A solid electrolyte according to the present disclosure is represented by the following compositional formula (1).

Li.sub.7-2x-zLa.sub.3(Zr.sub.2-x-zW.sub.xM.sub.z)O.sub.12  (1)

In the formula (1), x and z satisfy 0.10≤x≤0.60 and 0.00<z≤0.25, and M is at least one type of element selected from the group consisting of Nb, Ta, and Sb.

An electrochemical energy storage device is provided. The device may include a solid-state anode layer. The device may comprise a solid-state electrolyte layer. Further, the device may comprise a solid-state cathode layer. At least two adjacent ones out of the solid-state anode layer, the solid-state electrolyte layer, and the solid-state cathode layer may form a solid-state single-crystal with varying chemical compositions between the related layers. The solid-state electrolyte layer may have an ionic conductivity at room temperature higher than 10.sup.−6 S/cm.

Methods of forming sintered compounds and compounds formed using the methods are disclosed. Exemplary methods include reactive flash sintering to form sintered compounds from two or more starting compounds. Various sintered compounds may be suitable for use as solid electrolytes in solid-state electrochemical cells and batteries.

Herein discussed is a method of using an oxide ion conducting membrane comprising exposing the oxide ion conducting membrane to a reducing environment on both sides of the membrane. In an embodiment, the oxide ion conducting membrane also conducts electrons. In various embodiments, the membrane is impermeable to fluid flow (e.g., having a permeability of less than 1 micro darcy). In an embodiment, the oxide ion conducting membrane comprises lanthanum chromite and a material selected from the group consisting of doped ceria, yttria-stabilized zirconia (YSZ), lanthanum strontium gallate magnesite (LSGM), scandia-stabilized zirconia (SSZ), Sc and Ce doped zirconia, and combinations thereof. In an embodiment, the lanthanum chromite comprises undoped lanthanum chromite, strontium doped lanthanum chromite, iron doped lanthanum chromite, strontium and iron doped lanthanum chromite, lanthanum calcium chromite, or combinations thereof. In an embodiment, the membrane is mixed conducting.

A precursor structure is provided. The precursor structure has the following chemical formula:

[00001]$\left({\mathrm{La}}_2.Math.{\mathrm{Zr}}_{2-x}.Math.M_x.Math.O_7\right).Math.\frac{1}{2}.Math.\left({\mathrm{La}}_{2-y}.Math.M_y^{\prime }.Math.O_3\right),$

wherein M is a trivalent ion or a pentavalent ion, M′ is a bivalent ion, x=0-1, y=0-1.5, and the precursor structure includes a pyrochlore phase. Since the pyrochlore phase may be transformed into the garnet phase through a lithiation process and the phase transition temperature is lower (e.g., 500-1000° C.), the precursor structure may be co-fired with the cathode material (e.g., lithium cobalt oxide (LiCoO.sub.2)) to form a thin lamination structure. That is, the thickness of the solid electrolyte may be effectively reduced, thereby improving the ionic conductivity of the solid electrolyte ion battery.

A process for preparing doped-lithium lanthanum zirconium oxide (doped-LLZO) is described herein. The method involves dry doping of a co-precipitated lanthanum zirconium oxide (LZO) precursor. Dry doping is a process in which a dry powdered dopant is ground and mixed with a pre-prepared co-precipitated LZO precursor and a lithium salt to provide a LLZO precursor composition, which is subsequently calcined to form a doped-LLZO. The process described herein comprises calcining a dry, powdered (e.g., micron, sub-micron or nano-powdered) mixture of a co-precipitated LZO precursor, a dopant salt or oxide, and a lithium salt under an oxygen-containing atmosphere at a temperature in the range of about 500 to about 1100° C., and recovering the doped-LLZO after calcining.

This document describes processes for preparing ceramics, especially lithium-based ceramics. The ceramics produced by this process and their use in electrochemical applications are also described as well as electrode materials, electrodes, electrolyte compositions, and electrochemical cells comprising them.

A solid electrolyte including: an oxide represented by Formula 1, Formula 2, Formula 3, or a combination thereof,

Li.sub.2+4xM1.sub.1−xO.sub.3  Formula 1

wherein, in Formula 1, M1 is hafnium, titanium, zirconium, or a combination thereof, and 0<x<1;

Li.sub.2−y(a−4)M1.sub.1−yM2.sup.a.sub.yO.sub.3  Formula 2

wherein, in Formula 2, M1 is hafnium, titanium, zirconium, or a combination thereof, M2 is at least one element having an oxidation number of a, and wherein a is an integer from 1 to 6, and 0<y<1; or

Li.sub.2−zM1O.sub.3−zX.sub.z  Formula 3

wherein, in Formula 3, M1 is hafnium, titanium, zirconium, or a combination thereof, X is a halogen, a pseudohalogen, or a combination thereof, and 0<z<2.

This disclosure provides systems, methods, and apparatus related to an all-solid-state battery including a solid electrolyte. In one aspect, a device includes a first layer of an ionically conducting oxide, a second layer of the ionically conducting oxide disposed on the first layer, and an anode disposed on the second layer of the ionically conducting oxide. The first layer defines through pores having a tortuosity of about 1. The first layer includes transition metal oxide particles and an ionically conducting solid disposed in the through pores. The transition metal oxide particles are a cathode. The first layer and the ionically conducting solid are an electrolyte. The second layer does not define any through pores. The second layer is a separator.

One or more embodiments of the present invention are to provide a method for producing a composite metal oxide having an excellent crystallinity by a mechanochemical method. One or more embodiments of the present invention relate to a method for producing a garnet-type composite metal oxide containing Li, La, Zr and O. The method includes a step of treating a mixture containing raw material powders and a flux by a mechanochemical method to react the raw material powders, and the raw material powders contain a Li source powder, a La source powder and a Zr source powder. The raw material powders may further contain at least one selected from an Al source powder and a Ga source powder.