Abstract: Disclosed is a method of manufacturing a polyurethane filter foam having excellent air permeability, elasticity, and restoring force. In the method of manufacturing the polyurethane filter foam, the cell size of the filter foam is made regular by controlling the pressure by adjusting the diameter of the foaming head of a foaming machine, rather than adding a cell opener, cell irregularity caused by poor dispersion of the cell opener is alleviated, and air permeability, porosity, and compression set are excellent.

Abstract: The present invention relates to a secondary battery capable of reducing costs and increasing capacity. For example, disclosed is a secondary battery characterized by comprising: an electrode assembly including a first electrode, a second electrode, and a separator; a case accommodating the electrode assembly; and a cap assembly coupled to the upper portion of the case, wherein the first electrode comprises: a first current collector; a first current collecting tab structure extending from the first current collector and having a plurality of bent current collection parts; and a first lead tab electrically connected to the first current collecting tab structure, wherein, in the first current collecting tab structure, the width of the current collection parts increases from the center of the electrode assembly to the outside, and the distance between the current collection parts increases.

Abstract: The present disclosure relates to a secondary battery, and provides a secondary battery capable of reducing heat generation and improving safety by reducing a welding area.

Abstract: An embodiment of the present invention relates to a cylindrical secondary battery comprising: a cylindrical can having a bottom surface and a side portion extending from the bottom surface, one end of the side portion being open to form an opening; an electrode assembly accommodated in the can; and a cap assembly including a gasket which is inserted into the can with the electrode assembly inserted in the can to come into contact with the electrode assembly, and a cap plate which is disposed on the gasket and is electrically connected to the electrode assembly, wherein the can has, at the edge of the opening, a curling portion which presses the gasket to bring the gasket into contact with the cap plate.

Abstract: A technical object to be solved according to the present disclosure is to provide a secondary battery which has reduced electrical resistance by directly connecting an electrode assembly to a can and/or a terminal without lead tabs and also has an increased battery capacity by removing lead tabs. To this end, the present disclosure provides a secondary battery comprising: a can; an electrode assembly accommodated in the can and including a first uncoated portion extending in a first direction and a second uncoated portion extending in a second direction opposite to the first direction; a first current collector plate electrically connected to the first uncoated portion of the electrode assembly; a first terminal portion coupled to the can and electrically connected to the first current collector plate; and a second terminal portion coupled to the can and electrically connected to the second uncoated portion of the electrode assembly.

Abstract: A cylindrical secondary battery including a can including a circular bottom part and a cylindrical side part having an opened one end, an electrode assembly in which a first electrode plate, a second electrode plate, and a separator are wound and which is accommodated in the can, and a collecting plate arranged in a direction toward the first electrode plate. The first electrode plate and the collecting plate, and the second electrode plate and the bottom part are electrically connected to each other in a non-welding manner. According to the embodiment, since the electrode assembly and the collecting plate and also the electrode assembly and the can are electrically connected to each other without the welding, the electrode assembly may be prevented or reduced from being damaged by foreign substances generated during the welding, thereby improving stability of the secondary battery.