Intermediate layers for electrode fabrication
An electrode includes one or more intermediate layers positioned between a substrate and an electrochemically active material. Intermediate layers may be made from chromium, titanium, tantalum, tungsten, nickel, molybdenum, lithium, as well as other materials and their combinations. In certain embodiments, an active material includes one or more high capacity active materials, such as silicon, tin, and germanium. These materials tend to swell during cycling and may loose mechanical and/or electrical connection to the substrate. A flexible intermediate layer may compensate for swelling and provide a robust adhesion interface. Methods of fabricating electrodes involve forming metal silicide nanostructures.
1. A method of manufacturing a battery electrode for use in a lithium ion battery, the method comprising:
providing a substrate having a metal surface;
decomposing a silicon-containing gas to form silicon or silicon-containing material;
alloying the silicon or silicon-containing material with the metal surface to form metal silicide nanostructures, wherein the metal silicide nanostructures are attached directly to the substrate; and
after forming the metal silicide nanostructures, depositing amorphous silicon on the metal silicide nanostructures.
2. The method of claim 1 , wherein the metal is nickel and the metal silicide is nickel silicide.
3. The method of claim 1 , wherein the substrate comprises a layer of the metal, the layer of metal comprising the metal surface.
4. The method of claim 1 , further comprising, prior to exposing the substrate to silicon-containing gas, roughening the metal surface.
5. The method of claim 1 , wherein the silicon-containing gas is silane (SiH 4 ).
6. The method of claim 1 , wherein the silicon-containing gas is a chlorosilane.
7. The method of claim 1 , wherein the metal silicide nanostructures are nanowires.
8. A method of manufacturing a battery electrode for use in a lithium ion battery, the method comprising:
providing a nickel substrate;
exposing the nickel substrate to a silicon-containing gas;
reacting nickel in the nickel substrate with the silicon-containing gas to form nickel silicide nanowires; and
coating the nickel silicide nanowires with amorphous silicon.
9. The method of claim 8 , wherein the silicon-containing gas is silane (SiH 4 ).
10. The method of claim 8 , wherein the silicon-containing gas is a chlorosilane.