Nanostructured materials for electrochemical conversion reactions
The disclosure is related to battery systems. More specifically, embodiments of the disclosure provide a nanostructured conversion material for use as the active material in battery cathodes. In an implementation, a nanostructured conversion material is a glassy material and includes a metal material, one or more oxidizing species, and a reducing cation species mixed at a scale of less than 1 nm. The glassy conversion material is substantially homogeneous within a volume of 1000 nm 3 .
1. A positive electrode material comprising :
composite particles or nanodomains comprising:
in the discharged state:
a metal component having a median characteristic length scale of between 3 nm and 10 nm and selected from the group consisting of iron, cobalt, manganese, copper, nickel, bismuth, and alloys thereof; and
a lithium fluoride compound intermixed with the metal component, wherein substantially all of the lithium fluoride compound is characterized by an amorphous structure; and
in the charged state:
a metal fluoride component selected from the group consisting of iron fluoride, cobalt fluoride, manganese fluoride, copper fluoride, nickel fluoride, bismuth fluoride, and combinations thereof, wherein substantially all of the metal fluoride component is characterized by an amorphous structure.
2. The positive electrode material of claim 1 , wherein the metal component is iron, manganese, or cobalt and the mole ratio of metal component to lithium fluoride compound is about 1:2 to 1:4.5.
3. The positive electrode material of claim 1 , wherein the metal component is iron.
4. The positive electrode material of claim 1 , wherein the metal fluoride component is iron fluoride.
5. The positive electrode material of claim 1 , wherein the metal component is iron and the metal fluoride component is ferric fluoride.
6. The positive electrode material of claim 1 , wherein the composite particles or nanodomains comprise individual particles of the positive electrode material.
7. The positive electrode of claim 1 , further comprising MoO 3 , MoO 2 , MoS 2 , V 2 O 3 , V 2 O 5 , or combinations thereof.
8. The positive electrode material of claim 1 , wherein the metal component in the composite particles or nanodomains is present as metal nanodomains.
9. The positive electrode material of claim 1 , wherein the positive electrode material further comprises a conductive additive.
10. The positive electrode material of claim 1 , wherein the composite particles or nanodomains further comprise a mixed ion-electron conductor.
11. The positive electrode material of claim 1 , wherein the composite particles or nanodomains further comprise a lithium ion conductor.
12. The positive electrode material of claim 11 , wherein the lithium ion conductor comprises thio-LISICON, garnet, lithium sulfide, FeS, FeS 2 , copper sulfide, titanium sulfide, Li 2 S—P 2 S 5 , lithium iron sulfide, Li 2 S—SiS 2 , Li 2 S—SiS 2 —Al 2 S 3 , Li 2 S—SiS 2 —GeS 2 , Li 2 S—SiS 2 —P 2 S 5 , Li 2 S—P 2 S 5 , Li 2 S—GeS 2 —Ga 2 S 3 , or Li 10 GeP 2 S 12 .
13. The positive electrode material of claim 1 , wherein the metal component has a median characteristic length scale of 5 nm or less.
14. The positive electrode material of claim 1 , wherein the composite particles or nanodomains are substantially homogeneous within a volume of about 1000 nm 3 .
15. The positive electrode material of claim 1 , wherein the metal component is an alloy of iron with cobalt, copper, nickel and/or manganese.
16. The positive electrode material of claim 1 , wherein the lithium fluoride compound comprises lithium oxyfluoride.
17. A solid-state energy storage device comprising the positive electrode material of claim 1 .