Rapid thermal processing method and apparatus

Abstract

A method and apparatus for manufacturing separators for solid-state lithium metal batteries uses rapid thermal processing. Aspects include high temperature sintering. In a batch process, the temperature, heating time, and proximity of a heating element to the material being sintered are combined to provide a separator with desired physical properties, including porosity.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 309,985, entitled "RAPID THERMAL PROCESSING METHODS AND APPARATUS," filed February 14, 2022, and U.S. Provisional Patent Application No. 63 / 314,296, entitled "RAPID THERMAL PROCESSING METHODS AND APPARATUS," filed February 25, 2022, both of which are incorporated herein by reference in their entirety for all purposes. This application is also related to International Application No. PCT / US2022 / 019641, entitled RAPID CERAMIC PROCESSING TECHNIQUES AND EQUIPMENT, filed March 9, 2022, and U.S. Patent Application No. 17 / 905,822, entitled RAPID CERAMIC PROCESSING TECHNIQUES AND EQUIPMENT, filed September 8, 2022, both of which are incorporated herein by reference in their entirety for all purposes.

[0002] (Field) This application relates to rapid thermal processing methods and apparatus for producing solid electrolytes in batch processing of rechargeable batteries, particularly solid-state lithium metal batteries, and more particularly, lithium metal batteries, such as, but not limited to, lithium lanthanum titanate, lithium aluminum titanium phosphate (LATP), lithium aluminum germanium phosphate (LAGP), or lithium loaded garnet oxide. In some instances, these ceramics are deposited as a layer on top of a metal layer. These two layers form a bilayer. [Background technology]

[0003] (background) Solid-state lithium metal batteries include an anode, a cathode, and a solid electrolyte separator. The solid electrolyte separator must conduct lithium ions between the anode and the cathode. It would be desirable to have a separator that has these properties and can be efficiently manufactured.

[0004] Certain methods of sintering lithium-loaded garnets (crystalline lithium lanthanum zirconium oxide, or "LLZO" herein), such as batch sintering of LLZO, are described, for example, in U.S. Pat. Nos. 10,563,918 B2 or 10,840,544 B2. High-throughput continuous sintering of certain ceramics is also disclosed in U.S. Pat. No. 10,766,165 B2; and PCT Patent Application WO 2017 / 003980 A1. Summary of the Invention [Means for solving the problem]

[0005] (overview) The following description aspects describe methods and apparatus employing rapid thermal processing (RTP) to produce separators for solid-state lithium metal batteries. In some aspects, the method includes sintering materials at high temperatures for short periods of time to produce separators in a batch process. In some embodiments, the temperature can range from about 900° C. to about 2,000° C. In some embodiments, the time can range from about 5 seconds to about 30 minutes. In some embodiments, the heating element can be at a distance of about 1 millimeter to about 2,000 millimeters from the material to be sintered. In some embodiments, the heating element can be close enough to the material to be sintered that the respective surfaces of the heating element and the material to be sintered do not allow contact with one or both of the heating element and the material to be sintered. In some embodiments, the material to be sintered can include LATP, LAGP, or LLZO. In some aspects, the apparatus includes one or more heating elements in sufficient proximity to the material to be sintered. In some embodiments, the heating element can include different forms of silicon carbide, molybdenum, or carbon.

[0006] Some embodiments relate to a sintered article made according to one of the methods disclosed herein. Other embodiments relate to a rechargeable battery made according to one of the methods disclosed herein. [Brief description of the drawings]

[0007] BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1] FIG. 1 is a schematic diagram of an apparatus according to one embodiment.

[0008] [Diagram 2] FIG. 2 is a schematic diagram of an apparatus according to one embodiment.

[0009] [Diagram 3] FIG. 3 is a schematic diagram of an apparatus according to one embodiment.

[0010] [Figure 4A-4C] 4A-4C show thin films produced according to embodiments.

[0011] [Diagram 5] FIG. 5 is a schematic diagram of an apparatus according to one embodiment.

[0012] [Figure 6A-6C] 6A-6C are diagrams of a structure used to facilitate processing of a dual layer structure through a rapid thermal processor according to one embodiment.

[0013] [Figure 7A-7B] 7A and 7B are different views of a bilayer assembly being passed through a rapid thermal processor according to one embodiment.

[0014] [Figure 8] FIG. 8 is a schematic diagram of an apparatus according to one embodiment.

[0015] [Figure 9]FIG. 9 shows two thin films formed according to one embodiment.

[0016] [Figure 10] FIG. 10 shows cycling data for a bilayer battery including a thin film formed according to one embodiment.

[0017] [Figure 11] FIG. 11 shows cycling data for a multi-layer battery including a thin film formed according to one embodiment.

[0018] [Figure 12] FIG. 12 shows a thin film formed according to one embodiment.

[0019] [Figure 13] FIG. 13 shows a thin film formed according to one embodiment.

[0020] [Figure 14] FIG. 14 shows a cross section of a green film before heat treatment according to one embodiment.

[0021] [Figure 15] FIG. 15 shows a cross section of the green thin film of FIG. 14 after the heat treatment steps described herein.

[0022] [Figure 16] FIG. 16 shows an example of a thin film formed according to one embodiment.

[0023] [Figure 17] FIG. 17 shows an example of a thin film formed according to one embodiment.

[0024] [Figure 18] FIG. 18 shows an example of a thin film formed according to one embodiment.

[0025] [Figure 19] FIG. 19 illustrates one embodiment of a setter stack as disclosed herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] (Detailed Description) The following description will enable a person skilled in the art to make and use the disclosed subject matter and incorporate the subject matter into several applications. Various modifications and uses in different applications will be readily apparent to those skilled in the art. The general principles described herein can be applied to a wide range of embodiments. Thus, the present disclosure is not intended to be limited to the embodiments shown, but is intended to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0027] In the following detailed description, numerous specific details are set forth in order to provide a more thorough understanding of the disclosed structures and techniques. However, it will be apparent to those skilled in the art that the disclosed structures and techniques may be practiced without necessarily being limited to these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detailed diagram form, in order to avoid obscuring the present disclosure.

[0028] definition As used herein, the term "about" when used to modify a numerical value, e.g., about 15 weight percent (w / w%), refers to the applicable numerical value and, optionally, to a range of the applicable numerical value, including ±10% of the applicable numerical value. For example, about 15 w / w% includes 13.5 w / w%, 14 w / w%, 14.5 w / w%, 15.5 w / w%, 16 w / w%, or 16.5 w / w%, as well as 15 w / w%. For example, "about 75°C" includes 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, or 83°C, as well as 75°C.

[0029] As used herein, "selected from the group consisting of" refers to one member from the group, two or more members from the group, or a combination of members from the group. For example, members selected from the group consisting of A, B, and C can include A and B, A and C, B and C, and A, B and C, as well as A alone, B alone, or C alone.

[0030] As used herein, the phrase "electrochemical cell" or "battery cell" refers to a single cell including a positive electrode and a negative electrode, with ionic communication between the positive electrode and the negative electrode by an electrolyte, unless otherwise stated. In some embodiments, a battery or module includes multiple positive electrodes and / or multiple negative electrodes enclosed in a single container, e.g., a stack of electrochemical cells. A stack of electrochemical cells may also be referred to as a multi-layer cell. A symmetric cell may be a cell with two Li metal anodes separated by a solid electrolyte.

[0031] As used herein, the phrase "electrochemical stack" refers to one or more units, each unit including at least a negative electrode (e.g., Li, LiC 6 ), positive electrode (e.g., FeF 3 , NiF x (x is 2 or 3), Nickel Cobalt Aluminum Oxide (NCA), Lithium Iron Phosphate (LFP), LiNi x Mn y Co z O 2 , [NMC], or LiNi x Al y Co z O 2 [NCA], where x+y+z=1; and 0≦x≦1; 0≦y≦1; and 0≦z≦1, optionally in combination with a solid electrolyte or gel electrolyte, and a solid electrolyte (e.g., lithium-filled garnet (e.g., Li 7 La 3 Zr 2 O 12) as described herein). In some examples, there is an additional layer between the solid electrolyte and the positive electrode that includes a flexible electrolyte (e.g., gel electrolyte, gel polymer electrolyte). The electrochemical stack may include one of these aforementioned units. The electrochemical stack may include several of these aforementioned units arranged in electrical communication (e.g., serial or parallel electrical connection). In some examples, when the electrochemical stack includes multiple units, the units are layered or stacked in a column. In some examples, when the electrochemical stack includes several units, the units are layered or stacked in an array. In some examples, when the electrochemical stack includes several units, the stack is arranged such that one negative electrode current collector is shared by two or more positive electrodes. Alternatively, in some examples, when the electrochemical stack includes several units, the stack is arranged such that one positive electrode current collector is shared by two or more negative electrodes. Unless otherwise specified, an electrochemical stack includes a positive current collector, a solid electrolyte, and a negative electrode, and optionally an adhesion layer between the positive electrode and the solid electrolyte.

[0032] As used herein, the term "positive electrode" refers to a secondary battery that is charged with positive ions, e.g., Li + As used herein, the term "negative electrode" refers to the electrode toward which positive ions, e.g., Li, conduct, flow, or migrate during discharge of a secondary battery. + refers to the electrode through which Li ions flow or migrate. In a battery consisting of a Li metal electrode and an electrode containing a conversion, intercalation, or combination of conversion / intercalation chemistry (i.e., cathode active material), the electrode with the conversion, intercalation, or combination of conversion / intercalation chemistry is called the positive electrode. In some usages, a cathode is used in place of the positive electrode and an anode is used in place of the negative electrode. When a Li secondary battery is charged, Li ions flow into the positive electrode (e.g., NiF x, NMC, NCA) toward the negative electrode (e.g., Li metal). When a Li secondary battery is discharged, Li ions migrate from the negative electrode to the positive electrode.

[0033] As used herein, the phrase "positive terminal" refers to an electrical connection to a positive electrode. The positive terminal is sometimes called a positive current collector.

[0034] As used herein, the phrase "negative electrode terminal" refers to the electrical connection to the negative electrode. The negative electrode terminal is sometimes also called the negative electrode current collector.

[0035] As used herein, the phrase "cathode active material" refers to a material that can reversibly intercalate or react with lithium ions. Examples include LiMPO 4 (M=Fe, Ni, Co, Mn); Li x Ti y O z (wherein x is 0 to 8, y is 1 to 12, and z is 1 to 24); LiMn 2a Ni a O 4 (wherein a is 0 to 2); nickel cobalt aluminum oxide; LiNi x Mn y Co z O 2 (wherein x+y+z=1, 0≦x≦1, 0≦y≦1, and 0≦z≦1); and LiNi x Co y Al z O 2 where x+y+z=1, and 0≦x≦1, 0≦y≦1, and 0≦z≦1. In these formulas, x, y, and z are selected such that the formula is charge neutral.

[0036] As used herein, the phrase "solid cathode" refers to a cathode that does not contain a liquid phase electrolyte. As used herein, the terms "cathode" and "anode" refer to the electrodes of a battery. The cathode and anode are often referred to in the art as the positive and negative electrodes, respectively.

[0037] As used herein, the phrase "solid catholyte" or the term "catholyte" refers to an ionic conductor that is intimately mixed with or surrounded by the cathode (i.e., positive electrode) active material.

[0038] As used herein, the term "electrolyte" refers to a material that can pass ions, e.g., Li+, but cannot conduct electrons. For example, the ratio of ionic conductivity to electronic conductivity is at least 10 6 The electrolyte serves to electrically insulate the cathode and anode of a secondary battery while allowing the passage of ions, e.g., Li+, through the electrolyte.

[0039] As used herein, the phrase "solid electrolyte separator" is used interchangeably with the phrase "solid separator" and refers to a separator that is formed by dissolving atomic ions (e.g., Li + ) refers to a material that conducts electricity but does not conduct electrons. A solid electrolyte separator is a solid material suitable for electrically separating the positive and negative electrodes of a lithium secondary battery while also providing a conductive path for lithium ions. Examples of inorganic solid electrolytes include oxide electrolytes and sulfide electrolytes, which are further defined below. Non-limiting examples of sulfide electrolytes are also described, for example, in U.S. Patent Application Publication No. 9,172,114, issued October 27, 2015, and U.S. Patent Application Publication No. 2017-0162901 A1, published June 8, 2017. Non-limiting examples of oxide electrolytes are also described, for example, in U.S. Patent Application Publication No. 2015-0200420 A1, published July 16, 2015, and issued as U.S. Patent No. 9,806,372 on October 31, 2017. In some examples, the inorganic solid electrolyte also includes a polymer, referred to as a composite electrolyte. Composite electrolytes are described, for example, in U.S. Patent No. 9,666,870, the entire contents of which are incorporated herein by reference in their entireties for all purposes.

[0040] As used herein, the term "annealing" refers to annealing in a reducing atmosphere, e.g., dry air or argon, Ar / H 2 , and N 2 In the above, the term "annealing" refers to heating the material to, for example, 100°C to 1,400°C, or, for example, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, 900°C, 950°C, 1,000°C, 1,050°C, 1,100°C, 1,150°C, 1,200°C, 1,250°C, 1,300°C, 1,350°C, or 1,450°C. Some examples of annealing methods are described in U.S. Patent No. 9,966,630 B2, the entire contents of which are incorporated herein by reference for all purposes.

[0041] In some examples, the thin film is heated in an apparatus described herein or in a process described herein. In some examples, the thin film is heated to 1,000° C. In some examples, the thin film is heated to 1,010° C. In some examples, the thin film is heated to 1,020° C. In some examples, the thin film is heated to 1,030° C. In some examples, the thin film is heated to 1,040° C. In some examples, the thin film is heated to 1,050° C. In some examples, the thin film is heated to 1,060° C. In some examples, the thin film is heated to 1,070° C. In some examples, the thin film is heated to 1,080° C. In some examples, the thin film is heated to 1,090° C. In some examples, the thin film is heated to 1,100° C. In some examples, the thin film is heated to 1,110° C. In some examples, the thin film is heated to 1,120° C. In some examples, the thin film is heated to 1,130° C. In some examples, the thin film is heated to 1,140° C. In some examples, the film is heated to 1,150°C. In some examples, the film is heated to 1,160°C. In some examples, the film is heated to 1,170°C. In some examples, the film is heated to 1,180°C. In some examples, the film is heated to 1,190°C. In some examples, the film is heated to 1,200°C. In some examples, the film is heated to 1,210°C. In some examples, the film is heated to 1,220°C. In some examples, the film is heated to 1,230°C. In some examples, the film is heated to 1,240°C. In some examples, the film is heated to 1,250°C.

[0042] As used herein, "separator" and "Li + The terms "ionically conductive separator" and "ionically conductive separator" are used interchangeably and unless expressly specified otherwise, the separator is + An abbreviation for ion-conductive separator.

[0043] Unless expressly specified to the contrary, the separators used herein are stable in contact with lithium metal. Stability in contact with lithium metal can be demonstrated by the absence of significant exothermic reaction when lithium metal and the separator material are in intimate contact and heated to at least 200° C. in a differential scanning calorimeter. In one embodiment, the stability can be kinetic stability to construct a solid electrolyte interface (SEI) that increases the ASR to greater than about 100. In one embodiment, the stability can be kinetic stability to construct an SEI that increases the ASR to greater than about 1,000. In a different embodiment, the stability can be kinetic stability to construct an SEI that increases the ASR to a range of about 100 to about 1,000. In one embodiment, the stability can be defined in terms of the initial ASR when contacted with lithium and the change in ASR after prolonged contact with lithium. In one embodiment, the prolonged contact can be exposure to lithium at a temperature of about 60° C. for about 30 days.

[0044] As used herein, the phrase "thickness" or "thin film thickness" refers to the distance between the top and bottom surfaces or between the top and bottom surfaces, or the median of the measured distances. As used herein, the top and bottom surfaces or top and bottom surfaces refer to the surfaces having the largest geometric surface area.

[0045] As used herein, "thin" means, when qualifying as a solid electrolyte, a thickness dimension less than 200 μm, sometimes less than 100 μm, in some cases 0.1 to 60 μm, and in other cases from about 10 nm to about 100 μm; in other cases, a thickness of about 1 μm, 10 μm, or 50 μm.

[0046] As used herein, the term "lithium-filled garnet" refers to an oxide characterized by a crystal structure associated with the garnet crystal structure. U.S. Patent Application Publication No. 2015 / 0099190, filed on October 7, 2014, as Serial No. 14 / 509,029 and published on April 9, 2015, is hereby incorporated by reference in its entirety for all purposes. This application describes a Li-filled garnet solid electrolyte used in solid lithium rechargeable batteries.

[0047] Unless otherwise stated, the lithium-filled garnet has the formula Li A La B M’ C M’’ D Zr E O F 、Li A La B M’ C M’’ D Ta E O F 、or Li A La B M’ C M’’ D Nb E O F (where 4 < A < 8.5, 1.5 < B < 4, 0 ≤ C ≤ 2, 0 ≤ D ≤ 2; 0 ≤ E ≤ 2.5, 10 < F < 13, and M’’ and M’’ are each independently, in each case, selected from Al, Mo, W, Ga, Nb, Sb, Ca, Ba, Sr, Ce, Hf, Rb, or Ta), or Li a La b Zr c Al d Me’’ e O f (where 5 < a < 7.7; 2 < b < 4; 0 ≤ c ≤ 2.5; 0 ≤ d ≤ 2; 0 ≤ e ≤ 2, 10 < f < 13, and Me’’ is a metal selected from Nb, Ta, V, W, Mo, Ga, or Sb) and includes compounds having such.

[0048] The lithium-filled garnet also has the formula Li A LaB M' C M'' D Zr E O F , Li A La B M' C M'' D Ta E O F , or Li A La B M' C M'' D Nb E O F (where 4 < A < 8.5, 1.5 < B < 4, 0 ≤ C ≤ 2, 0 ≤ D ≤ 2; 0 ≤ E < 3, 10 < F < 13, and M' and M'' are each independently, in each case, selected from Ga, Al, Mo, W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, Rb, or Ta), or Li a La b Zr c Al d Me'' e O f (where 5 < a < 8.5; 2 < b < 4; 0 < c ≤ 2.5; 0 ≤ d < 2; 0 ≤ e < 2, and 10 < f < 13, and Me'' is a metal selected from Ga, Nb, Ta, V, W, Mo, or Sb) can be a composition. As used herein, lithium-filled garnet and garnet generally, but not limited to, Li 7.0 La 3 (Zr t1 + Nb t2 + Ta t3 )O 12 + 0.35Al 12 O 3 (where the La:(Zr / Nb / Ta) ratio is 3:2 such that (t1 + t2 + t3 = 2)) is included. Also, the garnet used herein generally, but not limited to, Li x La 3 Zr 2 O F + yAl 2 O 3where x ranges from 5.5 to 9; y ranges from 0.05 to 1. In these examples, the subscripts x, y, and F are selected such that the garnet is charge neutral. In some examples, x is 7 and y is 1.0. In some examples, x is 5 and y is 1.0. In some examples, x is 6 and y is 1.0. In some examples, x is 8 and y is 1.0. In some examples, x is 9 and y is 1.0. In some examples, x is 7 and y is 0.35. In some examples, x is 5 and y is 0.35. In some examples, x is 6 and y is 0.35. In some examples, x is 8 and y is 0.35. In some examples, x is 9 and y is 0.35. In some examples, x is 7 and y is 0.7. In some examples, x is 5 and y is 0.7. In some examples, x is 6 and y is 0.7. In some examples, x is 8 and y is 0.7. In some examples, x is 9 and y is 0.7. In some examples, x is 7 and y is 0.75. In some examples, x is 5 and y is 0.75. In some examples, x is 6 and y is 0.75. In some examples, x is 8 and y is 0.75. In some examples, x is 9 and y is 0.75. In some examples, x is 7 and y is 0.8. In some examples, x is 5 and y is 0.8. In some examples, x is 6 and y is 0.8. In some examples, x is 8 and y is 0.8. In some examples, x is 9 and y is 0.8. In some examples, x is 7 and y is 0.5. In some examples, x is 5 and y is 0.5. In some examples, x is 6 and y is 0.5. In some examples, x is 8 and y is 0.5. In some examples, x is 9 and y is 0.5. In some examples, x is 7 and y is 0.4. In some examples, x is 5 and y is 0.4. In some examples, x is 6 and y is 0.4. In some examples, x is 8 and y is 0.4. In some examples, x is 9 and y is 0.4. In some examples, x is 7 and y is 0.3.In some examples, x is 5 and y is 0.3. In some examples, x is 6 and y is 0.3. In some examples, x is 8 and y is 0.3. In some examples, x is 9 and y is 0.3. In some examples, x is 7 and y is 0.22. In some examples, x is 5 and y is 0.22. In some examples, x is 6 and y is 0.22. In some examples, x is 8 and y is 0.22. In some examples, x is 9 and y is 0.22. Garnet as used herein also includes, but is not limited to, Li. x La 3 Zr 2 O 12 +yAl 2 O 3 In one embodiment, the Li-filled garnets herein include Li 7 Li 3 Zr 2 O 12 In another embodiment, the Li-filled garnets herein have a composition of Li 7 Li 3 Zr 2 O 12 .Al 2 O 3 In yet another embodiment, the Li-filled garnets herein have a composition of Li 7 Li 3 Zr 2 O 12 .0.22Al 2 O 3 In yet another embodiment, the Li-filled garnets herein have a composition of Li 7 Li 3 Zr 2 O 12 .0.35Al 2 O 3 In certain other embodiments, the Li-filled garnets herein have a composition of Li 7 Li 3 Zr 2 O 12 .0.5Al 2 O 3 In another embodiment, the Li-filled garnets herein have a composition of Li 7Li 3 Zr 2 O 12 .0.75Al 2 O 3 The composition is:

[0049] As used herein, garnet refers to YAG garnet (i.e., yttrium aluminum garnet, or, e.g., YAG garnet). 3 Al 5 O 12 As used herein, garnet does not include pyrope, almandine, spessartine, grossular, hessonite, or silicate-based garnets such as yellow garnet, tsavorite, uvarovite, and andradite, as well as the solid solutions pyrope-almandine-spessarite and uvarovite-grossular-andradite. Garnets herein are defined as garnets of the general formula X 3 Y 2 (SiO 4 ) 3 wherein X is Ca, Mg, Fe, and / or Mn; and Y is Al, Fe, and / or Cr.

[0050] As used herein, the phrase "green thin film" or "green tape" refers to an unsintered tape or thin film comprising lithium-loaded garnet, a precursor of lithium-loaded garnet, or a combination thereof, and at least one of a binder, a plasticizer, carbon, a dispersant, a solvent, or a combination thereof. As used herein, "green thin film tape" refers to a roll, continuous layer, or cut portion thereof, of a cast tape of green thin film, either dried or undried. A green body is used interchangeably with a green thin film or a green tape. A green tape may also include a patch of green body deposited on a metal layer (i.e., a patch coating of a metal layer).

[0051] As used herein, "atmosphere control device" refers to a system that controls moisture content, oxygen content, gas flow rate, gas temperature, gas content(s), gas concentration(s), total pressure, vacuum, and combinations thereof within an enclosed or confined space. The atmosphere control device may be dynamic in the sense that the system changes the atmosphere in response to sensed conditions to change the atmosphere to more closely adhere to certain predetermined conditions. The atmosphere in this case refers to the gaseous environment in direct contact with the green tape being heated, fired, sintered, or cooled; or the gaseous environment in direct contact with the sintered tape being heated, sintered, annealed, or cooled. In some examples described herein, the atmosphere control device includes controlling the flow rate of an inlet gas that includes any of oxygen, argon, nitrogen, helium, and / or hydrogen. In some examples described herein, the atmosphere control device includes controlling the amount of water, oxygen, and lithium present in a gaseous state in direct contact with the green tape being heated, fired, sintered, or cooled; or in direct contact with the sintered tape being heated, sintered, annealed, or cooled. The atmosphere control system may use various gas curtains, gas densities, gas flow rates, gas flow directions, or gas pulses in, around, and near the oven, furnace, and any inlets or outlets, as well as any openings that allow materials such as green tapes or sinters to enter or leave the oven or furnace. The atmosphere control system may refer to a system in which nitrogen gas, argon gas, forming gas, dry air, or humidified air is used in an enclosed or closed space. The atmosphere control system may refer to a system in which a partial vacuum can be applied to the system, such as when the pressure is less than atmospheric pressure.

[0052] As used herein, a "sintered bilayer" refers to a bilayer structure that includes a sintered solid electrolyte and a metal foil. As used herein, a "green bilayer" refers to a bilayer structure that includes a green thin film and a metal foil.

[0053] As used herein, a "gas curtain" refers to a gas flow rate at a particular inlet or outlet of an oven (e.g., green tape inlet and sintered thin film outlet) where the gas flow rate is determined. For example, the gas flow rate can be 1-50 liters / minute at standard pressure and temperature. For example, the gas flow rate can be greater than 50 liters / minute at standard pressure and temperature. The gas curtain can have a pressure sensor at the outlet. The gas curtain flows across the inlet or outlet of the oven and controls the flow of gas within the oven. The gas curtain can help maintain a particular atmosphere within the oven by partially or completely preventing gas from entering or leaving the oven.

[0054] As used herein, the phrase "dry air" refers to air that has a low amount of moisture. Dry air may be provided to a clean room. Dry air is characterized by having a dew point of less than -20°C, less than -30°C, less than -40°C, less than -50°C, less than -60°C, or less than -70°C.

[0055] FIG. 1 shows a schematic diagram of an RTP apparatus and associated method according to one embodiment. Heating elements 110 and 120 apply heat to a material 130 placed between them at a desired temperature for a desired period of time to produce a sintered element 140 that functions as a separator between the anode and cathode elements of a solid-state battery. The heating elements 110 and 120 are positioned to be a desired distance from the material 130. In one embodiment, the material 130 is placed on the heating element 120. In one embodiment, the material 130 is placed on a setter 135 that is placed on the heating element 120. In one embodiment, one of the heating elements 110 and 120 can be omitted.

[0056] As used herein, area specific resistance (ASR) is measured by electrochemical cycling using an Arbin or Biologic instrument, unless stated to the contrary.

[0057] As used herein, ionic conductivity is measured by electrical impedance spectroscopy.

[0058] As used herein, the phrase "ambient conditions" refers to room temperature and approximately 78% N 2 and 21% O 2 Ambient conditions refers to a natural atmosphere, such as that of planet Earth, that contains air and / or moisture is also present. Ambient conditions include standard temperature and pressure, and a relative humidity of at least 1%.

[0059] As used herein, "binder" refers to a polymer that has the ability to enhance the adhesion and / or cohesion of materials, such as solids in green tapes. Suitable binders may include, but are not limited to, PVDF, PVDF-HFP, SBR, and ethylene alpha-olefin copolymers. "Binder" refers to a material that aids in the adhesion of another material. For example, as used herein, polyvinyl butyral is a binder because it is useful for adhering garnet materials. Other binders may include polycarbonates. Other binders may include polyacrylates and polymethacrylates. These examples of binders are not intended to limit the full scope of binders contemplated herein, but rather serve merely as examples. Binders useful in the present disclosure include, but are not limited to, polypropylene (PP), polyethylene, atactic polypropylene (aPP), isotactic polypropylene (iPP), ethylene propylene rubber (EPR), ethylene pentene copolymer (EPC), polyisobutylene (PIB), styrene butadiene rubber (SBR), polyolefins, polyethylene-co-poly-l-octene (PE-co-PO), polyethylene-co-poly(methylenecyclopentane) (PE-co-PMCP), poly(methyl methacrylate) (and other acrylics), acrylics, polyvinyl acetoacetal resins, polyvinyl butyral resins, PVB, polyvinyl acetal resins, stereoblock polypropylene, polypropylene polymethylpentene copolymers, polyethylene oxide (PEO), PEO block copolymers, and silicones.In some examples, including any of the foregoing, the binder may be polyacrylonitrile (PAN), polypropylene, polyethylene, polyethylene oxide (PEO), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polyvinylpyrrolidone (PVP), polyethylene oxide poly(allyl glycidyl ether) PEO-AGE, polyethylene oxide 2-methoxyethoxyethyl glycidyl ether (PEO-MEEGE), polyethylene oxide 2-methoxyethoxyethyl glycidyl poly(allyl glycidyl ether) (PEO-MEEGE-AGE), poly(ethylene oxide) 2-methoxyethoxyethyl glycidyl poly(allyl glycidyl ether) (PEO-MEEGE-AGE), poly(ethylene oxide) 2-methoxyethoxyethyl glycidyl poly(allyl glycidyl ether) (PEO-MEEGE-AGE), poly(ethylene oxide) 2-methoxyethoxyethyl glycidyl poly(allyl glycidyl ether) (PEO-MEEGE-AGE), poly(ethylene oxide) 2-methoxyethoxyethyl glycidyl poly(aryl ... The polymer is selected from the group consisting of fluororubber, polyvinylidene fluoride (PVDF), polyvinylidene hexafluoropropylene (PVDF-HFP), ethylene propylene (EPR), nitrile rubber (NPR), styrene butadiene rubber (SBR), polybutadiene polymer, polybutadiene rubber (PB), polyisobutadiene rubber (PIB), polyolefin, α-polyolefin, ethylene α-polyolefin, polyisoprene rubber (PI), polychloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), and polyethyl acrylate (PEA).

[0060] As used herein, the phrase "thin film casting" refers to a process of delivering or transporting a liquid or slurry into a mold or onto a substrate so that the liquid or slurry forms or is formed into a thin film. Casting can be done by doctor blade, meyer rod, comma coater, gravure coater, microgravure, reverse comma coater, slot die, slip and / or tape casting, and other methods.

[0061] Figure 2 shows a schematic diagram of an RTP apparatus and associated method according to one embodiment. As in Figure 1, heating elements 110 and 120 apply heat to material 130 disposed between them to produce sintered element 140. A controller 250 controls heating elements 110 and 120 to heat material 130 to a desired temperature. In some examples, the controller controls the temperature of the furnace such that it ramps up to a temperature within the desired temperature range at a rate of up to 300°C per minute.

[0062] The controller 250 also controls a conveyor including rollers 270, 275 and conveyor belt 280 to transport material 130 disposed on the conveyor belt 280 between heating elements 110 and 120. The controller 250 further controls the conveyor such that material 130 remains between heating elements 110 and 120 for a desired period of time. In one embodiment, the conveyor belt 280 is disposed above the heating element 120. In one embodiment, material 130 is disposed above the conveyor 280. In one embodiment, material 130 is disposed above a setter 135 disposed above the conveyor 280. In one embodiment, one of the heating elements 110 and 120 can be omitted.

[0063] In some embodiments, the heating elements 110 and 120 can be carbon plates or carbon paper. In some examples, the carbon plates or carbon paper include conductive carbon. In some embodiments, the heating elements 110 and 120 can be molybdenum plates or molybdenum paper. In some examples, the molybdenum plates or molybdenum paper can include conductive molybdenum. An electric current can be applied to heat the conductive carbon plate or conductive carbon paper elements at a suitable rate to a temperature that facilitates sintering within the temperature ranges described herein.

[0064] In one embodiment, the heating element(s) may be at a distance of 1 mm to 2000 mm from the material being sintered. In one embodiment, the heating element(s) may be at a distance of 1 mm to 200 mm from the material being sintered. In one embodiment, the heating element(s) may be as close as 1 mm to 10 mm from the material being sintered. In some embodiments, the distance of the heating element(s) from the material being sintered can be measured in a number of ways, depending on the position of the material relative to the heating element(s) as it passes through the conveyor.

[0065] In one embodiment, the sintering temperature may be in the range of 900°C to 1,200°C. In one embodiment, the sintering temperature may be in the range of 950°C to 1,150°C. In one embodiment, the sintering temperature may be in the range of 1,000°C to 1,100°C. In one embodiment, the sintering temperature may be in the range of 1,000°C to 1,300°C. In one embodiment, the sintering temperature may be in the range of 1,050°C to 1,250°C. In one embodiment, the sintering temperature may be in the range of 1,100°C to 1,200°C.

[0066] In one embodiment, the heating time may be in the range of 5 seconds to 30 minutes. In one embodiment, the heating time may be in the range of 5 seconds to 25 minutes. In one embodiment, the heating time may be in the range of 5 seconds to 20 minutes. In one embodiment, the heating time may be in the range of 5 seconds to 15 minutes. In one embodiment, the heating time may be in the range of 5 seconds to 10 minutes. In one embodiment, the heating time may be in the range of 5 seconds to 5 minutes. In one embodiment, the heating time may be in the range of 5 seconds to 4 minutes. In one embodiment, the heating time may be in the range of 5 seconds to 3 minutes. In one embodiment, the heating time may be in the range of 5 seconds to 4 minutes. In one embodiment, the heating time may be in the range of 5 seconds to 1 minute.

[0067] In some examples, heating elements 110 and 120 can have the same area as material 130. In some examples, heating elements 110 and 120 can be longer and the same width as material 130. In some examples, heating elements 110 and 120 can be the same length and wider than material 130. In some examples, heating elements 110 and 120 can be shorter than material 130. In embodiments where there is a single heating element, the heating element can have any of the area relationships just described for material 130.

[0068] In some examples, material 130 may have a length of about 50 mm to about 300 mm and a width of about 50 mm to about 300 mm. In some examples, material 130 may have a length of about 50 mm to about 150 mm and a width of about 50 mm to about 150 mm. In some examples, material 130 may have a length of about 60 mm to about 120 mm and a width of about 60 mm to about 120 mm. In one specific example, material 130 may be about 64 mm by about 79 mm after sintering. In one specific example, material 130 may be about 64 mm by about 80 mm after sintering. In one specific example, material 130 may be about 64 mm by about 85 mm after sintering. In one specific example, material 130 may be about 65 mm by about 80 mm after sintering. In one specific example, material 130 may be about 65 mm by about 85 mm after sintering. In one specific example, material 130 may be about 75 mm by about 90 mm after sintering. In one specific example, material 130 may be about 110 mm by about 110 mm after sintering. In one specific example, material 130 may be about 115 mm by about 115 mm after sintering. In one specific example, material 130 may be about 110 mm by about 115 mm after sintering.

[0069] In some examples, the material densifies and reduces in size when subjected to a sintering process from a green thin film on a metal foil to a sintered material on a metal foil. As described herein, the x and y directions are along the width and length of the green thin film, and the z direction is along the height of the green thin film.

[0070] In some cases, the material shrinks primarily in the z-direction. In some cases, the height of the green film of the bilayer decreases by at least 30%, 40%, 50%, or 60%. In some cases, the height of the green film of the bilayer decreases by about 40%, 45%, or 50%.

[0071] The thickness of the green bilayer can be measured with a drop gauge or FIB cut with SEM imaging.

[0072] The thickness of the sintered bilayer can be measured by SEM imaging, ion mill cross sections, or FIB cuts with dual-side opposing interferometry.

[0073] In one embodiment, the sintering step is carried out under a reducing gas atmosphere or an inert gas atmosphere. The inert atmosphere is argon (Ar) or nitrogen (N 2 The reducing atmosphere may include hydrogen (H 2 ) mixed with Ar or H 2 Mixed with N 2 may include.

[0074] In one embodiment, the sintering step involves the use of oxidizing agents mixed into a gas or atmosphere that contacts the green tape. These oxidizing agents include H 2 O, O 2 or clean dry air. In certain instances, the sintering oven does not include an oxidizer mixed into the gas or atmosphere that contacts the sintered thin film.

[0075] Oxygen or O in the gas for the processes described herein 2 The level may be less than about 100 ppm, 50 ppm, or 10 ppm. 2 The levels may be less than about 100 ppm, 50 ppm, or 10 ppm.

[0076] In some examples, the sintering process includes using argon (Ar) gas.

[0077] In some instances, the sintering process may be carried out using nitrogen (N 2 ) gas.

[0078] In some examples, the sintering process may be carried out using hydrogen (H 2 ) gas. In some instances, H 2 The gas is present at approximately 5% v / v.

[0079] In some instances, the sintering process may be carried out using an aqueous (H 2 O) Involves the use of gas.

[0080] In one embodiment, the atmosphere within the apparatus is uniform or substantially uniform. The atmosphere of the inert gas or gas mixture is uniform throughout the apparatus, or at least uniform above and / or below the material to be sintered. In one embodiment, the temperature within the apparatus is uniform or substantially uniform. The temperature of the inert gas or gas mixture is uniform throughout the apparatus, or at least uniform above and / or below the material to be sintered.

[0081] In some instances, this process involves using an atmospheric control device with a narrow oven opening around the material being sintered.

[0082] In some examples, using an atmospheric control device includes using excess flow at the inlet and outlet of the oven. In some examples, using an atmospheric control device includes using N 2 or using an Ar-filled glove box. In some examples, using an atmospheric control device includes using overpressure in an oven.

[0083] In some examples, using an atmospheric control device includes using atmospheric pressure within the tool. In some cases, a partial vacuum can be used, with pressures of about 0.01 Torr (1.3 Pa), about 0.1 Torr (13.3 Pa), or about 0.5 Torr (66.7 Pa). In some cases, airflow can be reintroduced into the system to which the vacuum was applied.

[0084] In some instances, the use of an atmosphere control device can be used to control the H 2 In some examples, using an atmosphere control device includes controlling the amount of O in the heating device. 2 In some examples, using an atmosphere control device includes controlling the amount of O in the heating device. 2 In some examples, using an atmosphere control device includes controlling the amount of O in the heating device to a level less than 100 ppm. 2 In some examples, using an atmosphere control device includes controlling the amount of O in the heating device to a level of less than 10 ppm. 2 In some examples, using an atmosphere control device includes controlling the amount of H in the heating device to a level of less than 1 ppm. 2 In some examples, using an atmosphere control device includes controlling the amount of N 2 This includes controlling the amount of

[0085] In some instances, the use of an atmosphere control device can be used to control the H 2 In some examples, using an atmosphere control device includes controlling the amount of H in the heating device. 2 In some examples, using an atmosphere control device includes controlling the amount of H in the heating device to a level less than 100 ppm. 2 This includes controlling the amount of O to levels below 10 ppm.

[0086] In some examples, using the atmospheric control device includes using a forming gas in a heating device. In a particular example, the forming gas is hydrogen (H2 In some examples, using the atmosphere control system includes using a forming gas in a heating system. In a particular example, the forming gas is a mixture of hydrogen (H 2 ) and nitrogen (N 2 In some examples, using the controlled atmosphere system includes using a forming gas in a heating system. In a particular example, the forming gas is a mixture of H 2 , Ar, and N 2 In some of these examples, H 2 is a few volume percent of forming gas. For example, in a specific example, H 2 is present in the forming gas at 1 vol%, 2 vol%, 3 vol%, 4 vol%, 6 vol%, 7 vol%, 8 vol%, 9 vol%, or 10 vol%. 2 is present in the forming gas at about 1 vol.%, about 2 vol.%, about 3 vol.%, about 4 vol.%, about 6 vol.%, about 7 vol.%, about 8 vol.%, about 9 vol.%, or about 10 vol.%. In other specific examples, H 2 is present in the forming gas at about 1-2 vol.%, about 2-3 vol.%, about 3-4 vol.%, about 4-5 vol.%, about 6-7 vol.%, about 7-8 vol.%, about 8-9 vol.%, or about 9-10 vol.%. 2 is present in the forming gas at 1-2 vol%, 2-3 vol%, 3-4 vol%, 4-5 vol%, 6-7 vol%, 7-8 vol%, 8-9 vol%, or 9-10 vol%. 2 is present in the forming gas at 1 to 5 volume %, 2 to 5 volume %, 3 to 5 volume %, 5 to 9 volume %, 5 to 7 volume %, 4 to 6 volume %, 3 to 7 volume %, or 2 to 8 volume %.

[0087] In another example, the use of an atmosphere control device may include mixing Ar gas, N 2 In a particular example, the gas is Ar. In some examples, the gas is N 2 In another example, the gas is Ar and N 2 It is a mixture of.

[0088] In some instances, and in some portions of the production line, such as portions of the production line where sintering is not occurring, the use of atmospheric control equipment includes the use of an oxidizing gas, such as H 2 O may be used alone or in combination with the gases in the previous paragraph. For example, O 2 may be used alone or in combination with the gases in the preceding paragraph. For example, CDA (clean dry air) may be used alone or in combination with the gases in the preceding paragraph.

[0089] In some examples, using the controlled atmosphere includes using an enclosure to provide a sealed environment in the controlled atmosphere around or near the heating device. For example, the enclosure is filled with nitrogen and some areas are exposed to a reducing environment. The reducing environment may be H 2 Alternatively, this can be achieved by providing a partial pressure of CO.

[0090] In some instances, the green tape is rapidly sintered. The time that any portion of the thin film is exposed to a temperature above room temperature can be from 30 minutes to 10 hours. The time that any portion of the thin film is exposed to a temperature above room temperature can be from 30 minutes to 5 hours. The time that any portion of the thin film is exposed to a temperature above room temperature can be from 1 hour to 5 hours. The time that any portion of the thin film is exposed to a temperature above room temperature can be from 2 hours to 4 hours.

[0091] In some examples, the green tape is sintered rapidly. The time that any portion of the thin film is exposed to the sintering temperature can be between 15 seconds and 20 minutes. In other examples, the time that any portion of the thin film is exposed to the sintering temperature can be between 1 minute and 10 minutes. In other examples, the time that any portion of the thin film is exposed to the sintering temperature can be between 1 minute and 5 minutes. In other examples, the time that any portion of the thin film is exposed to the sintering temperature can be between 1 minute and 2 minutes.

[0092] To avoid surface contamination of the sintered or pre-sintered material as it passes through the continuous manufacturing line (CML), the thin film can be cooled to below 40° C. In some examples, the thin film can be cooled to below 40° C. 2 The atmosphere is kept low in O content. For example, H 2 O The content may be less than 10 ppm. In some examples, the thin film is maintained in an atmosphere that is primarily argon gas. In some examples, the thin film is maintained in an atmosphere that is primarily nitrogen gas. In some examples, the thin film is maintained in clean dry air (CDA).

[0093] In some instances, an airbox (tunnel structure) with an exhaust system is used.

[0094] In some examples, an air box with a feedback loop is provided to connect the gas supply and O 2 It is used to form a sensor into a heating device.

[0095] In some instances, prior to sintering, the material to be sintered is subjected to binder burnout by firing (BBO). In BBO, organics in the material are evaporated or burned out of the material to be sintered. In BBO, the atmosphere in contact with the material to be sintered can be oxidizing. In some instances, the BBO atmosphere is not oxidizing and organics are evaporated from the material to be sintered. The BBO step is performed prior to the sintering step.

[0096] FIG. 3 shows a schematic diagram of an RTP apparatus and associated method according to one embodiment. The apparatus of FIG. 3 uses heat lamps 300 to sinter material 130. In one embodiment, lamps 300 are halogen lamps. Heat from heat lamps 300 passes through a receptacle 310 that holds material 130. In one embodiment, the receptacle may function as a susceptor. In one embodiment, the material is placed on a setter 315. In one embodiment, the setter may be omitted. In one embodiment, the setter 315 may function as a susceptor.

[0097] Non-limiting examples of setters are described, for example, in PCT published patent applications WO 2016168723A1 and WO 2016168691A1, both published October 20, 2016, and U.S. Patent No. 10,563,918, issued February 18, 2020. The entire contents of the aforementioned PCT published patent applications and U.S. patents are incorporated herein by reference for all purposes.

[0098] As described herein, the method of sintering the material can be performed by a carbon plate-based heating method, tool, or device.As described herein, the method of sintering the material can be performed by a lamp-based heating method, tool, or device.

[0099] In one embodiment, the lid 320 fits into the opening 330. The solid arrow 340 indicates faster heat transfer. The dashed arrow 350 indicates slower heat transfer. In some embodiments, the lid can transmit more than 50% of the light incident in the wavelength range of 300-700 nm, or the wavelength range of 800-2500 nm, or the wavelength range of 2.5-1,000 μm, or the wavelength range of 100-400 nm. In one embodiment, the device can be controlled to flow gas to the inner surface of the lid 320. In one embodiment, the lid 320 can be omitted, especially if the stack including the material 130 and the setter 315 is relatively thick compared to the height of the opening 330. In one embodiment, the material 130 is sintered to form the sintered element 140, as shown in FIGS. 1 and 2. As described above, the sintered element 140 can function as a separator in a solid-state battery. In one embodiment, the separator is a solid electrolyte. In one embodiment, the separator comprises a Li-loaded garnet.

[0100] FIG. 5 shows an apparatus for performing rapid thermal processing according to one embodiment. In FIG. 5, a controller 250 controls a conveyor 290 including a number of rollers 295 and a number of heating elements 110, each of which is in a separate zone 150 of the apparatus according to the different embodiment as shown. Also in FIG. 5, material 130 is disposed on a setter 135. In a different embodiment, material 130 may include lithium loaded garnet as described above. In a different embodiment, setter 135 may include a foil of the type described above such that material 130 and setter 135 together form a bilayer structure that passes through the apparatus of FIG. 5 to obtain sintered material 140 as shown.

[0101] In some embodiments, there may be more than the three zones 150 shown in Figure 5. In some embodiments, there may be anywhere from 1 to 50 such zones. One or more central zones in the apparatus may perform sintering of the material 130, with preceding zones heating the material before sintering and subsequent zones cooling the material after sintering. In some embodiments, the atmosphere in the various zones may be either humid or dry.

[0102] In some embodiments, the conveyor 290 can be one long continuous conveyor with the rollers 295 along one straight path. In some embodiments, the rollers 295 can be arranged in a path that appears as a square, a rectangle, another polygonal structure, an ellipse, or a circle. In these latter embodiments, the conveyor represents a continuous path where material can be placed on and removed from the conveyor at nearby points rather than at the beginning and end.

[0103] In some embodiments, the controller 250 can individually control the zones 150 to define a desired temperature profile for heating the material 130 and cooling the sintered material 140. In one embodiment, the central zone or zones 150 can sinter the material 130 at a temperature ranging from 900° to 2,000° C. In one embodiment, the temperature can range from 1,000° to 1,900° C. In one embodiment, the temperature can range from 1,100° to 1,800° C. In one embodiment, the temperature can range from 1,200° to 1,700° C. In one embodiment, the temperature can range from 1,000° to 1,700° C. In one embodiment, the temperature can range from 1,100° to 1,600° C. In one embodiment, the temperature can range from 1,200° to 1,500° C. In one embodiment, the temperature can range from 1,000° to 1,400° C. In one embodiment, the temperature may range from 1,100° C. to 1,300° C. In one embodiment, the temperature may range from 1,000° C. to 1,200° C.

[0104] Depending on the embodiment, the temperature profile just discussed may heat the material 130 at any of several desired rates until it reaches the zone 150 where the material 130 is sintered. In different embodiments, the rate may vary from 10° C. / min to 250° C. / min. In different embodiments, the rate may vary from 20° C. / min to 200° C. / min. In different embodiments, the rate may vary from 25° C. / min to 150° C. / min. In different embodiments, the rate may vary from 30° C. / min to 100° C. / min. In different embodiments, the rate may vary from 10° C. / min to 50° C. / min. In different embodiments, the rate may vary from 15° C. / min to 45° C. / min. In different embodiments, the rate may vary from 20° C. / min to 40° C. / min. In different embodiments, the rate may vary from 10° C. / min to 40° C. / min. In different embodiments, the rate can vary from 15° C. / min to 35° C. / min. In different embodiments, the rate can vary from 20° C. / min to 30° C. / min.

[0105] Although some figures herein show a bi-layer structure being transported through a furnace, in embodiments there is additional structure surrounding the bi-layer structure. Some of this structure may be referred to as furniture. In embodiments, one portion of the fixture is below the bi-layer structure and another portion of the fixture is above the bi-layer structure. In different embodiments, these portions of the fixture are planar or plate-like and have lengths and widths that are greater than the length and width of the bi-layer structure sandwiched between them.

[0106] In some embodiments, the material of the fixture used to transport the bilayer structure through the series of furnace zones is alumina (Al 2 O 3 ), zirconium-toughened alumina (ZTA), mullite (3Al 2 O 3 2SiO 2 Or 2Al 2 O 3 SiO 2 The material may be selected from the group consisting of SiO2, aluminum nitride (AlN), or silicon carbide (SiC). In one embodiment, the upper fixture portion of the bi-layer structure may be formed from one of the materials mentioned above different than the portion of the fixture between the conveyor and the bi-layer structure. By way of example only, if the fixture is formed from alumina, one portion may be formed from printed alumina and one may be formed from dense alumina.

[0107] In some embodiments, the frame is disposed between the upper portion of the fixture and the bilayer structure such that the thin film does not contact the upper portion of the fixture. In some embodiments, the material of the frame disposed between the fixture and the foil can be selected from the group consisting of porous alumina, alumina-zirconia mixtures, lithium aluminate, lithium tantalate, alumina, silica, silicates such as cordierite, Ni, iron alloys, nickel alloys, cobalt alloys, iron nickel cobalt alloys, or combinations thereof. In one embodiment, the material of the frame can be textured on one or both sides. The texturing can reduce the contact area between the frame and the foil and increase the BBO pathway. In one embodiment, the texturing can include vertical grooves on the frame. In one embodiment, the texturing can include horizontal grooves on the frame. In one embodiment, the texturing can include horizontal and vertical grooves on the frame. In one embodiment, the grooves can be periodically (i.e., equidistant from each other). In one embodiment, where one side of the material is textured, the texturing can be facing the material.

[0108] 6A and 6B respectively show top and bottom views of a frame structure according to different embodiments. In FIG. 6A, the frame structure 600 comprises a frame 610 with an opening 620. There is a depending portion 630 that extends below the frame 610. The frame 610 is interposed between the upper fixture portion and the bilayer structure to prevent the central portion of the material of the bilayer structure from contacting the upper portion of the fixture. When the bilayer structure is assembled in the fixture for sintering, the portion 630 contacts the bilayer structure and prevents the frame 610 from contacting the bilayer structure. FIG. 6B shows a top view of the frame structure 600, with the portion 630 shown in dotted line below the frame 610. FIG. 6C shows the frame 610 superimposed on the material 130.

[0109] Figures 7A and 7B show a structure 700 arranged in a furnace according to different embodiments. Figure 7A is an exploded view and Figure 7B is an assembled view. In these figures, a bilayer structure including material 130 and foil 135 is arranged on a lower fixture plate 720. A frame structure 600 is arranged on this bilayer structure. An upper fixture plate 710 is arranged on the frame structure 600. In the description accompanying the various embodiments herein, the upper and lower fixture plates 710, 720 may be collectively referred to as fixtures.

[0110] FIG. 8 shows a structure corresponding to a portion of FIG. 5, in which the structure 700 shown in FIGS. 7A and 7B is passed through a furnace to produce the sintered material 140.

[0111] During sintering, the bilayer can be oriented in one of two orientations relative to the ground: green thin film on top and metal foil on the bottom or metal foil on top and green thin film on the bottom. The example described herein has metal foil on the bottom to minimize interaction with the setter or support, and the green thin film on top to allow the binder to detach from the thin film during binder burnout heating.

[0112] In some embodiments, the fixture may have a range of dimensions from 50x50mm to 200x200mm. The fixture may have dimensions up to 300x300mm. The fixture need not be square. In one embodiment, the width of the fixture may be about 50mm. In one embodiment, the width of the fixture may be about 60mm. In one embodiment, the width of the fixture may be about 70mm. In one embodiment, the width of the fixture may be about 80mm. In one embodiment, the width of the fixture may be about 90mm. In one embodiment, the width of the fixture may be about 100mm. In one embodiment, the width of the fixture may be about 110mm. In one embodiment, the width of the fixture may be about 120mm. In one embodiment, the width of the fixture may be about 130mm. In one embodiment, the width of the fixture may be about 140mm. In one embodiment, the width of the fixture may be about 150mm. In one embodiment, the width of the fixture may be about 160mm. In one embodiment, the fastener width may be about 170 mm. In one embodiment, the fastener width may be about 180 mm. In one embodiment, the fastener width may be about 190 mm. In one embodiment, the fastener width may be about 200 mm. In some embodiments, fastener width increments of less than 10 mm may be used.

[0113] In one embodiment, the length of the fastener may be about 50 mm. In one embodiment, the length of the fastener may be about 60 mm. In one embodiment, the length of the fastener may be about 70 mm. In one embodiment, the length of the fastener may be about 80 mm. In one embodiment, the length of the fastener may be about 90 mm. In one embodiment, the length of the fastener may be about 100 mm. In one embodiment, the length of the fastener may be about 110 mm. In one embodiment, the length of the fastener may be about 120 mm. In one embodiment, the length of the fastener may be about 130 mm. In one embodiment, the length of the fastener may be about 140 mm. In one embodiment, the length of the fastener may be about 150 mm. In one embodiment, the length of the fastener may be about 160 mm. In one embodiment, the length of the fastener may be about 170 mm. In one embodiment, the length of the fastener may be about 180 mm. In one embodiment, the length of the fastener may be about 190 mm. In one embodiment, the length of the fastener may be about 200 mm. In some embodiments, increments of less than 10 mm may be used in the length of the fastener.

[0114] In some embodiments, the foil may have a range of dimensions from about 40x40 mm to about 190x190 mm. The fixture need not be square. In one embodiment, the width of the fixture may be about 40 mm. In one embodiment, the width of the fixture may be about 50 mm. In one embodiment, the width of the fixture may be about 60 mm. In one embodiment, the width of the fixture may be about 70 mm. In one embodiment, the width of the fixture may be about 80 mm. In one embodiment, the width of the fixture may be about 90 mm. In one embodiment, the width of the fixture may be about 100 mm. In one embodiment, the width of the fixture may be about 110 mm. In one embodiment, the width of the fixture may be about 120 mm. In one embodiment, the width of the fixture may be about 130 mm. In one embodiment, the width of the fixture may be about 140 mm. In one embodiment, the width of the fixture may be about 150 mm. In one embodiment, the width of the fixture may be about 160 mm. In one embodiment, the fastener width can be about 170 mm. In one embodiment, the fastener width can be about 180 mm. In one embodiment, the fastener width can be about 190 mm. In some embodiments, fastener width increments of less than 10 mm can be used.

[0115] In one embodiment, the length of the foil is greater than about 50 mm. In one embodiment, the length of the foil may be about 60 mm. In one embodiment, the length of the foil may be about 70 mm. In one embodiment, the length of the foil may be about 80 mm. In one embodiment, the length of the foil may be about 90 mm. In one embodiment, the length of the foil may be about 100 mm. In one embodiment, the length of the foil may be about 110 mm. In one embodiment, the length of the foil may be about 120 mm. In one embodiment, the length of the foil may be about 130 mm. In one embodiment, the length of the foil may be about 140 mm. In one embodiment, the length of the foil may be about 150 mm. In one embodiment, the length of the foil may be about 160 mm. In one embodiment, the length of the foil may be about 170 mm. In one embodiment, the length of the foil may be about 180 mm. In one embodiment, the length of the foil may be about 190 mm. Generally, any length between 40 mm and 190 mm may be used for the foil length depending on the embodiment. Generally, the foil will be a single sheet of metal foil, not a ribbon significantly longer than it is wide.

[0116] Another way to look at the size of the foil compared to the size of the fixture is the distance on each side between the perimeter of the foil and the perimeter of the fixture. In one embodiment, the distance on each side between the foil and the fixture may be about 5 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 6 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 7 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 8 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 9 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 10 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 11 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 12 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 13 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 14 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 15 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 16 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 17 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 18 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 19 mm. In one embodiment, the distance on each side between the foil and the fixture may be about 20 mm.

[0117] In one embodiment, the outer dimensions of the frame may be the same as the dimensions of the foil. The width of each side of the frame may vary as needed to provide adequate separation from the upper portion of the fixture. In one embodiment, the width of each side of the frame may be about 1 mm. In one embodiment, the width of each side of the frame may be about 1.5 mm. In one embodiment, the width of each side of the frame may be about 2 mm. In one embodiment, the width of each side of the frame may be about 2.5 mm. In one embodiment, the width of each side of the frame may be about 3 mm. In one embodiment, the width of each side of the frame may be about 3.5 mm. In one embodiment, the width of each side of the frame may be about 4 mm. In one embodiment, the width of each side of the frame may be about 4.5 mm. In one embodiment, the width of each side of the frame may be about 5 mm. In one embodiment, the width of each side of the frame may be about 5.5 mm. In one embodiment, the width of each side of the frame may be about 6 mm.

[0118] In some examples, including any of the above, the solid electrolyte has a rectangular shape with two surfaces, the top and bottom, having the largest geometric surface area. As used herein, the geometric surface area is the width multiplied by the length of the area of ​​the considered surface, assuming a flat surface. The four end faces are angled at about 90° with the top and bottom faces, and each end face has a geometric surface area smaller than the geometric surface area of ​​either the top or bottom face. In these examples, two of the four end faces have a smaller geometric surface area than the other two of the four end faces.

[0119] In some examples, including any of the above, the solid electrolyte has a square shape with two surfaces, the top and bottom, having the largest geometric surface area. The four end faces are angled at about 90° with respect to the top and bottom faces, and each end face has a geometric surface area that is smaller than the geometric surface area of ​​either the top or bottom face. In these examples, the four end faces have approximately equal surface areas.

[0120] In some examples, including any of the foregoing, the unsintered bilayer has a thickness of 1 μm to 100 μm. In some examples, the unsintered bilayer has a thickness of 20 μm to 100 μm. In some examples, the unsintered bilayer has a thickness of 40 μm to 100 μm. In some examples, the unsintered bilayer has a thickness of 20 μm to 80 μm. In some examples, the unsintered bilayer has a thickness of 40 μm to 80 μm. In some examples, the unsintered bilayer has a thickness of 20 μm to 60 μm. In some examples, the unsintered bilayer has a thickness of 10 μm to 50 μm. In some examples, the unsintered bilayer has a thickness of 10 μm to 40 μm. In some examples, the unsintered bilayer has a thickness of 10 μm to 30 μm. In some examples, the unsintered bilayer has a thickness of about 10 μm. In some examples, the unsintered bilayer has a thickness of about 11 μm. In some examples, the unsintered bilayer has a thickness of about 12 μm. In some examples, the unsintered bilayer has a thickness of about 13 μm. In some examples, the unsintered bilayer has a thickness of about 14 μm. In some examples, the unsintered bilayer has a thickness of about 15 μm. In some examples, the unsintered bilayer has a thickness of about 16 μm. In some examples, the unsintered bilayer has a thickness of about 17 μm. In some examples, the unsintered bilayer has a thickness of about 18 μm. In some examples, the unsintered bilayer has a thickness of about 19 μm. In some examples, the unsintered bilayer has a thickness of about 20 μm. In some examples, the unsintered bilayer has a thickness of about 21 μm. In some examples, the unsintered bilayer has a thickness of about 22 μm. In some examples, the unsintered bilayer has a thickness of about 23 μm. In some examples, the unsintered bilayer has a thickness of about 24 μm. In some examples, the unsintered bilayer has a thickness of about 25 μm. In some examples, the unsintered bilayer has a thickness of about 26 μm. In some examples, the unsintered bilayer has a thickness of about 27 μm. In some examples, the unsintered bilayer has a thickness of about 28 μm. In some examples, the green bilayer has a thickness of about 29 μm. In some examples, the green bilayer has a thickness of about 30 μm. In some examples, the green bilayer has a thickness of about 31 μm. In some examples, the green bilayer has a thickness of about 32 μm. In some examples, the green bilayer has a thickness of about 33 μm. In some examples, the green bilayer has a thickness of about 34 μm.In some examples, the green bilayer has a thickness of about 35 μm. In some examples, the green bilayer has a thickness of about 36 μm. In some examples, the green bilayer has a thickness of about 37 μm. In some examples, the green bilayer has a thickness of about 38 μm. In some examples, the green bilayer has a thickness of about 39 μm. In some examples, the green bilayer has a thickness of about 40 μm.

[0121] In some examples, including any of the foregoing, the sintered bilayer has a thickness of 1 μm to 100 μm. In some examples, the sintered bilayer has a thickness of 20 μm to 100 μm. In some examples, the sintered bilayer has a thickness of 40 μm to 100 μm. In some examples, the sintered bilayer has a thickness of 20 μm to 80 μm. In some examples, the sintered bilayer has a thickness of 40 μm to 80 μm. In some examples, the sintered bilayer has a thickness of 20 μm to 60 μm. In some examples, the sintered bilayer has a thickness of 10 μm to 50 μm. In some examples, the sintered bilayer has a thickness of 10 μm to 40 μm. In some examples, the sintered bilayer has a thickness of 10 μm to 30 μm. In some examples, the sintered bilayer has a thickness of about 10 μm. In some examples, the sintered bilayer has a thickness of about 11 μm. In some examples, the sintered bilayer has a thickness of about 12 μm. In some examples, the sintered bilayer has a thickness of about 13 μm. In some examples, the thickness of the sintered bilayer is about 14 μm. In some examples, the thickness of the sintered bilayer is about 15 μm. In some examples, the thickness of the sintered bilayer is about 16 μm. In some examples, the thickness of the sintered bilayer is about 17 μm. In some examples, the thickness of the sintered bilayer is about 18 μm. In some examples, the thickness of the sintered bilayer is about 19 μm. In some examples, the thickness of the sintered bilayer is about 20 μm. In some examples, the thickness of the sintered bilayer is about 21 μm. In some examples, the thickness of the sintered bilayer is about 22 μm. In some examples, the thickness of the sintered bilayer is about 23 μm. In some examples, the thickness of the sintered bilayer is about 24 μm. In some examples, the thickness of the sintered bilayer is about 25 μm. In some examples, the thickness of the sintered bilayer is about 26 μm. In some examples, the thickness of the sintered bilayer is about 27 μm. In some examples, the thickness of the sintered bilayer is about 28 μm. In some examples, the thickness of the sintered bilayer is about 29 μm. In some examples, the thickness of the sintered bilayer is about 30 μm. In some examples, the thickness of the sintered bilayer is about 31 μm. In some examples, the thickness of the sintered bilayer is about 32 μm. In some examples, the thickness of the sintered bilayer is about 33 μm. In some examples, the thickness of the sintered bilayer is about 34 μm. In some examples, the thickness of the sintered bilayer is about 35 μm.In some examples, the thickness of the sintered bilayer is about 36 μm. In some examples, the thickness of the sintered bilayer is about 37 μm. In some examples, the thickness of the sintered bilayer is about 38 μm. In some examples, the thickness of the sintered bilayer is about 39 μm. In some examples, the thickness of the sintered bilayer is about 40 μm. In some examples, the maximum thickness of the sintered bilayer is about 40 μm.

[0122] In some embodiments, when the solid electrolyte is sintered, the height of the film (along the z-axis) decreases, while the width and length of the film (along the x-axis and y-axis, respectively) remain approximately constant. In some embodiments, the film may shrink by about 30 to about 40 percent as a result of sintering. Thus, for example, for a film having a film thickness of about 100 μm, the thickness of the sintered film may be about 60 μm to about 70 μm.

[0123] In some examples, the dimensions of the solid electrolyte can be about 64 mm by about 79 mm. In some examples, the dimensions of the solid electrolyte can be about (64±x) mm by about (79.5±y) mm, where x and y are between 1 and 10 mm.

[0124] The processes and apparatus disclosed herein can be used to sinter lithium-filled garnets on metal foils. In some examples, the metal foil is a dense metal layer. In certain examples, the metal foil is a dense metal layer that may also include a ceramic. In some of these examples, the ceramic is a lithium-filled garnet.

[0125] In certain examples, lithium filled garnet (LLZO) is sintered onto a metal foil. In some of these examples, the metal foil is pure Ni. In some of these examples, the metal foil is a combination of Ni and Fe. In some of these examples, the metal foil has a Ni concentration of 85-95% and an Fe concentration of 5-20%. In some of these examples, the metal foil has a Ni concentration of 90-95% and an Fe concentration of 5-10%. In some of these examples, the metal foil is Ni / Fe 93% / 7%. In some of these examples, the metal foil is Ni / Fe 95% / 5%. In some of these examples, the metal foil is Ni / Fe 97% / 3%.

[0126] In certain examples, the LLZO is sintered onto a metal foil. In some of these examples, the metal foil is pure Cu. In some of these examples, the metal foil is Cu / Fe 93% / 7%. In some of these examples, the metal foil is a combination of Cu and Fe.

[0127] In some examples, including any of the foregoing, the sintered article comprises a bilayer. In some examples, the bilayer comprises a metal foil and a ceramic thin film. In some examples, the sintered article comprises a triple layer. In some examples, the metal is Ni. In some examples, the Ni thickness is about 1 μm. In some examples, the Ni thickness is about 2 μm. In some examples, the Ni thickness is about 3 μm. In some examples, the Ni thickness is about 4 μm. In some examples, the Ni thickness is about 5 μm. In some examples, the Ni thickness is about 6 μm. In some examples, the Ni thickness is about 7 μm. In some examples, the Ni thickness is about 8 μm. In some examples, the Ni thickness is about 9 μm. In some examples, the Ni thickness is about 10 μm. In some examples, the Ni thickness is about 11 μm. In some examples, the Ni thickness is about 12 μm. In some examples, the Ni thickness is about 13 μm. In some examples, the Ni thickness is about 14 μm. In some examples, the Ni thickness is about 15 μm. In some examples, the Ni thickness is about 16 μm. In some examples, the Ni thickness is about 17 μm. In some examples, the Ni thickness is about 18 μm. In some examples, the Ni thickness is about 19 μm. In some examples, the Ni thickness is about 20 μm.

[0128] In some examples, the slurry can be deposited onto a sheet of foil to form a foil-backed green tape. In some examples, the foil is a Mylar foil. The foil-backed green tape can be wound into a roll to form a roll of foil-backed unsintered thin film. The roll of foil-backed unsintered thin film can be loaded into an apparatus as described herein. In some examples, a method of using the apparatus can include: (a) loading a roll of foil-backed unsintered thin film onto a front roller, (b) unrolling the unsintered thin film, (c) sintering the unsintered thin film to produce a foil-backed sintered thin film, and (d) winding the foil-backed sintered thin film onto an end roller, these operations being performed in a controlled atmosphere. In some examples, the foil backing can include nickel metal or nickel foil.

[0129] In some instances, the green thin film sintered using the apparatus is a bilayer or trilayer.

[0130] In some examples, various layer structures are contemplated and can be sintered according to the sintering methods described herein: (A) a free-standing lithium-filled garnet material; (B) a free-standing lithium-filled garnet material optionally including an active material, a binder, a solvent, and / or carbon; (C) a bilayer having one layer of lithium-filled garnet and one layer of a metal powder, foil, or sheet; (D) a bilayer having one layer of lithium-filled garnet and one layer including a metal powder, foil, or sheet; (E) a bilayer having one layer of lithium-filled garnet material optionally including an active material, a binder, a solvent, and / or carbon and one layer of a metal powder, foil, or sheet. (F) a trilayer having two layers of lithium filled garnet and a layer of metal powder, foil, or sheet between and in contact with the garnet layers; (G) a trilayer having two layers of lithium filled garnet and a layer of metal powder, foil, or sheet between and in contact with the garnet layers; and (H) a trilayer having two layers of lithium filled garnet material, each garnet layer optionally including active material, binder, solvent, and / or carbon, and a layer of metal powder, foil, or sheet between and in contact with the garnet layers.

[0131] In some cases, the bilayer can be sintered using the apparatus described herein. In some cases, the trilayer can be sintered using the CML described herein.

[0132] The tri-layer may include a lithium-filled garnet layer, a metal layer, and a second layer of lithium-filled garnet opposite the metal layer. The tri-layer thin film may be passed through a device with the lithium-filled garnet layer facing up and the second layer of lithium-filled garnet facing down.

[0133] The bilayer may include a lithium-filled garnet layer and a metal foil layer. The bilayer film may be passed through the device with the lithium-filled garnet layer facing up (i.e., the metal layer on the bottom) or the lithium-filled garnet layer facing down (i.e., the metal layer on top).

[0134] In one embodiment, the foil on which material 130 (in one embodiment, lithium filled garnet) is disposed may be a metal or metal alloy selected from the group consisting of nickel, iron, molybdenum, titanium, tungsten, and copper, and alloys and combinations thereof.

[0135] In some examples, the metal foil or layer is nickel, steel, stainless steel, copper, iron, aluminum, titanium, tungsten, molybdenum, Kovar, Invar, ceramic, Haynes 216, or combinations thereof.

[0136] In some examples, the metal layer includes Ni, Fe, Cu, Al, Sn, Mo, steel, an alloy, or a combination thereof. For example, the metal layer may include Ni and Fe. For example, the metal layer may include about 70% Ni and about 30% Fe. For example, the metal layer may include Ni and Fe. For example, the metal layer may include about 80% Ni and about 20% Fe. For example, the metal layer may include Ni and Fe. For example, the metal layer may include about 90% Ni and about 10% Fe. For example, the metal layer may include about 91% Ni and about 9% Fe. For example, the metal layer may include about 92% Ni and about 8% Fe. For example, the metal layer may include about 93% Ni and about 7% Fe. For example, the metal layer may include about 94% Ni and about 6% Fe. For example, the metal layer may include about 95% Ni and about 5% Fe. For example, the metal layer may include about 96% Ni and about 4% Fe. For example, the metal layer may include about 97% Ni and about 3% Fe. For example, the metal layer may include about 98% Ni and about 2% Fe. For example, the metal layer may include about 99% Ni and about 1% Fe. In some examples, the metal layer is a sheet of metal. In some examples, the metal layer is a sheet of aluminum. In some examples, the metal layer is a sheet of nickel. In some examples, the metal layer may be malleable.

[0137] For example, the metal layer may contain up to 20% Fe. Figure 16 shows an example of a thin film formed according to one embodiment where the amount of Fe in the Ni / Fe alloy foil is greater than 20%.

[0138] In some examples, the thickness of the metal layer is about 1 μm. In some examples, the thickness of the metal layer is about 2 μm. In some examples, the thickness of the metal layer is about 3 μm. In some examples, the thickness of the metal layer is about 4 μm. In some examples, the thickness of the metal layer is about 5 μm. In some examples, the thickness of the metal layer is about 6 μm. In some examples, the thickness of the metal layer is about 7 μm. In some examples, the thickness of the metal layer is about 8 μm. In some examples, the thickness of the metal layer is about 9 μm. In some examples, the thickness of the metal layer is about 10 μm. In some examples, the thickness of the metal layer is about 11 μm. In some examples, the thickness of the metal layer is about 12 μm. In some examples, the thickness of the metal layer is about 13 μm. In some examples, the thickness of the metal layer is about 14 μm. In some examples, the thickness of the metal layer is about 15 μm. In some examples, the thickness of the metal layer is about 16 μm. In some examples, the thickness of the metal layer is about 17 μm. In some examples, the thickness of the metal layer is about 18 μm. In some examples, the thickness of the metal layer is about 19 μm. In some examples, the metal layer has a thickness of about 20 μm. In some examples, the metal layer is formed by electrodeposition. In some examples, the metal layer is formed by roll annealing. In some examples, the metal layer is a bilayer of two metals. In some examples, the metal bilayer can be formed by electrodeposition, sputtering, or vapor deposition of a top metal layer onto a metal foil.

[0139] In some examples, the lithium-filled garnet-metal sintered thin films herein have a thickness of about 1 μm to about 100 μm. In certain examples, these thin films are co-sintered with mixed amounts of lithium-filled garnet and metal. The metal can be selected from the group consisting of Ni, Mg, Li, Fe, Al, Cu, Mo, Ti, steel, alloys thereof, and combinations thereof. The lithium-filled garnet and metal are mixed as powders and then co-sintered to form the thin film. In some examples, the thin film comprises a homogenous mixture of lithium-filled garnet and metal. The relative amounts of lithium-filled garnet and metal can vary from about 1% by volume lithium-filled garnet up to about 99% by volume lithium-filled garnet, with the remainder being metal.

[0140] In some examples, including any of the above, the lithium-filled garnet is sintered onto the ceramic metal film.

[0141] In some embodiments, the materials described herein may be subjected to sintering within a process window, which may be defined as the window in which a material such as lithium loaded garnet may be sintered without forming substantial domains and with suitable porosity. In some embodiments, variables that may be used to define a suitable process window may relate to the furnace profile in which the sintering is accomplished and the formulation being sintered. These variables are, among others: Furnace profile: Sintering temperature Sintering ramp rate Sintering residence time (total time in one or more specific zones and / or in the furnace) ·BBO temperature BBO Ramp Rate BBO residence time (total time in one or more specific zones and / or in the furnace) ·Cooling rate Formulation: Unsintered density Powder batch Ceramic grain size

[0142] Looking at the furnace profile, in some embodiments, there may be a set of parameters that may be part of what defines a process window where sintering can be successful with little or no domain formation and adequate porosity (in some embodiments, less than 1 percent). In some embodiments, various combinations of sintering residence times and ramp rates may define the process window. In different embodiments, the sintering residence time may vary from 1 to 10 minutes and the ramp rate may vary from 6° C. to 24° C. / min. In different embodiments, the sintering residence time may be 1 minute and the ramp rate may vary from 6° C. to 24° C. / min. In different embodiments, the sintering residence time may be 2 minutes and the ramp rate may vary from 6° C. to 24° C. / min. In different embodiments, the sintering residence time may be 3 minutes and the ramp rate may vary from 6° C. to 24° C. / min. In different embodiments, the sintering residence time may be 4 minutes and the ramp rate may vary from 6° C. to 24° C. / min. In different embodiments, the sintering residence time can be 5 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 6 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 7 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 8 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 9 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 10 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 1 minute and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 2 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 3 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 4 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 5 minutes and the ramp rate can vary from 6°C to 24°C / min.In different embodiments, the sintering residence time can be 6 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 7 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 8 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 9 minutes and the ramp rate can vary from 6°C to 24°C / min. In different embodiments, the sintering residence time can be 10 minutes and the ramp rate can vary from 6°C to 24°C / min.

[0143] For each of the sintering residence times just mentioned, in some embodiments the ramp rate can be at least 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 50°C, 75°C, 100°C, 125°C, 150°C, 175°C, or 200°C / min. In some embodiments, depending on the equipment, ramp rates of at least 25°C / min, 50°C / min, 75°C / min, 100°C / min, 125°C / min, or 150°C / min can be used. As one of ordinary skill in the art will appreciate, varying the ramp rate will affect several other factors of the process, such as sintering residence time, gas flow rates, fixtures, etc.

[0144] 17 shows a film produced according to one embodiment using a ramp rate of 10° C. / min to 1,160° C. and a dwell time of 5 minutes at 1,160° C. As can be seen, the film has large pores and domains formed, likely due to the slow ramp rate under these conditions.

[0145] In the processes described herein, different tools may require different gas residence times. The gas residence time may be as short as 1 minute or as long as 20 minutes. In some cases, the gas residence time is between 2 minutes and 15 minutes, between 4 minutes and 13 minutes, or between 4 minutes and 10 minutes.

[0146] As one skilled in the art will appreciate, to improve control of granularity, residence times can be in the order of seconds instead of minutes and / or the ratio of ramp rates can be greater.

[0147] In some embodiments, the shorter the residence time, the faster the conveyor speed can be. In the case of a multi-region furnace, in some embodiments, the longer each zone, the faster the conveyor can move for a given residence time.

[0148] In some embodiments, sintering can occur within one or more particular zones of the furnace. In some embodiments, sintering can occur within a portion of a particular zone of the furnace.

[0149] In different embodiments, the range of speeds at which the bilayer structure can pass through the various zones of the furnace can be between 20 mm / min and 150 mm / min, depending on the length of the zones, residence time, and ramp rate. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 25 mm / min and 145 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 30 mm / min and 140 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 35 mm / min and 135 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 40 mm / min and 130 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 45 mm / min and 125 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 50 mm / min and 120 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 60 mm / min and 110 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 65 mm / min and 105 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 70 mm / min and 100 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 75 mm / min and 95 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 70 mm / min and 90 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 75 mm / min and 95 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 75 mm / min and 95 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 80 mm / min and 90 mm / min.

[0150] In different embodiments, the range of speeds at which the bilayer structure can pass through the various zones of the furnace can be between 20 mm / min and 100 mm / min, depending on the length of the zones, residence time, and ramp rate. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 25 mm / min and 95 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 30 mm / min and 90 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 35 mm / min and 85 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 40 mm / min and 80 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 45 mm / min and 75 mm / min. In different embodiments, the bilayer structure can pass through the various zones of the furnace at a speed between 50 mm / min and 70 mm / min. In different embodiments, the dual layer structure can be passed through various zones of the furnace at speeds between 55 mm / min and 65 mm / min.

[0151] In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 50 mm / min and 100 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 55 mm / min and 95 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 60 mm / min and 90 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 65 mm / min and 85 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 70 mm / min and 80 mm / min.

[0152] In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed between 50 mm / min and 80 mm / min. In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed between 55 mm / min and 75 mm / min. In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed between 60 mm / min and 70 mm / min.

[0153] In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 20 mm / min and 80 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 25 mm / min and 75 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 30 mm / min and 70 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 35 mm / min and 65 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 40 mm / min and 60 mm / min. In different embodiments, the double layer structure can be passed through the various zones of the furnace at a speed between 45 mm / min and 55 mm / min.

[0154] In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed of 20 mm / min to 30 mm / min. In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed of 25 mm / min to 35 mm / min. In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed of 30 mm / min to 40 mm / min. In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed of 35 mm / min to 45 mm / min. In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed of 40 mm / min to 50 mm / min. In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed of 50 mm / min to 60 mm / min. In different embodiments, the bilayer structure can be passed through the various zones of the furnace at a speed of 55 mm / min to 65 mm / min. In different embodiments, the dual layer structure can be passed through various zones of the furnace at speeds between 75 mm / min and 85 mm / min.

[0155] The devices, systems, and processes described herein are useful for the production of a variety of materials, including but not limited to lithium-filled garnet thin films, including but not limited to bilayers with a lithium-filled garnet thin film on a metal layer, or trilayers with a metal layer between two lithium-filled garnet thin films.The apparatus, systems, and processes described herein are not limited to, and may be implemented in accordance with, any of the following applications: International Application No. PCT / US2016 / 043428, filed July 21, 2016 and published as WO 2017015511A1, entitled "PROCESSES AND MATERIALS FOR CASTING AND SINTERING GREEN GARNET THIN FILMS"; International Application No. PCT / US2019 / 056584, filed October 16, 2019 and published as WO 2020081718A1, entitled "SINTERING LARGE AREA CERAMIC ... and International Application No. PCT / US2019 / 056584, filed October 16, 2019 and published as WO 2020081718A1, entitled "SINTERING LARGE AREA CERAMIC THIN FILMS"; No. PCT / US2016 / 15209, filed on January 27, 2016 and published as WO 2017131676A1, entitled "ANNEALED GARNET ELECTROLYTE SEPARATORS"; No. PCT / US2017 / 039069, filed on January 23, 2017 and published as WO 2018236394A1, entitled "LITHIUM-STUFFED GARNET ELECTROLYTES WITH SECONDARY PHASE INCLUSIONS" No. PCT / US2019 / 54117, filed on October 1, 2019, and published as WO 2020072524A1, entitled METHODS OF MAKING AND USING AN ELECTROCHEMICAL CELL COMPRISING AN INTERLAYER; useful for making lithium-filled garnet thin films or composites, including, but not limited to, any of the sintered thin films or thin film-containing materials described in U.S. Pat. Nos. 10,403,931; 10,290,895; 9,966,630 B2; 10,347,937 B2; and 10,103,405.

[0156] In some examples, including any of the foregoing, the ceramic-metal thin film can be an oxide-metal thin film. In some examples, the thin film has one layer that is ceramic and one layer that is metal. In other examples, the thin film is a homogenous mixture of ceramic and metal. In some examples, the ceramic-metal thin film includes ceramic and metal. In some examples, the volume percent of the ceramic is about 10% and the volume percent of the metal is about 90%. In some examples, the volume percent of the ceramic is about 20% and the volume percent of the metal is about 80%. In some examples, the volume percent of the ceramic is about 30% and the volume percent of the metal is about 70%. In some examples, the volume percent of the ceramic is about 40% and the volume percent of the metal is about 60%. In some examples, the volume percent of the ceramic is about 50% and the volume percent of the metal is about 50%. In some examples, the volume percent of the ceramic is about 60% and the volume percent of the metal is about 40%. In some examples, the volume percent of the ceramic is about 70% and the volume percent of the metal is about 30%. In some examples, the volume percent of ceramic is about 80% and the volume percent of metal is about 20%. In some examples, the volume percent of ceramic is about 90% and the volume percent of metal is about 10%. In some examples, the volume percent of ceramic is about 5% and the volume percent of metal is about 95%. In some examples, the volume percent of ceramic is about 15% and the volume percent of metal is about 85%. In some examples, the volume percent of ceramic is about 25% and the volume percent of metal is about 75%. In some examples, the volume percent of ceramic is about 35% and the volume percent of metal is about 65%. In some examples, the volume percent of ceramic is about 45% and the volume percent of metal is about 55%. In some examples, the volume percent of ceramic is about 55% and the volume percent of metal is about 45%. In some examples, the volume percent of ceramic is about 65% and the volume percent of metal is about 35%. In some examples, the volume percent of ceramic is about 75% and the volume percent of metal is about 25%.In some examples, the volume percent of ceramic is about 85% and the volume percent of metal is about 15%. In some examples, the volume percent of ceramic is about 95% and the volume percent of metal is about 5%.

[0157] In some examples, including any of the foregoing, the ceramic-metal thin film includes an oxide and a metal. In some examples, the volume percent of the oxide is about 10% and the volume percent of the metal is about 90%. In some examples, the volume percent of the oxide is about 20% and the volume percent of the metal is about 80%. In some examples, the volume percent of the oxide is about 30% and the volume percent of the metal is about 70%. In some examples, the volume percent of the oxide is about 40% and the volume percent of the metal is about 60%. In some examples, the volume percent of the oxide is about 50% and the volume percent of the metal is about 50%. In some examples, the volume percent of the oxide is about 60% and the volume percent of the metal is about 40%. In some examples, the volume percent of the oxide is about 70% and the volume percent of the metal is about 30%. In some examples, the volume percent of the oxide is about 80% and the volume percent of the metal is about 20%. In some examples, the volume percent of the oxide is about 90% and the volume percent of the metal is about 10%. In some examples, the volume percent of oxide is about 5% and the volume percent of metal is about 95%. In some examples, the volume percent of oxide is about 15% and the volume percent of metal is about 85%. In some examples, the volume percent of oxide is about 25% and the volume percent of metal is about 75%. In some examples, the volume percent of oxide is about 35% and the volume percent of metal is about 65%. In some examples, the volume percent of oxide is about 45% and the volume percent of metal is about 55%. In some examples, the volume percent of oxide is about 55% and the volume percent of metal is about 45%. In some examples, the volume percent of oxide is about 65% and the volume percent of metal is about 32%. In some examples, the volume percent of oxide is about 75% and the volume percent of metal is about 25%. In some examples, the volume percent of oxide is about 85% and the volume percent of metal is about 15%. In some examples, the volume percent of oxide is about 95% and the volume percent of metal is about 5%.

[0158] In some examples, including any of the foregoing, the ceramic-metal thin film comprises a ceramic and a metal. In some examples, the weight percent of the ceramic is about 10% and the weight percent of the metal is about 90%. In some examples, the weight percent of the ceramic is about 20% and the weight percent of the metal is about 80%. In some examples, the weight percent of the ceramic is about 30% and the weight percent of the metal is about 70%. In some examples, the weight percent of the ceramic is about 40% and the weight percent of the metal is about 60%. In some examples, the weight percent of the ceramic is about 50% and the weight percent of the metal is about 50%. In some examples, the weight percent of the ceramic is about 60% and the weight percent of the metal is about 40%. In some examples, the weight percent of the ceramic is about 70% and the weight percent of the metal is about 30%. In some examples, the weight percent of the ceramic is about 80% and the weight percent of the metal is about 20%. In some examples, the weight percent of the ceramic is about 90% and the weight percent of the metal is about 10%. In some examples, the weight percent of the ceramic is about 5% and the weight percent of the metal is about 95%. In some examples, the weight percent of the ceramic is about 15% and the weight percent of the metal is about 85%. In some examples, the weight percent of the ceramic is about 25% and the weight percent of the metal is about 75%. In some examples, the weight percent of the ceramic is about 35% and the weight percent of the metal is about 65%. In some examples, the weight percent of the ceramic is about 45% and the weight percent of the metal is about 55%. In some examples, the weight percent of the ceramic is about 55% and the weight percent of the metal is about 45%. In some examples, the weight percent of the ceramic is about 65% and the weight percent of the metal is about 35%. In some examples, the weight percent of the ceramic is about 75% and the weight percent of the metal is about 25%. In some examples, the weight percent of the ceramic is about 85% and the weight percent of the metal is about 15%. In some examples, the weight percent of the ceramic is about 95% and the weight percent of the metal is about 5%.

[0159] In some examples, including any of the foregoing, the ceramic in the ceramic-metal thin film can be alumina, silica, titania, lithium-loaded garnet, lithium aluminate, aluminum hydroxide, aluminosilicate, lithium zirconate, lanthanum aluminate, lanthanum zirconate, lanthanum oxide, lithium lanthanum oxide, zirconia, Li 2 ZrO 3 , xLi 2 O-(1-x)SiO 2 (in the formula, x=0.01~0.99), aLi 2 O-bB 2 O 3 -cSiO 2 (in the formula, a+b+c=1), LiLaO 2 , LiAlO 2 , Li 2 O, Li 3 PO 4 , or a combination thereof.

[0160] In examples, the triple layer includes a metal foil and an unsintered ceramic thin film on either side of the metal foil. The thickness of the metal foil in the double or triple layer can be from 0.5 μm to 50 μm. The thickness of the metal foil in the double or triple layer can be from 3 μm to 30 μm. In some examples, the thickness of the metal foil in the double or triple layer can be from 5 μm to 20 μm. In other examples, the thickness of the metal foil in the double or triple layer can be from 5 μm to 15 μm.

[0161] FIG. 19 shows an embodiment in which the bilayer (B) is sandwiched between a centerless cover (A) and a bottom setter (C). In some embodiments, the centerless cover (A) is a top setter. In some embodiments, the centerless cover (A) is a foam material. In some embodiments, including any of the above, the bilayer (B) comprises one layer comprising a metal and a second layer comprising an unsintered or sintered thin film. In some embodiments, the sintered thin film of the bilayer (B) is a lithium-filled garnet sintered thin film. In some embodiments, including any of the above, the metal-containing layer of the bilayer (B) further comprises lithium-filled garnet. In some embodiments, including any of the above, the metal-containing layer comprises nickel (Ni). In some embodiments, including any of the above, the metal-containing layer comprises copper (Cu). In some embodiments, including any of the above, the metal-containing layer comprises iron (Fe). In some embodiments, including any of the above, the foam material is a metal foam. In some embodiments, including any of the above, the foam material is a porous nickel foam. EXAMPLES

[0162] Working Example Reagents, chemicals, and materials were purchased commercially unless otherwise indicated.

[0163] The pouch cell containers were purchased from Showa Denko.

[0164] The electrochemical potentiostat used was an Arbin potentiostat.

[0165] Electrical impedance spectroscopy (EIS) was performed using a Biologic VMP3, VSP, VSP-300, SP-150, or SP-200.

[0166] Scanning electron microscopy (SEM) was performed using an FEI Quanta SEM, Apreo SEM, Helios 600i, or Helios 660 FIB-SEM (FIB stands for Focused Ion Beam).

[0167] Transmission electron microscopy (TEM) was performed as follows.

[0168] Sample preparation: Samples for TEM measurements were prepared using a Ga ion source focused ion beam SEM (Hitachi High Technologies nanoDUET NB5000). To protect the surface of the material from the Ga ion beam, multiple protective layers were deposited before sampling; first, a metal layer was deposited by a plasma coater, and then a carbon protective layer and a tungsten layer were deposited by high vacuum evaporation and focused ion beam methods, respectively. Sampling of the thin sections was performed by focused ion beam. The prepared samples were measured by a transmission electron microscope.

[0169] Powder X-ray diffraction (XRD) was performed on a Bruker D8 Advance A25 using Cu K-α radiation at room temperature (e.g., 21 °C to 23 °C). The light source was Cu-Ka, with a wavelength of 1.54 Å (1.54 × 10 -10 The power output was 100 Hz (100 Hz). The X-rays were at 40 kV and 25 mA. The detector was a Bruker LYNXEYE XE with a position sensitive detector (PSD) aperture of 2.843. The divergence slit was 0.6 mm and the anti-scatter was fixed at 5.0 mm.

[0170] Milling was performed using a Retsch PM 400 Planetary Ball Mill. Mixing was performed using a Fisher Scientific vortex mixer, a Flaktek speed mixer, or a Primix filmix homogenizer.

[0171] Casting was performed on a TQC drawdown table. Calendering was performed on an Innovative Machines Corporation (IMC) calender.

[0172] Figure 9 shows two membranes formed in accordance with an embodiment. The membrane on the left has dimensions of approximately 60mm x 75mm. The membrane on the right has dimensions of approximately 75mm x 90mm.

[0173] Example 1 - RTP process The green tape cast on the metal foil was unrolled and cut to dimensions suitable for sintering. This was done using a laser cutter, but in different iterations it could also be cut using a blade blanking tool. The individual green sheets were then stacked between setter elements and placed on a bottom graphite heating plate that is part of the sintering apparatus, with a top graphite heating plate closely spaced above it. In this case the setter elements were made of high density Al 2 O 3 High density Al plate 2 O 3 On top of the plate, the green sheet is placed coated side up, followed by a ceramic or metal frame element, followed by another high density Al 2 O 3 The plates are placed.

[0174] The stack was heated to 800 °C at a ramp rate of 50 °C / min (range: 50 °C / min to 100 °C / min) and held for 5 minutes. The gas flow rate was 2.0 LPM (liters per minute), mostly argon gas. After removing the organics, the stack was heated to 1,100 °C at a ramp rate of 100 °C / min (range: 100 °C / min to 300 °C / min) for sintering and held for 30 seconds. The graphite plate was then cooled to room temperature at 100 °C / min (range: 100 °C / min to 300 °C / min). Once at room temperature, the sintered stack was removed from the furnace and disassembled.

[0175] Example 2 - Two-Step Process (RTP Fixture Followed by Lamp Fixture) As described above, the green tape cast on the metal foil was unrolled and cut to dimensions suitable for sintering. This was done using a laser cutter, but in different iterations it could also be cut using a die cutter. The individual green sheets were then stacked between setter elements and placed on a bottom graphite heating plate that is part of a debinding apparatus, with a top graphite heating plate closely spaced above it. In this case the setter elements were made of high density Al 2 O 3 High density Al plate 2 O 3 On top of the plate, the green sheet is placed coated side up, followed by a ceramic or metal frame element, followed by another high density Al 2 O 3 The plates are placed.

[0176] To remove organics from the green layer, the graphite plate was heated to 800°C at a ramp rate of 50°C / min (range: 50°C / min to 100°C / min) and held for 5 minutes. The graphite plate was then cooled to room temperature at 100°C / min (range: 100°C / min to 300°C / min). Once at room temperature, the sintered stack was removed from the graphite plate and transferred to a lamp heating system for sintering, where the sintered stack was placed on a graphite susceptor.

[0177] In the ramp heating system, the gas flow rate was 0.25 LPM (liters per minute), mostly argon gas. For sintering, the graphite susceptor containing the sintered stack was heated to 1,120 °C (range: 1,080 °C to 1,120 °C) at a ramp rate of 300 °C / min and held for 30 seconds (range: 30 seconds to 2 minutes). Once at room temperature, the sintered stack was removed from the heating system and disassembled.

[0178] Example 3 - Vacuum Furnace Equipment As described above, the green tape cast on the metal foil was unrolled and cut to dimensions suitable for sintering. This was done using a laser cutter, but in different iterations it could also be cut using a die cutter. The individual green sheets were then stacked between setter elements and placed in the support fixture used in the sintering machine. In this case the setter elements were made of high density Al 2 O 3 High density Al plate 2 O 3 On top of the plate, the green sheet is placed with the coating side up, followed by a ceramic or metal frame element, followed by LiAlO 2 The coated metal sheet is placed, followed by another high-density Al 2 O 3 The plates are placed.

[0179] The fabricated sintered stack, including the support fixture, setter elements, and individual green sheets, was placed in a vacuum furnace. To remove organics from the green layers, the furnace was heated to 780°C (range: 760°C-840°C) at atmospheric pressure with a ramp rate of 30°C / min (range: 10°C / min-30°C / min) and held for 15 minutes. The gas flow rate was 5.0 LPM (liters per minute) (range: 5 LPM-13 LPM), mostly nitrogen gas. After removing the organics, the furnace was heated to approximately 1,200°C with a ramp rate of 50°C / min for sintering and held for 1 minute. The furnace was then cooled to room temperature. Once at room temperature, the sintered stack was removed from the furnace and disassembled. A cross section of the resulting thin film is shown in FIG. 18.

[0180] Example 4 - Vacuum Furnace Process Under Partial Vacuum As described above, the green tape cast on the metal foil was unrolled and cut to dimensions suitable for sintering. This was done using a laser cutter, but in different iterations it could also be cut using a die cutter. The individual green sheets were then stacked between setter elements and placed in the support fixture used in the sintering machine. In this case the setter elements were made of high density Al 2 O 3 High density Al plate2 O 3 On top of the plate, the green sheet is placed with the coating side up, followed by a ceramic or metal frame element, followed by LiAlO 2 The coated metal sheet is placed, followed by another high-density Al 2 O 3 The plates are placed.

[0181] The fabricated sintered stack, including the support fixture, setter elements, and individual green sheets, was placed in a vacuum furnace. To remove organics from the green layers, the furnace was heated to approximately 800° C. at atmospheric pressure and held for 15 minutes. The gas flow rate was 5.0 LPM (liters per minute), mostly nitrogen gas. After the organics were removed, the furnace was cooled to room temperature. Once at room temperature, the furnace was pumped at a pumping speed of approximately 15 m / s with 5.0 LPM of nitrogen until the pressure reached 14 Torr. 3 A partial vacuum was created in the furnace by pumping with a dry vacuum pump for 100 rpm / hr. Maintaining this condition throughout, the furnace was heated to approximately 1150°C at a ramp rate of 50°C / min and held for 1 minute for sintering. The furnace was then cooled to room temperature. Once at room temperature, pumping was stopped, the furnace was vented to atmospheric pressure with nitrogen, and the sintered stack was removed from the furnace and disassembled.

[0182] Example 5 The fabricated sintered stack, including the support fixture, setter elements, and individual green sheets, was placed on the conveyor of the RHK (Roller Hearth Kiln). The temperature profile of the RHK was specified to perform two steps. To remove the organics from the green layer, the sintered stack was heated to 800°C with an effective ramp rate of 24°C / min and held for 15 minutes. After removing the organics, the sintered stack was heated to 1,150°C with an effective ramp rate of 24°C / min for sintering and held there for 7 minutes. The sintered stack was then cooled to room temperature. Upon exiting the RHK, the sintered stack was removed from the conveyor and disassembled. The sintered film was then cut to a size suitable for the construction of battery cells using a laser cutter. The resulting film was formed into battery cells for electrical testing, as shown in Figures 10 and 11.

[0183] The battery was assembled with two bilayers containing NMC active material. The bilayer thin film was 35 μm thick, 60 mm wide, and 75 mm long. The cathode was infiltrated with liquid catholyte containing lithium salt and a solvent to dissolve the salt. The cell was cycled at 25° C. and 1 atm at a charge rate of 1.35 C and a discharge rate of 1 C. As shown in FIG. 10, the cell maintained more than 90% of its initial capacity after 300 cycles at 100% depth of discharge.

[0184] Example 6 The battery was assembled with six bilayers containing NMC active material. The bilayer thin film was 35 μm thick, 60 mm wide, and 75 mm long. The cathode was infiltrated with liquid catholyte containing lithium salt and a solvent to dissolve the salt. The cell was cycled at 25° C., 1.5 atm, and a charge rate of 1 C and a discharge rate of 1 C. As shown in FIG. 11, the cell maintained more than 95% of its initial capacity after 300 cycles at 100% depth of discharge.

[0185] Example 7 As described above, the green tape cast on the metal foil was unrolled and cut to dimensions suitable for sintering. This was done using a die cutter, but in different iterations, it could also be cut using a laser cutter. The individual green sheets were then stacked between setter elements and placed in the support fixture used in the sintering machine. In this case, the setter elements were made of high density Al 2 O 3 High density Al plate 2 O 3 On top of the plate, the green sheet is placed with the coating side up, followed by a ceramic or metal frame element, followed by LiAlO 2 Another high density Al with coating 2 O 3 The plates are placed.

[0186] Example 8 The fabricated sintered stack, including the support fixture, setter elements, and individual green sheets, was placed in a 3-inch (7.62 cm) tube furnace. To remove organics from the green layer, the furnace was heated to 800° C. at a ramp rate of 10° C. / min and held for 15 minutes. The gas flow rate was 0.25 LPM (liters per minute), mostly nitrogen gas. After removing the organics, the furnace was heated to 1,150° C. at a ramp rate of 10° C. / min and held for 5 minutes for sintering. The furnace was then cooled to room temperature at 10° C. / min until the natural cooling rate of the furnace was reached. Once at room temperature, the sintered stack was removed from the furnace and disassembled. Thin film imaging for domain observation was performed using an optical microscope under coaxial illumination conditions.

[0187] A micrograph of the thin film, Figure 13, shows domains in the thin film, which are large grains and are shown as white spots in Figure 13. In this example, the domains formed because the thin film was sintered at too high a temperature and the residence time of the thin film was too long.

[0188] Example 9 The thin films were formed with a ramp rate of 50°C / min up to 1,100°C and a dwell of 1 minute at the maximum temperature (i.e., 1,100°C). Figure 12 is a micrograph of the resulting thin film, showing pores in the film. In this example, the thin film was sintered at too low a temperature and the dwell time was too short. As one skilled in the art will appreciate, there is a direct correlation between the length of dwell time and the maximum sintering temperature; i.e., increasing one variable directly affects the other variable.

[0189] Example 10 14 shows a cross-section of a green thin film before heat treatment according to one embodiment. The green thin film has a thickness of about 50 μm.

[0190] Figure 15 shows a cross-section of the green thin film of Figure 14 after the heat treatment steps described herein. The thickness of the sintered thin film is about 25 μm.

[0191] Tabletop example: Making a sintered solid electrolyte In the following prophetic example, a lithium loaded garnet, a solvent, a binder, and a plasticizer are mixed to form a slurry.

[0192] Prophetic Example 1 (Slurry 1): LLZO powder was dispersed in ethanol containing 2 wt% polyacrylic acid using an ultrasonic horn. Larger particles were allowed to settle. The supernatant was decanted and the collected powder was dried in air. The collected powder, polyvinyl butyral, benzyl butyl phthalate, acetone, and ethanol were added to a vial in a weight ratio of 37:3:3:29:29 and a 2.0 mm diameter ZrO 2 The films were ball milled with beads for 10-24 hours. The slurry was cast onto a Mylar substrate using a doctor blade; the thickness of the film was controlled by adjusting the height of the blade. The dried unsintered films were manually peeled off the Mylar substrate and cut to the desired size.

[0193] Prophetic Example 2 (Slurry 2): LLZO powder containing 3 wt% polyacrylic acid was dispersed in ethanol. A second solution of polyvinyl butyral, benzyl butyl phthalate, and acetone was mixed in a weight ratio of 1:1:10. The second solution was mixed with the first solution in equal volumes. The resulting slurry was dispersed in ethanol using ZrO 2 The slurry was bead milled for 8-16 hours. The slurry was cast onto a Mylar substrate using a doctor blade with the thickness controlled by the height of the doctor blade. After drying in air, the film was manually peeled off the substrate and cut to size.

[0194] Prophetic Example 3 (Slurry 3): Methylcellulose, polyethylene glycol, and glycerol were dissolved in water to prepare an aqueous polymer solution. The weight ratio of the components was water:(methylcellulose):(polyethylene glycol):glycerol=100:1:4:4. LLZO powder was added to the polymer solution in the same weight as the solution. The slurry was dissolved in water and concentrated to 100% water. 2 The beads were mixed for 5-60 minutes. The slurry was cast onto Mylar foil with a doctor blade; its thickness was controlled by the gap of the doctor blade. After drying in air, the tape was peeled off the Mylar substrate and cut to size.

[0195] Prophetic Example 4 (Slurry 4): LLZO was ball milled in a mixture of equal parts ethanol, xylene, and toluene. Menhaden fish oil, 2-5% by weight relative to LLZO, was added dropwise for 30 minutes. Polyvinyl butyral, 6-10% by weight relative to LLZO, polyethylene glycol, 2-4% by weight relative to LLZO, and benzyl butyl phthalate, 3-7% by weight relative to LLZO, were added and mixed. The tape was cast onto a Mylar substrate with a doctor blade. After drying at 45°C for 1-6 hours, the tape was removed from the Mylar and cut to size.

[0196] Prophetic Example 5 (Slurry 5): 100 g of LLZO powder, 2-4 g of glyceryl trioleate, 100-200 g of n-propyl propionate, and 15-25 g of Elvacite E-2046 were mixed and ball milled to prepare a slurry. The slurry was cast onto a substrate with a doctor blade, dried, and removed from the substrate.

[0197] Prophetic Example 6 (Slurry 6): A slurry was prepared by mixing 20 g of LLZO powder, 25-40 g of a solvent mixture (ethanol:butanol:(propylene glycol) (volume percentages ranging from 70-80:15-25:0-5)), 1-3 g of dibutyl phthalate, 1-4 g of PVB, and 0.1-1 g of a dispersant in a mill. The dispersant can be a dispersant such as Anti-terra-202 from BYK. After mixing, the slurry was filtered, degassed, and cast onto a substrate by reverse comma coating. The green tape was dried, removed from the substrate, and cut to size.

[0198] Prophetic Example 7 (Slurry 7): A slurry was prepared by mixing water (30 parts by weight), LLZO powder (12-18 parts by weight), and binder solution (WB4101, WB40B-44, and WB40B-53 from Polymer Innovations, 8 parts by weight) in a mill for at least 1 hour. After mixing, the slurry was filtered, degassed, and cast onto a substrate by slot die coating. The green tape was dried, removed from the substrate, and cut to size.

[0199] Prophetic Example 8 (Slurry 8): LLZO powder was milled in a solvent mixture of toluene and isopropanol plus fish oil. The mixture was mixed for 1-5 hours to prepare a slurry. A binder solution of polyvinyl butyral and butyl benzyl phthalate was mixed in toluene and isopropanol. The binder solution was added to the slurry and mixed. The mixture was degassed, filtered, and cast onto a polymer carrier. The green tape was dried and blanked into sheets of 10-40 cm length. The blanks were removed from the carrier and then cut to size.

[0200] Prophetic Example 9 (Slurry 9): A slurry of calcined LLZO was prepared by mixing 80 g of calcined LLZO powder with 50 ml of a 33 w / w% polyvinyl butyral solution in toluene and 4 g of plasticizer dibutyl phthalate. A polyacrylic binder was included at 3 weight percent of the solution. The slurry was tape cast onto a silicone-coated Mylar substrate using a doctor blade. The cast mixed slurry was allowed to dry at room temperature for 2-6 hours to form a green thin film. The green thin film was blanked into sheets of 10-40 cm length. The blanks were removed from the carrier and cut to size.

[0201] As mentioned above, in different iterations, the slurry can be cast onto a metal foil, such as Ni foil. As mentioned above, in different iterations, the slurry can be cast onto an alloy foil, such as a combination of nickel, copper, and iron. As mentioned above, in different iterations, the slurry can be cast onto an alloy foil of nickel and iron. In the iterations where the slurry is cast onto a metal foil and dried to form a tape (green bilayer), the green tape layer may or may not be removed from the metal substrate. The slurry on the foil is then placed into an apparatus and sintered.

[0202] After drying, the dried slurry is sintered in the apparatus shown in FIG. 3. In some examples, debinding is performed in-apparatus. In some examples, debinding is performed external to the debinding apparatus. In some examples, the thin films were sintered on a susceptor in an apparatus such as shown in FIG. 3. In some examples, the thin films were sintered directly on a susceptor in an apparatus such as shown in FIG. 3. In some examples, the thin films were sintered in an apparatus such as shown in FIGS. 5 and 8 using fixtures and frame structures such as shown in FIGS. 6A-6C and 7A-7B. FIGS. 4A-4C show sintered samples.

[0203] The above-described embodiments and examples are merely illustrative and are not intended to be limiting. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific compounds, materials, and procedures. All such equivalents are within the scope of the appended claims and are intended to be encompassed therein.

Claims

1. providing a stack comprising a multi-layer body, a fixture, and a frame; wherein the multi-layer body comprises at least one green body layer and at least one metal layer, wherein the green body layers and the metal layers alternate; wherein the fixture comprises a first plate contacting at least one metal layer of the multi-layer body and a second plate disposed on at least one green body layer of the multi-layer body; and wherein the frame is disposed between the at least one green body layer and the second plate; and moving the stack through a furnace at about 1,050°C to about 1,250°C for about 30 seconds to about 3 minutes; thereby providing a sintered multi-layer body comprising at least one ceramic layer and at least one metallic layer; A sintering method comprising:

2. 10. The method of claim 1, wherein moving the stack through the furnace comprises heating the stack in the furnace at a ramp rate of up to about 100°C / min or at a ramp rate of from about 5°C to about 35°C / min.

3. The method of claim 1 , wherein the multilayer body moves through the furnace at a speed of about 20 mm / min to about 80 mm / min.

4. The method of claim 1, wherein the multilayer body remains in the oven for about 1 minute to about 10 minutes.

5. 10. The method of claim 1, further comprising a binder burnout step prior to moving the stack through the furnace, the binder burnout step comprising heating the stack to evaporate organics from the stack.

6. 6. The method of claim 5, wherein the binder burnout step occurs for about 5 seconds to about 5 minutes.

7. The method of claim 5 , wherein the multilayer body includes at least one of a solvent, a binder, a dispersant, a plasticizer, a surfactant, or a combination thereof prior to the binder burnout step.

8. The method of claim 1 , wherein the metal layer comprises a metal selected from the group consisting of nickel, tungsten, copper, iron, titanium, molybdenum, alloys thereof, and combinations thereof.

9. The method of claim 1 , wherein the multilayer body has a thickness of at least about 10 μm after sintering.

10. The method of claim 1 , wherein the multilayer body has a thickness of about 10 μm to about 40 μm after sintering.

11. The method of claim 1 , wherein one of the at least one metal layers has a thickness of about 3 μm to about 30 μm.

12. The method of claim 1 , wherein one of the at least one green body layers has a thickness of about 1 μm to about 100 μm.

13. The method of claim 1, wherein the multi-layer body has a width of about 50 mm to about 150 mm after sintering.

14. The furnace is filled with argon (Ar) gas, nitrogen (N 2 an atmospheric control system for maintaining an atmosphere within the furnace comprising a fluorine-containing gas, hydrogen gas, forming gas, or a mixture thereof; and The atmosphere control device controls the furnace atmosphere to be less than 500 ppm O 2 or the atmosphere control device maintains the furnace atmosphere to contain less than 250 ppm O 2 10. The method of claim 1, wherein the cellular component is maintained to contain:

15. The first plate is made of alumina (Al 2 O 3 ), zirconium-toughened alumina (ZTA), mullite (3Al 2 O 3 2SiO 2 or 2Al 2 O 3 SiO 2 10. The method of claim 1, wherein the substrate comprises a material selected from the group consisting of aluminum nitride (AlN), aluminum nitride (AlN), and silicon carbide (SiC).

16. The second plate is made of alumina (Al 2 O 3 ), zirconium-toughened alumina (ZTA), mullite (3Al 2 O 3 2SiO 2 or 2Al 2 O 3 SiO 2 2. The method of claim 1, wherein the substrate comprises a material selected from the group consisting of aluminum nitride (AlN), aluminum nitride (AlN), and silicon carbide (SiC).

17. The method of claim 1 , wherein the frame comprises a material selected from the group consisting of porous alumina, zirconia, lithium aluminate, lithium tantalate, alumina, silica, cordierite, Ni, Kovar, and Invar.

18. 2. The method of claim 1, wherein the step of moving the stack through the furnace includes moving the stack through the furnace on a conveyor, the conveyor including a plurality of rollers, the rollers contacting the first plate of the stack.

19. The method of claim 1 , wherein the green body layer comprises a ceramic.

20. A sintered multilayer body produced by the method of claim 1.

Images