A solid electrolyte material of the present disclosure includes Li, Zr, and F. A ratio of an amount of substance of Li to an amount of substance of Zr is less than 3.5. In an X-ray diffraction pattern obtained by an X-ray diffraction measurement of the solid electrolyte material using a Cu—Kα ray, a ratio of a value of a full width at half maximum of a peak having a highest intensity within a range of a diffraction angle 2θ from 27.5° to 29.5° to a value of a full width at half maximum of a peak corresponding to a (111) plane of Si in an X-ray diffraction pattern of Si measured under a same condition as in the X-ray diffraction measurement is more than 1.06.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

Materials containing picocrystalline quantum dots that form artificial atoms are disclosed. The picocrystalline quantum dots (in the form of born icosahedra with a nearly-symmetrical nuclear configuration) can replace corner silicon atoms in a structure that demonstrates both short range and long-range order as determined by x-ray diffraction of actual samples. A novel class of boron-rich compositions that self-assemble from boron, silicon, hydrogen and, optionally, oxygen is also disclosed. The preferred stoichiometric range for the compositions is (B.sub.12H.sub.w).sub.xSi.sub.yO.sub.z with 3≤w≤5, 2≤x≤4, 2≤y≤5 and 0≤z≤3. By varying oxygen content and the presence or absence of a significant impurity such as gold, unique electrical devices can be constructed that improve upon and are compatible with current semiconductor technology.

Materials containing picocrystalline quantum dots that form artificial atoms are disclosed. The picocrystalline quantum dots (in the form of born icosahedra with a nearly-symmetrical nuclear configuration) can replace corner silicon atoms in a structure that demonstrates both short range and long-range order as determined by x-ray diffraction of actual samples. A novel class of boron-rich compositions that self-assemble from boron, silicon, hydrogen and, optionally, oxygen is also disclosed. The preferred stoichiometric range for the compositions is (B.sub.12H.sub.w).sub.xSi.sub.yO.sub.z with 3≤w≤5, 2≤x≤4, 2≤y≤5 and 0≤z≤3. By varying oxygen content and the presence or absence of a significant impurity such as gold, unique electrical devices can be constructed that improve upon and are compatible with current semiconductor technology.

A solid electrolyte material is represented by the following compositional formula (1):
Li.sub.3-3δ-2aY.sub.1+δ-aM.sub.aCl.sub.6-x-yBr.sub.xI.sub.y where, M is at least one selected from the group consisting of Ta and Nb; and −1<δ<1, 0<a<1.2, 0<(3−3δ−2a), 0<(1+δ−a), 0≤x≤6, 0≤y≤6, and (x+y)≤6 are satisfied.

A solid electrolyte material of the present disclosure includes Li, Zr, and F. A ratio of an amount of substance of Li to an amount of substance of Zr is 3.5 or more. In an X-ray diffraction pattern obtained by an X-ray diffraction measurement of the solid electrolyte material using a Cu-Kα ray, a ratio of a value of a full width at half maximum of a peak having a highest intensity within a range of a diffraction angle 2θ from 42.5° to 44.7° to a value of a full width at half maximum of a peak corresponding to a (111) plane of Si in an X-ray diffraction pattern of Si measured under a same condition as in the X-ray diffraction measurement is more than 1.19.

A solid electrolyte material of the present disclosure includes Li, Zr, Al, and F. A ratio of an amount of substance of F to a total of amounts of substance of anions constituting the solid electrolyte material of the present disclosure may be, for example, 0.50 or more and 1.0 or less. A battery of the present disclosure includes a positive electrode, a negative electrode, and an electrolyte layer provided between the positive electrode and the negative electrode. At least one selected from the group consisting of the positive electrode, the negative electrode, and the electrolyte layer includes the above solid electrolyte material of the present disclosure.

Provided is a battery comprising a cathode, an anode, and an electrolyte layer. The electrolyte layer includes a first electrolyte layer and a second electrolyte layer. The first electrolyte layer includes a first solid electrolyte material. The second electrolyte layer includes a second solid electrolyte material which is a material different from the first solid electrolyte material. The first solid electrolyte material includes lithium, at least one kind selected from the group consisting of metalloid elements and metal elements other than lithium, and at least one kind selected from the group consisting of chlorine, bromine, and iodine. The first solid electrolyte material does not include sulfur.

A solid electrolyte: (compound A) a compound that has a crystal phase having an argyrodite-type crystal structure and that is represented by Li.sub.aPS.sub.bX.sub.c, where X is at least one elemental halogen, a represents a number of 3.0 or more and 6.0 or less, b represents a number of 3.5 or more and 4.8 or less, and c represents a number of 0.1 or more and 3.0 or less; and (compound B) a compound that is represented by LiX, where X is as defined above. The compound B has a crystallite size of 25 nm or more. The solid electrolyte preferably has a BET specific surface area of 14.0 m.sup.2/g or less.

A solid electrolyte which contains a garnet-type composite metal oxide phase (L) and shows an excellent lithium ion conductivity is provided. The solid electrolyte contains a garnet-type composite metal oxide phase (L) and a phase (D) different from the phase (L). The phase (L) contains Li, La, Zr, O, and Ga, and an Li site in the phase (L) is substituted with the Ga. A lattice constant of the solid electrolyte is not smaller than 12.96 Å. The phase (D) contains at least one of LiF, BaZrO.sub.3, YF.sub.3, SrF.sub.2, and ScF.sub.3.