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.

Molten lithium-sulfur and lithium-selenium electrochemical cells are disclosed. A solid electrolyte separates a molten lithium metal or molten lithium metal alloy from a molten sulfur or molten selenium. The molten lithium-sulfur and lithium-selenium cells have low over potential, no side reaction, and no dendrite growth. These cells have high Coulombic efficiency and energy efficiency and thus provide new chemistries to construct high-energy, high-power, long-lifetime, low-cost and safe energy storage systems.

The solid electrolyte according to an embodiment of the present disclosure is represented by the following formula (1):

Li.sub.7−yLa.sub.3 (Zr.sub.2−x−yGe.sub.xM.sub.y) O.sub.12   (1)

wherein 0.00<x≤0.40, 0.00<y≤1.50, M is Sb or is Sb and an element of at least one of Nb and Ta.

A lead-free KNN-based piezoelectric material represented by the composition formula (K.sub.aNa.sub.bLi.sub.c)(Nb.sub.dTa.sub.eSb.sub.f)O.sub.g, where 0.4≤a≤0.5, 0.5≤b≤0.6, 0.01≤c≤0.1, 0.5≤d≤1.0, 0.05≤e≤0.15, 0.01≤f≤0.09, 1≤g≤3. In one embodiment, the lead-free KNN-based piezoelectric material has a d.sub.33>300 pm/V and a T.sub.curie>250° C. In one embodiment, the d.sub.33 and T.sub.curie of the lead-free textured KNN-based piezoelectric material can be adjusted by creating phase boundaries of (i) orthorhombic to tetragonal (O-T), (ii) rhombohedral to orthorhombic (R-O), and (iii) orthorhombic to tetragonal (O-T). In one embodiment, the lead-free KNN-based piezoelectric material is textured with NaNbO.sub.3 or Ba.sub.2NaNb.sub.5O.sub.15 seeds which are platelet or acicular shaped. In one embodiment, the amount, orientation, or particle size distribution of the NaNbO.sub.3 or Ba.sub.2NaNb.sub.5O.sub.15 texturing seeds in the lead-free textured KNN-based piezoelectric material can be altered.

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.

Solid-state lithium ion electrolytes of lithium potassium tantalate based compounds are provided which contain an anionic framework capable of conducting lithium ions. An activation energy of the lithium metal silicate composites is from 0.12 to 0.45 eV and conductivities are from 10.sup.−3 to 40 mS/cm at 300K. Compounds of specific formulae are provided and methods to alter the materials with inclusion of aliovalent ions shown. Lithium batteries containing the composite lithium ion electrolytes are also provided. Electrodes containing the lithium potassium tantalate based materials and batteries with such electrodes are also provided.

To provide a lithium ion conductive crystal body having a high density and a large length and an all-solid state lithium ion secondary battery containing the lithium ion conductive crystal body. A Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body, which is one example of the lithium ion conductive crystal body, has a relative density of 99% or more, belongs to a cubic system, has a garnet-related type structure, and has a length of 2 cm or more. The Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body is grown by a melting method employing a Li.sub.5La.sub.3Ta.sub.2O.sub.12 polycrystal body as a raw material. With the growing method, a Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body having a relative density of 100% can also be obtained. In addition, the all-solid state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, in which the solid electrolyte contains the lithium ion conductive crystal body.

A capacitive element and a dielectric thin film having a small dielectric loss and a large relative permittivity, particularly at low frequencies. [Solution] This dielectric thin film includes an A-B—O—N oxynitride. When the A-B—O—N oxynitride is represented by the compositional formula A.sub.aB.sub.bO.sub.oN.sub.n, (o+n)/a<3.00 is satisfied.

Fabricating a layer including lithium lanthanum zirconate (Li.sub.7La.sub.3Zr.sub.2O.sub.12) layer includes forming a slurry including lanthanum zirconate (La.sub.2Zr.sub.2O.sub.7) nanocrystals, a lithium precursor, and a lanthanum precursor in stoichiometric amounts to yield a dispersion including lithium, lanthanum, and zirconium. In some cases, the dispersion includes lithium, lanthanum, and zirconium in a molar ratio of 7:3:2. In certain cases, the slurry includes excess lithium. The slurry is dispensed onto a substrate and dried. The dried slurry is calcined to yield the layer including lithium lanthanum zirconate.

The present disclosure provides solid electrolyte materials having high lithium ion conductivity. A solid electrolyte material according to the present disclosure consists essentially of Li, M, O, and X. M is at least one element selected from the group consisting of Nb and Ta. X is at least one element selected from the group consisting of Cl, Br, and I.