35results about How to "Facilitate de-intercalation" patented technology

The invention belongs to the technical field of lithium batteries, and discloses a lithium nickel manganese oxide positive electrode material, a preparation method thereof and a lithium ion battery. Wherein the lithium nickel manganese oxide positive electrode material has a regular truncated octahedron single crystal structure, and the ratio K of a (111) crystal face orientation parameter to a (100) crystal face orientation parameter in an XRD (X-Ray Diffraction) spectrogram of the lithium nickel manganese oxide positive electrode material is 1-1.6. The lithium nickel manganese oxide positive electrode material provided by the invention has excellent rate capability and cycling stability, and can be well applied to production and manufacturing of lithium ion batteries.

The invention belongs to the technical field of lithium ion batteries, and particularly discloses a lithium ion battery positive electrode material, a preparation method thereof and a lithium ion battery. The lithium ion battery positive electrode material comprises a lithium-rich manganese-based positive electrode material and F-doped ferric cobaltate coating at least part of the surface of the lithium-rich manganese-based positive electrode material, the chemical formula of the F-doped ferric cobaltate is FeCo2O4-0. 5xFx, and x is larger than or equal to 0.01 and smaller than or equal to 0.06. According to the lithium ion battery positive electrode material, the lithium-rich manganese-based positive electrode material is coated with FeCo2O4-0. 5xFx, the structural stability of the lithium-rich manganese-based positive electrode material can be effectively improved, the FeCo2O4-0. 5xFx coating layer has a high Fermi level and excellent conductivity, and the ionic conductivity of the lithium-rich manganese-based material can be effectively improved.

The invention provides a preparation method of a high-rate and high-sphericity lithium iron phosphate positive electrode material, which comprises the following steps: weighing iron phosphate and a lithium source according to a certain proportion, dispersing in pure water, and mixing and sanding to obtain slurry A; under a stirring condition, adding a small amount of fluorine source into the slurry A to obtain lithium fluoride doped slurry B; and under the stirring condition, adding an organic carbon source into the slurry B to prepare an electrostatic spinning solution C, and drying and calcining at high temperature to obtain the high-rate and high-sphericity lithium iron phosphate composite positive electrode material. The preparation method comprises the following steps: synthesizing a lithium fluoride doped stock solution through an in-situ reaction of a fluorine source and a lithium source, and preparing a uniformly doped precursor through electrostatic spinning; the generated lithium fluoride is used as a fluxing agent to promote the formation of high-sphericity lithium iron phosphate in the sintering process; and meanwhile, the doping of fluorine ions weakens the interaction between Li and O, so that the lithium ions can be separated / embedded in a bulk phase during charging and discharging, and the conductive carbon layer is rich in lithium fluoride, so that the migration efficiency of the lithium ions at a positive electrode / electrolyte interface is improved.

The invention discloses a negative plate, a lithium ion battery and electric equipment. The negative plate comprises the negative plate, the lithium ion battery and the electric equipment. The negative plate comprises a negative current collector and a negative active material layer located on at least one side of the negative current collector, the negative active material layer comprises a negative active material, and the negative active material comprises a graphite material, a hard carbon material and a silicon-based material; the particle size D50 of the graphite material, the particle size D '50 of the hard carbon material and the particle size D' '50 of the silicon-based material meet the conditions that 1.5 < = D50 / D' 50 < = 2.5 and 1.1 < = D '50 / D' '50 < = 3. According to the scheme, through the matching of the sizes and the particle sizes of the graphite, the hard carbon and the silicon-based material, the short plate of low compaction density of the hard carbon is effectively improved, the overall compaction density of the negative pole piece is improved, the energy density of the battery is favorably improved, the infiltration of electrolyte is facilitated, the liquid retention of the pole piece is improved, the rapid embedding of lithium ions is also facilitated, and the rate capability is improved.

The invention provides a metal organic framework sodium ion battery positive electrode material Mn-PTO, a preparation method and application, and belongs to the technical field of battery development. According to the material, an organic ligand pyrene tetraketone with conjugate extension is selected, 2, 7-dicarboxyl-4, 5, 9, 10-pyrene tetraketone PTO-(COOH) 2 is synthesized through a series of reactions, and the material has four energy storage sites and can provide high specific capacity. The high reversible specific capacity of 160.1 mAh g < 1 > can be achieved under the current condition of 0.1 A g < 1 >; even under the current condition of 5A g < 1 >, the reversible specific capacity of 118.1 mAh g < 1 > can be realized after 7000 cycles. And stable circulation can be carried out for 10000 times under the high current of 10A g < 1 >. Therefore, the material has huge potential in the aspect of being used as a sodium-ion battery positive electrode.

The invention discloses a battery negative electrode material and a preparation method thereof, and relates to the technical field of batteries. The battery negative electrode material comprises an inner core, a titanium dioxide coating layer coated on the surface of the inner core, a lithium titanate coating layer coated on the surface of the titanium dioxide coating layer, a carbon coating layer coated on the surface of the lithium titanate coating layer and a polymer coating layer coated on the surface of the carbon coating layer, the inner core comprises a silicon-based negative electrode material; the polymer coating layer comprises at least one of polyaniline, polythiophene and polypyrrole. Under the action of the four coating layers, the integrity of the silicon-based negative electrode material can be kept, direct contact between the silicon-based negative electrode material and an electrolyte is avoided, side reactions are reduced, the capacity fading of the battery in the charge-discharge cycle process is reduced, and the rate capability and the cycle stability of the battery are improved.

The invention discloses a sulfur-doped starch-based porous hard carbon material, a preparation method thereof and application of the sulfur-doped starch-based porous hard carbon material in a sodium-ion battery. The particle size D50 of the material is 2-15 [mu] m, the mesoporous volume is 0.10-0.40 cm < 3 > / g, the average pore size is 5-35 nm, the pore size range is 0.5-100 nm, and the sulfur element accounts for 0.5-5 wt% of the sulfur-doped hard carbon material. By reasonably controlling the pore size in the precursor, the generation of a macroporous structure which is not beneficial to sodium ion storage in the subsequent carbonization process is avoided, so that the optimization of the contrast surface area, the defect site and the closed pore structure is realized, and the sulfur-doped porous hard carbon material with good electrochemical performance is designed. The hard carbon material used as the negative electrode material of the sodium ion battery has the advantages of high reversible specific capacity and high first coulombic efficiency, keeps relatively high rate capability of a porous structure, and has a good application prospect in the application of the sodium ion battery.

The invention discloses a lithium manganese iron phosphate positive electrode material and a preparation method thereof, and belongs to the technical field of lithium batteries, the preparation method of the lithium manganese iron phosphate positive electrode material comprises the following steps: dissolving a soluble iron source, a soluble manganese source and a complexing agent in 100 mL of deionized water, adjusting the pH value of the mixed solution to 2-4, and heating and stirring for 2-6 h to obtain xerogel; calcining the dry gel, taking out, cooling and grinding to obtain powder A; calcining the powder A in a nitrogen atmosphere, and grinding to obtain powder B; uniformly mixing the powder B, a lithium source, a phosphorus source, a carbon source and 70mL of deionized water, sanding, and spray-drying slurry after sanding to obtain powder C; and calcining the powder C in a nitrogen atmosphere, crushing, and sieving to obtain the lithium iron manganese phosphate positive electrode material. The lithium manganese iron phosphate positive electrode material prepared by the method has excellent conductivity and cycle performance.

The invention provides a ternary positive electrode material and a preparation method thereof, a positive electrode and a lithium ion battery, belongs to the technical field of lithium ion batteries, and can at least partially solve the problem that the capacity exertion of the existing ternary positive electrode material is limited. The preparation method of the ternary positive electrode material comprises the following steps: performing first sintering on a first sintering raw material to obtain a first sintering product; the first sintering raw material comprises a ternary precursor, a main lithium source and lithium sulfate, and the ternary precursor comprises a nickel element, a cobalt element and a manganese element; carrying out second sintering on the second sintering raw material to obtain a second sintering product, and preparing the ternary positive electrode material by using the second sintering product, the second sintering raw material comprises the first sintering product.

The present invention relates to a high-capacity EFB start-stop battery positive lead paste and a preparation method thereof, belonging to the technical field of storage batteries. The positive lead paste comprises, by weight, 100 parts of lead powder, 2.5-3.2 parts of red lead, 4.6-5.5 parts of a capacity-increasing stabilizer, 0.2-0.3 parts of nano-carbon fiber, 0.08-0.1 parts of β-naphthol and 12-15 parts of sulfuric acid; the capacity-increasing stabilizer is compounded in the positive lead paste to promote the formation of active tetrabasic lead sulfate on the surface of the capacity-increasing stabilizer, which promotes the improvement of the electrochemical performance of the battery, and the graphene clusters attached thereto provide a large number of ion channels, which are conducive to the deintercalation of ions during the charge and discharge process, and improve the capacity of the battery, and the cluster structure has good toughness, and has a buffering effect on the positive electrode solidified layer during the start-stop high-frequency charge and discharge process, reducing the shedding of the positive electrode coating, so that the battery maintains excellent cycle stability.

The invention relates to the technical field of hard carbon materials, and particularly discloses a hard carbon material and a preparation method and application thereof. Cheap ethylene tar is used as a raw material, a solvent with specific polarity is adopted to carry out three-stage extraction on the ethylene tar, aromatic substances and colloid components with high polarity in the ethylene tar are obtained, the aromatic substances and the colloid components are used as precursors, and the hard carbon material prepared through pre-carbonization and high-temperature carbonization has the large interlayer spacing and can be used for preparing the hard carbon material. The specific capacity, the rate capability and the cycling stability of the sodium-ion battery are favorably improved; in addition, the colloid component can form a cross-linked structure in the hard carbon material, the conductivity and the structural stability of the hard carbon material are improved, and the cross-linked structure can also increase the surface roughness of the hard carbon material and improve the wettability of electrolyte, so that the charge-discharge performance of the sodium ion battery is improved. The hard carbon positive electrode material with low cost and excellent performance is provided for the sodium ion battery, and the purposes of reducing cost and improving efficiency are achieved.

The invention belongs to the technical field of new energy materials, and particularly relates to a secondary battery and electric equipment. Compared with the prior art, by selecting the first active substance and the second active substance with specific compositions and matching with the arrangement of the first coating and the second coating, the energy density of the battery can be improved, and the first coulombic efficiency and the cycle performance can be improved. Specifically, a soft carbon and hard carbon composite material is matched with a graphite coated hard carbon material, so that the energy density can be improved; the first element and the second element are adopted to dope the active substance, so that the conductivity of the negative electrode plate can be improved, the ion diffusion kinetics is improved, and the de-intercalation of sodium ions is facilitated; meanwhile, the arrangement of the double active material coatings is adopted, so that the ion diffusion efficiency can be improved, the de-intercalation of sodium ions is accelerated, the first coulombic efficiency is improved, and the cycle performance of the battery is improved.

The invention discloses a negative active material, a preparation method thereof and a preparation method of a negative pole piece, and relates to the technical field of lithium battery processing. The preparation method comprises the following steps: mechanically grinding and mixing a silicon-carbon negative electrode material and zirconium tungstate, baking in a muffle furnace at a high temperature to obtain a negative electrode active material, mixing the negative electrode active material with a binder, a conductive agent, polydopamine modified carbon fiber and carboxymethyl cellulose according to a mass ratio of 85: 10: 5: (1-3): (0.3-0.8), and coating a copper foil with the mixture to prepare a negative electrode piece; wherein the polydopamine modified carbon fiber comprises a silicon-carbon negative electrode material and a plurality of polymers, carbonizing to obtain a porous carbon fiber coated silicon-carbon negative electrode material, and carrying out dopamine deposition to obtain the polydopamine coated carbon fiber. A lithium battery prepared from the negative electrode active material prepared by the invention shows good first charge-discharge efficiency in a test.

The invention discloses a sodium-ion battery negative electrode material as well as a preparation method and application thereof, and belongs to the field of sodium-ion batteries. The negative electrode material comprises carbon cloth and nanosheets which are mutually interspersed and uniformly dispersed and loaded on the carbon cloth, the nanosheets are cobalt selenide and vanadium selenide, and the nanosheets are of a porous structure; the diameter of the negative electrode material is 10.4-18.6 [mu] m, the thickness of the nanosheet is 10-70 nm, and the aperture of the pores is 3-32 nm; the cobalt selenide accounts for 32.5-48.1% of the mass of the negative electrode material, and the vanadium selenide accounts for 21.4-30.7% of the mass of the negative electrode material. The problem of volume expansion generated in the charge-discharge process can be effectively relieved, active sites for sodium storage are greatly increased, the preparation method is simple in operation step, easy to implement, low in cost, high in charge-discharge rate and excellent in cycle stability, and due to the characteristics, the material has remarkable application potential in industrial production.

The invention provides a lithium ion battery positive electrode active material, a preparation method thereof and a lithium ion battery containing the same. The lithium ion battery positive electrode active material is a composite oxide represented by a general formula LiaNibMncMdNeOf, the composite oxide shows no less than two characteristic peaks under MAS ssNMR, the chemical shift of the characteristic peak 1 is 600-800ppm, the chemical shift of the characteristic peak 2 is-50-50ppm, the integral area of the peak 1 is S1, the integral area of the peak 2 is S2, S1 / S2gt, the integral area of the peak 1 is S1, and the integral area of the peak 2 is S2, S1 / S2gt. The invention also relates to a method. The lithium ion battery positive electrode active material has an excellent layered structure, has a local environment where more lithium ions are located, is beneficial to lithium ion deintercalation, has a lower deintercalation potential barrier, and shows higher discharge capacity and cycling stability compared with the prior art.

The application discloses a preparation method of a closed micropore structure sodium ion battery negative electrode hard carbon material, and comprises the following steps: S1, preparation of a precursor mixed solution: biomass raw material powder and an inorganic acid pore former are used to prepare the precursor mixed solution; S2, carbon precursor drying: the precursor mixed solution is dried to prepare the carbon precursor; S3, pore forming of a closed pore carbon intermediate: the carbon precursor is subjected to high-temperature activation reaction to obtain the closed pore carbon intermediate with a micropore structure after activation; S4, closed pore carbon intermediate refining treatment: the carbon intermediate is crushed and refined, and the refined closed pore carbon intermediate is obtained through sieving; and S5, high-temperature carbonization of the hard carbon material: the refined carbon intermediate obtained in the step S4 is subjected to high-temperature carbonization to obtain the hard carbon material with the closed micropore structure. The application has the characteristics of a green and environment-friendly process, a small specific surface area and excellent electrochemical performance.

The invention provides a preparation method and application of a lithium iron titanate / carbon quantum dot composite material, and belongs to the technical field of electrochemical energy storage. The preparation method comprises the following steps: uniformly mixing anatase and sodium hydroxide, and carrying out ultrasonic treatment and hydrothermal activation; repeatedly centrifuging the activated product sodium titanate and adding deionized water until the supernate is neutral, and drying to obtain a pickling product; the acid pickling product is ground, sieved and calcined to obtain bronze phase TiO2 (B); the preparation method comprises the following steps: by taking citric acid as a chelating agent, dissolving CH3COOLi. 2H2O, FeCl2. 4H2O, TiO2 (B) and carbon quantum dots in absolute ethyl alcohol, carrying out water bath stirring to obtain gel, carrying out vacuum drying and sieving, and calcining in an inert atmosphere to obtain a pre-sintered material; and sequentially carrying out ball milling and sieving on the pre-sintered material, and carrying out final sintering in an inert atmosphere to obtain the Li2FeTiO4 / carbon quantum dot composite material. The carbon quantum dots and the lithium iron titanate are compounded to form the lithium ion battery positive electrode composite material with enhanced electrochemical performance, and the preparation process is simple, low in cost and suitable for large-scale commercial production.

The invention relates to the technical field of sodium ion batteries, and particularly provides a preparation method of a sodium-based Prussian blue material and the sodium-based Prussian blue material. The invention aims to solve the problems that the existing Prussian blue material is cubic, is not favorable for preparing a pole piece by homogenate coating, and influences the performance of a sodium ion battery. The preparation method of the sodium-based Prussian blue material comprises the following steps: S1, providing a mixed solution of potassium ferricyanide, amino acid and an organic reducing agent; s2, enabling the mixed solution in the step S1 to react to generate a potassium-based Prussian blue material; and S3, carrying out sodium ion exchange on the potassium-based Prussian blue material obtained in the step S2 to obtain the sodium-based Prussian blue material. According to the preparation method disclosed by the invention, the sodium-based Prussian blue material which contributes to sodium deintercalation and is good in performance can be prepared, and when the sodium-based Prussian blue material is applied to a sodium ion battery, the performance of the battery can be effectively improved.

The application belongs to the technical field of new energy materials, and particularly relates to a secondary battery and an electric device. Compared with the prior art, the application can improve the energy density of the battery, and improve the first coulomb efficiency and the cycle performance by selecting the first active material and the second active material with a specific composition, and cooperating with the settings of the first coating and the second coating. Specifically, the energy density can be improved by using a soft carbon hard carbon composite material in combination with a graphite coated hard carbon material; the conductivity of the negative electrode sheet can be improved, the ion diffusion dynamics can be improved, and the sodium ion deintercalation can be facilitated by doping the active material with the first element and the second element; and the ion diffusion efficiency can be improved, the sodium ion deintercalation can be accelerated, the first coulomb efficiency can be improved, and the battery cycle performance can be improved by using the settings of the double active material coating.

The present invention provides a sodium ion battery positive electrode material water-based coated electrode and a preparation method and application thereof, wherein the sodium ion battery positive electrode material water-based coated electrode comprises a positive electrode current collector and a positive electrode material layer arranged on the surface of the positive electrode current collector; the slurry used for the positive electrode material layer comprises a positive electrode active material, a conductive agent and a binder. The present invention uses a metal oxide-coated porous graphite and polyaniline layer as the active material in the positive electrode material, wherein the metal oxide presents a hollow structure, which can not only expose more electrochemically active reaction sites, but also improve the charge and discharge efficiency of the sodium battery, and at the same time, the larger specific surface area is conducive to the deintercalation of sodium ions, thereby making the positive electrode material have a higher capacity performance; in addition, the presence of the surface-coated porous graphite and polyaniline can not only limit the volume expansion of the metal oxide, but also effectively improve the conductivity of the metal oxide, thereby improving the cycle performance and rate performance.

The application relates to a polyionic liquid binder suitable for vulcanized polyacrylonitrile and a preparation method and application thereof, which is obtained by carrying out an alkylation reaction and a polymerization reaction on bromo-n-butane and 1-vinylimidazole, and then carrying out an anion exchange reaction on lithium bis(trifluoromethylsulfonyl) imide and sodium anthraquinone-2-sulfonate. The polyionic liquid binder can anchor polysulfide on the polymer chain through the electrostatic interaction between the lone pair electrons in the molecular chain and the polysulfide, effectively inhibits the shuttle effect, contains a quinoid structure which can act as a redox medium to accelerate the electron transfer process and improve the interface kinetic performance of the SPAN positive electrode, has excellent bonding performance and mechanical strength, can significantly improve the structural integrity and electronic conduction continuity of the electrode in the cycle process, and prolongs the cycle life of the electrode. The obtained binder can be widely applied to SPAN-based positive electrodes of lithium ion batteries and provides effective technical support for solving key problems such as volume expansion and poor conductivity of SPAN materials.

The application discloses a preparation method of a regenerated in-situ doped positive electrode material, and comprises the following steps: (1) adding waste lithium ion battery positive electrode material into a mixed solution of 2-hydroxypropionic acid and quinic acid to perform a first reaction; (2) adding a solution of glucosamine and / or aminobutyric acid into the system after the first reaction to perform a second reaction, thereby obtaining a leaching solution rich in valuable metal ions; (3) adjusting the molar ratio of the valuable metal ions and M 2+ , adjusting the pH, and heating and evaporating and concentrating to form a gel; the ionic radius of M 2+ is 1.3-2.0 times the average ionic radius of Ni 2+ , Co 2+ , and Mn 2+ ; (4) performing step-by-step calcination on the gel to obtain a primary regenerated material doped in-situ; and (5) spraying and pyrolyzing the primary regenerated material in a surface treatment agent and then performing low-temperature heat treatment. The application further provides a regenerated in-situ doped positive electrode material.

The application discloses an organic matter intercalated vanadium pentoxide (V2O5) positive electrode composite material and a preparation method and application thereof, and belongs to the technical field of micro-nano materials and electrochemistry. The application uses V2O5 with a wide source as a raw material, and uses bis(4-nitrophenyl) phosphate, diphenyl phosphate, ethyl phosphate and triethyl phosphate as objects to be inserted into adjacent layers of the V2O5 to serve as a support. The application not only improves the interlayer spacing of the V2O5, overcomes the problem that zinc ions are difficult to be deintercalated in the interlayer of the V2O5 in a cycle process, but also improves the structural stability, and improves the capacity and cycle stability.

This application relates to a cathode material and its preparation method, and a lithium-ion battery. The cathode material includes a substrate and at least a coating layer disposed on the surface of the substrate. The general chemical formula of the substrate is formula (I): Li a Ni b Co c N d M 2 e In formula (I) of O2(Ⅰ), N includes Mn and / or Al, M 2 It includes at least one of Zr, Sr, Co, Ba, Y, Ce, Al, Mg, and La; the general chemical formula of the coating layer is shown in formula (II): Li g M 1 (2h‑g) / i O h In equation (II), M 1 Including at least one of Mn, Ti, W, Mo, and Nb; in the diffraction pattern obtained by X-ray diffraction measurement of the cathode material, the cathode material has a diffraction peak 2θ on the (102) plane. 102 The diffraction peak 2θ of the (006) plane 006 The diffraction peak 2θ of the (110) plane 110 The diffraction peak 2θ of the (108) plane 108 ,2θ 102 2θ 006 2θ 110 and 2θ 108 Satisfy the following relationship: 2θ 102 -2θ 006 ≥0.25, 2θ 110 -2θ 108 ≥0.33.

The present invention discloses a solid electrolyte modified by a Schiff base metal nanocomplex and a preparation method thereof; the preparation method comprises the following steps: ball milling the Schiff base metal nanocomplex and the solid electrolyte to obtain a mixed powder, and calcining the mixed powder to obtain a solid electrolyte modified by the Schiff base metal nanocomplex. The present invention introduces a Schiff base nanocomplex into the solid electrolyte to make up for the pores of the solid electrolyte, and at the same time improves the interface contact between the electrodes, providing a continuous channel for lithium ion transmission, thereby improving the electrochemical performance of the all-solid-state battery.

The invention relates to the technical field of battery negative electrode materials, in particular to a zinc vanadate negative electrode material, a preparation method thereof and a lithium ion battery. The preparation method comprises the following steps: dispersing ZnO, Na2CO3 and V2O5 into an organic solvent, and carrying out ball milling treatment to obtain a first mixed solution; the first mixed solution is dried and then cooled to the room temperature, and first powder is obtained; and pressing the first powder into a sheet, and presintering at a first temperature for a first preset time to obtain a first ceramic sheet. The obtained ceramic chip contains a reaction product Na2ZnV2O7 material, Zn / V atoms in the material and surrounding O atoms respectively form Zn / VO4 tetrahedrons, Zn / VO4 tetrahedron layers are alternately arranged along a c axis to form a layered structure, deintercalation of lithium ions is facilitated, and meanwhile, the V element in the material has multiple valence states, so that the material has relatively high gram volume, and the performance of the material is improved. When the negative electrode material is subjected to an electrical test, the negative electrode material shows relatively high gram volume and good cycle performance, and meanwhile, the negative electrode material has the advantages of simple preparation process and cheap and easily available raw materials.

According to the preparation method of the Co2B protective layer coated nitrogen-doped MXene and the application of the Co2B protective layer coated nitrogen-doped MXene in the sodium-ion battery, crystal lattices can be properly changed due to defects generated by nitrogen doping, so that the electrochemical performance of the sodium-ion battery is enhanced. Co2 + is adsorbed through static electricity and Co2B is generated in situ by utilizing rich negative electricity groups on the surface of MXene. By controlling the nitrogen doping process, amorphous Co2B is subjected to crystal transformation under the action of high temperature, and finally N-Ti3C2-coated Co2B is obtained. Nitrogen doping enables MXene to expose more active sites, and Co2B uniformly loaded on the surface can effectively inhibit volume expansion generated in the reaction process. Therefore, the actual electrochemical performance is improved, the rate capability under high cycle specific capacity and large current density is embodied, and the problems of poor cycle performance and low energy density of the sodium ion battery are solved.

The invention relates to the technical field of batteries, and provides a positive electrode material and a preparation method thereof, a positive electrode plate and a secondary battery, the positive electrode material comprises an inner core and a porous coating layer at least coating the surface of the inner core, and the porous coating layer comprises a first coating layer and a second coating layer which are sequentially laminated from the surface far away from the inner core. The structural stability and the cycle performance of the positive electrode material can be improved.

The present invention belongs to the technical field of lithium-ion battery materials, and discloses a positive electrode material and a preparation method and application thereof. The positive electrode material comprises a substrate, a first coating layer and a second coating layer, wherein the first coating layer is coated on at least part of the surface of the substrate, and the second coating layer is coated on at least part of the surface of particles formed by the substrate and the first coating layer; the chemical formula of the substrate is LiNi x Co y Mn 1‑x‑y O2, 0.7≤x<1, 0≤y≤0.2, 0<1‑x‑y≤0.3; the first coating layer is Cr2O3; the second coating layer is NiTiO3, and the positive electrode material is coated and modified by NiTiO3 and Cr2O3, which is beneficial to maintain high capacity and improve the cycle stability of the battery.

The invention provides a sodium manganate-based composite positive electrode material and a preparation method thereof, the positive electrode material comprises sodium manganate, and the sodium manganate is doped with a sodium-containing compound, a metal oxide and a carbon-based material; wherein the sodium manganate, the sodium-containing compound and the metal oxide are all coated with the carbon-based material, the migration rate of sodium ions in the positive electrode material is improved through coating of the carbon-based material, meanwhile, the sodium manganate forms a stable solid solution with the sodium-containing compound and the metal oxide respectively, and dissolution of manganese in the sodium manganate is inhibited. According to the sodium manganate-based composite positive electrode material disclosed by the invention, the sodium-containing compound, the metal oxide and the carbon-based material are compounded with the sodium manganate, so that the first charge-discharge efficiency and the conductivity are improved, and the dissolution of Mn element is inhibited, so that the performance of the sodium manganate composite material is optimal.