Electrode for secondary battery with improved safety, manufacturing method thereof, and secondary battery including same electrode

A secondary battery, comprising:

• a positive electrode including:
• a positive current collector;
• and
• a positive electrode active material layer formed on one side or both sides of the current collector, and
• a negative electrode including:
• a negative current collector;
• and
• a negative electrode active material layer,
• wherein a first plurality of apertures having diameters between 500 μm and 5 mm that penetrate the positive current collector and the positive electrode active material layer are formed in a thickness direction,
• a second plurality of apertures having diameters between 500 μm and 5 mm that penetrate the negative current collector and the negative electrode active material layer are formed in a thickness direction,
• the first and second plurality of apertures have a lateral cross-section of one or more selected from a group consisting of circular, oval, and polygonal cross-sectional shapes,
• the positive electrode has an elongation of 0.3% to 1.0%, and the negative electrode has an elongation of 2.0 to 2.5%, the elongation being the arithmetic mean of the longitudinal elongation and the lateral elongation measured at a rate of 0.5 mm/min by universal testing machine equipment (UTM) equipment, and
• the first and second plurality of apertures are arranged in a pattern in which a unit pattern of their array is a rectangle or an equilateral triangle, and the unit pattern is repeatedly arranged, an aperture interval in a longitudinal direction of sides in the unit pattern being from 1 mm to 8 mm.