CPC H01M 4/1395 (2013.01) [C01B 33/021 (2013.01); C01B 33/06 (2013.01); H01M 4/1393 (2013.01); H01M 4/366 (2013.01); H01M 4/386 (2013.01); H01M 4/625 (2013.01); H01M 10/0525 (2013.01)] | 18 Claims |
1. A method of forming a silicon material for use in anodes of batteries, the method comprising:
reacting a metal or a mixture of multiple metals with silicon (Si) in a solid state reaction to form a metal silicide;
performing a CO2-thermic oxidation process on the formed metal silicide with carbon dioxide to form a composite of one or more metal oxides, silicon, and carbon; and
contacting the formed composite of one or more metal oxides, silicon, and carbon with an acid to remove the one or more metal oxides from the composite to produce particles of the silicon material individually having: a crystalline silicon formed in the CO2-thermic oxidation process; and pores in the crystalline silicon, the pores corresponding to the removed metal oxide by the acid and having surfaces coated with the carbon from the performed CO2-thermic oxidation process,
wherein reacting the metal or the mixture of multiple metals with silicon includes reacting one of magnesium (Mg), calcium (Ca), or barium (Ba) with silicon (Si); and performing the CO2-thermic oxidation process includes performing the CO2-termic oxidation process with one of magnesium silicide (Mg2Si), calcium (CaSi2), and barium silicide (BaSi2) and wherein in case Mg is present, Mg is at least 10 wt % more in excess of silicon.
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