This positive electrode active substance for a non-aqueous electrolyte secondary battery contains a lithium-transition metal composite oxide which has a crystal structure belonging to the space group Fm-3m and is represented by the compositional formula Li.sub.xMn.sub.yM.sub.aO.sub.bF.sub.c (in the formula: M is at least one type of metal element excluding Mn; x+y+a=b+c=2; 1<x≤1.35; 0.4≤y≤0.9; 0≤a≤0.2; and 1.3≤b≤1.8). In addition, the lattice constant a of the lithium-transition metal composite oxide is 4.09-4.16.

A battery cell includes an electrode assembly, a housing configured to accommodate the electrode assembly and having an opening, an end cover configured to close the opening of the housing, and a current collecting member configured to electrically couple the electrode assembly to the end cover. The current collecting member is at least partly located between the electrode assembly and the end cover and abuts against the electrode assembly. The current collecting member has a hole. The electrode assembly is partly accommodated in the hole and contact a hole wall of the hole.

A battery cell includes an electrode assembly, a housing configured to accommodate the electrode assembly and having an opening, an end cover configured to close the opening of the housing, and a current collecting member configured to electrically couple the electrode assembly to the end cover. The current collecting member is at least partly located between the electrode assembly and the end cover and abuts against the electrode assembly. The current collecting member has a hole. The electrode assembly is partly accommodated in the hole and contact a hole wall of the hole.

A battery cell may comprise: an electrode assembly, a housing and an end cap. The electrode assembly may have a first tab. The housing may have an opening for accommodating the electrode assembly. The end cap may be configured to connect with the housing and cover the opening. The end cap may have an abutting surface and a welding groove, the abutting surface may be configured to abut against the first tab, and the welding groove may be recessed from one side of the end cap away from the electrode assembly towards the abutting surface. The end cap may form a connector between the abutting surface and the bottom surface of the welding groove, and the connector is configured for being welded with the first tab. The end cap is provided with a reinforcing structure, and the reinforcing structure is protruded from the bottom surface.

A battery cell may comprise: an electrode assembly, a housing and an end cap. The electrode assembly may have a first tab. The housing may have an opening for accommodating the electrode assembly. The end cap may be configured to connect with the housing and cover the opening. The end cap may have an abutting surface and a welding groove, the abutting surface may be configured to abut against the first tab, and the welding groove may be recessed from one side of the end cap away from the electrode assembly towards the abutting surface. The end cap may form a connector between the abutting surface and the bottom surface of the welding groove, and the connector is configured for being welded with the first tab. The end cap is provided with a reinforcing structure, and the reinforcing structure is protruded from the bottom surface.

A secondary battery includes a battery element including a positive electrode, a negative electrode, and an electrolytic solution, a housing member configured to accommodate the battery element, and a safety valve mechanism attached to the housing member. The safety valve mechanism includes a valve member including an opening valve portion configured to be opened; and an opening member including a plurality of opening portions radially arranged in a region opposed to the opening valve portion from a center of the region as a base point, and a plurality of protrusion portions radially arranged in a region outside the plurality of opening portions from the center and the plurality of protrusion portions protrude toward the plurality of opening portions. A number of the opening portions and a number of the protrusion portions are equal to each other, and each of the plurality of opening portions and each of the plurality of protrusion portions are opposed to each other in a direction toward the center.

A cylindrical secondary battery configured to have a structure to which an adhesion unit, including an adhesive material, a conductive material, and a gas-generating material, is provided. The adhesion unit is configured to couple a cap assembly, which functions as a positive electrode terminal of the cylindrical secondary battery, and a positive electrode tab of a jelly-roll type electrode assembly to each other.

A cylindrical secondary battery configured to have a structure to which an adhesion unit, including an adhesive material, a conductive material, and a gas-generating material, is provided. The adhesion unit is configured to couple a cap assembly, which functions as a positive electrode terminal of the cylindrical secondary battery, and a positive electrode tab of a jelly-roll type electrode assembly to each other.

The present invention relates to a washer for a secondary battery including a film layer and an adhesive layer disposed on at least one surface of the film layer, wherein the adhesive layer includes an adhesive component and an indicator component, and the indicator component is fat-soluble, a secondary battery including the same, and a method for manufacturing the washer.

A battery header cap and an assembly method thereof are provided, and the battery header cap includes a battery, a battery header, an insulating sleeve, and a header cap. The battery includes a battery body and a battery case, and the battery case has a header groove near a case opening. The battery header is disposed at the case opening, and the insulating sleeve completely covers the metal surface of the battery header cap. The header cap includes an electrode plane and a sidewall, the electrode plane has a header cap opening to expose the metal electrode, the electrode plane is disposed on the insulating sleeve, the sidewall covers the end of the battery case, and the end of the sidewall is embedded into the header groove. The structure provides support and insulating protection for the header and also enhances the sealability of the case.