Lithiated transition metal oxides
Process for the fabrication of an electrode structure comprising an electrochemically active material suitable for use in an energy storage device. The method includes electrodepositing the electrochemically active material onto an electrode in electrodeposition bath containing a non-aqueous electrolyte. The electrode structure can be used for various applications such as electrochemical energy storage devices including high power and high-energy lithium-ion batteries.
1. A method of forming a lithiated transition metal oxide comprising the steps of:
immersing a working electrode into a non-aqueous electrolyte comprising a lithium source and a transition metal source,
electrodepositing a lithiated transition metal oxide onto a surface of the working electrode from the electrolyte at a temperature in excess of the melting temperature of the non-aqueous electrolyte,
removing the working electrode from the bath and
rinsing the electrodeposited lithiated transition metal oxide.
2. The method of claim 1 wherein the non-aqueous electrolyte comprises an organic molten salt, an inorganic molten salt, or a combination thereof.
3. The method of claim 2 wherein a majority of ions comprised by the non-aqueous electrolyte are inorganic ions.
4. The method of claim 1 wherein at least 99% of ions comprised by the non-aqueous electrolyte are inorganic ions.
5. The method of claim 1 wherein the non-aqueous electrolyte comprises a molten acetate salt, a molten carbonate salt, a molten sulfide salt, a molten silicate, a molten aluminate, a molten hydroxide salt, a molten halide salt, a molten nitrate salt, a molten nitrite salt, a molten sulfate salt or a combination thereof.
6. The method of claim 1 wherein the non-aqueous electrolyte comprises a hydroxide salt selected from the group consisting of LiOH, KOH, NaOH, RbOH, and CsOH, a halide salt selected from the group consisting of LiCl, LiF, KF, KCl, NaCl, NaF, LiBr, NaBr, KBr, LiI, NaI, KI, and AlCl 3 , and a nitrate salt selected from the group consisting of LiNO 3 , NaNO 3 , and KNO 3 , and combinations thereof.
7. The method of claim 1 wherein the non-aqueous electrolyte comprises a nitrite salt selected from the group consisting of LiNO 2 , NaNO 2 , KNO 2 , and combinations thereof.
8. The method of claim 1 wherein the working electrode is selected from the group consisting of metals, metal alloys, ceramics, carbon, electrically conductive polymers, and electrically conductive composite materials.
9. The method of claim 1 wherein the working electrode is selected from the group consisting of aluminum, copper, chromium, cobalt, manganese, nickel, silver, gold, tin, platinum, palladium, zinc, tungsten, tantalum, rhodium, molybdenum, titanium, iron, zirconium, vanadium, and hafnium, and alloys thereof.
10. The method of claim 1 wherein the working electrode is selected from the group consisting of conductive carbon particles, carbon nanotubes, carbon fibers, fullerenes, graphene, graphite, pyrolitic carbon, and glassy carbon.
11. The method of claim 1 wherein the lithiated transition metal oxide ceramic is electrodeposited onto the surface(s) of a three-dimensional working electrode having an open pore porous structure.
12. The method of claim 1 wherein the working electrode has a void volume fraction (porosity) of at least about 90%.
13. The method of claim 1 wherein the working electrode is an electrically conductive porous structure comprising unit cells having an average size in the range of about 10 nm to about 100 μm.
14. The method of claim 1 wherein the working electrode is an electrically conductive porous structure comprising unit cells having an average size in the range of about 10 nm to about 10 μm.
15. The method of claim 1 wherein the working electrode has a thickness of at least 30 μm.
16. The method of claim 1 wherein the lithiated transition metal oxide is conformally coated onto the working electrode.
17. The method of claim 1 wherein the source of the transition metal in the plating bath comprises an oxide, halide or sulfate of at least one transition metal.
18. The method of claim 1 wherein the electrodeposition is carried out at a temperature in the range of about 100 to about 600° C.
19. The method of claim 1 wherein the electrodeposition is carried out at a temperature in the range of about 200 to about 600° C.
20. The method of claim 1 wherein the electrodeposition is carried out at a temperature in the range of about 300 to about 400° C.
21. The method of claim 1 wherein electrodeposition is carried out at a pressure of less than 2 atmospheres.
22. The method of claim 1 wherein the electrodeposition is carried out at atmospheric pressure.
23. The method of claim 1 wherein the thickness of the electrodeposited lithiated transition metal oxide ranges from 10 nm to 100 μm.
24. The method of claim 1 wherein the electrodeposited lithiated transition metal oxide is lithium cobalt oxide characterized by a Raman spectrum containing a peak at approximately 680 cm −1 .