Asymmetric anodes for lithium-based energy storage devices

1. A method of making an anode for use in an energy storage device, the method comprising:

providing a current collector comprising an electrically conductive substrate and a surface layer overlaying a first side of the electrically conductive substrate, wherein a second side of the electrically conductive substrate comprises a filament growth catalyst, wherein the second side is opposite the first side;

depositing a lithium storage layer onto the surface layer using a first CVD process; and

forming a plurality of lithium storage filamentary structures on the second side of the electrically conductive substrate using a second CVD process.

2. The method of claim 1 , wherein the first CVD process is a first PECVD process and the second CVD process is a second PECVD process.

3. The method of claim 1 , wherein the lithium storage layer comprises a total content of silicon, germanium, or a combination thereof of at least 40 atomic %.

4. The method of claim 1 , wherein the plurality of lithium storage filamentary structures comprises a total content of silicon, germanium, or a combination thereof of at least 40 atomic %.

5. The method of claim 1 , wherein the first CVD process is different than the second CVD process.

6. The method of claim 1 , wherein the first CVD process is substantially the same as the second CVD process.

7. The method of claim 1 , wherein depositing the lithium storage layer is concurrent with forming the plurality of lithium storage filamentary structures.

8. The method of claim 1 , wherein the surface layer comprises a transition metal oxide.

9. The method of claim 1 , wherein the surface layer comprises a metal chalcogenide comprising at least one of sulfur or selenium.

10. The method of claim 1 , wherein the surface layer has an average thickness in a range of in a range of 0.02 μm to 2 μm.

11. The method of claim 1 , wherein the electrically conductive substrate comprises stainless steel, titanium, nickel, copper, a conductive carbon, or a combination thereof.

12. The method of claim 1 , wherein the electrically conductive substrate comprises:

i) a first electrically conductive layer corresponding to the first side of the electrically conductive substrate;

ii) a second electrically conductive layer corresponding to the second side of the electrically conductive substrate and comprising the filament growth catalyst; and

iii) an electrically insulating layer interposed between the first electrically conductive layer and the second electrically conductive layer.

13. The method of claim 1 , wherein the filament growth catalyst comprises nickel.

14. The method of claim 1 , wherein the lithium storage layer is a continuous porous lithium storage layer having an average density from 1.1 g/cm 3 to 2.25 g/cm 3 and comprising at least 85 atomic % amorphous silicon, and

wherein the lithium storage filamentary structures comprise silicon.

15. A lithium-ion battery comprising the anode made by the method of claim 1 and a cathode.

16. The lithium-ion battery of claim 15 , wherein the lithium storage layer is electrically addressable independently of the plurality of lithium storage filamentary structures.

17. A method of making an anode for use in an energy storage device, the method comprising:

providing a current collector comprising an electrically conductive substrate and a transition metal oxide layer overlaying a first side of the electrically conductive substrate, wherein a second side of the electrically conductive substrate comprises nickel as a filament growth catalyst, and wherein the second side is opposite the first side;

depositing a continuous porous lithium storage layer onto the transition metal oxide layer using a first PECVD process, the continuous porous lithium storage layer having an average density from 1.1 g/cm 3 to 2.25 g/cm 3 and comprising at least 85 atomic % amorphous silicon; and

concurrent with depositing the continuous porous lithium storage layer, forming a plurality of lithium storage filamentary structures on the second side of the electrically conductive substrate using second PECVD process, the plurality of lithium storage filamentary structures comprising a total content of silicon of at least 40 atomic %.