Rapid induction sinter forging for roll-to-roll continuous production of thin films

Abstract

A method and apparatus for sinter-forging a precursor powder to form a film can reduce or eliminate stress in the film and facilitate the fabrication of continuous lengths of film, such as ceramic membranes for use in batteries. The precursor powder can be supplied onto a substrate and simultaneously heated and pressed in a pressing direction parallel to the film thickness, causing the precursor powder to sinter and densify to form a film in a sinter-forged region. In particular, in a plane perpendicular to the pressing direction, there is no lateral constraint on the sinter-forged region or the material received therein.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is based on and claims priority to U.S. Provisional Patent Application No. 62 / 968,739, filed January 31, 2020, the entire contents of which are incorporated herein by reference for all purposes.

[0002] <Statement Regarding Federally Sponsored Research> This invention was made with government support under award DE-AR0000653 awarded by the U.S. Department of Energy. The government has certain rights in this invention.

[0003] The present disclosure relates to an apparatus and method for forming thin films by rapid induction sinter forging. [Background technology]

[0004] The conversion of loosely bound powders into dense compacts at high temperatures is a common and widespread method for manufacturing materials and components. Traditionally, a loosely bound collection of powder particles, known as a green body or compact, is sintered together at elevated temperatures close to but not exceeding the melting temperature of the particles being sintered together, causing the particles to diffuse together and form necks, thereby forming a unified sintered body. Generally, sintering uses solid-state diffusion only, meaning that the powder materials being sintered do not melt at all during sintering; however, in limited circumstances or with specific powder chemistries and morphologies, a small amount of liquid phase may be generated during the sintering process. During sintering, as the various particles diffusely bond together, porosity initially forms between the particles as they form necks. As sintering progresses, the amount of porosity decreases, resulting in a corresponding loss of volume. The resulting compact is denser than the starting unsintered green body or compact.

[0005] Because defects in sintered materials play a significant role in their properties and performance, methods to eliminate processing defects are crucial for optimizing manufacturing processes involving sintered products ([References 1, 2]). While free-form sintering uses only high temperatures to densify powder compacts, other supporting techniques exist, such as hot pressing (HP) and hot isostatic pressing (HIP), that combine high temperatures and high pressures to enhance densification transport mechanisms and eliminate defects caused by powder packing inhomogeneities ([References 1-4]). Both HP and HIP require the green body to be enclosed in a mold (HP) or a pressurized fluid (HIP). Another technique, sinter forging, also involves the application of high temperatures and uniaxially high pressures ([References 5, 6]). Summary of the Invention [Problem to be solved by the invention]

[0006] What is needed is a method to further eliminate defects in sintered articles. [Means for solving the problem]

[0007] To further eliminate defects in sintered products, particularly thin films, it is disclosed herein that, in appropriate configurations, sinter-forging without lateral constraints can be employed. Such sinter-forging without lateral constraints may be well suited to continuous manufacturing processes for the production of thin films. We propose the design of a system for scalable sinter-forging of dense thin film materials with precise control of processing conditions (e.g., temperature, pressure, gas environment).

[0008] As noted above, microstructural defects formed during the compression of powder into a sintered compact are often caused by non-uniform powder packing, resulting in uneven sintering. Techniques such as hot pressing and hot isostatic pressing can help eliminate these defects, but the need for powder encapsulation can result in residual shear stresses in the sintered material and make scalable, highly productive manufacturing difficult to achieve. The disclosed material densification method differs from hot pressing and hot isostatic pressing in that it uses a combination of temperature and pressure without lateral constraint. The lack of lateral constraint from a die or containment vessel allows for shear deformation during sintering, thereby eliminating residual shear stresses. The sinter forging disclosed herein enables continuous manufacturing in a manner similar to roll-to-roll processing. This disclosure presents designs for sinter forging apparatus and methods that operate using rapid induction heating and can enable the continuous production of dense thin films of material.

[0009] In one aspect, a method for sinter-forging a precursor powder to form a film is provided. The precursor powder is provided on a substrate. Heat and pressure are simultaneously applied to the precursor powder while pressing the precursor powder in a direction parallel to the film thickness to sinter and densify the precursor powder to form a film in the sinter-forged region. In a plane perpendicular to the pressing direction, the sinter-forged region is free from lateral constraint.

[0010] In some embodiments, the absence of lateral constraint in the sinter forged region allows the precursor powder to deform and pressure-assisted sinter during film formation, reducing the formation of residual shear stresses in the film. In some embodiments, the simultaneous application of heat and pressure causes the precursor powder to deform and pressure-assisted sinter to produce a dense ceramic body.

[0011] In some embodiments, frictional stress between the membrane and substrate creates a hydrostatic stress state in the membrane during sintering. In some embodiments, a combination of stress from applied pressure and frictional pressure creates a hydrostatic stress state in the membrane during sintering. The adhesion is good enough to mechanically support the membrane, but weak enough to delaminate when it is desired to form a metal anode in situ between the substrate (e.g., current collector) and membrane (e.g., ceramic electrolyte).

[0012] In some embodiments, when the precursor powder is not simultaneously heated and pressurized (and any press element, such as a piston, is elevated), the substrate may be movable in a direction generally perpendicular to the direction of pressure. When the substrate and powder are movable, the method may further include repeatedly performing the steps of (a) simultaneously heating and pressurizing the precursor powder to form a film, (b) removing the pressure on the film, and (c) advancing the precursor powder and substrate to introduce the as-yet-unsintered precursor powder into the sinter-forging zone. In this manner, a continuous length of substrate having a length exceeding the maximum dimension of the sinter-forging zone may have one or more films formed by repeated sinter-forging.

[0013] In some embodiments, the step of simultaneously applying heat and pressure to the precursor powder is performed by a piston that is part of an apparatus that can articulate the piston in and out of the sinter-forging area. In this case, the method may further include the step of heating the piston using induction heating from an induction coil surrounding the piston. In such a configuration, the piston could be constructed of graphite or another material that is structurally capable of applying pressure and that is heatable by induction heating (i.e., can withstand induction heating). In some embodiments, prior to the step of simultaneously applying heat and pressure to the precursor powder, a release layer can be applied to prevent adhesion between the piston and the film. Such a release layer can be, for example, nickel foil.

[0014] In some embodiments, the method may further include heating the substrate using induction heating with an induction coil surrounding the substrate.

[0015] In some embodiments, the method may further include providing an environmental gas around the sinter forging area.

[0016] In some embodiments, the precursor powder may be part of a powder slurry, or the precursor powder may be a dry powder. It is contemplated that the precursor powder may be metallic or ceramic. The precursor powder used in the following examples is a ceramic powder that can be used to form ceramic thin films for battery fabrication. The precursor powder may include a binder selected from the group consisting of polyvinylidene fluoride, poly(methyl methacrylate), poly(vinyl acetate), polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, polyvinyl ether, polytetrafluoroethylene, polyacrylate, polyvinyl chloride, polyacrylonitrile, polyvinyl pyridine, styrene butadiene rubber, acrylonitrile butadiene rubber, polyethylene, polypropylene, ethylene propylene diene terpolymer, cellulose, carboxymethyl cellulose, starch, hydroxypropyl cellulose, and mixtures thereof.

[0017] In some embodiments of the method, the sintered film comprises a solid electrolyte material which may be any combination of garnet, perovskite, NaSICON, or LiSICON phase oxide or phosphate materials.

[0018] In some embodiments of the method, the sintered film comprises Li w A x M2Re 3-y O z and a solid electrolyte material comprising a ceramic material having a chemical formula of: w is 5 to 7.5, A is selected from B, Al, Ga, In, Zn, Cd, Y, Sc, Mg, Ca, Sr, Ba, and any combination thereof; x is 0 to 2, M is selected from Zr, Hf, Nb, Ta, Mo, W, Sn, Ge, Si, Sb, Se, Te, and any combination thereof; Re is selected from the group consisting of a lanthanide element, an actinide element, and any combination thereof; y is between 0 and 0.75; z is 10.875 to 13.125, The ceramic material has a garnet-type or garnet-like crystal structure.

[0019] In some embodiments of the method, the sintered film comprises a sulfide-based solid electrolyte material comprising at least lithium, sulfur, and phosphorus. The sulfide-based solid electrolyte material is Li7P3S 11 , Li7PS6, Li4P2S6, Li3PS6, Li3PS4, Li2P2S6, Li 10 GeP2S 12 (LGPS), and Li 7-x PS 6-x Cl x , Li 7-x PS 6-x Br x , Li 7-x PS 6-x I x , (where 0≦x≦2).

[0020] In some embodiments of the method, the sintered film comprises a lithium host material, which can be selected from the group consisting of: (i) lithium metal oxides, where the metal is one or more of aluminum, cobalt, iron, manganese, nickel, and vanadium, and (ii) lithium-containing phosphates having the general chemical formula of LiMPO4, where M is one or more of cobalt, iron, manganese, and nickel.

[0021] In some embodiments of the method, the step of simultaneously heating and pressurizing the precursor powder includes heating at a temperature between 30° C. and 2000° C. and applying a pressure between 1 MPa and 500 MPa. In some embodiments, the step of simultaneously heating and pressurizing the precursor powder includes heating at a temperature between 500° C. and 1300° C. and applying a pressure between 1 MPa and 50 MPa. Of course, these temperatures are exemplary, and the temperature and pressure ranges to be achieved may be a function of the precursor powder being formed into a film, with temperature, pressure, and time being variables that may be altered to produce a sintered film of desired density and microstructure.

[0022] In some embodiments of the method, the sintered film has a relative density of greater than 90% in a sinter-forging time of less than 90 minutes. In some embodiments, the sintered film has a relative density of greater than 98% in a sinter-forging time of less than 5 minutes.

[0023] In some embodiments of the method, the sintered film has a thickness of 1 nm to 500 μm. In some embodiments, the sintered film has a thickness of 1 nm to 100 μm. In some embodiments of the method, the substrate has a thickness of 1 nm to 100 μm.

[0024] In some embodiments of the method, the substrate comprises a metallic material selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, alloy steel, carbon steel, stainless steel, nickel-based superalloy, cobalt-based superalloy, copper, aluminum, iron, or a mixture thereof. In some embodiments of the method, the substrate comprises a bimetal having a first layer comprising a first metallic material and a second layer comprising a second metallic material. The first metallic material can be selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, nickel-based superalloy, cobalt-based superalloy, copper, or a mixture thereof, and the second material can be selected from the group consisting of aluminum, nickel, alloy steel, carbon steel, stainless steel, nickel-based superalloy, or a mixture thereof. In some embodiments of the method, the first metallic material comprises nickel and the second material comprises stainless steel. In some embodiments, the first layer has a thickness of 1 nm to 100 μm and the second layer has a thickness of 1 nm to 100 μm.

[0025] In some embodiments of the method, a layer of graphite particles is disposed between the substrate and the precursor powder, hi some embodiments, the layer of graphite particles has a thickness of 1 μm to 10 μm.

[0026] According to another aspect, an apparatus for sinter-forging a precursor powder onto a substrate to form a film is provided. The apparatus includes a load frame, a piston, and a set of induction coils. The load frame has a sinter-forging area defined therein for receiving the precursor powder. The piston is resistant to induction heating and can be actuated by the load frame in a pressing direction to simultaneously heat and pressurize the precursor powder received in the sinter-forging area. The set of induction coils is concentric with the piston so that the piston can be heated by high-frequency induction. The sinter-forging area is located along a plane perpendicular to the pressing direction, and the sinter-forging area is free of lateral constraints.

[0027] In some embodiments, the absence of lateral constraint in the sinter forged region allows the precursor powder to deform and pressure-assisted sinter during film formation, reducing the formation of residual shear stresses within the film. In some embodiments, the simultaneous application of heat and pressure induces deformation and pressure-assisted sintering of the precursor powder to produce a dense ceramic body. In some embodiments, frictional stress between the film and substrate creates a hydrostatic stress state within the film during sintering. In some embodiments, the combined stresses from the applied pressure and frictional pressure create a hydrostatic stress state within the film during sintering.

[0028] In some embodiments, the apparatus may further include a non-conductive shroud surrounding the piston, defining a hollow cavity between the piston and the non-conductive shroud, the hollow cavity opening into the sinter-forging region. A gas inlet in fluid communication with the hollow cavity may be configured to supply gas flowing from the gas inlet into the hollow cavity, over the piston, through the hollow cavity, and to an ambient environment of the sinter-forging region.

[0029] In some embodiments, the apparatus may further include a transport mechanism for advancing the precursor powder and substrate through the sinter forging region, which can be used to easily produce continuous lengths of film suitable for cutting to desired lengths.

[0030] In some embodiments, the apparatus may further include a system for controlling the temperature of the substrate comprising one or more of a thermocouple, a temperature controller, and a coolant circulator.

[0031] In some embodiments, the piston may comprise graphite. However, regardless of the material, it is believed that the piston may be heated to a temperature of 500°C to 1300°C by a set of induction coils and subjected to a pressure of 1 MPa to 50 MPa by a load frame in a sinter-forging area. In some embodiments, the piston may be heated to a temperature of 30°C to 2000°C by a set of induction coils and subjected to a pressure of 1 MPa to 500 MPa by a load frame in a sinter-forging area.

[0032] According to another aspect, a method for forming an electrochemical device including an array of spaced-apart sintered films is provided, the method including supporting spaced-apart portions of a precursor powder on a substrate, simultaneously heating and pressing the spaced-apart portions of the precursor powder in a pressure direction parallel to the thickness of the spaced-apart portions of the precursor powder to form spaced-apart sintered films on the substrate, and depositing a flexible material between the spaced-apart sintered films on the substrate.

[0033] In one embodiment of the method, each separate sintered membrane is created in a separate sinter-forged zone, with each sinter-forged zone being free of lateral constraint in a plane perpendicular to the pressing direction. The free lateral constraint in each sinter-forged zone allows for deformation and pressure-assisted sintering of the precursor powder during formation of the sintered membrane, reducing the formation of residual shear stresses within each sintered membrane. In some embodiments, simultaneous application of heat and pressure induces deformation and pressure-assisted sintering of the precursor powder to produce a dense ceramic body. In some embodiments, frictional stress between the membrane and substrate creates a hydrostatic stress state within the membrane during sintering. In some embodiments, the combined stress of applied pressure and frictional pressure creates a hydrostatic stress state within the membrane during sintering. The adhesion is good enough to mechanically support the membrane, but weak enough to delaminate if in situ formation of a metal anode between the substrate (e.g., current collector) and membrane (e.g., ceramic electrolyte) is desired.

[0034] In one embodiment of the method, the substrate is movable in a direction generally along a plane perpendicular to the direction of pressure when the spaced portions of the precursor powder are not simultaneously heated and pressured.

[0035] One embodiment of the method further includes repeatedly performing the steps of (a) simultaneously applying heat and pressure to spaced portions of the precursor powder to form spaced sintered films; (b) removing the pressure on the spaced sintered films; (c) advancing a substrate to introduce the still unsintered spaced portions of the precursor powder into a sinter forging region; and (d) depositing a flexible material on the substrate between the spaced sintered films, thereby forming an array of continuous lengths of spaced sintered films surrounded by the flexible material by the repeated sinter forging.

[0036] In this method, the separated sintered films can include a solid electrolyte material which can be any combination of garnet, perovskite, NaSICON, or LiSICON phase oxide or phosphate materials. w A x M2Re 3-y O z The solid electrolyte material may comprise a ceramic material having a chemical formula of: w is 5 to 7.5, A is selected from B, Al, Ga, In, Zn, Cd, Y, Sc, Mg, Ca, Sr, Ba, and any combination thereof; x is 0 to 2, M is selected from Zr, Hf, Nb, Ta, Mo, W, Sn, Ge, Si, Sb, Se, Te, and any combination thereof; Re is selected from the group consisting of lanthanides, actinides, and any combination thereof; y is between 0 and 0.75; z is 10.875 to 13.125, The ceramic material has a garnet-type or garnet-like crystal structure.

[0037] In this method, the separated sintered films may comprise a sulfide-based solid electrolyte material containing at least lithium, sulfur, and phosphorus. The sulfide-based solid electrolyte material may be Li7P3S 11 , Li7PS6, Li4P2S6, Li3PS6, Li3PS4, Li2P2S6, Li 10 GeP2S 12 (LGPS), and Li 7-x PS 6-x Cl x , Li 7-x PS 6-x Br x and Li 7-x PS 6-x I x (wherein 0≦x≦2).

[0038] In this method, the separated sintered film can include a lithium host material selected from the group consisting of (i) lithium metal oxides, where the metal is one or more of aluminum, cobalt, iron, manganese, nickel, and vanadium, and (ii) lithium-containing phosphates having the general chemical formula of LiMPO4, where M is one or more of cobalt, iron, manganese, and nickel.

[0039] In this method, the flexible material can comprise a polymeric material selected from the group consisting of polyolefins, polystyrene, divinylbenzene, ethylene vinyl acetate polymers and copolymers, silicone polymers, styrene-divinylbenzene copolymers, and blends and mixtures thereof.

[0040] In some embodiments of the method, the precursor powder comprises a binder, which may be selected from the group consisting of polyethylene oxide, polyvinylpyrrolidone, polyvinyl ether, polytetrafluoroethylene, polyacrylate, polyvinyl chloride, polyacrylonitrile, polyvinylpyridine, styrene butadiene rubber, acrylonitrile butadiene rubber, polyethylene, polypropylene, ethylene propylene diene terpolymer, cellulose, carboxymethyl cellulose, starch, hydroxypropyl cellulose, and mixtures thereof.

[0041] In some embodiments of the method, the separated sintered film has a thickness of 1 nm to 500 μm. In some embodiments of the method, the separated sintered film has a thickness of 1 nm to 100 μm. In some embodiments of the method, the substrate has a thickness of 1 nm to 100 μm.

[0042] In some embodiments of the method, the substrate comprises a metallic material selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, alloy steel, carbon steel, stainless steel, nickel-based superalloy, cobalt-based superalloy, copper, aluminum, iron, or mixtures thereof.

[0043] In some embodiments of the method, the substrate comprises a bimetal having a first layer comprising a first metallic material and a second layer comprising a second metallic material. The first metallic material can be selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, nickel-based superalloys, cobalt-based superalloys, copper, or mixtures thereof, and the second material is selected from the group consisting of aluminum, nickel, alloy steel, carbon steel, stainless steel, nickel-based superalloys, or mixtures thereof. In some embodiments of the method, the first metallic material comprises nickel and the second material comprises stainless steel. In some embodiments of the method, the first layer has a thickness of 1 nm to 100 μm, and the second layer has a thickness of 1 nm to 100 μm.

[0044] In some embodiments of the method, a layer of graphite particles is disposed between the substrate and the precursor powder. The layer of graphite particles can have a thickness of 1 μm to 10 μm.

[0045] These and other features, aspects, and advantages of the present disclosure will become better understood with consideration of the following detailed description, drawings, and appended claims. [Brief explanation of the drawings]

[0046] [Figure 1a] 1 is a schematic front view of a sinter forging apparatus according to one embodiment of the present disclosure. FIG. [Figure 1b] 1 is a schematic cross-sectional side view of a sinter forging apparatus according to one embodiment of the present disclosure. [Figure 2] 1A-1C are cross-sectional images taken by scanning electron microscope (SEM) of LLZO films according to various embodiments of the present disclosure, where image (a) is sinter-forged at 1150°C for 20 minutes, image (b) is sinter-forged at 1250°C for 5 minutes, and image (c) is sinter-forged at 1250°C for 2 minutes. [Figure 3] FIG. 2 is a top view of a sinter forging apparatus according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0047] Before describing the present invention in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein. Moreover, the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting of the present invention. The scope of the present invention is limited only by the claims. As used herein, the singular forms "a," "an," and "the" include plural embodiments unless the context clearly dictates otherwise.

[0048] It will be apparent to those skilled in the art that, in addition to the aspects already described, many other modifications of the present invention are possible without departing from the spirit of the present invention. In interpreting this disclosure, all terms should be interpreted in the broadest possible sense consistent with the context. Variations of the terms "comprises," "includes," or "has" should be interpreted as referring non-exclusively to elements, components, or steps, such that the referenced element, component, or step may be combined with other elements, components, or steps not expressly mentioned. Embodiments described as "comprising," "including," or "having" a particular element also encompass "consisting essentially of" and "consisting of" that element, unless the context clearly dictates otherwise. Aspects of the present disclosure described with respect to a system should be understood to also apply to a method, and vice versa, unless the context clearly dictates otherwise.

[0049] Numerical ranges disclosed herein are inclusive. For example, a numerical range of 1 to 10 includes the values ​​1 and 10. When multiple consecutive numerical ranges are disclosed for a particular value, the present disclosure expressly contemplates ranges including all combinations of the upper and lower limits of each of those multiple numerical ranges. For example, a numerical range of 1 to 10 or a numerical range of 2 to 9 is intended to include the numerical range of 1 to 9 and the numerical range of 2 to 10.

[0050] As used herein, "green body" or "compact" refers to a loosely bound collection of powder particles, which may be metallic, ceramic, or both. "Sintering" refers to a high temperature process for reducing porosity in a material, typically a green body or compact, and producing a dense compact.

[0051] As used herein, "roll-to-roll" refers to a type of continuous manufacturing process in which materials, structures, or devices are printed, coated, or patterned onto or embedded within a rolled flexible substrate. Such roll-to-roll processes are described, for example, in U.S. Patent Application Publication No. 2017 / 0222254, published August 3, 2017, by Sakamoto et al., the entire contents of which are incorporated herein by reference for all purposes.

[0052] As used herein, "rapid induction heating" refers to a method that uses electromagnetic induction to transfer energy to heat a receiver material at a high heating rate.

[0053] The disclosed apparatus and associated methods utilize a combination of a load frame and rapid induction heating, enabling highly productive thin-film sinter forging compatible with roll-to-roll manufacturing. Generally speaking, the disclosed apparatus and methods can be used to sinter a region of powder formed on a rolled metal foil. After the powder is formed on the metal substrate, it is conveyed under a pressure piston, which is rapidly heated by electromagnetic induction. The piston, connected to the load frame, contacts the formed powder / green film and applies uniaxial compression using the load frame. Meanwhile, environmental gas can flow through an inlet, enveloping the piston and powder. After a given period of pressure application, the powder is compressed into a dense sintered film, and the piston is lifted. At this point, the sintered film can be removed, and a new green film (or a new portion of green film) can be introduced for sinter forging. Using this system and these methods, 70 μm ceramic thin films with relative densities exceeding 98% have been demonstrated in less than 5 minutes of sinter forging time. However, it is believed that these methods can be used to produce thin films up to 1 mm thick. In one embodiment of the method, the thickness of the sintered thin film is between 1 nm and 100 μm. For ease of understanding, thickness should be understood as the dimension of the film parallel to the direction of punch pressure and perpendicular to the plane that contacts the top surface of the thin film.

[0054] <System design> The proposed sinter-forging system and apparatus is shown in Figures 1a and 1b. The proposed apparatus 10 consists of three main components: a load frame 12, an induction heater including an induction coil 14, and a sample substrate 16 that supports a sample 34. Prior to sinter-forging, the sample 34 may be a green powder, for example, in the form of either a compacted powder slurry or a dry powder, and after sinter-forging, the sample 34 is in the form of a sintered thin film.

[0055] The system can utilize a commercial load frame to measure and control the applied pressure. As shown in FIGS. 1a and 1b, the load frame 12 includes a crosshead 18 and an intermediate mount 20 connected to a piston 22 to transfer force from the crosshead 18 to the piston 22. While not fully illustrated, the load frame 12 can be any load frame known in the art. For example, the load frame can be a load frame such as those commonly manufactured by Instron® Corporation of Norwood, Massachusetts, USA, or TA® Instruments, Inc. of New Castle, Delaware, USA. However, the particular load frame employed could be a hydraulic or electrohydraulic press rather than a compact electromechanical load frame to facilitate serial production and accommodate the desired production scale. The piston 22 can be formed of a material that can withstand induction heating and has sufficient mechanical strength to apply forging pressure, such as a graphite material.

[0056] In addition to providing a mechanical connection between the crosshead 18 and the piston 22, the intermediate mount 20 can also be used to support a shroud 24. The shroud 24 can be a non-conductive material, such as quartz, and can shield the piston 22 from the induction coil 14 while also containing an environmental gas. The environmental gas can be supplied by a gas supply 26 (shown primarily in FIGS. 1a and 1b as a supply gas conduit) having a gas inlet 28 in fluid communication with the volume between the piston 22, the intermediate mount 20, and the shroud 24. As shown, the gas inlet 28 is located on the intermediate mount, and gas flows through the volume between the shroud 24 and the piston 22 and exits through a gas outlet 30 near a sinter forging region 32 where the material is heated and pressurized.

[0057] Temperature control may be achieved using commercially available induction heaters and temperature controllers. Piston 22 may be heated by electromagnetic induction when it enters the region within induction coil 14. Sample temperature is measured by a thermocouple within substrate 16 and controlled by a temperature controller, which adjusts the power output of coil 14. Alternatively, the substrate may be heated using induction heating with an induction coil surrounding the substrate.

[0058] Finally, the sample substrate 16 serves as a support for the sample 34 during sinter-forging and can be incorporated into a roll-to-roll process, where a continuous roll of metal substrate moves beneath the sinter-forging piston 22.

[0059] <Material processing> In an exemplary process using apparatus 10, an exemplary ceramic precursor powder for densification is a powder having the composition Li 6.5 La3Zr 1.5 Ta 0.5 O 12Garnet-structured lithium lanthanum zirconium oxide (LLZO) was used. LLZO powder was synthesized by solid-state synthesis as described by Rangasamy (Reference 7) and then mixed into a slurry containing a solvent, a dissolved polymer binder, and a plasticizer. The slurry was then cast onto a 35 μm-thick Ni foil (Targray) using a doctor blade. After drying, the resulting green film was placed on a graphite substrate and covered with another Ni foil with a 200 nm sputtered C layer, which served as a release layer to prevent adhesion between the sample and the sintered forged piston. The green film was then heated in Ar at a pressure of 6 MPa and a temperature ramp rate of approximately 3°C / s. -1 The films were sinter-forged at varying temperatures. The peak temperature (mentioned elsewhere in this disclosure as either 1150°C or 1250°C, depending on the sample) was maintained for a period varying from 2 to 30 minutes before the pistons were removed and cooled. After densification, the films were sectioned with a diamond saw and polished to a 1 μm surface finish. Cross-sectional analysis was then performed using a Hitachi S3500N scanning electron microscope.

[0060] Exemplary temperatures, times, and pressures are described above, but it is contemplated that, depending on the material, the precursor powder can be heated to a temperature between 500° C. and 1300° C. and pressurized between 1 MPa and 50 MPa.

[0061] <Cross-sectional analysis> Figure 2 shows the cross-sections of three LLZO films densified on Ni foils at different temperatures and forging times (images a), b), and c). All three samples demonstrate close LLZO / Ni adhesion, resulting in relatively uniform LLZO films with thicknesses of approximately 80 μm. The sample densified at 1150 °C for 20 min (image a) has the most uniform cross-section compared to the sample densified at 1250 °C for 5 min (image b) and the sample densified at 1250 °C for 2 min (image c). However, all three samples exhibit low porosity (<2%). Even with the shortest sinter-forging time (2 min), a small amount of pores is observed, suggesting that the application of pressure and the lack of lateral constraints allows for very rapid pore closure. Although the densities of the films are relatively similar, the microstructure is very uniform for the 20-minute sinter-forged film (Figure 2, image a), whereas for the sinter-forged films sintered for less than 5 minutes (i.e., images b and c) in Figure 2), regions of intergranular fracture are evident in the microstructure. These regions likely result from the fracture and removal of individual grains during sectioning. This suggests that the longer the sinter-forged time, the stronger the intergranular bonding, even though the density does not change significantly with time. Therefore, these parameters may be optimized to achieve the best combination of microstructure and manufacturing time.

[0062] <Continuous processing> In addition to the examples described above, the apparatus 10 can be used in a roll-to-roll process, a continuous manufacturing process in which materials, structures, or devices are printed, coated, or patterned onto or embedded within a roll of flexible substrate, as described in the aforementioned publication, U.S. Patent Application Publication No. 2017 / 0222254. Note that the publication describes a segmented, cellular structure in which ceramic thin film segments are disposed within a flexible matrix, such as a polymeric material. In such cases, each structure can be considered a separate thin film that collectively forms a sheet. Note also that all segmented portions are relatively flat, coin- or chip-like segments, with the thickness dimension of the segment being smaller than other dimensions of the segment, such as width or length (see, for example, FIG. 1a). This structure, with such an aspect ratio of the segments, can ensure relatively stable heat transfer in the powder layer during sintering and minimal gradients in the thickness direction of the thin film, while also enhancing the flexibility of the resulting sheet.

[0063] It is therefore contemplated that the apparatus 10 may include a transport mechanism or advancing device for advancing the precursor powder and substrate relative to the sinter forging region when the pressing and heating operations are not in progress. This advancing may involve moving the substrate in a direction generally along a plane perpendicular to the pressing direction, although this movement need not be precisely along a plane, as the substrate, precursor powder, and / or sintered thin film may sag to some degree outside of this region.

[0064] To form a continuous length of thin film from the precursor powder, the method may include repeatedly applying heat and pressure to the precursor powder to form a thin film, removing pressure from the thin film, and advancing the precursor powder and substrate to introduce the still-unsintered precursor powder into the sinter-forging zone. Such advancement may be less than the entire length of the sinter-forging zone, meaning that rather than advancing the substrate and powder / film the entire length of the sinter-forging zone, a length segment already pressurized and heated in a first cycle may be repressurized and heated in a second cycle. Among other things, this can help reduce the amount of sintering variation across the length of the resulting film and avoid the possibility of under-sintered regions along the length. In this manner, a continuous length of substrate having a length exceeding the maximum dimension of the sinter-forging zone and having one or more films formed thereon can be produced by repeated sinter-forging operations.

[0065] In one embodiment, a continuous length of substrate having a plurality of spaced-apart sintered films formed thereon can be produced by repeated sinter-forging operations. The spaces between each of the plurality of spaced-apart sintered films on the substrate can then be filled by depositing a flexible material between the spaced-apart sintered films. The flexible material can include a polymeric material selected from the group consisting of polyolefins, polystyrene, divinylbenzene, ethylene vinyl acetate polymers and copolymers, silicone polymers, styrene-divinylbenzene copolymers, and blends and mixtures thereof. The flexible material can include polypropylene or polyethylene.

[0066] The separate sintered films may each comprise a solid electrolyte material which may be any combination of garnet, perovskite, NaSICON, or LiSICON phase oxide or phosphate materials. w A x M2Re 3-y O z The solid electrolyte material may comprise a ceramic material having the chemical formula: w is 5 to 7.5, A is selected from B, Al, Ga, In, Zn, Cd, Y, Sc, Mg, Ca, Sr, Ba, and any combination thereof; x is 0 to 2, M is selected from Zr, Hf, Nb, Ta, Mo, W, Sn, Ge, Si, Sb, Se, Te, and any combination thereof; Re is selected from the group consisting of lanthanides, actinides, and any combination thereof; y is between 0 and 0.75; z is 10.875 to 13.125, The ceramic material has a garnet-type or garnet-like crystal structure. In one embodiment of the ceramic material, M is a combination of Zr and Ta. In one embodiment of the ceramic material, M is Zr, A is Al, and x is not 0. In one embodiment of the ceramic material, M is Zr, A is Ga, and x is not 0.

[0067] The separate sintered films may each include a sulfide-based solid electrolyte material containing at least lithium, sulfur, and phosphorus. The sulfide-based solid electrolyte material may be Li7P3S 11 , Li7PS6, Li4P2S6, Li3PS6, Li3PS4, Li2P2S6, Li 10 GeP2S 12 (LGPS), and Li 7-x PS 6-x Cl x , Li 7-x PS 6-x Br x and Li 7-x PS 6-x I x (wherein 0≦x≦2).

[0068] The spaced apart sintered films may each comprise a lithium host material selected from the group consisting of (i) lithium metal oxides, where the metal is one or more of aluminum, cobalt, iron, manganese, nickel, and vanadium, and (ii) lithium-containing phosphates having the general chemical formula of LiMPO4, where M is one or more of cobalt, iron, manganese, and nickel. If desired, the substrate can then be removed from the plurality of spaced apart sintered films embedded in the deposited flexible material.

[0069] In some embodiments of the method, the precursor powder comprises a binder, which may be selected from the group consisting of polyethylene oxide, polyvinylpyrrolidone, polyvinyl ether, polytetrafluoroethylene, polyacrylate, polyvinyl chloride, polyacrylonitrile, polyvinylpyridine, styrene butadiene rubber, acrylonitrile butadiene rubber, polyethylene, polypropylene, ethylene propylene diene terpolymer, cellulose, carboxymethyl cellulose, starch, hydroxypropyl cellulose, and mixtures thereof.

[0070] In some embodiments of the method, the separated sintered film has a thickness of 1 nm to 500 μm. In some embodiments of the method, the separated sintered film has a thickness of 1 nm to 100 μm. In some embodiments of the method, the substrate has a thickness of 1 nm to 100 μm.

[0071] In some embodiments of the method, the substrate comprises a metallic material selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, alloy steel, carbon steel, stainless steel, nickel-based superalloy, cobalt-based superalloy, copper, aluminum, iron, or mixtures thereof.

[0072] In some embodiments of the method, the substrate comprises a bimetal having a first layer comprising a first metallic material and a second layer comprising a second metallic material. The first metallic material can be selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, nickel-based superalloys, cobalt-based superalloys, copper, or mixtures thereof, and the second material is selected from the group consisting of aluminum, nickel, alloy steel, carbon steel, stainless steel, nickel-based superalloys, or mixtures thereof. In some embodiments of the method, the first metallic material comprises nickel and the second material comprises stainless steel. In some embodiments of the method, the first layer has a thickness of 1 nm to 100 μm, and the second layer has a thickness of 1 nm to 100 μm.

[0073] In some embodiments of the method, a layer of graphite particles is disposed between the substrate and the precursor powder. The layer of graphite particles can have a thickness of 1 μm to 10 μm.

[0074] Referring to FIG. 3, an array 34g, 34h, 34i of spaced apart sintered films embedded in a flexible material 38 can be formed by providing a plurality of the above-described apparatuses 10 (labeled 10a, 10b, and 10c in FIG. 3) arranged in a line, and then advancing spaced apart samples 34a, 34b, and 34c of precursor powder and substrate 16 in a direction A through the sinter-forging region of each apparatus 10a, 10b, and 10c, to create a line of spaced apart sintered films 34d, 34e, and 34f formed on the substrate 16 by repeated sinter-forging operations, the lines of spaced apart sintered films 34d, 34e, and 34f being perpendicular to the direction A of advancement of the substrate 16. The spaces between each of the plurality of spaced-apart sintered films 34d, 34e, 34f formed on the substrate 16 can be filled by depositing flexible material 38 between the spaced-apart sintered films 34d, 34e, 34f using a material dispenser 37 to form arrays 34g, 34h, 34i of the plurality of spaced-apart sintered films embedded in the flexible material 38. The apparatus of FIG. 3 forms an array of spaced-apart sintered films with 3 rows and N columns when the substrate 16 having the spaced-apart sintered films 34d, 34e, 34f advances through the material dispenser N times. It will be appreciated that arrays of different sizes can be made by selecting the number of apparatuses 10 described above and the number of times that different columns of spaced-apart sintered films 34d, 34e, 34f advance through the material dispenser 37 to deposit flexible material 38.

[0075] It is believed that such roll-to-roll or continuous length manufacturing techniques can be used to produce arrays of spaced apart sintered membranes that can be cut to the lengths required for battery fabrication.

[0076] Therefore, in summary, a system and method for sinter-forging to produce sintered thin films has been proposed. The system, which combines rapid induction heating and roll-to-roll processing, enables sinter-forging in large-scale continuous manufacturing. The design was demonstrated using LLZO ceramics slurry-cast on Ni foil substrates. It was demonstrated that dense (>98%) thin films (<100 μm) with ceramic / substrate adhesion can be produced in a relatively short time. The system can be used for the scalable production of a wide variety of materials, from structural metals to functional semiconductors.

[0077] Although the present invention has been described in considerable detail with reference to specific embodiments, it will be apparent to those skilled in the art that the present invention may be practiced in alternative embodiments to those described herein, and the embodiments described herein are presented for purposes of illustration and not limitation of the present invention. Accordingly, the scope of the appended claims should not be limited to the description of the embodiments contained herein.

[0078] <References> [1] ZZ Fang, ed., Sintering of Advanced Materials, in: Sinter. Adv. Mater., Woodhead Publishing, 2010: p. iv. doi:10.1016 / B978-1-84569-562-0.50019-4. [2] R. Raj, M. Cologna, JSC Francis, Influence of Externally Imposed and Internally Generated Electrical Fields on Grain Growth, Diffusional Creep, Sintering and Related Phenomena in Ceramics, J. Am. Ceram. Soc. 94 (2011) 1941-1965. doi:10.1111 / j.1551-2916.2011.04652.x. [3] F.F. Lange, B.I. Davis, E. Wright, Processing-Related Fracture Origins: IV, Elimination of Voids Produced by Organic Inclusions, J. Am. Ceram. Soc. 69 (1986) 66-69. doi:10.1111 / j.1151-2916.1986.tb04696.x. [4] G. Skandan, H. Hahn, B.H. Kear, M. Roddy, W.R. Cannon, The effect of applied stress on densification of nanostructured zirconia during sinter-forging, Mater. Lett. 20 (1994) 305-309. doi:10.1016 / 0167-577X(94)90035-3. [5] K.R. Venkatachari, R. Raj, Enhancement of Strength through Sinter Forging, J. Am. Ceram. Soc. 70 (1987) 514-520. doi:10.1111 / j.1151-2916.1987.tb05686.x. [6] K.R. Venkatachari, R. Raj, Shear Deformation and Densification of Powder Compacts, J. Am. Ceram. Soc. 69 (1986) 499-506. doi:10.1111 / j.1151-2916.1986.tb07452.x. [7] E. Rangasamy, J. Wolfenstine, J. Sakamoto, The role of Al and Li concentration on the formation of cubic garnet solid electrolyte of nominal composition Li7La3Zr2O 12, Solid State Ion. 206 (2012) 28-32. doi:10.1016 / j.ssi.2011.10.022.

[0079] The citation of any document shall not be construed as an admission that it is prior art with respect to the present invention.

Claims

1. A method for forming a film as a sintered film by sinter-forging a precursor powder, comprising: supporting the precursor powder on a substrate; simultaneously applying heat and pressure to the precursor powder in a pressure direction parallel to the thickness of the film to sinter and densify the precursor powder to form the film within a sinter-forged region, wherein the sinter-forged region is free of lateral constraints in a plane perpendicular to the pressure direction; A method comprising:

2. 10. The method of claim 1, wherein the simultaneous application of heat and pressure causes deformation and pressure-assisted sintering of the precursor powder to produce a dense ceramic body.

3. The method of claim 1 , wherein frictional stress between the film and the substrate creates a hydrostatic stress state within the film during sintering.

4. The method of claim 1 , wherein a combination of applied pressure and frictional pressure stresses creates a hydrostatic stress state within the membrane during sintering.

5. The method of claim 1 , wherein the substrate is movable in a direction substantially along a plane perpendicular to the direction of pressure application when the precursor powder is not simultaneously heated and pressure applied.

6. (a) simultaneously applying heat and pressure to the precursor powder to form the film; (b) removing pressure from the membrane; (c) repeatedly advancing the precursor powder and the substrate to introduce the as-yet-unsintered precursor powder into the sinter-forging region; As a result, a continuous length of the substrate having a length exceeding the maximum dimension of the sinter-forged region has one or more films formed by repeated sinter-forging. The method of claim 5.

7. the step of simultaneously applying heat and pressure to the precursor powder is performed by a piston; The method of claim 1 , wherein the piston is part of a device that articulates the piston into and out of the sinter forging area.

8. 8. The method of claim 7, further comprising the step of heating the piston by induction heating using an induction coil surrounding the piston.

9. The method of claim 7 , wherein the piston comprises graphite.

10. The method of claim 1 further comprising the step of heating the substrate by induction heating using an induction coil surrounding the substrate.

11. The method of claim 7 , further comprising the step of applying a release layer to prevent adhesion between the piston and the membrane before the step of simultaneously applying heat and pressure to the precursor powder.

12. The method of claim 1 further comprising the step of providing an environmental gas around the sinter forging area.

13. The method of claim 1 , wherein the precursor powder is part of a powder slurry.

14. The method of claim 13 , wherein the precursor powder includes a binder.

15. 15. The method of claim 14, wherein the binder is selected from the group consisting of polyvinylidene fluoride, poly(methyl methacrylate), poly(vinyl acetate), polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl ether, polytetrafluoroethylene, polyacrylate, polyvinyl chloride, polyacrylonitrile, polyvinylpyridine, styrene butadiene rubber, acrylonitrile butadiene rubber, polyethylene, polypropylene, ethylene propylene diene terpolymer, cellulose, carboxymethyl cellulose, starch, hydroxypropyl cellulose, and mixtures thereof.

16. The method of claim 1 , wherein the precursor powder is a metal or ceramic material.

17. the sintered film comprises a solid electrolyte material which may be any combination of oxide or phosphate materials in the garnet, perovskite, NaSiCON, or LiSiCON phases; The method of claim 1.

18. The sintered film is Li ｗ A ｘ M ２ Re ３－ｙ O ｚ and a solid electrolyte material comprising a ceramic material having a chemical formula of: w is 5 to 7.5; A is selected from B, Al, Ga, In, Zn, Cd, Y, Sc, Mg, Ca, Sr, Ba, and any combination thereof; x is 0 to 2; M is selected from Zr, Hf, Nb, Ta, Mo, W, Sn, Ge, Si, Sb, Se, Te, and any combination thereof; Re is selected from the group consisting of a lanthanide element, an actinide element, and any combination thereof; y is 0 to 0.75; z is 10.875 to 13.125; the ceramic material has a garnet-type or garnet-like crystal structure; The method of claim 1.

19. The sintered film contains a sulfide-based solid electrolyte material containing at least lithium, sulfur, and phosphorus. The method of claim 1.

20. The sulfide-based solid electrolyte material is Li ７ P ３ S １１ , Li ７ P.S. ６ , Li ４ P ２ S ６ , Li ３ P.S. ６ , Li ３ P.S. ４ , Li ２ P ２ S ６ , Li １０ GeP ２ S １２ (LGPS), and Li ７－ｘ P.S. ６－ｘ Cl ｘ , Li ７－ｘ P.S. ６－ｘ Br ｘ and Li ７－ｘ P.S. ６－ｘ I ｘ (wherein 0≦x≦2), 20. The method of claim 19.

21. The sintered film comprises a lithium host material. The method of claim 1.

22. The sintered film comprises: (i) a lithium metal oxide, wherein the metal is one or more of aluminum, cobalt, iron, manganese, nickel, and vanadium; and (ii) LiMPO ４ wherein M is one or more of cobalt, iron, manganese, and nickel; The method of claim 1.

23. 10. The method of claim 1, wherein the step of simultaneously heating and pressurizing the precursor powder comprises heating at a temperature between 30°C and 2000°C and pressing at a pressure between 1 MPa and 500 MPa.

24. 10. The method of claim 1, wherein the step of simultaneously heating and pressing the precursor powder comprises heating at a temperature between 500°C and 1300°C and pressing at a pressure between 1 MPa and 50 MPa.

25. The method of claim 1 , wherein the sintered film has a relative density of greater than 90% for a sinter-forging time of less than 90 minutes.

26. 10. The method of claim 1, wherein the sintered film has a relative density of greater than 98% with a sinter-forging time of less than 5 minutes.

27. The method of claim 1 , wherein the sintered film has a thickness of 1 nm to 500 μm.

28. The method of claim 1 , wherein the sintered film has a thickness of 1 nm to 100 μm.

29. The method of claim 1 , wherein the substrate has a thickness of 1 nm to 100 μm.

30. 10. The method of claim 1, wherein the substrate comprises a metallic material selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, alloy steel, carbon steel, stainless steel, nickel-based superalloy, cobalt-based superalloy, copper, aluminum, iron, or mixtures thereof.

31. The method of claim 1 , wherein the substrate comprises a bimetal having a first layer comprising a first metallic material and a second layer comprising a second metallic material.

32. the first metallic material is selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, a nickel-based superalloy, a cobalt-based superalloy, copper, or a mixture thereof; the second metallic material is selected from the group consisting of aluminum, nickel, alloy steel, carbon steel, stainless steel, nickel-based superalloy, or mixtures thereof; 32. The method of claim 31 .

33. the first metallic material includes nickel; the second metallic material comprises stainless steel; 33. The method of claim 32.

34. 33. The method of claim 32, wherein the first layer has a thickness of 1 nm to 100 μm and the second layer has a thickness of 1 nm to 100 μm.

35. The method of claim 1 , wherein a layer of graphite particles is disposed between the substrate and the precursor powder.

36. 36. The method of claim 35, wherein the graphite particle layer has a thickness of 1 μm to 10 μm.

37. An apparatus for forming a film by sinter-forging a precursor powder onto a substrate, comprising: a load frame having a sinter-forging area defined therein for receiving the precursor powder; a piston capable of withstanding induction heating, operable by the load frame in a pressure direction, and simultaneously applying heat and pressure to the precursor powder received in the sinter-forging area; a set of induction coils concentric with the piston so that the piston can be heated by high frequency induction; Equipped with the sinter-forging region is located along a plane perpendicular to the pressing direction, There is no lateral constraint in the sinter forged region; Device.

38. 38. The apparatus of claim 37, wherein the simultaneous application of heat and pressure causes deformation and pressure-assisted sintering of the precursor powder to produce a dense ceramic body.

39. 38. The apparatus of claim 37, wherein frictional stress between the membrane and the substrate creates a hydrostatic stress state within the membrane during sintering.

40. 38. The apparatus of claim 37, wherein a combination of applied pressure and frictional pressure stresses creates a hydrostatic stress state within the membrane during sintering.

41. a non-conductive shroud surrounding the piston; the non-conductive shroud defines a hollow cavity between the piston and the non-conductive shroud; 38. The apparatus of claim 37, wherein the hollow cavity opens into the sinter forging area.

42. a gas inlet in fluid communication with the hollow cavity; 42. The apparatus of claim 41, wherein the gas inlet is configured to supply gas flowing therethrough into the hollow cavity, past the piston, through the hollow cavity, and into an ambient environment in the sinter forging area.

43. 38. The apparatus of claim 37, further comprising a transport mechanism for advancing the precursor powder and the substrate through the sinter forging region.

44. 38. The apparatus of claim 37, further comprising a system for controlling the temperature of the substrate comprising one or more of a thermocouple, a temperature controller, and a coolant circulator.

45. 38. The apparatus of claim 37, wherein the piston comprises graphite.

46. 38. The apparatus of claim 37, wherein the piston can be heated to a temperature of 30°C to 2000°C by the set of induction coils and a pressure of 1 MPa to 500 MPa can be applied by the load frame within the sinter-forging area.

47. 38. The apparatus of claim 37, wherein the piston can be heated to a temperature of 500°C to 1300°C by the set of induction coils and a pressure of 1 MPa to 50 MPa can be applied by the load frame within the sinter-forging area.

48. A method for forming an electrochemical device comprising an array of spaced apart sintered films by sinter-forging a precursor powder onto a substrate to form a film as a sintered film, comprising: supporting spaced portions of the precursor powder on the substrate; simultaneously heating and applying pressure to the separated portions of the precursor powder in a pressure direction parallel to a thickness of the separated portions of the precursor powder to form the separated sintered films on the substrate; depositing a flexible material on the substrate between the spaced apart sintered films; Including, each said spaced apart sintered membrane being formed in a separate sinter forging zone; The method wherein each of the sinter forged regions is free of lateral constraint in a plane perpendicular to the pressing direction.

49. The precursor powder is a ceramic material.

49. The method of claim 48.

50. 49. The method of claim 48, wherein the simultaneous application of heat and pressure causes deformation and pressure-assisted sintering of the precursor powder to produce a dense ceramic body.

51. 49. The method of claim 48, wherein frictional stress between the film and the substrate creates a hydrostatic stress state in the film during sintering.

52. 49. The method of claim 48, wherein a combination of applied pressure and frictional pressure stresses creates a hydrostatic stress state in the membrane during sintering.

53. 49. The method of claim 48, wherein the substrate is movable in a direction generally along the plane perpendicular to the direction of the application of pressure when the spaced apart portions of the precursor powder are not simultaneously heated and pressurized.

54. (a) simultaneously applying heat and pressure to the spaced apart portions of the precursor powder to form the spaced apart sintered films; (b) removing pressure from the spaced apart sintered membranes; (c) advancing the substrate to introduce as-yet-unsintered, discrete portions of the precursor powder into the sinter forging zone; (d) depositing a flexible material between the spaced apart sintered films on the substrate; whereby an array of continuous lengths of spaced apart sintered membranes surrounded by said flexible material is formed by repeated sinter-forging.

54. The method of claim 53.

55. the spaced apart sintered films comprise a solid electrolyte material which may be any combination of oxide or phosphate materials in the garnet, perovskite, NaSiCON, or LiSiCON phases; 49. The method of claim 48.

56. The separated sintered film is Li ｗ A ｘ M ２ Re ３－ｙ O ｚ and a solid electrolyte material comprising a ceramic material having a chemical formula of: w is 5 to 7.5; A is selected from B, Al, Ga, In, Zn, Cd, Y, Sc, Mg, Ca, Sr, Ba, and any combination thereof; x is 0 to 2; M is selected from Zr, Hf, Nb, Ta, Mo, W, Sn, Ge, Si, Sb, Se, Te, and any combination thereof; Re is selected from the group consisting of a lanthanide element, an actinide element, and any combination thereof; y is 0 to 0.75; z is 10.875 to 13.125; the ceramic material has a garnet-type or garnet-like crystal structure; 49. The method of claim 48.

57. The separated sintered film contains a sulfide-based solid electrolyte material containing at least lithium, sulfur, and phosphorus.

49. The method of claim 48.

58. The sulfide-based solid electrolyte material is Li ７ P ３ S １１ , Li ７ P.S. ６ , Li ４ P ２ S ６ , Li ３ P.S. ６ , Li ３ P.S. ４ , Li ２ P ２ S ６ , Li １０ GeP ２ S １２ (LGPS), and Li ７－ｘ P.S. ６－ｘ Cl ｘ , Li ７－ｘ P.S. ６－ｘ Br ｘ and Li ７－ｘ P.S. ６－ｘ I ｘ (wherein 0≦x≦2), 58. The method of claim 57.

59. the spaced apart sintered films comprise a lithium host material; 49. The method of claim 48.

60. The spaced apart sintered films comprise: (i) a lithium metal oxide, wherein the metal is one or more of aluminum, cobalt, iron, manganese, nickel, and vanadium; and (ii) LiMPO ４ wherein M is one or more of cobalt, iron, manganese, and nickel; 49. The method of claim 48.

61. the flexible material comprises a polymeric material; 49. The method of claim 48.

62. the flexible material comprises a polymeric material selected from the group consisting of polyolefins, polystyrene, divinylbenzene, ethylene vinyl acetate polymers and copolymers, silicone polymers, styrene-divinylbenzene copolymers, and blends and mixtures thereof; 49. The method of claim 48.

63. 49. The method of claim 48, wherein the precursor powder includes a binder.

64. 64. The method of claim 63, wherein the binder is selected from the group consisting of polyvinylidene fluoride, poly(methyl methacrylate), poly(vinyl acetate), polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl ether, polytetrafluoroethylene, polyacrylate, polyvinyl chloride, polyacrylonitrile, polyvinylpyridine, styrene butadiene rubber, acrylonitrile butadiene rubber, polyethylene, polypropylene, ethylene propylene diene terpolymer, cellulose, carboxymethyl cellulose, starch, hydroxypropyl cellulose, and mixtures thereof.

65. 49. The method of claim 48, wherein the spaced apart sintered films have a thickness of 1 nm to 500 μm.

66. 49. The method of claim 48, wherein the spaced apart sintered films have a thickness of 1 nm to 100 μm.

67. 49. The method of claim 48, wherein the substrate has a thickness of between 1 nm and 100 μm.

68. 49. The method of claim 48, wherein the substrate comprises a metallic material selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, alloy steel, carbon steel, stainless steel, nickel-based superalloy, cobalt-based superalloy, copper, aluminum, iron, or mixtures thereof.

69. 49. The method of claim 48, wherein the substrate comprises a bimetal having a first layer comprising a first metallic material and a second layer comprising a second metallic material.

70. the first metallic material is selected from the group consisting of nickel, molybdenum, titanium, zirconium, tantalum, a nickel-based superalloy, a cobalt-based superalloy, copper, or a mixture thereof; the second metallic material is selected from the group consisting of aluminum, nickel, alloy steel, carbon steel, stainless steel, nickel-based superalloy, or mixtures thereof; 70. The method of claim 69.

71. the first metallic material includes nickel; the second metallic material comprises stainless steel; 70. The method of claim 69.

72. 70. The method of claim 69, wherein the first layer has a thickness of 1 nm to 100 μm and the second layer has a thickness of 1 nm to 100 μm.

73. 49. The method of claim 48, wherein a layer of graphite particles is disposed between the substrate and the precursor powder.

74. 74. The method of claim 73, wherein the graphite particle layer has a thickness of 1 μm to 10 μm.

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