Secondary Battery and Method for Manufacturing the Same

Abstract

The secondary battery includes: a can member having an opening; a top cap assembly sealing the opening; a gasket insulating the opening from the top cap assembly; and a hot melt applied to a surface of the gasket, wherein the hot melt has fluidity and viscosity at a predetermined temperature or more and is hardened at a temperature less than the predetermined temperature.

1 . A secondary battery comprising:
 a can member having an opening;   a top cap assembly disposed within the opening;   a gasket insulating the opening from the top cap assembly and providing a seal between the can member and the top cap assembly; and   a hot melt applied to a surface of the gasket and configured to adhere the gasket to at least one of: the can member or the top cap assembly,   wherein the hot melt has fluidity and viscosity at a first temperature equal to or greater than a predetermined temperature and is in a hardened state at a second temperature less than the predetermined temperature.   
     
     
         2 . The secondary battery of  claim 1 , wherein the predetermined temperature is a glass transition temperature (Tg) of a material of the hot melt. 
     
     
         3 . The secondary battery of  claim 1 , wherein the predetermined temperature is 60° C. 
     
     
         4 . The secondary battery of  claim 1 , wherein the hot melt has an adhesive property at the first temperature. 
     
     
         5 . The secondary battery of  claim 1 , wherein the hot melt comprises a material that is configured to repeatedly transition between a viscous state and the hardened state, the material being in the viscous state at the first temperature and being in the hardened state at the second temperature. 
     
     
         6 . The secondary battery of  claim 1 , wherein the hot melt comprises a thermoplastic resin and a tackifier. 
     
     
         7 . The secondary battery of  claim 6 , wherein the hot melt further comprises a coupling agent. 
     
     
         8 . The secondary battery of  claim 6 , wherein the thermoplastic resin comprises a polyester-based resin. 
     
     
         9 . The secondary battery of  claim 6 , wherein the tackifier comprises at least one or more of a phenol-based resin, a carbon-based resin, and a rosin-based resin. 
     
     
         10 . The secondary battery of  claim 6 , wherein the coupling agent comprises one or more of aminosilane and vinylsilane. 
     
     
         11 . A method for manufacturing a secondary battery, the method comprising:
 a preparation step of preparing a can member, a top cap assembly, and a gasket;   a coating step of applying a hot melt that is dissolved in an organic solvent to a surface of the gasket;   a drying step of drying the gasket to evaporate the organic solvent after the coating step;   an assembly step of assembling the cap member and the top cap assembly with the gasket after the drying step to manufacture the secondary battery; and   an activation step of activating the secondary battery,   wherein the activation step comprises changing a phase of the hot melt by changing a temperature of the secondary battery, such that the gasket is airtightly adhered to the can member and the top cap assembly by the hot melt that is changed in phase.   
     
     
         12 . The method of  claim 11 , wherein the activation step comprises:
 a room-temperature aging process of aging the secondary battery at a room temperature;   a high-temperature aging process of aging the secondary battery at a first temperature of 60° C. or more that is higher than the room temperature; and   a charging/discharging process of charging and discharging the secondary battery at a second temperature of 60° C. or less that is lower than the first temperature, after the high-temperature aging process.   
     
     
         13 . The method of  claim 12 , wherein the hot melt is in a hardened state during the room-temperature aging process, the hot melt is changed in phase to a viscous state in which the hot melt has fluidity and viscosity during the high-temperature aging process, and the hot melt is again changed in phase to the hardened state at the room temperature. 
     
     
         14 . The method of  claim 11 , wherein the organic solvent comprises at least one or more of toluene, xylene, and methyl ethyl ketone. 
     
     
         15 . The secondary battery of  claim 7 , wherein the thermoplastic resin comprises a polyester-based resin. 
     
     
         16 . The secondary battery of  claim 7 , wherein the tackifier comprises at least one or more of a phenol-based resin, a carbon-based resin, and a rosin-based resin.