An electrode assembly includes a composite body which includes an active material layer containing an active material constituted by a transition metal oxide, a solid electrolyte layer (solid electrolyte portion) containing a solid electrolyte, and a multiple oxide molded body (multiple oxide portion) containing at least one of a metal multiple oxide represented by the following general formula (1): Ln.sub.2Li.sub.0.5M.sub.0.5O.sub.4 (wherein Ln represents a lanthanoid, and M represents a transition metal) and a derivative thereof, and a current collector which is provided on one face (one of the faces) of the composite body by being bonded to the active material layer, wherein in the composite body, the multiple oxide molded body, the active material layer, and the solid electrolyte layer are formed in contact with each other in this order from the side of the one face of the composite body.

A mixed ionic and electronic conductor represented by Formula 1:
T.sub.xVa.sub.yA.sub.1-x-yM.sub.zO.sub.3-δ,
wherein T includes at least one monovalent cation, A includes at least one of a monovalent cation, a divalent cation, and a trivalent cation, M includes at least one of a trivalent cation, a tetravalent cation, and a pentavalent cation, M is an element other than Ti and Zr, Va is a vacancy, δ is an oxygen vacancy, 0<x, y≤0.25, 0<z<1, and 0≤δ≤1.

A positive electrode active material includes powder of composite particles including a lithium transition metal composite oxide having a lamellar rock-salt structure and a spinel phase. The spinel phase includes an oxide including lithium and at least a first element X1 selected from the group consisting of magnesium, aluminum, titanium, manganese, yttrium, zirconium, molybdenum, and tungsten, and the lithium transition metal composite oxide includes nickel or cobalt and the first element X1.

A cathode configured to use oxygen as a cathode active material includes: a porous film including a metal oxide, where a porosity of the porous film is about 50 volume percent to about 95 volume percent, based on a total volume of the porous film, and an amount of an organic component in the porous film is 0 to about 2 weight percent, based on a total weight of the porous film.

A powder material for an air electrode in a solid oxide fuel cell, the powder material being a powder of a metal composite oxide having a perovskite crystal structure represented by:

A1.sub.1-xA2.sub.xBO.sub.3-δ, where the element A1 is at least one selected from the group consisting of La and Sm, the element A2 is at least one selected from the group consisting of Ca, Sr, and Ba, the element B is at least one selected from the group consisting of Mn, Fe, Co, and Ni, x satisfies 0<x<1, and δ is an oxygen deficiency amount. The powder has a specific surface area of 20 m.sup.2/g or more, satisfies (Crystallite diameter/Specific surface area-based particle diameter)≥0.3, and contains elements M in an amount of 300 ppm or less in terms of atoms, the elements M being other than the elements A1, A2 and B, and oxygen.

Disclosed herein are doped perovskite oxides. The doped perovskite oxides may be used as a cathode material in an electrochemical cell to electrochemically generate ammonia from N.sub.2. The doped perovskite oxides may be combined with nitride compounds, for instance iron nitride, to further increase the efficiency of the ammonia production.

Disclosed herein are doped thermoelectric ceramic oxide compositions comprising a calcium cobaltite ceramic. The doped thermoelectric ceramic oxide compositions can have a formula Ca.sub.3-xM.sup.2.sub.xCo.sub.4O.sub.9M.sup.1.sub.y, where M.sup.1 represents a first metal dopant, M.sup.2 represents a second metal dopant, x is a number having a value of from about 0.00 to about 3.00, and y is a number having a value of from about 0.01 to about 0.50. The doped thermoelectric ceramic oxide compositions have an increased energy conversion efficiency as compared to an undoped or conventional thermoelectric ceramic oxide materials. Also disclosed are methods for making the doped thermoelectric ceramic oxide compositions. Products and devices are disclosed comprising the thermoelectric ceramic oxide compositions, e.g., solid-state conversion devices that can utilize heat to generate electricity. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

This ferrite sintered magnet comprises metallic elements at an atomic ratio represented by formula (1):
Ca.sub.1-w-xR.sub.wSr.sub.xFe.sub.zCo.sub.m  (1) in formula (1), R is at least one element selected from the group consisting of rare-earth elements and Bi, and R comprises at least La, in formula (1), w, x, z and m satisfy formulae (2) to (5):
0.360≤w≤0.420  (2)
0.110≤x≤0.173  (3)
8.51≤z≤9.71  (4)
0.208≤m≤0.269  (5), and in a section parallel to an axis of easy magnetization, when the number of total ferrite grains is N and the number of ferrite grains having a stacking fault is n, 0≤n/N≤0.20 is satisfied.

The present disclosure relates to the field of new materials, and aims at providing a two-dimensional high-entropy metal oxide assembly with high thermal conductivity and a preparation method thereof. The two-dimensional high-entropy metal oxide assembly with the high thermal conductivity has a molecular formula of (Co.sub.0.3La.sub.0.6Er.sub.0.6Y.sub.0.7Mn.sub.0.4Ga.sub.0.4)O.sub.4. The two-dimensional high-entropy metal oxide assembly with the high thermal conductivity is in a short fiber shape with a length-diameter ratio of the short fiber of 5 to 7 and has a cross section of a regular triangle with the side length of the regular triangle of 100 to 300 nm. The present disclosure achieves one-dimensional high thermal conductivity of metal oxide assembly by means of orderly assembling of high-entropy oxide in the direction perpendicular to nanosheets. Meanwhile, the assembly enables uniform distribution of heterogeneous elements in the two-dimensional plane during the preparation process.

The present invention relates to a composite of a cobalt-based perovskite material with a negative thermal expansion material, and a preparation method of the same, and a solid oxide fuel cell (SOFC) comprising the same, and belongs to the technical field of fuel cells. In the present invention, a negative thermal expansion material is introduced into a cobalt-based perovskite oxide to successfully prepare an SOFC cathode material with excellent electrochemical performance and low thermal expansivity. The composite electrode achieves prominent mechanical tolerance in SOFC, which can moderate a volume change during the whole calcination process and enable a smooth transition to a high-temperature stage. The composite electrode has a thermal expansion coefficient (TEC) only of 12.9×10.sup.−6 K.sup.−1, which is perfectly matched with that of an SDC electrolyte. In addition, the composite shows excellent oxygen reduction reaction (ORR) activity, high TEC, and extremely-excellent anti-CO.sub.2 poisoning performance.