A secondary battery comprising: a case (no); an electrode assembly in the case; an electrolyte solution in the case; and an insulating tape (130, 140) disposed between the case and the electrode assembly, the insulating tape comprising first and second layers (141, 142), wherein the first layer comprises an insulating and non-adhesive material and the second layer is more reactive to the electrolyte solution than the first layer, and wherein the insulating tape comprises: a first tape wrapped around the bottom end of the electrode assembly, wherein the first tape extends no more than one third of the way up the electrode, and a second tape arranged along a termination line at which the winding of the electrode assembly ends to prevent the electrode assembly from being unwound, wherein a first gap exists between a first end of the second tape and the top of the electrode assembly and a second gap exists between a second end of the second tape and an uppermost edge of the first tape, wherein the first layer of the first tape surrounds a bottom surface of the electrode assembly and a side surface of the electrode assembly adjacent to the bottom surface simultaneously, wherein the second layer of the first tape is in direct contact with an inner bottom surface of the case and an inner side surface of the case adjacent to the inner bottom surface simultaneously, and wherein the second layer comprises a material that is arranged to react with the electrolyte solution to fix the electrode assembly to an inner surface of the case. a case (no); an electrode assembly in the case; an electrolyte solution in the case; and an insulating tape (130, 140) disposed between the case and the electrode assembly, the insulating tape comprising first and second layers (141, 142), wherein the first layer comprises an insulating and non-adhesive material and the second layer is more reactive to the electrolyte solution than the first layer, and wherein the insulating tape comprises: a first tape wrapped around the bottom end of the electrode assembly, wherein the first tape extends no more than one third of the way up the electrode, and a second tape arranged along a termination line at which the winding of the electrode assembly ends to prevent the electrode assembly from being unwound, wherein a first gap exists between a first end of the second tape and the top of the electrode assembly and a second gap exists between a second end of the second tape and an uppermost edge of the first tape, wherein the first layer of the first tape surrounds a bottom surface of the electrode assembly and a side surface of the electrode assembly adjacent to the bottom surface simultaneously, wherein the second layer of the first tape is in direct contact with an inner bottom surface of the case and an inner side surface of the case adjacent to the inner bottom surface simultaneously, and wherein the second layer comprises a material that is arranged to react with the electrolyte solution to fix the electrode assembly to an inner surface of the case. a first tape wrapped around the bottom end of the electrode assembly, wherein the first tape extends no more than one third of the way up the electrode, and a second tape arranged along a termination line at which the winding of the electrode assembly ends to prevent the electrode assembly from being unwound, wherein a first gap exists between a first end of the second tape and the top of the electrode assembly and a second gap exists between a second end of the second tape and an uppermost edge of the first tape, wherein the first layer of the first tape surrounds a bottom surface of the electrode assembly and a side surface of the electrode assembly adjacent to the bottom surface simultaneously, wherein the second layer of the first tape is in direct contact with an inner bottom surface of the case and an inner side surface of the case adjacent to the inner bottom surface simultaneously, and wherein the second layer comprises a material that is arranged to react with the electrolyte solution to fix the electrode assembly to an inner surface of the case.