BROMINE AND IODINE LITHIUM PHOSPHOROUS SULFIDE SOLID ELECTROLYTE AND SOLID-STATE BATTERY INCLUDING THE SAME

1 . A 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, Sb, W, and B; X is at least one element selected from the group consisting of F, Cl, Br, I and N; and A is one or more of S or Se;

wherein the solid electrolyte material has peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement with Cu-Ka(1,2)=1.5418 Å.

2 . The solid electrolyte material of claim 1 , the material having a formula: Li 1-a-b-c-d P a T b A c X d wherein 0≤a≤0.150, 0≤b≤0.176, 0.364≤c≤0.603, and

0.019≤d≤0.080.

3 . The solid electrolyte material of claim 2 , wherein a=0.130, b=0, c=0.478, d=0.043, A=S, and X=Br and I in a 1:4 ratio by mol.

4 . The solid electrolyte material of claim 1 , further comprising at least one of amorphous phases, crystalline phases and mixed phases.

5 . The solid electrolyte material of claim 1 , wherein the mixed phases may comprise crystalline phases containing peaks at 20.2°±0.50° and 23.6°±0.50°, 21.0°±0.50° and 28.0°±0.50°, 17.5°±0.50° and 18.2°±0.50°, or peaks at 17.8°±0.50° and 21.8°±0.50° in X-ray diffraction measurement with Cu-Ka(1,2)=1.5418 Å.

6 . The solid electrolyte material of claim 5 , wherein a ratio of peak intensity at 20.4°±0.50° to a peak at 21.0°±0.50° is 1 or more.

7 . A solid-state electrochemical cell comprising:

a positive electrode current collector;

a positive electrode layer;

a negative electrode layer; and

a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer,

wherein at least one of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer comprises a 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, Sb, W, and B; X is at least one element selected from the group consisting of F, Cl, Br, I and N; and A is one or more of S or Se; wherein the solid electrolyte material has peaks at 14.9°±0.50°, 20.4°±0.50°, and 25.4°±0.50° in X-ray diffraction measurement with Cu-Ka(1,2)=1.5418 Å.

8 . The solid-state electrochemical cell of claim 7 , wherein the positive electrode current collector comprises aluminum, nickel, titanium, stainless steel, or carbon.

9 . The solid-state electrochemical cell of claim 7 , wherein the positive electrode layer comprises metal oxides, metal phosphates, metal sulfides, sulfur, lithium sulfide.

10 . The solid-state electrochemical cell of claim 9 , wherein the positive electrode layer further comprises a carbon containing material comprising carbon black, graphite, carbon nanotubes, carbon fiber and graphene.

11 . The solid-state electrochemical cell of claim 9 , wherein the positive electrode layer further comprises a binder comprising polyvinyl chloride (PVC) polyanilene, poly(methyl methacrylate) (“PMMA”), nitrile butadiene rubber (“NBR”), styrene-butadiene rubber (“SBR”), PVDF, or polystyrene.

12 . The solid-state electrochemical cell of claim 7 , wherein the negative electrode layer comprises lithium metal, lithium alloys, silicon (Si), tin (Sn), graphitic carbon, and hard carbon.

13 . The solid-state electrochemical cell of claim 12 , wherein the negative electrode layer further comprises a carbon containing material comprising carbon black, graphite, carbon nanotubes, carbon fiber and graphene.

14 . The solid-state electrochemical cell of claim 12 , wherein the negative electrode layer further comprises a binder comprising polyvinyl chloride (PVC) polyanilene, poly(methyl methacrylate) (“PMMA”), nitrile butadiene rubber (“NBR”), styrene-butadiene rubber (“SBR”), PVDF, or polystyrene.