CYLINDRICAL SECONDARY BATTERY INCLUDING STRUCTURE CONFIGURED TO BLOCK LASER BEAM FOR WELDING AND BATTERY PACK INCLUDING THE SAME

A cylindrical secondary battery including a cylindrical battery case configured to receive an electrode assembly and an electrolytic solution, a cap assembly located on the open upper end of the cylindrical battery case, and a jelly-roll type electrode assembly configured to have a structure in which a positive electrode sheet and a negative electrode sheet are wound in the state in which a separator is interposed therebetween, wherein a protective layer, made of a material that exhibits high thermal conductivity, is formed on at least a portion of the inner surface of the cylindrical battery case, including a crimping part is provided.