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.

Disclosed herein are embodiments of n and p-type components with high temperature refractory material having a perovskite crystal structure. The material may be doped to generate, for example, p-type and n-type sensor legs. In some embodiments, expensive materials may be avoided. Further, the disclosed materials can avoid high temperature reaction between n-type components and p-type components.

A ceramic member includes a perovskite compound including La, Ca, Mn, and Ti as main components, wherein the amount of Ti is about 5 parts by mole or more and about 20 parts by mole or less, the amount of Ca is about 10 parts by mole or more and about 27 parts by mole or less, and the total amount of La and Ca is about 85 parts by mole or more and about 97 parts by mole or less based on the total amount of Mn and Ti of 100 parts by mole.

A ceramic member comprising a compound oxide of La, E and Mn, wherein AE is (i) Ca, or (ii) contains Ca and at least one of Sr and Ba with a total amount of Sr and Ba to a total of Ca, Sr and Ba of not more than 5 mol %, and a crystal system in a surface of the ceramic member is a monoclinic system.

Thermochemical storage materials having the general formula A.sub.xA.sub.1-xB.sub.yB.sub.1-yO.sub.3-, where A=La, Sr, K, Ca, Ba, Y and B=Mn, Fe, Co, Ti, Ni, Cu, Zr, Al, Y, Cr, V, Nb, Mo, are disclosed. These materials have improved thermal storage energy density and reaction kinetics compared to previous materials. Concentrating solar power thermochemical systems and methods capable of storing heat energy by using these thermochemical storage materials are also disclosed.

A ceramic member comprising a compound oxide of La, E and Mn, wherein AE is (i) Ca, or (ii) contains Ca and at least one of Sr and Ba with a total amount of Sr and Ba to a total of Ca, Sr and Ba of not more than 5 mol %, and a crystal system in a surface of the ceramic member is a monoclinic system.

A method for the rapid and controlled synthesis of mixed metal oxide nanoparticles using relatively low temperature plasma oxidation of liquid droplets of predetermined mixed metal precursors is disclosed. The resulting nanoparticles reflect the metal precursor stoichiometries and the mixed metal oxide's metastable phase can be controlled. The synthesis of mixed transition metal oxide comprising binary metal oxides, ternary mixed metal oxides, quaternary mixed metal oxides and pentanary mixed metal oxides are demonstrated herein.

A composition consisting essentially of a perovskite crystalline structure, the composition comprising: ions of a first metal M.sup.1 which occupies an A-site of the perovskite crystalline structure; ions of a second metal M.sup.2 which occupies a B-site of the perovskite crystalline structure, M.sup.2 having two oxidation states capable of forming a redox couple suitable for reversibly catalyzing an oxygen reduction reaction (ORR) and an oxygen evolution reaction (OER); ions of a third metal M.sup.3 at least a portion of which substitutes for M.sup.1 in the A-site of the perovskite crystalline structure, and at least a portion of which optionally also substitutes for M.sup.2 in the B-site of the perovskite crystalline structure, at least some of the atoms M.sup.3 having a different oxidation state to the atoms M.sup.1; and atoms of an element X, which is a chalcogen; wherein the metal ions M.sup.1, M.sup.2 and M.sup.3 are present in the atomic ratios (a) or (b): (a) 25 to 49.9 atomic % M.sup.1, 30 to 60 atomic % M.sup.2, and 5 to 45 atomic % M.sup.3; (b) 10 to 30 atomic % M.sup.1, 50.1 to 60 atomic % M.sup.2, and 25 to 45 atomic % M.sup.3; each expressed as a percentage of the total metal ions in the composition excluding oxygen; wherein the presence of the M.sup.3 ions causes a change in the oxidation state of some of the M.sup.2 ions in the structure, thereby creating the redox couple suitable for reversibly catalyzing the ORR and OER.

A mixed ionic and electronic conductor represented by Formula 1:

T.sub.xVa.sub.yA.sub.1-x-yM.sub.zO.sub.3-,

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, is an oxygen vacancy, 0<x, y0.25, 0<z<1, and 01.

A perovskite material represented by Formula 1:

Li.sub.xA.sub.yM.sub.zO.sub.3-Formula 1 wherein in Formula 1, 0<x1, 0<y1, 0<x+y<1, 0<z1.5, 01, A is H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, or a combination thereof, and M is Ni, Pd, Pb, Fe, Ir, Co, Rh, Mn, Cr, Ru, Re, Sn, V, Ge, W, Zr, Mo, Hf, U, Nb, Th, Ta, Bi, Li, H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Mg, Al, Si, Sc, Zn, Ga, Ag, Cd, In, Sb, Pt, Au, or a combination thereof.