PREPARATION METHOD OF LITHIUM THIOPHOSPHATE
The present disclosure concerns a method for the preparation of lithium thiophosphate, as well as the products obtainable by said methods, and uses thereof especially as solid electrolytes. The method includes preparing a lithium thiophosphate including at least one step for the preparation of a solution S 1 at a temperature T 1 from −200° C. to 10° C. followed by a step for removing at least a portion of the solvent from solution S 1 to obtain lithium thiophosphate. The solution S 1 includes a solvent and at least P species under the form of (PS 4 ) 3− , Li species under the form of Li + , and remaining sulfur under the form of polysulfide. followed by a step for removing at least a portion of the solvent from said solution S 1 to obtain lithium thiophosphate.
1 . A method of preparing a lithium thiophosphate comprising at least one step for the preparation of a solution S 1 at a temperature T 1 from −200° C. to 10° C., the solution S 1 comprising a solvent and at least P species in the form of (PS 4 ) 3− , Li species in the form of Li + , and remaining sulfur in the form of polysulfide, followed by a step for removing at least a portion of the solvent from the solution S 1 to obtain lithium thiophosphate.
2 . The method according to claim 1 , wherein the solution S 1 is obtained by admixing lithium sulfide and phosphorus sulfide in the solvent, at a temperature from −200° C. to 10° C.
3 . The method according to claim 1 , wherein the solution S 1 is obtained from the following steps:
obtaining a precursor solution by admixing lithium sulfide in the solvent;
adding phosphorus sulfide into the precursor solution at a temperature from −200° C. to 10° C.; in order to obtain the solution S 1 .
4 . The method according to claim 1 , wherein the step for removing at least a portion of the solvent from the solution S 1 is carried out at a temperature from 30° C. to 200° C.
5 . The method according to claim 1 , wherein the preparation of the solution S 1 occurs in an inert atmosphere, under vacuum or under H 2 S flow.
6 . The method according to claim 1 , wherein lithium thiophosphate is then thermally treated at a temperature from 150° C. to 700° C.
7 . The method according to claim 1 , wherein the solvent is able to dissolve lithium thiophosphate, lithium sulfide and phosphorus sulfide.
8 . The method according to claim 1 , wherein the solvent is an aliphatic alcohol.
9 . The method according to claim 1 , wherein the solvent is selected from the group consisting of: ethanol, methanol, and mixtures thereof.
10 . The method according to, wherein the temperature T 1 is from −110° C. to 0° C.
11 . The method according claim 1 , wherein the lithium thiophosphate is selected from the group consisting of: Li 3 PS 4 , Li 7 PS 6 , Li 7 P 3 S 11 , and Li 9.6 P 3 S 12 .
12 . The method according to claim 1 , wherein the solution S 1 comprises at least 50% mol. of Li species under the form of Li + , with respect to the total amount in moles of lithium sulfide added in the solvent.
13 . The method according to claim 1 , wherein the solution S 1 comprises at least 50% mol. of P species in the form of (PS 4 ) 3− , with respect to the total amount in moles of phosphorus sulfide added in the solvent.
14 . The method according to claim 1 , wherein the temperature T 1 is from −100° C. to −50° C. and the step for removing at least a portion of the solvent from the solution S 1 is carried out at a temperature comprised from 35° C. to 65° C.
15 . A lithium thiophosphate obtained from the method according to claim 1 .
16 . The method of claim 1 , further comprising, using the obtained lithium thiophosphate as a solid electrolyte.
17 . A solid electrolyte comprising the lithium thiophosphate of claim 15 .
18 . An electrochemical device comprising the solid electrolyte of claim 17 .
19 . A solid state battery comprising the solid electrolyte of claim 18 .
20 . A vehicle comprising the solid state battery of claim 19 .