Structured silicon anode
A battery can be fabricated from a substrate including silicon. This allows the battery to be produced as an integrated unit. The battery includes an anode formed from an array of spaced elongated structures, such as pillars, which include silicon and which can be fabricated on the substrate. The battery also includes a cathode which can include lithium.
1. A method of fabricating an energy storage device comprising the steps of:
forming an anode comprising an array of spaced elongated structures extending from a substrate, wherein the elongated structures comprise silicon;
forming a cathode; and
arranging the anode and cathode in communication to form a battery.
2. A method of fabricating a device according to claim 1 in which the anode is arranged to tolerate the conditions occasioned by the volume changes caused by charging/discharging of the battery.
3. A method according to claim 1 in which the anode is arranged to maintain structural integrity throughout a cycling of the battery.
4. A method according to claim 3 wherein the elongated structures maintain structural integrity after 50 cycles of the battery.
5. A method according to claim 1 in which the anode is arranged to withstand repeated volume expansion associated with alloying during use of the battery.
6. A method according to claim 1 further comprising the step of arranging the elongated structures to not exceed a fractional coverage of 0.5 of the substrate.
7. A method according to claim 1 wherein the step of forming the elongated structures comprises forming elongated structures which are 0.1 to 1.0 microns in diameter.
8. A method according to claim 1 wherein the step of forming a cathode comprises forming a lithium-comprising cathode and further comprising providing an electrolyte comprising lithium for the battery.
9. A method according to claim 1 wherein the array is one of a scattered distribution or a regular array.
10. A method according to claim 1 wherein the elongated structures comprise pillars having a surface area of about 4 FH/d times the substrate area wherein F is the surface fractional coverage, H is the height of the pillar and d is the diameter of the pillar.
11. A method of fabricating an energy storage device comprising the steps of:
forming an anode comprising:
providing a substrate comprising silicon,
removing material from the substrate to form a plurality of spaced pillars on the substrate;
forming a cathode; and
arranging the anode and cathode in communication to form a battery.
12. A method of fabricating a device according to claim 11 in which the anode is arranged to tolerate the conditions occasioned by the volume changes caused by charging/discharging of the battery.
13. A method according to claim 11 in which the anode is arranged to maintain structural integrity throughout a cycling of the battery.
14. A method according to claim 11 in which the anode is arranged to withstand repeated volume expansion associated with alloying during use of the battery.
15. A method according to claim 11 further comprising the step of arranging the pillars to not exceed a fractional coverage of 0.5 of the substrate.
16. A method according to claim 11 wherein the step of forming the pillars comprises forming pillars which are 0.1 to 1.0 microns in diameter.
17. A method according to claim 11 wherein the step of forming a cathode comprises forming a lithium-comprising cathode.
18. A method according to claim 17 further comprising providing an electrolyte comprising lithium for the battery.
19. A method according to claim 17 further comprising providing an electrolyte comprising a lithium-based salt in a solvent for the battery.
20. A method according to claim 11 further comprising providing a polymer electrolyte for the battery.
21. A method according to claim 11 wherein the step of forming the pillars comprises forming pillars having a surface area of about 4 FH/d times the substrate area wherein F is the surface fractional coverage, H is the height of the pillar and d is the diameter of the pillar.
22. A method of fabricating an energy storage device comprising the steps of:
forming an anode comprising a plurality of spaced elongated structures each mounted at one end to a substrate and extending away therefrom, wherein the elongated structures comprise silicon;
forming a cathode; and
arranging the anode and cathode in communication to form a battery.
23. A method of fabricating a device according to claim 22 in which the anode is arranged to tolerate the conditions occasioned by the volume changes caused by charging/discharging of the battery.
24. A method according to claim 22 in which the anode is arranged to maintain structural integrity throughout a cycling of the battery.
25. A method according to claim 22 wherein the elongated structures maintain structural integrity after 50 cycles of the battery.
26. A method according to claim 22 in which the anode is arranged to withstand repeated volume expansion associated with alloying during use of the battery.
27. A method according to claim 22 further comprising the step of arranging the elongated structures to not exceed a fractional coverage of 0.5 of the substrate.
28. A method according to claim 22 wherein the step of forming the elongated structures comprises forming elongated structures which are 0.1 to 1.0 microns in diameter.
29. A method according to claim 22 wherein the step of forming a cathode comprises forming a lithium-comprising cathode.
30. A method according to claim 29 further comprising providing an electrolyte comprising lithium for the battery.
31. A method according to claim 29 further comprising providing an electrolyte comprising a lithium-based salt in a solvent for the battery.
32. A method according to claim 22 further comprising providing a polymer electrolyte for the battery.
33. A method according to claim 22 wherein the elongated structures comprise pillars having a surface area of about 4 FH/d times the substrate area wherein F is the surface fractional coverage, H is the height of the pillar and d is the diameter of the pillar.