Negative active material for rechargeable lithium battery and rechargeable lithium battery including same
A negative active material for a rechargeable lithium battery, the negative active material including a core having silicon and a first carbon nanotube, an amorphous carbon coating layer surrounding the core, and a second carbon nanotube adhered to the amorphous carbon coating layer.
1 . A negative active material for a rechargeable lithium battery, the negative active material comprising:
a core comprising silicon and a first carbon nanotube;
an amorphous carbon coating layer surrounding the core; and
a second carbon nanotube adhered to the amorphous carbon coating layer,
wherein the second carbon nanotube is positioned on the surface of the negative active material, and
wherein a total amount of the first and second carbon nanotubes is about 0.0001 wt % to 0.009 wt %, based on a total weight of the negative active material.
2 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the first and second carbon nanotubes are each independently a single-walled carbon nanotube, a double-walled carbon nanotube, a multi-walled carbon nanotube, or a combination thereof.
3 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the first carbon nanotube is a single-walled carbon nanotube, and the second carbon nanotube is a multi-walled carbon nanotube.
4 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein an amount of the silicon is about 10% to about 80%, based on a total weight of the negative active material.
5 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein an amount of the silicon is about 10% to about 70%, based on a total weight of the negative active material.
6 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the silicon has an average particle diameter of about 10 nm to about 1,000 nm.
7 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the silicon has an average particle diameter of about 20 nm to about 900 nm.
8 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the amorphous carbon coating layer has a thickness of about 1 nm to about 2 μm.
9 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the amorphous carbon coating layer has a thickness of about 1 nm to about 500 nm.
10 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the amorphous carbon coating layer has a thickness of about 10 nm to about 300 nm.
11 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the amorphous carbon coating layer has a thickness of about 20 nm to about 200 nm.
12 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the amorphous carbon coating layer comprises soft carbon, hard carbon, mesophase pitch carbide, sintered cokes, or a combination thereof.
13 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the second carbon nanotube has an average length of about 1 μm to about 50 μm.
14 . A rechargeable lithium battery, comprising:
a negative electrode including the negative active material as claimed in claim 1 ;
a positive electrode; and
an electrolyte.
15 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein an amount of the first carbon nanotube included in the negative active material is the same as an amount of the second carbon nanotube included in the negative active material.
16 . The negative active material for a rechargeable lithium battery as claimed in claim 1 , wherein the core does not include amorphous carbon.