The present disclosure provides a solid electrolyte material having high lithium ion conductivity. The solid electrolyte material according to the present disclosure has a crystal structure including a structure framework and an ion-conductive species, wherein the structure framework has a one-dimensional chain in which a plurality of polyhedrons are linearly connected to each other while sharing a corner, and each of the plurality of polyhedrons contains at least one type of cation and at least one type of anion.

The tantalum chloride according to the present invention contains TaCl.sub.5, and has a total content of tantalum subchlorides of 1% by mass or less.

The tantalum chloride according to the present invention contains TaCl.sub.5, and has a total content of tantalum subchlorides of 1% by mass or less.

A solid electrolyte composition of the present disclosure includes: a solid electrolyte including Li, Ml, O, and X1, a halide including M2 and X2; and an organic solvent. The M1 is at least one selected from the group consisting of Nb and Ta. The M2 is at least one selected from the group consisting of Nb and Ta. The X1 is at least one selected from the group consisting of F, Cl, Br, and I. The X2 is at least one selected from the group consisting of F, Cl, Br, and I.

A solid electrolyte composition of the present disclosure includes: a solid electrolyte including Li, Ml, O, and X1, a halide including M2 and X2; and an organic solvent. The M1 is at least one selected from the group consisting of Nb and Ta. The M2 is at least one selected from the group consisting of Nb and Ta. The X1 is at least one selected from the group consisting of F, Cl, Br, and I. The X2 is at least one selected from the group consisting of F, Cl, Br, and I.

A solid electrolyte material comprises a crystal structure including a structure framework and an ion-conductive species. The structure framework has a one-dimensional chain. In the one-dimensional chain, a plurality of polyhedrons are linearly connected to each other while sharing a corner, and each of the plurality of polyhedrons contains at least one type of cation and at least one type of anion.

A solid electrolyte material of the present disclosure comprises Li, M, O, and X, wherein M is at least one selected from the group consisting of Nb and Ta, and X is at least one selected from the group consisting of F, Cl, Br, and I. The solid electrolyte material contains columnar crystals. The average of aspect ratios (L/W) of the length (L) and the width (W) of the columnar crystals is 5 or more, and the average length is 20 m or less. A battery of the present disclosure includes a positive electrode, a negative electrode, and an electrolyte layer disposed 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 contains the solid electrolyte material according to the present disclosure.

A solid electrolyte material of the present disclosure comprises Li, M, O, and X, wherein M is at least one selected from the group consisting of Nb and Ta, and X is at least one selected from the group consisting of F, Cl, Br, and I. The solid electrolyte material contains columnar crystals. The average of aspect ratios (L/W) of the length (L) and the width (W) of the columnar crystals is 5 or more, and the average length is 20 m or less. A battery of the present disclosure includes a positive electrode, a negative electrode, and an electrolyte layer disposed 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 contains the solid electrolyte material according to the present disclosure.