Amorphous silicon-carbon composite, preparation method therefor, and lithium secondary battery comprising same
An amorphous silicon-carbon composite, a method for preparing the amorphous silicon-carbon composite using a pyrolysis method, a negative electrode for a lithium secondary battery, and a lithium secondary battery including the same.
1. An amorphous silicon-carbon composite, comprising:
silicon and carbon mixed at a molecular level,
wherein the amorphous silicon-carbon composite is in the form of particles having a diameter of 10 nm to 1 μm,
wherein the amorphous silicon-carbon composite is formed by a pyrolysis deposition process for a silicon source and a carbon source,
wherein the amorphous silicon-carbon composite comprises a silicon-carbon covalent bond, a silicon-silicon covalent bond, and a carbon-carbon covalent bond, and
wherein the silicon-carbon covalent bond, the silicon-silicon covalent bond, and the carbon-carbon covalent bond are irregularly present in the amorphous silicon-carbon composite.
2. The amorphous silicon-carbon composite of claim 1 , wherein the amorphous silicon-carbon composite further comprises a heteroatom, and further comprises at least one bond selected from the group consisting of a heteroatom-carbon covalent bond and a heteroatom-silicon covalent bond.
3. The amorphous silicon-carbon composite of claim 2 , wherein the heteroatom comprises at least one selected from the group consisting of boron, phosphorus, nitrogen, and sulfur.
4. The amorphous silicon-carbon composite of claim 1 , wherein the amorphous silicon-carbon composite comprises silicon and carbon in a weight ratio of 3:7 to 7:3.
5. The amorphous silicon-carbon composite of claim 1 , wherein the amorphous silicon-carbon composite has a density of 0.2 g/cc to 0.6 g/cc.
6. A negative electrode for a lithium secondary battery comprising an active material; a conductive material; and a binder, wherein the active material comprises the amorphous silicon-carbon composite of claim 1 .
7. A lithium secondary battery comprising a positive electrode; a negative electrode; a separator interposed between the positive electrode and the negative electrode; and an electrolyte solution, wherein the negative electrode is the negative electrode of claim 6 .