1386 results about "Amorphous carbon" patented technology

The invention relates to the technical field of batteries, in particular to a silicon-carbon negative electrode material, a preparation method thereof and a lithium ion battery. The invention provides a silicon-carbon negative electrode material. The silicon-carbon negative electrode material comprises silicon nanoparticles, a porous carbon skeleton, an amorphous carbon layer and a carbon material array structure, pores of the porous carbon skeleton are filled with the silicon nanoparticles; the amorphous carbon layer is coated on the surface of the porous carbon skeleton; the carbon material array structure vertically grows on the surface of the amorphous carbon layer; the carbon material array structure comprises a carbon nanotube array and / or a graphene array. According to the silicon-carbon negative electrode material disclosed by the invention, the compressive strength and the conductivity of the silicon-carbon negative electrode material are improved by vertically growing the carbon nanotube array and / or the graphene array on the surface; therefore, the cycle performance and the rate capability are improved, and the cycle expansion rate is reduced.

The invention discloses a LiAlO2 fast ion conductor coated silicon-carbon composite material as well as a preparation method and application thereof, and belongs to the technical field of lithium ion battery materials. The LiAlO2 fast ion conductor coated silicon carbon composite material has a core-shell structure; an inner core of the composite material is a silicon-carbon composite material, the silicon-carbon composite material is formed by coating a three-dimensional carbon material with an amorphous carbon layer and loading a nano silicon compound, a shell of the composite material is a LiAlO2 fast ion conductor layer, and the silicon-carbon composite material with a three-dimensional network structure is constructed, and the surface of the silicon-carbon composite material is coated with the LiAlO2 fast ion conductor layer, so that the composite material is obtained. According to the present invention, with the LiAlO2, the volume expansion of the nanometer silicon during the charge-discharge process can be effectively relieved, the stability of the silicon-carbon composite material structure can be improved so as to significantly improve the cycle performance of the battery, and the LiAlO2 can provide the rapid channel for the transmission of the lithium ion during the charge-discharge process so as to improve the rate performance of the battery;

The invention relates to the technical field of lithium ion batteries, and provides a negative plate and a lithium ion battery. The negative plate comprises a negative current collector and a negative active material layer arranged on at least one side surface of the negative current collector; the negative electrode active material layer comprises a first negative electrode active material layer and a second negative electrode active material layer, and the second negative electrode active material layer is arranged between the negative electrode current collector and the first negative electrode active material layer; the first negative electrode active material layer comprises an amorphous carbon coated graphite material, and the second negative electrode active material layer comprises a graphite material; the Dv50 of the amorphous carbon coated graphite material is recorded as P1 [mu] m, the Dv50 of the graphite material is recorded as P2 [mu] m, and P1 and P2 satisfy: P1gt; p2. The negative plate adopts a double-layer coating design to form the negative plate of which the surface layer has quick charge and the bottom layer has high energy density, so that the negative plate has both high energy density and quick charge performance.

The invention discloses a graphite composite material as well as a preparation method and application thereof, and belongs to the technical field of preparation of negative electrode materials. The graphite composite material has a core-shell structure, and the core of the core-shell structure comprises magnetic metal oxide doped porous graphite; and the shell of the core-shell structure comprises a carbon nanotube, a lithium supplement agent and amorphous carbon. The specific capacity is improved by doping the magnetic oxide in the porous graphite, and the carbon nanotube lithium supplement agent amorphous carbon is coated on the porous graphite, so that the energy density and the fast charging performance of the battery are improved.

The invention belongs to the field of flow energy storage battery materials, and particularly relates to a multi-dimensional conductive material, a preparation method thereof and application of the multi-dimensional conductive material in an all-vanadium flow battery. Graphite and multi-walled carbon nanotubes are bonded together by adopting a biomass precursor, a carbon base of biomass is converted into graphitized carbon nanotubes through step-by-step pyrolysis, amorphous carbon in the graphite and the original carbon nanotubes is further graphitized, and finally the multi-dimensional conductive material with the carbon nanotubes inserted on a graphite matrix is formed. The multidimensional characteristic of the surface of the multidimensional conductive material is beneficial to formation of a longitudinal conductive path of the bipolar plate and reduction of vertical body resistance of the bipolar plate, and is also beneficial to wetting of epoxy resin among conductive particles and mechanical interlocking of molecular chains of the epoxy resin, so that the mechanical strength of the bipolar plate is improved, the use performance of the bipolar plate is effectively enhanced, and the service life of the bipolar plate is prolonged. The requirement of long-time operation of the flow battery is met, the material cost of the flow battery is relatively reduced, the industrialization of the bipolar plate is powerfully promoted, and the application value is very good.

The invention discloses a calcining carbon removal-supercritical expansion stripping method for regenerating graphene from graphite of a waste lithium battery, and belongs to the field of lithium battery recovery and nano material preparation. Comprising the following steps: treating the waste lithium battery to obtain waste lithium battery positive and negative electrode mixed powder, and then roasting to obtain battery powder; leaching the battery powder in a nitric acid solution to obtain purified graphite slag; the method comprises the following steps: mixing graphite slag with supercritical gas fluid, treating, quickly releasing pressure to normal pressure, and separating to obtain graphene. According to the method, on the basis of interlayer structure characteristics of the waste graphite negative electrode, organic matters and amorphous carbon are removed through multi-stage calcination, a supercritical N2 / CO2 mixed fluid permeation and pressure relief expansion synergistic stripping technology is combined, and low-damage dissociation is achieved through graphite microcracks. According to the method, physical stripping and liquid nitrogen shock cooling strengthening are coupled, and the obtained graphene sheet layer is high in integrity and few in structural defect and can be directly used for manufacturing conductive composite materials and energy storage devices.

The invention provides a sphere-like silicon-carbon negative electrode material and a preparation method and application thereof, and particularly relates to the technical field of negative electrode materials, the negative electrode material comprises a sphere-like porous carbon skeleton, silicon nanoparticles distributed in the sphere-like porous carbon skeleton, and an amorphous carbon layer coating the surface of the sphere-like porous carbon skeleton, the particle appearance of the sphere-like porous carbon skeleton is of a round irregular or asymmetric polyhedral structure and comprises one or more of a potato shape, an ellipse shape, an olive shape, a long strip shape and a pomegranate shape, the particle of the sphere-like porous carbon skeleton is provided with a plurality of asymmetric faces, fillets are formed between the faces, and the radius of the fillets does not exceed 20 microns. The problem of structural damage of the material under the action of external force such as rolling can be effectively relieved, good mechanical stability is kept, excellent bonding performance can be achieved in the electrode coating process, the ion transmission path of the material is improved, and the electronic conductivity and the lithium ion diffusion performance are improved.

The invention discloses a lithium manganese iron phosphate positive electrode material coated with a carbon layer based on a CVD (chemical vapor deposition) method and a preparation method, the preparation method comprises the following steps: forming a uniform carbon coating layer on a lithium manganese iron phosphate precursor based on a CVD coating process, mixing the lithium manganese iron phosphate precursor with the uniform carbon coating layer and a lithium salt, and carrying out co-sintering, and the lithium salt can permeate through the carbon layer to form a lithium-doped uniform carbon coating layer. According to the method, the coating effect is improved, the problem that uniform coating cannot be formed on the surface of the precursor in a traditional carbon coating process is effectively solved, precipitation of trivalent manganese ions at a high temperature can be slowed down, the problem that the capacity exertion is reduced due to the fact that an amorphous carbon layer formed by a CVD cracking coating process affects lithium ion deintercalation is solved, and the performance of the lithium ion battery is improved. The safety and the service life of the battery are improved.

The invention discloses a high-conductivity carbon-coated lithium iron phosphate positive electrode material and a preparation method thereof, and relates to the technical field of lithium iron phosphate positive electrode materials, the high-conductivity carbon-coated lithium iron phosphate positive electrode material comprises a spherical lithium iron phosphate matrix, modified lithium niobium vanadate uniformly coating the exterior of the nanoscale spherical lithium iron phosphate matrix, and a composite carbon layer uniformly coating the exterior of the modified lithium niobium vanadate; wherein the spherical lithium iron phosphate matrix has a smaller specific surface area, so that the reduction of side reaction is facilitated, and the interface impedance can be reduced; the modified lithium niobium vanadate can improve the electronic conductivity of the positive electrode material and the diffusion rate of lithium ions; an organic carbon source in the outermost composite carbon layer is carbonized to form a continuous amorphous carbon layer which uniformly coats the surfaces of the particles, so that a basic electron channel is provided, and side reaction of an electrolyte is inhibited; the inorganic carbon source constructs a three-dimensional conductive skeleton, and a long-range conductive network is formed through the bridging effect of nanowires / sheets, so that the interface contact resistance is reduced, and the conductivity of the positive electrode material is improved.

The invention relates to the technical field of lithium ion batteries, and provides a lithium ion battery, which comprises a negative plate and an electrolyte, the negative plate comprises a negative active material, the negative active material comprises a graphite matrix and a coating layer, and the coating layer comprises an amorphous carbon material; the electrolyte comprises a carbonic ester additive and a chalcogenide additive; based on the total mass of the electrolyte, the mass ratio of the carbonic ester additive is 0.01%-8%, and the mass ratio of the sulfur additive is 0.01%-3%; the mass ratio of the carbonic ester additive to the sulfur additive is 0.3-300. In the lithium ion battery, the negative electrode active material used by the negative electrode is the graphite matrix surface coated amorphous carbon material, so that the low-temperature charging performance of the battery can be improved. Meanwhile, the carbonic ester additive and the sulfur additive are added into the electrolyte, so that the reaction activity of the negative electrode active material can be reduced, side reactions are reduced, the high-temperature performance of the battery is improved, and the battery has high and low temperature performance.

The invention discloses a silicon-carbon material as well as a preparation method and application thereof. The silicon-carbon material comprises nitrogen-doped porous carbon and an amorphous carbon layer coating the nitrogen-doped porous carbon, and pores of the nitrogen-doped porous carbon are filled with boron-doped nano silicon. The nitrogen-doped porous carbon improves the affinity of silane gas while improving the electron conductivity, a high-conductivity and high-density silicon-carbon composite structure is realized, the boron-doped nano silicon and the nitrogen-doped porous carbon form a nano heterojunction site, and the migration rate of lithium ions is improved, so that electrochemical reaction kinetics is improved, and the electrochemical performance of the lithium ion battery is improved. The material has the advantages of high rate and long cycle performance.

Systems or techniques are provided for facilitating improved digital twin calibration for scientific instruments. In various embodiments, a system can synchronize, via execution of a state-wide Bayesian filter, a parametric state of a digital twin with a physical state of a scientific instrument. In various instances, the state-wide Bayesian filter can comprise a set of calibration iterations, each of which can comprise a Bayesian update to an entirety of the parametric state based on an iteration-common observable that is exhibitable by the scientific instrument and simulatable by the digital twin. In various cases, the scientific instrument can be a charged-particle microscope, the parametric state of the digital twin can be an aberration coefficient vector of the charged-particle microscope, and the iteration-common observable can be a Fourier transform of a convergent beam electron diffraction pattern of an amorphous carbon specimen captured by the charged-particle microscope.

The invention discloses a high-initial-efficiency fast-charge graphite composite material and a preparation method thereof, the composite material is of a core-shell structure, the core is graphite, and the shell is lithium sulfonate / lithium molybdate and an amorphous carbon coating layer thereof; the mass ratio of the shell is 5-15 wt% according to the mass ratio of the composite material being 100%. The preparation method comprises the following steps: adding a molybdenum compound into a solvent to prepare a solution, adding graphite oxide, an inorganic lithium salt and a carbon nanotube conductive solution, reacting for 2-12 hours at the temperature of 50-120 DEG C, filtering, carbonizing filter residues to obtain a lithium molybdate conductive agent coated graphite material, and depositing a lithium sulfonate derivative on the surface of the lithium molybdate conductive agent coated graphite material by an atomization method to obtain the lithium molybdate conductive agent coated graphite material. The electron and ion conductivity of the material can be improved, and the rate and the first efficiency of the material can be improved.

The invention relates to the technical field of electrode materials, and discloses a preparation method of a lithium iron manganese phosphate material and a lithium ion battery. The lithium iron manganese phosphate material is prepared by the following steps: performing in-situ growth in a cavity of polyethylene glycol-sucrose hybrid aerogel with a three-dimensional porous network structure to form a manganese iron phosphate precursor; the hybrid aerogel can control excessive agglomeration and disordered growth of ferromanganese phosphate precursor particles and avoid particle agglomeration, so that the finally formed lithium ferromanganese phosphate material particles are finer and more uniformly distributed, and an amorphous carbon-aluminum layer is formed during later calcination, so that the performance of the material is improved. The surface of lithium manganese iron phosphate particles is tightly coated with the composite material, electron transmission can be accelerated, particle pulverization can be reduced, meanwhile, corrosion of corrosive components in electrolyte can be inhibited, interface side reactions such as transition metal ion dissolution can be reduced, and finally the conductivity and cycling stability of the lithium ion battery are remarkably improved.

The invention provides a metal doped silicon carbon negative electrode material and a preparation method thereof, and the preparation method comprises the following steps: a modified amorphous carbon material and a metal silane precursor are respectively prepared, the particle size of the modified amorphous carbon material is 7-8 [mu] m, and the internal pore size of the modified amorphous carbon material is 0.1-10 nm; the modified amorphous carbon material is placed in a chemical vapor deposition reactor, nitrogen is introduced, the temperature is increased to 500-700 DEG C, then composite gas is introduced, the deposition reaction is carried out for 100-800 minutes, a pre-product is obtained, the composite gas comprises a metal silane precursor, doping auxiliary gas and acetylene gas, and the doping auxiliary gas is used for regulating and controlling growth of sediments; and heating the pre-product to 750-850 DEG C for 10-30 minutes, cooling the pre-product to 500-600 DEG C, introducing acetylene gas again, and keeping the temperature for 30-300 minutes to obtain the metal-doped silicon-carbon negative electrode material. Therefore, the electrochemical performance and the cycle life are effectively improved.

Disclosed is a substrate processing method including a gap-fill process capable of preventing pattern damage. The substrate processing method includes a deposition step of depositing an amorphous carbon layer on a substrate having pattern walls formed thereon, wherein a gap is defined between the pattern walls; an etching step of removing an overhang formed at a top of the pattern wall using an etching gas; and a repeating step of repeating the deposition step and the etching step so as to fill the gap with the amorphous carbon layer, wherein the etching gas used in the etching step contains carbon dioxide.

The invention discloses a silicon-tin-carbon composite material as well as a preparation method and application thereof, and the silicon-tin-carbon composite material sequentially comprises a porous silicon core, a first coating layer and a second coating layer from inside to outside, the first coating layer comprises a porous carbon material and tin located in pores of the porous carbon material, and the second coating layer comprises an amorphous carbon coating layer; pores of the porous silicon core contain tin and a porous carbon material. Tin of the silicon-tin-carbon composite material is located in pores of the porous carbon layer, so that the problem of tin expansion and the problem of tin agglomeration in the subsequent high-temperature carbonization process are buffered; meanwhile, a porous composite layer formed by tin and a porous carbon material is compounded to the surface and pores of the porous silicon core, so that the surface defects of porous silicon are repaired, and the expansion of silicon is limited to a certain extent; and on one hand, the outermost coated carbon layer can inhibit the volume expansion of silicon and tin in the charging and discharging process and increase the conductivity of the composite material.

The invention provides a multi-element graded composite hollow microsphere wave-absorbing agent as well as a preparation method and application thereof. The multi-element graded composite hollow microsphere is composed of a hollow core and a composite spherical shell, wherein the hollow inner core is an air cavity, and the composite spherical shell is composed of porous amorphous carbon serving as a continuous phase and carbon nanohorn and magnetic metal composite particles serving as a dispersed phase. According to the scheme, the hollow core of the multi-element graded composite hollow microsphere is the air cavity, the density is low, and electromagnetic waves can be induced to enter the hollow cavity for multi-reflection; the composite spherical shell is composed of porous amorphous carbon serving as a continuous phase and carbon nanohorn-magnetic metal composite particles serving as a dispersed phase, tiny pores in the amorphous carbon can provide more interface polarization, and meanwhile, the amorphous carbon and the carbon nanohorn-magnetic metal composite particles can form a multi-element heterogeneous interface on the surface of the composite spherical shell; through a multi-interface effect and a multi-loss mechanism among the carbon nanohorn, the magnetic metal and the amorphous carbon, the electromagnetic wave loss is effectively enhanced and increased, and the electromagnetic wave absorption capability is enhanced.

The invention discloses a silicon-carbon composite material and a preparation method thereof. The composite material is composed of porous hard carbon, inorganic lithium salt doped with the porous hard carbon and a porous metal frame as a matrix, nano silicon deposited in pores of the matrix, and an amorphous carbon composite material coated on the surface. The preparation method comprises the following steps: uniformly mixing resin, inorganic lithium salt and a porous metal framework, and carrying out hydrothermal reaction, activation and secondary carbonization to obtain a porous carbon complex; and depositing nano silicon and coating the nano silicon with an organic lithium salt through a vapor deposition method to obtain the silicon-carbon composite material. According to the obtained material, expansion is reduced through large-aperture deposited nanometer silicon of the metal frame structure, the defects are reduced through the inorganic lithium salt of the inner core and the organic lithium salt of the outer shell, the ion diffusion rate is increased, and the first efficiency and the rate performance are improved.

The invention provides a graphite composite material, a preparation method thereof and a secondary battery, and relates to the technical field of lithium ion battery negative electrode materials. The graphite composite material comprises an inner core and a shell layer, the inner core comprises metal element doped metal oxide and graphite, the metal element doped metal oxide is embedded between sheet layers of the graphite, the shell layer comprises multi-walled carbon nanotubes and amorphous carbon, and the multi-walled carbon nanotubes are distributed in the amorphous carbon in a 3D net shape. According to the invention, by introducing the doping element, the lithium intercalation active sites of the metal oxide are increased, so that the lithium storage performance of the graphite composite material is improved; through the construction of a core-shell and intercalation structure, the volume expansion of the metal oxide is inhibited, so that the cycling stability of the graphite composite material is improved.

The invention relates to the technical field of powder metallurgy materials, and discloses rare earth microalloyed ultrahigh-strength high-toughness hot work die steel and a preparation method thereof.The die steel is prepared from 4Cr5MoSiV1 pre-alloyed powder, rare earth hydride, boron carbide and porous amorphous carbon powder loaded with a nickel catalyst. The preparation method comprises the steps of material mixing, sheath packaging, graded dynamic reaction thermal devolatilization, hot isostatic pressing densification and heat treatment, in the graded dynamic reaction thermal devolatilization, active hydrogen generated by decomposition of rare earth hydride is used for reducing oxide on the surface of powder, and nickel catalyzed carbon powder is used for capturing water vapor at low temperature to generate CO to be discharged. An oxide film on the surface of the powder is thoroughly removed through in-situ chemical reaction, original particle boundaries are eliminated, meanwhile, a nano strengthening phase with high thermal stability is generated in situ, and the high-temperature strength, impact toughness and tissue compactness of the die steel are remarkably improved.

The invention discloses a preparation method of a phosphorus-doped hard carbon composite material for a sodium battery. The preparation method comprises the following steps: preparing a hard carbon precursor, preparing a phosphorus-doped precursor, preparing a catalyst precursor, preparing a hard carbon composite material, and carrying out pickling purification. Through pre-oxidation treatment on the biomass raw material, oxygen-containing free radicals can be introduced, the structural disorder can be improved, the sodium storage space and the capacity can be improved, phosphorus elements are uniformly distributed into the hard carbon material through a vapor deposition method, meanwhile, graphene and carbon nanotubes are formed in the material, closed pores are increased, the sodium storage space is improved, and the performance of the hard carbon material is improved. According to the present invention, the ion transmission path is shortened, the sodium ion transmission is accelerated, the capacity and the conductivity of the material are enhanced, the material is coated with the amorphous carbon formed by the asphalt, such that the phosphorus expansion can be inhibited, the contact with the electrolyte can be avoided, the capacity and the first effect can be improved, and the phosphorus and the coating layer can be re-distributed while the asphalt coating is performed so as to form the small amount of the phosphorus fiber crystal; and the conductivity and the capacity are improved.

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

The invention provides a silicon-carbon negative electrode material and a preparation method thereof, and particularly relates to the technical field of lithium battery negative electrode materials. The silicon-carbon negative electrode material comprises coating porous carbon, coating silicon deposited in channels of the coating porous carbon and an amorphous carbon layer coating the outer layer of the coating porous carbon, the coating porous carbon comprises porous carbon and a first silicon nitride coating; the first silicon nitride coating coats the interiors of pore channels of the porous carbon and the outer surface of the porous carbon; and the coating silicon comprises silicon and a second silicon nitride coating coated on the surface of the silicon. In the silicon-carbon negative electrode material provided by the invention, the porous carbon is protected through the first silicon nitride coating, side reaction is reduced, charge and discharge stress is buffered, and structural damage is prevented. The second silicon nitride coating relieves the stress of the silicon material and protects the structural integrity. The layered silicon nitride enhances the electrochemical performance, and the amorphous carbon layer reduces the side reaction, thereby improving the efficiency and service life of the battery, and ensuring the double improvement of the battery performance and structural stability.

The invention relates to the technical field of lithium ion battery negative electrode materials, in particular to a preparation process of a silicon-carbon coated negative electrode material which takes bamboo wood as a biomass carbon source and is combined with nano silicon and a dual carbon coating technology, and the preparation process comprises the following steps: step a, sol loading, step b, vacuum impregnation, step c, interface bonding, step d, inner layer coating and step e, outer layer coating. A silicon-carbon interface in-situ bonding technology and a double-layer carbon coating technology are utilized, a sol-gel method is adopted to construct a Si-O-C chemical bond on the surface of bamboo-based carbon, molecular-level anchoring of silicon particles (20-50 nm) on the surface of a carbon skeleton is achieved, the interface separation problem of traditional mechanical mixing is solved, meanwhile, inner-layer amorphous carbon (2-3 nm) is generated in cooperation with bamboo wood pyrolysis gas, and the surface of the bamboo-based carbon is separated. Then bamboo vinegar is carbonized to form an outer graphitized carbon shell (5-8nm), and the double carbon layers cooperate to inhibit volume expansion of silicon, so that the problem of volume expansion of silicon is solved, and the first charge-discharge efficiency of the battery and the capacity retention rate after circulation are effectively improved.

The invention belongs to the technical field of coating material preparation, and particularly relates to a copper-titanium co-doped amorphous carbon coating and a high-throughput preparation method. The invention firstly provides a high-throughput preparation method, the method does not need to prepare a plurality of target materials with different metal contents, a plurality of deposition samples can be obtained only by preparing a plurality of matrixes once through ingenious arrangement of matrix sample positions and specific quality control index requirements, and then test screening is carried out in combination with the quality control index requirements. And the bimetallic-doped amorphous carbon coating with the optimal performance can be rapidly screened out with relatively low process cost for practical application.

The present invention provides a method for preparing a composite coating of a carbon fiber thermal insulation material, the method comprising: purifying the carbon fiber, then doping the surface with a composite metal element, placing the doped carbon fiber in a high-temperature furnace for surface carbon coating, cracking the organic carbon source on the surface of the carbon fiber under the catalytic action of the composite metal element to form amorphous carbon, then performing surface modification to obtain surface-modified carbon fiber, and then stirring and mixing with the components in the coating, applying, and obtaining a composite coating of a thermal insulation material containing carbon fiber. The carbon fiber of the present invention has good performance, and through the catalysis of the composite metal during the pyrolysis process, amorphous carbon with a porous structure is formed on the surface, which has good thermal insulation ability. The coating of the present invention has extremely high thermal insulation ability, corrosion resistance, wear resistance and adhesion ability, and can be used for thermal insulation coatings in various thermal protection systems.

The present invention belongs to the field of liquid flow energy storage battery materials, and particularly relates to a multi-dimensional conductive material, a preparation method thereof, and an application thereof in a vanadium redox flow battery. The present invention uses a biomass precursor to bond graphite and multi-walled carbon nanotubes, and through stepwise pyrolysis, converts the carbon-based biomass into graphitized carbon nanotubes. The amorphous carbon in the graphite and the original carbon nanotubes is also further graphitized, and finally a multi-dimensional conductive material with carbon nanotubes inserted into a graphite matrix is formed. The multi-dimensional characteristics on the surface of the multi-dimensional conductive material are beneficial to forming a longitudinal conductive path on the bipolar plate, reducing the vertical bulk resistance of the bipolar plate, and also facilitating the wetting of epoxy resin between conductive particles and the mechanical interlocking of its molecular chains, improving the mechanical strength of the bipolar plate, effectively enhancing the service performance of the bipolar plate, meeting the requirements of long-term operation of the flow battery, relatively reducing the material cost of the flow battery, strongly promoting the industrialization of the bipolar plate, and having good application value.

Disclosed in the present application are a negative electrode material and a preparation method therefor, a negative electrode plate and a battery. The negative electrode material has a core-shell structure, wherein the inner core is boron-doped graphite, and the shell comprises porous titanium oxide, amorphous carbon and a conductive agent. By coating the boron-doped graphite with the shell comprising the porous titanium oxide, the amorphous carbon and the conductive agent, all the components cooperate with each other, such that not only is the ion / electron transport rate of the negative electrode material significantly improved, and the conductivity improved, but intercalation of lithium ions of a lithium battery, which is formed by the negative electrode material, can also be improved, the loss of irreversible capacity of the battery is reduced, and the first efficiency and rate capability of the battery are improved. Especially, due to the use of the porous titanium oxide, the structure of the negative electrode material is also more stable, thereby significantly improving the cycle performance of the battery.

The invention provides a silicon-carbon negative electrode material, a preparation method thereof and a secondary battery. The silicon-carbon negative electrode material comprises a carbon skeleton, nano silicon particles and a carbon coating layer, wherein the carbon skeleton is a complex of carbon nanotubes and amorphous carbon. The amorphous carbon has a hierarchical pore structure, and the hierarchical pore structure comprises 65-85% of micropores and 15-35% of mesopores. At least part of the nanometer silicon particles are contained in the grading hole structure, and the carbon framework is coated with the carbon coating layer. The silicon-carbon negative electrode material has a carbon skeleton with a hierarchical pore structure, volume expansion of nano silicon can be effectively relieved, the cycle performance of the material is improved, and a three-dimensional conductive network constructed by the carbon nanotubes is also beneficial to improvement of the rate capability of the material.