Abstract: A secondary battery includes a first electrode sheet including a plurality of first conductive layers and a plurality of first bending portions and a second electrode sheet including a plurality of second conductive layers and a plurality of second bending portions. Two adjacent first conductive layers are connected through one of the first bending portions, and two adjacent second conductive layers are connected through one of the second bending portions. The plurality of first conductive layers and the plurality of second conductive layers are alternately stacked. Viewed along the first direction perpendicular to a surface of the first conductive layer, each first bending portion includes a first edge extending along a second direction perpendicular to the first direction; and each second bending portion includes a second edge extending along a third direction perpendicular to the first direction. The second direction is different from the third direction.

Abstract: An electrochemical device includes an electrode assembly and an electrolyte. The electrode assembly includes a negative electrode plate including a negative electrode active material layer. The negative electrode active material layer includes a negative electrode active material; and a negative electrode binder including an ester substance and a non-ester substance. Based on a mass of the negative electrode binder, a mass percentage of the ester substance is x; the electrolyte includes fluoroethylene carbonate and a high-kinetic solvent, the high-kinetic solvent includes at least one of ethyl propionate, propyl propionate, or diethyl carbonate. A ratio of a mass percentage of fluoroethylene carbonate to a mass percentage of the high-kinetic solvent in the electrolyte is y; and 17%?x+y?53%, y is from 0.4% to 14%. Based on a mass of the electrolyte, a mass percentage of fluoroethylene carbonate is from 0.1% to 10%.

Abstract: A secondary battery includes a housing, an electrode assembly disposed in the housing, and a first conductive plate. The electrode assembly is a stacked structure. The electrode assembly includes a first electrode plate, a separator, and a second electrode plate that are stacked sequentially in a first direction. The first conductive plate is connected to the first electrode plate. The first conductive plate extends out of the housing along a second direction perpendicular to the first direction. The first electrode plate includes a first outer electrode plate located at an outermost layer of the electrode assembly. When viewed in a third direction perpendicular to both the first direction and the second direction, the first outer electrode plate includes a first region and a second region connected in the second direction. When viewed in the third direction, the first region includes a first end connected to the second region.

Abstract: An electrochemical apparatus includes a housing, an electrode assembly, a first insulating layer, and an electrolyte, where the electrode assembly and the electrolyte are accommodated in the housing. The electrode assembly includes a plurality of electrode plates stacked along a first direction and a first separator disposed between the plurality of electrode plates. The electrode assembly further includes a first surface and a second surface opposite each other in the first direction, and a first end face connecting the first surface and the second surface. The first insulating layer is adhered to the first surface, the second surface, and the first end face. The first separator includes a substrate layer and a plurality of first coatings spaced apart on a surface of the substrate layer facing an adjacent electrode plate.

Abstract: A secondary battery includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The separator includes a substrate layer and a first adhesive layer. The substrate layer includes a third surface and a fourth surface opposite to each other. The third surface faces the negative electrode plate. The first adhesive layer is disposed on the third surface and is of a striped structure. A part of the separator extending beyond the negative electrode plate is defined as a separator extension part. The first adhesive layer is at least partially located on the separator extension part. A peel strength between the separator and the first negative electrode material layer is a N/m, and a peel strength between the first negative electrode material layer and the negative electrode current collector is b N/m, where 6.0?a?15.0, and a<b.

Abstract: The invention provides a unidirectional electromagnetic wave stealth device and a manufacturing method thereof. The device includes a first photonic crystal doped with a lossy dopant, a second photonic crystal containing an object to be cloaked and a first photonic crystal doped with a gain dopant, which are sequentially arranged. The first photonic crystal exhibits Dirac-like cone dispersion, the second photonic crystal has a photonic band gap, and a Dirac-like point frequency of the first photonic crystal is the same as a band-edge frequency of the photonic band gap of the second photonic crystal. The lossy dopant and the gain dopant are such that relative permittivities of the lossy dopant and the gain dopant are complex conjugates, and relative permeabilities of the lossy dopant and the gain dopant are 1. The stealth effect of the device is unidirectional, and the frequency of the cloaking electromagnetic wave is tunable.

Abstract: An electrode assembly includes a first electrode plate with a first current collector, a first conductive material layer provided with a first opening, and a second conductive material layer provided with a second opening. The first current collector includes a first surface and a second surface. The first surface includes a first region. The second surface includes a second region. When viewed from the first direction, the first region overlaps with the second region, and the first conductive plate is connected to the first region or the second region. The first opening includes first to third opening edges. The second opening includes fourth to sixth opening edges. The first, second, and third distances are the distances between the first-fourth, second-fifth, and third-sixth opening edges, respectively, the electrochemical device satisfies at least one of the following conditions: 0.2 mm?first distance; 0.2 mm?second distance; or 0.2 mm?third distance.

Abstract: A secondary battery includes a housing, a first tab, and an electrode assembly. The electrode assembly includes a first electrode plate. The first electrode plate includes a first current collector, a first active material layer disposed on a first surface of the first current collector and a second active material layer disposed on a second surface of the first current collector. The first active material layer is provided with a first groove exposing a first region of the current collector. A second region of the first current collector is covered with a second active material layer. The first region is opposite to the second region in a second direction. The first tab includes a first connecting portion, a first bent portion, and a second connecting portion that are connected in sequence.

Abstract: An electrode assembly includes a positive electrode plate. The positive electrode plate features a single-sided groove embedded tab structure. The positive electrode plate includes a positive electrode current collector and a second positive electrode active material layer disposed on a second surface of the positive electrode current collector. The second positive electrode active material layer includes a second positive electrode active material, where the second positive electrode active material includes element M, and the element M includes at least one of manganese, iron, lanthanum, zirconium, or yttrium. The positive electrode plate of this application can enhance energy density of the electrochemical apparatus based on the existing embedded tab structure.

Abstract: An electrochemical apparatus, including an electrode assembly. The electrode assembly includes a negative electrode plate and a positive electrode plate. The negative electrode plate includes a first negative electrode active material layer, a negative electrode current collector, a second negative electrode active material layer, and a first layer. The positive electrode plate includes a first positive electrode active material layer, a positive electrode current collector, and a second positive electrode active material layer. The negative electrode plate includes a first negative electrode winding layer and a second negative electrode winding layer. A negative electrode single-coated region of the negative electrode current collector is located on at least the first negative electrode winding layer and the second negative electrode winding layer.

Abstract: A method for determining injection mass of electrolyte for a battery includes: determining a total volume V1 of pores in a positive electrode active material layer, a negative electrode active material layer, and a separator of the battery; determining a volume V2 of electrolyte required by the negative electrode active material layer to ensure battery cycles; determining a volume V3 of electrolyte consumed by the battery in a formation process; determining a volume V4 of electrolyte consumed by the battery in an injection process; and determining the injection mass of electrolyte for the battery: MEl=(V1+V2+V3+V4)×?El. The injection mass of electrolyte for the battery is closer to actual optimal injection mass, which improves the accuracy of the electrolyte injection process, provides better electrochemical performance of the battery, and lowers the research and development costs of the battery.

Abstract: An electrochemical device includes a first electrode plate and a first conductive plate. The first electrode plate includes a first current collector and a first conductive material layer. The first conductive material layer is disposed on a first surface of the first current collector. The first conductive material layer is provided with a first opening, where a first region of the first surface exposed at the first opening. The first conductive plate is connected to the first region. The first electrode plate includes a first end edge, and the first end edge is provided with a first recess. When viewed from a first direction, the first recess is spaced apart from the first region. The first conductive plate covers a part of the first region, a part of the first conductive material layer, and a part of the first recess.

Abstract: A button cell includes an electrode assembly, a first electrode tab, and a housing provided with an accommodating cavity. The housing includes a first wall, a first end of the first electrode tab is connected to the electrode assembly, and a second end of the first electrode tab is connected to the first wall. The housing is provided with a groove including at least two continuously connected curves. Viewed from a direction perpendicular to the first wall, a projection of the first electrode tab on the first wall is a first projection, at least a portion of the at least two continuously connected curves is located outside the first projection, and a quantity of intersection points between a contour of the first projection and the at least two continuously connected curves is less than or equal to 2.

Abstract: A button cell includes an electrode assembly, a first housing, and a second housing, where the first housing and the second housing are connected and mated to form an accommodating space. The electrode assembly is disposed in the accommodating space. The first housing includes a first bottom wall and a first side wall connected to the first bottom wall. The first bottom wall is provided with a groove. A size of the first bottom wall in a first direction is T ?m, and a size of the groove in the first direction is H ?m, where 0.1T?H?0.7T and the first direction is perpendicular to the first bottom wall.

Abstract: A battery includes an electrode assembly, a first housing, a second housing, and a first adhesive layer. The first housing is connected to the second housing. The first adhesive layer is located between the first housing and the second housing, the first adhesive layer includes a first section, a second section, and a third section, a boundary point between the first section and the second section is at a position from the bottom of the first adhesive layer to a distance of H/4 from a second end surface of the battery, and a boundary point between the second section and the third section is at a position at which an end of the second housing close to the first end surface is located. Thickness of the first section, thickness of the second section, and thickness of the third section are all different.

Abstract: An electrochemical device includes an electrode assembly. The electrode assembly is formed by winding a stacking body. The stacking body includes a first electrode plate, a second electrode plate and a separator film. The first electrode plate includes a first conductive layer, a first conductive material layer and a first layer. The first conductive layer includes a first surface and a second surface arranged oppositely in a third direction, wherein the first surface includes a first region and a second region arranged sequentially in a first direction. The first conductive material layer is disposed in the first region. The second region is exposed from the first conductive material layer. The first conductive material layer includes a first conductive material region and a first edge region, the first conductive material region and the first edge region are arranged sequentially along a second direction.

Abstract: A battery includes an electrode assembly, a first housing, and a second housing. The first housing includes a first bottom wall and a first peripheral wall. The second housing includes a second bottom wall and a second peripheral wall. The first peripheral wall is arranged outside the second peripheral wall in a sleeving manner. Here, the second peripheral wall includes a first annular segment and a second annular segment, the second annular segment is located on one side of the first annular segment back away from the second bottom wall, the first annular segment is spaced apart from the first peripheral wall with a spacing of T1, the second annular segment is spaced apart from the first peripheral wall with a spacing of T2, and 30%?T2/T1?95%.

Abstract: An electrode assembly includes a first conductive portion, a second conductive portion and a first metal portion. The first conductive portion includes a first region provided with a conductive material layer and a second region separated from the first region; the first metal portion is welded with the second region, and the first metal portion has a third region where a weld mark is formed; when being observed in a first direction perpendicular to a first surface of the first conductive portion, the second region has a first end and a second end; the third region has a third end and a fourth end; the first metal portion has a fifth end in a second direction, and a sixth end disposed on an opposite side of the fifth end in the second direction and closer to the second end than the fifth end.

Abstract: An hard shell battery includes a housing, an electrode assembly, a first gasket, a second gasket, a conductive member, and a fastening member. The first gasket is disposed on an outer surface of the housing, and the second gasket is disposed on an inner surface of the housing. The conductive member is electrically connected to the electrode assembly, a shaft portion of the conductive member extends through a through hole in the housing into an accommodating cavity of the housing. A restraint portion of the conductive member abuts on a side of the first gasket facing away from the accommodating cavity. The fastening member is disposed on a side of the second gasket facing away from the first gasket, and in interference fit with the shaft portion via a mounting hole. The conductive member and the fastening member jointly press against the second gasket.

Abstract: An electrochemical apparatus including a housing, an electrode assembly, and a first conductive plate. The electrode assembly is disposed in the housing. The conductive plate is electrically connected to the electrode assembly and extends out from the housing. The electrochemical apparatus further includes a first layer, where an extending direction of the conductive plate is a first direction, and in the first direction, the first layer includes a first region and a second region connected to each other, the first region being disposed inside the housing, and the second region being disposed outside the housing. A direction perpendicular to a surface of the conductive plate is a second direction, and viewed along the second direction, the second region partially overlaps the conductive plate. The second region includes a first protrusion and a second protrusion. In a third direction, the first protrusion is separated from the second protrusion.