621 results about "Graphite particle" patented technology

The invention relates to the technical field of lithium batteries, and provides a lithium ion battery. The battery comprises a positive plate and a negative plate; a lithium iron phosphate (LFP) material in the positive plate is formed by mixing particles with different particle sizes, the negative plate adopts a double-layer coating design, the upper layer uses first graphite particles with smaller particle sizes, and the lower layer uses second graphite particles with larger particle sizes. The positive plate is matched with a double-layer coated negative plate, so that the lithium ion battery has relatively high energy density, good quick charge performance, rate capability and high-temperature storage performance.

A nonaqueous electrolyte secondary battery according to an aspect of the present disclosure includes: an electrode body in which a positive electrode plate and a negative electrode plate are wound with a separator interposed therebetween; and an exterior package which receives the electrode body, the negative electrode plate includes a negative electrode collector, a first negative electrode mixture layer formed on a winding inside first surface of the negative electrode collector, and a second negative electrode mixture layer formed on a winding outside second surface of the negative electrode collector, the first negative electrode mixture layer contains first graphite particles as a primary component, the second negative electrode mixture layer contains second graphite particles as a primary component, and the first graphite particles has an internal void rate lower than an internal void rate of the second graphite particles.

The invention belongs to the technical field of image data processing, and particularly relates to an automatic evaluation method and system for the metallographic spheroidization rate of a casting, and the method comprises the steps: constructing a global gradient field of a metallographic image of the casting; calculating a centripetal index by using a negative gradient vector and positioning a graphite particle physical center; determining a physical boundary based on the ratio of the tangential slip amount to the radial projection intensity on the ray path; obtaining a compactness index based on the consistency of the internal negative gradient vector and the radial direction; and the spheroidization score is calculated by combining the contour roundness and the compactness index, and the spheroidization rate is counted and output. According to the method, the problem that the internal crushing defect cannot be identified by the existing geometric scalar method is solved, and dual evaluation on the morphology and compactness of the graphite particles is realized.

The invention relates to a negative pole piece and a preparation method and application thereof.The negative pole piece comprises a current collector and a negative active layer arranged on at least one face of the current collector in the thickness direction, the negative active layer comprises a first active layer, a second active layer and a third active layer, the first active layer is attached to the surface of the current collector, and the second active layer is attached to the surface of the current collector; the second active layer is arranged on the surface, far away from the current collector, of the first active layer, and the third active layer is arranged on the surface, far away from the first active layer, of the second active layer; the first active layer comprises carbon-coated secondary particle graphite, the second active layer comprises heteroatom-doped hard carbon, and the third active layer comprises porous carbon nanofibers. According to the lithium ion battery, the multiple active layers containing different active materials are arranged on the surface of the current collector, and meanwhile, the thickness of each active layer is regulated and the preparation process is optimized, so that the lithium ion battery containing the negative pole piece has high energy density, quick charge capacity and excellent cycle life.

A lithium-ion secondary battery having excellent discharge characteristics even in a low-temperature environment is provided. The lithium-ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte solution. The positive electrode includes lithium cobalt oxide with a median diameter (D50) of greater than or equal to 1 μm and less than or equal to 12 μm. The lithium cobalt oxide contains magnesium in its surface portion. The negative electrode includes a graphite particle, a silicon particle, and a polymer including a carboxy group. The electrolyte solution contains a mixed solvent of a fluorinated cyclic carbonate and a fluorinated chain carbonate.

The invention relates to the field of batteries, in particular to a composite negative electrode material, a preparation method thereof and a battery, the composite negative electrode material comprises graphite particles and a coating layer coating the surfaces of the graphite particles; the graphite particles comprise acidified graphite particles, and the acidified graphite particles comprise graphite particles containing oxygen-containing functional groups; the coating layer comprises lithium niobate crystals; the chemical formula of the lithium niobate crystal is LixNbOy, x is more than 0 and less than or equal to 1, and y is more than 0 and less than or equal to 3. According to the composite negative electrode material disclosed by the invention, the desolvation energy barrier of lithium ions is reduced, and the transmission impedance at the interface of a negative electrode and electrolyte is reduced, so that the fast charging performance of graphite is improved.

The invention relates to a battery monomer, a battery device and a power utilization device. The battery monomer comprises a positive pole piece and a negative pole piece, the positive pole piece comprises lithium-containing phosphate; the negative pole piece comprises graphite particles; the electrolyte comprises a carboxylic ester solvent, a linear carbonic ester solvent and an additive, the mass content of the carboxylic ester solvent is 10%-30%, and the mass content of the linear carbonic ester solvent is 10%-50%; the mass content of the additive is 3%-9%, the additive comprises 1, 3-propane sultone with the mass content larger than or equal to 0, an ethylene carbonate derivative with the mass content larger than or equal to 0 and vinylene carbonate with the mass content larger than 0, and the ethylene carbonate derivative comprises a compound shown in the formula A; q1, Q2, Q3 and Q4 each independently comprise any one of a hydrogen atom, a halogen atom, a C1 to C5 alkyl group or a C1 to C5 halogenated alkyl group, and Q1, Q2, Q3 and Q4 are not hydrogen atoms at the same time. # imgabs0 # formula A is shown in the specification.

The invention relates to a lithium ion battery sectional type quick charging method for reducing polarization, which comprises the following steps of: firstly, carrying out stepped constant-current and constant-voltage charging on a battery cell: dividing into N constant-current and constant-voltage charging stages, and carrying out constant-current and constant-voltage charging in each constant-current and constant-voltage charging stage to a corresponding limited voltage or limited capacity; and performing constant-voltage charging on the battery cell until the final current is reached. In the charging process of the lithium ion battery, multi-stage capacity cut-off and multi-stage voltage termination are combined, the charging process is divided into multi-stage constant-current and constant-voltage charging, constant-current and constant-voltage charging in each stage reaches the limited voltage or the limited capacity, and the constant-current and constant-voltage charging is stopped until the voltage reaches the upper limit voltage of the battery. According to the sectional type rapid charging method, the polarization lithium concentration difference between the interior and the exterior of the graphite particles can be effectively eliminated, diffusion of lithium into the graphite particles can be improved, damage to the graphite structure can be avoided, the rapid charging time of the battery can be optimized, and the cycle performance of the battery can be improved.

The invention provides a treatment method for recovering high-purity graphite from black powder leaching residues. The treatment method comprises the following steps: removing impurity elements in graphite from the black powder leaching residues in a Joule heat flash evaporation manner; the black powder leaching residues obtained after impurity removal are put into a ball mill, liquid phenolic resin is added, full mixing is conducted, and ball milling is conducted; and putting the ball-milled mixture into flash evaporation Joule thermal equipment, and carbonizing and graphitizing the phenolic resin to obtain regenerated graphite. According to the method, the temperature of the black powder leaching residues can be increased within an extremely short time, metal impurities in the black powder leaching residues are gasified, and impurities in graphite are removed. Phenolic resin is used for carbonization and graphitization, generated disordered carbon can fill up particle cracks in waste graphite and internal lattice defects, a conductive network among graphite particles is established, a compact carbon layer is formed on the surface of graphite, and graphite structure transformation can also be induced in the step. The regenerated graphite obtained by the method is similar to commercial graphite in capacity and good in cycling stability.

The invention relates to a battery device and a power utilization device, the battery device comprises an electrode assembly and an electrolyte, the electrode assembly comprises a positive pole piece and a negative pole piece, the positive pole piece comprises a positive pole lug, a positive pole current collector and a positive pole active material layer, and the negative pole piece comprises a negative pole lug, a negative pole current collector and a negative pole active material layer; the positive electrode active material layer comprises lithium-containing phosphate of an olivine structure; the negative electrode active material layer comprises graphite particles of which the Dv50 is 8.5-13.5 [mu] m; the single-side coating weight of the negative electrode active material layer is 110 to 150mg / 1540.25 mm < 2 >; the positive tab is connected to one side of the positive current collector along the width direction of the positive pole piece, and the negative tab is connected to one side of the negative current collector along the width direction; the electrolyte comprises a silane-based additive, a lithium salt additive and an unsaturated ester additive. According to the invention, the energy density, rapid charging and use reliability of the battery device can be considered.

A negative electrode material for a lithium-ion secondary battery comprising graphite particles satisfying, in a ratio of R value, which is an intensity ratio Id / Ig of a maximum peak intensity Ig in the range of 1580 cm-1 to 1620 cm-1 and a maximum peak intensity Id in the range of 1300 cm-1 to 1400 cm-1 in a Raman spectrum obtained by a Raman spectroscopy measurement, a ratio of the particles with R≥0.2 is 10% by number or more, and an average value of a half width of Id in the top 10 spectra with R values is 60 cm-1 or less.

Battery device comprising a thermal insulation element and at least two battery cells arranged along a first direction, wherein the battery cell comprises an electrode assembly and electrolyte solution, the electrode assembly comprising positive electrode plates and negative electrode plates, the positive electrode plate comprising positive current collectors and positive film layers arranged on at least one side of the positive current collectors, the positive film layer comprising lithium phosphate, wherein the negative electrode plate comprises negative current collectors and negative film layers arranged on at least one side of the negative current collector, the negative film layer comprising graphite particles. characterized in that the electrolyte solution comprises fluorosulfonylimide salt, wherein the mass fraction of the fluorosulfonylimide salt in the electrolyte solution is 2% to 12%; wherein the battery cell comprises two first surfaces which are opposite each other along the first direction, wherein the thermal insulation element covers at least one of the two first surfaces and the dimension of the thermal insulation element along the first direction is 0.3 mm to 5 mm.

Provided is a negative electrode material for a lithium-ion secondary battery, said material comprising graphite particles that satisfy formula (1) below.　(1) y + 50x ≤ 94 In formula (1), x is the tap density (g / cm3) of graphite particles after 250 times, and y is the oil absorption amount (mL / 100g) of graphite particles.

The invention discloses an electroplated part, an electroplated part manufacturing method and a connector. The electroplated part comprises a base material; a nickel plating layer formed on the surface of the base material; the tin-graphite composite plating layer is formed on the nickel plating layer; the nickel plating layer is formed on the base material, the tin-graphite composite plating layer is formed on the nickel plating layer, the tin plating layer is formed on the tin-graphite composite plating layer, the nickel plating layer serves as a bottom plating layer of the base material, the tin plating layer serves as an outer plating layer of the base material, and the tin-graphite composite plating layer serves as a middle plating layer of the base material. According to the invention, the graphite particles exposed from the tin-graphite composite coating are partially or completely wrapped by the outermost tin coating, so that the graphite particles are not easy to fall off, the wear resistance and corrosion resistance of the electroplated part are improved, and the service life of the electroplated part is prolonged. In addition, the plating layer structure also has a relatively low friction coefficient, so that the insertion and extraction force of the electroplated part in the use process can be greatly reduced.

The invention provides a surface modified carbon negative electrode material, a preparation method thereof and a battery. The preparation method comprises the following steps: mixing a graphite carbon source and a pore-forming agent, and graphitizing the obtained mixture to form porous graphite; performing oxidation treatment on the porous graphite to prepare porous graphite oxide particles; the porous graphite oxide particles are placed in a tin source solution containing tin cations, the tin source solution is attached to the surfaces of holes of the porous graphite oxide particles, and tin oxide attached to the surfaces of the holes of the porous graphite oxide particles is formed based on the tin source solution; and the porous graphite oxide particles are placed in a carbon-containing reducing gas environment to be subjected to calcination treatment, and the carbon-coated tin nanowires are prepared on the basis of the tin oxide. According to the preparation method, the surface and holes of the carbon negative electrode material are modified by adopting the carbon-coated tin nanowires, so that the discharge performance of the battery at relatively high rate can be effectively improved.

The invention belongs to the technical field of lithium ion negative electrode materials, and particularly relates to a graphite negative electrode material and a preparation method thereof. The graphite negative electrode material comprises: (1) a three-dimensional porous graphite sheet layer matrix; (2) a nitrogen-doped amorphous carbon layer coated on the surfaces of the graphite particles, wherein the nitrogen element exists in the form of pyridine nitrogen and graphite nitrogen; and (3) after the material is subjected to CO2 atmosphere heat treatment, an aperture micropore structure is formed on the surface. The preparation method comprises the following steps: (1) carbonizing raw materials; (2) crushing treatment; (3) wrapping and granulating; (4) high-temperature treatment; and (5) performing subsequent treatment. According to the invention, the interface stability is obviously improved, the ion diffusion kinetics is optimized, the cycle life of the battery is obviously prolonged, the uniformity and process stability of the coating layer are improved, the energy consumption of high-temperature treatment is reduced, and the comprehensive performance and suitability of the battery are obviously optimized by reasonably controlling the capacity ratio of the positive electrode and the negative electrode and the content of a specific additive in the electrolyte.

Provided is a negative electrode material for a lithium-ion secondary battery, the negative electrode material being composed of graphite particles satisfying the following formulas (1) to (5), where x (kN / cm2) is the compression load, which is the magnitude of the pressure required to compress the graphite particles to a density of 1.7 g / cm3, and y is the springback ratio.　Formula (1): x + y × 7.6 ≤ 4.50 (1.0 ≤ x ≤ 2.5). Formula (2): x + y × 8.8 ≥ 3.45 (1.0 ≤ x ≤ 2.5). Formula (3): –x + y × 60.8 ≥ 4.00 (2.5 ≤ x ≤ 5.0). Formula (4): –x + y × 55.8 ≤ 12.00(2.5 ≤ x ≤ 5.0). Formula (5): y ≤ 0.270.

Provided is a negative electrode material for a lithium-ion secondary battery, said material being graphite particles that satisfy (1) and (2) below. (1) The slope k of a linear approximation line, in which the electrode density d (g / cm3) is the explanatory variable and the orientation I002 / I110, defined as the ratio of the peak intensity (I002) of the (002) diffraction line to the peak intensity (I110) of the (110) diffraction line obtained by X-ray diffraction measurement, is the objective variable, is 930 or less. (2) The compressive load, which is the magnitude of pressure required to compress the material to a density of 1.7 g / cm3, is 1.85 kN / cm2 or more.

The invention provides a medium-temperature pitch proportion optimization method and system for a graphite electrode, and relates to the field of material engineering. The medium-temperature pitch proportion optimization system for the graphite electrode comprises a proportion analysis module which establishes a proportion model of graphite electrode production through mathematical modeling and data analysis according to the particle size distribution of graphite particles and the viscosity and softening point characteristics of pitch, can analyze various parameters in the production process of the graphite electrode in real time, and can optimize the proportion of the pitch in the graphite electrode production process; the optimal asphalt ratio range is calculated; and the data acquisition module is used for acquiring data of key parameters in the production process, including the size, temperature and humidity of graphite particles and the viscosity of asphalt, and is connected with the central control system through a sensor to transmit the data in real time for further analysis. Through the accurate asphalt proportion and optimization process, the strength, thermal stability, oxidation resistance and other physical properties of the graphite electrode can be effectively improved, and the rejection rate is reduced.

The invention relates to a battery monomer, a battery device and a power utilization device, the battery monomer comprises an electrode assembly and an electrolyte, and the volume average particle size Dv50 of graphite particles of a negative electrode active material layer is 7.8-12.5 [mu] m; the electrolyte comprises a carboxylic ester solvent with the mass content of 8%-30%, a cyclic carbonate solvent with the mass content of 25%-35% and a linear carbonate solvent with the mass content of 18%-45%, and the linear carbonate solvent comprises dimethyl carbonate, an unsaturated ester additive with the mass content of 0.05%-5% and a lithium salt additive with the mass content of 0.2%-1.5%; the amount of electrolyte in the battery cell is 2.8 g / Ah to 3.2 g / Ah. According to the invention, rapid charging and use reliability of the single battery can be considered.

An energy storage device according to an aspect of the present invention includes an electrode assembly in which a positive electrode including a positive active material layer and a negative electrode including a negative active material layer are stacked with each other with a separator interposed therebetween, in which the positive active material layer contains a positive active material particle, and the positive active material particle has an internal porosity of 15% or less, and the negative active material layer contains a graphite particle, and the graphite particle has an internal porosity of 2% or less.

The purpose of the present invention is to provide a gas diffusion electrode which reduces electrical resistance in a thickness direction without impairing gas diffusibility, and improves power generation performance when used in a fuel cell. The present invention relates to a gas diffusion electrode having a microporous layer on at least one surface of a conductive porous substrate. The gas diffusion electrode is characterized in that the microporous layer includes carbon black and graphite particles with an aspect ratio of 10 or more, and the ratio of the thickness of a portion in which the microporous layer is sunk of the conductive porous substrate to the thickness of a portion in which the microporous layer is not sunk of the conductive porous substrate is 5-20% inclusive.

This negative electrode material for a lithium ion secondary battery contains a plurality of graphite particles. In three-dimensional image data of the plurality of graphite particles obtained by X-ray CT measurement, the moments of the center of mass determined from mutually orthogonal principal axes of inertia with respect to the graphite particles are denoted as L, M, and S, with the maximum value L being set to 1. Among the graphite particles having a particle diameter of 15 μm or more, the proportion of the particles according to (1) below is 32% or more by number, and the proportion of the particles according to (4) below is 65% or less by number. (1) L = 1, 0.5 < M < 1.0, and 0.5 < S < 1.0 are satisfied. (2) L = 1, 0.7 < M < 1.0, and S < 0.3 are satisfied. (3) L = 1, M < 0.3, and S < 0.3 are satisfied. (4) None of (1) to (3) are satisfied with respect to the moments L, M, S of the center of mass.

The invention relates to a battery monomer, a battery device and a power utilization device, the battery monomer comprises an electrode assembly and an electrolyte, the electrode assembly comprises a positive pole piece, an isolating membrane and a negative pole piece, the positive pole piece comprises a positive current collector and a positive active material layer arranged on at least one side of the positive current collector, the positive pole piece comprises a positive pole current collector and a positive pole active material layer arranged on at least one side of the positive pole current collector, the negative pole piece comprises a negative pole current collector and a negative pole active material layer arranged on at least one side of the negative pole current collector, the positive pole active material layer comprises lithium-containing phosphate with an olivine structure, the negative pole active material layer comprises graphite particles, and the compaction density of the negative pole active material layer is 1.2 g / cm < 3 >-1.6 g / cm < 3 >; the electrolyte comprises a carboxylic ester solvent, the mass content of the carboxylic ester solvent in the electrolyte is 8%-30%, the electrolyte further comprises an unsaturated ester additive, and the mass content of the unsaturated ester additive in the electrolyte is 0.05%-3%. According to the invention, the energy density, rapid charging and use reliability of the battery monomer can be considered.

Provided is a negative electrode material for a lithium-ion secondary battery, said material being graphite particles that satisfy formula (1) below.　(1) 0.01 y + 76.19x ≤ 256.75 In formula (1), x is the average surface interval (d002, unit Å) of graphite particles determined by an X-ray diffraction method, and y is the crystallite size Lc (nm) of graphite particles.

Provided is a negative electrode material for a lithium-ion secondary battery comprising graphite particles, wherein when a coating film is formed so that the coating amount after drying is 35.0 ± 0.2 mg / cm2 by means of the doctor blade technique using a slurry containing the graphite particles, a density d of the coating film after drying is 1.10 g / cm3 to 1.40 g / cm3.

The invention relates to the technical field of graphite negative electrode materials for lithium ion batteries, a surface coating layer structure of the graphite negative electrode material is finely designed to obtain a fast-charging graphite negative electrode material, the fast-charging graphite negative electrode material is provided with a core-shell structure, the core-shell structure takes graphite particles as an inner core, and the surface of the inner core is provided with a carbon coating layer with an ultra-micro pore structure; the pore opening diameter of the ultra-micro pore structure is 0.3-2.0 nm, the pore cavity diameter of the ultra-micro pore structure is 0.5-3.0 nm, and the pore opening diameter of the pore opening is smaller than the pore cavity diameter. A coating layer with an ultra-micro pore structure is introduced to the surface of the graphite negative electrode material, and the structural characteristics of pore cavities and pore openings in the ultra-micro pore structure are finely designed, so that the desolvation speed of lithium ions in an electrolyte on the surface of the material is increased, and the interface structure stability of the graphite negative electrode material can be effectively improved in the process; therefore, the fast charging performance and the cycle performance of the graphite negative electrode material can be effectively improved.

The invention discloses a negative electrode material, a negative electrode plate prepared from the negative electrode material, and a secondary battery, and belongs to the technical field of electrochemical energy storage. And the size of the silicon-carbon particles and the thickness of the coating layer are synchronously regulated and controlled based on the particle size difference of the graphite particles, so that the material not only can realize ideal cycle stability when being applied to the negative electrode material of the secondary battery, but also has excellent floating charge performance.

Embodiments described herein relate to methods of producing electrodes. In some aspects, a method can include mixing a plurality of layered particles with a plurality of non-layered particles. The method further includes milling the plurality of layered particles and the plurality of non-layered particles in a controlled environment to form a composite. The method further includes forming the composite into an electrode. In some embodiments, the controlled environment has a pressure of no more than about 0.3 bar absolute. In some embodiments, the controlled environment can include at least about 99.9 vol% of an inert gas. In some embodiments, the plurality of layered particles can include graphite particles. In some embodiments, the plurality of non-layered particles can include silicon particles.

The non-aqueous electrolyte secondary cell according to an embodiment of the present disclosure has a positive electrode, a negative electrode, and a non-aqueous electrolytic solution. The negative electrode has a negative electrode collector and a negative electrode active material layer provided on the negative electrode collector. The negative electrode active material layer contains graphite particles A and graphite particles B as negative electrode active materials. The graphite particles A have an internal void rate of 5% or below. The graphite particles B have an internal void rate of 8 to 20%. When the negative electrode active material layer is halved in the thickness direction, a region on the half closer to the outer surface contains more graphite particles A than a region on the half closer to the negative electrode collector.