SUB PLATE ASSEMBLY AND SECONDARY BATTERY INCLUDING THE SAME

A secondary battery includes an electrode assembly, a case in which the electrode assembly is accommodated, the case having one opening, a sub plate assembly that includes a sub plate coupled to the electrode assembly and a current collector coupled to the sub plate, and a cap assembly that is connected to the sub plate assembly and is coupled to the one opening of the case. The current collector includes a lower current collector and an upper current collector protruding above the lower current collector, and the upper current collector penetrates the sub plate to couple the current collector and the sub plate.