Multi-phase, silicon-containing electrode for a lithium-ion battery

A lithium-ion battery comprising:

• (a) an anode comprising particles having an average particle size ranging from 1 μm to 50 μm, said particles comprising an amorphous electrochemically active phase and an electrochemically inactive phase that share at least one common phase boundary, said electrochemically active phase comprising elemental silicon and said electrochemically inactive phase comprising at least two metal elements in the form of an intermetallic compound, a solid solution, or combination thereof, wherein
• one of the metal elements in said electrochemically inactive phase is aluminum;
• (b) a cathode;
• and
• (c) an electrolyte separating the anode and the cathode.

A method for preparing an electrode composition for a lithium-ion battery comprising:

• (a) melting together elemental silicon and two or more additional metal elements in an inert atmosphere to form an ingot;
• (b) melting the ingot in an inert atmosphere to form a molten stream;
• (c) rapidly quenching the molten stream on the surface of a rotating wheel to form a ribbon;
• (d) pulverizing the ribbon to form particles having an average particle size ranging from 1 μm to about 50 μm,
• (e) coating the particles onto a current collector to form an electrode;
• (f) incorporating the electrode into a lithium-ion battery:
• and
• (g) cycling the battery at least one time through at least one charge-discharge cycles at a voltage greater than 50mV vs. Li/Li+, wherein
• said particles, after cycling, comprising an amorphous electrochemically active phase and an electrochemically inactive phase that share at least one common phase boundary, said electrochemically active phase comprising elemental silicon and said electrochemically inactive phase comprising at least two metal elements in the form of an intermetallic compound, a solid solution, or combination thereof, wherein
• one of the metal elements in said electrochemically inactive phase is aluminum.