A positive electrode material for quasi-solid-state battery and preparation method thereof

Abstract

The present invention provides a cathode material for quasi-solid-state batteries and a method for preparing the same. This invention utilizes a simple high-temperature sintering method to prepare a metal-doped, high-nickel ternary material. This material is then combined with plasma surface treatment and electrospinning technology for coating to produce a cathode material for quasi-solid-state batteries. Compared to existing technologies, the cathode material obtained in this invention exhibits controllable morphology and excellent stability, significantly improving cycle and rate performance in quasi-solid-state batteries.

Description

Technical Field

[0001] The present invention belongs to the technical field of quasi-solid-state batteries, and specifically relates to a positive electrode material for a quasi-solid-state battery and a preparation method thereof. Background Art

[0002] To meet the development needs of high-safety lithium-ion batteries, quasi-solid-state electrolyte systems have gradually become a highly promising research system in lithium-ion batteries. High-nickel lithium-ion batteries (Ni molar content ≥ 0.60) have gradually occupied a prominent position in the power battery market due to their advantages such as higher energy density at low cut-off voltage and low cost due to low Co content. The application of high-nickel ternary materials (nickel-cobalt-manganese ternary materials with Ni molar content ≥ 0.60) in quasi-solid-state batteries is an inevitable trend in the development of longer-lasting, more stable and safer power batteries.

[0003] As the nickel content in the positive electrode material increases, the discharge capacity of the positive electrode increases accordingly, but this also brings a series of problems to the battery. During the cycle, factors such as the formation of microcracks due to changes in the positive electrode volume can have adverse effects on the battery. For example, the mixing of lithium and nickel in the positive electrode structure is aggravated, lithium precipitates on the surface of the positive electrode material to form residual alkali, and high-valent metal elements have strong oxidizing ability, which easily causes side reactions with the electrode surface film and the liquid phase components in the quasi-solid electrolyte. These factors lead to poor cycle performance and rate performance of the battery, large self-discharge, and affect the battery's use.

[0004] To address the above-mentioned issues, currently studied effective improvement methods include element doping and surface coating modification of high-nickel ternary materials. However, even after these improvements, problems still exist, such as unstable structure of high-nickel ternary materials, poor battery cycle performance, and poor rate performance. Summary of the Invention

[0005] To address the deficiencies of the prior art, the present invention provides a quasi-solid-state battery cathode material and a method for preparing the same. The cathode material exhibits excellent structural stability, high cycle performance, and high rate capability, remedying the structural instability, low initial charge and discharge efficiency, poor cycle performance, and poor rate capability of high-nickel ternary materials.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A positive electrode material comprises a metal-doped high-nickel ternary material, octadecylphosphonic acid and carbon fiber containing polar nitrogen; the octadecylphosphonic acid is coated on the surface of the metal-doped high-nickel ternary material; and the metal-doped high-nickel ternary material coated with octadecylphosphonic acid is attached to the surface of the carbon fiber containing polar nitrogen.

[0008] As a preferred embodiment of the present invention, the octadecylphosphonic acid is coated on part or all of the surface of the metal-doped high-nickel ternary material.

[0009] As a preferred embodiment of the present invention, the octadecylphosphonic acid and the metal-doped high-nickel ternary material are connected by a covalent bond. Preferably, the octadecylphosphonic acid and the hydroxyl groups on the surface of the metal-doped high-nickel ternary material are connected by a covalent bond.

[0010] As a preferred embodiment of the present invention, the chemical formula of the metal-doped high nickel ternary material is LiNi x Co y Mn 1-x-y-z1-z2 M 1 z1 M 2 z2 O2, 0.8≤x<1, 0 <y≤0.12,0<z1+z2≤0.08,M 1 is at least one of rubidium, strontium, zirconium, niobium, molybdenum, and technetium, M 2 At least one of the rare earth elements.

[0011] As a preferred embodiment of the present invention, the rare earth element is selected from at least one of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), yttrium (Y) and scandium (Sc).

[0012] As a preferred embodiment of the present invention, the metal-doped high-nickel ternary material is a high-nickel ternary material doped with bimetallic atoms. The doping of bimetallic atoms can stabilize the crystal structure of the high-nickel ternary material and reduce lithium-nickel mixing.

[0013] As a preferred embodiment of the present invention, the metal-doped high-nickel ternary material is a metal-doped high-nickel ternary material that has been plasma-treated, and the plasma treatment conditions are: the power is 500-800W, the atmosphere introduced is an oxygen-containing gas (such as air or oxygen), the cavity vacuum is 20-50Pa, and the plasma treatment (glow discharge) time is 400-600s.

[0014] As a preferred embodiment of the present invention, the median particle size Dv50 of the metal-doped high-nickel ternary material is 1μm to 10μm, preferably 2μm to 5μm, for example, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm.

[0015] As a preferred embodiment of the present invention, the metal-doped high-nickel ternary material has a very small possibility of lithium-nickel rearrangement, which ensures the stability of the positive electrode material. A covalent bond is formed between the hydroxyl group and octadecylphosphonic acid on the surface of the metal-doped high-nickel ternary material, thereby realizing the covalent connection of the octadecylphosphonic acid and the metal-doped high-nickel ternary material. Specifically, the surface of the metal-doped high-nickel ternary material is connected with more hydroxyl groups by plasma surface treatment, and the droplets containing octadecylphosphonic acid are sprayed and impacted on the surface of the metal-doped high-nickel ternary material by means of electrostatic spinning. It will trigger the formation of a covalent bond between the surface phosphonic acid group and the hydroxyl group, which is convenient for the attachment of octadecylphosphonic acid. On this basis, the metal-doped high-nickel ternary material coated with octadecylphosphonic acid is attached to the surface of the carbon fiber containing polar nitrogen, which is beneficial to improving the conductivity and hydrophobicity of the positive electrode material, and further realizing the good structural stability, high cycle performance and high rate performance of the positive electrode material.

[0016] As a preferred embodiment of the present invention, the thickness of the coating layer formed by the octadecylphosphonic acid is 5 nm to 25 nm, for example, 5 nm, 10 nm, 15 nm, 20 nm or 25 nm.

[0017] As a preferred embodiment of the present invention, octadecylphosphonic acid, a carbon-nitrogen precursor, and polyacrylonitrile (PAN) are dissolved in a solvent to form a spinning solution, and the spinning solution is sprayed on the surface of the metal-doped high-nickel ternary material using electrospinning technology, dried, and sintered at a high temperature to prepare the positive electrode material; the conditions for the electrospinning are: the spinning voltage is 15 to 20 kV, the humidity is less than 10%, and the needle model is 20 to 22G.

[0018] As a preferred embodiment of the present invention, the positive electrode material is in a fibrous shape.

[0019] In the present invention, Dv50 is measured by laser particle size analysis, which means that 50% of the particles are within the measured size value. Specifically, Dv50 is the particle size at which the cumulative distribution of particles reaches 50%, that is, the volume content of particles smaller than this particle size accounts for 50% of all particles. Also called the median diameter or median particle size, this is a typical value representing the particle size, which accurately divides the population into two equal parts, that is, 50% of the particles have a particle size exceeding this value, and 50% of the particles have a particle size below this value. If the Dv50 of a sample is 5μm, it means that among all the particles of the sample, particles larger than 5μm account for 50% and particles smaller than 5μm also account for 50%.

[0020] As a preferred embodiment of the present invention, the mass of the octadecylphosphonic acid accounts for 0.5% to 2.0% of the total mass of the metal-doped high nickel ternary material, for example, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2.0%.

[0021] As a preferred embodiment of the present invention, the mass of the carbon fiber containing polar nitrogen accounts for 0.1% to 1.0% of the total mass of the metal-doped high-nickel ternary material, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1.0%.

[0022] As a preferred embodiment of the present invention, the diameter of the carbon fiber containing polar nitrogen is 10 to 30 μm (such as 10 μm, 12 μm, 15 μm, 16 μm, 18 μm, 20 μm, 22 μm, 24 μm, 25 μm, 26 μm, 28 μm or 30 μm), and the length of the carbon fiber containing polar nitrogen is greater than 10 μm.

[0023] As a preferred embodiment of the present invention, the carbon fiber containing polar nitrogen is prepared by high-temperature sintering a carbon-nitrogen precursor with polyacrylonitrile, wherein the carbon-nitrogen precursor is one or more of melamine, cyanuric acid, and urea. The high-temperature sintering conditions are: heating to 450-550°C at a heating rate of 2-5°C / min in an inert atmosphere, holding for 4-6 hours, and then cooling to room temperature.

[0024] As a preferred embodiment of the present invention, the mass of the carbon-nitrogen precursor is 30-50% of the mass of polyacrylonitrile.

[0025] As a preferred embodiment of the present invention, the polar nitrogen is pyrrolic nitrogen and / or pyridinic nitrogen.

[0026] As a preferred embodiment of the present invention, the polar nitrogen content is 1% to 30%, for example, 1%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 23%, 25%, 26%, 28% or 30%. The polar nitrogen content refers to the percentage of the mass of the polar nitrogen to the total mass of the carbon fiber containing polar nitrogen.

[0027] As a preferred embodiment of the present invention, the positive electrode material is used in a quasi-solid-state battery, preferably a quasi-solid-state lithium-ion battery.

[0028] The present invention also provides a method for preparing the above-mentioned positive electrode material, the preparation method comprising the following steps:

[0029] (1) The doping metal M1 Soluble salt, doping metal M 2 The soluble salt and the high nickel ternary material precursor are dissolved in ethanol and heated to prepare a metal-doped high nickel ternary material precursor;

[0030] (2) ball-milling the metal-doped high-nickel ternary material precursor obtained in step (1) and the lithium source, and then sintering the mixture to obtain the metal-doped high-nickel ternary material;

[0031] (3) The metal-doped high-nickel ternary material obtained in step (2) is treated with plasma, octadecylphosphonic acid, a carbon-nitrogen precursor, and polyacrylonitrile are dissolved in a solvent to form a spinning solution, the spinning solution is sprayed on the surface of the metal-doped high-nickel ternary material using electrospinning technology, and sintered at a high temperature to prepare the positive electrode material.

[0032] As a preferred embodiment of the present invention, the doping metal M in step (1) 1 is at least one of rubidium, strontium, zirconium, niobium, molybdenum, and technetium; the doping metal M in step (1) 2 At least one of the rare earth elements.

[0033] As a preferred embodiment of the present invention, the doping metal M in step (1) 1 The soluble salt is metal M 1 One or more of acetate, chloride, nitrate, etc.; the doping metal M in step (1) 2 The soluble salt is metal M 2 One or more of acetate, chloride, nitrate, etc.

[0034] As a preferred embodiment of the present invention, the doping metal M in step (1) 1 Soluble salts and doping metals M 2 The total mass of the soluble salt is 0.5-3.0% of the mass of the high-nickel ternary material precursor.

[0035] As a preferred embodiment of the present invention, the step (1) specifically comprises: adding the doping metal M 1 Soluble salt, doping metal M 2 The soluble salt and the high nickel ternary material precursor are dissolved in ethanol according to a stoichiometric ratio, heated and fully stirred, evaporated to dryness, and then placed in a blast oven for drying to obtain a metal-doped high nickel ternary material precursor.

[0036] As a preferred embodiment of the present invention, the lithium source in step (2) is one or more of lithium hydroxide, lithium nitrate, lithium carbonate, lithium oxalate, and lithium acetate.

[0037] As a preferred embodiment of the present invention, the molar ratio of the metal-doped high-nickel ternary material precursor and the lithium source in step (2) is (1.05-1.13):1, for example, 1.05:1, 1.06:1, 1.08:1, 1.1:1 or 1.13:1.

[0038] As a preferred embodiment of the present invention, the ball milling in step (2) is performed in a planetary ball mill, the ball milling speed is 400-600 rpm, and the ball milling time is 4-8 hours.

[0039] As a preferred embodiment of the present invention, the sintering conditions in step (2) are to heat the temperature to 450-550°C at a heating rate of 2-5°C / min, keep the temperature for 5-8 hours, and then heat the temperature to 700-850°C at a heating rate of 2-5°C / min, and keep the temperature for 12-15 hours.

[0040] As a preferred embodiment of the present invention, the plasma treatment conditions in step (3) are 500-800W, the atmosphere introduced is an oxygen-containing gas (such as air or oxygen), the vacuum degree of the plasma treatment chamber is 20-50Pa, and the plasma treatment (glow discharge) time is 400-600s. The purpose of the plasma treatment is to connect hydroxyl groups on the surface of the metal-doped high-nickel ternary material to facilitate subsequent coating treatment.

[0041] As a preferred embodiment of the present invention, the step (3) specifically includes: dissolving octadecylphosphonic acid, polyacrylonitrile and carbon nitrogen precursor in DMF to form a spinning solution, transferring it to a needle tube, spreading the metal-doped high-nickel ternary material after plasma treatment obtained in step (2) on aluminum foil, using electrospinning technology to spray the spinning solution on the surface of the metal-doped high-nickel ternary material, drying, and high-temperature sintering to prepare the positive electrode material.

[0042] As a preferred embodiment of the present invention, the electrospinning voltage in step (3) is 15-20 kV, the humidity is lower than 10%, and the needle size is 20-22G.

[0043] As a preferred embodiment of the present invention, the solvent in step (3) is DMF, and the mass of octadecylphosphonic acid is 0.5% to 2.0% of the total mass of the metal-doped high-nickel ternary material.

[0044] As a preferred embodiment of the present invention, the molecular weight of the polyacrylonitrile in step (3) is 50,000 to 200,000, and the amount of polyacrylonitrile added is 10 to 20% of the total mass of the solvent.

[0045] As a preferred embodiment of the present invention, the amount of the carbon-nitrogen precursor added in step (3) is 30-50% of the total mass of polyacrylonitrile, preferably 30%, 35%, 40%, 45% or 50%.

[0046] As a preferred embodiment of the present invention, the drying conditions in step (3) are forced air drying at 50-70° C., and the drying time is 10-18 hours.

[0047] As a preferred embodiment of the present invention, the high temperature sintering conditions in step (3) are to increase the temperature to 450-550°C at a heating rate of 2-5°C / min, keep the temperature for 4-6 hours, and then cool to room temperature.

[0048] The present invention also provides a positive electrode material prepared by the above preparation method.

[0049] The present invention also provides a positive electrode sheet, which comprises the positive electrode material mentioned above.

[0050] As a preferred embodiment of the present invention, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer coated on at least one surface of the positive electrode current collector, and the positive electrode active material layer includes a positive electrode material.

[0051] As a preferred embodiment of the present invention, the positive electrode current collector is selected from one or more of aluminum foil, carbon-coated aluminum foil, and perforated aluminum foil.

[0052] The present invention also provides a battery, which includes the above-mentioned positive electrode material, or the battery includes the above-mentioned positive electrode sheet.

[0053] As a preferred embodiment of the present invention, the battery is a quasi-solid-state battery.

[0054] Beneficial effects of the present invention:

[0055] The present invention provides a positive electrode material for a quasi-solid-state battery and a preparation method thereof. The positive electrode material comprises a metal-doped high-nickel ternary material, octadecylphosphonic acid, and carbon fiber containing polar nitrogen; the octadecylphosphonic acid is coated on the surface of the metal-doped high-nickel ternary material; and the metal-doped high-nickel ternary material coated with octadecylphosphonic acid is attached to the surface of the carbon fiber containing polar nitrogen. The present invention first dopes the high-nickel ternary material with metal elements (at least one of rubidium, strontium, zirconium, niobium, molybdenum, and technetium, and at least one of rare earth elements). Since the atomic radius of rare earth elements is larger than that of the ternary material, they can easily fill its grains and defects. Rare earth elements easily combine with nickel to form compounds with high melting points. Therefore, the stability of the ternary material can be improved after modification. Some metal elements in the fifth period have an unfilled 4f electron layer structure, which produces a variety of electronic energy levels, can form bonds with lithium, and reduce lithium-nickel mixing. The two introduced metal cations change the crystal structure of the high nickel ternary material after entering the high nickel ternary material, causing the valence state of some nickel, cobalt and manganese in the bulk phase of the high nickel ternary material to change, and the orbital generates holes, thereby improving the electronic conductivity; at the same time, it can also reduce the mixing of lithium and nickel and stabilize the positive electrode structure; secondly, after plasma treatment under an oxygen-containing atmosphere, hydroxyl groups are formed on the surface of the high nickel ternary material, and when droplets containing octadecylphosphonic acid are sprayed and impacted on the surface of the high nickel ternary material, surface covalent bonds are formed, and a coating layer structure can be formed on the surface of the metal-doped high nickel ternary material without thermal curing. The coating layer structure has good thermodynamic stability, can stabilize the structure of the positive electrode material during the charge and discharge process, and improve high temperature performance; finally, the polyacrylonitrile (PAN) and carbon nitrogen precursor introduced during spinning can improve the overall conductivity and hydrophobicity after sintering. Compared with the prior art, the positive electrode material obtained by the present invention has controllable morphology and good stability, and can be used in quasi-solid-state batteries to significantly improve cycle performance and rate performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 These are electron microscope images of the positive electrode materials of Example 1 and Comparative Example 1, wherein a is the SEM image of the positive electrode material of Comparative Example 1; b and c are the SEM images of the positive electrode material of Example 1; and d is the TEM image of the positive electrode material of Example 1.

[0057] Figure 2 These are rate performance graphs of the batteries of Example 1 and Comparative Example 1 at current densities of 2.0C, 3.0C, 4.0C, 5.0C, 10.0C, and 2.0C, respectively, where B is the battery of Comparative Example 1 and D is the battery of Example 1.

[0058] Figure 3 Graphs showing the cycling performance of the batteries of Example 1 and Comparative Example 1 at a current density of 0.5 C, wherein B is the battery of Comparative Example 1 and D is the battery of Example 1.

[0059] Figure 4 This is a flow chart of the preparation process of the positive electrode material according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0060] The present invention will be described in further detail below with reference to specific examples. It should be understood that the following examples are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0061] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the reagents, materials, etc. used in the following examples are all commercially available unless otherwise specified.

[0062] Example 1

[0063] Step 1: Weigh 0.0124g of strontium nitrate and 0.0124g of cerium nitrate and dissolve them in 5mL of ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0064] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.05:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0065] Step 3: Thinly spread the high-nickel ternary material obtained in step 2 on aluminum foil and place it in the plasma surface treatment chamber. Set the power to 500W, connect the air inlet to air, and plasma treatment (glow discharge) time to 600s. After starting the instrument, adjust the flow rate valve before glow discharge to maintain the pressure in the plasma surface treatment chamber at 50Pa.

[0066] Weigh 2% of the mass of the doped high-nickel ternary material into octadecylphosphonic acid and dissolve it in 5mL of DMF. Then add 10% of PAN with a molecular weight of 50,000, which accounts for 10% of the mass of DMF, and add 30% of melamine powder, which accounts for 30% of the mass of PAN, to form a uniform spinning solution. Transfer it to a 20G single-axis needle syringe, set the humidity to 5% and the voltage to 15kV, and use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material modified by a plasma surface treatment instrument. Put it in a 70°C blast oven, dry it for 18 hours, take it out, put it in an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 550°C at a heating rate of 2°C / min, keep it warm for 5 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0067] Example 2

[0068] Step 1: Weigh 0.0124g technetium chloride and 0.0124g ytterbium chloride and dissolve them in 5mL ethanol. Add 1g Ni 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0069] Step 2: Weigh lithium hydroxide according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.08:1, and add it and the doped high-nickel ternary material precursor into a planetary ball mill at a speed of 400 rpm and ball mill for 4 hours to fully mix. Collect the ball-milled powder and put it into an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter at room temperature. First, heat it to 550°C at a heating rate of 5°C / min, keep it warm for 8 hours, then heat it to 850°C at the same heating rate, and keep it warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0070] Step 3: Thinly spread the high-nickel ternary material obtained in step 2 on aluminum foil and place it in the plasma surface treatment chamber. Set the power to 500W, connect the air inlet to air, and plasma treatment (glow discharge) time to 600s. After starting the instrument, adjust the flow rate valve before glow discharge to maintain the pressure in the plasma surface treatment chamber at 50Pa.

[0071] Weigh 2% of the mass of the doped high-nickel ternary material into octadecylphosphonic acid and dissolve it in 5mL of DMF. Then add 10% of the mass of PAN with a molecular weight of 70,000, which accounts for 10% of the mass of DMF, and add 40% of the mass of PAN to form a uniform spinning solution. Transfer it to a 20G single-axis needle syringe, set the humidity to 5%, and the voltage to 15kV. Use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material modified by a plasma surface treatment instrument, put it into a 70°C blast oven, dry it for 18 hours, take it out, put it into an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 550°C at a heating rate of 2°C / min, keep it warm for 5 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0072] Example 3

[0073] Step 1: Weigh 0.01g strontium nitrate and 0.01g praseodymium nitrate and dissolve them in 5mL ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0074] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.07:1, and is added to a planetary ball mill with a rotation speed of 500 rpm for 6 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0075] Step 3: Spread the doped high-nickel ternary material obtained in step 2 thinly on aluminum foil and place it in the plasma surface treatment chamber. Set the power to 500W, connect the air inlet to air, and plasma treatment (glow discharge) time to 400s. After starting the instrument, adjust the flow rate valve before glow discharge to maintain the plasma surface treatment chamber pressure at 50Pa.

[0076] Weigh 2% of the mass of the doped high-nickel ternary material into octadecylphosphonic acid and dissolve it in 5mL of DMF. Then add 10% of the mass of DMF with a molecular weight of 150,000 PAN, and add 50% of the mass of PAN to form a uniform spinning solution. Transfer it to a 20G uniaxial needle syringe, set the humidity to 5% and the voltage to 20kV, and use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material modified by a plasma surface treatment instrument. Put it in a 70°C blast oven, dry it for 16 hours, take it out, put it into an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 550°C at a heating rate of 2°C / min, keep it warm for 5 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0077] Example 4

[0078] Step 1: Weigh 0.01g niobium acetate and 0.01g dysprosium nitrate and dissolve them in 5mL ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0079] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.07:1, and is added to a planetary ball mill with a rotation speed of 500 rpm for 6 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 450°C at a heating rate of 2°C / min, kept warm for 8 hours, and then increased to 750°C at the same heating rate, and kept warm for 12 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0080] Step 3: Spread the doped high-nickel ternary material obtained in step 2 thinly on aluminum foil and place it in the plasma surface treatment chamber. Set the power to 500W, connect the air inlet to air, and plasma treatment (glow discharge) time to 400s. After starting the instrument, adjust the flow rate valve before glow discharge to maintain the plasma surface treatment chamber pressure at 30Pa.

[0081] Weigh 2% of the mass of the doped high-nickel ternary material into octadecylphosphonic acid and dissolve it in 10mL of DMF. Then add 10% of PAN with a molecular weight of 150,000, which accounts for 10% of the mass of DMF, and add 50% of urea powder, which accounts for PAN mass, to form a uniform spinning solution. Transfer it to a 20G uniaxial needle syringe, set the humidity to 7% and the voltage to 20kV, and use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material modified by a plasma surface treatment instrument. Put it in a 60°C blast oven, dry it for 18 hours, take it out, put it into an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 450°C at a heating rate of 4°C / min, keep it warm for 6 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0082] Example 5

[0083] Step 1: Weigh 0.015g of promethium acetate and 0.015g of niobium nitrate and dissolve them in 5mL of ethanol. 0.8 Co 0.12 Mn 0.08 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0084] Step 2: Weigh lithium carbonate according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.10:1, and add it and the doped high-nickel ternary material precursor into a planetary ball mill at a speed of 600 rpm for 4 hours to fully mix. Collect the ball-milled powder and put it into an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter at room temperature. First, heat it to 450°C at a heating rate of 2°C / min, keep it warm for 8 hours, then heat it to 750°C at the same heating rate, keep it warm for 12 hours, and naturally cool it to room temperature to obtain the doped high-nickel ternary material.

[0085] Step 3: Spread the doped high-nickel ternary material obtained in step 2 thinly on aluminum foil and place it in the plasma surface treatment chamber. Set the power to 800W, connect the air inlet to air, and plasma treatment (glow discharge) time to 400s. After starting the instrument, adjust the flow rate valve before glow discharge to maintain the plasma surface treatment chamber pressure at 40Pa.

[0086] Weigh 0.6% of octadecylphosphonic acid, which accounts for 0.6% of the mass of the doped high-nickel ternary material, and dissolve it in 10mL DMF. Then add 2% of PAN with a molecular weight of 80,000, which accounts for 2% of the mass of DMF, and add 45% of a mixed powder of cyanuric acid and melamine, which accounts for 45% of the mass of PAN, to form a uniform spinning solution. Transfer it to a 22G uniaxial needle syringe, set the humidity to 3% and the voltage to 20kV, and use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material modified by a plasma surface treatment instrument. Put it in a 70°C blast oven, dry it for 10 hours, take it out, put it into an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 500°C at a heating rate of 3°C / min, keep it warm for 6 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0087] Example 6

[0088] Step 1: Weigh 0.0124g of strontium nitrate and 0.0124g of terbium nitrate and dissolve them in 5mL of ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0089] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.05:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0090] Step 3: Thinly spread the high-nickel ternary material obtained in step 2 on aluminum foil and place it in the plasma surface treatment chamber. Set the power to 500W, connect the air inlet to air, and plasma treatment (glow discharge) time to 600s. After starting the instrument, adjust the flow rate valve before glow discharge to maintain the pressure in the plasma surface treatment chamber at 50Pa.

[0091] Weigh 0.8% of octadecylphosphonic acid, which accounts for 0.8% of the mass of the doped high-nickel ternary material, and dissolve it in 10mL DMF. Then add PAN with a molecular weight of 150,000, which accounts for 12% of the mass of DMF, and add a mixed powder of melamine and urea, which accounts for 35% of the mass of PAN, to form a uniform spinning solution. Transfer it to a 22G uniaxial needle syringe, set the humidity to 9% and the voltage to 15kV, and use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material modified by a plasma surface treatment instrument. Put it in a 70°C blast oven, dry it for 10 hours, take it out, put it into an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 550°C at a heating rate of 5°C / min, keep it warm for 4 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0092] Example 7

[0093] Step 1: Weigh 0.0124g of molybdenum nitrate and 0.0124g of cerium nitrate and dissolve them in 5mL of ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0094] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.13:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0095] Step 3: Thinly spread the high-nickel ternary material obtained in step 2 on aluminum foil and place it in the plasma surface treatment chamber. Set the power to 500W, connect the air inlet to air, and plasma treatment (glow discharge) time to 600s. After starting the instrument, adjust the flow rate valve before glow discharge to maintain the pressure in the plasma surface treatment chamber at 50Pa.

[0096] Weigh 1.5% of octadecylphosphonic acid, which accounts for 1.5% of the mass of the doped high-nickel ternary material, and dissolve it in 10mL of DMF. Then add PAN with a molecular weight of 50,000, which accounts for 12% of the mass of DMF, and add a mixed powder of melamine and urea, which accounts for 35% of the mass of PAN, to form a uniform spinning solution. Transfer it to a 22G single-axis needle syringe, set the humidity to 5% and the voltage to 15kV, and use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material modified by a plasma surface treatment instrument. Put it in a 70°C blast oven, dry it for 10 hours, take it out, put it into an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 550°C at a heating rate of 5°C / min, keep it warm for 4 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0097] Comparative Example 1

[0098] Step 1: Weigh 1g Ni 0.8 Co 0.09 Mn 0.11 The O2 precursor was dissolved in 5 mL of ethanol, magnetically stirred at 60 °C and the solvent evaporated to obtain a high-nickel ternary material precursor;

[0099] Step 2. Lithium hydroxide is weighed according to the molar ratio of high-nickel ternary material precursor to lithium source of 1.05:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, kept warm for 15 hours, and naturally cooled to room temperature to obtain the high-nickel ternary material.

[0100] Comparative Example 2

[0101] Step 1: Weigh 0.0248g of strontium nitrate and dissolve it in 5mL of ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0102] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.05:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0103] Comparative Example 3

[0104] Step 1: Weigh 0.0248g of cerium nitrate and dissolve it in 5mL of ethanol. Add 1g of Ni 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0105] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.05:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0106] Comparative Example 4

[0107] Step 1: Weigh 0.0124g of strontium nitrate and 0.0124g of cerium nitrate and dissolve them in 5mL of ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0108] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.05:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0109] Comparative Example 5

[0110] Step 1: Weigh 0.0124g of strontium nitrate and 0.0124g of cerium nitrate and dissolve them in 5mL of ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0111] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.05:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0112] Step 3. Weigh 2% of the mass of the doped high-nickel ternary material into octadecylphosphonic acid and dissolve it in 5mL of DMF. Add 10% of the mass of DMF and PAN with a molecular weight of 50,000, and add 30% of the mass of PAN to form a uniform spinning solution. Transfer it to a 20G uniaxial needle syringe, set the humidity to 5%, and the voltage to 15kV. Use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material, place it in a 70°C blast oven, dry it for 18 hours, take it out, place it in an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 550°C at a heating rate of 2°C / min, keep it warm for 5 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0113] Comparative Example 6

[0114] Step 1: Weigh 0.0124g of strontium nitrate and 0.0124g of cerium nitrate and dissolve them in 5mL of ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0115] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.05:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0116] Step 3: Thinly spread the high-nickel ternary material obtained in step 2 on aluminum foil and place it in the plasma surface treatment chamber. Set the power to 500W, connect the air inlet to air, and plasma treatment (glow discharge) time to 600s. After starting the instrument, adjust the flow rate valve before glow discharge to maintain the pressure in the plasma surface treatment chamber at 50Pa.

[0117] Weigh 2% of the mass of the doped high-nickel ternary material into octadecylphosphonic acid and dissolve it in 5mL of DMF. Then add 10% of the mass of DMF and a molecular weight of 50,000 PAN to form a uniform spinning solution. Transfer it to a 20G uniaxial needle syringe, set the humidity to 5% and the voltage to 15kV, and use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material modified by a plasma surface treatment instrument. Put it in a 70°C blast oven, dry it for 18 hours, take it out, put it into an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 550°C at a heating rate of 2°C / min, keep it warm for 5 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0118] Comparative Example 7

[0119] Step 1: Weigh 0.0124g of strontium nitrate and 0.0124g of cerium nitrate and dissolve them in 5mL of ethanol. 0.8 Co 0.09 Mn 0.11 O2 precursor, magnetically stirred at 60 ° C and evaporated the solvent to obtain a doped high nickel ternary material precursor;

[0120] Step 2. Lithium hydroxide is weighed according to the molar ratio of the doped high-nickel ternary material precursor and the lithium source of 1.05:1, and is added to a planetary ball mill with a rotation speed of 400 rpm for 4 hours to be fully mixed. The ball-milled powder is collected and placed in an alumina crucible with a lid, placed in a muffle furnace, and sintered at room temperature. The temperature is first increased to 550°C at a heating rate of 5°C / min, kept warm for 8 hours, and then increased to 850°C at the same heating rate, and kept warm for 15 hours. After naturally cooling to room temperature, the doped high-nickel ternary material is obtained.

[0121] Step 3: Thinly spread the high-nickel ternary material obtained in step 2 on aluminum foil and place it in the plasma surface treatment chamber. Set the power to 500W, connect the air inlet to air, and plasma treatment (glow discharge) time to 600s. After starting the instrument, adjust the flow rate valve before glow discharge to maintain the pressure in the plasma surface treatment chamber at 50Pa.

[0122] Weigh 5mL of DMF, add PAN with a molecular weight of 50,000 that accounts for 10% of the mass of DMF, add melamine powder that accounts for 30% of the mass of PAN to form a uniform spinning solution, transfer it to a 20G single-axis needle syringe, set the humidity to 5%, and the voltage to 15kV. Use an electrospinning machine to evenly spin the spinning solution on the doped high-nickel ternary material modified by a plasma surface treatment instrument, put it in a 70°C blast oven, dry it for 18 hours, take it out, put it in an alumina crucible with a lid, place it in a muffle furnace, and heat and sinter it at room temperature. First, heat it to 550°C at a heating rate of 2°C / min, keep it warm for 5 hours, and then cool it naturally to room temperature to obtain the positive electrode material.

[0123] Table 1 shows the electrochemical performance data of quasi-solid-state lithium-ion batteries using the positive electrode materials of the embodiments or comparative examples of the present invention. Table 1 shows that the positive electrode materials of the present invention significantly improve the capacity and coulombic efficiency of quasi-solid-state lithium-ion batteries.

[0124] The battery's initial charge capacity, initial discharge capacity, and coulombic efficiency were measured using the following test procedure: charge at 2.0C to 4.3V, let stand for 2 minutes, and discharge at 0.5C to 2.75V to complete the first cycle. The initial discharge capacity of the positive electrode material was calculated by dividing the initial charge capacity by the mass of the positive electrode active material. The initial discharge capacity of the positive electrode active material was calculated by dividing the initial discharge capacity by the mass of the positive electrode active material. The initial discharge capacity was calculated by dividing the initial discharge capacity by the mass of the positive electrode active material. The coulombic efficiency of the positive electrode active material is calculated as the ratio of initial discharge capacity to initial charge capacity.

[0125] Table 1 Electrochemical performance data of batteries using the positive electrode materials of the embodiments and comparative examples as positive electrodes

[0126]

[0127] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A positive electrode material, characterized in that The positive electrode material includes a metal-doped high-nickel ternary material, octadecylphosphonic acid, and carbon fiber containing polar nitrogen; the octadecylphosphonic acid is coated on the surface of the metal-doped high-nickel ternary material; the metal-doped high-nickel ternary material coated with octadecylphosphonic acid is attached to the surface of the carbon fiber containing polar nitrogen; the polar nitrogen is pyrrolic nitrogen and / or pyridinic nitrogen; The chemical formula of the metal-doped high nickel ternary material is LiNi x Co y Mn 1-x-y-z1-z2 M 1 z1 M 2 z2 O2, 0.8≤ x <1,0< y ≤0.12,0< z1+z2 ≤0.08, M 1 is at least one of rubidium, strontium, zirconium, niobium, molybdenum, and technetium, M 2 At least one of the rare earth elements.

2. The positive electrode material according to claim 1, characterized in that The octadecylphosphonic acid and the hydroxyl groups on the surface of the metal-doped high-nickel ternary material are connected through a covalent bond.

3. The positive electrode material according to claim 1, characterized in that The median particle size Dv50 of the metal-doped high-nickel ternary material is 1 μm to 10 μm.

4. The positive electrode material according to claim 1, characterized in that The thickness of the coating layer formed by the octadecylphosphonic acid is 5 nm to 25 nm; And / or, the mass of the octadecylphosphonic acid accounts for 0.5% to 2.0% of the total mass of the metal-doped high-nickel ternary material.

5. The positive electrode material according to any one of claims 1 to 4, characterized in that The mass of the carbon fiber containing polar nitrogen accounts for 0.1% to 1.0% of the total mass of the metal-doped high-nickel ternary material; And / or, the diameter of the carbon fiber containing polar nitrogen is 10-30 μm, and the length of the carbon fiber containing polar nitrogen is greater than 10 μm; And / or, the content of polar nitrogen is 1% to 30%.

6. A method for preparing the positive electrode material according to any one of claims 1 to 5, comprising the following steps: (1) Add the doped metal M 1 Soluble salt, doping metal M 2 The soluble salt and the high nickel ternary material precursor are dissolved in ethanol and heated to prepare a metal-doped high nickel ternary material precursor; (2) ball-milling the metal-doped high-nickel ternary material precursor obtained in step (1) and the lithium source, and then sintering the mixture to obtain the metal-doped high-nickel ternary material; (3) using plasma treatment of the metal-doped high-nickel ternary material obtained in step (2), dissolving octadecylphosphonic acid, a carbon-nitrogen precursor, and polyacrylonitrile in a solvent to prepare a spinning solution, spraying the spinning solution onto the surface of the metal-doped high-nickel ternary material using electrospinning technology, and sintering at a high temperature to prepare the positive electrode material; Among them, M 1 is at least one of rubidium, strontium, zirconium, niobium, molybdenum, and technetium, M 2 It is at least one of the rare earth elements; the carbon-nitrogen precursor is one or more of melamine, cyanuric acid, and urea.

7. The preparation method according to claim 6, characterized in that The doping metal M in step (1) 1 Soluble salts and doping metals M 2 The total mass of the soluble salt is 0.5~3.0% of the mass of the high-nickel ternary material precursor.

8. The preparation method according to claim 6, characterized in that The lithium source in step (2) is one or more of lithium hydroxide, lithium nitrate, lithium carbonate, lithium oxalate, and lithium acetate.

9. The preparation method according to claim 6, characterized in that The molar ratio of the metal-doped high nickel ternary material precursor and the lithium source in step (2) is (1.05~1.13):

1.

10. The preparation method according to claim 6, wherein The sintering conditions in step (2) are to increase the temperature to 450-550°C at a heating rate of 2-5°C / min, keep the temperature for 5-8 h, and then increase the temperature to 700-850°C at a heating rate of 2-5°C / min, and keep the temperature for 12-15 h.

11. The preparation method according to claim 6, wherein The plasma treatment conditions in step (3) are 500~800 W, the atmosphere introduced is an oxygen-containing gas, the vacuum degree of the plasma treatment chamber is 20~50 Pa, and the plasma treatment time is 400~600 s.

12. The preparation method according to claim 6, characterized in that Step (3) specifically includes: dissolving octadecylphosphonic acid, polyacrylonitrile and carbon nitrogen precursor in DMF to prepare a spinning solution, transferring the solution to a needle tube, spreading the metal-doped high-nickel ternary material after plasma treatment obtained in step (2) on aluminum foil, spraying the spinning solution on the surface of the metal-doped high-nickel ternary material using electrospinning technology, drying, and sintering at high temperature to prepare the positive electrode material.

13. The preparation method according to claim 6, wherein The spinning voltage of the electrospinning in step (3) is 15-20 kV, the humidity is less than 10%, and the needle size is 20-22 G.

14. The preparation method according to claim 6, characterized in that The solvent in step (3) is DMF, and the mass of octadecylphosphonic acid is 0.5% to 2.0% of the total mass of the metal-doped high-nickel ternary material.

15. The preparation method according to claim 6, characterized in that The molecular weight of polyacrylonitrile in step (3) is 50,000-200,000, and the amount of polyacrylonitrile added is 10-20% of the total mass of the solvent.

16. The preparation method according to claim 6, characterized in that The amount of carbon-nitrogen precursor added in step (3) is 30-50% of the total mass of polyacrylonitrile.

17. The preparation method according to claim 6, wherein The high-temperature sintering conditions in step (3) are to increase the temperature to 450-550°C at a heating rate of 2-5°C / min, keep the temperature for 4-6 hours, and then cool it to room temperature.

18. A positive electrode sheet, characterized in that: The positive electrode sheet comprises the positive electrode material according to any one of claims 1 to 5.

19. A battery, characterized in that: The battery comprises the positive electrode material according to any one of claims 1 to 5, or the battery comprises the positive electrode sheet according to claim 18.

20. The battery according to claim 19, characterized in that The battery is a quasi-solid-state battery.

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