153 results about "Oxide cathode" patented technology

The invention relates to the technical field of sodium ion battery positive electrode materials, in particular to a boric acid modified ternary layered oxide positive electrode material and a preparation method and application thereof. The chemical general formula of the boric acid modified ternary layered oxide positive electrode material is Na2 / 3Ni1 / 3Co1 / 3Mn1 / 3BxO, and x is more than 0 and less than or equal to 0.09; the boric acid modified ternary layered oxide positive electrode material is subjected to boric acid modification treatment and comprises interstitial doping of boron elements and a surface BO coating layer, the interstitial doped boron elements are located at tetrahedral sites of a transition metal layer, and the thickness of the BO coating layer is 3 nm to 10 nm. The boric acid modified ternary layered oxide positive electrode material prepared by the invention shows high specific capacity, good cycling stability and excellent rate capability in the sodium ion battery, and meanwhile, the preparation method disclosed by the invention has the advantages of simple preparation process, high cost effectiveness and the like, and has a wide application prospect.

The invention belongs to the technical field of electrochemical energy storage, and discloses a method for reducing residual alkali on the surface of a layered oxide positive electrode material and application of the layered oxide positive electrode material in a sodium ion battery, the chemical general formula of the layered oxide positive electrode material is NaxNiaMnbMcO2, wherein M is a mixture of more than one of Li < + >, K < + >, Mg < 2 + >, Ca < 2 + >, Ti < 4 + >, V < 3 + >, V < 4 + >, Cr < 3 + >, Fe < 3 + >, Co < 3 + >, Cu < 2 + > and Zn < 2 + >. X, a, b and c are molar ratios of corresponding elements respectively, and x is more than or equal to 0.6 and less than or equal to 1.0, 0lt; a is less than or equal to 0.5, 0.2 lt; b < = 0.7, 0 < = clt; 0.3 and a + b + c = 1; all the components meet charge conservation and stoichiometric conservation. The preparation method comprises the step of carrying out secondary sintering on the layered oxide positive electrode material synthesized by primary sintering in a specific atmosphere. The preparation process is simple, and a simple, convenient and easy-to-implement large-scale industrial production solution is provided.

The invention relates to the technical field of sodium ion batteries, in particular to a composite sodium ion positive electrode material, a preparation method thereof, a positive electrode plate and a sodium ion battery. The general formula of the composite sodium ion positive electrode material is Na < x > MO < 2-alpha > Na Fe V < c > Md (PO4) e (P2O7) f (SO4) g Nh, the NaxMO2 comprises an O3-phase layered oxide positive electrode material and / or a P2-phase oxide positive electrode material; and NaaFebVcAd (PO4) e (P2O7) f (SO4) gGh is a polyanion material. According to the composite sodium ion positive electrode material, the phenomena of particle crushing and pole piece brittle failure caused by excessive extrusion of layered oxide particles in the pole piece rolling process can be effectively relieved, and meanwhile, the phenomenon of particle cracking caused by interlayer slippage after long circulation can be inhibited.

The invention belongs to the technical field of sodium-ion battery positive electrode material preparation, and particularly discloses a double-modified sodium-ion battery layered oxide positive electrode material and a preparation method thereof, and the preparation method comprises the following steps: S1, synthesizing a P2-type sodium-ion battery nickel-manganese-based layered oxide by using a high-temperature solid-phase method; s2, uniformly mixing two or more of lithium fluoride, sodium fluoride, calcium fluoride or magnesium fluoride in proportion to prepare a multi-element fluoride coating material; and S3, uniformly mixing the P2-type sodium-ion battery nickel-manganese-based layered oxide and the multi-fluoride coating material according to a ratio, and then carrying out high-temperature quenching treatment to obtain the surface fluoride-coated and near-bulk-phase-doped dual-modified sodium-ion battery layered oxide positive electrode material. According to the dual-modified layered oxide positive electrode material for the sodium-ion battery and the preparation method, surface fluoride coating and near bulk phase doping are cooperatively utilized, so that the high-voltage cycle performance of the layered oxide positive electrode material for the sodium-ion battery is improved.

The invention relates to the technical field of sodium ion batteries, in particular to an MOF-coated layered oxide positive electrode material, a preparation method thereof and a sodium ion battery. The preparation method comprises the following steps: ball-milling and mixing a metal source and a sodium source, and calcining to obtain a layered oxide positive electrode material; the preparation method comprises the following steps: adding Mn salt or Al salt and 2, 5-dihydroxy terephthalic acid into a mixed solvent composed of dimethyl amide, ethanol and deionized water, stirring, and reacting to obtain an MOF material; and mixing the layered oxide positive electrode material and the MOF material, and carrying out heat treatment to obtain the MOF-coated layered oxide positive electrode material. The MOF serving as a coating layer material has a large-aperture structure, a diffusion channel is provided for sodium ion transmission, and the migration rate of sodium ions is increased; mn-MOF or Al-MOF is used as a coating layer material, so that the surface oxygen defect concentration of the layered oxide positive electrode material can be adjusted, the reversibility of oxidation reduction of oxygen anions can be improved, and the coulombic efficiency and the cycling stability of the battery during charging and discharging under a high-voltage condition can be further improved.

Some embodiments are directed to systems and methods for direct recycling of batteries. In one aspect, a method includes obtaining spent cathode materials from spent batteries. The method includes wet milling the spent cathode materials in an aqueous medium to obtain deagglomerated particles. The method includes spray drying the deagglomerated particles to obtain a plurality of clusters of particles. The method further includes annealing the plurality of clusters of particles in a gaseous environment to obtain a plurality of single particles.

The present disclosure provides the methods for preparing nickel-rich hydroxide precursor material and nickel-rich oxide cathode material having a homogeneous structure with an element concentration-gradient distribution by utilizing a continuous Taylor-flow reactor, comprising: (1) preparing an aqueous solution A with metal ion raw materials dissolved therein, an aqueous solution B with a manganese source dissolved therein, an aqueous solution C with a precipitant dissolved therein, and an aqueous solution D with a chelating agent dissolved therein; feeding the aqueous solution A, the aqueous solution C and the aqueous solution D into the continuous Taylor-flow reactor to perform a first co-precipitation reaction; (2) feeding the aqueous solution B into the continuous Taylor-flow reactor to perform a second co-precipitation reaction; (3) washing the precipitate obtained from the second co-precipitation reaction and putting the precipitate into an oven to dry the precipitate to fabricate the nickel-rich hydroxide precursor material. The nickel-rich hydroxide precursor material prepared with the method of the present disclosure exhibiting an element gradient distribution with the nickel-rich inner layer and the manganese-rich outer layer may reduce the diffusion impedance of the lithium ions and increase their migration paths, and the nickel-rich oxide cathode material prepared from the nickel-rich hydroxide precursor material may increase the electrochemical performances and mechanical stability of the lithium-ion cells, such as charging and discharging rate, long-term cycle life, etc.

The invention provides a composite sodium ion battery layered oxide positive electrode material and a preparation method thereof, the positive electrode material comprises an O3 type core layer material and a P2 type shell layer material, the chemical formula of the O3 type core layer material is NahNiiMnjFekZr1-i-j-kO2, 0.95 < = h < = 1.15, 0.25 < = i < = 0.4, 0.25 < = j < = 0.4, 0.25 < = k < = 0.4, 0.05 < = 1-i-j-k < = 0.15. The chemical formula of the P2 type shell layer material is Na < 0.7 > Ni < 0.37-p > Mg Mn < 0.63-q-r > Ti < q > Sn < r > O2, p is greater than or equal to 0.01 and less than or equal to 0.07, q is greater than or equal to 0.01 and less than or equal to 0.15, and r is greater than or equal to 0.01 and less than or equal to High charge-discharge specific capacity is provided through the O3 type core layer material, good air stability is provided through the P2 type shell layer material, and the cycle stability of the core layer material is improved by doping the zirconium element in the O3 type core layer material; by doping magnesium, titanium and tin elements in the P2 type shell material, the complex phase change of the shell material in the charge-discharge cycle process is inhibited, and the cycle stability of the shell material is improved, so that the positive electrode material has high charge-discharge specific capacity and keeps good air stability and high cycle stability at the same time.

The invention discloses a preparation method for recycling and regenerating a Zn-doped manganese-sodium-rich electrical ternary positive electrode material from a waste nickel cobalt lithium manganate positive electrode. The Zn-doped sodium ion layered transition metal oxide positive electrode material is regenerated and prepared through the processes of acid leaching, coprecipitation and calcination. Related test results show that the regenerated Zn-doped layered nickel-cobalt-manganese oxide manganese-rich sodium battery positive electrode material shows relatively excellent sodium storage performance. According to the method, the recycling process is simplified, the waste power battery is taken as a raw material, valuable components are recycled, and the cycle performance of the layered transition metal oxide positive electrode material of the regenerated sodium ion battery is improved through Zn doping. According to the recovery method, high-value utilization of waste resources is realized; and meanwhile, the cycle performance of the layered transition metal oxide positive electrode material of the regenerated sodium-ion battery is improved by doping simple metal elements. The preparation process is simple, high in operability, wide in raw material source, low in cost and suitable for large-scale production, and meets environmental requirements.

The invention discloses an element doped and modified lithium-rich manganese-based layered oxide positive electrode material and a preparation method thereof, the chemical formula of the element doped and modified lithium-rich manganese-based layered oxide positive electrode material is Li < 1.2 > (Mn < 0.54 > Ni < 0.13 > Co < 0.13 >) < 1-x-y > Nb < x > B < y > O < 2 >, x is equal to 0.01-0.02, and y is equal to 0.01-0.02. According to the positive electrode material prepared by the invention, multi-element doping of niobium and boron is adopted, and the stability of a bulk phase and a surface crystal structure of the lithium-rich manganese-based layered oxide positive electrode material is improved by optimizing raw materials, element contents and process parameters, so that surface side reaction under high voltage is inhibited, and meanwhile, the ionic conductivity and the electronic conductivity of the material are greatly improved; and the high-voltage fast charging performance and the high-voltage cycling stability of the lithium-rich manganese-based layered oxide positive electrode material are obviously improved.

In an anode and cathode synergistic electrocatalytic system for wastewater treatment and an application, an electrode having a “dual function” is used as a cathode. The cathode and an anode are sequentially arranged in a crisscrossed and parallel mode and fixed into an electrode group. The electrode group is paced in a reaction tank which has an aeration device at the bottom thereof, separately connecting the cathode and the anode of the electrode group to a power supply. Electrocatalytic degradation is performed on wastewater. In the electrocatalytic degradation process, a synergistic electrocatalytic degradation effect of the anode and the cathode is achieved by the mutual coordination of heterogeneous electro-fenton of the cathode and oxidation of the anode. The cathode ad anode synergistic electrocatalytic process has a good wastewater treatment effect, high current efficiency, low energy consumption, and low operation and maintenance costs.

The application discloses a synthesis method of a large single-crystal sodium-ion battery layered oxide positive electrode material, and comprises the following steps: (1) weighing metal oxides containing transition metal elements, transferring to a device with mixing functions, uniformly mixing, and obtaining a metal oxide mixture; (2) adding acid to the metal oxide mixture, fully mixing, and completing an acid treatment process; (3) adding alkali to the mixture after acid treatment, fully mixing; (4) transferring the mixture obtained in the step (3) to a calcining furnace, high-temperature calcining, and obtaining a layered oxide. The acid treatment process is introduced, the surface of the metal oxide forms a defect structure under the action of the acid, and the defect structure is more beneficial to the formation of strong interaction between each component of the metal oxide and between the metal oxide and sodium-containing alkali, so that a larger single-crystal layered oxide structure is finally formed, and the specific capacity, rate performance and cycle performance are excellent.

Disclosed herein are methods of preparing lithium transition metal oxide cathode materials for secondary batteries and other applications from elemental feedstocks and products thereof. The methods disclosed herein may include mixing at least one transition metal in elemental form with a lithium source in a dry solid state mixing process followed by a sintering step to form a lithium transition metal oxide cathode material.

The application belongs to the technical field of lithium ion batteries, and particularly relates to a kind of one-dimensional LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 ternary layered oxide positive electrode material and a preparation method thereof, which comprises the following steps: adding a nickel salt, a cobalt salt and a manganese salt into water, stirring and dissolving to obtain a solution A; adding LiMn2O4 into the solution A and stirring uniformly to obtain a solution B; mixing a lithium salt with water to obtain a solution C, and under stirring, adding the solution C into the solution B to obtain a solution D; evaporating the solution D under stirring to obtain a precursor powder; and sintering the precursor powder at 400-600 DEG C, and then sintering at 750-850 DEG C to obtain the positive electrode material. 1 / 3 Co 1 / 3 Mn 1 / 3 O2 material.

This invention belongs to the technical field of sodium-ion battery electrode materials, specifically relating to a preparation method and application of an air-stable molten asphalt-coated sodium selenide composite cathode sodium replenisher. The invention first prepares pure-phase sodium selenide nanoparticles in a glove box by room temperature stirring. Then, asphalt is grown in situ on the surface of the sodium selenide through ball milling and high-temperature calcination, thereby forming a core-shell structured sodium selenide composite sodium replenisher material coated with molten asphalt. The resulting composite sodium replenisher is stable in air for extended periods without deterioration, while simultaneously reducing the decomposition potential of sodium selenide and improving its decomposition efficiency. Coupled with a layered oxide cathode, it can achieve cathode sodium replenishment, compensating for the loss of active sodium caused by the growth of the SEI film on the surface of the hard carbon anode. Furthermore, its decomposition product, selenium, can inhibit the lattice oxygen evolution of the layered oxide cathode, improving the structural stability of the cathode and thus effectively enhancing the battery's initial efficiency and cycle performance, demonstrating promising commercial application prospects.

This invention provides a P2-type nickel-manganese base-based oxide cathode material for sodium-ion batteries and its preparation method. It relates to the field of sodium-ion battery material preparation and is prepared via a simple solid-state method, suppressing the formation of Na+. + This cathode material improves cycle stability based on a vacancy-ordered structure using Ti. 4+ Doping stabilizes the material structure and suppresses the deterioration of cycle performance caused by undesirable phase transitions under high pressure. Its chemical formula is Na. 0.67 Ni 0.18 Mg 0.1 Cu 0.05 Mn 0.67‑x Ti x O2 (0≤x≤0.2), the preparation method of this invention is simple, the prepared material has good cycle performance, and it has a good application prospect in the cathode material of sodium-ion batteries.

This invention discloses a monocrystalline cathode material for sodium-ion batteries, its preparation method, and its applications. The preparation method of this monocrystalline cathode material includes the following steps: mixing and sintering waste materials and / or precursor materials with molten salt to obtain a molten salt sintered product; washing the molten salt sintered product with a salt solution, followed by filtration and drying to obtain the monocrystalline cathode material for sodium-ion batteries. This invention is based on molten salt technology, introducing salt solution washing during the washing stage. Based on solvation structure regulation, it inhibits the damage of water molecules to the oxide cathode material, thereby achieving the cleaning of excess molten salt while maintaining the structural integrity of the newly prepared material. The method of this invention has the characteristics of low cost, simple process, and wide applicability. It can realize the unified recycling of waste materials in different states or the direct sodium intercalation of precursor materials, providing technical support for the closed-loop development of the sodium-ion battery industry.

This invention discloses an O3-phase high-entropy layered oxide cathode material, its preparation method, and its application, belonging to the technical field of sodium-ion battery cathode materials. The O3-phase high-entropy layered oxide cathode material has the chemical formula NaNi. 1‑ 8x Ca x Co x Al x Fe x Mn x Si x Ti x Zr x O2, x = 0.05~0.1. Raw materials are weighed according to stoichiometric ratio, mixed, and pulverized to obtain precursor powder. The precursor powder is then sintered in a pure oxygen atmosphere to obtain a first sintered product, which is then pulverized again. The pulverized product is then sintered in a pure oxygen atmosphere for a second step, and after cooling, an O3 phase high-entropy layered oxide cathode material is obtained. Sodium-ion batteries assembled based on this cathode material exhibit excellent high-rate performance and long-cycle stability.

This invention belongs to the field of sodium-ion battery material technology, specifically relating to a multiphase heterostructure sodium-ion battery metal oxide cathode material and its preparation method. The metal oxide cathode material of this invention is composed of at least two crystal phases selected from monoclinic P′3, cubic, hexagonal P2, and hexagonal P3. The preparation process includes: dissolving Ni and Mn sources in deionized water, adding a precipitant and ethylene glycol, and obtaining a precursor through a hydrothermal reaction; mixing the precursor with Co, Cu, and Na sources, and calcining to obtain the metal oxide cathode material. The multiphase heterostructure prepared by this invention is highly controllable, the operation process is simple, and it is applicable to other synthesis methods, thus facilitating industrial production. The obtained cathode material can mitigate structural distortion caused by phase transitions during charging and discharging, and improve the Na+ efficiency. + Reaction kinetics, thereby achieving excellent rate performance and cycle stability.

A synergistic stabilization effect in a Nb-doped P2-type single crystal cobalt-free layered oxide cathode material, offering remarkable cycling stability and high-power performance for Na-ion batteries have unveiled in this study. The introduction of Nb in the transition metal layer not only reduces the electronic band gap but also enhances electronic conductivity and mitigates ionic diffusion energy barriers.

This invention belongs to the field of lithium battery material technology, specifically relating to a metal oxide / mesoporous manganese dioxide / conductive polymer composite material, its preparation method, and its application. The preparation method includes the following steps: 1) ball milling a commercial metal oxide; 2) mixing the metal oxide powder with an organic polymer monomer and a methyl orange solution and ultrasonically dispersing the mixture to obtain a liquid mixture; 3) adding a potassium permanganate solution to the liquid mixture and performing a high-pressure hydrothermal reaction under stirring to obtain the composite material; 4) subjecting the composite material to alkali treatment, filtering, washing with water, and drying to obtain the metal oxide / mesoporous manganese dioxide / conductive polymer composite material. This metal oxide / mesoporous manganese dioxide / conductive polymer composite material can be used to prepare lithium battery cathode materials with high specific capacity, high conductivity, and high stability in a simple, efficient, and low-cost manner. It is easy to industrialize and solves the problems of low conductivity and poor rate discharge performance of traditional metal oxide cathode materials.

The invention relates to the technical field of sodium ion battery positive electrode materials, in particular to a boron-modified O3-phase sodium ferro-nickel manganate layered oxide positive electrode material and a preparation method and application thereof. The chemical general formula of the boron-modified O3-phase sodium ferronickel manganate layered oxide positive electrode material is NaNi1 / 3Mn1 / 3Fe1 / 3BxO2, x is greater than 0 and less than or equal to 0.2, and the boron-modified O3-phase sodium ferronickel manganate layered oxide positive electrode material is prepared by taking Na2B4O7. 10H2O as a boron source and co-sintering the boron source, Ni1 / 3Mn1 / 3Fe1 / 3 (OH) 2 precursor and Na2CO3 at high temperature, so that a composite structure of boron element doping and a NaBO2 surface coating layer is formed. Through a strategy of combining element doping and compound surface modification, a series of problems faced by the sodium ion positive electrode material are effectively solved, the electrochemical performance of the material is remarkably improved, and particularly, the performance is excellent in the aspects of cycling stability and capacity retention rate.

The present invention discloses a sodium-magnesium hybrid battery with a P2-phase layered oxide cathode material, which includes a positive electrode sheet, a negative electrode sheet and a Na / Mg double-salt electrolyte. The positive electrode sheet includes a P2-phase layered oxide cathode material, and the negative electrode sheet is pure magnesium or a magnesium alloy. The present invention also provides a preparation method and an application of the sodium-magnesium hybrid battery with the P2-phase layered oxide cathode material. The present invention fundamentally avoids the consumption of raw sodium, and the relatively high specific capacity of metallic magnesium can additionally compensate for Mg<supgt;2+< / supgt;, enabling the battery to have a relatively high energy density; dendrites will not be generated on the surface of the metallic magnesium negative electrode, improving the intrinsic safety of the battery; while giving play to the inherent advantages of magnesium batteries, it also takes into account the advantage of the high ion transfer rate of the P2-phase layered oxide cathode material, having a relatively high first-cycle charge-discharge specific capacity and cycle stability; it can be used for energy storage devices in hydropower generation, wind power generation, backup power supplies or communication base stations, as well as power batteries for electric bicycles and low-speed electric vehicles.

The embodiment of the invention relates to a high-voltage stable sodium-electrode layered oxide positive electrode material as well as a preparation method and application thereof. The positive electrode material comprises a titanium-based sodium ion layered oxide positive electrode material NaxTiaMbO2 which is formed on the surface of the material in situ through one-time sintering and has a cubic phase with the thickness smaller than 5 nm, and the weighted average ion potential phi M of other cations except sodium ions in the positive electrode material NaxTiaMbO2 is adjusted to meet the condition that phi M is larger than 50.5 nm <-1 > and smaller than or equal to 51.9 nm <-1 >, therefore, the bonding effect of transition metal and oxygen in the layered oxide positive electrode material of the sodium ion battery is adjusted, and a bulk phase structure of the positive electrode material is formed; m in the positive electrode material NaxTiaMbO2 is a transition metal element and comprises at least four elements; the at least four elements comprise Ni < 2 + >, Mn < 4 + >, and at least two of Li < + >, Cu < 2 + >, Al < 3 + > and Fe < 3 + >; and the positive electrode material NaxTiaMbO2 satisfies electric neutrality and satisfies 0.9 < = x < = 1.05, 0.05 < = a < = 0.3 and a + b = 1.

The invention belongs to the technical field of batteries, and particularly relates to a sodium-electrode layered oxide positive electrode active material and application thereof. The positive electrode active material is obtained by coating a sodium-nickel-cobalt-manganese base material with a phosphate lanthanum material. Specifically, the mass ratio of the base material to the coating material is 1: (0.0001-0.05). The composition of a base material is NaxNiaCobMncO2, x is greater than or equal to 0.8 and less than or equal to 1, a + b + c is equal to 1, and an O3 phase structure is adopted; and the coating material is composed of LaAl (PO4) 2, LaLi3 (PO4) 4 or LaFe (PO4) 2. The preparation process comprises the following steps: 1, mixing a nickel-cobalt-manganese series precursor and a sodium source material in proportion, and calcining to obtain a base material; 2, ultrasonically mixing the La < 3 + > source material, the PO4 < 3-> source material and any one of aluminum nitrate, lithium acetate and ferric sulfate in absolute ethyl alcohol to obtain a suspension; and 3, stirring and mixing a base material and the suspension, evaporating and calcining to obtain a final product. The invention solves the problem of insufficient long-cycle stability of the positive electrode material of the existing sodium-ion battery.

The invention discloses a method for preparing a sodium-ion battery high-entropy oxide positive electrode material from a red mud extract, and relates to the technical field of battery positive electrode material preparation. According to the method, the red mud is used as one of main raw material sources, aluminum, iron, titanium and magnesium elements naturally coexisting in the red mud are used as multi-metal component precursors, sodium, nickel and manganese elements are introduced as additional components, and a high-entropy oxide positive electrode material system is constructed through multi-element cooperative regulation and control. The preparation method comprises the steps of red mud pretreatment, uniform mixing with an external metal source, thermal activation treatment, sodium source introduction, mechanical ball milling, high-temperature sintering and the like, and the multi-component high-entropy oxide positive electrode material with the layered structure is prepared. In the material, various metal elements are distributed in crystal lattices in a highly disordered manner, a stable high-entropy structure is formed, phase separation and structural collapse are effectively inhibited, and the structural stability and electrochemical reaction kinetics performance of the material in the charging and discharging process are improved.

A method for preparing an air-stabilized sodium-ion battery cathode material with in-situ phosphate coating is disclosed. This method addresses the technical problems of poor moisture resistance and low cycle retention in existing layered oxide cathodes. The material of this invention involves in-situ coating of phosphate onto the surface of a layered oxide-type sodium-ion battery cathode material and gradient doping of metal ions into the material's interior. Preparation method: Layered oxide-type sodium-ion battery cathode material particles, a phosphorus source, and a metal source are mixed in NMP, followed by drying and calcination to obtain the cathode material. O3-NaNi is used as the air-stabilized coating layer with sodium calcium phosphate. 1 / 3 Fe 1 / 3 Mn 1 / 3 The initial capacity of O2 after 3 days of exposure to 50% humidity was 100.35 mAh g. ‑1 At 1C rate, the capacity retention rate after 200 cycles is 84.06%, which is 36.99% and 12.60% higher than that of the uncoated battery, respectively; it can be used in the field of sodium-ion batteries.

The invention discloses preparation and application of a layered oxide positive electrode material of a high-rate sodium-ion battery, and particularly relates to the technical field of sodium-ion batteries, the chemical formula of the layered oxide positive electrode material of the high-rate sodium-ion battery is NaxN iaCobFecMndAeO2, and x is greater than or equal to 0.9 and less than or equal to 1.05; 0 < = a < = 0.4; 0 < = b < = 0.4; 0 < = c < = 0.4; 0 < = d < = 0.4; 0 < = e < = 0.4, and a + b + c + d + e = 1. The preparation method comprises the following steps: mixing a sodium source, a nickel source, a cobalt source, an iron source, a manganese source and an A-site metal source according to a stoichiometric ratio, carrying out wet ball milling with ethanol, drying, and calcining in air at 900 DEG C for 15 hours. Through a multi-element doping strategy, the sodium ion diffusion dynamics, the electrochemical environment and the structural stability of the material are effectively improved, the rate capability, the cycle life and the air stability of the positive electrode material are remarkably improved, and the positive electrode material is suitable for the field of high-power sodium ion batteries.

The invention discloses a layered oxide positive electrode material of a sodium-ion battery and a preparation method of the layered oxide positive electrode material, and belongs to the technical field of batteries. The method comprises the following steps: preparing a NaNi < 0.33 > Mn < 0.33 > Fe < 0.33 > O2 precursor, mixing the precursor with a Na2S and P2S5 mixture under argon, carrying out heat treatment at 500 DEG C, and sintering with sodium hydroxide in an oxygen atmosphere at 800 DEG C to obtain the material. The core of the material is that a continuous super-ion conductor phase is formed on a grain boundary, a three-dimensional ion transmission network and a mechanical strengthening framework are constructed, the ion diffusion efficiency and the structural stability are remarkably improved, high-rate and long-cycle performance breakthrough is achieved, the process is controllable, and the industrialization potential is large.

The present invention discloses a two-dimensional heterojunction coated layered oxide positive electrode material and its preparation method and application, which belongs to the technical field of lithium ion battery positive electrode material modification. The preparation method of the two-dimensional heterojunction coated layered oxide positive electrode material comprises the following steps: the layered oxide is alternately coated with porous titanium iron oxide nanosheets and porous reduced graphene oxide, and sintered to obtain the two-dimensional heterojunction coated layered oxide positive electrode material; the porous titanium iron oxide nanosheet is a two-dimensional Ti with a porous structure. 0.6 Fe 0.4 O2 nanosheets; the layered oxide comprises ternary lithium, lithium cobalt oxide, or a lithium-rich manganese-based oxide. The present invention utilizes a combination of specific porous titanium iron oxide nanosheets and porous reduced graphene oxide to coat the layered oxide, achieving uniform coating of the layered oxide positive electrode surface with a two-dimensional heterojunction, thus avoiding performance variations caused by uneven localized coating.