The instant disclosure sets forth multiphase lithium-stuffed garnet electrolytes having secondary phase inclusions, wherein these secondary phase inclusions are material(s) which is/are not a cubic phase lithium-stuffed garnet but which is/are entrapped or enclosed within a lithium-stuffed garnet. When the secondary phase inclusions described herein are included in a lithium-stuffed garnet at 30-0.1 volume %, the inclusions stabilize the multiphase matrix and allow for improved sintering of the lithium-stuffed garnet. The electrolytes described herein, which include lithium-stuffed garnet with secondary phase inclusions, have an improved sinterability and density compared to phase pure cubic lithium-stuffed garnet having the formula Li.sub.7La.sub.3Zr.sub.2O.sub.12.

The purpose of the present invention is to provide an active material for a secondary battery electrode, the active material having excellent rate characteristics and cycle resistance. The present invention is an active material for a secondary battery electrode, the active material having an olivine-type crystal structure, while having a carbon layer on the surface, wherein the ratio of the average thickness of the carbon layer which is present on a plane that is perpendicular to the crystal b-axis to the average thickness of the carbon layer which is present on a plane that is not perpendicular to the b-axis is from 0.30 to 0.80.

A negative electrode active material includes a carbon material, where the carbon material has a specific degree of graphitization and aspect ratio distribution. A degree of graphitization Gr of the carbon material measured by an X-ray diffraction analysis method is 0.82 to 0.92, and based on a total quantity of particles of the carbon material, a proportion of particles with an aspect ratio greater than 3.3 in the carbon material is less than 10%. The negative electrode active material helps to improve cycle performance of the electrochemical apparatus. FIG. 1.

Solid-state lithium ion electrolytes of lithium silicate based composites are provided which contain an anionic framework capable of conducting lithium ions. An activation energy for lithium ion migration in the solid state lithium ion electrolytes is 0.5 eV or less and room temperature conductivities are greater than 10.sup.0.5 S/cm. Composites of specific formulae are provided and methods to alter the composite materials with inclusion of aliovalent ions shown. Lithium batteries containing the composite lithium ion electrolytes are also provided.

The present exemplary embodiments relate to a positive electrode active material and a lithium secondary battery including the same. The positive active material for a lithium secondary battery according to an exemplary embodiment includes lithium metal oxide particles including lithium, nickel, cobalt, manganese and doping elements, and includes a first domain and a second domain inside the lithium metal oxide particles.

There is provided a sulfide solid electrolyte containing elemental lithium (Li), elemental phosphorus (P), elemental sulfur (S), and an elemental halogen (X). The mole ratio of the elemental lithium (Li) to the elemental phosphorus (P), Li/P, satisfies 3.7<Li/P<5.4. The mole ratio of the elemental sulfur (S) to the elemental phosphorus (P), S/P, satisfies 3.9<S/P<4.1. The mole ratio of the elemental halogen (X) to the elemental phosphorus (P), X/P, satisfies 0.7<X/P<2.4. The sulfide solid electrolyte includes a crystalline phase having an argyrodite-type crystal structure.

Provided are enhanced MXene materials made from MAX-phase precursors that comprise an excess of metal A. The resultant enhanced MXenes exhibit improved stability over periods of days and months, particularly when stored in aqueous media.

A positive-electrode active material contains a lithium composite oxide containing at least one selected from the group consisting of F, Cl, N, and S. The crystal structure of the lithium composite oxide belongs to a space group C2/m. An XRD pattern of the lithium composite oxide comprises a first peak within the first range of 44 degrees to 46 degrees of a diffraction angle 2θ and a second peak within the second range of 18 degrees to 20 degrees of the diffraction angle 2θ. The ratio of the second integrated intensity of the second peak to the first integrated intensity of the first peak is within a range of 0.05 to 0.90.

A solid electrolyte material contains Li, M, and X. M contains Y, and X is at least one selected from the group consisting of Cl, Br, and I. A first converted pattern, which is obtained by converting the X-ray diffraction pattern of the solid electrolyte material to change its horizontal axis from the diffraction angle to q, includes its base peak within the range in which q is 2.109 Å.sup.−1 or more and 2.315 Å.sup.−1 or less. A second converted pattern, which is obtained by converting the X-ray diffraction pattern to change its horizontal axis from the diffraction angle to q/q.sub.0, where q.sub.0 is the q corresponding to the base peak in the first converted pattern, includes a peak within each of the range in which q/q.sub.0 is 1.28 or more and 1.30 or less and the range in which q/q.sub.0 is 1.51 or more and 1.54 or less.

A plate-shaped sample with a cross-section perpendicular to a radial direction of a polycrystalline silicon rod as a principal surface is sampled from a region from a center (r=0) of the polycrystalline silicon rod to R/3. Then, the sample is disposed at a position at which a Bragg reflection from a (111) Miller index plane is detected. In-plane rotation with a rotational angle φ on the sample is performed with a center of the sample as a rotational center such that an X-ray irradiation region defined by a slit performs φ-scanning on the principal surface of the sample to obtain a diffraction chart indicating dependency of a Bragg reflection intensity from the (111) Miller index plane on a rotational angle of the sample. A ratio (S.sub.p/S.sub.t) between an area S.sub.p of a peak part appearing in the diffraction chart and a total area S.sub.t of the diffraction chart is calculated.