A secondary battery is disclosed. In one aspect, the secondary battery includes an electrode assembly having a top space, a first main surface and a second main surface opposing each other. The secondary battery also includes an electrode tab extending outwardly from the top surface of the electrode assembly so as to channel heat away from the electrode assembly. The secondary battery further includes a fixing member formed adjacent to the electrode tab and covering at least the top surface of the electrode assembly so as to reduce a thermal deformation of the electrode assembly caused by the heat from the electrode tab.