NEGATIVE ACTIVE MATERIAL FOR SECONDARY BATTERY, AND ELECTRODE AND SECONDARY BATTERY INCLUDING THE SAME

摘要

A negative active material for a secondary battery includes a core carbon material, and a carbide layer formed on at least a portion of an edge of the core carbon material, and has a specific surface area ratio of 1.6 or less and a sphericity ratio of 0.6 or more when the negative active material is compressed with a pressure of 1.3 ton per 1 cm2 for 2 seconds. A secondary battery manufactured using the negative active material can prevent deterioration of characteristics caused by destruction of the carbide layer and deformation of core carbon material that may occur during a compression process performed to manufacture an electrode for the secondary battery. As a result, the secondary battery can be improved in aspect of a discharging capacity, a cycle efficiency and a discharging capacity retention rate at a long cycle.