Abstract: An electrochemical device includes a negative electrode sheet. The negative electrode sheet includes a current collector, a first coating layer, and a second coating layer. The first coating layer is located between the current collector and the second coating layer. The second coating layer includes a negative active material. The first coating layer includes a conductive carbon material. The conductive carbon material includes at least one of carbon nanotubes or graphene. Based on a mass of the first coating layer, a mass percent of the conductive carbon material is 20% to 60%. The main material of the first coating layer is at least one of carbon nanotubes or graphene.

Abstract: A lithium transition metal composite oxide, comprising a twin crystal structure. The twin crystal structure includes a first crystalline region and a second crystalline region. A grain boundary exists between the first crystalline region and the second crystalline region. The first crystalline region includes a first region located within 20 nm from the grain boundary. The second crystalline region includes a second region located within 20 nm from the grain boundary. An angle between a transition metal layer in the first region and a transition metal layer in the second region is 65° to 80°. By adjusting the angle between the transition metal layer in the first region and the transition metal layer in the second region to fall within 65° to 80°, it can improve stability of the twin crystal structure, and in turn, improve the cycle performance of the electrochemical device at a high voltage.

Abstract: An electrochemical apparatus includes an electrode assembly and a conductive plate. The electrode assembly is of a wound structure and includes a first electrode plate including a first conductive layer and a first conductive material layer. The first conductive layer includes a first surface and a second surface. The first conductive material layer is provided on the first surface. The first surface includes a first region. The conductive plate is connected to the first region and extends out of the first electrode plate. The conductive plate includes a third region and a fourth region connected to each other. The third region includes a connection region. The conductive plate is connected to the first region through the connection region. The third region includes a first side, a second side, a third side, and a fourth side. The first region includes a fifth side, a sixth side, and a seventh side.

Abstract: A winding-type lithium ion battery includes an electrode assembly; the electrode assembly includes a first electrode plate, a separator, and a second electrode plate that are successively stacked and wound; the first electrode plate includes a first current collector and multiple first tabs electrically connected to the first current collector; the second electrode plate includes a second current collector and multiple second tabs electrically connected to the second current collector; the electrode assembly is flat, and a notch S is provided at least one corner of the electrode assembly.

Abstract: A battery includes a battery cell and a casing assembly for receiving the battery cell. The battery cell includes a first electrode tab. The battery further includes an insulating member and a conductive member, the insulating member is connected between the casing assembly and the conductive member. The casing assembly defines a first through hole, and the insulating member defines a second through hole connected to the first through hole. The first electrode tab is electrically connected to the conductive member. A power consuming device including the battery is further provided. The conductive member of the present disclosure substitutes for the terminal post of existing art, increasing the energy density of the battery.

Abstract: Provided are a rolling apparatus and a processing device, which are used for rolling an electrode plate. The rolling apparatus includes a first roller and a second roller, where the first roller and the second roller are disposed at two sides of the electrode plate in a thickness direction of the electrode plate. The first roller is provided with a plurality of recessed portions, the electrode plate includes a plurality of insulation coating layer regions and a plurality of tabs, and in a projection of the electrode plate in the thickness direction, at least part of a projection of the insulation coating layer region and a projection of the tab are located within a projection of the recessed portion. The rollers deflect under a large rolling pressure.

Abstract: A negative active material includes a carbon material. The carbon material satisfies the following relationship: 6<Gr/K<16, Gr is a graphitization degree of the carbon material, measured by X-ray diffraction; and K is a ratio Id/Ig of a peak intensity Id of the carbon material at a wavenumber of 1250 cm?1 to 1650 cm?1 to a peak intensity Ig of the carbon material at a wavenumber of 1500 cm?1 to 1650 cm?1, and is measured by using Raman spectroscopy, and K is 0.06 to 0.15.

Abstract: An electrochemical device, including a positive electrode, a negative electrode, a separator and an electrolyte. The electrolyte includes a nitrile compound, and the mass percentage of the nitrile compound in the electrolyte is A %; the negative electrode includes a current collector, wherein the current collector comprises a first region and a second region; the first region is provided with a negative electrode active substance layer; the second region does not comprise a negative electrode active substance layer; the area of the second region is B % of the surface area of the current collector; and A×B<600.

Abstract: A management method of an electrochemical device, includes: when the electrochemical device is in a preset state, measuring a predetermined parameter of the electrochemical device, and in response to the predetermined parameter meeting a preset condition, performing at least one discharge-charge operation on the electrochemical device. The discharge-charge operation includes: discharging the electrochemical device to a second voltage threshold, and charging the electrochemical device to a third voltage threshold. The second voltage threshold is less than a first voltage threshold, the first voltage threshold is a limited charge voltage of the electrochemical device, and a difference between the third voltage threshold and the first voltage threshold is not greater than 20%.

Abstract: An electrode assembly and a lithium ion electric roll having the same are provided. The electrode assembly includes: a first electrode unit; a first anti-puncture cushion; in which the first electrode unit includes a first electrode sheet, an second electrode sheet, and a separator, the second electrode sheet comprises a second top edge and a second bottom edge along the length direction of the first electrode unit; an edge of the first anti-puncture cushion exceeds the second electrode sheet from the second top edge or the second bottom edge along the length direction of the first electrode unit.

Abstract: A control method and device of a voltage converter and a voltage control system are provided. In some embodiments, the control device includes a first control module configured to obtain a current reference value according to an output voltage of a voltage converter and a given voltage value; a current modulation module configured to reduce the current reference value when an output current of a voltage converter is greater than a first current threshold; and a second control module configured to control the output current of a voltage converter according to the reduced current reference value and an output current.

Abstract: A negative electrode active material includes graphite and amorphous carbon, where according to Raman testing, the negative electrode active material satisfies: 1.6?WD/WG?2.6, where WD is a peak width at half height of peak D within 1340 cm?1 to 1370 cm?1 in the Raman spectrum, 40 cm?1?WD?100 cm?1, and WG is a peak width at half height of peak G within 1570 cm?1 to 1590 cm?1, 15 cm?1?WG?50 cm?1. The negative electrode active material undergoes surface treatment, where the surface thereof has a higher surface lattice defect degree, effectively improving a gram capacity and kinetics performance thereof, thereby making the electrochemical apparatus including the negative electrode active material have both high energy density and good electrochemical performance.

Abstract: An electrochemical apparatus includes a housing and an electrode assembly accommodated in the housing. The electrode assembly includes a first electrode plate, a second electrode plate, and a separator wound together. The first electrode plate includes a first current collector having a first region and a second region; and a first active material layer disposed in the first region. The second region is provided at an end of the first current collector in a first direction to form a first tab. The second electrode plate includes a second current collector; at least two second tabs; and a second active material layer disposed on the second current collector. The at least two second tabs are connected to an end of the second current collector, the at least two second tabs being facing away from the second region in a first direction; the at least two second tabs are spaced apart in a winding direction of the electrode assembly and are integrally formed with the second current collector.

Abstract: An electrochemical device includes a cathode, an anode, a separator and a binding layer. The separator is disposed between the cathode and the anode, and at least one binding layer is included between the cathode and the anode. The binding layer includes a high molecular polymer. A dielectric constant of the high molecular polymer is 5 F/m to 50 F/m. By optimizing the dielectric constant of the high molecular polymer in the binding layer of the electrochemical device, a binding force of the binding layer can be effectively increased, deformation of the anode or the cathode due to volume swelling during charge and discharge cycles is reduced, and peeling from the separator is avoided.

Abstract: A battery cell includes a first electrode assembly, a second electrode assembly and a housing. In a thickness direction of the battery cell, the first electrode assembly includes a first surface and a second surface opposite to the first surface, the second electrode assembly includes a third surface and a fourth surface opposite to the third surface. A housing includes an accommodation cavity configured to accommodate the first electrode assembly and the second electrode assembly, the accommodation cavity includes a bottom wall, and the first surface and the third surface are both opposite to the bottom wall. The battery cell further includes: a first adhesive layer, including a first bonding side and a second bonding side. The first bonding side is bonded to both the second surface and the fourth surface, and the second bonding side is bonded to the housing.

Abstract: A composite material includes a graphite particle. A surface of the graphite particle is provided with a first region and a second region. The first region is made of graphite, and the second region includes a hard carbon layer. A surface area of the first region is denoted as A1 ?m2, and a surface area of the second region is denoted as A2 ?m2, 0?A1/A2?9. A thickness of the hard carbon layer is H nm, 5?H?500. By controlling the coating amount and coating area of the hard carbon to satisfy the above relationship, this application can improve energy density, capacity performance, and the like at the same time of enhancing dynamic performance.

Abstract: A negative electrode including a negative electrode active material layer and an additive. The additive includes a metal sulfide. The additive is distributed in the negative electrode active material layer, and/or distributed on the surface of the negative electrode active material layer. The negative electrode effectively improves the performance of the lithium ion battery, and greatly improves the capacity and cycle performance of the lithium ion battery.

Abstract: This application discloses a bidirectional vent valve, a battery, and an electrical device. The bidirectional vent valve includes: a valve seat, where the valve seat is configured to form a gas duct, and the gas duct includes a first end and a second end; a bidirectional valve assembly, where the bidirectional valve assembly is movably disposed in the gas duct, and is configured to open or close the gas duct through movement relative to the gas duct; and a first elastic component, configured to exert a force on the bidirectional valve assembly to close the air duct, and, when an air pressure difference between the first end and the second end of the gas duct is greater than a first threshold, the bidirectional valve assembly is configured to overcome the force of the first elastic component to open the gas duct.

Abstract: An electrolyte includes ethyl propionate, propyl propionate, ethylene carbonate, and propylene carbonate, where based on a total mass of the electrolyte, a mass percentage of ethyl propionate is a %, a mass percentage of propyl propionate is b %, a mass percentage of ethylene carbonate is c %, and a mass percentage of propylene carbonate is d %, where 20?a+b?50, 0<c/d<1, and 15?c+d?50. The electrolyte significantly improves floating charge performance of electrochemical apparatuses at high voltage.

Abstract: A back roller includes a roller body and a wear-resistant layer. The roller body has an axis and a roll surface disposed around the axis. The wear-resistant layer covers the roll surface. Vickers hardness (H) of the wear-resistant layer is 800 HV?H?1400 HV. The roll surface is covered by the wear-resistant layer, and the Vickers hardness (H) of the wear-resistant layer is controlled to be between 800 HV and 1400 HV, so that the roll surface is effectively protected, and wear resistance of the roll surface is improved. In this way, the wear-resistant layer is in direct contact with a material during operation, thereby effectively reducing an abrasion loss on the roll surface and extending the service life of the roll surface.