The present invention concerns new lithium rare earth halides that may be used as solid electrolytes or in electrochemical devices. The invention also refers to wet and dry processes for the synthesis of such lithium rare earth halides and lithium rare earth halides susceptible to be obtained by these processes.

Provided are a sodium ion-conductive crystal-containing solid electrolyte sheet capable of giving excellent battery characteristics even when reduced in thickness, and an all-solid-state battery using the same. The solid electrolyte sheet contains at least one type of sodium ion-conductive crystal selected from β″-alumina and NASICON crystal and has a thickness of 500 μm or less and a flatness of 200 μm or less.

An object of the present invention is to provide a scintillator having a high radiation stopping power, and having a shorter fluorescence decay time compared to conventional scintillators. The above object is achieved by setting the composition of a scintillator to a composition represented by General Formula (1).

Q.sub.xM.sub.yO.sub.3z  (1)

(wherein in General Formula (1), Q includes at least two or more divalent metallic elements; M includes at least Hf; and x, y, and z independently satisfy 0.5≤x≤1.5, 0.5≤y≤1.5, and 0.7≤z≤1.5, respectively).

The present invention relates to a mixed oxide of aluminium, of zirconium, of cerium, of lanthanum and optionally of at least one rare-earth metal other than cerium and lanthanum that makes it possible to prepare a catalyst that retains, after severe ageing, a good thermal stability and a good catalytic activity. The invention also relates to the process for preparing this mixed oxide and also to a process for treating exhaust gases from internal combustion engines using a catalyst prepared from this mixed oxide.

A solid electrolyte material contains Li, Y, at least one selected from the group consisting of Mg, Ca, Sr, Ba, Zn, Sc, La, Sm, Bi, Zr, Hf, Nb, and Ta, and at least one selected from the group consisting of Cl, Br, and I. An X-ray diffraction pattern of the solid electrolyte material obtained by using Cu-Kα radiation as the X-ray source includes peaks within the range in which the diffraction angle 2θ is 25° or more and 35° or less, and also includes at least one peak within the range in which the diffraction angle 2θ is 43° or more and 51° or less.

A solid ion conductor compound includes a compound represented by Formula 1:
Li.sub.6−wHf.sub.2−xM.sub.xO.sub.7−yZ.sub.y  Formula 1
where, in Formula 1, M is an element having an oxidation number of a and a is 5, 6, or a combination thereof, Z is an element having an oxidation number of −1, and 0<x<2, 0≤y≤2, and 0<w<6 and w=[(a−4)×x]+y.

A solid electrolyte includes an ion conductor represented by at least one of Formulae 1 to 3,
Li.sub.1+3xM1.sub.1−xO.sub.2  Formula 1
wherein, in Formula 1, M1 is a trivalent element, and 0<x<1,
L.sub.1−yM2O.sub.2−yX.sub.y  Formula 2
wherein, in Formula 2, M2 is a trivalent element, X is at least one of a halogen atom or a pseudohalogen, and 0<y<1,
Li.sub.1−z(a−3)M3.sub.1−zD.sub.zO.sub.2  Formula 3
wherein, in Formula 3, M3 is a trivalent element, D is at least one of a monovalent element to a hexavalent element, and 0<z<1.

A compound of Formula 1
Li.sub.1+(4−a)αHf.sub.2−αM.sup.a.sub.α(PO.sub.4−δ).sub.3  (1)
is disclosed, wherein M is at least one cationic element having a valence of a, wherein 0<α≤⅔, 1≤a≤4, and 0≤δ≤0.1. Also described are an electrolyte composition, a separator, a protected positive electrode, a protected negative electrode, and a lithium battery, each including the compound of Formula 1.

A lithium battery includes: a positive electrode having a positive active material; a negative electrode including lithium metal; and a solid electrolyte disposed therebetween. The solid electrolyte contains at least one oxide represented by Li.sub.4±xM.sub.1-x′M′.sub.x′O.sub.4 (Formula 1), Li.sub.4-yM″O.sub.4-yA′.sub.y (Formula 2), or Li.sub.4+4zM′″.sub.1-zO.sub.4 (Formula 3), wherein and 0≤x23 1 and 0≤x′≤1, M is a Group 4 element, and M′ is an element of Group 2, 3, 5, 12, or 13, a vacancy, or a combination thereof, with the proviso that when M is Zr, then x≠0, x′≠0 and M′ is Be, Ca, Sr, Ba, Ra, Cd, Hg, Cn, Ga, In, TI, an element of Group 3 or 5, or a combination thereof; 0≤y≤1, M″ is a Group 4 element, and A′ includes at least one halogen, with the proviso that when M″ is Zr, then y≠0; and 0<z<1, and M′″ is a Group 4 element.

Disclosed is a solid state electrolyte comprising a compound of Formula 1

Li.sub.7-.sub.a.sub.*α-(b−4)*β−xM.sup.a.sub.αLa.sub.3Hf.sub.2−βM.sup.b.sub.βO.sub.12−x−δX.sub.x   (1)

wherein

M.sup.a is a cationic element having a valence of a+;

M.sup.b is a cationic element having a valence of b+; and

X is an anion having a valence of −1,

wherein, when M.sup.a includes H, 0≤α≤5, otherwise 0≤α≤0.75, and wherein 0≤β≤1.5, 0≤x≤1.5, and (a*α+(b−4)β+x)>0, 0≤δ≤1.