9230results about "Nickel compounds" patented technology

The lithium nickel manganese oxide positive electrode material, the preparation method thereof and the electrochemical device are characterized in that the lithium nickel manganese oxide positive electrode material provided by the embodiment of the invention comprises a base material and a coating layer located on the surface of the base material, the general formula of the base material is Li (LiaNixMnyMbO4), the element M comprises at least one of Ti, Zr, Al, Nb and Mo, and a is more than or equal to 0.02 and less than or equal to 0.06; 0.45 < = x < = 0.55, 1.4 < = y < = 1.6; 0.05 < = b < = 0.55; a + x + y + b = 2, and the coating layer contains phosphate. According to the lithium nickel manganese oxide positive electrode material, through doping and coating technologies, under the condition that the capacity is not sacrificed, the gas production phenomenon is effectively reduced, the cycling stability of the lithium nickel manganese oxide positive electrode material is improved, and the service life of an electrochemical device applying the lithium nickel manganese oxide positive electrode material is prolonged.

The invention relates to a surface-modified lithium-rich manganese-based positive electrode material, a preparation method and a lithium ion battery, and the preparation method comprises the following steps: uniformly mixing a lithium-rich manganese-based precursor, a lithium source and a metal oxide required by garnet type solid electrolyte to obtain a mixture; and performing gradient temperature calcination on the mixture in an oxidizing atmosphere to obtain the surface-modified lithium-rich manganese-based positive electrode material, the surface-modified lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based material, a disordered spinel self-protection layer coated on the surface of the lithium-rich manganese-based material, and a garnet type solid electrolyte coated on the surface of the disordered spinel self-protection layer, the gradient temperature calcination comprises the following steps: calcining at the nucleation temperature of the lithium-rich manganese-based material, and then heating to the nucleation temperature of the garnet type solid electrolyte for calcining. The lithium-rich manganese-based positive electrode material can solve the problems of low first coulombic efficiency and poor rate capability of the lithium-rich manganese-based positive electrode material in related technologies.

The invention discloses a method for activating and precipitating MHP through magnesium, and belongs to the technical field of hydrometallurgy. The method comprises the following steps: S1, mixing a magnesium-containing solution with a sodium hydroxide solution, and carrying out precipitation reaction for 3-5 minutes to obtain a precipitator; s2, immediately mixing a precipitator with the laterite-nickel ore iron and aluminum removed liquid, and then carrying out first-stage nickel and cobalt precipitation reaction to obtain first-stage nickel and cobalt precipitation slurry; s3, performing first thickening treatment on the first-section nickel and cobalt deposited slurry to obtain first dense underflow and first dense overflow; and S4, filtering the first dense underflow to obtain an MHP product. According to the method, after the magnesium-containing solution and the sodium hydroxide solution are mixed, the magnesium solution and the sodium hydroxide solution are controlled to be mixed and react for 3-5 min, then the nickel and cobalt precipitation reaction is immediately carried out, the MHP product with high purity and quality can be obtained, and the whole method is simple and convenient for large-scale industrial application.

The invention belongs to the technical field of SERS (Surface Enhanced Raman Scattering) detection, and particularly relates to a preparation method and application of an Ag-coated NiFe2O4 composite SERS substrate. The preparation method comprises the following steps: firstly, preparing Ag nanoparticles which are uniformly distributed and have the same size through a sodium citrate reduction method; secondly, a nanometer flower type NiFe2O4 material is prepared through a hydrothermal method and a calcination method; and finally, the novel SERS substrate Ag-coated NiFe2O4 is prepared through a physical stirring method. The novel SERS substrate made of the Ag nano particles and the nano-flower type NiFe2O4 material is constructed, and compared with a conventional SERS substrate made of independent Ag nano particles, the SERS substrate can detect stronger intrinsic Raman signals of probe molecules. As the SERS substrate needs to be compounded with a nano-flower type NiFe2O4 material during preparation, a charge transfer phenomenon can occur at an interface where the SERS substrate is in contact with probe molecules, so that intrinsic Raman signals of the probe molecules can be enhanced, and the SERS substrate can be better used for detecting and analyzing chemical substances.

The invention provides a sodium-ion battery positive electrode material and a preparation method thereof, a sodium-ion battery and electric equipment, and relates to the field of sodium-ion batteries. The positive electrode material of the sodium ion battery provided by the invention comprises an inner core and a shell, wherein the shell covers the inner core; the chemical formula of the inner core is NaaNixFeyMnzM1-x-y-zO2, wherein a is more than or equal to 0.9 and less than or equal to 1.05, x is more than 0 and less than 1.0, y is more than 0 and less than 1.0, z is more than 0 and less than 1.0, and 1-x-y-z is more than 0 and less than 1; the chemical formula of the shell is NaLarCa1-rO2, wherein r is more than 0 and less than 1; in the inner core, the element M comprises one or more of Al, Mg, Ti, Zr, Y, La, Ca, Zn, Cu, W, Li and B. The sodium-ion battery positive electrode material provided by the invention can reduce residual alkali on the surfaces of particles, can inhibit side reaction with an electrolyte, and improves the performance stability of the positive electrode material.

The invention belongs to but not limited to the technical field of electrode materials, and particularly relates to a high-tap-density lithium nickel manganese oxide positive electrode material, a preparation method and a lithium ion battery, the chemical general formula of the high-tap-density lithium nickel manganese oxide positive electrode material is LiNi < 0.5-x > Mn < 1.5-y > M < x > N < y > O < 4 >, 0.1, 0 < = y < lt >; 0.1, M and N are doping elements and comprise one or more of Mg, Co, Al, Zr, W, Sb, Ta and Ti; the material is micron-sized spherical secondary particles formed by stacking and aggregating nano-sized octahedral primary particles, and is uniformly dispersed without agglomeration; the spherical secondary particles are formed by mixing spherical secondary particles with large and small particle size distribution, and the average particle size range of the large particles is 3lt; d < 50lt >; the average particle size range of the small particles is 1lt; d < 50lt >; 2 [mu] m.

The invention provides a surface interface modified lithium-rich manganese-based positive electrode material and a lithium ion secondary battery. According to the invention, active oxygen substances such as O2, O2-, O-and oxygen polymer On-are absorbed and embedded into lattice gaps from the particle surface interface of the lithium-rich manganese-based positive electrode material under the driving of potential when the functional material is charged to a high voltage, and then the active oxygen is released when the functional material is discharged to a low potential, so that the active oxygen returns to the lithium-rich manganese-based positive electrode material again; and an active oxygen utilization reversible closed loop is formed. In the surface-interface modified lithium-rich manganese-based positive electrode material provided by the invention, the application of the surface functional material inhibits oxidation precipitation of lattice oxygen of the lithium-rich manganese-based positive electrode material in a high-voltage lithium removal state, and the positive electrode material can realize controllable oxygen reversible electrochemical deintercalation / intercalation at different potentials; and the cycling stability and the thermal stability of the material in a high-temperature and high-voltage environment are remarkably improved.

The invention discloses a uniformly radial positive electrode material precursor and a preparation method thereof. The cross section of the uniformly radial positive electrode material precursor is uniformly radial, and the shape of the uniformly radial positive electrode material precursor is divided into a core and an outer layer, the core is loose and porous, and the outer layer is in a regular radial shape; the method adopts a coprecipitation method to carry out two-stage reaction preparation, in the first reaction stage, an inner core layer is prepared; a second reaction stage: preparing a shell layer to reach a target particle size; the secondary particle D50 is 6.0-14.0 microns, the TD is greater than 1.90 g / cm, and the BET is less than or equal to 14m < 2 > / g; the precursor is small in structure core and compact in outer layer, particles grow in a radial mode from inside to outside, lithium ions can be separated and embedded out easily, the particle structure is more stable, and excellent rate performance and cycling stability are shown; a staged coprecipitation method is adopted, and controllable growth of a particle structure is realized by accurately controlling the ratio of oxygen to nitrogen and reaction conditions; according to the whole process design, the complex parameter adjusting range is reduced, and the production stability and repeatability are improved.

The invention provides a lithium-rich manganese-based positive electrode active material and a preparation method and application thereof. The lithium-rich manganese-based positive electrode active material comprises a lithium-rich manganese-based core, a first coating layer and a second coating layer, the chemical formula of the lithium-rich manganese-based core is Li < 1 + x > Ni Mn M < c > O < 2 + x >; 0.25 < = x < = 0.4, a + b + c = 1, 0.33 < = a < = 0.35, 0.63 < = b < = 0.65, and 0 < = c < = 0.02; m is selected from at least one of W, Ta, Nb, Ti, Sb, Al, Mg, Zr, Sr and Mo; the first coating layer is X-doped nano layered lithium cobalt oxide, and X is selected from at least two of Al, La, Nb, Sr, Ti, Mn, Mo, Ta, W, K, B and F; and the second coating layer comprises a fast ion conductor and / or a spinel-like phase cobalt lithium compound. The positive electrode active material provided by the invention has excellent storage capacity.

The invention provides an in-situ modified lithium-rich manganese-based precursor and a preparation method and application thereof.The preparation method comprises the following steps that a nickel-cobalt-manganese mixed metal salt solution, a precipitator solution and a complexing agent solution are introduced into a base solution for a first coprecipitation reaction, and after the first coprecipitation reaction is finished, feeding is stopped; and introducing a doped nickel-cobalt-manganese mixed metal salt solution, a precipitant solution, a complexing agent solution and a carbon source solution into a system after the first coprecipitation reaction is finished, and carrying out a second coprecipitation reaction to obtain the in-situ modified lithium-rich manganese-based precursor. According to the preparation method, doping elements and a carbon source are introduced when the lithium-rich manganese-based precursor is prepared through the coprecipitation reaction, in-situ uniform construction of oxygen vacancies and a carbon coating layer on the surface of the material is synchronously achieved, the in-situ modified lithium-rich manganese-based precursor is obtained, the treatment step of subsequent secondary coating can be reduced, the production cost can be reduced, and the method is suitable for industrial production. The technological process is shortened.

The invention discloses a molybdenum disulfide and lithium-lanthanum-niobium-oxygen co-coated lithium-rich manganese-based positive electrode material and a preparation method thereof, and realizes double uniform coating of molybdenum disulfide and lithium-lanthanum-niobium-oxygen on the surface of the lithium-rich manganese-based positive electrode material by combining freeze drying and calcining technologies. The double coating layer not only can be used as a stable protective layer to prevent the positive electrode material from being eroded, but also can form a stable coating structure by utilizing the physical and electrochemical compatibility between two adjacent elements of molybdenum and niobium in the same period, so that the electrochemical performance is optimized, the'deoxidation 'phenomenon is avoided, and the service life of the positive electrode material is prolonged. Under co-coating of the molybdenum disulfide and the lithium lanthanum niobium oxide, the lithium-rich manganese-based positive electrode material co-coated with the molybdenum disulfide and the lithium lanthanum niobium oxide is obtained, and the lithium-rich manganese-based positive electrode material co-coated with the molybdenum disulfide and the lithium lanthanum niobium oxide can guarantee the first effect and the specific capacity of the battery and can fully optimize the cycle performance of the battery.

The invention belongs to the technical field of energy storage materials, and particularly relates to a high-entropy oxide Fe0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2O and an ultrafast synthesis method and application thereof. According to the preparation method, ferroferric oxide, cobalt oxide, nickel oxide, copper oxide and zinc oxide with equal molar ratio are adopted as direct synthesis raw materials, toxic gases such as chlorine and nitrogen dioxide generated in the synthesis process of a metal salt precursor are avoided, and the uniformly distributed single-phase high-entropy oxide is synthesized in an ultrafast manner within 10 seconds by using a Joule heating technology; the synthesized high-entropy oxide is used as a lithium ion battery negative electrode material, and shows more excellent electrochemical performance and cycling stability compared with other high-entropy oxides prepared from transition metals with different proportions; in the preparation process, extra additives are not needed, operation is easy, the synthesis speed is high, the yield is high, element distribution is uniform, and the method has the advantages of being low in cost, high in efficiency and free of pollution and has the industrialization prospect.

The invention relates to the technical field of wave-absorbing materials. Specifically, the invention relates to a ferrite composite multi-walled carbon nanotube wave-absorbing material and a preparation method thereof. The invention also relates to electronic equipment containing the ferrite composite multi-walled carbon nanotube wave-absorbing material. The ferrite composite multi-walled carbon nanotube wave-absorbing material prepared by the invention comprises a ferrite magnetic material with magnetic loss and a multi-walled carbon nanotube material with electrical loss, and the composite material introduces multiple electromagnetic energy loss modes through unique structural design and component synergy, so that the wave-absorbing performance of the material is enhanced. In addition, the preparation method disclosed by the invention is simple in process, low in requirement on equipment, green and environment-friendly, and free from any toxic and harmful by-products.

The invention discloses a high-nickel ternary positive electrode material as well as a preparation method and application thereof. The chemical formula of the positive electrode material is LixNiyCozMaNbOc, M is at least one of Mn and Al, N is at least one of Ti, V, Nb, Zr, Ta, W or Mo, x is larger than or equal to 0.9 and smaller than 1.2, y is larger than or equal to 0.6 and smaller than or equal to 0.95, 0 lt, and z is larger than or equal to 0.5. Z < = 0.2, 0lt; a < = 0.2, 0 < b < = 0.02, and values of x, y, z, a, b and c accord with an electrically neutral principle; the positive electrode material has a single crystal morphology, the average size of primary particles is 0.20-1.50 microns, and the c / a ratio in lattice parameters is greater than 4.9360. The positive electrode material is applied to a positive electrode of a lithium ion battery, and shows good first coulombic efficiency and charge-discharge capacity.

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 provides a ternary precursor and a preparation method thereof, a positive electrode material and a preparation process thereof, and a battery. The ternary precursor comprises an inner core, and a transition layer and a shell which are sequentially coated outside the inner core, the nickel content of the inner core is gt; the nickel content of the transition layer is gt; and the nickel content of the shell. The inner core in the ternary precursor has the highest nickel content, so that the capacity of the positive electrode material prepared from the ternary precursor is ensured; the nickel contents of the inner core, the transition layer and the shell are changed in a gradient manner, so that the thermal stability of the ternary precursor is improved; the shell reduces the interface side reaction between the positive electrode material prepared from the ternary precursor and an electrolyte; the transition layer can be used as a buffer layer between the inner core and the shell, so that the ternary precursor and the structural stability are improved. Therefore, the battery containing the positive electrode material prepared from the ternary precursor has excellent capacity and cycling stability at normal temperature and high temperature.

The invention discloses a lithium ion battery positive electrode material and a preparation method thereof, the lithium ion battery positive electrode material comprises an active substance, a conductive additive, a binder and a thermal stability additive, the active substance is # imgabs0 # with a layered structure, x + y + z = 1, 0.5 < = x < = 0.8, 0.1 < = y < = 0.3, 0.1 < = z < = 0.3, the conductive additive is a compound of a carbon nanotube and graphene, and the thermal stability additive is a mixture of a carbon nanotube and graphene. The binder is a mixture of polyvinylidene fluoride and sodium carboxymethyl cellulose, the thermal stability additive is a mixture of lithium phosphate and aluminum oxide, the sum of the mass fraction of the lithium phosphate and the mass fraction of the aluminum oxide in the thermal stability additive is 0.5-10%, and the mass fraction of the lithium phosphate is 0.5-5%. According to the lithium ion battery positive electrode material and the preparation method thereof, the stability of the positive electrode material at high temperature can be improved, the thermal runaway risk is reduced, and the cycle life of the battery is prolonged.

The invention provides a positive active material and a preparation method thereof, a positive plate and a battery. The positive electrode active material satisfies the following condition: # imgabs0 #, wherein I (111), I (222), I (400) and I (440) are all not 0. According to the positive electrode active material provided by the invention, the exposure degrees of the crystal face (222) and the crystal face (111) relative to the crystal face (110) and the crystal face (100) are limited by the formula 1, so that the lithium ion conduction rate and the dynamic performance of lithium nickel manganese oxide can be improved, and the rate capability and the discharge capacity of a corresponding battery can be remarkably improved.

The invention relates to the technical field of lithium batteries, in particular to a preparation method of a regenerated high-nickel ternary material, and the preparation method comprises the following steps: classifying, discharging, disassembling and sorting a waste ternary lithium battery to obtain a ternary waste material; the ternary waste is subjected to pyrolysis treatment, ultrasonic treatment, sieving, smashing and sieving, and ternary waste fine powder is obtained; performing element determination on the ternary waste fine powder, then adding a nickel source, a cobalt source, a manganese source and a lithium source, adjusting the molar ratio of metal elements, and fully stirring and mixing to obtain a mixture; and sintering the mixture twice, crushing, screening and demagnetizing to obtain the regenerated high-nickel ternary material. The preparation method is simple to operate, acid-base leaching and extraction recovery are not involved in the whole process, harmful substances are not generated, and secondary pollution to the environment is avoided.

Provided in the present application are a lithium-rich manganese-based precursor material, and a preparation method therefor and the use thereof. The preparation method comprises the following steps: in a protective gas atmosphere, mixing a nickel-cobalt-manganese mixed salt solution, a precipitator solution and a complexing agent solution, subjecting same to a co-precipitation reaction until particles enter a growth stage, starting the introduction of an oxygen-containing gas, and then continuously subjecting same to the co-precipitation reaction, so as to obtain a lithium-rich manganese-based precursor material. In the preparation method of the present application, by introducing the oxidizing atmosphere in the growth stage of the precursor material, the problems of compact particle growth, being prone to agglomerating and poor morphology in the existing preparation process for a lithium-rich manganese precursor material are solved, and a lithium-rich manganese-based precursor material having high dispersity and a high specific surface area is obtained.

Disclosed are high-entropy oxides, and methods of their preparation. The high-entropy oxide is characterised by a sub-micron particle size and rod-like particle shape. The method of its preparation includes a co-precipitation step, preferably using an oxalate compound as a precipitating agent. Also disclosed are an electrode, e.g. an anode, a catalyst and an electrochemical cell comprising the high-entropy oxide.

The invention provides a coated modified high-nickel ternary positive electrode material, a preparation method and a lithium ion battery, the coated modified high-nickel ternary positive electrode material comprises a high-nickel ternary matrix and a coating layer containing an oxide solid electrolyte, the coating layer is coated outside the high-nickel ternary matrix and accounts for 1%-3% of the mass of the high-nickel ternary matrix; the oxide solid electrolyte comprises Li < 3x > La < 2 / 3-x > TiO < 3 > (0 lt; x < = 0.16), Li < 7 > La < 3 > Zr < 2 > O < 12 >, Li < 1 + y > Al < y > Ti < 2-y > (PO < 4 >) < 3 > (0 lt; y < = 0.5); the ionic conductivity of the oxide solid electrolyte is greater than or equal to 1 * 10 <-4 > S / cm. The selected oxide solid electrolyte has high ionic conductivity and electronic insulativity, a rapid lithium ion transmission channel can be provided, interface side reaction can be inhibited, the rate capability and the cycling stability of the material can be remarkably improved, and when the oxide solid electrolyte forms a coating layer, the coating layer is not prone to deformation, and the service life of the material is prolonged. The interface bonding strength with a high-nickel ternary matrix can be improved through chemical bonding, the interface impedance can be remarkably reduced, and the dynamic performance of the material is improved.

Provided in the present disclosure are a positive electrode material precursor, a preparation method therefor, and the use thereof. The preparation method comprises: mixing a glycine buffer solution containing ethylene glycol with a metal source, and reacting same to obtain the positive electrode material precursor. The present disclosure uses the glycine buffer solution as a reaction substrate solution, and adds the metal source to same for reaction, thereby keeping the pH of the system stable, and improving the uniformity and purity of the metal element. In addition, by means of a synergistic effect between glycine and ethylene glycol, interfacial energy of different crystal planes of the precursor particles can be effectively regulated, thereby regulating the growth and arrangement modes of the precursor particles to enable precipitated particles to preferentially grow in the orientation of (003) crystal planes, so as to obtain elongated strip-shaped primary particles, which can provide a rapid diffusion channel for lithium ions, reduces the diffusion resistance of Li+ and improves the orderliness of the crystal structure, thereby improving the rate capability and the cycling stability of the positive electrode material.

The invention relates to a secondary battery, a positive active material, a preparation method of the positive active material, a positive pole piece and an electric device. The secondary battery comprises a positive pole piece, the positive pole piece comprises a positive active layer, and the positive active layer comprises a positive active material; in a particle size distribution curve of primary particles in the positive electrode active material, the half-peak width is marked as WH, and WH is less than or equal to 2.5 microns; the average particle diameter D1 of the primary particles in the positive electrode active material satisfies 1.3 [mu] m < = D1 < = 3 [mu] m. The battery life of the secondary battery at a high voltage is significantly improved.

The invention discloses a nickel-containing etching wastewater treatment process, which belongs to the technical field of environmental protection, and comprises a raw water regulating tank, a pH pre-regulating tank, a heterogeneous catalytic oxidation tower, a neutralization coagulation tank, an inclined tube sedimentation tank and a clean water tank which are connected in sequence. According to the process, under the neutral condition, a catalyst loaded with cobalt manganese oxide is used for activating sodium hydrogen persulfate, high-activity sulfate free radicals are generated, a Ni-EDTA complex structure is fractured in a targeted mode, free nickel ions are released in situ, organic ligands are synchronously mineralized, and the adding amount of sodium hydrogen persulfate is dynamically adjusted through a clean water pool closed-loop control system; and high-purity nickel hydroxide precipitate is generated through alkaline precipitation and coagulation, so that efficient solid-liquid separation is realized. The treatment process disclosed by the invention is compact in flow and stable in operation, effectively solves the problems of difficult complex breaking, low nickel removal efficiency, high sludge toxicity, difficult resource recovery and the like when the EDTA complex nickel wastewater is treated by a traditional method, realizes closed-loop recovery of nickel resources, and has the remarkable advantages of low cost, high efficiency and environmental friendliness.

The invention discloses a lithium-rich manganese-based positive electrode material with a core-shell structure, the general formula of the lithium-rich manganese-based positive electrode material is Li < 1 + a > Mn < x > Co < y > Ni < z > O < 2-b-d > (XOc) X < d >, the lithium-rich manganese-based positive electrode material has the core-shell structure, the core is a lithium-rich manganese-based material Li < 1 + a > Mn < x > Co < y > Ni < z > O < 2-b > (XOc) doped with disordered polyanions, and the shell is a lithium-rich manganese-based material Li < 1 + a > Mn < x > Co < y > Ni < z > O < 2-d > X < d > doped with gradient non-metal ions. The invention also provides a preparation method of the lithium-rich manganese-based positive electrode material with the core-shell structure, and the lithium-rich manganese-based positive electrode material with the core-shell structure is prepared by adopting a combined means of rapid Joule heat treatment and surface plasma cleaning treatment. The polyanion-doped bulk phase disordered structure design and the surface gradient non-metal ion-doped core-shell structure are realized. Wherein the bulk phase polyanions can fix transition metal elements to inhibit migration of the transition metal elements to a lithium layer, harmful consumption of active sites is reduced, and a lattice structure is stabilized. In addition, strong bond energy between surface nonmetal and transition metal elements can inhibit dissolution of transition metal in the circulation process, irreversible oxidation of oxygen is reduced, and generation of harmful phase change is inhibited.

The invention provides a high-stability lithium-rich manganese-based positive electrode material and a preparation method thereof, and relates to the technical field of lithium-rich manganese-based positive electrode materials, and the method comprises three steps of preparation of a homogeneous precursor, solid-state mechanical fusion doping and coating, and high-temperature sintering; a lithium-rich manganese-based precursor is prepared by adopting a homogeneous coprecipitation process, uniform distribution of metal ions is ensured, then an aluminum source, a zirconium source and a fluorine source are introduced as doping agents, phosphate and a titanate coating agent are combined, doping and coating integrated treatment is realized through mechanical ball milling, and the lithium-rich manganese-based composite material is obtained. And finally, mixing with a lithium source in an argon atmosphere, and carrying out high-temperature sintering of temperature programming and staged heat preservation to form a stable composite coating layer in situ. Therefore, manganese ion migration is effectively inhibited through lattice doping, a layered structure is prevented from being converted into spinel or rock salt phase, meanwhile, a nanoscale ion / electron transmission channel is constructed, interface impedance is reduced, and the charging and discharging efficiency under high voltage is improved.

The invention discloses a positive electrode material and a preparation method thereof, a positive electrode, a sodium battery and an electric device. The positive electrode material comprises a layered oxide represented by a chemical formula NaaNibFecMndMeOf, wherein 0.8 < = a < = 1, 0 < = b < = 0.2, 0.25 < = c < = 0.5, 0.26 < = d < = 0.6, 0 < = e < = 0.1, and 1.8 < = f < = 2; m is a doped metal element. The preparation method of the positive electrode material comprises the step of carrying out sintering treatment on a NaaNibFecMndMeOf precursor. The positive electrode contains the layered oxide shown in the chemical formula, and the sodium battery contains the positive electrode. The electric device comprises the sodium battery. The layered oxide contained in the positive electrode material is high in structural stability, gram volume and energy density and good in cyclicity. The sodium battery is high in energy density and good in cycle performance.

The invention provides a ternary positive electrode material and a preparation method thereof, a positive electrode and a battery, and is applied to the field of batteries, the ternary positive electrode material comprises a self-supporting micro-cage structure, the material of the micro-cage structure is a high-nickel ternary material, the micro-cage structure is internally provided with a cavity, and part of the cavity in the micro-cage structure is filled with a conductive agent. A cavity is formed in the micro-cage structure and can allow lithium ions to enter and exit. Through the structural design, the volume expansion or shrinkage of the high-nickel ternary material in the charging and discharging process can be effectively inhibited, the structural change of the material is reduced, the stability of the high-nickel ternary material is improved, and the cycle performance of the battery is further improved.

The invention provides a bio-based carbon material modified ternary precursor and a preparation method and application thereof.The preparation method comprises the following steps that 1, a nickel-cobalt-manganese mixed salt solution, a complexing agent, a precipitator and a doped metal source solution are injected into a base solution in a parallel flow mode to be subjected to a co-precipitation reaction, and an inner core solution is obtained; (2) adjusting the solid content of the inner core solution and the concentration of a complexing agent, injecting a nickel-cobalt-manganese mixed salt solution, the complexing agent, a precipitator and a doped metal source solution in a parallel flow manner, and carrying out a second coprecipitation reaction to obtain a doped ternary precursor; and (3) carbonizing a bio-based carbon source, mixing the carbonized bio-based carbon source with the doped ternary precursor, and sintering to obtain the bio-based carbon material modified ternary precursor. Doping elements in the ternary precursor effectively permeate into a matrix for doping, and a coating layer prepared from the bio-based carbon material is high in stability and good in rate capability.