Composite electrode materials and methods of making the same

A method of making a composite electrode material, the method comprising:

• providing a plurality of silicon particles, with each silicon particle having a surface;
• depositing a metal catalyst layer on the surface of each silicon particle to form a plurality of precursor structures;
• dispersing the precursor structures in an organic polymeric material to form a precursor electrode material;
• and
• heating the precursor electrode material in an inert environment:
• (i) to convert the organic polymeric material into a carbon-based material, (ii) to convert at least a portion of the metal catalyst layer on the surface of each silicon particle into a metal silicide, and (iii) to form a graphitic shell around each silicon particle.

A method of making a composite negative electrode material for a lithium-ion battery, the method comprising:

• providing a plurality of silicon particles, with each silicon particle having a surface;
• depositing a metal catalyst layer on the surface of each silicon particle to form a plurality of precursor structures;
• dispersing the precursor structures in an organic polymeric material to form a precursor electrode material;
• and
• heating the precursor electrode material in an inert environment to pyrolyze the organic polymeric material and transform the precursor electrode material into a composite electrode material that includes a carbon-based matrix component and a silicon-based particulate component embedded in the carbon-based matrix component,
• wherein the silicon-based particulate component includes a plurality of core-shell structures, with each core-shell structure including a silicon core, an intermetallic layer overlying the core, and a graphitic shell surrounding the silicon core and the intermetallic layer.