A secondary battery includes: an electrode assembly including a first electrode plate from which a first current collecting tab protrudes, a second electrode plate from which a second current collecting tab protrudes, and a separator between the first electrode plate and the second electrode plate; a case accommodating the electrode assembly; and a current collector plate electrically connected to the first current collecting tab and including protrusions, and the first current collecting tab is vertically coupled to the current collector plate and includes coupling grooves to which the protrusions are coupled.