Abstract: An electrode assembly, a secondary battery, a battery pack, and an electrical apparatus. In the electrode assembly, there are several electrode plate portions sequentially arranged in a laminated manner along its own thickness direction. During structural design, the current collector in at least one of the electrode plate portions is configured as a barrier, and by controlling the ratio between the thermal conductivity ?0 of the barrier and the thickness d0 of the barrier to be less than 3×107 W/(K*m2), the heat flux density of the barrier along the thickness direction of the electrode assembly is reduced and the thermal resistance is increased, thus forming an effective thermal barrier in the thickness direction of the electrode assembly.

Abstract: A battery and an electrical device are provided. The battery includes at least one first battery cell and at least one second battery cell, an internal resistance of the first battery cell is greater than that of the second battery cell, and a heat transfer rate of the first battery cell is less than that of the second battery cell.

Abstract: An electrode assembly, a battery cell, a battery, and an electrical device are provided. The electrode assembly includes: a plurality of electrode plates, each of the plurality of electrode plates having a first side and a second side which are oppositely arranged along a first direction, and at least one of the first side and the second side being provided with a tab; and a separator, arranged alternately with a plurality of electrode plates. The separator is configured to be thermally insulated on at least one of the first side and the second side; and/or the separator is configured to be thermally insulated on an outermost layer of the plurality of electrode plates.

Abstract: The present application relates to a current collector, an electrode plate, a battery cell, a battery, and an electric device. The current collector includes a stainless steel current-collecting portion for collecting a current, where the stainless steel current-collecting portion includes a blank area and a coating area that are arranged adjacent to each other in a preset direction, the coating area is configured to be coated with an active material, and the blank area has a hardness less than that of the coating area.