Abstract: A secondary battery includes a positive electrode plate. that includes a positive current collector, a first positive active material layer distributed on one side of the positive current collector, and a second positive active material layer distributed on an other side of the positive current collector and a negative electrode plate that includes a negative current collector, a first negative active material layer distributed on one side of the negative current collector and opposite to the second positive active material layer, and a second negative active material layer distributed on an other side of the negative current collector. A resistance of the first positive active material layer is R1, a resistance of the second positive active material layer is R2, a resistance of the first negative active material layer is R3, a resistance of the second negative active material layer is R4.

Abstract: A battery module, a battery pack, and an electric apparatus are provided. In some embodiments, the battery module includes a first type of cell and a second type of cell that are cells of different chemical systems, where the first type of cell includes n first cells, the second type of cell includes m second cells, n and m each are selected from an integer greater than 1, at least one of the first cells and at least one of the second cells are electrically connected in series, and the first cell and the second cell satisfy at least the following relationships: 0.08??RB/?RA?3.50, and 0.10 m?/100 cycles??RA?0.40 m?/100 cycles, where ?RA is a discharge resistance growth rate of the first cell, and ?RB is a discharge resistance growth rate of the second cell; and IMPB<IMPA, where IMPA is an alternating current impedance of the first cell, and IMPB is an alternating current impedance of the second cell.

Abstract: A positive electrode sheet includes a current collector including a coating region and a non-coating region, a resistance layer disposed on the current collector and including a conductive agent, a first binder, and a first positive electrode active material, and a positive electrode active material layer including a second positive electrode active material, a conductive agent, and a second binder. A resistance of the resistance layer is greater than a resistance of the positive electrode active material layer. In a cross section of the positive electrode sheet, a projection of at least a part of the positive electrode active material layer on the current collector and a projection of the resistance layer on the current collector do not overlap. A polarization parameter P of the positive electrode sheet is in a range of 0.4-65.0 and equals ((1?S)/S)·(R1/R2).

Abstract: A battery cooling device includes a shell, a cooling channel arranged inside the shell and configured to allow flowing of cooling fluids and restrict flowing directions of the cooling fluids along the cooling channels, a cooling fluid flow regulation component arranged inside the shell and configured to be deformed from a first opening degree to a second opening degree when the temperature rises where the fluid flow at the first opening degree is less than the fluid flow at the second opening degree, and a regulation component deformation restriction component arranged inside the shell and configured to be deformed from a first configuration to a second configuration when the temperature rises.

Abstract: A secondary battery includes a positive electrode plate. that includes a positive current collector, a first positive active material layer distributed on one side of the positive current collector, and a second positive active material layer distributed on an other side of the positive current collector and a negative electrode plate that includes a negative current collector, a first negative active material layer distributed on one side of the negative current collector and opposite to the second positive active material layer, and a second negative active material layer distributed on an other side of the negative current collector. A resistance of the first positive active material layer is R1, a resistance of the second positive active material layer is R2, a resistance of the first negative active material layer is R3, a resistance of the second negative active material layer is R4.

Abstract: The present application provides a battery pack and a power consuming device powered by the battery pack. The battery pack includes a battery pack cavity and a plurality of battery cells received in the battery pack cavity. An interior space of the battery pack cavity can be divided into a first region with a temperature change rate of K1 and a second region with a temperature change rate of K2, where 0.066?K1?0.131 and 0.034?K2?0.066, K1 and K2 being expressed in ° C./min. The plurality of battery cells include at least one first battery cell arranged in the first region, and at least one second battery cell arranged in the second region. The battery pack of the present application can reduce or avoid the cask effect at low temperature and improve the energy retention rate at low temperature.

Abstract: A control method of a battery apparatus includes acquiring a state parameter of a first battery module of the battery apparatus, controlling the first battery module and a charging device to form a first charging loop in response to the state parameter of the first battery module being less than a preset threshold, and controlling the first battery module, a second battery module of the battery apparatus, and the charging device to be connected in series to form a second charging loop in response to the state parameter of the first battery module being greater than or equal to the preset threshold. A charging rate of the first charging loop is higher than a charging rate of the second charging loop.

Abstract: A positive electrode sheet includes a current collector, a resistance layer disposed on the current collector, and a positive electrode active material layer. The current collector includes a coating region and a non-coating region. The resistance layer includes a conductive agent and a first binder. The positive electrode active material layer includes a positive electrode active material, a conductive agent, and a second binder. A resistance of the resistance layer is greater than a resistance of the positive electrode active material layer. In a cross section of the positive electrode sheet, a projection of a part of the positive electrode active material layer on the current collector overlaps with a projection of the resistance layer on the current collector, and a projection of another part of the positive electrode active material layer on the current collector does not overlap with the projection of the resistance layer on the current collector.

Abstract: A positive electrode sheet includes a current collector including a coating region and a non-coating region, a resistance layer disposed on the current collector and including a conductive agent, a first binder, and a first positive electrode active material, and a positive electrode active material layer including a second positive electrode active material, a conductive agent, and a second binder. A resistance of the resistance layer is greater than a resistance of the positive electrode active material layer. In a cross section of the positive electrode sheet, a projection of at least a part of the positive electrode active material layer on the current collector and a projection of the resistance layer on the current collector do not overlap. A polarization parameter P of the positive electrode sheet is in a range of 0.4-65.0 and equals ((1?S)/S)·(R1/R2).

Abstract: The present application provides a battery pack and a power consuming device powered by the battery pack. The battery pack includes a battery pack cavity and a plurality of battery cells received in the battery pack cavity. An interior space of the battery pack cavity can be divided into a first region with a temperature change rate of K1 and a second region with a temperature change rate of K2, where 0.066?K1?0.131 and 0.034?K2?0.066, K1 and K2 being expressed in ° C./min. The plurality of battery cells include at least one first battery cell arranged in the first region, and at least one second battery cell arranged in the second region. The battery pack of the present application can reduce or avoid the cask effect at low temperature and improve the energy retention rate at low temperature.