Abstract: Provided are an electrode assembly, a battery cell, a battery, and an electrical device, belonging to the field of battery technology. The electrode assembly includes a cladding layer, a plurality of stacked electrode sheets, and a separator disposed between the two adjacent electrode sheets. The electrode sheet includes an active material region and an inactive material region, the active material regions of the plurality of electrode sheets and the separator are stacked to form a body portion, and the inactive material regions of the plurality of electrode sheets are stacked to form a tab portion protruding from the body portion. The cladding layer at least clads a circumference of the body portion to cover an edge of the active material region.

Abstract: A cell core, a battery cell, a battery, and an electric device are described. The cell core includes a cell core body, where the cell core body includes at least one electrode assembly, the cell core body has two opposite end faces and a cell core side face connected between the two end faces, and tabs of any one of the electrode assemblies are led out from at least one end face of the two end faces; where the cell core further includes a cell core protection layer, the cell core protection layer covers at least a part of a side face of the cell core body, and the cell core protection layer includes an inorganic coating layer or an organic-inorganic composite structure coating layer. Such cell core helps reduce a risk of short circuit between the cell core and a housing.

Abstract: A protection method for a secondary battery includes evacuating the secondary battery through an injection opening of the secondary battery to within 100 kPa, introducing a first reactant into the secondary battery through the injection opening until a pressure of the secondary battery rises by more than 1 Pa and maintaining the pressure for more than 1 ms, evacuating the secondary battery through the injection opening to within 100 kPa, and introducing a second reactant into the secondary battery through the injection opening until the pressure rises by more than 1 Pa and maintaining the pressure for more than 1 ms, thereby forming a protection layer on an internal surface of the secondary battery.

Abstract: Provided are an electrode plate and a secondary battery having the same. The electrode plate comprises a current collector and an active material layer, wherein the current collector comprises a main body portion and tabs, the active material layer is coated on the surface of the main body portion, and the tabs extend from one end of the main body portion along the first direction; a first insulating portion is formed on the end face of the main body portion that is provided with the tabs, and a second insulating portion different from the first insulating portion is formed on the end faces of the main body portion that are not provided with the tabs. The electrode plate of the present application has a good end-face insulation protection and can improve the safety performance of the secondary battery.

Abstract: The present application relates to a separator, including a porous substrate, and a coating on at least one surface of the porous substrate. The coating may include a first region and a second region, the first region including an inorganic ceramic particle and a first polymer, the second region including a second polymer, and the first region having a same thickness as the second region, where a weight content of the second polymer in the second region may be 20%-100%, based on a total weight of the second region.

Abstract: A secondary battery includes an electrode plate including a current collector, a functional layer, and an active material layer. At least a portion of a surface of the current collector includes a plurality of protruding portions and a plurality of recessed portions. The functional layer is disposed in one or more of the plurality of recessed portions. The active material layer covers and contacts the current collector and the functional layer. The functional layer includes at least one of a polymer material or a positive temperature coefficient (PTC) material.

Abstract: The disclosure relates to an end cover assembly, a secondary battery, a battery pack and an electric device. An end cover assembly for a secondary battery includes: an end cover; a first terminal including a first connecting section and a second connecting section disposed along a radial direction; a second terminal including a third connecting section, a fuse section and a fourth connecting section sequentially connected along the radial direction; along an axial direction, orthographic projections of the first and third connecting sections at least partially overlap with each other, one of the first and third connecting sections is configured to connect with a busbar, the other is configured to connect with an electrode assembly, the fourth connecting section is configured to connect with the second connecting section; and an insulating component, at least a part of which is located between the first connecting section and the third connecting section.

Abstract: The disclosure relates to an end cover assembly, a secondary battery, a battery pack and an electric device. An end cover assembly for a secondary battery includes: an end cover; a first terminal including a first connecting section and a second connecting section disposed along a radial direction; a second terminal including a third connecting section, a fuse section and a fourth connecting section sequentially connected along the radial direction; along an axial direction, orthographic projections of the first and third connecting sections at least partially overlap with each other, one of the first and third connecting sections is configured to connect with a busbar, the other is configured to connect with an electrode assembly, the fourth connecting section is configured to connect with the second connecting section; and an insulating component, at least a part of which is located between the first connecting section and the third connecting section.