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WO-2026096273-A1 - FURNACE SYSTEM, METHODS OF FIRING, AND SINTERED ARTICLE

WO2026096273A1WO 2026096273 A1WO2026096273 A1WO 2026096273A1WO-2026096273-A1

Abstract

A furnace system includes a heater contained in a heating chamber. A green tape is configured to contact a contact material while it is in the heating chamber. In aspects, the contact material includes iridium, osmium, rhenium, or an alloy thereof. Alternatively, the contact material is a lithium metal oxide where the metal is scandium or yttrium. In aspects, the contact material has a melting temperature of 1500°C or more, a gas phase oxygen concentration of 10 -10 atmospheres or more, and a gas phase lithium concentration of 10 -5 atmospheres or less. Methods include firing a green tape containing inorganic crystals by heating the green tape while in contact with the contact material. A sintered article includes a body having grains of inorganic material sintered to one another, where a concentration of iridium, osmium, rhenium on a first major surface is greater than or equal to 1 part-per-trillion.

Inventors

  • BADDING, MICHAEL EDWARD
  • CHEN, YINGHONG
  • Ren, Tianqi
  • SHIBITOV, Molly Emma
  • TANNER, CAMERON WAYNE
  • TEPESCH, PATRICK DAVID
  • WANG, YAN
  • ZIMMERMANN, JAMES WILLIAM

Assignees

  • CORNING INCORPORATED

Dates

Publication Date
20260507
Application Date
20251023
Priority Date
20241101

Claims (20)

  1. 1 . A furnace system comprising: a heater contained in a heating chamber; a first contact surface positioned within the heating chamber, wherein a green tape is configured to contact the first contact surface while the green tape is in the heating chamber, and the first contact surface comprises a contact material having: a melting temperature greater than or equal to 1500°C, a gas phase oxygen concentration greater than or equal to 10' 7 atmospheres that produces a gaseous concentration of an oxide of the contact material of 10' 12 atmospheres at 1200°C in a 1 atmosphere argon environment, and a gas phase lithium concentration less than or equal to 10' 5 atmospheres when the contact material is in contact with a lithium garnet at 1200°C.
  2. 2. The furnace system of claim 1, wherein the contact material comprises one or more of iridium, osmium, rhenium, or an alloy thereof
  3. 3. The furnace system of claim 1, wherein the oxygenated gas phase lithium concentration is less than or equal to 10' 5 atmospheres when the contact material is in contact with a lithium garnet at 1200°C in a 1 atmosphere argon environment of 3% oxygen and 97% argon with less than or equal to 10 Pascals of water vapor.
  4. 4. The furnace system of claim 1 or claim 3, wherein the contact material comprises lithium scandium oxide.
  5. 5. The furnace system of any one of claims 1-4, further comprising a conveyance path extending through the heating chamber, wherein the green tape is configured to contact the first contact surface while the green tape is conveyed along at least a portion of the conveyance path.
  6. 6. The furnace system of claim 5, wherein the first contact surface and the green tape are configured to translate together along at least the portion of the conveyance path.
  7. 7. The furnace system of claim 5, wherein the green tape is configured to translate relative to the first contact surface as the green tape is conveyed through the heating chamber along at least the portion of the conveyance path while the green tape is in contact with the first contact surface.
  8. 8. The furnace system of claim 7, further comprising: a second contact surface, the green tape is configured to contact the second contact surface for another portion of the conveyance path, and the second contact surface comprises a different material than the contact material of the first contact surface, wherein a position of the first contact surface is configured to correspond to a maximum temperature encountered by the green tape whereas a second position of the second contact surface does not correspond to the maximum temperature.
  9. 9. The furnace system of claim 8, wherein a second material forming the second contact surface comprises one or more of platinum, rhodium, alumina, calcium oxide, magnesium oxide, tungsten, or an alloy thereof.
  10. 10. The furnace system of any one of claims 1-9, wherein the first contact surface is an outer surface of an article comprising an additional material coated with the contact material.
  11. 11. The furnace system of claim 8, wherein the additional material comprises one or more of alumina, nickel, tungsten, chromium, mullite, or an alloy thereof.
  12. 12. The furnace system of any one of claims 1-11, wherein: the contact material is non-reactive with lithium garnet at 1000°C in an argon environment for 30 minutes; lithium garnet in contact with the first contact surface at 1000°C in an argon environment for 30 minutes does not stick of the first contact surface; or both.
  13. 13. A furnace system comprising: a heater contained in a heating chamber; and a first contact surface positioned within the heating chamber, wherein a green tape is configured to contact the first contact surface while the green tape is in the heating chamber, and the first contact surface comprises a contact material comprising one or more of iridium, osmium, rhenium, or an alloy thereof.
  14. 14. A furnace system comprising: a heater contained in a heating chamber; and a first contact surface positioned within the heating chamber, wherein a green tape is configured to contact the first contact surface while the green tape is in the heating chamber, and the first contact surface comprises a contact material comprising a lithium metal oxide where the metal is selected from a group consisting of scandia, yttrium, and combinations thereof.
  15. 15. A method of firing a green tape containing inorganic crystals, the method comprising: heating the green tape in an atmosphere to sinter the inorganic crystals and form a sintered tape; and contacting the green tape with a first contact surface during at least part of the heating, wherein the first contact surface comprises a contact material having: a melting temperature greater than or equal to 1500°C, a gas phase oxygen concentration greater than or equal to 10' 7 atmospheres that produces a gaseous concentration of an oxide of the contact material of 10' 12 atmospheres at 1200°C in a 1 atmosphere argon environment, and a gas phase lithium concentration less than or equal to 10' 5 atmospheres when the contact material is in contact with a lithium garnet at 1200°C.
  16. 16. The method of claim 15, wherein: a partial pressure of oxygen in the atmosphere is less than or equal to 10 Pascals; a partial pressure of water vapor in the atmosphere is less than or equal to 10 Pascals; or both
  17. 17. The method of any one of claims 15-16, wherein a partial pressure of carbon dioxide in the atmosphere is less than or equal to 10 Pascals.
  18. 18. The method of any one of claims 15-17, wherein the inorganic crystals are a lithium - containing material.
  19. 19. The method of any one of claims 15-18, further comprising conveying the green tape through a heating chamber during the heating, wherein the green tape contacts the first contact surface during at least a portion of the conveying.
  20. 20. The method of claim 19, wherein the at least a portion of the conveying comprises translating the first contact surface and the green tape together.

Description

ATTORNEY DOCKET NO. SP24-263 FURNACE SYSTEM, METHODS OF FIRING, AND SINTERED ARTICLE CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Serial No. 63/715250 filed on November 1, 2024, and U.S. Provisional Application Serial No. 63/760862 filed on February 20, 2025, the content of which is relied upon and incorporated herein by reference in its entirety. FIELD [0002] The present disclosure relates to a furnace system for forming a sintered article, methods of firing a green tape to form a sintered article, and a sintered article, and more particularly furnace systems having a contact material, methods of firing a green tape in contact with a contact material, and a sintered article having traces of contact with another material. BACKGROUND [0003] Solid-state batteries (SSBs) (e.g., SS lithium (Li) metal batteries based on inorganic solid-state electrolytes (SSEs) (such as garnet-type SSE)) have attracted much attention as they have the potential to achieve higher energy densities. Some lithium metal battery design can include lithium-containing ceramic materials, including lithium garnet. It is known to process such ceramics by firing to sinter together grains of the ceramic material. However, such lithium- containing inorganic materials can be reactive, which can hinder processing of such materials. Consequently, there exists a need for methods and apparatus to sinter lithium-containing inorganic materials with minimal side reactions and/or sticking. SUMMARY [0004] The present disclosure provides furnace systems, methods of heating (e.g., firing, sintering) a green body (e.g., green tape) to produce a sintered article, the resulting sintered article (e.g., solid-state electrolyte), and/or a battery (e.g., solid-state battery) containing the same. The inventors of the present disclosure have unexpectedly discovered (especially in view of the abovestate problem) contact materials that can be used to sinter lithium-containing materials without sticking or other reactions. In aspects, the contact material is non-reactive with the lithium- containing material (e.g., lithium garnet) while being heated at 1000°C in an argon environment for 30 minutes or more (e.g., 30 minutes, 45 minutes, 60 minutes). In aspects, the contact material does not stick to the lithium-containing material (e.g., lithium garnet) after being heated at 1000°C in an argon environment for 30 minutes or more (e.g., 30 minutes, 45 minutes, 60 minutes). In aspects, the contact material can comprise iridium, rhenium, osmium, alloys thereof, or combinations thereof. In aspects, the contact material can exhibit one or more of: a melting temperature greater than or equal to 1500°C; a gas phase oxygen concentration greater than or equal to 10'7 atmospheres that produces a gaseous concentration of the contact material of 10'8 atmospheres at 1200°C in a 1 atmosphere argon environment; and/or a gas phase lithium concentration less than or equal to 1 O'5 atmospheres when the contact material is in contact with a lithium garnet at 1200°C. In aspects, an environment that the green body (e.g., green tape) is heated in can comprise less than or equal to 10 Pascals of oxygen, less than or equal to 10 Pascals of carbon dioxide, and/or less than or equal to 10 Pascals of water vapor, which can reduce an incidence of side reactions and/or sticking. [0005] Lithium -containing materials can be highly reactive, especially when heated at or near sintering temperatures. For example, lithium can volatize from the material being heated, which can change the composition of the resulting article and/or react with another material. Additionally, it has been observed that commonly available refractory materials, including MgO, will react with lithium-containing materials being sintered while in contact with said refractory material. These reactions can occur even at low oxygen partial pressures in the heating chamber. Also, this reaction can result in the lithium-containing material sticking (e.g., bonding) to the refractory material (e.g., MgO), which impedes processing and yield of the sintering process. Similar to MgO, it has been observed that sticking or other reactions occurs when using other materials in contact with the lithium-containing materials being heated, including platinum, alumina, zirconia, silicon carbide, aluminum nitride, and cordierite. Additionally, sticking between the green body being sintered and the contact material can occur due to reactions therebetween. Without wishing to be bound by theory, it is believed that some of these reactions can involve the formation of oxides of material from the contact material and/or the volatilization of material from the contact material, which can be enhanced in the presence of oxygen, especially when the contact material includes or is a metal. Consequently, the contact materials may preferably have a low volat