Silicon-carbon composite powder
A silicon-carbon composite powder having Si and C distributed throughout each particle is provided. The weight ratio of carbon to silicon on the surface of a particle (C/Si) surface is greater than the weight ratio of carbon to silicon within the total particle (C/Si) total . The silicon-carbon composite powder is produced by simultaneously feeding into a reactor a gaseous stream of a SiH 4 , Si 2 H 6 , Si 3 H 8 and/or organosilane and a gaseous stream of at least one hydrocarbon of ethylene, ethane, propane and acetylene and reacting the streams using plasma enhanced chemical vapor deposition.
1. A silicon-carbon composite powder, wherein, for each silicon-carbon composite particle contained in the powder,
a) Si and C are distributed throughout the particle and
b) a weight ratio of carbon to silicon on the particle surface (C/Si) surface is greater than a weight ratio of carbon to silicon within the total particle (C/Si) total , wherein
10≤(C/Si) surface /(C/Si) total ≤50, and
0.3≤(C/Si) total ≤1, wherein the silicon-carbon composite powder has an average diameter of 300 nm or less, and the silicon-carbon composite powder does not exhibit a core shell structure.
2. The silicon-carbon composite powder according to claim 1 wherein Si and C are amorphous.
3. The silicon-carbon composite powder according to claim 1 , obtained by a process comprising:
simultaneously feeding a first gaseous stream of SiH 4 , Si 2 H 6 , Si 3 H 8 and/or an organosilane and a second gas sous stream of at least one hydrocarbon selected from the group consisting of ethylene, ethane, propane and acetylene into a reactor, and
reacting the first and second gaseous streams in the reactor using plasma enhanced chemical vapor deposition.
4. The silicon-carbon composite powder according to claim 3 , wherein
the first gaseous stream is a stream of SiH 4 and/or an organosilane,
a ratio of the at least one hydrocarbon to SiH 4 and/or the organosilane is 0.01-3, and
the at least one hydrocarbon is selected from the group consisting of ethylene, ethane and propane.
5. The silicon-carbon composite powder according to claim 4 , wherein the first gaseous stream is a stream of at least one organosilane selected from the group consisting of CH 3 SiH 3 , (CH 3 ) 2 SiH 2 and (CH 3 ) 3 SiH.
6. A process for manufacturing the silicon-carbon composite powder according to claim 1 , the process comprising:
simultaneously feeding a first gaseous stream of SiH 4 , Si 2 H 6 , Si 3 H 8 and/or an organosilane and a second gaseous stream of at least one hydrocarbon selected from the group consisting of ethylene, ethane, propane and acetylene into a reactor, and
reacting the first and second gaseous streams in the reactor using plasma enhanced chemical vapor deposition.
7. The process according to claim 6 , wherein the first gaseous stream is a stream of SiH 4 and/or organosilane, and a ratio of the at least one hydrocarbon to SiH 4 and/or the organosilane is 0.01-3.
8. The process according to claim 6 , wherein the at least one hydrocarbon is selected from the group consisting of ethylene, ethane and propane.
9. The process according to claim 6 , wherein the first gaseous stream is a stream of at least one organosilane selected from the group consisting of CH 3 SiH 3 , (CH 3 ) 2 SiH 2 and (CH 3 ) 3 SiH.
10. A method for manufacturing a lithium ion battery, the method comprising:
introducing the silicon-carbon composite powder according to claim 1 into the lithium ion battery.