1717 results about "Carbon composites" patented technology

The invention relates to a method for preparing a lithium iron phosphate / carbon composite material of a lithium ion battery, which belongs to the technical field of lithium ion batteries. The method for preparing the lithium iron phosphate / carbon composite material of the lithium ion battery comprises the following steps of: 1) preparing a suspending graphene-dispersed aqueous solution system, namely, crushing graphite to 1 to 5 microns, adding the crushed graphite into distilled water or purified water, adding 0.1 to 5 percent of surfactant, heating with stirring the mixed solution to 180 to 250 DEG C in a sealing way, performing stirring for 2 to 6 hours and reducing the temperature; 2) crushing lithium iron phosphate to the particle size of 1 to 5 microns, adding the crushed lithium iron phosphate into the distilled water or the purified water, adding with stirring 0.01 to 1 percent of coupling agent, performing uniform stirring, adding the graphene-dispersed aqueous solution, and performing stirring and filtration; and 3) vacuum-drying solid powder obtained by the filtration, and calcinating the dried solid powder for 2 to 12 hours to obtain the graphene-coated lithium iron phosphate cathode material. The method has the advantages of simple process, high material performance, high conductivity, high bulk density, high compacted density and the like.

The invention provides a low-carbon concrete coarse aggregate close packing combination grading formula and a determination method, and relates to the technical field of building materials, the formula comprises a coarse aggregate skeleton, a fine aggregate, a low-carbon cementing material, water and an admixture, the coarse aggregate skeleton is composed of four different size fractions, and the purpose is to achieve the closest packing to reduce the cement requirement and improve the cement quality. The low-carbon cementing material is composed of cement, a conventional low-carbon mineral admixture and a low-carbon composite mineral admixture, and the low-carbon composite mineral admixture comprises an active component A and a micro-filling component B. The determination method comprises the steps of system characterization and model establishment, slurry skeleton iterative collaborative optimization and formula determination. The porosity is reduced to the maximum extent by optimizing coarse aggregate grading, the cement consumption is greatly reduced, meanwhile, through the synergistic effect of the high-performance, high-proportion and low-carbon admixture, the working performance, physical and mechanical properties and durability of the concrete are ensured, carbon emission and material cost are remarkably reduced, industrial solid waste is effectively utilized, and the economic benefit is increased. And green low-carbon preparation of the concrete is realized.

The invention provides a phenolic resin-based spherical silicon-carbon composite material as well as a preparation method and application thereof, and belongs to the technical field of lithium battery materials. The preparation method comprises the following steps: preparing spherical phenolic resin by adopting a suspension polymerization method, curing to obtain phenolic resin microspheres, preparing porous carbon spheres by taking the phenolic resin microspheres as a carbon precursor in a carbonization and alkali activation manner, carrying out CVD vapor deposition on nano silicon, and carrying out carbon coating to obtain the phenolic resin-based spherical silicon-carbon composite material. The phenolic resin is utilized to form a highly cross-linked network structure after curing, the carbon spheres obtained after carbonization have good mechanical strength and rigidity, the porous structure of the porous carbon spheres provides a volume change buffering structure for nano-silicon, the lithium ion path is shortened, the spherical structure is beneficial to uniform dispersion, nano-silicon particles are prevented from gathering, and the performance of the lithium ion battery is improved. And the porous carbon spheres with high specific surface area can also improve the interface reaction activity, so that the problems of high volume expansion, low conductivity and slow ion diffusivity of silicon are solved.

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly relates to a spinel type metal oxide coated hard carbon composite material based on a lattice matching mechanism, and a gradient doping preparation method of the spinel type metal oxide coated hard carbon composite material can overcome the defects that a hard carbon material is low in initial coulombic efficiency (about 50%), low in lithium ion transmission rate and poor in rate capability. According to the invention, magnesium salt, aluminum salt, copper salt and other metal salts are mixed with hard carbon, a precipitant is added, and a hydrothermal method is combined with a calcination process to obtain the core-shell structure composite material with hard carbon coated with a spinel structure. The technology has the following three obvious advantages: (1) lattice adaptive design of the spar type metal oxide and the hard carbon, (2) molybdenum-copper gradient doping repair of the SEI film, and (3) stable circulation of more than 5000 times at the capacity of 350mAh / g.

The invention belongs to the technical field of electrochemical energy storage, and discloses a composite bipolar plate for a zinc-bromine flow battery and a preparation method thereof.The preparation method comprises the steps that carbon fibers, ketjen black and graphene dispersion liquid are stirred to be uniform, and a conductive carbon composite material is obtained; a binder, a dispersing agent and the conductive carbon composite material are subjected to ball milling, and a bipolar plate prefabricated material is obtained; carrying out melt blending on the bipolar plate prefabricated material, and extruding to obtain a substrate; and spraying the nitrogen-doped porous carbon material on the surface of a substrate, and performing hot pressing. The graphene, the carbon fibers and the ketjen black are stirred and compounded, the carbon fibers and the ketjen black enter the space between graphene sheet layers, and the ketjen black is attached to the surfaces of the carbon fibers and the graphene, so that the structure not only can prevent the graphene from generating a re-stacking effect in the mixing process, but also can form a'point-line-surface 'ternary interpenetrating high-conductivity network, so that the conductivity of the graphene is improved. According to the preparation method disclosed by the invention, the deposition uniformity of zinc is improved, so that the voltage efficiency and the cycling stability of the battery are improved.

The invention provides a silicon-carbon negative electrode material and a preparation method thereof, a negative electrode and a lithium ion battery, and particularly relates to the technical field of negative electrode materials, the silicon-carbon negative electrode material comprises a porous carbon substrate, a silicon-containing substance and a phosphorosilicate glass coating layer, the silicon-containing substance is loaded in pore channels of the porous carbon substrate and forms a silicon-carbon compound, and the phosphorosilicate glass coating layer is coated with the silicon-carbon compound. The surface of the silicon-carbon compound is coated with the phosphorosilicate glass coating layer, phosphorus elements entering the silicon-carbon compound through thermal diffusion doping are arranged in the silicon-carbon compound, and a phosphorus-doped region is formed. The phosphorosilicate glass coating layer improves the strength of the silicon-carbon negative electrode and inhibits the volume expansion of the silicon-carbon negative electrode material. Meanwhile, the electrical property of the silicon-carbon negative electrode is improved through phosphorus doping, the structural stability and the electrochemical performance of the silicon-carbon negative electrode are improved, and the cycle life is prolonged.

The invention discloses a high-strength heat-insulation aerogel structure with a dual multi-scale design and a preparation method thereof, relates to the technical field of thermal protection of spacecrafts, and in particular relates to the high-strength heat-insulation aerogel structure with the dual multi-scale design and the preparation method thereof. The invention aims to solve the problems of insufficient structural rigidity and poorer thermal protection property and thermal stability of the traditional spacecraft surface aerogel structure under the conditions of extreme high temperature and mechanical load. The structure is composed of an upper carbon-carbon composite material plate, a lower carbon-carbon composite material plate, an alloy skeleton and a filler. The method comprises the following steps: 1, preparing a multi-scale C / C composite material; 2, designing and preparing a titanium alloy honeycomb framework; 3, proportioning the multi-scale aerogel; 4, in-mold in-situ gelation; 5, drying and heat treatment; and 6, assembling and solidifying. The porosity of the aerogel is 85-98%, the structure has high rigidity and thermal protection performance, and the aerogel is applied to the field of aerospace thermal protection.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a preparation method of a graded ordered silicon-carbon negative electrode material for a lithium ion battery, which comprises the following steps: (S1) mixing phenolic resin and a template agent, calcining, and etching to obtain porous carbon containing macropores; (S2) carrying out cracking and carbon coating on the silicon source gas to obtain nano crystalline silicon containing a carbon coating layer; (S3) mixing the porous carbon with the nano crystalline silicon containing the carbon coating layer, and then carrying out ultrasonic vibration, so that macropores of the porous carbon are filled with the nano crystalline silicon to obtain a silicon-carbon composite material I; (S4) treating the silicon-carbon composite material I by using a carbon-containing sealing agent, and then activating to obtain a silicon-carbon composite material II; and (S5) carrying out vapor phase silicon deposition on the silicon-carbon composite material II to fill the amorphous silicon in the pores of the porous carbon, and then carrying out carbon coating to obtain the graded ordered silicon-carbon negative electrode material. The silicon-carbon negative electrode material prepared by the invention is of a composite structure in which crystalline silicon and amorphous silicon are spatially and orderly distributed, so that the structural stability and the uniform distribution of silicon are realized.

The invention discloses a negative electrode active material and a preparation method thereof, a negative electrode pole piece and a secondary battery, the negative electrode active material provided by the invention comprises a silicon-carbon composite material and an aluminum oxide layer coated on the surface of the silicon-carbon composite material, and the silicon-carbon composite material is a composite material of nitrogen-fluorine co-doped porous carbon and nano silicon particles. By optimizing and regulating the porosity and pore size distribution of the porous carbon, the ion transmission kinetics and the structural stability are improved, and the problems of poor rate capability, short cycle life and the like caused by single pore size of the traditional porous carbon are solved. By adopting the nitrogen and fluorine co-doped porous carbon skeleton, the conductivity of the electrode material is enhanced, and the cycling stability of the battery is improved. The nano silicon component uniformly deposited through a chemical vapor phase method provides high specific capacity, the aluminum oxide coating layer can effectively inhibit the decomposition reaction of the solid electrolyte, and the long-term stability and cycle performance of the electrode structure are jointly guaranteed through the dual effects.

The invention discloses an atomic layer deposition silicon-carbon composite material, a preparation method and application thereof, a core-shell coating structure composed of an inner core and an outer shell is adopted, the inner core is a multi-element doped silicon-carbon material, and the outer shell is a solid electrolyte composite layer; the mass ratio of the inner core to the shell is (80-95): (5-20); the solid electrolyte is deposited on the surface of the specific silicon carbon material through an atomic vapor deposition method, so that the expansion is reduced, and the cycle performance of the battery is improved.

The invention provides an efficient chloramphenicol degradation method based on Co-Cu-carbon composite nano-catalyst activated peroxymonosulfate, which comprises the following steps: regulating the Co / Cu molar ratio in a bimetal organic framework precursor, and performing pyrolysis to prepare the Co-Cu-carbon composite catalyst with an optimized pore structure, graphitization degree and metal dispersity; peroxymonosulfate is activated by utilizing the synergistic effect of Co / Co and Cu / Cu redox pairs to generate sulfate free radicals, hydroxyl free radicals, singlet oxygen and superoxide free radicals, and direct oxidative degradation of chloramphenicol is promoted by taking a catalyst as an electron transfer bridge; the method realizes rapid and efficient removal of chloramphenicol, high mineralization rate, excellent cycle stability and strong anti-interference capability, and solves the technical problems of low removal efficiency, high cost and easy secondary pollution in the prior art.

The invention discloses a preparation method of a high-conductivity and low-thermal-conductivity carbon-carbon composite material electrode, and relates to the technical field of electrode preparation, the preparation method comprises the following steps: mixing nano carbon spheres, an organic binder and a solvent to obtain a mixed slurry, respectively coating the mixed slurry on a PAN-based carbon fiber web and pitch-based carbon fiber non-woven cloth, and drying to obtain the high-conductivity and low-thermal-conductivity carbon-carbon composite material electrode. Then preparing a preform by alternately laying and needling the PAN-based carbon fiber web coated with the mixed slurry and pitch-based carbon fiber non-woven cloth, pretreating the preform by adopting a chemical vapor deposition technology to obtain an intermediate I, and treating the intermediate I in a pressure impregnation tank and a carbonization and graphitization furnace to obtain an intermediate II; and carrying out pressure impregnation-carbonization treatment on the intermediate II to obtain the carbon / carbon composite material. According to the preparation method of the high-conductivity and low-heat-conductivity carbon-carbon composite material electrode, the material has high conductivity and low heat conductivity, a carrier is provided for precise heat management under specific conditions in a high-temperature furnace, and the energy consumption of equipment is reduced.

The invention discloses a biomass-based hard carbon composite material quantitatively prepared based on a hard carbon pore volume and a method thereof, a negative electrode material and a battery. The method provided by the invention comprises the following steps: firstly, uniformly dispersing a pore-forming agent in biomass powder, pre-carbonizing, and washing to obtain a porous carbon matrix; according to the steps, pore forming is completed while pre-carbonization is completed, the porous carbon matrix with a certain pore volume is prepared, the dosage of the soft carbon precursor is designed based on the total pore volume in the subsequent steps, quantification and rationalization of the dosage of the soft carbon precursor can be achieved, the obtained product is good in performance consistency, and industrial production can be achieved. And the problem that subsequent soft carbon raw materials cannot be scientifically matched due to diversity of raw materials of biomass with different sources can also be avoided. Besides, by utilizing the chemical cross-linking reaction of asphalt and biomass carbon, not only is the carbon residue rate improved, but also a unique structure rich in closed pores and ultra-micropores is constructed, and the problems of low initial coulombic efficiency and insufficient platform capacity of traditional hard carbon are effectively solved.

The invention discloses a graded graphitization degree porous carbon material, a preparation method and application, the graded graphitization degree porous carbon material comprises an inner layer low graphitization area, a middle layer transition area and an outer layer high graphitization area from inside to outside, the preparation method comprises the following steps: S1, carbonizing a carbon source to obtain a carbon precursor, and activating the carbon precursor to obtain activated carbon; a porous carbon skeleton is obtained; and S2, under the atmosphere of H2 / Ar mixed gas, carrying out high-temperature treatment on the porous carbon skeleton to obtain the graded graphitization degree porous carbon material. The invention discloses a graded graphitization degree porous carbon material and a silicon-carbon composite negative electrode material prepared by taking the graded graphitization degree porous carbon material as a substrate, and through spatial design of the graphitization degree of the porous carbon substrate, the silicon-carbon performance is synergistically improved in the atomic scale (interlayer spacing regulation and control) and the microscale (pore structure optimization); a battery assembled by the silicon-carbon composite negative electrode material has excellent cycling stability and rate capability, and also has relatively high initial specific capacity and initial coulombic efficiency.

Silicon-carbon composites obtainable by a process comprising the following steps: Step 1: Provision of one or more porous carbon particles, wherein the porous carbon particles (i) covalent organic framework compounds (COFs) are, (ii) a mean electrical particle resistance of at least 0.5 MΩ, (iii) a reversible delthiation capacity β of not more than 100 mAh / g and (iv) exhibit a mass loss of no more than 10 wt.% up to 380°C, Step 2: Thermal deposition of silicon from one or more gaseous silicon precursor(s) in the pores and / or on the surface of the porous carbon particles and, if applicable, Step 3: Deposition of additional carbon in the pores and / or on the outer surface of the silicon-carbon composites if the silicon-carbon composites after Step 2 have a specific surface area above 50 m²2 / g, wherein the silicon-carbon composites after step 2 and, if applicable, step 3 a) a specific surface area of ​​at most 50 m² 2 / g and b) have an average electrical particle resistance of at least 0.5 MΩ. Furthermore, a method for producing the silicon-carbon composites according to the invention, their use as active materials in anodes for lithium-ion batteries, anodes containing these silicon-carbon composites, and lithium-ion batteries comprising anodes containing these silicon-carbon composites are the subject of the present invention.

The invention provides a self-healing silicon-carbon composite negative electrode material and a preparation method and application thereof. The self-healing silicon-carbon composite negative electrode material comprises a core material formed by silicon-carbon composite particles and a shell layer formed by a self-healing solid electrolyte coating layer, the self-healing solid electrolyte coating layer is a polymer network containing dynamic covalent bonds, and lithium salt is doped in the polymer network. According to the invention, through reversible fracture and recombination of dynamic covalent bonds, microcracks generated by volume expansion of silicon are automatically repaired in situ.

The invention relates to the technical field of battery negative electrode materials, in particular to irregular spherical porous carbon and a preparation method and application thereof, and a silicon-carbon composite material and a preparation method and application thereof. The liquid phenolic resin is emulsified, compounded, cross-linked and cured under the condition of an oil-soluble and water-soluble compound emulsifier, meanwhile, the shape of the obtained resin is changed in an ultrasonic-assisted mode under the combined action of ultrasonic disturbance and different interfacial tensions, spherical resin is adjusted into irregular spherical resin, and the spherical resin is prepared into the irregular spherical resin. And performing pyrolysis and gas activation to obtain the irregular porous spherical carbon. Compared with spherical carbon, the irregular spherical carbon prepared by the invention has the advantages that on the premise of keeping the strength of the spherical carbon, the irregular spherical carbon can increase the contact area between carbon particles and a binder, and the carbon particles and the binder are not easy to separate, so that the cycling stability of a battery (especially a lithium ion battery) is improved.

The invention relates to the technical field of lithium battery negative electrode materials, and discloses a preparation method of a lithium battery silicon-carbon composite negative electrode material with high cycle stability, and the preparation method comprises the following steps: carrying out magnesiothermic reduction and acid etching on micron silicon powder and magnesium powder to prepare porous silicon particles; growing carbon nanotubes on the surfaces of the porous silicon particles and in pore channels in situ to construct a three-dimensional conductive network; styrene butadiene rubber and glucose are adopted as a composite carbon source to coat the product, and a composite carbon layer is formed through drying and gradient carbonization; and finally grinding and sieving the carbonized product. According to the preparation method disclosed by the invention, pores are constructed in micron silicon, and the micron silicon is externally coated with the composite carbon layer with flexibility and rigidity, so that the volume expansion of silicon is effectively buffered; the in-situ grown carbon nanotube network provides a stable electron conduction path; the micron-sized substrate reduces the specific surface area of the material and improves the first coulombic efficiency. Therefore, the prepared negative electrode material has high cycling stability and excellent rate capability.

The invention discloses a silicon-carbon composite material and a preparation method thereof, a negative plate and a battery, and relates to the technical field of batteries, the silicon-carbon composite material comprises a silicon-carbon core body and a BN / MXene / Li composite layer which are arranged in sequence from inside to outside, and the surface of the silicon-carbon core body is at least partially coated with the BN / MXene / Li composite layer. The silicon-carbon composite material provided by the invention has high cycle performance and high initial coulombic efficiency of a battery.

The invention discloses a device and process for treating pharmaceutical wastewater through an internal electrolysis method. The device comprises a pretreatment unit, an internal electrolysis reaction unit, a precipitation separation unit, a pH adjusting unit and a control system which are sequentially connected. The internal electrolytic reaction unit comprises a reaction tower body, the top of the reaction tower body is provided with a water inlet, and the bottom is provided with a water outlet; a supporting layer, an iron-carbon micro-electrolysis filler layer, a catalytic oxidation layer and a biological membrane layer are sequentially arranged in the reaction tower body from bottom to top, the iron-carbon micro-electrolysis filler layer comprises an iron-carbon composite filler, and the mass ratio of iron to carbon in the iron-carbon composite filler is (1: 1)-(3: 1). The internal electrolysis reaction unit with a multi-level filling structure is adopted, iron-carbon micro-electrolysis, catalytic oxidation and biodegradation are organically combined to form a synergistic effect, the removal efficiency of refractory organics in the pharmaceutical wastewater is remarkably improved, and the COD removal rate can reach 80% or above.

The invention provides a solar cell and a preparation method thereof, and a photovoltaic module, the solar cell comprises a substrate, and a first transmission layer, a perovskite layer, a second transmission layer and a silver-carbon composite electrode which are sequentially arranged on the substrate, the silver-carbon composite electrode is located on the surface of the second transmission layer, and the silver-carbon composite electrode comprises a first electrode layer and a second electrode layer, the first electrode layer comprises a conductive polymer and a carbon material, the second electrode layer comprises silver, and the thickness of the second electrode layer is 10-20 nm. The solar cell provided by the invention has higher photoelectric conversion performance and lower manufacturing cost.

The invention discloses a porous silicon-carbon composite negative electrode material, a one-step preparation method, a lithium ion battery and application, and belongs to the technical field of lithium ion battery materials, the method comprises the following steps: mixing a silicon source, magnesium powder, a carbon source and a soluble pore forming agent to obtain mixed powder; performing high-energy mechanical ball milling on the mixed powder in an inert atmosphere, and performing acid pickling, high-temperature carbonization treatment, cooling, water washing, suction filtration and drying to obtain the porous silicon-carbon composite negative electrode material; the porous silicon-carbon composite negative electrode material comprises a porous shell formed by amorphous porous carbon and a porous core formed by silicon nanoparticles embedded in the porous shell, the mechanical collision energy generated in the high-energy mechanical ball milling process triggers the low-temperature magnesiothermic reduction reaction between the silicon source and the magnesium powder, the carbon source is attached to the surfaces of silicon particles while the silicon particles are generated, and silicon synthesis, carbon coating and pore forming are synchronously achieved. The silicon-based negative electrode has the advantages of high initial coulombic efficiency, high specific capacity, excellent cycle stability and rate capability, and effectively solves the problems of volume expansion and large-scale preparation of the silicon-based negative electrode.

The invention discloses a photovoltaic waste silicon and recycled carbon composite granulation coating process, and relates to the field of new energy materials. According to the method, high-purity silicon waste sheets recovered from retired photovoltaic modules and carbon materials recovered from electronic wastes are subjected to composite granulation, and a carbon coating layer is formed through heat treatment. The preparation method specifically comprises the steps of raw material pretreatment, mixing, granulation forming, coating carbonization, post-treatment and the like, the prepared silicon-carbon composite particles have good conductivity and structural stability and can be used for lithium ion battery negative electrode materials, and efficient recycling of resources and environment-friendly production are achieved.

The application provides a preparation method of a self-coiled structure molybdenum disulfide / nitrogen-doped porous carbon composite material, a product and application, high-content nitrogen-doped porous carbon material is synthesized by inducing dicyandiamide molecules to undergo a supramolecular self-assembly process, and on this basis, a hydrothermal reaction is carried out to coat molybdenum sulfide sheet layer material on the surface, and finally, a self-heating coiling treatment is carried out to form a carbon-based electrocatalyst of the self-coiled structure molybdenum disulfide / nitrogen-doped porous carbon. Compared with a high specific surface area carbon-based catalyst, high doping concentration of nitrogen atoms can provide more electron-rich properties to facilitate the adsorption of substances, and the self-coiled carbon-based material can exhibit very excellent electrochemical performance, especially in the aspect of electrochemical hydrogen production. The preparation method is simple in operation, low in preparation cost and suitable for large-scale production.

The invention provides a preparation method of a carbon composite current collector without a macromolecular adhesive. The method ingeniously utilizes charge transfer and pi-pi interaction between the conductive carbon material and the auxiliary agent to realize infiltration of the conductive carbon material, and assists uniform mixing of the conductive carbon material to finally form the paste slurry. And after the pasty slurry is pressed and washed, the carbon composite current collector with uniform thickness and good conductivity is constructed on the surface of a substrate. In the carbon film, the carbon nanotubes with the one-dimensional structure construct a conductive network, the graphite powder or graphene with the two-dimensional structure plays a role in bonding the carbon tubes under high voltage by utilizing the flexibility of the graphite powder or graphene and through pi-pi interaction, the contact resistance between the carbon tubes is reduced, and the mechanical property of the composite current collector is enhanced. The preparation method is simple in process and low in cost, the prepared carbon composite current collector is outstanding in chloride ion corrosion resistance, and powerful guarantee is provided for performance improvement and long-term stable operation of a chloride ion-containing water system energy storage device.

The invention discloses a preparation method of a high-density carbon-carbon composite material, which comprises the following steps: soaking a needled prefabricated body in a resin mixed solution, vacuumizing and dipping, drying in a drying oven, then putting into a mold, carrying out hot-pressing curing molding, and carbonizing to obtain the high-density carbon-carbon composite material. According to the preparation method, the carbon-carbon composite material with the density larger than 1.2 g / cm < 3 > can be obtained through one-time dipping and one-time hot pressing, the production period is short, energy consumption is low, the production cost is remarkably reduced, and the carbon-ceramic composite material with the density larger than 1.2 g / cm < 3 > can be obtained through one-time dipping and one-time hot pressing. And the prepared carbon-carbon composite material can achieve a high-density effect when the density is low, and has the characteristics of good air tightness, difficulty in deformation at high temperature and the like.

The invention discloses an electrode health diagnosis method for a silicon-carbon negative electrode battery with a self-adaptive voltage range, and relates to the technical field of battery control, and the method comprises the steps: obtaining a quasi-static open-circuit voltage discharge curve according to a low-rate discharge test of the silicon-carbon negative electrode battery in an aging process, and measuring the total battery capacity; analyzing and extracting the silicon content in the battery; reconstructing a silicon-carbon composite electrode curve according to the silicon content, and performing inversion calculation of a voltage reconstruction model to obtain electrode parameters; the method comprises the following steps: acquiring charging fragment data of a silicon-carbon negative electrode battery in a circulation process, extracting charging time sequence characteristics based on equal interval voltage alignment and relaxation voltage characteristics after full charge according to the charging fragment data, and constructing a corresponding binary mask array; and constructing an estimation model, and performing supervised learning to obtain a trained estimation model for performing diagnosis of the electrode health parameters according to the charging fragment data, thereby effectively improving adaptability and accuracy during electrode health diagnosis.

The present invention relates to a preparation method for a silicon-carbon composite negative electrode material, comprising the following steps: (P1) co-polymerization: co-dissolving an unsaturated organic acid, an acrylate monomer and an acrylamide monomer in water at a specific ratio, and co-polymerizing same under the action of a sacrificial agent of a saturated organic acid and an initiator to obtain a suspension containing an acrylic copolymer; (P2) alkali treatment: performing an alkali treatment and filtration on the suspension to obtain copolymer particles; (P3) in-situ polymerization: performing in-situ polymerization of phenolic aldehyde on the surfaces of the copolymer particles to obtain a composite resin of a phenolic aldehyde-coated acrylic copolymer; (P4) heat treatment: performing a heat treatment on the composite resin in an oxidizing gas atmosphere to obtain porous carbon; and (P5) performing silicon deposition and carbon coating on the porous carbon to obtain the silicon-carbon composite negative electrode material. When the silicon-carbon composite negative electrode material prepared in the present invention is used in a lithium battery, the volume expansion of silicon can be effectively relieved, and the cycling performance and charge-discharge capacity of a lithium-ion battery are improved.

The invention discloses a ceramic component gradient modified C / C-SiC-ZrC composite material and a preparation method thereof, and belongs to the technical field of carbon / carbon composite material matrix modification preparation, a carbon fiber preform and a heating element are placed in chemical liquid phase vaporization deposition equipment, a precursor solution is added until the carbon fiber preform is fully soaked, and a ceramic component gradient modified C / C-SiC-ZrC composite material is obtained; and carrying out chemical liquid phase vaporization deposition reaction to obtain the low-density C / C composite material with porosity in unidirectional gradient distribution. And putting the mixture into a graphite crucible with a carbon-rich area facing downwards and a carbon-less area facing upwards, completely putting the graphite crucible into the ceramic powder for modification, reacting and infiltrating, and cooling to room temperature to obtain the C / C-SiC-ZrC composite material with the gradient modified ceramic components. The end with high ceramic content endows the material with a high-temperature thermal protection function, the end with high pyrolytic carbon content can effectively conduct heat generated in a ceramic-rich area, and the end with low ceramic content can effectively conduct heat generated in a ceramic-rich area. Due to the gradient design from the ceramic-rich area to the carbon-rich area, the material has high-temperature oxidation resistance and ablation resistance and is light, and lightweight design of an aerospace thermal protection structure is facilitated.

The invention discloses a high-magnification low-expansion modified silicon-carbon composite material and a preparation method and application thereof, the modified silicon-carbon composite material is of a particle structure and comprises a silicon-carbon material serving as an inner core and a fluorine-containing conductive polymer layer coating the surface of the silicon-carbon material; the silicon-carbon material is obtained by coating the surfaces of silicon particles with carbon layers; the fluorine-containing conductive polymer layer is obtained by initiating polymerization of a first monomer and a second monomer, and the first monomer is a fluorine-containing polymer monomer. The preparation method comprises the following steps: putting the silicon-carbon material, a first monomer and a second monomer into a hydrothermal reaction kettle, adding a mixed solvent of water and ethanol, heating while stirring, adding an initiator after heating to a target temperature, preserving heat, reacting, cooling, carrying out suction filtration, washing with water, and drying to obtain the fluoro-coated silicon-carbon material, namely the modified silicon-carbon composite material. According to the application, the modified silicon-carbon composite material serves as a negative electrode active component and is mixed with a conductive agent, a binding agent and a dispersing agent, so that the negative electrode coating slurry for preparing the negative electrode plate of the lithium ion battery is formed.