High capacity electrode materials for batteries and process for their manufacture
The present invention provides a nanostructured metal oxide material for use as a component of an electrode in a lithium-ion or sodium-ion battery. The material comprises a nanostructured titanium oxide or vanadium oxide film on a metal foil substrate, produced by depositing or forming a nanostructured titanium dioxide or vanadium oxide material on the substrate, and then charging and discharging the material in an electrochemical cell from a high voltage in the range of about 2.8 to 3.8 V, to a low voltage in the range of about 0.8 to 1.4 V over a period of about 1/30 of an hour or less. Lithium-ion and sodium-ion electrochemical cells comprising electrodes formed from the nanostructured metal oxide materials, as well as batteries formed from the cells, also are provided.
1. A crystalline nanostructured metal oxide material for use as a component of an electrode in a lithium-ion battery; wherein the crystalline nanostructured metal oxide material is produced by electrochemical anodization of a surface of a titanium foil substrate to form an amorphous film of TiO 2 nanotubes, subsequently drying the amorphous film to remove water, and then charging and discharging the amorphous film in a lithium electrochemical cell from a high voltage in the range of about 2.6 to 3 V, to a low voltage in the range of about 0.7 to 1 V, over a period of about 1/30 of an hour or less.
2. The nanostructured metal oxide material of claim 1 wherein the titanium dioxide nanotubes comprise densely packed TiO 2 , nanotubes oriented perpendicular to the surface of the titanium foil substrate.
3. The nanostructured metal oxide material of claim 2 wherein the densely packed TiO 2 nanotubes have a wall thickness of about 8 to 12 nm and an outer tubular diameter of about 50 to 70 nm.
4. The nanostructured metal oxide material of claim 2 wherein the densely packed TiO 2 nanotubes have a wall thickness of about 18 to 25 nm and an outer tubular diameter of about 100 to 150 nm.
5. A lithium-ion electrochemical cell comprising a cathode, an anode and a nonaqueous lithium-containing electrolyte therebetween, wherein the anode comprises the nanostructured metal oxide material of claim 1 .
6. A lithium-ion battery comprising a plurality of electrochemically linked electrochemical cells of claim 5 .