Negative active material for lithium secondary battery, method of preparing the same and lithium secondary battery comprising the same

Abstract

A negative active material for a lithium secondary battery includes a crystalline graphite core and a carbon shell. The carbon shell includes at least one material selected from a transition metal, an alkali metal, an alkaline earth metal, an element of Group 3B of the Periodic table, an element of Group 4B, an element of Group 5B or a mixture thereof. The carbon shell is a turbostratic carbon layer, or am amorphous or crystalline carbon layer having different physical properties from the core. The negative active material can be used in a lithium secondary battery such that the battery has a large discharge capacity and a high charge/discharge efficiency.