A cable-type secondary battery (100; 300) having a horizontal cross section and extending longitudinally, and comprising: a core (110; 310) for supplying lithium ions, which comprises an electrolyte; an inner electrode comprising an open-structured inner current collector (120; 320) surrounding the outer surface of the core (110; 310) for supplying lithium ions, an inner electrode active material layer (130; 330) surrounding the outer surface of the inner current collector (120; 320), a conductive material-coating layer (131; 331) formed on the outer surface of the inner electrode active material layer (130; 330) and comprising a conductive material and a first polymer binder, and a porous coating layer (132; 332) formed on the outer surface of the conductive material-coating layer (131; 331) comprising a second polymer binder and inorganic particles, wherein in the porous coating layer (132; 332) the inorganic particles are bound to each other by the second polymer binder in the state that the inorganic particles are filled in contact with each other, from which interstitial volumes are formed between the inorganic particles, and the interstitial volumes form pores of the porous coating layer (132; 332); and wherein the inorganic particles and the second polymer binder in the porous coating layer (132; 332) are present in a weight ratio of 10:90 to 95:5 a separation layer (140; 340) surrounding the outer surface of the inner electrode to prevent a short circuit between electrodes; and an outer electrode surrounding the outer surface of the separation layer (140; 340) and comprising an outer current collector (160; 360) and an outer electrode active material layer (150; 350). a core (110; 310) for supplying lithium ions, which comprises an electrolyte; an inner electrode comprising an open-structured inner current collector (120; 320) surrounding the outer surface of the core (110; 310) for supplying lithium ions, an inner electrode active material layer (130; 330) surrounding the outer surface of the inner current collector (120; 320), a conductive material-coating layer (131; 331) formed on the outer surface of the inner electrode active material layer (130; 330) and comprising a conductive material and a first polymer binder, and a porous coating layer (132; 332) formed on the outer surface of the conductive material-coating layer (131; 331) comprising a second polymer binder and inorganic particles, wherein in the porous coating layer (132; 332) the inorganic particles are bound to each other by the second polymer binder in the state that the inorganic particles are filled in contact with each other, from which interstitial volumes are formed between the inorganic particles, and the interstitial volumes form pores of the porous coating layer (132; 332); and wherein the inorganic particles and the second polymer binder in the porous coating layer (132; 332) are present in a weight ratio of 10:90 to 95:5 a separation layer (140; 340) surrounding the outer surface of the inner electrode to prevent a short circuit between electrodes; and an outer electrode surrounding the outer surface of the separation layer (140; 340) and comprising an outer current collector (160; 360) and an outer electrode active material layer (150; 350).