331 results about "Natural graphite" patented technology

The invention relates to a hydrogen storage pellet enabling the production of compact, modular, safe and energy-efficient hydrogen reservoirs. The pellet according to the invention comprises a peripheral ring (4) having an outer diameter of expanded natural graphite (ENG) of a determined height, surrounding a wafer of a metal hydride (5) in the form of compacted powder.

The invention relates to the technical field of flux-cored wires. The preparation method comprises the following steps: weighing the following raw materials in parts by weight: 4-6 parts of chromium carbide powder, 7-9 parts of molybdenum powder, 6-8 parts of nickel powder, 10-15 parts of niobium powder, 15-18 parts of tungsten carbide powder, 7-11 parts of a modified titanium carbide agent, 5-8 parts of a blending agent added based on boron and 2-4 parts of 30-mesh natural graphite; 1-2 parts of sodium fluosilicate; 1-2 parts of aluminum powder; and 70-75 parts of iron powder. The flux-cored wire can adapt to complex service environments of parts such as rollers and continuous casting crystallizers in the metallurgical industry, the service life of the parts subjected to surfacing repair is prolonged, the production efficiency of the parts subjected to surfacing repair is improved, the obtained flux-cored wire achieves balance of high-temperature performance, mechanical performance and low-temperature stability, and the comprehensive applicability of products is improved.

The invention provides natural graphite powder for a high-temperature gas cooled reactor nuclear fuel element and a preparation method of the natural graphite powder. The preparation method comprises the following steps: performing screening, crushing, shaping and grading treatment on graphite fine powder to obtain powder with the particle size of 25-35 microns; carrying out primary purification and secondary purification on the powder by using a mixed acid solution, heating the obtained chemically purified graphite powder in vacuum, carrying out high-temperature purification, introducing a mixed gas of argon and carbon tetrafluoride when the temperature reaches 1800 DEG C, and starting a circular reaction; then continuously carrying out gradient heating to 2000 DEG C, 2200 DEG C and 2400 DEG C, and respectively carrying out circular reaction at each temperature; then cooling to 300-400 DEG C, introducing mixed gas of oxygen and argon, and carrying out oxidation treatment; and finally, scattering and homogenizing to obtain a natural graphite powder finished product. The natural graphite powder provided by the invention realizes lower total impurity element content and total boron equivalent and higher specific surface area.

Disclosed is a negative electrode including a negative electrode active material layer, wherein the negative electrode active material layer includes a negative electrode active material and a conductive agent. The negative electrode active material includes carbon-based active material particles including natural graphite and an amorphous carbon-based material. The carbon-based active material particles have a specific surface area of 1.4 m2 / g to 2.3 m2 / g, and the conductive agent includes carbon nanotubes having an average length of 1 μm to 12 μm. A secondary battery including the negative electrode is also disclosed.

The invention belongs to the field of graphite materials, and particularly relates to nuclear-grade natural graphite, preparation of the nuclear-grade natural graphite and application of the nuclear-grade natural graphite to preparation of high-temperature gas cooled reactor fuel spherulis.The preparation method comprises the steps that a natural graphite raw material is subjected to first-stage heat preservation treatment at the temperature T1 in advance, and a first-stage material is obtained; grinding and grading the first-section material to obtain graphite powder A and graphite powder B; then shaping and grading the graphite powder A to obtain graphite powder C; mixing the graphite powder B and the graphite powder C to obtain graphite powder D; the graphite powder D is subjected to liquid phase treatment in acid liquor in advance, and graphite powder E is obtained; the graphite powder E is subjected to two-stage gas-solid treatment with gas control and pressure control, and the nuclear-grade natural graphite is prepared. According to the method, the purity of the graphite can be obviously optimized, and in addition, the loss of strength in the purification process can be avoided, so that the graphite which is more than 5N, ultralow in nuclear reaction degradation impurities, excellent in strength and capable of meeting the application requirements of a nuclear reaction device can be obtained.

The invention relates to a battery monomer, a battery device and a power utilization device. A negative electrode material layer of the battery monomer comprises a first negative electrode film layer and a second negative electrode film layer; the first negative electrode film layer is closer to the negative electrode current collector than the second negative electrode film layer; the first negative electrode film layer comprises a first negative electrode active material and a first conductive agent, the first negative electrode active material comprises natural graphite, and the first conductive agent comprises a single-walled carbon nanotube; the second negative electrode film layer comprises a second negative electrode active material and a second conductive agent, the second negative electrode active material comprises artificial graphite, and the second conductive agent comprises a multi-walled carbon nanotube. The battery monomer provided by the invention has good cycle stability.

The invention discloses a silane functionalized graphene oxide / waterborne polyurethane hydrophobic coating and preparation, and belongs to the technical field of paints.The silane functionalized graphene oxide / waterborne polyurethane hydrophobic coating is prepared by the steps that natural graphite powder serves as a raw material, and graphene oxide is prepared through a Hummer method; n-(beta-aminoethyl)-gamma-aminopropyl trimethoxy silane is grafted to the surface of the graphene oxide through a chemical reduction method, and GO-AATS composite filler is obtained; then, castor oil is used as a soft segment, isophorone diisocyanate is used as a hard segment, and a series of GO-AATS-WPU emulsions are prepared. According to the silane functionalized graphene oxide / waterborne polyurethane hydrophobic coating and preparation, chemical bonds are formed between graphene oxide and waterborne polyurethane, and the interfacial compatibility of graphene oxide and waterborne polyurethane is improved, so that the mechanical property, water resistance, corrosion resistance and thermal stability of the waterborne polyurethane coating are improved.

The invention relates to the technical field of lithium battery negative electrode materials, in particular to a lithium battery graphite negative electrode material and a preparation method thereof. The preparation method of the graphite negative electrode material comprises the following steps: taking natural graphite as a raw material, sucking the natural graphite into a jet mill through a high-pressure fan for crushing, shaping, spheroidizing, shaping and the like to obtain a pre-product graphite powder, modifying the graphite powder, and performing secondary crushing and spheroidizing; according to the graphite negative electrode material prepared through modification and secondary spheroidization, the mechanical strength and the wear resistance of the material are improved, secondary spheroidization is facilitated, the spheroidization degree of the material is good, volume expansion is inhibited, the conductivity and the structural stability can be improved, and the service life of the material is prolonged. The cycle service life in the battery is prolonged; and the electrochemical performance is improved.

The invention discloses fast charge graphite, a preparation method thereof and a lithium ion battery negative electrode material, and the preparation method comprises the following steps: carrying out acid leaching elution and alkali liquor neutralization on natural graphite fine powder to passivate the surface of the natural graphite fine powder; mixing the passivated graphite fine powder with boric acid and acetic acid, and then carrying out heating reaction to obtain modified graphite fine powder; mixing the modified graphite fine powder with a binder, and granulating to obtain secondary particles; after the secondary particles are subjected to graphitization treatment, the graphitized secondary particles are coated with a carbon source coating agent, and then carbonization treatment is conducted in the inert atmosphere; and carrying out vacuum impregnation on the carbonized secondary particles in a lithium source solution, and drying to obtain the lithium ion battery positive electrode material. The preparation method has the advantages that the interlayer spacing of the natural graphite can be expanded by modifying the natural graphite fine powder, and then the natural graphite is subjected to granulation, graphitization and carbon coating treatment and then is subjected to gradient coating, so that the prepared fast-charging graphite has more excellent dynamic performance.

The present disclosure provides a dry battery electrode comprising a. at least one active material; b. at least one conductive carbon; and c. at least one fluorinated binder; wherein the active material is selected from natural graphite, silicon, synthetic graphite, expanded graphite, or combinations thereof. The present disclosure further provides a lithium-ion battery comprising the dry battery electrode as disclosed herein. Furthermore, the present disclosure provides a process for preparing the electrode.

The application discloses a kind of negative active material and its application.A kind of negative active material, including carbon material and silicon-based material;The carbon material includes artificial graphite, natural graphite, soft carbon, hard carbon, mesophase carbon microsphere, at least one in graphene;The chemical formula of the silicon-based material is X a Si b Y c Wherein, X includes at least one of P, As, Se, B, Ga, Mg, Al, Zn, Li, Y includes at least one of O, C, a, b, c satisfy 0≤a≤8, 0≤c≤10, 1≤(a+b)≤10, 2≤(b+c)≤10.The application has the advantages of improving the energy density, rate performance and cycle performance of lithium battery.

The invention relates to a preparation method and application of modified micro-expansion spherical graphite, in particular to a preparation method and application of modified micro-expansion spherical graphite. In order to solve the problems of poor rate capability and poor cycle stability of a natural graphite negative electrode material, the surface-modified micro-expansion spherical graphite is obtained by performing oxidation modification treatment on spherical graphite by adopting an electrochemical oxidation technology. The interlayer spacing is enlarged, the diffusion resistance of lithium ions is reduced, and the rate capability is improved. An oxygen-containing functional group is introduced, so that a uniform and stable SEI film is formed, and the cycling stability is improved. The coated asphalt is used as a precursor, and the carbon-coated spherical graphite with a core-shell structure is obtained through a controllable carbonization technology. The carbon coating layer can effectively inhibit graphite stripping, pulverization and volume expansion, and the pore structure can improve the electrolyte compatibility and improve the cycle stability. The method is applied to the field of lithium ion battery negative electrode materials.

The present invention relates to an electrode for a secondary battery in which a first electrode material mixture layer including a first negative electrode active material, a first conductive agent, and a first binder is formed on a current collector, and a second electrode material mixture layer including a second negative electrode active material, a second conductive agent, and a second binder is formed on the first electrode material mixture layer, wherein the first negative electrode active material and the second negative electrode active material each include at least one selected from the group consisting of natural graphite and artificial graphite, and when the electrode is analyzed by a shear strength analysis method, a ratio of a maximum value (σmax) to a minimum value (σmin) in a simplified shear strength (σ) profile is 1.7 or less.

The present invention discloses a negative electrode material, a negative electrode sheet and a secondary battery, relating to the technical field of secondary batteries. The negative electrode material includes natural graphite and amorphous carbon filled in the pores of the natural graphite; the particle hardness of the negative electrode material is 0.28 GPa to 0.4 GPa, and the elastic modulus is 7.0 GPa to 8.0 GPa; when the compaction density of the tablet of the negative electrode material is 1.5 to 2.0 g / cm<supgt;3< / supgt;, the orientation OI value of the tablet of the negative electrode material is y, and 4 < y ≤ 11. Applying this negative electrode material to a secondary battery can significantly improve the first Coulomb efficiency and cycle stability.

A secondary battery and an electric device. The secondary battery comprises a negative electrode sheet; the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer; the negative electrode film layer has a first surface away from the negative electrode current collector and a second surface arranged opposite to the first surface; the thickness of the negative electrode film layer is recorded as H; a region extending from the second surface to a thickness of 0.3 H of the negative electrode film layer is recorded as a first region of the negative electrode film layer, the first region comprises a first negative electrode active material, and the first negative electrode active material comprises a first carbon-based material; a region extending from the first surface to a thickness of 0.3 H of the negative electrode film layer is recorded as a second region of the negative electrode film layer, the second region comprises a second negative electrode active material, and the second negative electrode active material comprises a second carbon-based material; the first carbon-based material comprises natural graphite; and a total hole area S2 of an internal region of the second carbon-based material is greater than a total hole area S1 of an external region of the second carbon-based material.

The invention relates to the technical field of graphite purification, and discloses a method for high-temperature purification of natural graphite by using light metal halide salt, which comprises the following steps: mixing a natural graphite raw material with composite light metal halide salt according to a mass ratio of 1: 0.1-0.3, the composite light metal halide salt comprising a mixture of chloride salt and fluoride salt; the method comprises the following steps: in a first stage, heating to 800-1000 DEG C under the protection of inert gas, and keeping the temperature for 1-2 hours; in the second stage, the atmosphere is switched into a reducing gas atmosphere, the temperature is increased to 1200-1400 DEG C, and heat preservation is conducted for 3-5 h; in the third stage, the temperature is raised to 1800-2000 DEG C by utilizing halogen gas generated by halogen salt pyrolysis, and heat preservation is carried out for 0.5-1 h; and performing acid pickling, water washing and vacuum drying on the pyrolysis product to obtain graphite. Compared with a traditional high-temperature purification method, the highest pyrolysis temperature is reduced by 500-800 DEG C, the energy consumption is reduced by 40-60%, the production cost is greatly reduced, and the economical efficiency and sustainability of the process are improved.

One aspect of the present invention provides a precursor for a negative electrode material of a lithium secondary battery, the negative electrode material prepared from the precursor, and a method for preparing the same, the precursor for the negative electrode material having high capacity characteristics, excellent processability, and excellent lifespan characteristics by a structure in which natural graphite fine powder is distributed in high-hardness artificial graphite.

The present application relates to the technical field of secondary batteries. Disclosed are a negative electrode material, a negative electrode sheet and a secondary battery. The negative electrode material comprises natural graphite and amorphous carbon filled into pores of the natural graphite. The particle hardness of the negative electrode material is 0.28-0.4 GPa, and the elastic modulus thereof is 7.0-8.0 GPa. When the compaction density of a tablet of the negative electrode material is 1.5 g / cm3 to 2.0 g / cm3, the orientation OI value of the tablet of the negative electrode material is y, and 4<y≤11. When the negative electrode material is applied to a secondary battery, the initial coulombic efficiency and the cycling stability can be significantly improved.

A method of preparing a negative electrode which includes preparing a negative electrode structure including expanded natural graphite, impregnating the negative electrode structure with a pre-lithiation solution to form an impregnated negative electrode structure, and pre-lithiating the impregnated negative electrode structure by electrochemically charging the impregnated negative electrode structure to 10% to 20% of charge capacity of the negative electrode structure.

The present application relates to the technical field of solid lubricant, and particularly relates to a lubricant particle, which comprises a solid lubricant and a binder, the solid lubricant comprises natural graphite, molybdenum disulfide, hexagonal boron nitride and silicon dioxide; the mass content of the natural graphite is 5% to 20% based on the total mass of the solid lubricant, the mass content of the molybdenum disulfide is 5% to 20%, the mass content of the hexagonal boron nitride is 5% to 20%, and the mass content of the silicon dioxide is 40% to 85%. The lubricant particle of the present application can replace the existing powder solid lubricant to solve the problem that the powder solid lubricant is added into the metal binder, is dispersed and distributed in the carcass, hinders the combination of metal elements, and the lubricants are connected and bridged, further hindering the combination of metal elements.

The present invention relates to a negative electrode active material, a negative electrode for a lithium secondary battery, including same, and a lithium secondary battery. The negative electrode active material includes a silicon-based active material; and graphite, wherein the graphite includes natural graphite and artificial graphite, an absolute value of a ratio of a difference in average particle diameter (D50) size of the natural graphite with respect to the artificial graphite is 10% or less, and an absolute value of a ratio of a difference in average particle diameter (D50) size of the silicon-based active material with respect to the artificial graphite is 40% or less.

The application provides a high-rate long-cycle natural graphite-based composite negative electrode material and a preparation method and application thereof. The natural graphite-based composite negative electrode material has the characteristics of high-rate performance, low volume expansion performance and long-cycle performance. Firstly, submicron flake graphite particles are granulated into particles with a pore structure in a form of spray granulation; then, heat treatment is performed under a protective atmosphere to convert pitch into amorphous carbon; then, chemical vapor deposition technology is adopted to uniformly distribute nano titanium in the pore structure between the submicron flake graphite inside the spherical graphite particles and on the surface of the spherical graphite particles; subsequently, the nano titanium is converted into titanium nitride through nitriding treatment, that is, titanium nitride is deposited in the pore structure between the submicron flake graphite inside the spherical graphite particles and on the surface of the spherical graphite particles, to prepare the natural graphite-based composite negative electrode material.

The invention relates to a carbon graphite sealing material and a preparation method thereof, and belongs to the technical field of mechanical sealing materials, the sealing material comprises the following components: natural graphite powder and phenolic resin powder, and the mass part ratio of the natural graphite powder to the phenolic resin powder is 1: (0.2-0.4). The hardness of the material is not lower than 70 HSD, and the volume density of the carbon-graphite sealing material is not lower than 1.70 g / cm < 3 >. The sealing material is tested on a pump, and the abrasion loss does not exceed 0.1 mu m after 200 hours. The preparation method of the material comprises the following steps: fully mixing natural graphite powder and phenolic resin powder in a V-shaped mixer, and kneading the obtained mixed powder in a kneading machine to obtain a kneaded paste; and crushing the kneaded paste, carrying out hot press molding, and curing in a drying oven to obtain the carbon-graphite sealing material. The preparation process is simple, the production cost is low, the service performance of the obtained material is greatly improved, and the service life is greatly prolonged.

The invention provides a viscous damping device based on efficient heat dissipation, and belongs to the field of building anti-seismic equipment. The damper comprises a viscous damping assembly, an upper gusset plate and a lower gusset plate, the viscous damping assembly comprises a cylinder body, a piston rod, two bushings and a piston, the upper gusset plate is hinged to the end, located outside the cylinder body, of the piston rod, an upper mounting plate is fixedly mounted at the top of the upper gusset plate, and a connecting body is fixedly mounted at the end, away from the upper gusset plate, of the cylinder body; the lower gusset plate is hinged to the end, away from the cylinder body, of the connecting body, a plurality of heat conduction rods distributed in an annular array are slidably installed on the piston in a penetrating mode, and a plurality of natural graphite flakes are fixedly installed on the positions, close to the two ends, of the outer walls of the heat conduction rods. The viscous damping device based on efficient heat dissipation has the advantages that an efficient passive heat dissipation link is arranged in the cylinder body, active one-way auxiliary heat dissipation can be achieved, a heat dissipation fin convenient disassembly and maintenance structure is arranged, and the telescopic amplitude of the piston rod can be accurately recorded.

A negative electrode active substance layer of a negative electrode for nonaqueous electrolyte secondary battery herein disclosed includes at least a first negative electrode active substance and a second negative electrode active substance. The first negative electrode active substance is configured with an aggregated body of a scaly graphite whose surface of at least one part is covered with a low crystalline carbon. A graphite interlayer distance of the low crystalline carbon is equal to or more than 3.8 Å and not more than 5.0 Å. The second negative electrode active substance is a natural graphite or an artificial graphite whose graphite interlayer distance based on electron diffraction images by the transmission electron microscope is equal to or more than 3.35 Å and not more than 3.4 Å. Here, a mass ratio of the first negative electrode active substance and the second negative electrode active substance is 50:50 to 90:10.

To provide a negative electrode for a lithium secondary battery that contains a carbon-based negative electrode active material such as natural graphite, has little volume change during charge and discharge, and exhibits high charge and discharge rates and high energy density, and a method for manufacturing the same.SOLUTION: The present invention relates to a negative electrode for a lithium secondary battery and a method for manufacturing the same. The negative electrode includes a negative electrode active layer on a negative electrode current collector, and the negative electrode active layer is divided into a center region, an edge region, and a sliding region. The degree of alignment (O.I) of each carbon-based negative electrode active material contained in the center region, the edge region, and the sliding region satisfies Equation 1 and Equation 2. This results in little volume change during charge and discharge, and the negative electrode exhibits high-rate charge and discharge performance and high energy density.SELECTED DRAWING: Figure 1

The application provides a modification method of natural graphite, modified natural graphite and a lithium ion battery, and the modification method comprises the following steps: mixing unpurified natural graphite and a composite modifier, and performing reaction to obtain modified natural graphite; the composite modifier comprises any one or a combination of at least two of a composite strong oxidizing acid, a strong oxidizing gas or an ionic liquid; and the composite strong oxidizing acid comprises at least two strong oxidizing acids. The application provides a method which is low in cost, simple in process and capable of achieving the same oxidation treatment effect, the method combines the natural graphite purification process and the oxidation treatment process into one-step modification, thereby reducing the process, improving the production efficiency, achieving the purpose of reducing the cost, and the modified graphite has excellent initial efficiency and cycle stability.

The application belongs to the technical field of lithium ion battery cathode material, and particularly relates to a preparation device and method of graphene-coated lithium manganese iron phosphate cathode material, which comprises a graphene oxide powder preparation device, a feeding device and a mixing cavity. The graphene oxide powder preparation device prepares graphene oxide powder through the following steps: step A1, low-temperature pre-intercalation treatment, mixing and stirring natural graphite, concentrated sulfuric acid and oleum at low temperature to perform pre-intercalation; step A2, staged oxidation reaction, first adding an oxidizing agent to perform first-stage oxidation at low temperature, then performing second-stage oxidation at medium temperature, finally adding water and performing curing reaction at high temperature. The device solves the problems of complex preparation process of graphene-coated lithium manganese iron phosphate cathode material, and low quality of graphene oxide dispersion liquid formed by graphene oxide powder covering solvent, which affects the quality of graphene-coated lithium manganese iron phosphate cathode material.

The present application provides a kind of negative electrode for reducing the initial resistance of non-aqueous electrolyte secondary battery and achieving the improvement of durability.The negative electrode for non-aqueous electrolyte secondary battery disclosed herein has a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector, and the negative electrode active material layer at least contains a first negative electrode active material and a second negative electrode active material.The first negative electrode active material is composed of agglomerates of flaky graphite coated with low-crystallinity carbon on at least part of the surface, and the interlayer distance of graphite of the low-crystallinity carbon based on the electron diffraction image obtained by transmission electron microscopy is 0.3375 nm.The second negative electrode active material is natural graphite or artificial graphite with an interlayer distance of graphite based on the electron diffraction image obtained by transmission electron microscopy of 0.3375 nm.Here, the mass ratio of the first negative electrode active material to the second negative electrode active material is 50:50 to 90:10.