Hexacyanometallates as highly conducting solid electrolytes for batteries

1. A solid-state lithium-ion battery, comprising a cathode, an anode, and a solid-state electrolyte disposed between the cathode and the anode, wherein the electrolyte comprises an electrolyte material represented by A x P y [R(CN) 6-w L w ] z , wherein:

A is at least one alkali metal cation,

P is at least one transition metal cation, at least one post-transition metal cation, at least one alkaline earth metal cation, or a combination thereof,

R is at least one transition metal cation,

L is an anion,

x, y, and z are related based on electrical neutrality, and

x>0, y>0, z>0, and 0≤w≤6.

2. The solid-state lithium-ion battery of claim 1 , wherein the anode comprises lithium metal.

3. The solid-state lithium-ion battery of claim 1 , wherein A comprises one or more of Li + , Na + , K + , Rb + and Cs + .

4. The solid-state lithium-ion battery of claim 1 , wherein A comprises Li + .

5. The solid-state lithium-ion battery of claim 1 , wherein A comprises Rb + or Cs + .

6. The solid-state lithium-ion battery of claim 1 , wherein P comprises at least one transition metal cation.

7. The solid-state lithium-ion battery of claim 1 , wherein P comprises cations of at least two different transition metals.

8. The solid-state lithium-ion battery of claim 1 , wherein P comprises at least one post-transition metal cation.

9. The solid-state lithium-ion battery of claim 1 , wherein P comprises at least one alkaline earth metal cation.

10. The solid-state lithium-ion battery of claim 1 , wherein P comprises at least one alkaline earth metal cation, and wherein A comprises Rb + or Cs + .

11. The solid-state lithium-ion battery of claim 1 , wherein R is selected from cations of Fe, Mn, Cr, and Co.

12. The solid-state lithium-ion battery of claim 1 , wherein the electrolyte material is represented by A x P y [Fe(CN) 6 ] z .

13. The solid-state lithium-ion battery of claim 1 , wherein the electrolyte material has an ionic conductivity of about 10 −4 S/cm or more.

14. The solid-state lithium-ion battery of claim 1 , wherein the electrolyte material has an electronic conductivity of about 10 −8 S/cm or less.

15. The solid-state lithium-ion battery of claim 1 , wherein the electrolyte material maintains its electronic conductivity when a voltage of up to 5 V is applied across the electrolyte material.

16. The solid-state lithium-ion battery of claim 1 , wherein the electrolyte material is chemically stable when cycled in contact with lithium metal between 0 and 5 V versus Li/Li + , and wherein the electrolyte material is substantially electrochemically inactive during operation of the battery.

17. The solid-state lithium-ion battery of claim 1 , wherein the battery is substantially free of a liquid electrolyte or a polymer electrolyte.

18. The solid-state lithium-ion battery of claim 1 , wherein the battery is substantially free of an electrode comprising a hexacyanometallate.

19. The solid-state lithium-ion battery of claim 1 , wherein w=0.

20. The solid-state lithium-ion battery of claim 1 , wherein the electrolyte material accounts for at least about 50 wt. % of the solid-state electrolyte.

21. A solid-state lithium-ion battery, comprising a cathode, a lithium metal anode, and a solid-state electrolyte disposed between the cathode and the lithium metal anode, wherein the solid-state electrolyte comprises at least about 50 wt. % of an electrolyte material represented by A x P y [R(CN) 6 ] z , wherein:

A is at least one alkali metal cation,

P is at least one transition metal cation, at least one post-transition metal cation, at least one alkaline earth metal cation, or a combination thereof,

R is at least one transition metal cation,

x, y, and z are related based on electrical neutrality, and

x>0, y>0, z>0.

22. An electric vehicle comprising the solid-state lithium-ion battery of claim 21 .