Anodes for lithium-based energy storage devices
An anode for a lithium-based energy storage device such as a lithium-ion battery is disclosed. The anode includes an electrically conductive current collector comprising an electrically conductive layer and a transition metal oxide layer overlaying the electrically conductive layer. The anode may include a continuous porous lithium storage layer provided over the transition metal oxide layer. The continuous porous lithium storage layer may include at least 80 atomic % silicon. A method of making the anode may include providing an electrically conductive current collector having an electrically conductive layer and a transition metal oxide layer provided over the electrically conductive layer. A continuous porous lithium storage layer is deposited over the transition metal oxide layer by PECVD. The continuous porous lithium storage layer has a total content of silicon of at least 80 atomic %.
1. A method of making an anode for use in an energy storage device, the method comprising:
providing an electrically conductive current collector comprising an electrically conductive layer and a transition metal oxide layer overlaying over the electrically conductive layer; and
depositing a continuous porous lithium storage layer onto the transition metal oxide layer by PECVD, wherein the continuous porous lithium storage layer has a total content of silicon of at least 80 atomic %.
2. The method of claim 1 , wherein the PECVD comprises an expanding thermal chemical vapor deposition plasma process.
3. The method of claim 1 , wherein the PECVD comprises using a microwave source or an AC source.
4. The method of claim 1 , wherein the transition metal oxide layer has an average thickness of at least 0.02 μm.
5. The method of claim 1 , wherein the transition metal oxide layer comprises an oxide of nickel, an oxide of titanium, or an oxide of copper.
6. The method of claim 1 , wherein the continuous porous lithium storage layer has an average thickness in a range of 2 μm to 15 μm.
7. The method of claim 1 , wherein the continuous porous lithium storage layer has a total content of silicon of at least 90 atomic %.
8. The method of claim 1 , wherein the continuous porous lithium storage layer further comprises 0.1 to 10 atomic % of a silicide forming metallic element.
9. The method of claim 1 , wherein the continuous porous lithium storage layer further comprises 0.2 to 5 atomic % of a silicide forming metallic element.
10. The method of claim 1 , wherein the continuous porous lithium storage layer has an average density in a range of 1.1 to 2.25 g/cm 3 .
11. The method of claim 1 , further comprising forming the transition metal oxide layer by sputtering.
12. The method of claim 1 , further comprising forming the transition metal oxide layer by evaporation.
13. The method of claim 1 , further comprising forming the transition metal oxide layer by CVD.
14. The method of claim 1 , further comprising forming the transition metal oxide layer by ALD.
15. The method of claim 1 , further comprising forming a supplemental layer over the continuous porous lithium storage layer.
16. The method of claim 15 , wherein forming the supplemental layer comprises ALD, CVD, PECVD, evaporation, or sputtering.
17. The method of claim 15 , wherein forming the supplemental layer comprises solution coating or ink jet deposition.
18. The method of claim 15 , wherein the supplemental layer comprises a solid-state electrolyte.
19. The method of claim 1 , wherein the electrically conductive layer is in the form of a metal foil or metal mesh and comprises stainless steel, nickel, copper, or titanium.
20. An anode made by the method of claim 1 , wherein:
the silicon comprises amorphous silicon, and
the continuous porous lithium storage layer has interstices embedded therein.