Solid electrolyte compositions

1. A solid-state electrolyte comprising:

a lithium salt, a lithium ion-conducting inorganic material, a polymer, and a coupling agent, wherein the coupling agent bonds the lithium ion-conducting inorganic material to the polymer.

2. 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 lithium ion-conducting inorganic material has a concentration no less than 40 weight percent and no greater than 95 weight percent relative to the total weight.

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

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

5. The solid-state electrolyte of claim 1 , wherein the coupling agent has a concentration greater than 0 weight percent and no greater than 10 weight percent relative to a total weight of the solid-state electrolyte.

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

7. The solid-state electrolyte of claim 6 , wherein the coupling agent has structure R—(CH 2 ) n —Si—X 3 , wherein n is at least 1, R is an organic group, and X is a hydrolysable group that reacts with the lithium ion-conducting inorganic material.

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

9. 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.

10. The solid-state electrolyte of claim 9 , wherein the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide.

11. The solid-state electrolyte of claim 1 , wherein the polymer comprises PVdF or PEO.

12. The solid-state electrolyte of claim 1 , wherein the lithium 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 , and Li 2 PO 2 N.

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

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

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

16. A solid-state electrolyte comprising:

a lithium salt, a lithium ion-conducting inorganic material, a coupling agent, and a PVdF polymer, wherein the lithium 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 , and Li 2 PO 2 N, and the coupling agent bonds the lithium ion-conducting inorganic material to the PVdF polymer.

17. The solid-state electrolyte of claim 16 , wherein the PVdF 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 lithium ion-conducting inorganic material has a concentration no less than 40 weight percent and no greater than 95 weight percent relative to the total weight.

18. The solid-state electrolyte of claim 16 , wherein the coupling agent has structure R—(CH 2 ) n —Si—X 3 , wherein n is at least 1, R is an organic group, and X is a hydrolysable group that reacts with the lithium ion-conducting inorganic material.

19. The solid-state electrolyte of claim 16 , wherein the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide and the lithium ion-conducting inorganic material comprises Li 1.3 Ti 1.7 Al 0.3 (PO 4 ) 3 .

20. A solid-state electrolyte comprising:

a lithium salt, a lithium ion-conducting inorganic material, a polymer, and a coupling agent, wherein the coupling agent bonds the lithium ion-conducting inorganic material to the polymer, and

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, the lithium ion-conducting inorganic material has a concentration no less than 40 weight percent and no greater than 95 weight percent relative to the total weight, and the coupling agent has a concentration greater than 0 weight percent and no greater than 10 weight percent relative to the total weight.