A technique disclosed herein provides a positive electrode active material having a granular shape and used for a positive electrode of a secondary battery. The positive electrode active material includes, as an essential component, a lithium transition metal composite oxide containing at least manganese as a transition metal element and having a layered rock salt structure. A concentration difference between an average Mn concentration and a local maximum Mn concentration is equal to or less than 4 atm %, the average Mn concentration being measured based on ICP emission spectroscopic analysis of the positive electrode active material, and the local maximum Mn concentration being measured based on energy dispersive X-ray analysis with a transmission electron microscope.

Modified copper chromite spinel pigments exhibit lower coefficients of thermal expansion than unmodified structures. Three methods exist to modify the pigments: (1) the incorporation of secondary modifiers into the pigment core composition, (2) control of the pigment firing profile, including both the temperature and the soak time, and (3) control of the pigment core composition.

Alumina is generally used as an inorganic filler, while spinel, which is known to be lower in thermal conductivity than alumina, is used in applications such as gems, fluorescence emitters, catalyst carriers, adsorbents, photocatalysts and heat-resistant insulating materials, but not expected to be used as a thermally conductive inorganic filler. Thus, an object of the invention is to provide spinel particles having excellent thermal conductive properties. The invention relates to a spinel particle including magnesium, aluminum and oxygen atoms and molybdenum and having a [111] plane crystallite diameter of 220 nm or more.

A lithium-rich oxide positive electrode material. At least one unit lattice parameter (a, b, c) of the material decreases as the temperature increases at a temperature between 50 to 350 degrees. After treatment for 0.5 to 10 hours under the condition of 150 to 350° C., the degree of ordering of the material structure is increased, and the material has a higher discharge specific capacity and a higher discharge voltage when applied to a positive electrode of a lithium ion battery.

Provided are an electrode active material for a secondary battery containing a first electrode active material and a second electrode active material, in which the first electrode active material expands during charging and contracts during discharging, the second electrode active material contracts during charging and expands during discharging, some of particles constituting the first electrode active material and some of particles constituting the second electrode active material are in contact with each other, and an interface in which the particles constituting the first active material and the particles constituting the second active material are in contact with each other forms a solid solution to form a crystal portion, a solid electrolyte composition, an electrode sheet for an all-solid state secondary battery, and an all-solid state secondary battery for which the electrode active material for a secondary battery is used, and methods for manufacturing the electrode active material for a secondary battery, an electrode sheet for an all-solid state secondary battery, and an all-solid state secondary battery.

Methods for preparation of surfactant-free ultra-small spinel ternary metal oxide nanoparticles are provided. A method comprises dissolving first and second metal salts in deionized water in a specific mole ratio to form a solution comprising two different metal ions, applying a coprecipitation method and adding an alkaline solution to the solution to form a colloidal suspension, wherein a colloid of the colloidal suspension is a metal hydroxide, adjusting the amount and the addition rate of the alkaline solution to form a specific structure of metal hydroxide precipitate; washing and drying the metal hydroxide to form a structured metal hydroxide powder, and applying a calcination method to the structured metal hydroxide powder to form a surfactant-free spinel-type (AB.sub.2O.sub.4) ternary metal oxide, wherein A and B each respectively comprise a metal element.

A mixed conductor represented by Formula 1:
A.sub.4+xM.sub.5-yM′.sub.yO.sub.12-δ,  Formula 1
wherein, in Formula 1, A is a monovalent cation, M is at least one of a divalent cation, a trivalent cation, or a tetravalent cation, M′ is at least one of a monovalent cation, a divalent cation, a trivalent cation, a tetravalent cation, a pentavalent cation, or a hexavalent cation, M and M′ are different from each other, and 0.3≤x<3, 0.01<y<2, and 0≤δ≤1 are satisfied.

A cathode active material includes a composition expressed as:

Li.sub.1+β(Ni.sub.xMn.sub.yCo.sub.z).sup.M1.sub.α(Ni.sub.x′Mn.sub.y′Co.sub.z′).sup.M2.sub.1−αO.sub.2; or

Na.sub.1+β(Ni.sub.xMn.sub.yCo.sub.z).sup.M1.sub.α(Ni.sub.x′Mn.sub.y′Co.sub.z′).sup.M2.sub.1−αO.sub.2;

where: M1 represents a core composition comprising of Ni, Mn, and/or Co or a combination of at two of thereof; M2 represents a surface composition having at least 50% Co, and, optionally Ni and/or Mn; the structure of M2 may be a composite structure and includes a rock-salt or disordered rock-salt phase; 0.5≤α<1, 0≤x≤1, 0≤y≤0.5, 0≤z≤1, 0≤x′≤0.5, 0≤y′≤0.5, 0.5≤z′≤1, and −0.1≤β≤0.1; the sum of x, y and z is 0.9-1.1, and the sum of x′, y′ and z′ is 0.9-1.1.

A ceramic material, a varistor and methods for forming a ceramic material and a varistor are disclosed. In an embodiment, a ceramic material includes ZnO as a main component and additives selected from the group consisting of an Al.sup.3+-containing solution, a Ba.sup.2+-containing solution, and at least one compound containing a metal element, wherein the metal element is selected from the group consisting of Bi, Sb, Co, Mn, Ni, Y, and Cr.

A lithium-manganese composite oxide containing a lithium-iron-manganese composite oxide represented by the composition formula. Li.sub.1+x−w(Fe.sub.yNi.sub.zMn.sub.1−y−z).sub.1−xO.sub.2−δ, where 0<x<1/3, 0≤w<0.8, 0<y<1, 0<z<0.5, y+z<1, and 0≤δ<0.5, in which at least in a state of charge of a lithium ion battery using the lithium-manganese composite oxide as a positive-electrode active material, at least some of iron atoms are pentavalent.