The present invention relates to a battery cell. The battery cell comprises: an electrode assembly provided with an electrode tab; a case which accommodates the electrode assembly and of which at least a portion of an edge is sealed to provide a sealing surface; an electrode lead coupled to the electrode tab and led out of the case; a lead film disposed on each of top and bottom surfaces of the lead electrode disposed on the sealing surface of the case and coupled together with the sealing surface; and a main gas discharge tube disposed in the case and having one end buried in the lead film.

A battery module includes a heat-shrinkable tube serving as a module housing. The battery module includes a cell assembly having a plurality of pouch-type secondary batteries; a bus bar assembly having a bus bar frame and a bus bar mounted to an outer surface of the bus bar frame; and a heat-shrinkable tube formed to be shrunk by heat and configured so that the cell assembly is located therein, the heat-shrinkable tube being provided to surround a side surface of the cell assembly and a portion of the bus bar assembly.

A battery module includes a heat-shrinkable tube serving as a module housing. The battery module includes a cell assembly having a plurality of pouch-type secondary batteries; a bus bar assembly having a bus bar frame and a bus bar mounted to an outer surface of the bus bar frame; and a heat-shrinkable tube formed to be shrunk by heat and configured so that the cell assembly is located therein, the heat-shrinkable tube being provided to surround a side surface of the cell assembly and a portion of the bus bar assembly.

An embodiment of the present invention relates to a pouch-type secondary battery. According to embodiment of the present invention, the pouch-type secondary battery includes: an case configured to house an electrode assembly from which electrode tab are drawn out; sealing parts formed by adhering the case along outer peripheries of the electrode assembly; and folding parts formed by folding the sealing parts of surfaces on which the electrode tab drawn to an outside of the case is not formed, wherein a length of the folding part has a relationship with a thickness of the electrode assembly as the following equation: H≤T/2 (wherein, H is the height of the folded folding part, T is the thickness of the electrode assembly, based on a cross-section perpendicular to a direction in which the electrode tabs of the electrode assembly are drawn out).

An embodiment of the present invention relates to a pouch-type secondary battery. According to embodiment of the present invention, the pouch-type secondary battery includes: an case configured to house an electrode assembly from which electrode tab are drawn out; sealing parts formed by adhering the case along outer peripheries of the electrode assembly; and folding parts formed by folding the sealing parts of surfaces on which the electrode tab drawn to an outside of the case is not formed, wherein a length of the folding part has a relationship with a thickness of the electrode assembly as the following equation: H≤T/2 (wherein, H is the height of the folded folding part, T is the thickness of the electrode assembly, based on a cross-section perpendicular to a direction in which the electrode tabs of the electrode assembly are drawn out).

The present invention relates to a button-type secondary battery including: a lower can serving as a first electrode terminal; an upper can coupled to surround the lower can and serving as a second electrode terminal; and a gasket provided between the lower can and the upper can, wherein a recessed lower insertion groove and a recessed upper insertion groove are formed in a surface of the lower can and a surface of the upper can, which are in close contact with the gasket, respectively, the lower insertion groove and the upper insertion groove are spaced apart from each other so as not to face each other, and a sealing protrusion having a closed curve shape and being in close contact with the lower can and the upper can to increase in sealing force is formed on the gasket.

In order to create an electrochemical cell, comprising a housing, an electrochemical element arranged in an interior of the housing, and at least one cell terminal that comprises a terminal feed-through, which extends through a through-opening of the housing, which electrochemical cell is of simple construction and requires a low production expenditure but still reliably limits the short circuit current that arises in the case of a non-regular operating state, it is proposed that the electrochemical cell comprises an electrically conductive sealing element, which seals the through-opening of the housing and electrically conductively connects the cell terminal to the housing.

A battery pack leakage detection system and detection method are provided. The system includes a test container, a gas filling subsystem, a gas stirring subsystem and a test analysis subsystem. The method can test the sealing performance of the battery pack under the atmospheric pressure, so that the battery pack can meet the corresponding sealing grade requirements of IP67 and IP68. The method not only solves the problem that the traditional gas detection method cannot meet the test requirements of IP67 and IP68 due to insufficient measurement precision, but also solves the problem that the traditional vacuum helium detection method will damage the battery cells in the battery pack.

A secondary battery includes: a cylindrical case; an electrode assembly accommodated in the cylindrical case and including a positive electrode and a negative electrode; and a cap assembly sealing the cylindrical case. The cap assembly includes: a cap-up electrically connected to the positive electrode; a terminal plate coupled to an upper portion of the cap-up and electrically connected to the negative electrode; and a first insulating gasket between the cap-up and the terminal plate.

A secondary battery includes: a cylindrical case; an electrode assembly accommodated in the cylindrical case and including a positive electrode and a negative electrode; and a cap assembly sealing the cylindrical case. The cap assembly includes: a cap-up electrically connected to the positive electrode; a terminal plate coupled to an upper portion of the cap-up and electrically connected to the negative electrode; and a first insulating gasket between the cap-up and the terminal plate.