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

Provided is a negative electrode active material which includes: a silicon-based core; and an outer coating layer formed on the silicon-based core and including polyimide, wherein the polyimide comprises a fluorine-containing imide unit. The outer coating layer may be included in an amount of more than 0 wt % and 4.5 wt % or less in the negative electrode active material.