Abstract: This application provides a negative electrode active material and a preparation method thereof. The negative electrode active material may be self-embedded graphite composed of graphite A and graphite B, where the surface of the graphite A may have a tenon structure, the surface of the graphite B may have a mortise structure, the tenon structure of the graphite A and the mortise structure of the graphite B may be mutually embedded, and a hydrogen bond may be formed between the tenon structure of the graphite A and the mortise structure of the graphite B.

Abstract: A carbon material includes an external region and an internal region disposed on the inside of the external region, the external region being a region formed by extending for a distance of 0.25 L from the surface of the particles of the carbon material towards the interior of the particles, L being a short-axis length of the particles of the carbon material; total pore area of the external region being denoted as S1 and total pore area of the internal region being denoted as S2, and S2>S1. The carbon material can make the secondary battery have high initial columbic efficiency, high energy density and good cycling performance. A method for preparing the carbon material, and a secondary battery and an electrical device comprising the carbon materials are also provided.

Abstract: A method for preparing a modified graphite includes performing crushing on coal-based needle coke to obtain a first material, performing shaping fine powder removal on the first material to obtain a second material, performing heat treatment on the second material in a reaction kettle and then cooling the second material after the heat treatment to room temperature to obtain a third material, and performing graphitization on the third material in a graphitization furnace and then cooling the third material after the graphitization to room temperature to obtain the modified graphite.

Abstract: The present application provides a carbon material, a method for preparing the same, and a secondary battery and an electrical device comprising the same. The carbon material includes a pore structure, wherein the carbon material has 3R and 2H phases and satisfies 0<I3R(101)/I2H(004)?0.100, in which I3R(101) is the diffraction peak intensity of 101 crystallographic plane of the 3R phase in the X-ray diffraction pattern of the carbon material, and I2H(004) is the diffraction peak intensity of 004 crystallographic plane of the 2H phase in the X-ray diffraction pattern of the carbon material. The carbon material provided in the present application can make the secondary battery have high initial columbic efficiency and also good cycling and dynamic performances.

Abstract: A battery includes a positive electrode plate, a negative electrode plate, and a separator. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer located on at least one side of the negative electrode current collector. The negative electrode active material layer includes a negative electrode active material. The negative electrode active material includes graphite. A quantity proportion of secondary particles in the negative electrode active material is greater than or equal to 65%; an oil absorption value of the negative electrode active material is 40 mL/100 g to 65 mL/100 g; and a particle size by volume Dv1 of the negative electrode active material is 4 ?m to 8 ?m.

Abstract: A secondary battery, a preparation method thereof, and a battery module, a battery pack, and an apparatus containing such secondary battery are provided. In some embodiments, the secondary battery includes a negative-electrode plate, where the negative-electrode plate includes a negative-electrode current collector and a negative-electrode film layer, the negative-electrode film layer includes a first negative-electrode film layer and a second negative-electrode film layer, and the second negative-electrode film layer is located between the negative-electrode current collector and the first negative-electrode film layer; and the first negative-electrode film layer includes a first negative-electrode active material, the first negative-electrode active material includes a first graphite, the first graphite is artificial graphite, and a distribution of volume-based particle size Dv99 of the first negative-electrode active material is ?23 ?m.

Abstract: A secondary battery and an electric apparatus are disclosed. The secondary battery includes a negative electrode plate including a negative electrode current collector and a negative electrode film layer with a thickness of H; a first surface away from the negative electrode current collector; and a second surface opposite the first surface. A first region of the negative electrode film layer includes a first active material with a thickness range from the second surface of the negative electrode film layer to 0.3H. The first active material comprises a first silicon-based material, which comprises secondary particles formed by aggregation of primary particles. A second region of the negative electrode film layer comprises a second active material with a thickness range from the first surface of the negative electrode film layer to 0.3H.

Abstract: A negative electrode plate includes a current collector and a film layer disposed on the current collector. The film layer includes a first portion and a second portion disposed along a thickness direction of the film layer, where the first portion is disposed on the current collector, and the second portion is disposed on the first portion. The first portion includes a first carbon-based active material, the second portion includes a second carbon-based active material, the second carbon-based active material includes secondary particles, and a powder compacted density of the first carbon-based active material is greater than a powder compacted density of the second carbon-based active material.

Abstract: This application discloses a negative-electrode active material and a preparation method thereof, a secondary battery, and a battery module, a battery pack, and an apparatus that include such secondary battery. The negative-electrode active material includes a core and a coating layer covering at least part of a surface of the core, where the core includes artificial graphite, the coating layer includes amorphous carbon, a volume-based particle size distribution of the negative-electrode active material satisfies Dv99?24 ?m, a volume-based median particle size Dv50 of the negative-electrode active material satisfies 8 ?m?Dv50?15 ?m, Dv99 is a particle size corresponding to a cumulative volume distribution percentage of the negative-electrode active material reaching 99%, and Dv50 is a particle size corresponding to a cumulative volume distribution percentage of the negative-electrode active material reaching 50%.

Abstract: The present application provides a secondary battery and an electrical device. The negative electrode plate includes a negative electrode current collector and a negative electrode film which has a first surface away from the negative electrode current collector and a second surface opposite to the first surface and has a thickness denoted as H; a region within a thickness ranging from the second surface of the negative electrode film to 0.3 H is denoted as a first region of the negative electrode film, a region within a thickness ranging from the first surface of the negative electrode film to 0.3 H is denoted as a second region of the negative electrode film; the first region includes a first active material including a first carbon-based material and having a pore structure, and the second region includes a second active material including a second carbon-based material.

Abstract: This application provides a carbon material, a preparation method thereof, and a secondary battery and electric apparatus containing the same. The carbon material includes a pore structure, and in a thermogravimetric analysis test of the carbon material under air atmosphere, a weight loss rate of the carbon material at 35° C. to 790° C. is less than or equal to 60%. The carbon material provided in this application enables the secondary battery to combine high initial coulombic efficiency and good storage performance.

Abstract: A secondary battery and an electric apparatus are disclosed. The secondary battery includes a negative electrode plate including a negative electrode current collector and a negative electrode film layer with a thickness of H; a first surface away from the negative electrode current collector; and a second surface opposite the first surface. A first region of the negative electrode film layer includes a first active material with a thickness range from the second surface of the negative electrode film layer to 0.3H. The first active material comprises a first silicon-based material, which comprises secondary particles formed by aggregation of primary particles. A second region of the negative electrode film layer comprises a second active material with a thickness range from the first surface of the negative electrode film layer to 0.3H.

Abstract: This application relates to a secondary battery, a process for preparing the same and an apparatus containing the secondary battery. In particular, the negative electrode plate comprises a negative current collector and a negative electrode film, wherein the negative electrode film comprises a first negative electrode film and a second negative electrode film, the first negative electrode film is comprises a first negative electrode active material, and the particle size uniformity of the first negative electrode active material is from 0.4 to 0.6; the second negative electrode film comprises a second negative electrode active material, and the particle size uniformity of the second negative electrode active material is from 0.25 to 0.45, and a ratio of the particle size uniformity of the first negative electrode active material to the particle size uniformity of the second negative electrode active material is from 1.05 to 1.9.

Abstract: This application discloses a secondary battery including a positive electrode plate and a negative electrode plate, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode film disposed on a surface of the positive electrode current collector and comprising a positive active material, the negative electrode plate comprises a negative electrode current collector and a negative electrode film disposed on a surface of the negative electrode current collector and comprising a negative active material. The positive active material comprises one or more of layered lithium transition metal oxides and modified compounds thereof, and a resistance R of the negative electrode plate satisfies: 6.0 m??R?12.0 m?; or the positive active material comprises one or more of lithium-containing phosphates with olivine structure and modified compounds thereof, and a resistance R of the negative electrode plate satisfies: 3.0 m??R?7.0 m?.

Abstract: The present application relates to a secondary battery, a process for preparing the same and an apparatus containing the same.

Abstract: This application discloses a secondary battery and an apparatus containing the secondary battery. The secondary battery secondary battery includes an electrode assembly including a cell and tabs extending from the cell, the cell includes a negative electrode plate, the negative electrode plate includes a negative current collector and a negative electrode film arranged on at least one surfaces of the negative current collector and including a negative active material, wherein the negative active material includes artificial graphite including secondary particles; and the cell satisfies 5 cm?0.5×?{square root over (a2+b2)}?15 cm, and a?15 cm, wherein a is the maximum size of the cell in the direction that the tabs extend, in cm; and b is the maximum size of the cell in a direction perpendicularly intersecting with the direction that the tabs extend, in cm.

Abstract: A secondary battery including a negative electrode plate including a negative electrode current collector and a negative electrode film formed on at least one surface of the negative electrode current collector is provided, wherein the negative electrode film has a first surface away from the negative electrode current collector and a second surface disposed opposite to the first surface, thickness of the negative electrode film being denoted as H, a region within a thickness ranging from the second surface of the negative electrode film to 0.3 H being denoted as first region of the negative electrode film, a region within a thickness ranging from the first surface of the negative electrode film to 0.3 H being denoted as second region of the negative electrode film.

Abstract: The present application provides a carbon material, a method for preparing the same, and a secondary battery and an electrical device comprising the same. The carbon material includes an external region and an internal region disposed on the inside of the external region, the external region being a region formed by extending for a distance of 0.25 L from the surface of the particles of the carbon material towards the interior of the particles, L being a short-axis length of the particles of the carbon material; total pore area of the external region being denoted as S1 and total pore area of the internal region being denoted as S2, and S2>S1. The carbon material provided in the present application can make the secondary battery have high initial columbic efficiency, high energy density and good cycling performance.

Abstract: The present application provides a carbon material, a method for preparing the same, and a secondary battery and an electrical device comprising the same. The carbon material includes a pore structure, an adsorption amount of linseed kernel oil to 100 g of the carbon material 100 g is denoted as A in ml, a specific surface area of the carbon material is denoted as B in m2/g and the carbon material satisfies: 36?A×B?75. The carbon material provided in the present application can make the secondary battery have high initial columbic efficiency, high energy density and good cycle performance and storage performance.

Abstract: The present application provides a carbon material, a method for preparing the same, and a secondary battery and an electrical device comprising the same. The carbon material includes a pore structure, wherein the carbon material satisfies 0.150?ID/IG?0.280, with ID indicating an intensity of the D peak of the Raman spectrum at 1350±50 cm?1 and IG indicating an intensity of the G peak of the Raman spectrum at 1580±50 cm?1. The carbon material provided in the present application can make the secondary battery have high initial columbic efficiency, high energy density, good cycling performance and storage performance.