470 results about "Carbon matrix" patented technology

An integrated carbon honeycomb structure material and its preparation method are disclosed, belonging to the field of carbon materials technology. Based on a co-sacrificial template low-temperature pyrolysis strategy, the target material can be obtained through three main steps: preparation of a metal salt-colloidal microsphere template precursor, precursor pressing and molding, and subsequent calcination and carbonization. This technology has the characteristics and advantages of simple preparation process, regular and controllable macroscopic structure of the sample (such as shape, area, and thickness), rich and tunable chemical composition, and three-dimensional interconnection of graphene carbon matrix. It has great application potential in many fields such as electrochemical energy storage, catalysis, gas separation, adsorption, and electromagnetic shielding.

The invention relates to a silicon-carbon composite material and a preparation method thereof, a negative pole piece, a secondary battery and a device, the silicon-carbon composite material comprises a carbon matrix with a pore structure and a silicon-based material distributed in the pore structure of the carbon matrix, and the silicon-carbon composite material contains phosphorus element. The silicon-based material in the silicon-carbon composite material improves the capacity of the carbon matrix, and the carbon matrix with the pore structure can be used as a buffer medium for volume expansion of the silicon-based material in the charging and discharging process while improving the conductivity of the silicon-based material, so that the problem that the volume of the secondary battery is increased due to silicon expansion is effectively relieved; and the phosphorus element doped in the skeleton of the carbon matrix is beneficial to improving the electronic conductivity of the material, so that the cycle performance of the battery is improved.

A method of fabricating a biochar composite product comprises thermally treating a precursor composition by heating the precursor composition according to a heating profile to provide a biochar composite product, the precursor composition comprising biochar and a natural binder other than lignin, wherein the natural binder forms a solid, porous, covalently bound carbon matrix at or above a threshold temperature, wherein the biochar composite product comprises a plurality of porous, carbonaceous particles and the solid, porous, covalently bound carbon matrix on surfaces of particles in the plurality such that neighboring particles are adhered together. The biochar composite products and methods of using the products are also provided.

The invention relates to the technical field of batteries, in particular to a porous carbon material, a silicon-carbon composite material and application of the porous carbon material and the silicon-carbon composite material. According to the porous carbon material, the micropore rate phi, the pore volume Pv and the compressive strength Cs meet the relational expression that (Cs * phi) / Pv is larger than or equal to 550 and smaller than or equal to 1050, and the micropore rate phi gt; and the compressive strength Cs is 600 to 850 MPa. The porous carbon material provided by the invention has high microporosity, and the microporosity phi, the pore volume Pv and the compressive strength Cs of the porous carbon material meet the relation that (Cs.phi) / Pv is more than or equal to 550 and less than or equal to 1050, so that the particle size of silicon particles can be effectively reduced, the absolute expansion of silicon in a carbon matrix is reduced, and the first effect and the cycling stability of the silicon-carbon composite material are improved.

The invention provides an electric energy storage system, a graphene / carbon nanotube composite material, a capacitor, a secondary battery, a preparation method and an application. The electric energy storage system comprises a capacitor, the capacitor comprises a positive plate, the positive plate comprises a graphene / carbon nanotube composite material, the graphene / carbon nanotube composite material comprises a three-dimensional network skeleton, the three-dimensional network skeleton comprises a carbon matrix and doping elements, the carbon matrix is formed by compounding graphene and a carbon nanotube, and the doping elements are doped with the carbon matrix. The doping elements comprise a nitrogen element and a sulfur element, and holes are formed in the surface of the three-dimensional network framework. The electric energy storage system has excellent electrochemical performance, can release high energy density under high power density, and is long in cycle life.

A silicon-carbon composite material and a preparation method therefor, a negative electrode sheet, a secondary battery, and a device. The silicon-carbon composite material comprises a carbon matrix having a pore structure and a silicon-based material distributed in the pore structure of the carbon matrix, and the silicon-carbon composite material contains the element phosphorus. The silicon-based material in the silicon-carbon composite material increases the capacity of the carbon matrix, and the carbon matrix having the pore structure improves the conductivity of the silicon-based material, and can also be used as a buffer medium for volume expansion of the silicon-based material during charging and discharging, so that the problem of increase of the volume of a secondary battery due to silicon expansion is effectively relieved; in addition, the element phosphorus doped in the framework of the carbon matrix is beneficial to improving the electronic conductivity of the material, thus improving the cycle performance of the battery.

The invention discloses a molybdenum carbide / nitrogen-doped carbon composite material and a preparation method and application thereof, and belongs to the technical field of new energy materials and devices. The preparation method comprises the following steps: uniformly mixing ammonium molybdate, glucose and g-C3N4, and carrying out hydrothermal and high-temperature calcination treatment to obtain a composite material (Mo2C / NC) in which a nano Mo2C electrocatalyst is dispersed and distributed on a nitrogen-doped carbon matrix. The nitrogen-doped carbon in the composite material has a hierarchical porous structure, so that the electrolyte permeation and ion transmission capabilities are enhanced; the nitrogen-doped active sites not only enhance the adsorption performance of the porous carbon on polysulfide, but also improve the catalytic activity by optimizing the coordination structure of Mo2C; mo2C can chemically adsorb and efficiently catalyze reversible conversion of polysulfide, and the utilization rate of active substances is increased. When the composite material is used as a positive electrode additive of a lithium-sulfur battery, dissolution and shuttling of polysulfide can be effectively inhibited, so that the battery has high specific capacity, rate capability and excellent cycle reversibility.

A negative electrode material, a negative electrode sheet and a battery. The negative electrode material comprises a carbon matrix and an active substance, wherein the carbon matrix is provided with pores, and the active substance is at least partially distributed in the pores. The area proportion of the pores having a pore diameter larger than 50 nm in any section of the negative electrode material is α, which satisfies: α≤10%, wherein α is obtained by means of the following test method: in an image as shown by the SEM section treatment of a single negative electrode material particle, any a×b region is selected, where a=1-10 μm and b=1-10 μm, the sum of the sectional areas of pores having a pore diameter larger than 50 nm in the region of the section of the single negative electrode material particle is denoted as S0, the sectional area of the single negative electrode material particle in the region is denoted as S, the area proportion of the pores having a pore diameter larger than 50 nm in the section of the single negative electrode material particle is defined as α', where α'=S0 / S, and α is the arithmetic mean value of α' values of at least 10 negative electrode material particles.

A gas turbine engine includes a rotor that that has a seal surface, a shaft that has an annular seal channel that opens to the seal surface, and a seal disposed in the annular seal channel for sealing against the seal surface. The seal is made of a composite having carbon fibers disposed in a carbon matrix.

The invention provides an electrode material, a preparation method thereof and a sodium ion battery. The electrode material comprises a carbon substrate and metal nitride doped in the carbon substrate, the carbon matrix has a closed hole in which at least a portion of the metal nitride is located. The carbon substrate is provided with the closed hole, at least part of the metal nitride is filled in the closed hole, the closed hole can prevent the metal nitride from escaping from the hole, the metal nitride in the closed hole can improve the electric field and the sodium storage activity of the central area of the closed hole, the internal resistance of sodium filled in the closed hole is reduced, polarization is inhibited, and sodium precipitation is reduced; the sodium storage utilization rate of the central area of the closed hole is improved, and the sodium storage capacity performance of the electrode material is further improved.

The invention discloses a mesophase pitch carbon matrix modified high-thermal-conductivity C / SiC composite material and a preparation method thereof, the material is subjected to high-thermal-conductivity matrix modification through mesophase pitch melt impregnation, in-situ mesophase inversion and in-situ carbonization, and mesophase pitch carbon fibers are combined as a reinforcement, so that the high-thermal-conductivity C / SiC composite material is obtained. The mesophase pitch carbon matrix modified high-thermal-conductivity C / SiC composite material is obtained by densifying a silicon carbide matrix by adopting a polycarbosilane melt impregnation and in-situ cracking process, has excellent mechanical and high-thermal-conductivity properties, can be widely applied to the front edge, the end head and other parts of a hypersonic aircraft, and can effectively improve the use temperature and the service environment of the material. Meanwhile, the preparation process is simple, the equipment use requirement is low, and the material preparation process period and cost can be correspondingly reduced.

The invention provides a negative electrode material and a preparation method thereof, and a battery, the negative electrode material comprises an active substance, the active substance comprises a carbon matrix and silicon particles, the carbon matrix has holes, and at least part of the silicon particles are distributed in the holes of the carbon matrix; the negative electrode material contains an oxygen element and a nitrogen element, the mass content of the oxygen element is A%, and the mass content of the nitrogen element is B%; the powder conductivity of the negative electrode material is PS / m and meets the following relation: (A + B) / P is less than or equal to 3. According to the negative electrode material provided by the invention, the gas production phenomenon of the negative electrode material can be reduced on the premise of keeping relatively high electronic conductivity.

The negative electrode material contains a nitrogen element and comprises a carbon substrate and an active substance, the carbon substrate is provided with holes, at least part of the active substance is arranged in the holes of the carbon substrate, a region which is 200 nm deep from the outer surface of the negative electrode material is defined as a first region, and the first region is defined as a second region. An area which is 1000 nm deep from the outer surface of the negative electrode material is a second area, the atomic percentage content of the nitrogen element in the first area is alpha, and the atomic percentage content of the nitrogen element in the second area is beta, alphalt; beta; the deposition parameter of the active substance is defined as gamma, and gamma is greater than or equal to 0.86. In the negative electrode material, relatively most of the active substances are distributed in the pores of the carbon matrix, so that the gas production behavior of the negative electrode material is reduced, and the conductive performance of the carbon matrix is favorably exerted, so that the secondary battery applying the negative electrode material has relatively high specific discharge capacity, initial coulombic efficiency and relatively good cycle stability.

A self-supporting cotton biomass carbon loaded red-phosphorus sodium ion battery negative electrode material and a preparation method therefor. The self-supporting cotton biomass carbon loaded red-phosphorus sodium ion battery negative electrode material comprises a carbon matrix and nanoscale red phosphorus loaded in pores of the carbon matrix; the carbon matrix is obtained by taking cotton as a biomass carbon precursor and carrying out high-temperature carbonization and etching treatment in argon / ammonia mixed gas. The preparation method comprises: placing cotton in an argon / ammonia mixed gas atmosphere for high-temperature treatment; cooling in an inert gas atmosphere to obtain a carbon matrix; and mixing the carbon matrix with red phosphorus, and carrying out packaging, calcining, cooling, washing and drying to obtain the self-supporting cotton biomass carbon loaded red-phosphorus sodium ion battery negative electrode material. The self-supporting cotton biomass carbon loaded red-phosphorus sodium ion battery negative electrode material has the advantages of high reversible specific capacity and excellent cycling stability.

The invention relates to the technical field of soil remediation and saline-alkali soil treatment, and discloses a nano-carbon-based slow-release saline-alkali soil conditioner and a gradient controlled release method thereof.The formula comprises a layered nano-carbon matrix, a humic acid intercalation compound, a pH response type cross-linking agent, a calcium ion modifier and a phosphate radical modifier; the method comprises the following steps: constructing a self-regulation repair system for synchronously optimizing salt reduction, nutrient supply and ion balance through a three-dimensional synergistic mechanism of pH response type sodium ion targeted adsorption, microbial activity driven nutrient controlled release and calcium-sodium dynamic replacement. A nano carbon-humic acid layered composite structure is used for synergic desalination and slow-release fertilizer supply, a Ca < 2 + >-PO4 < 3-> gradient ion replacement system is combined for synchronous salt reduction and structure fixation, a pH response coating technology is used for realizing accurate release of nutrients triggered by microbial activity, and a three-dimensional interpenetrating network and graded pores are used for guaranteeing the long-acting stability of the material. And finally, multiple repairing functions are integrated into a single material.

The invention relates to the technical field of lithium ion batteries, and particularly discloses a silicon-carbon-based composite material, a preparation method thereof and application of the silicon-carbon-based composite material in a lithium ion battery. The silicon-carbon-based composite material is prepared by taking a carbon nanotube as a seed crystal through a silicon-carbon co-deposition reaction, and no nanoscale pores exist between a disordered carbon matrix and silicon particles of the silicon-carbon-based composite material. According to the structural characteristics, the transmission bottleneck problem of a traditional CVD silicon carbon material is fundamentally solved, the dynamic performance of the material is remarkably improved, and the situation of voltage and capacity diving at the discharge tail end is thoroughly avoided. The continuous production of the silicon-carbon-based composite material is realized, the production efficiency of the lithium ion battery is remarkably improved, the production cost of the lithium ion battery is reduced, the dependence on special raw materials is reduced, the limitation of customized porous carbon production is avoided, and the method has obvious economic and market advantages and is worthy of popularization and application. The invention provides a negative electrode material with excellent comprehensive performance for the lithium ion battery, and has great significance for promoting the technical development of the lithium ion battery.

The invention discloses a preparation method of an electrode composite material, the electrode composite material and application of the electrode composite material, and the preparation method comprises the following steps: sequentially crushing and pickling a soft carbon raw material to obtain a soft carbon precursor; placing the soft carbon precursor, a hard carbon material and absolute ethyl alcohol in a sand mill for sanding treatment, and uniformly mixing to obtain a mixed dispersion liquid; carrying out drying treatment on the mixed dispersion liquid to obtain a composite carbon matrix precursor; placing the composite carbon matrix precursor in a rotary furnace, performing carbonization treatment in an inert gas environment, and performing grinding, crushing and sieving to obtain a carbonized compound; placing the carbonized compound in a rotary furnace, and activating under the condition of carbon dioxide gas and / or water vapor to obtain a composite carbon matrix containing a pore structure; and introducing gas containing a silicon source into the rotary furnace, depositing nano silicon in pores of the composite carbon matrix through chemical vapor deposition, and crushing to obtain the electrode composite material.

The invention provides a mesoporous silicon carbon negative electrode material and a preparation method and application thereof, and relates to the technical field of battery negative electrode materials, the mesoporous silicon carbon negative electrode material comprises a mesoporous carbon matrix and silicon; the mesoporous carbon matrix can be a spherical, spheroidic or irregular block, the mesoporous carbon matrix has mesoporous structures, and preferably, the mesoporous structures are in ordered distribution; according to the invention, the preparation of the uniform mesoporous structure is realized, the volume expansion of the silicon is effectively relieved, the close combination of the silicon and the carbon is realized by vapor deposition of the silicon on the mesoporous sphere carbon matrix material, and the cycling stability of the material is improved. According to the meso-porous silicon carbon negative electrode material provided by the invention, by optimizing the structural design of the material, the problems of silicon volume expansion, infirm interface bonding, complex preparation process and the like in the prior art are solved.

The present application relates to the technical field of negative electrode materials. Provided are a negative electrode material and a battery. The negative electrode material comprises an inner core and a coating layer located on at least part of the surface of the inner core. The inner core comprises a carbon matrix, and an active substance and boron element distributed in the carbon matrix. The active substance comprises a silicon material and a metal material, and at least part of the silicon material being connected to the metal material. The negative electrode material of the present application has low expansion, ultra-high conductivity, and high initial coulombic efficiency.

The invention relates to an asphalt-based porous hard carbon material prepared under assistance of chloride addition and a preparation method of the asphalt-based porous hard carbon material, and belongs to the field of alkali metal ion battery negative electrode materials. The method aims at solving the problems that an existing treatment method for preparing a hard carbon material by taking asphalt as a raw material is tedious and high in cost. The preparation method of the asphalt porous hard carbon material comprises the following steps: mixing hard carbon precursors (pure asphalt, pre-oxidized asphalt, pre-carbonized asphalt and the like) and chloride according to a ratio, and synthesizing a sample through a solid sintering method. According to the hard carbon material, a large number of micropores and mesopores of 2 nm and below are introduced into a carbon matrix of the hard carbon material to serve as storage point locations of sodium ions, so that the hard carbon negative electrode material with a highly disordered structure is obtained, higher capacity and rate capability (219-350 mAh g <-1 >) are obtained, the first-circle coulombic efficiency is 70-80% under the current density of 2Ag <-1 >, and the capacity retention rate is 70-78% after 400 cycles. According to the preparation method, the charge-discharge capacity and the cycling stability of the hard carbon material can be improved, and asphalt is adopted as a hard carbon precursor and is rich in source and low in cost.

The invention provides a preparation method of a long-life multi-disc type carbon ceramic brake disc, which comprises the following steps: preparing a three-dimensional needling movable disc and static disc prefabricated body, performing chemical vapor deposition treatment on the prepared prefabricated body, machining the treated prefabricated body into a base body according to the size requirement of a finished product by adopting a machining method, and performing vacuum drying on the base body to obtain the long-life multi-disc type carbon ceramic brake disc. And respectively carrying out in-situ reaction densification on the carbon-carbon substrates of the movable disc and the static disc and the ceramic particles to obtain a high-density movable disc and a low-density static disc. The dynamic disc and the static disc are paired and subjected to differential matching, density regulation and control are strict, the density of the dynamic disc is high (2.2-2.35 g / cm < 3 >), the density of the static disc is low (1.8-1.9 g / cm < 3 >), dynamic and static cooperation and synergistic effect are achieved, the friction coefficient is maximized, abrasion is minimized, and the service life of a product is prolonged.

The invention relates to the field of batteries, in particular to a preparation method and application of an iron-cobalt sulfide / nitrogen-doped carbon composite material based on a spray drying method. The method comprises the following steps: mixing a 2-methylimidazole solution and a cobalt salt solution, performing spray drying to obtain purple precursor powder, performing recrystallization and iron ion exchange to obtain Fe / ZIF-67, and finally forming the ZIF-67 skeleton derived iron-cobalt sulfide / nitrogen-doped carbon composite material by a gas-phase vulcanization method. The Fe / ZIF-67 provided by the invention has a nanoscale size and high structural stability. When the iron-cobalt sulfide / nitrogen-doped carbon composite material is used as a sodium-ion battery negative electrode material, a built-in electric field constructed by an iron-cobalt sulfide heterostructure can remarkably improve ion diffusion kinetics; meanwhile, the nitrogen-doped carbon matrix can effectively relieve the volume change of the iron-cobalt sulfide heterojunction in the electrochemical reaction process while improving the conductivity of the composite material, so that the nitrogen-doped carbon matrix shows excellent and stable sodium storage performance.

The invention relates to a negative electrode material and a preparation method thereof, and a lithium ion battery, the negative electrode material comprises a carbon matrix and an active substance, the carbon matrix has pores, and at least part of the active substance is distributed in the pores of the carbon matrix. The carbon dioxide in the pores of the carbon matrix in the negative electrode material can be quickly dissolved in the electrolyte and promote the electrolyte to enter the pores of the negative electrode material, and meanwhile, in the lithium intercalation process, the dissolved carbon dioxide can reduce the decomposition rate of FEC and reduce the formation of a loose and irregular SEI film, so that the lithium intercalation efficiency is improved. And the binding effect of fluorine in the lithium fluoride SEI film and lithium in the lithium silicon alloy is improved, so that the capacity and the first effect of the negative electrode material are improved.

A silicon-carbon composite material and a preparation method therefor, a negative electrode and a battery specifically relate to the field of battery technologies. The silicon-carbon composite material is composed of silicon-carbon composite material particles, wherein the silicon-carbon composite material particles include a C / C composite porous material and silicon nanoparticles located in pore channels and on a surface of the C / C composite porous material; the C / C composite porous material includes a first carbon material and a second carbon material; the first carbon material is a porous carbon matrix, and the second carbon material is distributed throughout an interior of the C / C composite porous material and further throughout the silicon-carbon composite material. For the silicon-carbon composite material provided, by introducing the second carbon material to prepare the C / C composite porous material, a strong and tough electroconductive network is formed between the C / C composite porous material and the silicon nanoparticles, thereby avoiding silicon from losing contact with the carbon matrix material when changing in volume, and further improving electronic and ionic conductivities of the silicon-carbon composite material, and prolonging service lifetime of the material.

The invention belongs to the technical field of preparation of wave-absorbing materials, and particularly relates to a cobalt-based nitrogen-doped carbon nano composite material with a hollow cubic structure as well as a preparation method and application thereof. Comprising the following steps: taking ZnCo-ZIF with a nano cubic structure as a core, coating ZnCo-ZIF with polydopamine by adopting a precipitation method to form a precursor with a core-shell structure, and carbonizing the precursor at 800-900 DEG C to obtain the cobalt-based nitrogen-doped carbon nano composite material with the hollow cubic structure. According to the invention, the dielectric loss capability can be enhanced by using the conductivity and interface polarization effect of the coated carbon layer, and the Co particles introduce strong magnetic loss; meanwhile, due to interface polarization caused by abundant heterogeneous interfaces existing between the Co particles and the coating carbon layer, between the magnetic particles and the carbon nanotubes and between the carbon matrix and the carbon nanotubes in the composite material, the impedance matching characteristic can be improved, and high reflection loss and wide effective absorption bandwidth can be achieved under the low matching thickness.

A silicon-carbon composite material and a preparation method thereof, a negative electrode plate, and a secondary battery are disclosed. The silicon-carbon composite material includes a porous carbon matrix and silicon-based particles. The porous carbon matrix internally includes a plurality of pore channels with a width of 5 nm-50 nm. The silicon-based particles are distributed in the pore channels, and the porous carbon matrix meets: 1.0×10−7≤Vtotal / Stotal≤10.0×10−7, where Stotal is the total surface area occupied by the pore channels with the width of 5 nm-50 nm, and the measurement unit is: ×104 cm2 / g; and Vtotal is the total pore volume occupied by the pore channels with the width of 5 nm-50 nm. The silicon-carbon composite material has high electrical conductivity. When being applied to a negative electrode of the secondary battery, the silicon-carbon composite material can effectively increase the volume capacity and energy density of the secondary battery.

The invention relates to the technical field of aerogel wave-absorbing materials, in particular to a multi-scale structure composite carbon aerogel wave-absorbing material and a preparation method thereof. The aerogel wave-absorbing material comprises a three-dimensional skeleton, a functional component and a conductive network. The three-dimensional skeleton is of a hierarchical porous structure formed by crosslinking two-dimensional graphene oxide and one-dimensional aramid nanofibers through hydrogen bonds, the functional component is zero-dimensional CoFe2O4 nanoparticles which are uniformly dispersed on the three-dimensional skeleton through in-situ growth, and the conductive network is an sp / sphybrid carbon matrix formed by carbonizing the three-dimensional skeleton and the functional component at high temperature. Through multi-dimensional cooperative construction of the zero-dimensional CoFe2O4 nanoparticles, the one-dimensional aramid nanofibers and the two-dimensional graphene, a rich heterogeneous interface and a polarization center are formed in the material, the electromagnetic wave loss capacity is remarkably enhanced, the broadband efficient wave absorbing requirement can be met, and the electromagnetic compatibility of aerospace electronic equipment is remarkably optimized.

The embodiment of the invention relates to a scandium-based negative electrode material and a preparation method and application thereof. The preparation method comprises the following steps: dissolving a scandium-containing compound in deionized water to prepare a homogeneous solution, adding a coagulator, and stirring and mixing to obtain a first solution; placing the first solution in a heating device, and enabling a molecular chain of the coagulator to be broken and dissolved to form a cross-linked sol containing a scandium ion solution; standing the sol at room temperature to obtain solid gel; carrying out hot-pressing curing on the solid gel to obtain a cured sample with uniformly dispersed scandium ions; placing the cured sample in a tubular furnace for heat treatment to obtain a scandium nitride-containing carbon matrix, then placing the scandium nitride-containing carbon matrix in a surface oxidant solution for soaking to modify the scandium nitride-containing carbon matrix, washing the modified sample with water, performing suction filtration, and drying to obtain a modified scandium-based carbon matrix; or directly washing and filtering the scandium nitride-containing carbon matrix, and drying to obtain an unmodified scandium-based carbon matrix; and finally, calcining in an oxidizing atmosphere to remove residual carbon so as to obtain the scandium oxide nanoparticles.

This application provides a negative electrode active material, a secondary battery, and an electrical device. The silicon-carbon negative electrode material includes a silicon-carbon composite material, which comprises a first silicon-carbon composite particle and a second silicon-carbon composite particle. The first silicon-carbon composite particle comprises a first carbon matrix with a porous structure and a first silicon-based material disposed within the porous structure of the first carbon matrix. The second silicon-carbon composite particle comprises a second carbon matrix with a porous structure and a second silicon-based material disposed within the porous structure of the second carbon matrix. Furthermore, the mass percentage of silicon in the first silicon-carbon composite particle is greater than the mass percentage of silicon in the second silicon-carbon composite particle. This silicon-carbon negative electrode material exhibits both high specific capacity and good cycle stability, thereby improving the energy density and cycle performance of the battery.

The invention relates to the technical field of sodium ion batteries, in particular to a coated modified high-entropy sodium vanadium phosphate positive electrode material as well as a preparation method and application thereof. The coated modified high-entropy sodium vanadium phosphate positive electrode material comprises a core material and a poly (3, 4-ethylenedioxythiophene): poly (styrene sulfonate) coating layer coated on the surface of the core material, the core material comprises a sodium vanadium phosphate / carbon matrix material and metal elements doped in the sodium vanadium phosphate / carbon matrix material, and the metal elements comprise at least five of Al, Cu, Ru, Ag, Ni, Co, Zn, Ti, Zr, Mg, Mn and Mo elements. The coated modified high-entropy sodium vanadium phosphate positive electrode material provided by the invention can effectively enhance ionic conductivity, electronic conductivity and interface stability of the positive electrode material, can inhibit side reaction between a sodium vanadium phosphate positive electrode and an electrolyte and dissolution of vanadium metal in a circulation process, and has excellent cycle performance and rate capability.