Cable-type secondary battery

A cable-type secondary battery having a horizontal cross section of a predetermined shape and extending longitudinally, comprising:

• an inner electrode having two or more first electrodes arranged in parallel to each other, each first electrode comprising an inner current collector extended in the longitudinal direction, and an inner electrode active material layer formed on the surface of the inner current collector;
• a separation layer surrounding the outer surface of the inner electrodes to prevent a short circuit between electrodes;
• and
• an outer electrode surrounding the outer surface of the separation layer and having an outer electrode active material layer and an open-structured outer current collector.