0013] In another aspect, the present disclosure provides a process for making a structured paper. The process includes mounting first and second generally cylindrical structuring members in an axially parallel relationship, each of the first and second structuring members having an axis and including a plurality of spaced ridges defining the periphery of the structuring member, the ridges having outer surfaces and defining spaces between the ridges adapted to receive portions of the ridges of the other structuring member in a meshing relationship, rotating at least one of the structuring members, and feeding a sheet of paper including at least one of inorganic fibers or inorganic particles between the meshed portions of the ridges to generally conform the sheet of paper to the periphery of the first structuring member and form ridges in the structured paper in the spaces between the ridges of the first structuring member and troughs in the structured paper along the outer surfaces of the ridges of the first structuring member.

[0014] In another aspect, the present disclosure provides a process for making the article described herein. The process includes mounting first and second generally cylindrical structuring members in an axially parallel relationship, each of the first and second structuring members having an axis and including a plurality of spaced ridges defining the periphery of the structuring member, the ridges having outer surfaces and defining spaces between the ridges adapted to receive portions of the ridges of the other structuring member in a meshing relationship, rotating at least one of the structuring members, feeding a sheet of paper including non-cellulosic fibers between the meshed portions of the ridges to generally conform the sheet of paper to the periphery of the first structuring member and form the ridges in the structured paper in the spaces between the ridges of the first structuring member and the troughs in the structured paper along the outer surfaces of the ridges of the first structuring member, and joining the ridges of the structured paper to the first major surface of the first sheet of non-cellulosic paper.

[0015] The article of the present disclosure is suitable for use, for example, in battery modules. At least some embodiments of the present disclosure provide an article having a balance of properties including flame resistance, dimensions, thermal conductivity, and stiffness or compressive strength useful for battery modules. At least some embodiments of the present disclosure are able to achieve high flame resistance ratings even though they contain some flammable materials (e.g., adhesives).

[0016] BRIEF DESCRIPTION OF THE FIGURES

[0017] The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present disclosure.

[0018] FIG. la is a schematic section view of an embodiment of an article of the present disclosure.

[0019] FIG. lb is a schematic section view of another embodiment of an article of the present disclosure.

[0020] FIG. 2 is a schematic side view of an embodiment of the battery module of the present disclosure with an article of the present disclosure at least partially covering battery cells within the module. FIG. 3 is a schematic side view of another embodiment of the battery module of the present disclosure with articles of the present disclosure between at least some battery cells within the module.

[0021] FIG. 4 is a schematic representation of a method for making an embodiment of the article of the present disclosure.

[0022] DETAILED DESCRIPTION

[0023] Reference will now be made in detail to certain embodiments of the disclosed subject matter, examples of which are illustrated in part in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0024] Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

[0025] In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A or B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[0026] The term “comprises” and variations thereof do not have a limiting meaning where these terms appear in the description and claims. Such terms will be understood to imply the inclusion of a stated step or element or group of steps or elements but not the exclusion of any other step or element or group of steps or elements. By “consisting of’ is meant including, and limited to, whatever follows the phrase “consisting of.” Thus, the phrase “consisting of’ indicates that the listed elements are required or mandatory, and that no other elements may be present.

[0027] In the methods described herein, the acts can be carried out in any order without departing from the principles of the disclosure, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process. The term “non-cellulosic” means containing less than 10 weight percent (wt%) cellulosic material, containing less than 5 wt% cellulosic material, containing only trace amounts of cellulosic material, or, in some embodiments, containing no cellulosic material.

[0028] A fiber as defined herein has an aspect ratio of the longest dimension to any of its other dimensions of at least 3: 1, 4: 1, 5: 1, 10: 1, 25: 1, 50: 1, 75: 1, 100: 1, 150: 1, 200: 1, 300: 1, 400: 1, or more; or in a range from 3: 1 to 600: 1, 3: 1 to 550: 1, or 3: 1 to 500: 1. For fibers with a circular cross-section, the aspect ratio is defined as the length to the diameter of the cross-section. For fibers with two or more cross-sectional dimensions, the aspect ratio is defined as the length to the largest cross-sectional dimension. In some embodiments, fibers are less than one inch (2.54 cm) long.

[0029] As reported in Russell, S.J. Handbook of Nonwovens,' Woodhead Publishing: Cambridge, England, 2007; p. 2, the European Disposables and Nonwovens Association (EDANA), a paper is not included in the definition of nonwoven. Also, INDA, the Association of the Nonwovens Fabrics Industry, distinguishes paper from nonwovens in its glossary of terms. Further according to INDA, wetlaid nonwovens have more than 30% by mass of their fibrous content made up of fibers (excluding chemically digested vegetable fibers) with a length to diameter ratio greater than 600, and / or wetlaid nonwovens have a density of less than 0.4 grams per cubic centimeter (g / cc). In some embodiments, the paper described herein has greater than 70%, 80%, or 90% by weight of its fibrous content made up of fibers with a length to diameter ratio less than 600 and / or a density of greater than 0.4 g / cc.

[0030] Fiber length to diameter ratios can be measured according to TAPPI T 401 Fiber Analysis. Fiber length to diameter ratios can also be measured with microscopes or stereoscopes using calibrated oculars or rulers.

[0031] The term "crosslinked” refers to polymer chains joined together by covalent chemical bonds, usually via crosslinking molecules or groups, to form a network polymer. A crosslinked polymer is generally characterized by insolubility but may be swellable in the presence of an appropriate solvent.

[0032] The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range and includes the exact stated value or range.

[0033] Embodiments of the article of the present disclosure are illustrated in FIGS, la and lb. Articles 10a and 10b each include a first sheet 12 of non-cellulosic paper having first and second opposing major surfaces 11, 13. Structured paper 14a, 14b has ridges 22a, 22b and troughs 26a, 26b, each having an outer surface with land areas 28a, 28b. Structured paper 14a, 14b comprises non-cellulosic fibers. The land areas 28a, 28b of at least some of the ridges 22a, 22b are joined to at least a portion of the first major surface 11 of the first sheet 12. FIG. la illustrates a sinusoidal shaped structured paper for which the land areas 28a are curved. In the embodiment illustrated in FIG. lb, the structured paper 14b has a trapezoidal wave structure in which land areas 28b are generally flat. The shapes of the ridges and troughs are not limited and may also have a square wave or figure 8 structure. FIG. lb further includes a second sheet 16 of non-cellulosic paper joined to at least some of the land areas 28b of the troughs 26b. In some embodiments, the first sheet independently comprises non-cellulosic fibers. In some embodiments, the second sheet independently comprises non-cellulosic fibers. Examples of commercially available fibrous papers suitable for the first sheet, the second sheet, and the structured paper include those available from 3M Company, St. Paul, MN, USA, under the trade designations “CeQUIN”, including CeQUIN I (about 90% inorganic content), CeQUIN II (two-layer (ply) composites of CeQUIN I), CeQUIN X (enhanced wet strength for B-stage applications), and CeQUIN 3000 (about 74% inorganic content plus organic fiber reinforcement) and “FEAME BARRIER FRB” including FLAME BARRIER-FRB-NT calendered insulation paper and FLAME BARRIER FRB-NC noncalendered insulation paper; those available from DuPont, Wilmington, DE, USA, under the trade designation “NOMEX”, including NOMEX Paper Type 410, Type 411 (lower density version), Type 414, Type 418 (includes mica), Type 419 (lower density version of Type 418), and Type E56; those available from SRO Group (China) Co. Ltd., Shanghai, China, under the trade designation “X-FIPER”; and those available from Yantai Metastar Special Paper Co., Ltd., Yantai, China, under the trade designation “METASTAR”.

[0034] Papers suitable for the first sheet, the second sheet, and the structured paper include those having non-cellulosic fibers. The fibers in at least one of the first sheet, the second sheet, or the structured paper, may be inorganic, organic, or a combination thereof. In some embodiments, each paper including non- cellulosic fibers independently comprises inorganic fibers. In some embodiments, each paper including non-cellulosic fibers independently comprises organic fibers. Examples of suitable organic and inorganic fibers include aramid (e.g., meta-aramid and para-aramid), polyphenylene sulfide (PPS), polyester, polyamides, acrylic, melamine, glass, polyolefin, and polyimide. In some embodiments, the fibers in at least one of the first sheet, the second sheet, or the structured paper, are inorganic, aramid, or a combination thereof. In some embodiments, the fibrous paper also comprises a polymeric binder. Suitable polymeric binders include acrylic, nitrile, styrene acrylic latex, guar gum, starch, and natural rubber latex binders.

[0035] In some embodiments, the paper of at least one of the first sheet, the second sheet, or the structured paper independently comprises non-fibrous inorganic particles. Examples of suitable inorganic particles include kaolin clay, talc, mica, calcium carbonate, alumina trihydrate, montmorillonite, smectite, bentonite, illite, chlorite, sepiolite, attapulgite, halloysite, vermiculite, laponite, rectorite, perlite, aluminum nitride, silicon carbide, boron nitride, and combinations thereof. Suitable types of kaolin clay include water-washed kaolin clay; delaminated kaolin clay; calcined kaolin clay; and surface-treated kaolin clay. In some embodiments, at least one of the first sheet, the second sheet, or the structured paper independently comprises clay particles. In some embodiments, each non-cellulosic paper independently comprises clay particles.

[0036] In some embodiments, at least one of the first sheet, the second sheet, or the structured paper comprises at least one of inorganic fibers or inorganic particles. Papers useful for practicing the present disclosure containing at least one of inorganic fibers or inorganic particles may be referred to as inorganic-based papers or inorganic papers. Inorganic papers can provide greater dimensional stability as well as higher thermal conductivity for improved heat dissipation compared to, for example, completely organic based meta-aramid papers. The paper obtained under the trade designation “NOMEX 410” from DuPont is a flexible, 100% m-aramid paper and not an inorganic paper. In some embodiments, the structured paper is not completely organic and / or not a 100% by weight m-aramid paper. In some embodiments, none of the first sheet, the second sheet, or the structured paper is completely organic. In some embodiments, none of the first sheet, the second sheet, or the structured paper is a 100% m-aramid paper.

[0037] The first sheet and the second sheet, if present, may include non-cellulosic papers that are not fibrous. In some embodiments, at least one of the first sheet or the second sheet comprises mica. At least one of the first sheet or the second sheet can be a flexible mica paper. Useful mica papers can comprise mica and a glass scrim. Mica is not fibrous. In some embodiments, the structured paper does not comprise mica. In some embodiments, none of the first sheet, the second sheet, or the structured paper comprises mica.

[0038] In some embodiments, at least one of the first sheet, the second sheet, or the structured paper has a thickness of up to 0.40 mm, up to 0.30 mm, or up to 0.20 mm. In some embodiments, at least one of the first sheet, the second sheet, or the structured paper has a thickness of at least 0.05 mm, at least 0.075 mm, or at least 0.10 mm. In some embodiments, at least one of the first sheet, the second sheet, or the structured paper has a thickness of 0.1016 mm (0.004 inch) or 0.127 mm (0.005 inch). At least one of the first sheet, the second sheet, or the structured paper may be selected to have tensile properties that allow it to rupture during a fire as described above in connection with FIGS. 2 and 3.

[0039] A variety of processes may be useful for providing the structured paper. In some embodiments, including the embodiment illustrated in FIG. 4, the structured paper is prepared by providing first and second heated structuring members or rollers 46 and 47 each having an axis and including a plurality of circumferentially spaced generally axially extending ridges 43 around and defining its periphery, with the ridges 43 having outer surfaces and defining spaces 41 between the ridges 43 adapted to receive portions of the ridges 43 of the other structuring member 46 or 47 in meshing relationship with a sheet of paper 14 comprising non-cellulosic fibers, in some embodiments, comprising at least one of inorganic fibers or inorganic particles, between the meshed ridges 43. The structuring members 46 and 47 are mounted in axially parallel relationship with portions of the ridges 43 of the structuring members 46 and 47 meshing generally in the manner of gear teeth. At least one of the structuring members 46 or 47 is rotated, and the sheet of paper 14 is fed between the meshed portions of the ridges 43 of the structuring members 46 and 47 to generally conform the sheet of paper 14 to the periphery of the first structuring member 46 and form the ridges 22 of the sheet of paper 14b in the spaces 41 between the ridges 43 of the first structuring member 46 and the troughs 26 of the sheet of paper 14b along the outer surfaces of the ridges 43 on the first structuring member 46.

[0040] Structuring members 46 and 47 adapted to have such a sheet of paper 14 fed into them can have their ridges 43 oriented generally in the range of 0 to 45 degrees with respect to their axes, but in some embodiments have their ridges 43 oriented at 0 degrees with respect to (or parallel to) their axes which simplifies making of the structuring members 46 and 47. In some embodiments (not shown) each structuring member can have generally annular, circumferentially extending, axially spaced parallel elongate ridges around and defining its periphery, in other words, generally perpendicular to its axis. Further details about such structuring members may be found in U.S. Pat. Nos. 5,256,231 (Gorman et al.) and 7,303,805 (Seth et al.)

[0041] In some embodiments, the land areas of at least a portion of the ridges of the structured paper are joined to at least a portion of the first major surface of the first sheet with an adhesive. In some embodiments, the land areas of at least a portion of the troughs of the structured paper are joined to the second sheet with an adhesive, which may be the same or different from the adhesive joining at least a portion of the ridges to the first sheet. In some embodiments, each adhesive independently comprises at least one of a silicate adhesive or a silicone adhesive. In some embodiments, the structured paper and sheet(s) of non-cellulosic paper are bonded by calendering with only heat and pressure, and no adhesive is used.

[0042] Silicate adhesives typically comprise an alkali silicate. Suitable alkali silicates include cesium silicate, lithium silicate, a potassium silicate, a sodium silicate, and combinations thereof. In some embodiments, the alkali silicate comprises at least one of lithium silicate, sodium silicate, or potassium silicate. In some embodiments, the alkali silicate comprises sodium silicate. Alkali silicates can be obtained, for example, as aqueous solutions from commercial sources, for example, PQ Corporation, Malvern, PA, USA. Suitable lithium silicates can be obtained, for example, from PQ Corporation under the trade designations “UITHISIU 829” and “UITHISIU 25”. Further suitable alkali silicates are sodium silicates having a weight ratio of SiCUNajO in a range from 1.6 to 2.5 and potassium silicates with a weight ratio of SiCUIGO in a range from 1.6 to 2.5. Other suitable alkali silicates include sodium or ammonium stabilized silica sols such as those available from Nalco Company, Naperville, IU, USA. Useful concentrations in the silicate solutions include at least 40 % to 42 % by weight solids, and the weight ratio of silicon dioxide to lithium, sodium, or potassium oxide is typically in a range from 1 : 1 to 10: 1. In some embodiments, the alkali silicate has a molar ratio of silicon to alkali metal of not more than 3.22 to 1. Silicate adhesives are typically heated to eliminate water and cause condensation to form a three-dimensional polymeric =Si-O-Si= network. Temperatures in a range from 60 °C to 350 °C may be useful. Aluminum sulfate, sodium bicarbonate, monosodium phosphate, calcium chloride, magnesium sulfate, borax, sodium metaborate, zinc oxide, and / or sodium silicofluoride may be added to co-react with the alkali silicates. Extenders such as sodium chloride, clay, or talc may also be useful in the silicate adhesive composition.

[0043] A variety of silicone adhesives may be useful in the article of the present disclosure. A silicone adhesive can have, for example, (i) one or more reactive silicone polymers, (ii) optionally one or more fillers, (iii) a crosslinking agent, and (iv) a catalyst. The silicone adhesive can be heat vulcanizing (HTV) or room temperature vulcanizing (RTV). The silicone adhesive composition can be, for example, moisture-curing, free -radically curing, condensation curing, or addition curing. Moisture-curing silicone adhesives generally include a polysiloxane with hydroxyl end groups or hydrolyzable and condensable end groups, a crosslinking agent, and a polycondensation catalyst (e.g., a tin salt or an alkyl titanate). A free-radially curing silicone adhesive typically includes a polysiloxane having at least two alkenyl groups and a catalytic amount of a free-radical initiator such as an organic peroxide. A condensation-curing silicone adhesive can include a combination of a polysiloxane having amine groups and a polysiloxane having epoxy groups or a combination of a polysiloxane having amine or hydroxyl groups and a polysiloxane having isocyanate groups and an appropriate catalyst. An addition-curing silicone adhesive typically includes a polysiloxane having at least two alkenyl groups (e.g., vinyl groups) attached to silicon atoms in a molecule, a hydrosilyl-substituted polysiloxane having at least two silicon-hydride (i.e., Si-H), in some embodiments, at least three silicon-hydride groups in a molecule, and a catalytic amount of an addition reaction catalyst. The silicone adhesive may also include a polysiloxane having at least two alkenyl groups (e.g., vinyl groups) and a polysiloxane having at least two mercaptan groups and optionally a free-radical initiator. Useful silicone adhesives can be packaged as one-part or two-part compositions. An example of a useful two-part, addition-curing silicone adhesive can be obtained from Dow, Midland, MI, under the trade designation “SYLGARD 184”.

[0044] Other adhesives that may be useful in the article of the present disclosure include poly(vinyl acetate), poly(vinyl alcohol), starch, acrylic, styrene-acrylate, polyester, and ethylene vinyl chloride adhesives.

[0045] One or more flame retardants may be added to the adhesive, if desired. Examples of suitable flame retardants include phosphorous-containing flame retardants (e.g., phosphates, polyphosphates, phosphonates, phosphinates, phosphazenes, phosphines, phosphine oxides, and combinations thereof), nitrogen-containing polymers, aluminum trihydroxide (ATH), magnesium hydroxide (Mg(0H)2), wollastonite, boron-containing compounds, antimony oxide, expandable graphite, a humite / hydromagnesite blend, and combinations thereof. Other flame retardants may also be useful. The one or more flame retardants can be present in the adhesive in a range of from about 2 weight percent (wt%) to about 50 wt%, about 5 wt% to about 40 wt%, or about 5 wt% to about 25 wt%, based on the total weight of the adhesive.

[0046] Referring again to FIGS. 1A and IB, in some embodiments, including the embodiment illustrated in FIG. 1A, the adhesive 29a is applied discontinuously on the land areas 28a. In some embodiments, including the embodiment shown in FIG. IB, the adhesive 29b is applied continuously on at least one of first or second opposing structured major surfaces of the structured paper 14b. Applying the adhesive can be carried out by any desired technique such as spraying, brushing, roll coating, knife coating, curtain coating, or die coating.

[0047] Rolls of non-cellulosic paper disposed at least one of above or below the structured paper can be useful for feeding the first and optionally second sheet of non-cellulosic paper onto the adhesive-coated structured paper in a continuous manner. A series of air convection blowers can be used to apply heat to cure the adhesive, if desired, and / or the construction can be passed through an oven. A slitter may be useful for cutting the article to a desired size. The present disclosure provides a battery module that includes a plurality of battery cells electrically connected to one another and the article described herein in any of its embodiments. FIG. 2 is a side view of battery cells 201 in an embodiment of a battery module 200 of the present disclosure. The battery cells 201 are typically electrically connected to one another. In some embodiments, each battery cell includes a vent although this is not shown. The battery module 200 comprises an enclosure 203 having a lid 205 and walls. In the embodiment shown in FIG. 2, the article of the present disclosure 210 is under the lid 205 and, in some embodiments, above the vent of at least some of the plurality of battery cells 201. Certain battery cells (e.g., pouch cells) do not have vents.

[0048] FIG. 3 is a side view of battery cells 301 in another embodiment of a battery module 300 of the present disclosure in which the article of the present disclosure 310 is located between two of the plurality of battery cells 301. In the illustrated embodiment, an article of the present disclosure 310 is located between every two of the plurality of battery cells 301. In the illustrated embodiment, an article of the present disclosure is also located under the lid 305, for example, above the vent of at least some of the plurality of battery cells 301. In some embodiments, multiple articles of the present disclosure 210, 310 are located between at least some of the plurality of battery cells but not above the vent of at least some of the plurality of battery cells 201, 301.

[0049] Battery module 200, 300 can be a component of a vehicle, for example, an all-electric vehicle (EV), a plug-in hybrid vehicle (PHEV), or a hybrid vehicle (HEV). Examples of suitable vehicles include an automobile, a train, an aerospace vehicle (e.g., airplane, helicopter, or space craft), or a watercraft.

[0050] Suitable examples of battery modules of the present disclosure include lithium-ion batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel manganese cobalt (NMC) batteries. Lithium iron phosphate (LFP) is a useful cathode chemistry for lithium-ion batteries, having a relatively low energy density, suitable in the battery module of the present disclosure. In some embodiments, the battery module includes a Lithium Manganese Iron Phosphate (LMFP) cathode, a member of the LFP family.

[0051] For relatively low energy density battery modules, it is useful for them to be designed to have a smaller volume and relatively low density to improve the pack-level energy density. Advantageously, the article of the present disclosure can be made with a relatively low thickness, for example, for fitting under the lid and / or between the cells in a battery module. In some embodiments, the article has a thickness of not more than 10, 9, 8, 7, 6, 5, 4, 3, or 2 millimeters or not more than one millimeter. In some embodiments, the article of the present disclosure has a thickness of at least 0.5 millimeter. In some embodiments, the article of the present disclosure has a thickness in a range from 0.5 mm to 10 mm, from 0.5 mm to 5 mm, from 0.5 to 2.5 mm, from 0.5 to 2 mm, from 0.5 mm to 1.5 mm, or from 0.5 mm to 1 mm. Referring again to FIGS. 1A and IB, the thickness “T” of the article is measured from the second major surface 13 of the first sheet 12 to the land areas of the troughs in FIG. 1A and from the second major surface 13 of the first sheet 12 to the second major surface 17 of the second sheet 16 in FIG. IB. Advantageously, the structured paper in the article of the present disclosure helps to lower the density of the article by including air gaps 25 as shown in FIG. IB. If an individual batery cell 201 such as that illustrated in FIG. 2 catches on fire, the article of the present disclosure can rupture locally due to the resulting high-pressure blast, and gas from the fire can be released into channel 206. The article is desirably resistant to hot particles that may rain down during a thermal event. The article of the present disclosure can help reduce spread of flames from one batery cell to another in the event of a fire by keeping the flames in channel 206. In some embodiments, the article of the present disclosure meets a UL 94 standard of at least one of V2, VI, VO, or 5VA. In some embodiments, the article of the present disclosure meets a UL 94 standard of at least one of VO or 5VA. A low thermal conductivity is useful to provide a heat barrier. In some embodiments, the article of the present disclosure has a thermal conductivity of not more than 0.3 wat per meter-kelvin (W / mK) or not more than 0.2 W / mK or not more than 0.18, 0.17, 0.16, or 0.15 W / mK. Advantageously, the structured paper in the article of the present disclosure helps to lower the thermal conductivity of the article by including air gaps 25 as shown in FIG. IB.

[0052] Furthermore, LFP batery cells tend to expand significantly during thermal runaway. For example, a 24% cell thickness increase was observed by the present inventors. The cell expansion during thermal runaway could lead to challenges in maintaining a reasonable gap to slow down the cell-to-cell heat transfer. The article of the present disclosure has an advantageous stiffness and compression resistance as shown in the Examples, below, which can improve performance of batery modules during normal use and provide protection during thermal runaway.

[0053] Desirably the flame barrier sheet also provides electrical insulation. In some embodiments, the flame barrier sheet has a dielectric breakdown voltage of at least one, two, three, four, or five kilovolts.

[0054] The troughs in the structured paper can be useful for transporting a cooling fluid, either during normal operation or during a failure. For example, cold air may be passed through the troughs, and a cooling liquid may be passed through the troughs in the event of a failure to prevent thermal runaway. In some embodiments of the article and the batery module, at least a portion of the troughs includes a cooling liquid. The present disclosure also provides a method of cooling the batery module described above in any of its embodiments, the method comprising adding a cooling liquid to at least a portion of the troughs. A variety of cooling liquids can be useful, for example, water (e.g., either purified or deionized), ethylene glycol, propylene glycol, mineral oil, and dielectric fluids.

[0055] Some Embodiments of the Disclosure

[0056] In a first embodiment, the present disclosure provides an article comprising: a first sheet of a first non-cellulosic paper having a first major surface and an opposing second major surface; and a structured paper comprising non-cellulosic fibers, the structured paper having ridges and troughs each having an outer surface with land areas, wherein the land areas of at least a portion of the ridges are joined to at least a portion of the first major surface of the first sheet. In a second embodiment, the present disclosure provides the article of the first embodiment, wherein the land areas of at least a portion of the ridges are joined to at least a portion of the first major surface of the first sheet with an adhesive. In a third embodiment, the present disclosure provides the article of the first or second embodiment, further comprising a second sheet of a second non-cellulosic paper joined to at least a portion of the land areas of the troughs of the structured paper, wherein the second non-cellulosic paper may be the same as or different from the first non-cellulosic paper. In a fourth embodiment, the present disclosure provides the article of the third embodiment, wherein the second sheet of the second non- cellulosic paper independently comprises non-cellulosic fibers. In a fifth embodiment, the present disclosure provides the article of the fourth embodiment, wherein the non-cellulosic fibers in the second sheet of the second non-cellulosic paper independently comprise inorganic fibers. In a sixth embodiment, the present disclosure provides the article of the fourth or fifth embodiment, wherein the non-cellulosic fibers in the second sheet of the second non-cellulosic paper independently comprise at least one of organic fibers or aramid fibers. In a seventh embodiment, the present disclosure provides the article of any one of the first to sixth embodiment, wherein the second sheet of the second non-cellulosic paper is not 100 percent by weight meta-aramid fibers. In an eighth embodiment, the present disclosure provides the article of any one of the third to seventh embodiments, wherein the second sheet of the second non- cellulosic paper independently comprises non-fibrous inorganic particles. In a ninth embodiment, the present disclosure provides the article of any one of the third to eighth embodiments, wherein the second sheet of the second non-cellulosic paper independently comprises clay particles. In a tenth embodiment, the present disclosure provides the article of any one of the third to ninth embodiments, wherein the second sheet of the second non-cellulosic paper comprises mica. In an eleventh embodiment, the present disclosure provides the article of any one of the third to tenth embodiments, wherein the second sheet of the second non-cellulosic paper has a thickness of at least one of up to 0.40 mm, up to 0.30 mm, up to 0.20 mm, at least 0.05 mm, at least 0.075 mm, at least 0.10 mm, or in a range from 0.075 mm to 0.2 mm. In a twelfth embodiment, the present disclosure provides the article of any one of the third to eleventh embodiments, wherein the land areas of at least a portion of the troughs are joined to the second sheet with an adhesive.

[0057] In a thirteenth embodiment, the present disclosure provides the article of the second or twelfth embodiment, wherein the adhesive independently comprises at least one of a silicate adhesive or a silicone adhesive. In a fourteenth embodiment, the present disclosure provides the article of any one of the second, twelfth, or thirteenth embodiments, wherein the adhesive is applied discontinuously on the land areas. In a fifteenth embodiment, the present disclosure provides the article of any one of the second, twelfth, or thirteenth embodiments, wherein the adhesive is applied continuously on at least one of first or second opposing structured major surfaces of the structured paper.

[0058] In a sixteenth embodiment, the present disclosure provides the article of any one of the first to fifteenth embodiments, wherein the first sheet of the first non-cellulosic paper independently comprises non-cellulosic fibers. In a seventeenth embodiment, the present disclosure provides the article of any one of the first to sixteenth embodiments, wherein the non-cellulosic fibers in the first sheet independently comprise inorganic fibers. In an eighteenth embodiment, the present disclosure provides the article of any one of the first to seventeenth embodiments, wherein the non-cellulosic fibers in the first sheet independently comprise at least one of organic fibers or aramid fibers. In a nineteenth embodiment, the present disclosure provides the article of any one of the first to eighteenth embodiments, wherein the first sheet of the first non-cellulosic paper is not 100 percent by weight meta-aramid fibers. In a twentieth embodiment, the present disclosure provides the article of any one of the first to nineteenth embodiments, wherein the first sheet of the first non-cellulosic paper independently comprises non-fibrous inorganic particles. In a twenty-first embodiment, the present disclosure provides the article of any one of the first to twentieth embodiments, wherein the first sheet of the first non-cellulosic paper independently comprises clay particles. In a twenty-second embodiment, the present disclosure provides the article of any one of the first to twenty-first embodiments, wherein the first sheet of the first non-cellulosic paper comprises mica. In a twenty-third embodiment, the present disclosure provides the article of any one of the first to twenty-second embodiments, wherein the first sheet of the first non-cellulosic paper has a thickness of at least one of up to 0.40 mm, up to 0.30 mm, up to 0.20 mm, at least 0.05 mm, at least 0.075 mm, at least 0.10 mm, or in a range from 0.075 mm to 0.2 mm.

[0059] In a twenty-fourth embodiment, the present disclosure provides the article of any one of the first to twenty-third embodiments, wherein the non-cellulosic fibers in the structured paper independently comprise inorganic fibers. In a twenty-fifth embodiment, the present disclosure provides the article of any one of the first to twenty-fourth embodiments, wherein the non-cellulosic fibers in the structured paper independently comprise at least one of organic fibers or aramid fibers. In a twenty-sixth embodiment, the present disclosure provides the article of any one of the first to twenty-fifth embodiments, wherein the structured paper has a thickness of at least one of up to 0.40 mm, up to 0.30 mm, up to 0.20 mm, at least 0.05 mm, at least 0.075 mm, at least 0.10 mm, or in a range from 0.075 mm to 0.2 mm. In a twenty-seventh embodiment, the present disclosure provides the article of any one of the first to twenty-sixth embodiments, wherein the structured paper is not 100 percent by weight meta-aramid fibers. In a twenty-eighth embodiment, the present disclosure provides the article of any one of the first to twenty-seventh embodiments, wherein the structured paper independently comprises non-fibrous inorganic particles. In a twenty-ninth embodiment, the present disclosure provides the article of any one of the first to twenty-eighth embodiments, wherein the structured paper independently comprises clay particles. In a thirtieth embodiment, the present disclosure provides the article of any one of the first to twenty-ninth embodiments, wherein the structured paper comprises mica. In a thirty-first embodiment, the present disclosure provides the article of any one of the first to twenty-ninth embodiments, wherein structured paper does not comprise mica.

[0060] In a thirty-second embodiment, the present disclosure provides the article of any one of the first to thirty-first embodiments, wherein the article has a UL 94 rating of at least one of V0 or 5VA. In a thirty-third embodiment, the present disclosure provides the article of any one of the first to thirty-second embodiments, wherein the article has a thermal conductivity of not more than 0.3 watt per meter-kelvin. In a thirty-fourth embodiment, the present disclosure provides the article of any one of the first to thirty- third embodiments, wherein the article has a thickness of not more than 10, 9, 8, 7, 6, 5, 4, 3, or 2 millimeters or not more than one millimeter. In a thirty-fifth embodiment, the present disclosure provides the article of any one of the first to thirty-fourth embodiments, wherein the article has a thickness of at least 0.5 millimeter.

[0061] In a thirty-sixth embodiment, the present disclosure provides a battery module comprising: a plurality of battery cells electrically connected to one another; and the article of any one of the first to thirty-fifth embodiments. In a thirty-seventh embodiment, the present disclosure provides a battery module comprising: an enclosure having a lid and walls; a plurality of battery cells electrically connected to one another within the enclosure, each of the plurality of battery cells optionally comprising a vent; and the article of any one of the first to thirty-fifth embodiments at least one of under the lid, next to the walls of the enclosure, between two of the plurality of battery cells, or above the vent of at least some of the plurality of battery cells. In a thirty-eighth embodiment, the present disclosure provides the battery module of the thirty-seventh embodiment comprising more than one of the articles under the lid, between at least some of the plurality of battery cells, next to the walls of the enclosure, above the vent of at least some of the plurality of battery cells or a combination thereof. In a thirty-ninth embodiment, the present disclosure provides the battery module of any one of the thirty-sixth to thirty-eighth embodiments, wherein at least a portion of the troughs includes a cooling liquid.

[0062] In a fortieth embodiment, the present disclosure provides a method of cooling the battery module of any one of the thirty-sixth to thirty-eighth embodiments, the method comprising adding a cooling liquid to at least a portion of the troughs.

[0063] In a forty-first embodiment, the present disclosure provides a process for making a structured paper, the process comprising: mounting first and second generally cylindrical structuring members in an axially parallel relationship, each of the first and second structuring members having an axis and including a plurality of spaced ridges defining the periphery of the structuring member, the ridges having outer surfaces and defining spaces between the ridges adapted to receive portions of the ridges of the other structuring member in a meshing relationship; rotating at least one of the structuring members; feeding a sheet of paper comprising at least one of inorganic fibers or inorganic particles between the meshed portions of the ridges to generally conform the sheet of paper to the periphery of the first structuring member and form ridges in the structured paper in the spaces between the ridges of the first structuring member and troughs in the structured paper along the outer surfaces of the ridges of the first structuring member. In a forty-second embodiment, the present disclosure provides the process of the forty-first embodiment, further comprising adhering the ridges of the structured paper to a major surface of a first sheet of a first non-cellulosic paper. In a forty-third embodiment, the present disclosure provides the process of the forty-second embodiment, further comprising adhering the troughs of the structured paper to a major surface of a second sheet of a second non-cellulosic paper.

[0064] In a forty-fourth embodiment, the present disclosure provides the process of the forty-third embodiment, wherein at least one of the first sheet or the second sheet independently comprises non- cellulosic fibers. In a forty-fifth embodiment, the present disclosure provides the process of the fortyfourth embodiment, wherein the non-cellulosic fibers in at least one of the first sheet or the second sheet independently comprise inorganic fibers. In a forty-sixth embodiment, the present disclosure provides the process of the forty-fourth or forty-fifth embodiment, wherein the non-cellulosic fibers in at least one of the first sheet or the second sheet independently comprise organic fibers. In a forty-seventh embodiment, the present disclosure provides the process of any one of the forty-fourth to forty-sixth embodiments, wherein the organic fibers comprise aramid fibers. In a forty-eighth embodiment, the present disclosure provides the process of any one of the forty-third to forty-seventh embodiments, wherein at least one of the first sheet or the second sheet is not 100 percent by weight meta-aramid fibers. In a forty-ninth embodiment, the present disclosure provides the process of any one of the forty-third to forty-eighth embodiments, wherein at least one of the first sheet or the second sheet independently comprises non- fibrous inorganic particles. In a fiftieth embodiment, the present disclosure provides the process of any one of the forty-third to forty-ninth embodiments, wherein at least one of the first sheet or the second sheet independently comprises clay particles. In a fifty-first embodiment, the present disclosure provides the process of any one of the forty-third to fiftieth embodiments, wherein at least one of the first sheet or the second sheet comprises mica.

[0065] In a fifty-second embodiment, the present disclosure provides the process of any one of the forty- second to fifty-first embodiments, wherein adhering comprises applying at least one of a silicate adhesive or a silicone adhesive. In a fifty-third embodiment, the present disclosure provides the process of the fifty-second embodiment, wherein applying comprises discontinuously applying on the land areas. In a fifty-fourth embodiment, the present disclosure provides the process of the fifty-second embodiment, wherein applying comprises continuously applying on first and second opposing structured major surfaces of the structured paper. In a fifty-fifth embodiment, the present disclosure provides the process of any one of the forty-third to fifty-fourth embodiments, wherein an article comprising the first sheet, the structured paper, and the second sheet has a thickness of not more than 10, 9, 8, 7, 6, 5, 4, 3, or 2 millimeters or not more than one millimeter.

[0066] In a fifty-sixth embodiment, the present disclosure provides the process of any one of the forty- first to fifty-fifth embodiments, wherein the structured paper independently comprises inorganic fibers. In a fifty-seventh embodiment, the present disclosure provides the process of any one of the forty-first to fifty-sixth embodiments, wherein the structured paper independently comprises organic fibers. In a fiftyeighth embodiment, the present disclosure provides the process of any one of the forty-first to fiftyseventh embodiments, wherein the organic fibers comprise aramid fibers. In a fifty-ninth embodiment, the present disclosure provides the process of any one of the forty-first to fifty-eighth embodiments, wherein the structured paper is not 100 percent by weight meta-aramid fibers. In a sixtieth embodiment, the present disclosure provides the process of any one of the forty-first to fifty-ninth embodiments, wherein the structured paper independently comprises non-fibrous inorganic particles. In a sixty-first embodiment, the present disclosure provides the process of any one of the forty-first to sixtieth embodiments, wherein the structured paper independently comprises clay particles. In a sixty-second embodiment, the present disclosure provides the process of any one of the forty-first to sixty-first embodiments, wherein the structured paper comprises mica. In a sixty-third embodiment, the present disclosure provides the process of any one of the forty-first to sixty-first embodiments, wherein the structured paper does not comprise mica.

[0067] Examples

[0068] Various embodiments of the present disclosure can be better understood by reference to the following Examples which are offered by way of illustration. The present disclosure is not limited to the Examples given herein.

[0069] The following abbreviations are used in the Examples, cm = centimeter, mm = millimeter, mil = thousandth of an inch, ft = feet, min = minute, seconds = s, °C = degrees Celsius, °F = degrees Fahrenheit, psi = pounds per square inch, kPa = kilopascal, W / mK = watts per meter-kelvin, g =gram, g / cc = grams per cubic centimeter, g / cm3= grams per cubic centimeter, gsm = grams per square meter, N = Newton, kN = kilonewton.

[0070] Examples 1 and 2

[0071] FBP1 was fed into the nip between first and second intermeshing rollers, which were machined with axially parallel ridges spaced such that there were approximately 4 ridges per cm with a groove between each ridge. Each ridge was machined to have a flat top-surface having a width of about 0.7 mm, and the top surfaces had a maximum width of 1 mm. Both rolls were operated at a fixed temperature of 300 °F (149 °C) and line speed of 3 ft / min (91 cm / min). The gap between the rolls was 97 mil (2.46 mm) for a final structured FBP1 thickness of 0.82 mm, as depicted by “t” in FIG. IB.

[0072] The structured paper was cut to the size indicated for each test method, below. The structured FBP1 was roll coated by hand on both sides with SS using a 3M Safety-Walk rubber hand roller 903 from 3M Company. This resulted in the adhesive being located only on the land areas. Both surfaces were adhered to FBP1 sheets to prepare Example 1, having a total thickness of one mm. In a separate sample, both surfaces were adhered to MC to prepare Example 2, having a total thickness of 1.7 mm. All samples were then heated for 15 minutes in a convection oven set at 120 °C.

[0073] When FBP1 was fed into the nip between first and second intermeshing rollers according to the method of Examples 1 and 2, but with a gap between the rolls of 92 mil (2.34 mm) or 85 mil (2.16 mm), the structured paper had a tear percentage of 25% and 100%, respectively. Tear percentage was calculated by looking at 20 valleys of the ribs and counting the number of valleys with tear / defect spanning more than half of the sample width. The tear percentage was decreased by application of water sprayed water directly onto the FBP1 paper at about 10 percent by weight or by soaking the FBP1 paper in water at a level of about 54% by weight. Sandwiching the paper between two polyethylene terephthalate (PET) webs (FINON C303 NW (Midwest Filtration LLC, Cincinnati, OH), 5 mils (127 micrometers) thick, 30.5 gsm) resulted in no tearing with a gap between the rolls of 92 mil (2.34 mm), 85 mil (2.16 mm), or 75 mils (1.91 mm).

[0074] Examples 3 to 9

[0075] For Examples 3 to 7, FBP1 was fed into the nip between first and second intermeshing rollers according to the method of Examples 1 and 2 with the modification that the gap between the rolls was 91 mil (2.31 mm) for a final structured thickness of 0.8 mm.

[0076] IP was stiffer than FBP1 and nonuniform to the naked eye. The final structured thickness was shallower than the FBP1 with a 91 mil (2.31 mm) gap. For Examples 8 and 9, an 88 mil (2.24 mm) gap was used for a final structured IP thickness of 0.7 mm to 0.75 mm.

[0077] The structured paper was cut to the size indicated for each test method, below.

[0078] The adhesive shown in Table 2 below was applied evenly on both sides of the structured paper by hand at approximately 250 gsm using a brush. For Examples 4 to 9, SE was prepared by mixing the precursor to curing agent in a ratio of 10: 1 by weight. The mixture was thoroughly mixed using a wooden spatula in a plastic petri dish for several minutes before being applied using a brush. Then the coated structured paper was sandwiched between two sheets of paper. All examples were then heated for 15 minutes in a convection oven set at 120 °C. The adhesive and materials used for the structured paper and sheets of paper for each of Examples 3 to 9 are shown in Table 2, below. Table 2. Examples 3 to 9

[0079] Illustrative Examples A and B

[0080] Both MA and MB shredded into pieces when fed into the nip between first and second intermeshing rollers according to the method of Examples 1 and 2 with the modification that the gap between the rolls was 91 mil (2.31 mm). Flakes were also depositing into the grooves of the rollers. A structured paper could not be made.

[0081] Thermal Conductivity: The thermal impedance of samples of Examples and starting materials were measured using a

[0082] DTC-300 instrument obtained from Waters / TA Instruments, New Castle, DE, USA at 50 °C, 25 psi (172 kPa). The sample was prepared by making a 65 mm by 65 mm square sample and die cutting out a two- inch (5.08-cm) disc. Three replicate measurements were taken for each sample type. The average effective thermal conductivity for each is shown in Table 3, below.

[0083] Table 3. Thermal conductivity values of the starting materials and Examples Flame Test:

[0084] UL94 Classification and Flame -Retardant Thermoplastic standard released by the Underwriters Laboratories (USA). The sample size was 125 mm long x 13 mm wide strips. If burning stopped within 10 seconds on a vertical part (VO), then the test standard considers it a pass. The time it took a sample, while being subjected to the test, to self-extinguish was recorded. Six samples were tested for each example. Examples 4, 5, and 6 were tested for the UE94 test, and all samples passed the UE94 VO criteria. The edge of the samples ignited for a short period with no drip. Notably, Example 5 had a longer after-flame time than the other Examples.

[0085] Three-Point Bend Test

[0086] Mechanical properties were measured in compression using an Instron Mechanical Testing model #5969 (Instron, Norwood, MA, USA) equipped with a 3 -point bending apparatus, a 5 kN bending fixture sold by Instron. The test was conducted following a modified ASTM D790-17 test standard. A 10-kN load cell was used, and the compression rate was 10.75 mm / min, calculated based on the FBP1 paper thickness following Procedure A for bar samples laying flat with a thickness of less than 1.6 mm. All samples were tested at the same compression rate as the FBP1 paper for simplicity. Samples were cut to 50.8 mm (2 inches) long and 12.7 mm (1 / 2 inch) wide, except for Example 2. For Example 2, a larger piece 2.5 inches (6.35 mm) long and 45 mm wide was used. The span between the support bars was kept at 25.4 mm (1 inch), as recommended by the test standard. The test stopped compressing at 5 mm displacement. The results are shown in Table 4, below.

[0087] Table 4. Three-Point Bend values of the starting materials and Examples (Ex.) ‘'Parallel refers to the 3-point bend probe being oriented parallel to the direction of the ridges and troughs.bNormal refers to the 3-point bend probe being oriented perpendicular to the direction of the ridges and troughs.cTwo sheets of MC were stacked together.

[0088] Compression Test

[0089] A compression test was carried out on Examples 3 to 6. The test followed a modified ASTM D3574. The sample thickness and the compression starting point were defined at 0.5 N compression stress. The compression rate was 5 mm / minute, and the sample size was 65 mm by 65 mm square. The compression strain was 50%, and the same sample was repeated thrice, with a 1-minute interval after each compression cycle. The results of the first and third cycle are shown in Table 5, below. All samples showed a large Mullins effect, where the first compression had a nonrecoverable deformation.

[0090] Table 5. Compression of Examples (Ex.) 3 to 6

[0091] Density

[0092] Density was determined for Examples 3 and 4 by weighing a sample and dividing the weight by the volume of the sample. The size of the specimen was 65 mm by 65 mm square. The following equation was used: Mass of 65 mm square / (6.5x6.5xthickness in cm) = g / cc = g / cm3. The results are shown in Table 6, below. The thickness is “T” as depicted in FIG. IB. Table 6. Density of Examples 3 and 4

[0093] Examples 10 and 11 - Battery Module

[0094] Three fully charged (100% state of charge) LFP batteries were placed adjacent to each other in an insulated enclosure. In Example 10, Example 4 articles were positioned above the cell vents and between the three cells in the manner shown in FIG. 3. In Example 11, Example 5 articles were positioned above the cell vents and between the three cells in the manner shown in FIG. 3. Thermocouples were placed close to the vent of one of the cells, under the article, and close to the vent, under the top cover but over the article. The one cell was triggered by overheating. Thermocouples were also placed on the overheating cell and the adjacent cells. The results are shown in Table 7, below.

[0095] Table 7. Temperatures measured for Examples 10 and 11 During Thermal Runaway

[0096] The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the embodiments of the present disclosure. Thus, it should be understood that although the present disclosure has been specifically disclosed by specific embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those of ordinary skill in the art, and that such modifications and variations are considered to be within the scope of embodiments of the present disclosure.

Claims

What is claimed is:

1. An article comprising: a first sheet of a first non-cellulosic paper having a first major surface and an opposing second major surface; and a structured paper comprising non-cellulosic fibers, the structured paper having ridges and troughs each having an outer surface with land areas, wherein the land areas of at least a portion of the ridges are joined to at least a portion of the first major surface of the first sheet.

2. The article of claim 1, wherein the land areas of at least a portion of the ridges are joined to at least a portion of the first major surface of the first sheet with an adhesive.

3. The article of claim 1 or 2, further comprising a second sheet of a second non-cellulosic paper joined to at least a portion of the land areas of the troughs of the structured paper with an adhesive, wherein the second non-cellulosic paper is the same as or different from the first non-cellulosic paper.

4. The article of claim 2 or 3, wherein the adhesive independently comprises at least one of a silicate adhesive or a silicone adhesive.

5. The article of any one of claims 2 to 4, wherein the adhesive is applied continuously on at least one of first or second opposing structured major surfaces of the structured paper.

6. The article of any one of claims 1 to 5, wherein at least one of the first sheet, the second sheet, or the structured paper independently comprises at least one of inorganic fibers or non-fibrous inorganic particles.

7. The article of any one of claims 1 to 6, wherein at least one of the first sheet, the second sheet, or the structured paper independently comprises aramid fibers.

8. The article of any one of claims 1 to 7, wherein at least one of the first sheet, the second sheet, or the structured paper is not 100 percent by weight meta-aramid fibers.

9. The article of any one of claims 1 to 8, wherein at least one of the first sheet, the second sheet, or the structured paper independently comprises clay particles.

10. The article of any one of claims 1 to 9, wherein structured paper does not comprise mica.

11. The article of any one of claims 1 to 10, wherein the article has a UL 94 rating of at least one of VO or 5VA.

12. The article of any one of claims 1 to 11, wherein the article has a thickness of not more than 10 millimeters.

13. A battery module comprising: an enclosure having a lid and walls; a plurality of battery cells electrically connected to one another within the enclosure; and the article of any one of claims 1 to 12 at least one of under the lid, between two of the plurality of battery cells, or next to the walls of the enclosure.

14. A method of cooling the battery module of claim 13, the method comprising adding a cooling liquid to at least a portion of the troughs.

15. A process for making the article of any one of claims 1 to 14, the process comprising: mounting first and second generally cylindrical structuring members in an axially parallel relationship, each of the first and second structuring members having an axis and including a plurality of spaced ridges defining the periphery of the structuring member, the ridges having outer surfaces and defining spaces between the ridges adapted to receive portions of the ridges of the other structuring member in a meshing relationship; rotating at least one of the structuring members; feeding a sheet of paper comprising non-cellulosic fibers between the meshed portions of the ridges to generally conform the sheet of paper to the periphery of the first structuring member and form the ridges in the structured paper in the spaces between the ridges of the first structuring member and the troughs in the structured paper along the outer surfaces of the ridges of the first structuring member; and joining the ridges of the structured paper to the first major surface of the first sheet of non- cellulosic paper.

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