Solid state electrolyte and method of production
A process for preparing a solid electrolyte that includes mixing a lithium source with a sulfur source and a compound containing phosphorous and sulfur to form a composite, then heating the composite to the melting point of the compound containing phosphorous and sulfur to form the solid electrolyte material. A solid electrolyte material prepared by the process, wherein the solid electrolyte material is of formula I, which is Li (7-y-z) PS (6-y-z) X (y) W (z) wherein X and W are individually selected from F, Cl, Br, and I; where y and z each individually range from 0 to 2; and where y+z ranges from 0 to 2.
1 . A process for preparing a solid electrolyte comprising:
a) mixing one or more lithium sources with a sulfur source and a compound containing phosphorous and sulfur to form a homogeneous composite, wherein the compound containing phosphorus and sulfur is present in a molar excess as compared to the sulfur source and the one or more lithium sources; and
b) heating the homogeneous composite to a melting point of the compound containing phosphorous and sulfur to form the solid electrolyte to form a molten reactive flux, wherein the compound containing phosphorous and sulfur is a liquid and the one or more lithium sources and the sulfur source are solid.
2 . The process of claim 1 , wherein the one or more lithium source comprises Li 2 CO 3 , a lithium halide, LiNO 3 , LiOH, Li 2 SO 3 , Li 3 N, Li 2 NH, LiNH 2 , LiBF 4 , LiBH 4 , Li 2 O, Li 3 PO 4 , LiBO 2 , Li 2 B 4 O 7 , Li 2 ZrO 3 , LiAlO 2 , Li 2 TiO 3 , LiNbO 3 , Li 2 SiO 3 , or a mixture thereof.
3 . The process of claim 2 , wherein the lithium halide is selected from the group consisting of LiF, LiCl, LiBr, LiI, and mixtures thereof.
4 . The process of claim 1 further comprising simultaneously mixing the homogeneous composite while heating.
5 . The process of claim 1 , wherein the compound containing phosphorous and sulfur comprises a formula P 4 S X , wherein x ranges from 3 to 10.
6 . The process of claim 1 , wherein the compound containing phosphorous and sulfur comprises P 2 S 5 .
7 . The process of claim 1 , wherein the homogeneous composite in step b) is heated to a temperature from about 150° C. and about 600° C.
8 . The process of claim 1 , wherein the homogeneous composite in step b) is heated to a temperature from about 150° C. to about 200° C.
9 . The process of claim 1 , wherein the homogeneous composite in step b) is heated to a temperature from about 250° C. to about 300° C.
10 . The process of claim 1 , wherein the sulfur source comprises elemental sulfur, sulfur vapor, a polysulfide, H 2 S gas, or a mixture thereof.
11 . The process of claim 1 , wherein the sulfur source comprises elemental sulfur.
12 . The process of claim 1 , wherein the solid electrolyte comprises formula I:
Li (7-y-z) PS (6-y-z) X (y) W (z) (I)
wherein:
X and W are each individually selected from F, Cl, Br, and I;
y and z each individually range from 0 to 2; and
wherein y+z ranges from 0 to 2.
13 . The process of claim 12 , wherein the solid electrolyte of Formula I is selected from Li 3 PS 4 , Li 4 P 2 S 6 , Li 7 P 3 S 11 , Li 5.5 PS 4.5 Cl 1.5 , Li 5.5 PS 4.5 ClBr 0.5 , Li 5 PS 4 Cl 2 , and Li 5 PS 4 ClBr.
14 . The process of claim 1 , wherein the solid electrolyte comprises Formula II:
Li (7-y-z) PS (6-y-z-u) O u X (y) W (z) (II)
wherein:
X and W are each individually selected from F, Cl, Br, and I;
y and z each individually range from 0 to 2;
u ranges from about 0 to about 6; and
wherein y+z ranges from 0 to 2.
15 . The process of claim 14 , wherein the solid electrolyte of Formula II is selected from Li 3 PS 3.9 O 0.1 , Li 3 PS 3.5 O 0.5 , Li 6 PS 4.8 O 0.3 Cl, Li 6 PS 4.7 O 0.3 Br, Li 5.5 PS 4.1 O 0.4 Cl 1.5 , and Li 5.5 PS 3.5 OClBr 0.5 .
16 . The process of claim 1 , wherein the lithium source comprises Li 2 CO 3 .
17 . The process of claim 1 , wherein the lithium source comprises two lithium sources including Li 2 CO 3 and LiCl.