Rechargeable lithium battery including negative active material

A method of manufacturing a negative active material, the method comprising:

• dipping an SiOx (0<x<2) silicon-based material having Si grains in an Ag dispersion solution to form a resultant product;
• and
• drying the resultant product to form an Ag coating layer having a thickness at 1 nm or 50 nm or between 1 nm and 50 nm,
• wherein the resultant product has a conductivity of greater than or equal to 1.0×103 S/cm,
• wherein the Si grains have an average particle diameter at 5 nm or 50 nm or between 5 nm and 50 nm and are at an interior of a core of the SiOx silicon-based material after the Ag coating layer is formed, and
• wherein the resultant product comprises at 20 wt % or 50 wt % or between 20 wt % and 50 wt % of Ag based on the entire amount of the resultant product.

A rechargeable lithium battery, comprising

• a negative electrode comprising a silicon-based negative active material, the silicon-based negative active material having a conductivity of greater than or equal to 1.0×103 S/cm and comprising a SiOx (0<x<2) core and an Ag continuous or discontinuous coating layer on the core, wherein the core comprises Si grains having an average particle diameter at 1 nm or 100 nm or between 1 nm and 100 nm at an interior of the core, the silicon-based negative active material comprises at 20 wt % or 50 wt % or between 20 wt % and 50 wt % of Ag based on the entire amount of the silicon-based negative active material, and the coating layer has a thickness at 1 nm or 50 nm or between 1 nm and 50 nm;
• a positive electrode comprising a positive active material;
• and
• a non-aqueous electrolyte between the negative electrode and the positive electrode.