Solid electrolyte material and solid-state battery made therewith

1. An Argyrodite-type solid electrolyte material comprising:

Li, T, X and A wherein T is at least one element selected from the group consisting of P, As, Si, Ge, Al, and B; X is one or more halogens or BH 4 , BF 4 , NH 2 , or NO 3 or a blend thereof; A is one or more of S, Se, and N; and the solid electrolyte material has peaks at 2θ=14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° in X-ray diffraction measurement with Cu-Kα(1,2)=1.5418 Å.

2. The solid electrolyte material of claim 1 , further comprising at least one of glass ceramic phases, crystalline phases and mixed phases.

3. The solid electrolyte material of claim 2 wherein a ratio of peak intensity at 2θ=15.3° to a peak at 2θ=17.5° is 1 or more.

4. The solid electrolyte material of claim 1 where the ratio of intensities of a peak at 2θ=15.3°±0.25° to a peak at 14.6°±0.25° is 5:1 or less.

5. The solid electrolyte material of claim 1 , wherein X comprises a blend of one or more halogens or BH 4 , BF 4 , NH 2 , or NO 3 .

6. The solid electrolyte material of claim 1 , comprising a formula LPS·zLiX, where LPS denotes a mixture of Li 2 S and P 2 S 5 in a glass forming ratio or Li 2 S and B 2 S 3 in a glass forming ratio, and LiX represents LiCl, LiBr, LiI, LiBH 4 , LiBF 4 , LiNH 2 , and LiNO 3 , and 0.25≤z≤4.

7. The solid electrolyte material of claim 1 , comprising a formula LPSX·zLiX, where LPSX comprises a mixture of Li 2 S, P 2 S 5 and LiX in a glass forming ratio or Li 2 S, B 2 S 3 and LiX in a glass forming ratio, where LiX comprises one or more of LiCl, LiBr, LiI, LiBH 4 , LiBF 4 , LiNH 2 , and LiNO 3 , and 0<z≤25.

8. The solid electrolyte material of claim 1 , wherein X comprises BH 4 , and wherein the presence of the peak at 2θ=14.6°±0.25 in X-ray diffraction measurement with Cu-Kα(1,2)=1.5418 Å is controlled by tuning the specific synthesis conditions without changing the nominal stoichiometry.

9. The solid electrolyte material of claim 1 comprising a mixture of a crystalline phase having peaks at 2θ=14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° in X-ray diffraction measurement with Cu-Kα(1,2)=1.5418 Å and of one or more of LiBH 4 , LiBF 4 , LiNH 2 , LiNO 3 , LiSCN, LiOCN.

10. The solid electrolyte material of claim 1 comprising a crystalline Argyrodite-type phase comprising 50% or more by mol of total phases present.

11. The solid electrolyte material of claim 1 comprising a primary peak is at 423±10 cm −1 with an intensity ratio of at least 2:1 with other peaks present in the range 250-700 cm −1 in Raman spectroscopic measurements with 532 nm excitation.

12. A lithium battery comprising:

(a) a positive electrode active material layer containing a positive electrode active material;

(b) a negative electrode active material layer containing a negative electrode active material; and

(c) a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer,

wherein at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer comprises a sulfide solid electrolyte material comprising an Argyrodite-type solid electrolyte material comprising: Li, T, X and A wherein T is at least one element selected from the group consisting of P, As, Si, Ge, Al, and B; X is one or more halogens or BH 4 , BF 4 , NH 2 , or NO 3 or a blend thereof; A is one or more of S, Se, and N; and the solid electrolyte material has peaks at 2θ=14.6°±0.25°, 15.3°±0.25°, and 25.1°±0.25° in X-ray diffraction measurement with Cu-Kα(1,2)=1.5418 Å.