Silicon-carbon composites for lithium-ion battery anodes

Abstract

Silicon-carbon composite structures comprise silicon entities occupying the pores of carbon black supports, in which an IAH:BET surface area ratio for the carbon black support is between 1 and 10 and a mass of silicon per 100 g of carbon black is less than or equal to 0.75 * IAH. Silicon-carbon composites may have a carbon coating. Silicon-carbon composite structures can be prepared by CVD techniques or mechanical mixing and can be used in LIB anodes. Abbreviated figure: Figure 9

Claims

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26. A method according to any one of claims 13 to 17, wherein the silicon-carbon composite has a D50 particle size by volume of between 5 and 25 microns. A method according to any one of claims 13 to 18, wherein the carbon black support has a crystallite size Le less than or equal to 42 Angstroms. A method according to any one of claims 13 to 19, wherein the carbon black carrier has an AHI of between 32 and 400 ml per 100 g of carbon. A method according to any one of claims 13 to 20, wherein the carbon black support has a BET of between 3.2 and 400 m2 / g. The method of any one of claims 13 to 21 further comprises adding graphite to the silicon-carbon composite. The method of any one of claims 13 to 22 further comprising coating the silicon-carbon composite with silicon, carbon or a combination thereof. The method of claim 23, wherein the silicon-carbon composite is coated by chemical vapor deposition. The method of claim 23, wherein the silicon-carbon composite is coated with carbon by thermal decomposition of a carbon-containing precursor on the surface of the silicon-carbon. The method of claim 23, wherein the carbon-containing precursor is a sugar, pitch, tar or soluble gel. [Fig. 2] [Fig. 3] [Fig. 6B] [Fig. 7] [Fig. 9]

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