Pre-lithiated silicon particles and methods of forming the same

A method of making a negative electrode material for an electrochemical cell that cycles lithium ions, the method comprising:

• contacting a first material comprising lithium and having a first temperature and a second material comprising silicon and having a second temperature in a mixing chamber to form a precursor, wherein the first material and the second material each enters the mixing chamber at a pressure greater than or equal to about 10 PSI and the first temperature is at or greater than a melting point temperature of lithium and the second temperature is at or greater than a melting point temperature of silicon;
• adding a metal (M) selected from the group consisting of:
• aluminum (Al), chromium (Cr), titanium (Ti), niobium (Nb), molybdenum (Mo), zirconium (Zr), yttrium (Y), cerium (Ce), and combinations to the precursor and heating the precursor and the metal (M) to form a molten precursor;
• and
• centrifugally distributing the molten precursor by contacting the molten precursor with a rotating surface in a centrifugal atomizing reactor and solidifying the molten precursor to form a plurality of substantially round solid electroactive particles comprising Li4.4xSixMy, where x is greater than 0 to less than or equal to about 0.85 and y corresponds to a weight percent of M that is greater than or equal to 0.1 wt. % to less than or equal to about 10 wt. % and having an average D50 diameter of less than or equal to about 20 micrometers.