Abstract: A button-type secondary battery includes a lower can having a bottom surface; an upper can having a top, the upper can and the lower can being coupled to define a space therein; an electrolyte in the space; an electrode assembly in the space and including a negative electrode, a separator, and a positive electrode wound together; a gasket between the upper can and the lower can to electrically insulate the upper and lower cans; a top insulator that is electrically insulating and covering a top surface of the electrode assembly; and a bottom insulator that is electrically insulating and covering a bottom surface of the electrode assembly. The top and bottom insulators are each configured to expand in volume by absorbing the electrolyte. Surfaces of at least one of the top insulator and the bottom insulator are coated with a protective layer to prevent thermal shrinkage from occurring.

Abstract: A button type secondary battery includes a wound electrode assembly; a lower can with the electrode assembly and an electrolyte in the lower can; a top plate to close the lower can; a positive electrode terminal coupled to the top plate through a gasket to be electrically insulated from the top plate with a portion of the positive electrode terminal passing through a hole in the top plate to be bonded to a positive electrode tab; a top insulator covering a top surface of the electrode assembly; and a bottom insulator covering a bottom surface of the electrode assembly. The top insulator and the bottom insulator are each configured to expand in volume by absorbing the electrolyte. Surfaces of at least one or more of the top insulator and the bottom insulator are coated with a protective layer configured to prevent thermal shrinkage from occurring.

Abstract: Disclosed is a steel-concrete composite beam. The steel-concrete composite beam has an asymmetric I-section steel member having an upper flange, a lower flange and a web. The web is formed with at least one opening at a predetermined interval. The upper flange has a narrower width than the lower flange. A pair of C-section steel members is attached integrally to the lower flange of the asymmetric I-section steel form a first space filled with concrete. The concrete interlocks with the lower flange. A deck is supported on the C-section steel members. At least one transverse reinforcing bar of slab is arranged through the opening perpendicular to the asymmetric I-section steel. An upper concrete slab is poured with the concrete to be formed at a predetermined thickness. The concrete fills in a second space defined by the C-section steel members and the lower flange so that the upper flange of the asymmetric I-section steel is embedded.