A solid composition according to the present disclosure is a solid composition for use in forming a solid electrolyte having a crystal phase, containing: at normal temperature and normal pressure, an oxide having a crystal phase different from the crystal phase of the solid electrolyte; a lithium compound; and an oxo acid compound. The oxo acid compound may contain at least one of a nitrate ion and a sulfate ion as an oxo anion.

A compound represented by Formula 1 and having an argyrodite-type crystal structure:

Li.sub.xM1.sub.vPS.sub.yM2.sub.wM3.sub.z  Formula 1

In Formula 1, M1 is at least one metal element of Group 1 to Group 15 of the periodic table, except Li, M2 is SO.sub.n, M3 is at least one element of Group 17 of the periodic table; and 4≤x≤8, 0≤v<1, 3≤y≤7, 0<w<2, 0≤z≤2, and 1.5≤n≤5.

Modular pressurized hotbox for use and substitution in a variety of pressurized electrochemical applications to include reversible solid oxide electrolyzer and fuel cells, energy storage systems, renewable fuel production, solid-state hydrogen pumping and liquefaction, and oxygen transport membranes. This is enabled by mixed electronic and ionic conducting compositions of vanadia-yttria and vanadia-calcia stabilized zirconia and a dry powder method of manufacture for ceramic core stacks.

A scintillator for positron emission tomography is provided. The scintillator includes a garnet compound of a formula of A.sub.3B.sub.2C.sub.3O.sub.12 and an activator ion consisting of cerium. A.sub.3 is A.sub.2X. X consists of at least one lanthanide element. A.sub.2 is selected from the group consisting of (i), (ii), (iii), and any combination thereof, wherein (i) consists of at least one lanthanide element, (ii) consists of at least one group I element selected from the group consisting of Na and K, and (iii) consists of at least one group II element selected from the group consisting of Ca, Sr, and Ba. B.sub.2 consists of Sn, Ti, Hf, Zr, and any combination thereof. C.sub.3 consists of Al, Ga, Li, and any combination thereof. The garnet compound is doped with the activator ion.

Provided are a sulfide-based lithium-argyrodite ion superconductor containing multiple chalcogen elements and a method for preparing the same. More specifically, provided are a sulfide-based lithium-argyrodite ion superconductor containing multiple chalcogen elements and a method for preparing the same that are capable of significantly improving lithium ion conductivity by substituting a sulfur (S) element in a PS.sub.4.sup.3- tetrahedron with a chalcogen element such as a selenium (Se) element, other than the sulfur (S) element, while maintaining an argyrodite-type crystal structure of a sulfide-based solid electrolyte represented by Li.sub.6PS.sub.5Cl.

Provided are solid-state electrolyte structures. The solid-state electrolyte structures are ion-conducting materials. The solid-state electrolyte structures may be formed by 3-D printing using 3-D printable compositions. 3-D printable compositions may include ion-conducting materials and at least one dispersant, a binder, a plasticizer, or a solvent or any combination of one or more dispersant, binder, plasticizer, or solvent. The solid-state electrolyte structures can be used in electrochemical devices.

Disclosed are electrochemical devices, such as lithium battery electrodes, lithium ion conducting solid state electrolytes, and solid-state lithium metal batteries including these electrodes and solid state electrolytes. In one embodiment, a method for forming an electrochemical device is disclosed in which a precursor electrolyte is heated to remove at least a portion of a resistive surface region of the precursor electrolyte.

An intermediate temperature solid oxide fuel cell (IT-SOFC) includes an anode layer, an electrolyte adjacent to the anode layer, and a cathode layer adjacent to the electrolyte and including a material of formula (I) or (II): Sr.sub.2OsO.sub.4 (I) or Ba.sub.2MO.sub.4 (II), where M is a transition metal or post-transition metal.

A method for producing a sulfide solid electrolyte comprising an argyrodite-type crystal structure, wherein phosphorus sulfide having a phosphorus content of 28.3 mass % or less and containing free sulfur is used as the raw material.

A method of manufacturing an argyrodite-type solid electrolyte, an argyrodite-type solid electrolyte, and an all-solid-state battery including the argyrodite-type solid electrolyte are provided. The method includes a first step of adding precursors represented by the following Formulas 1 and 2 into a polar aprotic solvent, followed by stirring to obtain a reaction solution; a second step of adding P.sub.2S.sub.5 into the stirred reaction solution, followed by further stirring to form a precipitate obtained as a result of the reaction in the reaction solution; and a third step of drying and heat-treating the reaction solution in which the precipitate is formed to obtain a solid electrolyte: [Formula 1] A.sub.2S [Formula 2] AX wherein A represents an alkali metal, and X represents an element of the halogen group.