638results about "Graphite" patented technology

The invention belongs to the field of negative electrode materials, and particularly relates to a silicon-graphite composite material, a preparation method and application thereof and a lithium ion battery, the preparation method comprises the following steps: mixing and slurrying silicon powder, graphite and a composite functional additive, and then carrying out ball milling modification to obtain primary composite particles; the composite functional auxiliary agent comprises an auxiliary agent A, an auxiliary agent B and an auxiliary agent C; the primary composite particles and a carbon source liquid phase are compounded and then subjected to spray drying and heat treatment, or spray pyrolysis is directly carried out, and secondary composite particles are prepared; and carrying out modification treatment on the secondary composite particles prepared in the step 2 in a surface modification liquid, and then carrying out low-temperature annealing at 150-300 DEG C to prepare the silicon-graphite composite material. The surface modification liquid is an organic solution in which conductive lithium salt and an auxiliary agent D are dissolved. Based on the combined control of the preparation process and the structure, the silicon-based negative electrode material with ultra-long cycle life and excellent low-temperature fast charging performance can be obtained.

Provided in the present disclosure are a negative electrode sheet, a secondary battery, an electric device, and a negative electrode active material and a preparation method therefor. The negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer located on at least one surface of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material. The negative electrode active material comprises first artificial graphite and second artificial graphite, wherein the first artificial graphite comprises primary particles, and the second artificial graphite comprises secondary particles. The powder OI value of the negative electrode active material is 2.5-6.5; and the powder compaction density of the negative electrode active material under a pressure of 50,000 N is 1.75-1.94 g / cc.

The invention provides a hydrophilic modified porous graphite-based phase change heat storage material and a preparation method thereof, and relates to the technical field of phase change heat storage materials. The hydrophilic oxide layer is constructed on the pore surface of the porous graphite, so that the porous graphite is changed from hydrophobicity to hydrophilicity, and the application limitation caused by original strong hydrophobicity is effectively overcome. The oxide layer is stable in property in a high-temperature environment, the applicable temperature range of the material is remarkably widened, erosion of oxygen to a carbon skeleton can be blocked, the structural integrity of the porous graphite is protected, and the service life of the material is prolonged. The high-enthalpy polar phase change material can be efficiently compounded with the hydrophilic modified porous graphite in a solution spontaneous impregnation manner by virtue of good flowability and permeability of an aqueous solution of the high-enthalpy polar phase change material, so that the preparation process is greatly simplified. The finally prepared hydrophilic modified porous graphite-based phase change heat storage material has high thermal conductivity and high heat storage density, shows excellent comprehensive performance, and solves the problem that a polar phase change substance with a high enthalpy value is difficult to be effectively compounded with porous graphite.

The invention relates to a multi-conductive-agent composite conductive paste for a lithium battery and a preparation method of the multi-conductive-agent composite conductive paste, and belongs to the technical field of lithium battery conductive pastes.The multi-conductive-agent composite conductive paste is characterized in that an iron-molybdenum catalyst is loaded on expanded graphite, then vertical orientation carbon nanotubes and transverse graphene blades are grown in situ, the specific surface area is increased, and the expanded graphite serves as a layered carrier; a metal alloy catalyst can be uniformly loaded in natural pores of the carbon nanotube, a layered framework is kept from collapsing at a high temperature, support is provided for directional growth of a carbon material, electrons can be rapidly transmitted along the carbon nanotube when the composite conductive paste is prepared, gaps of the carbon nanotube are filled by graphene blades, a breakpoint-free conductive network is formed, and the composite conductive paste is prepared. And meanwhile, abundant pores provide channels for lithium ion diffusion, so that the conductive efficiency is improved from the source of the structure, and abundant specific surface area and subsequent nitrogen and sulfur loading provide sufficient sites.

The invention relates to an S-doped g-C3N4 coated modified graphite material, a preparation method thereof and a lithium ion battery negative electrode. The method comprises the following steps: mixing a g-C3N4 precursor with a sulfur source, and then carrying out heat treatment under the condition of shielding gas to obtain sulfur-doped graphite phase carbon nitride S-g-C3N4; carrying out plasma modification treatment on the surface of the graphite material by adopting plasma reaction gas to obtain modified graphite; mixing S-g-C3N4 with the modified graphite to obtain a mixed material; and calcining the mixed material in a protective gas environment to obtain the S-doped g-C3N4 coated modified graphite material. The invention also provides the graphite material prepared by the method and a lithium ion battery negative electrode prepared from the graphite material. The graphite material has relatively high conductivity, interface compatibility and structural stability.

An anode material and a battery provided. The anode material includes artificial graphite, and there are pores inside and / or on surface of the artificial graphite. The anode material has an oil absorption value of O mL / 100g, a pore volume of V cm3 / kg, and a specific surface area of S m2 / g, where 400 ≤ O*V*S ≤ 1500. The anode material improves adsorption and infiltration performance of the anode material to electrolyte, and enhance high rate charge-discharge performance of the anode material, without affecting processing performance.

The present application provides a graphite material and a preparation method therefor, a secondary battery, and an electric device. The crystallite size La along the a-axis direction of the graphite material ranges from 135 nm to 150 nm.

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.

To provide a method of forming highly spherical carbon nanomaterial-graft-polyolefin (CNM-g-polyolefin) particles.SOLUTION: The method may comprise: mixing a mixture comprising (a) a carbon nanomaterial-graft-polyolefin (CNM-g-polyolefin), (b) a carrier fluid that is immiscible with the polyolefin of the CNM-g-polyolefin, optionally (c) a thermoplastic polymer not grafted to a CNM, and optionally (d) an emulsion stabilizer at a temperature higher than a melting point or softening temperature of the polyolefin of the CNM-g-polyolefin and the thermoplastic polymer, if included, and at a shear rate sufficiently high to disperse the CNM-g-polyolefin in the carrier fluid; cooling the mixture to below the melting point or softening temperature to form the CNM-g-polyolefin particles; and isolating the CNM-g-polyolefin particles from the carrier fluid.SELECTED DRAWING: Figure 1

To provide graphite materials that guarantee excellent initial efficiency and rapid charging performance, and that combine excellent self-discharge performance, capacity performance, and cycle performance, as well as methods for producing them, electrochemical apparatus, and electronic equipment. [Solution] The graphite material satisfies the following conditions: La ≤ 72 nm, Lc ≤ 15 nm. Here, La is the lattice constant at the 110 plane of the graphite crystal in the graphite material, and Lc is the lattice constant at the 002 plane of the graphite crystal in the graphite material. F ≥ 15 mN. F is the particle crushing force.

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.

This invention discloses a transition metal sulfide intercalated graphite, its preparation method, and its applications, belonging to the field of materials science and technology. Utilizing the characteristics of a two-chamber system, a synthesis strategy based on temperature and time differences is adopted. Pretreated transition metal chlorides are uniformly mixed with flake graphite and then subjected to heat treatment. By introducing low-melting-point nitrates, the mechanical energy from ball milling is converted into internal energy, allowing the reaction system to reach the eutectic temperature and initially activating the flake graphite, significantly shortening the reaction time. Simultaneously, sublimed sulfur is used as a sulfur source for sulfidation treatment, synthesizing transition metal sulfide intercalated graphite in one step. Unlike traditional methods that first synthesize transition metal chloride intercalated graphite and then perform secondary processing to obtain transition metal sulfide intercalated graphite, the transition metal sulfide intercalated graphite obtained by this invention has advantages such as low cost, simple process, convenient preparation, high reproducibility, no impurity phases in the product, and high sulfidation rate, making it directly applicable to the field of electromagnetic wave absorption.

A method for producing graphene. The method includes the steps of supporting particulate graphite on an open-cell porous framework material, immersing at least a portion of the graphite-supported porous framework material in a solution, and applying a cathode potential to the graphite-supported porous framework material, wherein the cathode potential is sufficient to exfoliate the graphene.

In electromagnetic wave shielding materials, this prevents tears and pinholes caused by bending, thereby maintaining electromagnetic wave shielding properties. [Solution] An electromagnetic wave shielding material (2) is made of an expanded graphite sheet (1) having a surface treatment structure at least in the portion to be folded that facilitates folding and prevents breakage. The surface treatment structure is a roughened structure with minute irregularities formed on one or both sides.

The invention relates to the technical field of batteries, in particular to a negative electrode material and a preparation method thereof, a negative electrode plate, a battery and an electric device. The preparation method of the negative electrode material comprises the following steps: mixing a first inorganic salt compound and a second inorganic salt compound, and adding the mixture into a first solvent to form a salt solution; adding the etched graphite into a salt solution, mixing, and drying to obtain an intermediate material; the first inorganic salt compound comprises a molybdenum compound; mixing alkali, a first binder and the intermediate material, and carrying out first sintering to obtain porous graphite; and mixing a lithium compound, a second binder and silane, adding the mixture into a second solvent to form a mixed solution, dispersing the porous graphite into the mixed solution, and carrying out second sintering to obtain the negative electrode material. According to the negative electrode material obtained through the method, the specific capacity and the diffusion coefficient of the negative electrode material are effectively improved, and the cycle rate performance is well improved.

A graphite purification system contains a vessel adapted to contain graphite particles, including an inductive coil for heating said vessel; and a cooling system for cooling said graphite purification system, whereby the cooling system is adapted to also cool the graphite particles. The purification system may be a continuous or batch system, and, the vessel may be at least partially formed from graphite. A process for purifying graphite particles is also presented and includes providing a vessel formed at least partially from graphite; loading graphite particles into the vessel; inductively heating at least a portion of the vessel, and thereby heating the graphite particles in physical contact with the vessel; and cooling the vessel and the graphite particles.

The invention relates to a carbonaceous material and a preparation method thereof, and a secondary battery and an electric device containing the carbonaceous material, the adsorption rate v of the carbonaceous material is greater than or equal to 0.015 and less than or equal to 0.050 when the carbonaceous material is subjected to an adsorption test by using water vapor under the conditions of constant temperature and humidity of 25 DEG C and 40% RH, and the water vapor adsorption test is carried out under the following conditions: in a constant temperature and humidity chamber of 25 DEG C and 40% RH, the adsorption rate v is greater than or equal to 0.015 and less than or equal to 0.050; a carbonaceous material with the mass of m1 is placed in a container, the water vapor adsorption mass m2 and the water vapor adsorption time t when the carbonaceous material adsorbs water vapor to be balanced are recorded, the water vapor adsorption rate v is equal to m2 / (m1 * t), the measurement unit of m1 is g, the measurement unit of m2 is g, and the measurement unit of t is h. The carbonaceous material can give consideration to relatively high gram volume, relatively high first coulombic efficiency and relatively high structural stability.

The invention relates to the technical field of composite functions, in particular to a NiCo2O4 nanosheet array modified expanded graphite heat storage-wave absorption integrated material and a preparation method thereof. According to the invention, an EG surface functional group is innovatively used as a nucleation site, and a precursor is guided to carry out anisotropic growth and oriented self-assembly in a limited space through a hydrothermal reaction, so that a precursor with a specific morphology (rod cluster shape) is formed; and through topological conversion, the NiCo2O4 nanosheets are firmly and uniformly converted into the honeycomb NiCo2O4 nanosheet array on the EG skeleton. The in-situ growth strategy ensures that strong chemical combination and tight physical contact are formed between the functional nano material and the conductive skeleton, and skeleton-absorbent function integration is realized. And the subsequent vacuum impregnation process further realizes directional transportation and spatial confinement solidification of the phase change material in the graded pore channel through interface energy gradient and capillary acting force, and finally, precise compounding and efficient cooperation of the'heat storage-wave absorption 'dual functions on the micro-scale are completed.

The composite filler filler forms a core-shell structure composed of a core substance made of carbon, metal, zinc oxide or zirconium oxide and a shell substance attached to a surface of the core substance. The shell substance is formed from fumed oxide particles, the fumed oxide particles being attached to a part or a whole of the surface of the core substance by mixing of the fumed oxide particles and the core substance in a dry ball mill. The fumed oxide particles are particles changed from bulky aggregated particles to gathered bulk particle. In the composite filler, percentage of the core substance ranges from 30 vol % to 85 vol % and percentage of the shell substance ranges from 15 vol % to 70 vol %, a thermal conductivity is 0.075 W / m·K or more, a volume resistivity is 1.0×105 Ω·cm or more, and a dielectric breakdown voltage is 1 kV / mm or more.

Carbon particles comprising at least 97 wt% carbon, based on the total weight of the carbon particle, at most 0.2 wt% impurities, based on the total weight of the carbon particle, at least 0.08 wt% boron, based on the total weight of the carbon particle, and at most 0.05 wt% boron carbide, based on the total weight of the carbon particle.

The claimed invention is directed to a catalytic graphitization process to convert fuel-grade petroleum coke into battery-grade graphite using a recyclable catalyst derived from iron, nickel or cobalt.

The invention belongs to the technical field of nano materials, and particularly relates to a nitrogen doping method and application of gamma-graphdiyne. Graphdiyne oxide is prepared through a hydrothermal method, then melamine serves as a nitrogen source, graphdiyne oxide serves as a framework, in-situ doping of nitrogen elements and reduction of graphdiyne oxide are achieved at the same time through high-temperature calcination, and the gamma-graphdiyne is obtained. The method is simple and easy to implement, the processing period is short, the doping amount is easy to control, dangerous chemicals such as concentrated sulfuric acid and concentrated nitric acid are not involved, the production safety is greatly improved, and the prepared nitrogen-doped gamma-graphdiyne has the advantages of high purity, high specific surface area, nanoscale pore diameter and excellent wave absorbing performance, gas sensitivity and ferromagnetism.

The invention provides aluminum oxide secondary coated high-magnification artificial graphite and a preparation method thereof.The preparation method comprises the steps that after artificial graphite and phenolic resin are subjected to liquid phase coating, carbonization treatment is conducted, and hard carbon primary coated artificial graphite is obtained; and mixing and coating the hard carbon primary coated artificial graphite and aluminum salt, and then carrying out heat treatment to obtain the aluminum oxide secondary coated high-magnification artificial graphite. According to the invention, artificial graphite and phenolic resin are used as raw materials, and are subjected to liquid-phase coating and high-temperature treatment to prepare artificial graphite coated with hard carbon once; and then the hard carbon primary coated artificial graphite and the aluminum salt are mixed and coated, and aluminum oxide secondary coated high-magnification artificial graphite is prepared through high-temperature treatment, so that the magnification performance of the graphite material can be effectively improved, and relatively good cycle performance can be ensured.

The application prepares an NP co-doped graphite nanosheet electrocatalyst, and has the advantages of simple and efficient preparation method, easy operation, low cost and practical application significance. The application takes cheap graphite powder as raw material, takes melamine and sodium hypophosphite as nitrogen source and phosphorus source respectively, and prepares the NP co-doped graphite nanosheet in a tube furnace through a high-temperature gas phase method. The NP co-doped graphite nanosheet is activated by electrochemistry to generate adjacent quinone structures with basic OER activity and further oxidize P-containing functional groups to obtain more phosphoric acid functional groups with HER activity, and the NP co-doped graphite nanosheet exhibits excellent electrocatalytic performance. The overpotential of the basic OER is only 314 mV, and the overpotential of the acidic HER is only-69.4 mV.

A method for producing graphene. The method includes loading an open-cell porous backbone material with particulate graphite, submersing at least part of the graphite-loaded porous backbone material in a solution, and applying a cathodic potential to the graphite-loaded porous backbone material, wherein the cathodic potential suffices to exfoliate graphene.

The invention relates to the technical field of resource recycling and high-value utilization of lithium ion batteries, in particular to a technology for generating, recycling or refining metal through an electrolytic method. The invention discloses a method for synthesizing a manganese ferrite magnetic material from a waste lithium manganese iron phosphate positive electrode material. The method comprises the following steps: preparing waste lithium manganese iron phosphate positive electrode powder, an organic binder and a solvent into slurry, and coating the surface of a titanium mesh with the slurry to obtain a positive plate; constructing an electrolytic tank by taking a blank titanium mesh as a negative electrode and a NaOH aqueous solution as an electrolyte, carrying out electrolytic leaching to obtain Li and P elements, concentrating the electrolyte, supplementing a phosphorus source, and adjusting the pH value to recover lithium phosphate; the method comprises the following steps: ultrasonically separating ferromanganese / graphite remained on a titanium mesh, acidizing and dissolving, filtering to remove graphite, adding citric acid into filtrate for gelation, and subsequently calcining to obtain the manganese ferrite magnetic material. According to the method, efficient leaching of Li and P is achieved through electrochemical treatment, Mn and Fe are synchronously converted into high-crystallinity manganese ferrite in a high-valued mode, and the method has the advantages of being environmentally friendly, low in consumption and capable of achieving all-element closed-loop recovery.

A conveying device for conveying material, in particular material having a temperature of 1500° C. to 3200° C., in particular for conveying thermally or thermo-chemically treated material, has a housing which has a material inlet and a material outlet. The material can be conveyed from the material inlet to the material outlet along a conveying path by means of a conveying device. Along the conveying path, such surfaces that come into contact with the material to be conveyed are provided, at least in certain areas, by a material that is a graphite material or a material with graphite-like properties.

This invention provides a modified artificial graphite material, its preparation method, applications, and secondary batteries. The modified artificial graphite material comprises a graphite crystal matrix and a functionalized carbon composite layer encapsulating the graphite crystal matrix. The functionalized carbon composite layer contains amorphous carbon, carbon surface defects, and oxygen-containing functional groups. Raman spectroscopy reveals the presence of Ig in the spectrum. D / I G The peak area ratio is 0.30–0.60, I D The representative is located at 1350cm ‑1 peak D at location I G The representative is located at 1580cm ‑1 The G peak at [location]. In the Raman spectrum, I [value missing]. D / I G A peak area ratio of 0.30–0.60 indicates that the disorder of amorphous carbon is within a certain range. A certain degree of amorphous carbon can provide more lithium-ion diffusion channels, thus improving fast charge / discharge performance, and can also avoid excessive disorder affecting graphite performance. Carbon surface defects can increase specific surface area to improve material capacity. A functionalized carbon composite layer containing amorphous carbon, carbon surface defects, and oxygen-containing functional groups, encapsulating the surface of the graphite crystalline matrix, can reduce the rebound rate and increase the compaction density.

The invention belongs to the technical field of artificial diamond processing, and relates to a raw material pretreatment device and method applied to an artificial diamond synthesis process, and the method comprises the following steps: selecting graphite powder with the purity not lower than 99.9% as a carbon source main material, screening through a 100-mesh standard sieve, removing coarse particles with the particle size larger than 150 microns and impurities, and collecting screen underflow for later use; meanwhile, metal catalyst powder with the particle size of 5-10 microns is selected, the screened graphite powder is placed in plasma treatment equipment, inert gas is input to drive the graphite boat body to rotate in the furnace, it is ensured that all the surfaces of the biscuit can make continuous and uniform contact with the high-temperature inert gas, and therefore the sintering temperature of the biscuit is increased; the problem of uneven heating caused by the near-heat and far-cold effect in the static oven is fundamentally solved; and the biscuit is uniformly dehydrated and purified in all-dimensional hot air flow, so that insufficient pretreatment caused by local overheating or insufficient temperature is effectively avoided, and the quality stability of a final artificial diamond product is greatly improved.

This invention discloses a microwave preparation method for sulfur-free expanded graphite and its application, belonging to the field of carbon material preparation technology. The method includes four steps: raw material pretreatment, sulfur-free intercalation treatment, microwave expansion treatment, and post-treatment. This invention selects high-carbon natural flake graphite, which is pretreated by crushing and drying. Then, an intercalation reaction is carried out by adding a sulfur-free oxidant and a composite intercalation solution. Following microwave heating for rapid expansion, the finished sulfur-free expanded graphite is obtained after post-treatment. This invention innovatively adopts a sulfur-free intercalation system, completely eliminating sulfur residue and pollution. Combined with microwave heating technology, energy consumption is reduced by more than 60% compared to traditional processes. The process is simple and the production cycle is short. The obtained product has an expansion volume ≥300mL / g, a sulfur content ≤0.01%, high purity, and stable performance. It can be widely used in multiple fields, solving the problems of sulfur pollution, high energy consumption, complex processes, and limited applications of existing technologies, and has significant economic and environmental benefits.