762 results about "Graphite particle" patented technology

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 electrode assembly comprises a positive pole piece and a negative pole piece; the positive pole piece comprises lithium-containing phosphate with an olivine structure; the negative pole piece comprises graphite particles; the electrolyte comprises a carboxylic ester solvent and a first additive, the thickness of the single-side negative electrode film layer is 50 microns to 75 microns, and the volume average particle size of the graphite particles is 8.5 microns to 13.5 microns; based on the mass of the electrolyte, the mass content of the carboxylic ester solvent is 8%-60%, the total mass content of the first additive is 3%-10%, the first 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 or equal to 3%, and the ethylene carbonate derivative comprises a compound shown in the formula A. According to the invention, the rapid charging performance and the cycle performance of the battery monomer under high energy density can be improved. # imgabs0 # formula A

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.

The invention relates to the technical field of smashing devices, in particular to a smashing device for a graphite lithium battery negative electrode material, which comprises a shell, the interior of the shell is divided into a smashing cavity and a storage cavity, and a storage part with a hollow structure is arranged in the storage cavity; the crushing and conveying mechanism is used for conveying external graphite particles to the crushing cavity and carrying out coarse crushing on the graphite particles in the conveying process; the crushing mechanism is used for crushing the graphite particles; the driving mechanism is used for transmitting power to the crushing mechanism, and meanwhile, the air and the graphite particles in the crushing cavity are conveyed into the storage part in the power transmitting process; and the screening plate is installed in the storage part, an outlet is formed in the storage part, and the storage part communicates with the crushing cavity through a circulating pipe. Graphite particles are conveyed into the crushing cavity through the crushing and conveying mechanism, then the driving mechanism is used for driving the crushing mechanism to crush the graphite particles, and finally the graphite particles are screened through the screening plate, so that the crushing efficiency of the graphite particles and the uniformity of the crushing granularity are improved.

The invention discloses a lithium ion battery negative pole piece, a preparation method thereof and a lithium ion battery, and belongs to the technical field of lithium ion battery electrode materials. The lithium ion battery negative electrode plate provided by the invention comprises a negative electrode current collector; the graphite layers are arranged on the surfaces of the two sides of the negative electrode current collector; the graphite layer comprises graphite particles, a conductive agent and a binder; the hard carbon layer is arranged on the surface of one side, far away from the negative electrode current collector, of the graphite layer; the hard carbon layer comprises hard carbon particles, a conductive agent and a binder; wherein the graphite layer and the hard carbon layer meet the relational expression: 1.4 < = rho1 * D1 + rho2 * D2 + PD < = 1.75. According to the invention, through proper design of the composite layer structure, the surface density, the compaction density and the particle sizes of the graphite particles and the hard carbon particles, the rapid charging performance of the lithium ion battery is improved, and meanwhile, relatively high energy density is kept; and the negative pole piece also has relatively good flexibility, so that the problems of breakage and powder falling in the processing process are relieved.

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 lithium ion batteries, and relates to a liquid injection method of a lithium ion battery, in particular to a lithium ion battery electrolyte combination, a secondary liquid injection process and the lithium ion battery. The calculation formula of the mass content (W1) of the vinylene carbonate in the first electrolyte is # imgabs0; the calculation formula of the mass content (W2) of the vinylene carbonate in the second electrolyte is # imgabs1 # imgabs2 #, and W1 is less than W2. According to the invention, the content of vinylene carbonate in the electrolyte injected twice is adjusted according to the proportion of the secondary particles, the content of the negative electrode active material, the interlayer spacing of the graphite particles and the interlayer spacing of the carbon coating layer, so that the performance of the lithium ion battery can be better improved.

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 discloses a preparation method of a graphite composite bipolar plate, which comprises the processes of raw material homogenization, preheating treatment, hot press molding, demolding, stress relief and cutting and trimming, the raw material homogenization and stress relief processes can significantly improve the yield and product quality, and the problems of low yield, poor batch stability and the like in the prior art are solved; meanwhile, conductive fillers such as graphene, carbon fibers, carbon black, carbon nanotubes and metal fibers are introduced, so that a bridging effect among graphite particles is achieved, a conductive path is broken through, contact resistance is reduced, the overall conductivity of the bipolar plate is improved, the mechanical property of the material can be improved, and the service life of the bipolar plate is prolonged. Particularly, the bending strength is obviously improved; in addition, the method is simple in process, flexible to adjust, low in special equipment requirement, low in equipment investment and suitable for popularization.

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 present invention relates to the technical field of electrochemical devices, and provides a lithium ion battery, the lithium ion battery comprises a positive plate, a negative plate, a diaphragm and an electrolyte, the negative plate comprises a negative current collector and a negative active material layer located on at least one side surface of the negative current collector, the negative active material layer comprises a negative active material, and the negative active material layer comprises a positive electrode active material and a negative electrode active material. The negative active material comprises graphite particles; when the lithium ion battery is in a 0% SOC state of charge, the distance between the negative electrode active material layer and the negative electrode current collector is less than 0.5 [mu] m, and the distance between the adjacent graphite particles is less than 2 [mu] m. The lithium ion battery provided by the invention has relatively long charge-discharge cycle life and relatively high energy density.

Embodiments described herein relate to anode particles produced in part from discarded graphite particles, and methods of producing the same. In some aspects, a method of forming carbon-coated anode particles can include mixing a first plurality of particles, a second plurality of particles, and a plurality of graphene particles to form a dry powder, the first plurality of graphite particles including particles rejected from a graphite spheronization process, the second plurality of graphite particles including particles rejected from a graphite micronization process, mixing the dry powder with water and a carbon-containing liquid to form a slurry, spray-drying the slurry to form an agglomerated mix, and heating the agglomerated mix to form carbon-coated anode particles. In some embodiments, the spray-drying includes atomizing the slurry to form droplets. In some embodiments, the spray-drying can include heating the droplets in a heated chamber to form dried particles.

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.

The invention relates to the technical field of graphite shaping, in particular to a smashing and shaping device for cathode graphite, which comprises a cylinder, a vertical cylinder is fixed at the center of the inner side of the cylinder, a plurality of concentrically arranged grinding rings are movably arranged on the outer side of the vertical cylinder, and a supporting ring is fixed on the lower side of each grinding ring. A driving mechanism used for driving the adjacent supporting rings to rotate reversely is arranged at the lower end of the vertical cylinder. The multiple supporting rings and the grinding rings are driven to rotate through the driving mechanism, the spaced grinding rings are driven to rotate through the two first traction wheels and the two second traction wheels correspondingly, so that reverse rotation between the adjacent grinding rings is achieved, meanwhile, the two sliding square rods are driven to move in a reciprocating mode through the telescopic mechanism, and the grinding efficiency is improved. And the multiple pushing plates push the graphite particles back and forth between the upper sides of the adjacent reverse grinding rings, the graphite particles at all positions can be ground more uniformly, and the shaping efficiency is improved.

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.

The invention relates to a refractory castable for a blast furnace tapping main channel. The refractory castable is prepared from the following raw materials in parts by mass: 35-45 parts of compact corundum, 25-35 parts of white corundum, 12-18 parts of silicon carbide, 4-7 parts of alpha-Al2O3 micro powder, 2-5 parts of rho-Al2O3 micro powder, 6-10 parts of modified graphite, 1-5 parts of an antioxidant, 0.1-0.3 part of organic fibers and 0.05-0.2 part of a water reducing agent, the modified graphite is obtained by carrying out interface chemical deposition reaction on graphite oxide to form Mg (OH) 2 / Al (OH) 3 coated graphite particles, then calcining in an inert atmosphere to form MgO / Al2O3 coated graphite particles, and then carrying out surface modification by carboxyl-terminated polyethylene glycol silane. The antioxidant is a compound of magnesium carbide, boron carbide and silicon powder. The refractory castable for the blast furnace tapping main channel has excellent slag corrosion resistance, high temperature resistance and thermal shock resistance.

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.

The invention discloses a preparation method of polylactic acid fibers for medical and sanitary materials, and relates to the technical field of polylactic acid fibers. Nano-crystalline cellulose, nano-graphite particles and polylactic acid are blended and crosslinked, the mechanical property of a matrix is enhanced, the antibacterial property is achieved, fibers are prepared through spinning, supercritical carbon dioxide treatment is conducted for the first time, the nano-graphite particles can play a role of a nucleating agent, polylactic acid is promoted to form fine and uniform crystals, and the mechanical property of the matrix is improved. Carbon dioxide is effectively wrapped in the foaming process, a micropore structure is formed in the fiber, the mechanical property of a matrix is enhanced, then secondary supercritical carbon dioxide treatment is conducted, the nano-silver is loaded into the matrix through supercritical fluid, the antibacterial property and the mechanical property are further improved, then the nano-silver is soaked in a silicate solution, dehydration is conducted, and the nano-silver fiber is obtained. A silica gel layer is formed on the surface of the fiber, so that the mechanical property and the antibacterial property of a matrix are enhanced.

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.

The invention provides a waste lithium battery graphite purification, repair and regeneration method, which comprises the following steps: placing a waste lithium battery negative pole piece in a high-frequency alternating magnetic field and atmospheric plasma coupling field, rapidly heating through the eddy current effect of a copper current collector to form a temperature gradient with a graphite coating, and synchronously cleaning organic matters by adopting air plasma to obtain the graphite purification, repair and regeneration method. The preparation method comprises the following steps of: removing impurities such as amorphous carbon, metal and oxide, an SEI (solid electrolyte interface) membrane and organic matters by using a high-temperature-controlled pyrolysis binder and stripping graphite particles, carrying out shearing homogeneous dispersion, reverse flotation, chelation and oxidation purification synergistic treatment to remove impurities such as amorphous carbon, metal and oxide, the SEI membrane and the organic matters, and carrying out low-pressure degassing on the deeply purified graphite at a room temperature section by using a sectional integrated screw rod, in the medium-temperature section, graphite and micro-liquefied asphalt are kneaded and extruded to be filled in internal holes and surfaces of the graphite, and the asphalt and the graphite are mixed and melted into a whole after high-temperature carbonization, so that the graphite structure is repaired and regenerated. The invention further provides a graphite negative pole piece and a lithium ion battery which are prepared by taking the purified, repaired and regenerated graphite as a negative pole material.

The invention relates to the technical field of lithium ion battery negative electrode materials, in particular to a graphite negative electrode material and a preparation method thereof, a negative electrode plate and a lithium ion battery. The graphite negative electrode material comprises composite particles, the composite particles comprise graphite particles and polymer films coating the surfaces of the graphite particles, and the materials of the polymer films comprise polyolefin and / or polyurethane; the weight loss ratio of a TG curve obtained by carrying out a thermal weight loss test on the graphite negative electrode material in an air atmosphere at 200-600 DEG C is 1%-5%. The surfaces of the graphite particles are coated with a small amount of polyolefin and / or polyurethane, so that the specific surface area can be remarkably reduced, and the compaction density can be improved.

The invention discloses a nodular cast iron graphite particle distribution detection method and system, and the method comprises the following steps: 1) obtaining an original metallographic image of nodular cast iron graphite particles, and converting the original metallographic image into a grayscale image; 2) performing threshold processing on the grayscale image to generate a binary image; 3) extracting an edge in the binarized image by adopting an edge detection algorithm; 4) carrying out closing operation on the edge to form a closed outline; 5) extracting and screening contours, and removing noise and incomplete contours; 6) calculating the centroid of the screened contour; 7) constructing an empirical distribution function; and 8) evaluating the distribution uniformity of the graphite particles. The system comprises an image acquisition module, an image processing module, a calculation module, an inspection module and an output module. Through the automatic process, the efficiency of quality detection of the nodular cast iron material is improved, the subjectivity and errors of manual detection are reduced, and the method has important significance for controlling the mechanical property and toughness of the nodular cast iron material.