CYLINDRICAL SECONDARY BATTERY COMPRISING IMPROVED CURRENT COLLECTOR PLATE, BATTERY PACK AND VEHICLE INCLUDING THE SAME

A cylindrical secondary battery includes an electrode assembly having a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode, the positive electrode, the negative electrode, and the separator being wound in a winding direction, the positive electrode including a positive electrode uncoated portion exposed beyond the separator, the negative electrode including a negative electrode uncoated portion exposed beyond the separator, a positive electrode current collector plate coupled to the positive electrode uncoated portion by one or more positive electrode welding portions, and a negative electrode current collector plate coupled to the negative electrode uncoated portion by one or more negative electrode welding portions. A coupling area between the positive electrode uncoated portion and the positive electrode current collector plate is smaller than a coupling area between the negative electrode uncoated portion and the negative electrode current collector plate.