Provided is a cable-shaped alkali metal battery comprising: (a) a first electrode comprising an electrically conductive porous rod having pores and a first mixture of a first electrode active material and a first electrolyte, wherein the first mixture resides in the pores of the porous rod; (b) a porous separator wrapping around the first electrode; (c) a second electrode comprising an electrically conductive porous layer wrapping around or encasing the porous separator, wherein the conductive porous layer contains pores and a second mixture of a second electrode active material and a second electrolyte, and the second mixture resides in the pores of the porous layer; and (d) a protective casing or packing tube wrapping around or encasing the second electrode.