Silicon composite cluster and carbon composite thereof, and electrode, lithium battery, and electronic device each including the same

A silicon-containing composite comprising:

• a core comprising a porous silicon composite secondary particle;
• and
• a shell on and surrounding the core;
• wherein the porous silicon composite secondary particle comprises an aggregate of silicon composite primary particles, each comprising a silicon suboxide, a thermal treatment product of the silicon suboxide, or a combination thereof;
• and
• a first graphene on a surface of the silicon suboxide, or the thermal treatment product of the silicon suboxide, and
• the silicon composite primary particles are in a form of a nanowire, a needle, a rod, a nanotube, a nanorod, a wafer, a nanoribbon, or a combination thereof;
• wherein the shell comprises a second graphene, and the first graphene and the second graphene comprise at least one element of nitrogen, phosphorus, and sulfur, and
• wherein an amount of the at least one element of nitrogen, phosphorus, and sulfur in the second graphene shell is about 0.05 atomic percent to about 0.2 atomic percent at a surface depth of 10 nanometers or less from a surface of the second graphene shell of the secondary particle, as analyzed by X-ray photoelectron spectroscopy,
• wherein the silicon-containing composite comprises a first core/shell structure and a second core/shell structure,
• the first core/shell structure comprises the porous core comprising the porous silicon composite secondary particle and the second graphene shell on the surface of the porous core, wherein a thickness of the second graphene shell is 10 nm to 5000 nm, and
• the second core/shell structure comprises a core comprising the silicon and the silicon suboxide on the surface of the silicon, and the shell of the second core/shell structure comprises the first graphene disposed primarily within the porous core of the silicon-containing composite and on the surface of the silicon suboxide, and the second graphene has a higher density than the first graphene.