The present invention relates to a nitrogen-doped sulfide-based solid electrolyte for all-solid batteries. The a nitrogen-doped sulfide-based solid electrolyte for all-solid batteries includes a compound with an argyrodite-type crystal structure represented by the following Formula 1:
Li.sub.aPS.sub.bN.sub.cX.sub.d  [Formula 1] wherein 6≤a≤7, 3≤b≤6, 0≤c≤1, 0≤d≤2, and each X is the same or different halogen atom selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I).

A solid electrolyte material contains Li, M, and X. M contains Y, and X is at least one selected from the group consisting of Cl, Br, and I. A first converted pattern, which is obtained by converting the X-ray diffraction pattern of the solid electrolyte material to change its horizontal axis from the diffraction angle to q, includes its base peak within the range in which q is 2.109 Å.sup.−1 or more and 2.315 Å.sup.−1 or less. A second converted pattern, which is obtained by converting the X-ray diffraction pattern to change its horizontal axis from the diffraction angle to q/q.sub.0, where q.sub.0 is the q corresponding to the base peak in the first converted pattern, includes a peak within each of the range in which q/q.sub.0 is 1.28 or more and 1.30 or less and the range in which q/q.sub.0 is 1.51 or more and 1.54 or less.

A secondary battery provides a means for inhibiting the growth of dendrite in a solid electrolyte layer while suppressing the decrease in ion conductivity in the solid electrolyte layer.

In the secondary battery, which includes a power-generating element formed by laminating a positive electrode which contains a positive electrode active material, a solid electrolyte layer which contains a solid electrolyte, and a negative electrode which contains a negative electrode active material, a binder having a Young’s modulus of 200 [MPa] or lower is further contained in the solid electrolyte layer.

A negative active material for an all solid-state includes an aggregated material of amorphous carbon having pores therein in which primary particles are aggregated, and metal nanoparticles filling in the pores.

One aspect of the present invention is a solid electrolyte containing lithium, phosphorus, sulfur, halogen, and tin as constituent elements and having a crystal structure.

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 lithium and carbon, the positive-electrode active material and the coating layer constitute a coated active material, and the ratio C/Li of the carbon content to the lithium content in a surface layer portion of the coated active material is 3.27 or more based on the atomic ratio.

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 oxygen and lithium, the positive-electrode active material and the coating layer constitute a coated active material, and the ratio Li/O of the lithium content to the oxygen content in a surface layer portion of the coated active material is 0.26 or less based on the atomic ratio.

The production method of the present disclosure includes: heat-treating a material mixture containing LiA, YB.sub.3, GdC.sub.3, and CaD.sub.2 in an inert gas atmosphere. A, B, C, and D are each independently at least one selected from the group consisting of F, Cl, Br, and I. In the heat-treating, the material mixture is heat-treated at higher than or equal to 200° C. and lower than or equal to 700° C.

A solid electrolyte material according to the present disclosure is represented by the following composition formula (1), Li.sub.aAl.sub.bO.sub.cX.sub.d . . . Formula (1) where values a, b, c, and d are each greater than 0, and X is at least one selected from the group consisting of CI and Br. A battery according to 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 includes the solid electrolyte material according to the present disclosure.

The solid electrolyte material of the present disclosure is made of Li, Ca, Y, Gd, X, and O, where X is at least one selected from the group consisting of F, Cl, Br, and I; and the molar ratio of O to the sum of Y and Gd is greater than O and 0.51 or less.