A modified garnet-type solid electrolyte, includes: a garnet-type solid electrolyte; a modification layer, such that the modification layer is formed on at least one side of the garnet-type solid electrolyte, and possesses a three-dimensional crosslinking structure comprising at least one strongly acidic lithium salt and at least one weakly acidic lithium salt. A method of forming a modified garnet-type solid electrolyte, includes: exposing a garnet-type solid electrolyte in air to form a pre-passivation layer; mixing solutions of strong acid and weakly acidic salt to form a mixed solution; chemically treating at least one side of the garnet-type solid electrolyte with the mixed solution; and forming a modification layer on the at least one side of the garnet-type solid electrolyte.

A sintered composite ceramic, including: a lithium-garnet major phase; and a grain growth inhibitor minor phase, such that the grain growth inhibitor minor phase has a metal oxide in a range of 0.1 wt. % to 10 wt. % based on the total weight of the sintered composite ceramic.

Described are a solid material which has ionic conductivity for lithium ions, a composite comprising said solid material and a cathode active material, a process for preparing said solid material, a solid structure selected from the group consisting of a cathode, an anode and a separator for an electrochemical cell comprising the solid material, and an electrochemical cell comprising such solid structure.

An electrolyte according to the present disclosure contains a lithium composite metal oxide represented by the following compositional formula.
Li.sub.7-xLa.sub.3(Zr.sub.2-xA.sub.x)O.sub.12-yF.sub.y
In the formula, 0.1≤x≤1.0, 0.0<y≤1.0, and A represents two or more types of Ta, Nb, and Sb.

Disclosed is a solid state electrolyte comprising a compound of Formula 1
Li.sub.7−a*α−(b−4)*β−xM.sup.a.sub.αLa.sub.3Hf.sub.2−βM.sup.b.sub.βO.sub.12−x−δX.sub.x  (1)
wherein M.sup.a is a cationic element having a valence of a+; M.sup.b is a cationic element having a valence of b+; and X is an anion having a valence of −1, wherein, when M.sup.a includes H, 0≤α≤5, otherwise 0≤α≤0.75, and wherein 0≤β≤1.5, 0≤x≤1.5, and (a*α+(b−4)β+x)>0, 0≤δ≤1.

Disclosed are embodiments of making a high Q ceramic material. The method includes providing Ba.sub.3CoTa.sub.2O.sub.9 and incorporating one of Ba.sub.2MgWO.sub.6, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.2MgWO.sub.6, Ba.sub.3LaTa.sub.3O.sub.12, Ba.sub.8LiTa.sub.5WO.sub.24, BaLaLiWO.sub.6, Ba.sub.4Ta.sub.2WO.sub.12, Ba.sub.2La.sub.2MgW.sub.2O.sub.12, BaLaLiWO.sub.6, Sr.sub.3LaTa.sub.3O.sub.12, and SrLaTaO.sub.12 into the Ba.sub.3CoTa.sub.2O.sub.9 to form a solid solution having a high Q value of greater than 12000 at about 10 GHz.

Disclosed are embodiments of making a high Q ceramic material. The method includes providing Ba.sub.3NiTa.sub.2O.sub.9 and incorporating one of Ba.sub.2MgWO.sub.6, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.8LiTa.sub.5WO.sub.24, Ba.sub.2MgWO.sub.6, Ba.sub.3LaTa.sub.3O.sub.12, Ba.sub.8LiTa.sub.5WO.sub.24, BaLaLiWO.sub.6, Ba.sub.4Ta.sub.2WO.sub.12, Ba.sub.2La.sub.2MgW.sub.2O.sub.12, BaLaLiWO.sub.6, Sr.sub.3LaTa.sub.3O.sub.12, and SrLaTaO.sub.12 into the Ba.sub.3NiTa.sub.2O.sub.9 to form a solid solution having a high Q value of greater than 12000 at about 10 GHz.

The present disclosure relates to the technical field of ceramic powder preparation, and discloses a zirconia/titania/cerium oxide doped rare earth tantalum/niobate RETa/NbO.sub.4 ceramic powder and a preparation method thereof. A general chemical formula of the ceramic powder is RE.sub.1-x(Ta/Nb).sub.1-x(Zr/Ce/Ti).sub.2xO.sub.4, 0<x<1, the crystal structure of the ceramic powder is orthorhombic, the lattice space group of the ceramic powder is C222.sub.1, the particle size of the ceramic powder ranges from 10 to 70 μm, and particles of the ceramic powder are spherical. During preparation, the raw materials are ball-milled before a high temperature solid phase reaction, then mixed with a solvent and an organic binder to obtain a slurry C, then centrifuged and atomized to obtain dry pellets, and finally sintered to obtain a zirconia/titanium oxide/cerium oxide doped rare earth tantalum/niobate RETa/NbO.sub.4 ceramic powder, which satisfies the requirements of APS technology for ceramic powders.

Disclosed are embodiments of a barium magnesium tantalate including additional components to increase the Q value of the material. In some embodiments, complex tungsten oxides and/or hexagonal perovskite crystal structures can be added into the barium magnesium tantalate to provide for advantageous properties. In some embodiments, no tin is used in the formation of the material.

According to one embodiment, provided is a composite oxide containing lithium, niobium, and tantalum. A mass ratio of tantalum with respect to niobium is in a range of from 0.01% to 1.0%.