Solid electrolyte compositions

1. A solid-state electrolyte comprising:

a lithium salt, particles of a lithium ion-conducting inorganic material, particles of a non ion-conducting polymer, and a coupling agent;

wherein the particles of the non ion-conducting polymer are dispersed throughout the particles of the lithium ion-conducting inorganic material, and the coupling agent bonds the ion-conducting inorganic material to the polymer, and

wherein the solid-state electrolyte is solvent free and unsintered.

2. The solid-state electrolyte of claim 1 , wherein the coupling agent comprises a metal and an organic group.

3. The solid-state electrolyte of claim 1 , wherein the coupling agent comprises silicon.

4. The solid-state electrolyte of claim 1 , wherein the coupling agent comprises titanium.

5. The solid-state electrolyte of claim 1 , wherein the coupling agent is trifunctional.

6. The solid-state electrolyte of claim 1 , wherein the coupling agent comprises 3-(trimethoxy silyl)propyl methacrylate.

7. The solid-state electrolyte of claim 1 , wherein the lithium salt is selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imide, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium bis(oxalato)borate, lithium chlorate, lithium bis(fluorosulfonyl)imide, and lithium triflate.

8. The solid-state electrolyte of claim 7 , wherein the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide.

9. The solid-state electrolyte of claim 1 , wherein the polymer comprises

PVdF.

10. The solid-state electrolyte of claim 1 , wherein the ion-conducting inorganic material is selected from the group consisting of Li 1.3 Ti 1.7 Al 0.3 (PO 4 ) 3 , Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12 , Li 10 SnP 2 S 12 , P 2 S 5 —Li 2 S glass, Li 1+x+y Al x Ti 2−x Si y P 3−y O 12 , or Li 2 PO 2 N.

11. The solid-state electrolyte of claim 1 , wherein the ion-conducting inorganic material comprises a phosphate group.

12. The solid-state electrolyte of claim 1 , wherein the ion-conducting inorganic material comprises Li 1.3 Ti 1.7 Al 0.3 (PO 4 ) 3 .

13. The solid-state electrolyte of claim 1 , wherein the polymer comprises PVdF, the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide, and the ion-conducting inorganic material comprises Li 1.3 Ti 1.7 Al 0.3 (PO 4 ) 3 .

14. A solid-state electrolyte comprising:

a lithium salt, particles of an ion-conducting inorganic material, a coupling agent, and particles of a non ion-conducting polymer, wherein the particles of the non ion-conducting polymer are dispersed throughout the particles of the lithium ion-conducting inorganic material, wherein the solid-state electrolyte is solvent free and unsintered;

wherein the ion-conducting inorganic material is selected from the group consisting of Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12 , Li 10 SnP 2 S 12 , P 2 S 5 —Li 2 S glass, Li 1+x+y Al x Ti 2−x Si y P 3−y O 12 , or Li 2 PO 2 N, and wherein the coupling agent bonds the ion-conducting inorganic material to the polymer.

15. The solid-state electrolyte of claim 14 , wherein the ion-conducting inorganic material comprises Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12 .

16. The solid-state electrolyte of claim 14 , wherein the ion-conducting inorganic material comprises Li 10 SnP 2 S 12 .

17. The solid-state electrolyte of claim 14 , wherein the ion-conducting inorganic material comprises P 2 S 5 —Li 2 S glass.

18. The solid-state electrolyte of claim 14 , wherein the ion-conducting inorganic material comprises Li 1+x+y Al x Ti 2−x Si y P 3−y O 12 .

19. The solid-state electrolyte of claim 14 , wherein the ion-conducting inorganic material comprises Li 2 PO 2 N.

20. The solid-state electrolyte of claim 1 , wherein the polymer has a concentration no less than 2 weight percent and no greater than 15 weight percent relative to a total weight of the solid-state electrolyte, and the inorganic ion-conducting material has a concentration no less than 40 weight percent and no greater than 95 weight percent relative to the total weight.