Abstract: An electrode piece, a preparation method thereof, a battery and an electric apparatus are provided. The electrode piece includes a current collector and an active layer arranged on a surface of the current collector; the active layer is provided with a first groove and a second groove, and a groove bottom of the second groove is higher than that of the first groove, and is lower than a surface of the active layer that faces away from the current collector; and the electrode piece has a first side edge and a second side edge that are arranged opposite each other along a first direction, and one side edge of the groove bottom of the second groove is flush with at least one of the first side edge and the second side edge and is located on at least one side of the first groove along the first direction.

Abstract: The present disclosure provides a wound-type cell and a preparation method thereof, a battery, and an electronic product. The wound-type cell includes a positive sheet, a negative sheet, and an insulated separator located between the positive sheet and the negative sheet; the negative sheet includes a negative base layer, a negative coating, and a negative tab set on the surface of the negative base layer. The negative coating covers surface of the negative base layer, and the negative coating has a tab connection area that avoids the negative tab. The negative tab is located in the tab connection area; the insulated separator between the tab connection area and the positive sheet is provided with a barrier layer covering the tab connection area. The provided solutions are helpful to reduce safety risks caused by lithium-plating during the fast charging of lithium ion battery.

Abstract: The application discloses a lithium-ion cell, a battery and a power device, which belongs to the technical field of lithium-ion battery structure. A side surface of an end portion of a cell body of the lithium-ion cell has a thin area relative to a middle portion of the cell body, and the lithium-ion cell further includes adhesive paper attached to the thin area. In this application, a special adhesive paper is designed and attached to the thin area formed due to thinning processing at the edge of the end portion of the lithium-ion cell body, and is suitable for compensating for the thin area of the lithium-ion cell, so that the cell has a flat surface, is stressed uniformly during hot-pressing formation and has a good bonding.

Abstract: The present disclosure provides a wound-type cell and a preparation method thereof, a battery, and an electronic product. The wound-type cell includes a positive sheet, a negative sheet, and an insulated separator located between the positive sheet and the negative sheet; the negative sheet includes a negative base layer, a negative coating, and a negative tab set on the surface of the negative base layer. The negative coating covers surface of the negative base layer, and the negative coating has a tab connection area that avoids the negative tab. The negative tab is located in the tab connection area; the insulated separator between the tab connection area and the positive sheet is provided with a barrier layer covering the tab connection area. The provided solutions are helpful to reduce safety risks caused by lithium-plating during the fast charging of lithium ion battery.