Nanosheet-nanowire synergistically doped positive electrode material, preparation method and battery

Abstract

The invention provides a nanosheet-nanowire synergistically doped positive electrode material, a preparation method and a battery, the preparation method comprises the following steps: carrying out wet ball milling on a ternary precursor material, a nanowire material and a nanosheet material, and then drying to obtain a doped ternary precursor material; and mixing and sintering a lithium source and the doped ternary precursor material to obtain the nanosheet-nanowire synergistically doped positive electrode material. According to the preparation method disclosed by the invention, through the synergistic doping effect of the nanowire material and the nanosheet material, the problems of low lithium ion diffusion rate, poor structural stability, electrochemical performance degradation under high voltage and the like of the existing ternary positive electrode material are solved, and the comprehensive performance of the ternary positive electrode material is improved.

Description

Technical Field

[0001] This invention belongs to the field of battery technology and relates to a cathode material with synergistic nanosheet-nanowire doping, its preparation method, and a battery. Background Technology

[0002] With the ever-increasing demand for clean energy, improving the performance of lithium-ion batteries, as an important energy storage device, is crucial. Ternary cathode materials, due to their high specific capacity, good cycle stability, and moderate cost, have become one of the current research hotspots for lithium-ion battery cathode materials. However, ternary cathode materials still face some challenges in practical applications, such as slow lithium-ion diffusion rates, insufficient structural stability, and electrochemical performance degradation under high voltage, which limit their further development and application.

[0003] To address these issues, existing technologies typically employ modification methods such as elemental doping and surface coating for ternary cathode materials. While traditional elemental doping can improve structural stability through lattice manipulation, the doping elements are mostly randomly distributed in ionic form, making it difficult to form directional ion transport channels, thus limiting the improvement in lithium-ion diffusion rate. Nanostructured materials are commonly used as doping or coating materials in existing technologies. Compared to bulk micron-sized materials, nanoscale cathode materials can effectively reduce the lithium-ion transport distance, thereby accelerating the lithium-ion insertion / extraction rate and significantly improving the rate performance of lithium-ion batteries. Based on special structures composed of nanoparticles, such as nanorods, nanotubes, nanosheets, nanowires, and nanocones, these nanostructures can improve the structural stability and cycle stability of the material.

[0004] However, traditional carbon coating or single-phase nanomodification struggles to simultaneously achieve lithium-ion diffusion rate and structural stability. Single-material doping is prone to agglomeration, limiting performance improvement. While nanowire doping can construct one-dimensional ion transport pathways, the high aspect ratio of nanowires easily leads to agglomeration, increasing local impedance. Nanosheet doping, while providing a buffer against volume changes, suffers from easy stacking and agglomeration between sheets, resulting in a decrease in specific surface area and reduced electrolyte wetting area. Furthermore, existing solid-state methods struggle to produce materials with controllable morphology, uniform particle size, and stable electrochemical performance. Co-precipitation methods also face stringent experimental conditions, leading to tight packing of primary particles in the resulting microspheres, affecting electrolyte wetting and lithium-ion diffusion pathways, and reducing the capacity and rate performance of the electrode material. Summary of the Invention

[0005] The purpose of this invention is to provide a cathode material and preparation method of nanosheet-nanowire synergistic doping, and a battery. Through the synergistic doping effect of nanowire material and nanosheet material, the problems of slow lithium-ion diffusion rate, poor structural stability and electrochemical performance degradation under high voltage of existing ternary cathode materials are solved, thereby improving the overall performance of ternary cathode materials.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing a cathode material co-doped with nanosheets and nanowires, the preparation method comprising the following steps:

[0008] (1) Ternary precursor material, nanowire material and nanosheet material are wet ball milled and then dried to obtain doped ternary precursor material;

[0009] (2) The lithium source and the doped ternary precursor material described in step (1) are mixed and sintered to obtain the cathode material with synergistic doping of nanosheets and nanowires.

[0010] The nanowire and nanosheet materials of this invention possess unique one-dimensional and two-dimensional structures, respectively, and work synergistically. The one-dimensional structure of the nanowire material can construct directional ion transport channels, working in conjunction with the nanosheet material to form a highly efficient ion transport network within the material, significantly improving the diffusion rate of lithium ions and thus enhancing the rate performance of the battery. Meanwhile, the two-dimensional layered structure of the nanosheet material can effectively buffer the volume changes during charging and discharging, reducing structural stress. Together with the nanowire material, it enhances the overall structural stability of the material and improves its cycle life. Therefore, co-doping of nanosheet and nanowire materials can suppress agglomeration, effectively avoiding the agglomeration problem that easily occurs when doping with a single nanomaterial, ensuring the specific surface area and electrolyte wetting area of ​​the material, and thus improving the electrochemical activity of the material.

[0011] Furthermore, this invention first performs wet ball milling and drying on ternary precursor materials, nanowire materials, and nanosheet materials to prepare doped ternary precursor materials. Then, the lithium source and the doped ternary precursor materials are mixed and sintered. Compared with directly mixing, drying, and sintering ternary precursor materials, nanowire materials, nanosheet materials, and lithium source in a solid phase, the preparation method of this invention has a more superior doping effect, a more uniform composition distribution, and a more uniform particle size distribution.

[0012] Preferably, the diameter of the nanowire material in step (1) is in the range of 20nm-40nm, for example, it can be 20nm, 25nm, 30nm, 35nm or 40nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0013] If the diameter of the nanowire material in step (1) of this invention is less than 20 nm, it may become spheroidized or broken during sintering due to high surface energy. If the diameter of the nanowire material is greater than 40 nm, it will lose the nano effect, reduce the specific surface area, and weaken the one-dimensional ion channel effect.

[0014] Preferably, the length of the nanowire material in step (1) is in the range of 1μm-3μm, for example, it can be 1μm, 1.5μm, 2μm, 2.5μm or 3μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0015] If the length of the nanowire material described in this invention exceeds 3 μm, the risk of aggregation will increase significantly, and the local impedance will increase.

[0016] Preferably, the mass of the nanowire material in step (1) is 1wt%-3wt% of the mass of the ternary precursor material, for example, it can be 1wt%, 1.5wt%, 2wt%, 2.5wt% or 3wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] Preferably, the nanowire material in step (1) includes any one or a combination of at least two of titanium oxide nanowire materials, niobium oxide nanowire materials, or alumina nanowire materials.

[0018] The nanowire material selected in this invention has a stable structure at high temperatures (good compatibility with lithium salts and ternary precursor materials), does not participate in electrochemical reactions or has a low degree of participation, and has suitable ionic / electronic conduction characteristics.

[0019] Preferably, the thickness of the nanosheet material in step (1) is in the range of 5nm-15nm, for example, it can be 5nm, 7nm, 9nm, 11nm, 13nm or 15nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0020] If the thickness of the nanosheet material described in this invention is too thin, it will easily break or curl during ball milling and sintering, and the cost will increase dramatically. However, if the thickness of the nanosheet material is too thick, it will be difficult to take advantage of the two-dimensional material.

[0021] Preferably, the mass of the nanosheet material in step (1) is 0.5wt%-2wt% of the mass of the ternary precursor material, for example, it can be 0.5wt%, 1wt%, 1.5wt% or 2wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] Preferably, the nanosheet material in step (1) comprises boron nitride and / or niobium diselenide.

[0023] The nanosheet material described in this invention uses boron nitride and / or niobium diselenide. It is not suitable to use nanosheet materials such as MXene, graphene, molybdenum disulfide or tungsten disulfide, because these materials are unstable under high temperature conditions and are not suitable for subsequent high-temperature oxidation sintering processes. Therefore, they are not suitable for doping to prepare cathode materials.

[0024] Preferably, the chemical formula of the ternary precursor material in step (1) is Ni 1-y-z Co y Mn z (OH)2, where y is 0.05-0.2, for example, it can be 0.05, 0.1, 0.15 or 0.2, and z is 0.1-0.2, for example, it can be 0.1, 0.12, 0.14, 0.16, 0.18 or 0.2, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0025] Preferably, the ternary precursor material in step (1) is prepared by co-precipitation.

[0026] Preferably, the preparation method of the ternary precursor material in step (1) includes the following steps:

[0027] Nickel, cobalt, and manganese sources are prepared into metal salt solutions according to the formula (the concentration of the metal salt solution is 80-120 g / L, for example, 80 g / L, 90 g / L, 100 g / L, 110 g / L, or 120 g / L). The metal salt solution, complexing agent solution, and precipitant solution are added to the reaction vessel at the same time, and a co-precipitation reaction is carried out under the protection of protective gas. After a certain reaction time, the obtained material is washed and dried to obtain the ternary precursor material.

[0028] Preferably, the grinding balls used in the wet ball milling in step (1) include PTFE (polytetrafluoroethylene) balls.

[0029] This invention uses PTFE balls for wet ball milling. Because PTFE has low hardness and is chemically inert, it will hardly cause pollution or structural damage to the material, and can also ensure the uniform dispersion of the material.

[0030] Preferably, the solvent used in the wet ball milling in step (1) includes anhydrous ethanol.

[0031] Preferably, the ball-to-material ratio of the wet ball milling in step (1) is (5-10):1, for example, it can be 5:1, 7:1, 9:1 or 10:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0032] Preferably, the wet ball milling in step (1) is carried out under an inert atmosphere.

[0033] Preferably, the rotation speed of the wet ball mill in step (1) is 400rpm-500rpm, for example, 400rpm, 420rpm, 440rpm, 460rpm, 480rpm or 500rpm, and the time is 4h-6h, for example, 4h, 5h or 6h, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0034] Preferably, the drying method in step (1) includes vacuum drying.

[0035] Preferably, the drying temperature in step (1) is 60℃-120℃, for example, 60℃, 80℃, 100℃ or 120℃, and the time is 6h-24h, for example, 6h, 10h, 15h, 20h or 24h, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0036] Preferably, the sintering temperature in step (2) is 600℃-850℃, for example, 600℃, 650℃, 700℃, 750℃, 800℃ or 850℃, the time is 12h-20h, for example, 12h, 15h or 20h, and the heating rate is 3℃ / min-10℃ / min, for example, 3℃ / min, 5℃ / min, 7℃ / min or 10℃ / min, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0037] Preferably, the sintering atmosphere in step (2) is an oxygen atmosphere.

[0038] Preferably, the molar ratio of the total metal ions in the doped ternary precursor material in step (1) to the lithium ions in the lithium source in step (2) is 1:(1.03-1.06), for example, it can be 1:1.03, 1:1.04, 1:1.05 or 1:1.06, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] Preferably, the lithium salt in step (2) includes any one or a combination of at least two of lithium hydroxide, lithium carbonate, or lithium acetate.

[0040] Preferably, the mixing method in step (2) includes grinding.

[0041] In a second aspect, the present invention provides a cathode material co-doped with nanosheets and nanowires, wherein the cathode material co-doped with nanosheets and nanowires is prepared by the preparation method described in the first aspect.

[0042] Thirdly, the present invention provides a battery comprising a cathode material co-doped with nanosheets and nanowires as described in the second aspect.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] This invention addresses the shortcomings of single-dimensional modification by utilizing the synergistic doping effect of nanowire and nanosheet materials. One-dimensional nanowires provide longitudinal ion channels, while two-dimensional nanosheets enhance surface stability. Specifically, nanowires construct one-dimensional ion transport channels while leveraging the buffering effect of two-dimensional layered nanosheet structures to mitigate volume changes. This synergistic effect effectively solves the aggregation problem associated with single-dimensional nanomaterial doping, balancing lithium-ion diffusion rate and structural stability. Furthermore, this invention employs a specific preparation process, including wet ball milling, vacuum drying, and high-temperature sintering, to ensure controllable morphology and uniform particle size, thereby improving the electrochemical performance of the material. Detailed Implementation

[0045] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0046] Example 1

[0047] This embodiment provides a method for preparing a cathode material with synergistic nanosheet and nanowire doping, the method comprising the following steps:

[0048] (1) A metal salt solution with a concentration of 100 g / L was prepared by mixing nickel, cobalt, and manganese sources in a molar ratio of 8:1:1. This solution, along with a complexing agent solution and a precipitant solution, was added to the reactor simultaneously. A co-precipitation reaction was carried out under a protective gas atmosphere. After a certain reaction time, the resulting material was washed and dried to obtain a ternary precursor material (chemical formula Ni). 0.8 Co 0.1 Mn 0.1 (OH)2);

[0049] (2) The ternary precursor material, nanowire material (2wt% of the mass of the ternary precursor material) and nanosheet material (1wt% of the mass of the ternary precursor material) described in step (1) are added to a ball milling jar lined with polytetrafluoroethylene. Anhydrous ethanol is added as a solvent and PTFE balls are added as grinding balls for ball milling and mixing. The ball-to-material ratio is controlled at 10:1 and the rotation speed is 450 rpm. High-speed ball milling is carried out for 5 hours under an inert atmosphere. After uniform mixing, the mixture is vacuum dried at 100°C for 20 hours to form a doped ternary precursor material.

[0050] The nanowire material is titanium oxide nanowire, with a diameter in the range of 20nm-40nm and a length in the range of 1μm-3μm; the nanosheet material is boron nitride nanosheet, with a thickness in the range of 5nm-15nm.

[0051] (3) Then, the doped ternary precursor material described in step (2) and lithium hydroxide are ground thoroughly at a metal ion molar ratio of 1:1.03. The temperature is increased from room temperature to 800°C at a heating rate of 8°C / min in an oxygen atmosphere. After calcination and holding at this temperature for 18 hours, the material is naturally cooled to room temperature to obtain the nanosheet-nanowire co-doped cathode material.

[0052] Example 2

[0053] This embodiment provides a method for preparing a cathode material with synergistic nanosheet and nanowire doping, the method comprising the following steps:

[0054] (1) A metal salt solution with a concentration of 120 g / L was prepared by mixing nickel, cobalt and manganese sources in a molar ratio of 8:1:1. The solution was then added to the reactor along with the complexing agent solution and the precipitant solution. A co-precipitation reaction was carried out under the protection of a protective gas. After a certain reaction time, the resulting material was washed and dried to obtain a ternary precursor material (chemical formula Ni). 0.8 Co 0.1 Mn 0.1 (OH)2);

[0055] (2) The ternary precursor material, nanowire material (1 wt% of the mass of the ternary precursor material) and nanosheet material (2 wt% of the mass of the ternary precursor material) described in step (1) are added to a ball milling jar lined with polytetrafluoroethylene. Anhydrous ethanol is added as a solvent and PTFE balls are added as grinding balls for ball milling and mixing. The ball-to-material ratio is controlled at 5:1 and the rotation speed is 500 rpm. High-speed ball milling is carried out for 4 hours under an inert atmosphere. After uniform mixing, the mixture is vacuum dried at 120°C for 6 hours to form a doped ternary precursor material.

[0056] The nanowire material is titanium oxide nanowire, with a diameter in the range of 20-40 nm and a length in the range of 1 μm-3 μm; the nanosheet material is boron nitride nanosheet, with a thickness in the range of 5 nm-15 nm.

[0057] (3) Then, the doped ternary precursor material described in step (2) and lithium hydroxide are ground thoroughly at a metal ion molar ratio of 1:1.05. The temperature is increased from room temperature to 600°C at a heating rate of 3°C / min in an oxygen atmosphere. After calcination and holding at this temperature for 20 hours, the material is naturally cooled to room temperature to obtain the nanosheet-nanowire co-doped cathode material.

[0058] Example 3

[0059] This embodiment provides a method for preparing a cathode material with synergistic nanosheet and nanowire doping, the method comprising the following steps:

[0060] (1) Prepare a metal salt solution with a concentration of 80 g / L by mixing nickel source, cobalt source and manganese source in a molar ratio of 7:1.5:1.5. Add the solution to the reaction vessel along with the complexing agent solution and the precipitant solution. Carry out a co-precipitation reaction under the protection of a protective gas. After a certain reaction time, wash and dry the obtained material to obtain the ternary precursor material (chemical formula Ni 0.7 Co 0.15 Mn 0.15 (OH)2);

[0061] (2) The ternary precursor material, nanowire material (3wt% of the mass of the ternary precursor material) and nanosheet material (0.5wt% of the mass of the ternary precursor material) described in step (1) are added to a ball milling jar lined with polytetrafluoroethylene. Anhydrous ethanol is added as a solvent and PTFE balls are added as grinding balls for ball milling and mixing. The ball-to-material ratio is controlled at 8:1 and the rotation speed is 400 rpm. High-speed ball milling is carried out for 6 hours under an inert atmosphere. After uniform mixing, the mixture is vacuum dried at 80°C for 24 hours to form a doped ternary precursor material.

[0062] The nanowire material is niobium oxide nanowire, with a diameter in the range of 30nm-40nm and a length in the range of 2μm-3μm; the nanosheet material is niobium diselenide nanosheet, with a thickness in the range of 5nm-15nm.

[0063] (3) Subsequently, the doped ternary precursor material described in step (2) and lithium hydroxide are thoroughly ground in a metal ion molar ratio of 1:1.06. The temperature is increased from room temperature to 850°C at a heating rate of 10°C / min in an oxygen atmosphere. After calcination and holding at this temperature for 12 hours, the material is naturally cooled to room temperature to obtain the nanosheet-nanowire co-doped cathode material.

[0064] Example 4

[0065] This embodiment provides a method for preparing a cathode material with synergistic doping of nanosheets and nanowires. The preparation method is the same as in Example 1, except that the PTFE balls in step (2) are replaced with zirconium balls as grinding balls.

[0066] Example 5

[0067] This embodiment provides a method for preparing a cathode material with synergistic doping of nanosheets and nanowires. Except for the diameter of the nanowire material in step (2) being in the range of 5-15 nm, the preparation method is the same as that in Example 1.

[0068] Example 6

[0069] This embodiment provides a method for preparing a cathode material with synergistic doping of nanosheets and nanowires. Except for the nanowire material in step (2) having a diameter in the range of 45-60 nm, the preparation method is the same as in Example 1.

[0070] Example 7

[0071] This embodiment provides a method for preparing a cathode material with synergistic doping of nanosheets and nanowires. Except for step (2), in which the length of the nanowire material is in the range of 4μm-5μm, the preparation method is the same as in Example 1.

[0072] Example 8

[0073] This embodiment provides a method for preparing a cathode material with synergistic doping of nanosheets and nanowires. Except for the thickness of the nanosheet material in step (2) being in the range of 1 nm to 4 nm, the preparation method is the same as that in Example 1.

[0074] Example 9

[0075] This embodiment provides a method for preparing a cathode material with synergistic doping of nanosheets and nanowires. Except for step (2), where the thickness of the nanosheet material is in the range of 20nm-30nm, the preparation method is the same as in embodiment 1.

[0076] Comparative Example 1

[0077] This comparative example provides a method for preparing a cathode material. Except for step (2), in which nanosheet material is not added, the preparation method is the same as in Example 1.

[0078] Comparative Example 2

[0079] This comparative example provides a method for preparing a cathode material. The preparation method is the same as that in Example 1, except that nanowire material is not added in step (2).

[0080] Comparative Example 3

[0081] This comparative example provides a method for preparing a cathode material. Except for step (2), in which the ternary precursor material, nanowire material, nanosheet material and lithium hydroxide are directly ground in step (3) and then calcined, the preparation method is the same as in Example 1.

[0082] The cathode materials obtained in the above embodiments and comparative examples were used to prepare cathode sheets. The specific steps are as follows:

[0083] Preparation of positive electrode slurry: The positive electrode material, conductive agent acetylene black and binder polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 90:5:5. N-methylpyrrolidone (NMP) is added as a solvent and stirred in a vacuum mixer for 4 hours to form a uniform slurry.

[0084] Coating and drying: The slurry is coated onto the aluminum foil current collector with a coating thickness of approximately 100 μm, and then vacuum dried at 80 °C for 12 hours to remove the solvent.

[0085] Compressing and stamping: The dried electrode sheets are compacted using a roller press under a pressure of 10MPa, and then punched into round sheets with a diameter of 12mm, which serve as positive electrode sheets.

[0086] Battery assembly: In an argon-protected glove box (with water and oxygen content below 0.1 ppm), coin cells were assembled using lithium metal sheets as the negative electrode, a polypropylene separator (Celgard 2400), and an electrolyte (containing 1 mol / L lithium hexafluorophosphate, with ethylene carbonate and diethyl carbonate in a volume ratio of 1:1) as the solvent.

[0087] The electrochemical performance of coin cells was tested under the following conditions:

[0088] Charge / discharge test: A constant current charge / discharge test was performed using a battery testing system (such as Neware BTS-4000) within a voltage range of 2.8-4.3V. The first charge / discharge was performed to activate the battery at a rate of 0.1C (1C=200mA / g), followed by a cycle performance test at a rate of 0.2C for 100 cycles at a test temperature of 25℃.

[0089] Capacity retention rate calculation: Capacity retention rate (%) = (Discharge capacity of the 100th cycle / Discharge capacity of the 1st cycle) × 100%.

[0090] After completing 100 cycles at 0.2C, the battery was charged and discharged at different rates (0.2C, 0.5C, 1C, 2C, 5C), with 5 cycles at each rate. The discharge capacity at the high rate of 5C was recorded. The rate performance was calculated using the formula: 5C capacity retention (%) = (Discharge capacity at 5C rate / Initial discharge capacity at 0.2C rate) × 100%.

[0091] The test results are shown in Table 1 below:

[0092] Table 1

[0093]

[0094] As can be seen from Table 1 above:

[0095] As shown in Examples 1 and Comparative Examples 1-2, the present invention effectively solves the agglomeration problem of single nanomaterial doping through the synergistic doping effect of nanowires and nanosheets, balancing lithium-ion diffusion rate and structural stability, and improving the overall performance of the battery. As shown in Examples 1 and Comparative Example 3, the present invention first prepares a doped ternary precursor material by wet ball milling and drying of ternary precursor material, nanowire material, and nanosheet material, and then mixes and sinters the lithium source and the doped ternary precursor material, which can improve the doping effect and further improve battery performance. As shown in Examples 1 and 4, the present invention preferably uses PTFE balls with low hardness and high chemical inertness as grinding balls for ball milling. As shown in Examples 1 and 5-7, the diameter and length of the nanowire material of the present invention are preferably within a suitable range, otherwise it will affect the performance of the nanowire material. As shown in Examples 1 and 8-9, the thickness of the nanosheet material of the present invention affects the performance of the nanosheet material, and is preferably within a suitable range.

[0096] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a cathode material with synergistic nanosheet-nanowire doping, characterized in that, The preparation method includes the following steps: (1) Ternary precursor material, nanowire material and nanosheet material are wet ball milled and then dried to obtain doped ternary precursor material; (2) The lithium source and the doped ternary precursor material described in step (1) are mixed and sintered to obtain the cathode material with synergistic doping of nanosheets and nanowires.

2. The preparation method according to claim 1, characterized in that, The diameter of the nanowire material in step (1) is in the range of 20 nm to 40 nm; Preferably, the length of the nanowire material in step (1) is in the range of 1 μm to 3 μm; Preferably, the mass of the nanowire material in step (1) is 1wt%-3wt% of the mass of the ternary precursor material; Preferably, the nanowire material in step (1) includes any one or a combination of at least two of titanium oxide nanowire materials, niobium oxide nanowire materials, or alumina nanowire materials.

3. The preparation method according to claim 1 or 2, characterized in that, The thickness of the nanosheet material in step (1) is in the range of 5 nm to 15 nm; Preferably, the mass of the nanosheet material in step (1) is 0.5wt%-2wt% of the mass of the ternary precursor material; Preferably, the nanosheet material in step (1) comprises boron nitride and / or niobium diselenide.

4. The preparation method according to claim 1 or 2, characterized in that, The general chemical formula of the ternary precursor material in step (1) is Ni 1-y-z Co y Mn z (OH)2, where y is 0.05-0.2 and z is 0.1-0.2; Preferably, the ternary precursor material in step (1) is prepared by co-precipitation.

5. The preparation method according to claim 1 or 2, characterized in that, The grinding balls used in the wet ball milling in step (1) include PTFE balls; Preferably, the solvent used in the wet ball milling in step (1) includes anhydrous ethanol; Preferably, the ball-to-material ratio in the wet ball milling in step (1) is (5-10):1; Preferably, the wet ball milling in step (1) is performed at a speed of 400 rpm to 500 rpm for 4 h to 6 h.

6. The preparation method according to claim 1 or 2, characterized in that, The drying method described in step (1) includes vacuum drying; Preferably, the drying temperature in step (1) is 60℃-120℃ and the time is 6h-24h.

7. The preparation method according to claim 1 or 2, characterized in that, The sintering temperature in step (2) is 600℃-850℃, the time is 12h-20h, and the heating rate is 3℃ / min-10℃ / min; Preferably, the sintering atmosphere in step (2) is an oxygen atmosphere.

8. The preparation method according to claim 1 or 2, characterized in that, The molar ratio of the total metal ions in the doped ternary precursor material in step (1) to the lithium ions in the lithium source in step (2) is 1:(1.03-1.06); Preferably, the lithium salt in step (2) includes any one or a combination of at least two of lithium hydroxide, lithium carbonate, or lithium acetate; Preferably, the mixing method in step (2) includes grinding.

9. A cathode material co-doped with nanosheets and nanowires, characterized in that, The nanosheet-nanowire co-doped cathode material is prepared by the preparation method described in any one of claims 1-8.

10. A battery, characterized in that, The battery comprises a cathode material co-doped with nanosheets and nanowires as described in claim 9.

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