A positive-electrode material according to the present disclosure includes a positive-electrode active material and a coating layer covering the positive-electrode active material, wherein the coating layer contains niobium and carbon, the positive-electrode active material and the coating layer constitute a coated active material, and the ratio Nb/C of the niobium content to the carbon content in a surface layer portion of the coated active material is 0.11 or more based on the atomic ratio.

A positive electrode material contains a positive electrode active material and a first solid electrolyte material. The first solid electrolyte material contains Li, M, and X; M at least contains yttrium; and X is at least one selected from the group consisting of Cl, Br, and I.

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 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.

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.

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 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 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 electrolyte material contains Li; Y; at least one selected from the group consisting of Mg, Ca, Sr, Ba, Zn, Zr, 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 using Cu—Kα radiation as an X-ray source includes peaks in a range of diffraction angles 2θ of 30° or more and 33° or less, in a range of diffraction angles 2θ of 39° or more and 43° or less, and in a range of diffraction angles 2θ of 47° or more and 51° or less.

A solid electrolyte material contains Li; Y; at least one selected from the group consisting of Mg, Ca, Sr, Ba, Zn, Zr, 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 using Cu—Kα radiation as an X-ray source includes peaks in a range of diffraction angles 2θ of 30° or more and 33° or less, in a range of diffraction angles 2θ of 39° or more and 43° or less, and in a range of diffraction angles 2θ of 47° or more and 51° or less.