Abstract: This application provides a positive electrode active material, a positive electrode plate, a secondary battery, a power consuming apparatus, and a preparation method. The positive electrode active material includes polycrystalline particles designated as the first active particles and monocrystalline or quasi-monocrystalline particles designated as second active particles. (Dv90?Dv10)/Dv50 of the first active particles and the second active particles are respectively designated as X1 and X2, where X1/X2 satisfies 0.2?X1/X2?0.7.

Abstract: The present disclosure relates to a secondary battery and a battery module. The secondary battery includes a case including a receiving space with an opening; a cap assembly connected to the case and close the opening; an electrode assembly disposed in the receiving space and including two end faces opposite to each other in a first direction perpendicular to an axial direction of the receiving space, and tabs extending from the end faces and two or more electrode units stacked in the axial direction; and a current collecting unit, including a first piece extending in the axial direction and a first current collecting piece connected to the first piece, the tab extends in the first direction and is connected to the first current collecting piece, and a portion of the tab connected to the first current collecting piece and the first current collecting piece are stacked in the axial direction.

Abstract: Provided are a silicon-carbon composite material and a preparation method therefor, a secondary battery, and an electric device. The silicon-carbon composite material includes a core and a coating coated on the surface of the core, the core includes a carbon matrix and a silicon-based material located on the surface of the carbon matrix; the silicon-based material includes a silicon cluster and a silicon carbide cluster, the silicon carbide cluster forms a network structure, and the silicon cluster is located in a gap of the network structure. The silicon-carbon composite material can eliminate the memory effect of silicon and improve the capacity retention rate.

Abstract: The composite silicon material includes an inner core and a silicon-containing cladding layer cladded on the outer side of the inner core. The inner core comprises a silicon-carbon material, the silicon-carbon material includes a porous conductive material and a first silicon-based material, the outer surface of the porous conductive material has pores, and at least a portion of the first silicon-based material is distributed in the pores. The silicon-containing cladding layer contains an ion-conducting material and a second silicon-based material. The second silicon-based material is dispersed in the ion-conducting material.

Abstract: A secondary battery comprises a positive electrode plate and a negative electrode plate. The negative electrode plate comprises a negative electrode active material layer. The negative electrode active material layer comprises a negative electrode active material. The negative electrode active material comprises a silicon-based material. In the same charging and discharging cycle process, the volume ratio of the negative electrode plate during charging and discharging of the secondary battery is R, wherein R is less than or equal to 1.5; and the volume ratio of the positive electrode plate during charging and discharging of the secondary battery is Y, wherein Y is less than or equal to 0.98.

Abstract: A negative electrode plate includes a current collector and a coating applied to at least one surface of the current collector, the coating comprising a negative electrode active material and a metal powder, wherein the electrode potential of the metal powder in the coating relative to lithium may be between 1.6 and 3.5 V, the negative electrode active material may be a silicon-based material, and relative to the total weight of the silicon-based material and the metal powder, the proportion by weight of the metal powder may be 5 to 20% and the proportion by weight of the silicon-based material may be 80 to 95%.

Abstract: This application provides a charging method and apparatus, a vehicle, and a computer-readable storage medium. The method includes: obtaining a current voltage of a target battery; determining a current capacity of the target battery based on the current voltage; determining a chargeable capacity of the target battery based on the current capacity; and obtaining a real-time voltage of the target battery where the target battery is charged with the chargeable capacity, where the real-time voltage is used for determining a charge cut-off voltage of the target battery in a next charging.

Abstract: A battery cell, a battery, and an electric device. The battery cell comprises: a casing, the casing comprising a first wall portion; a pressure relief mechanism, the pressure relief mechanism arranged on the first wall portion; and an electrode assembly, accommodated in the casing, the electrode assembly comprising at least one negative electrode sheet, the first wall portion facing the edge of the negative electrode sheet, an active material layer formed on at least one side of the negative electrode sheet, the active material layer comprising a first region and a second region which are arranged in a first direction, the second region closer to the first wall portion than the first region, the first direction being parallel to the thickness direction of the first wall portion, and in a full-charge state is less than the thickness of the second region at least by 5 ?m.

Abstract: A battery cell, a battery, and an electrical apparatus. The battery cell comprises: an electrode assembly; and a casing, the casing being used for accommodating the electrode assembly. The casing is provided with a scoring groove and a buffer groove, the scoring groove defining a predetermined pressure relief area which is opened when the battery cell is subjected to pressure relief, and the buffer groove being located on the side of the scoring groove away from the geometric center of the predetermined pressure relief area.

Abstract: A battery cell, a battery, and an electric device are disclosed. The battery cell includes a casing with a first wall, a pressure relief structure disposed on the first wall, and an electrode assembly accommodated in the casing. The electrode assembly comprises multiple electrode sheet layers stacked in a first direction, the layers including cathode and anode electrode sheet layers. Each electrode sheet layer includes an electrode sheet body, a first active material layer, and a second active material layer disposed on opposite sides of the sheet body. At least one electrode sheet layer is configured as a first preset electrode sheet layer, in which the distance between its first active material layer and the first wall is greater than the distance between its second active material layer and the first wall. The first direction is parallel to a plane of the first wall.

Abstract: A battery cell, a battery, and an electric device. The battery cell includes a case. A pressure relief mechanism is provided on a first wall portion. An electrode assembly is accommodated in the case and includes at least one negative electrode sheet with an active material layer on at least one side. In a second direction, the first wall portion faces an edge of the negative electrode sheet, and the minimum distance D between the pressure relief mechanism and the edge of the active material layer is 3 mm to 15 mm. Based on the total mass of the active material layer, the proportion S of active material is 0.5% to 25%. In a first direction, the minimum distance d between an edge of the pressure relief mechanism and an outer surface of the second or third wall portion is 3 mm to 20 mm.

Abstract: A negative electrode sheet, a secondary battery, and an electric device. The negative electrode sheet includes a negative electrode current collector, a buffer layer, and an active layer, where the buffer layer is located between the negative electrode current collector and the active layer; the buffer layer includes a first binder; and an active material of the active layer includes silicon-carbon composite particles, and the silicon-carbon composite particles include a porous carbon material and a silicon material located in pores of the porous carbon material.

Abstract: The composite silicon material includes an inner core and a silicon-containing cladding layer cladded on the outer side of the inner core. The inner core comprises a silicon-carbon material, the silicon-carbon material includes a porous conductive material and a first silicon-based material, the outer surface of the porous conductive material has pores, and at least a portion of the first silicon-based material is distributed in the pores. The silicon-containing cladding layer contains an ion-conducting material and a second silicon-based material. The second silicon-based material is dispersed in the ion-conducting material.

Abstract: The present application relates to a silicon-carbon composite material and a preparation method therefor, a negative electrode sheet, a secondary battery, and an electrical device. The silicon-carbon composite material comprises a porous carbon matrix and a silicon-based material layer located in pores of the porous carbon matrix, the silicon-based material layer comprises a sub-nano silicon cluster and a sub-nano silicon carbide cluster, and the surface of the sub-nano silicon carbide cluster is in contact with the surface of the sub-nano silicon cluster. The silicon-carbon composite material has small expansibility, good cycle performance and fast charging performance and high energy density.

Abstract: A silicon composite material and a preparation method therefor, a negative electrode sheet, a secondary battery, and an electrical apparatus. The silicon composite material comprises a one-dimensional conductive material, an inner core, and a coating layer, the outer surface of the inner core is coated with the coating layer, the one-dimensional conductive material is arranged on the outer surface of the coating layer, and the inner core comprises a silicon-based material. The silicon composite material has good cycle performance and fast charging performance.

Abstract: Provided are a battery charging method and device, and a storage medium that are applicable to a lithium-ion battery with an N/P range of 0.5 to 1.1. The method includes: obtaining, by a power management system, a state of health (SOH) loss of the lithium-ion battery; and determining a charge cut-off voltage of a next charge process based on the SOH loss, an initial charge cut-off voltage of the lithium-ion battery, and a voltage correction factor, where the initial charge cut-off voltage is determined based on the N/P, and the charge cut-off voltage increases with increase of a count of charging. The N/P range is 0.5 to 1.1, thereby reducing the dosage of the negative electrode and reducing cost. In addition, the charge cut-off voltage of the next charge process is increased based on the SOH loss, thereby ensuring that the lithium-ion battery is free from lithium plating.

Abstract: A silicon composite material and a preparation method, a negative electrode plate, a battery, and an electrical apparatus. The silicon composite material comprises a silicon-based material and a flexible material, wherein the hardness of the flexible material is less than the hardness of the silicon-based material. The silicon-based material comprises at least one of elemental silicon, a silicon-oxygen compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The flexible material is located on at least part of the surface of the silicon-based material. By means of the combination of the flexible material and the silicon-based material, the risk of a current collector being crushed during the preparation of an electrode plate can be reduced, and the compacted density of the electrode plate can be improved, thus increasing the energy density of a battery.

Abstract: A silicon composite material and a preparation method therefor, a negative electrode sheet, a secondary battery, and an electric device. The silicon composite material comprises a core and a first coating layer covering the surface of the core; the core comprises a first core and a second core; the first core comprises a first conductive material; the first conductive material comprises a flexible conductive material; the second core comprises a silicon-based material of which the surface is coated with a second coating layer; and the second coating layer contains a second conductive material. The silicon composite material has the characteristics of good cycle performance and fast charging performance.

Abstract: The present disclosure relates to a secondary battery and a battery module. The secondary battery includes a case including a receiving space with an opening; a cap assembly connected to the case and close the opening; an electrode assembly disposed in the receiving space and including two end faces opposite to each other in a first direction perpendicular to an axial direction of the receiving space, and tabs extending from the end faces and two or more electrode units stacked in the axial direction; and a current collecting unit, including a first piece extending in the axial direction and a first current collecting piece connected to the first piece, the tab extends in the first direction and is connected to the first current collecting piece, and a portion of the tab connected to the first current collecting piece and the first current collecting piece are stacked in the axial direction.

Abstract: The present application relates to a negative electrode active material and a preparation method therefor, a negative electrode sheet, a secondary battery, and an electric device. The negative electrode active material comprises expanded graphite, a porous carbon layer, and silicon particles; the expanded graphite comprises a plurality of graphite layers; the porous carbon layer is at least distributed on an interlayer surface of one graphite layer, and the silicon particles are at least distributed in pore channels of porous carbon of the porous carbon layer.