Electrode, secondary battery, and electrode manufacturing apparatus

A secondary battery comprising:

• an electrode assembly including a first electrode, a second electrode, and a separator located between the first electrode and the second electrode;
• a case accommodating the electrode assembly;
• and
• a lead tab that is electrically connected to the electrode assembly and exposed outside the case,
• wherein at least one of the first electrode or the second electrode includes:
• a composite substrate including a metal layer comprising a first metal layer and a second metal layer and an insulating layer located between the first metal layer and the second metal layer;
• and
• a substrate tab including a first metal and having one side bonded to one side of at least one surface of the composite substrate and an other side bonded to the lead tab, and
• the substrate tab includes a second metal different from the first metal on a surface of the substrate tab.

An electrode manufacturing apparatus comprising:

• a first transfer unit configured to transfer a composite substrate sheet, the composite substrate sheet including a metal layer comprising a first metal layer and a second metal layer, and an insulating layer located between the first metal layer and the second metal layer;
• a second transfer unit configured to transfer a substrate tab sheet including a first metal to at least one surface of the composite substrate;
• a third transfer unit configured to transfer a buffer sheet including a second metal onto the substrate tab sheet;
• and
• a pressing unit configured to press a stacked structure in which the composite substrate sheet, the substrate tab sheet, and the buffer sheet are stacked.