Positive electrode material containing Li2ZrO3 coating layer, preparation method of positive electrode material, positive electrode plate and battery

Abstract

The invention provides a positive electrode material containing a Li2ZrO3 coating layer, a preparation method of the positive electrode material, a positive electrode plate and a battery. The positive electrode material comprises a single-crystal ultra-high nickel positive electrode material and the Li2ZrO3 coating layer coating the single-crystal ultra-high nickel positive electrode material. The positive electrode material is composed of a single-crystal ultrahigh-nickel positive electrode material and a Li2ZrO3 coating layer, the Li2ZrO3 coating layer blocks nickel dissolution and diffusion, promotes uniform de-intercalation of lithium ions, and relieves lithium / nickel mixed discharge; meanwhile, the coating layer isolates direct contact between the electrolyte and the single-crystal ultrahigh-nickel positive electrode material, so that the oxygenolysis side reaction of the electrolyte is reduced; the specific surface area is reduced due to the large-grain characteristic of the single-crystal material, exposure of active sites is reduced by cooperating with the coating layer, and the interface side reaction is further inhibited; in addition, single crystal complete crystal lattices can uniformly disperse stress in the lithium deintercalation process, and the coating layer limits the degree of freedom of expansion / contraction of the material through mechanical constraint, so that lattice distortion and volume contraction are synergistically inhibited.

Description

Technical Field

[0001] The present invention belongs to the field of battery technology and relates to a positive electrode material comprising a Li2ZrO3 coating layer, and in particular to a positive electrode material comprising a Li2ZrO3 coating layer and a preparation method thereof, a positive electrode sheet and a battery. Background Art

[0002] Lithium-ion batteries, with their high energy density and long cycle life, have found widespread application in electric vehicles, portable electronic devices, and energy storage systems. As a core component of batteries, the performance of the cathode material directly determines the battery's energy density and cycle life. In recent years, single-crystal ultrahigh nickel layered oxides have become a research hotspot due to their high specific capacity.

[0003] However, single-crystal ultra-high nickel materials face many challenges in the preparation process. These challenges include the need to carry out the preparation process at a high calcination temperature, which easily leads to lithium / nickel mixing; the particle size of the prepared single-crystal ultra-high nickel material is too small, which will trigger interfacial side reactions; and the prepared single-crystal ultra-high nickel material will undergo significant material volume shrinkage during the cycle process, thereby accelerating the performance degradation of the battery.

[0004] CN108878865A discloses a coated high-nickel cathode material for lithium-ion batteries and its preparation method. This disclosure provides a high-nickel cathode material for lithium-ion batteries and its preparation method. The high-nickel cathode material is mechanically finely ground into primary particles, which are then added to an aluminum-containing organic solution, a titanium-containing organic solution, or a zirconium-containing organic solution. After uniform mixing, the mixture is spray-dried in a closed cycle. The dried mixture is sintered to obtain a high-nickel cathode material in which both the primary and secondary particles are coated with a lithium-ion conductor compound. However, this coated high-nickel cathode material for lithium-ion batteries suffers from poor interfacial stability.

[0005] CN112952049A discloses a method for repairing the surface structure of a high-nickel cathode material, the resulting high-nickel cathode material, and a lithium-ion battery. The method comprises: 1) mixing the high-nickel cathode material, a first lithium source, and a metal oxide, followed by sintering to obtain a sintered product; 2) mixing the sintered product with an acid solution and reacting it, followed by evaporation and sintering to obtain a high-nickel cathode material with a repaired surface structure. However, this high-nickel cathode material suffers from poor interfacial stability and severe lithium / nickel mixing, resulting in reduced electrochemical performance.

[0006] The single-crystal ultra-high nickel cathode materials disclosed in the prior art all have certain drawbacks, including severe lithium / nickel mixing, severe interfacial side reactions, and prone to volume shrinkage during cycling. This results in poor cycling performance for batteries made with these single-crystal ultra-high nickel cathode materials. Therefore, the development and design of a novel cathode material containing a Li2ZrO3 coating, its preparation method, cathode plate, and battery are crucial. Summary of the Invention

[0007] In response to the deficiencies in the prior art, the present invention aims to provide a positive electrode material comprising a Li2ZrO3 coating layer, a preparation method thereof, a positive electrode plate and a battery. The positive electrode material provided by the present invention is composed of a single crystal ultra-high nickel positive electrode material and a Li2ZrO3 coating layer. The single crystal structure has no grain boundaries, which blocks the migration path of nickel ions to the lithium layer, while the Li2ZrO3 coating layer blocks the dissolution and diffusion of nickel, promotes the uniform deintercalation of lithium ions, and alleviates lithium / nickel mixing. At the same time, the coating layer physically isolates the direct contact between the electrolyte and the single crystal ultra-high nickel positive electrode material, reducing the dissolution of transition metals and the oxidation and decomposition side reactions of the electrolyte. The large grain characteristics of the single crystal material reduce the specific surface area, and cooperate with the coating layer to reduce the exposure of active sites, further inhibiting interfacial side reactions. In addition, the complete lattice of the single crystal can evenly disperse the stress during the lithium deintercalation process, and the coating layer limits the expansion / contraction freedom of the material through mechanical constraints, thereby synergistically inhibiting lattice distortion and volume shrinkage.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a positive electrode material comprising a Li2ZrO3 coating layer, wherein the positive electrode material comprises a single crystal ultrahigh nickel positive electrode material and a Li2ZrO3 coating layer coated on the outside of the single crystal ultrahigh nickel positive electrode material.

[0010] The positive electrode material provided by the present invention includes a single-crystal ultra-high nickel positive electrode material and a Li2ZrO3 coating layer. The single-crystal ultra-high nickel material has no grain boundaries, which reduces the path for nickel ions to migrate to the lithium layer, while the Li2ZrO3 coating layer prevents nickel from dissolving and diffusing to the lithium site through surface defect passivation and oxygen vacancy suppression; in addition, the Li2ZrO3 coating layer acts as a chemical barrier, reducing surface reconstruction caused by electrolyte corrosion. At the same time, the Li2ZrO3 in the Li2ZrO3 coating layer acts as a fast ion conductor, which promotes uniform deintercalation of lithium ions and weakens the driving force for nickel migration, thereby significantly alleviating lithium / nickel mixing.

[0011] The positive electrode material provided by the present invention includes a single crystal ultra-high nickel positive electrode material and a Li2ZrO3 coating layer. The Li2ZrO3 coating layer physically isolates the single crystal ultra-high nickel positive electrode material from direct contact with the electrolyte, thereby reducing the dissolution of transition metals in the single crystal ultra-high nickel positive electrode material and the oxidative decomposition of the electrolyte; in addition, compared with polycrystalline, the large grains of the single crystal ultra-high nickel positive electrode material significantly reduce the specific surface area of the positive electrode material, reduce the exposure of active sites, and cooperate with the effect of the coating layer to reduce interfacial side reactions.

[0012] The positive electrode material provided by the present invention includes a single-crystal ultra-high nickel positive electrode material and a Li2ZrO3 coating layer. Since the single-crystal ultra-high nickel positive electrode material has no grain boundaries, its complete lattice can evenly disperse the stress during the lithium insertion and extraction process; in addition, the Li2ZrO3 coating layer limits the expansion and contraction of the single-crystal ultra-high nickel positive electrode material through physical constraints; in addition, the Li2ZrO3 in the Li2ZrO3 coating layer promotes the uniform insertion and extraction of lithium ions, avoiding the severe lattice deformation caused by local lithium concentration gradients.

[0013] In summary, the positive electrode material provided by the present invention is composed of a single crystal ultra-high nickel positive electrode material and a Li2ZrO3 coating layer; the single crystal structure has no grain boundaries, which blocks the migration path of nickel ions to the lithium layer, while the Li2ZrO3 coating layer blocks the dissolution and diffusion of nickel, promotes the uniform deintercalation of lithium ions, and alleviates lithium / nickel mixing; at the same time, the coating layer physically isolates the direct contact between the electrolyte and the single crystal ultra-high nickel positive electrode material, reducing the dissolution of transition metals and the oxidation and decomposition side reactions of the electrolyte; the large grain characteristics of the single crystal material reduce the specific surface area, and the coating layer cooperates to reduce the exposure of active sites, further inhibiting the interface side reactions; in addition, the complete lattice of the single crystal can evenly disperse the stress during the lithium deintercalation process, and the coating layer limits the expansion / contraction freedom of the material through mechanical constraints, thereby synergistically inhibiting lattice distortion and volume shrinkage. Therefore, the battery prepared with the positive electrode material provided by the present invention has excellent cycle stability.

[0014] Preferably, based on the mass of the positive electrode material, the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.08-0.32wt%, for example, it can be 0.08wt%, 0.10wt%, 0.12wt%, 0.14wt%, 0.16wt%, 0.18wt%, 0.20wt%, 0.22wt%, 0.24wt%, 0.26wt%, 0.28wt%, 0.30wt% or 0.32wt%, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0015] In the present invention, by limiting the coating layer containing Li2ZrO3 to consist only of Li2ZrO3, and the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.08-0.32wt%, the positive electrode material can accelerate lithium ion migration, reduce transition metal dissolution and SEI film degradation, thereby making the positive electrode material have higher interface stability, and thus making the battery prepared with the positive electrode material have better cycle stability.

[0016] Preferably, the chemical formula of the single crystal ultra-high nickel cathode material is Ni x Co y Mn z O2; wherein, x is 0.85 to 0.95, y is 0.035 to 0.075, z is 0.015 to 0.075, and x+y+z=1.

[0017] In the present invention, x is 0.85 to 0.95, for example, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94 or 0.95, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0018] In the present invention, y is 0.035 to 0.075, for example, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070 or 0.075, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0019] In the present invention, z is 0.015 to 0.075, for example, it can be 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070 or 0.075, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0020] Preferably, the D50 particle size of the positive electrode material is 0.5 to 1.0 μm, for example, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1.0 μm, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0021] In the present invention, by limiting the D50 particle size of the positive electrode material to 0.5-1.0 μm, the positive electrode material has a higher grain size and thus has a lower specific surface area, thereby effectively further suppressing the interface side reaction of the positive electrode material.

[0022] In a second aspect, the present invention provides a method for preparing the positive electrode material according to the first aspect, the preparation method comprising:

[0023] The single crystal ultra-high nickel cathode material is mixed with Li2ZrO3 and then heat treated in an oxygen-containing atmosphere to obtain a cathode material.

[0024] In the preparation method provided by the present invention, the coating and heat treatment processes of the Li2ZrO3 coating layer are simultaneously achieved in a one-step method, which simplifies the process flow, reduces energy consumption and production costs, and is more suitable for large-scale production.

[0025] Preferably, the method for preparing the single crystal ultra-high nickel positive electrode material comprises:

[0026] A precursor solution containing nickel ions, manganese ions and cobalt ions is spray-pyrolyzed to obtain a precursor; the obtained precursor is then mixed with a lithium source and calcined in an oxygen-containing atmosphere to obtain a single-crystal ultra-high nickel positive electrode material.

[0027] In the present invention, single-crystal ultra-high nickel positive electrode material is prepared by limited spray pyrolysis, and then mixed with Li2ZrO3 and then heat treated, which not only optimizes the grain size and interface stability, but also significantly improves the electrochemical performance of the material.

[0028] Preferably, the total metal ion concentration in the precursor solution is 0.5 to 2.5 mol / L, for example, it can be 0.5 mol / L, 0.8 mol / L, 1.0 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L, 2.0 mol / L, 2.2 mol / L or 2.5 mol / L, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0029] Preferably, the molar ratio of nickel ions, manganese ions and cobalt ions in the precursor solution is (0.85-0.95):(0.035-0.075):(0.015-0.075).

[0030] Preferably, the precursor solution contains nickel salt, manganese salt and cobalt salt.

[0031] The nickel salt, manganese salt and cobalt salt described in the present invention independently include any one of chloride, sulfate, nitrate, acetate or citrate, or a combination of at least two of them. Typical but non-limiting combinations include a combination of chloride and sulfate, a combination of nitrate and acetate, a combination of sulfate and citrate, a combination of chloride, nitrate and acetate, or a combination of sulfate, acetate and citrate.

[0032] Preferably, the spray pyrolysis comprises atomization and pyrolysis performed sequentially.

[0033] Preferably, the atomizing gas flow rate during atomization in the spray pyrolysis is 20 to 30 m / s. 3 / h, for example, it can be 20m 3 / h、21m 3 / h、22m 3 / h、23m 3 / h、24m 3 / h、25m 3 / h、26m 3 / h、27m 3 / h、28m 3 / h、29m 3 / h or 30m 3 / h, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0034] Preferably, the atomizing gas during atomization in the spray pyrolysis comprises nitrogen and air in a volume ratio of (3 to 5):1. The volume ratio of nitrogen to air can be, for example, 3:1, 3.2:1, 3.5:1, 3.8:1, 4:1, 4.2:1, 4.5:1, 4.8:1 or 5:1, but is not limited to the listed values. Other values not listed within this numerical range are also applicable.

[0035] Preferably, the atomization angle during atomization in the spray pyrolysis is 20 to 60°, for example, it can be 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55° or 60°, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0036] Preferably, in the spray pyrolysis, the temperature of the upper section of the spray pyrolysis roasting furnace is 200-400°C, and the temperature of the lower section of the spray pyrolysis roasting furnace is 800-1200°C.

[0037] In the present invention, the temperature of the upper section of the spray pyrolysis calciner in the spray pyrolysis is 200-400°C, for example, it can be 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, 320°C, 340°C, 360°C, 380°C or 400°C, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0038] In the present invention, the temperature of the lower section of the spray pyrolysis calcining furnace in the spray pyrolysis is 800-1200°C, for example, it can be 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C or 1200°C, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0039] Preferably, the total residence time of the precursor solution in the spray pyrolysis furnace during the spray pyrolysis is 5 to 12 s, for example, 5 s, 6 s, 7 s, 8 s, 9 s, 10 s, 11 s or 12 s, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0040] In the present invention, the total residence time of the precursor solution in the spray pyrolysis roasting furnace refers to the total residence time of the precursor droplets (tiny droplets after the precursor solution is atomized) in the entire spray pyrolysis roasting furnace, that is, the entire process time from the droplets entering the roasting furnace entrance to the final discharge from the furnace body, specifically including the following stages:

[0041] The atomized precursor droplets enter the calciner: The precursor droplets first enter the upper section of the spray pyrolysis calciner (temperature is 200-400°C), at which stage the rapid evaporation of the solvent, the initial drying of the precursor and partial decomposition are completed;

[0042] The precursor droplets after preliminary drying and partial decomposition fall into the high-temperature zone: The precursor droplets after preliminary drying and partial decomposition enter the lower section of the spray pyrolysis roasting furnace (temperature is 800-1200℃), where they complete complete pyrolysis, crystallization and particle formation;

[0043] Final product discharge: The pyrolysis products are discharged from the spray pyrolysis roasting furnace with air flow or gravity.

[0044] Preferably, the lithium source includes any one or a combination of at least two of lithium hydroxide, lithium carbonate, lithium hydroxide hydrate or lithium carbonate hydrate. Typical but non-limiting combinations include a combination of lithium hydroxide and lithium carbonate, a combination of lithium hydroxide and lithium hydroxide hydrate, a combination of lithium carbonate and lithium carbonate hydrate, a combination of lithium hydroxide, lithium carbonate and lithium hydroxide hydrate, or a combination of lithium hydroxide, lithium carbonate, lithium hydroxide hydrate and lithium carbonate hydrate.

[0045] Preferably, the oxygen-containing atmosphere comprises an air atmosphere.

[0046] Preferably, the calcination includes a first heating and a first heat preservation performed sequentially.

[0047] Preferably, the first heating rate is 1 to 10°C / min, for example, it can be 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min or 10°C / min, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0048] Preferably, the temperature of the first insulation is 800-900° C., and the time is 10-14 hours.

[0049] The temperature of the first insulation in the present invention is 800-900°C, for example, it can be 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C or 900°C, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0050] The first insulation time in the present invention is 10 to 14 hours, for example, it can be 10 hours, 10.5 hours, 11 hours, 11.5 hours, 12 hours, 12.5 hours, 13 hours, 13.5 hours or 14 hours, but is not limited to the listed values. Other unlisted values within the numerical range are also applicable.

[0051] Preferably, the calcination further includes natural cooling.

[0052] Preferably, the mixing method includes ball milling.

[0053] Preferably, the ball-to-material ratio of the ball mill is (5-15):1, the rotation speed is 100-500 rpm, and the time is 1-3 hours.

[0054] The ball-to-material ratio of the ball mill described in the present invention is (5-15):1, for example, it can be 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1 or 15:1, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0055] The rotation speed of the ball mill in the present invention is 100 to 500 rpm, for example, it can be 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm or 500 rpm, but is not limited to the listed values. Other values not listed within the numerical range are also applicable.

[0056] The ball milling time in the present invention is 1 to 3 hours, for example, it can be 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3 hours, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0057] Preferably, the oxygen-containing atmosphere comprises an air atmosphere.

[0058] Preferably, the heat treatment includes a second heating and a second heat preservation performed sequentially.

[0059] Preferably, the second heating rate is 1 to 10°C / min, for example, it can be 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min or 10°C / min, but is not limited to the listed values, and other unlisted values within this numerical range are also applicable.

[0060] Preferably, the second insulation temperature is 600-700° C., and the time is 3-7 hours.

[0061] In the present invention, the temperature of the second insulation is 600-700°C, for example, it can be 600°C, 610°C, 620°C, 630°C, 640°C, 650°C, 660°C, 670°C, 680°C, 690°C or 700°C, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0062] In the present invention, the second insulation time is 3 to 7 hours, for example, it can be 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours or 7 hours, but is not limited to the listed values. Other values not listed within the numerical range are also applicable.

[0063] Preferably, the heat treatment further includes natural cooling.

[0064] As a preferred technical solution of the preparation method of the present invention, the preparation method comprises:

[0065] (1) spray pyrolysis of a precursor solution containing nickel ions, manganese ions, and cobalt ions to obtain a precursor;

[0066] The total metal ion concentration in the precursor solution is 0.5-2.5 mol / L, and the molar ratio of nickel ion, manganese ion and cobalt ion is (0.85-0.95):(0.035-0.075):(0.015-0.075);

[0067] The spray pyrolysis includes atomization and pyrolysis performed in sequence; the atomization gas flow rate during atomization is 20 to 30 m 3 / h, the atomizing gas is composed of nitrogen and air in a volume ratio of (3-5):1, and the atomization angle is 20-60°; the temperature of the upper section of the spray pyrolysis furnace in the spray pyrolysis is 200-400°C, and the temperature of the lower section of the spray pyrolysis furnace is 800-1200°C; the total residence time of the precursor solution in the spray pyrolysis furnace in the spray pyrolysis is 5-12s;

[0068] (2) mixing the precursor obtained in step (1) with a lithium source, heating the mixture to 800-900° C. at a rate of 1-10° C. / min in an air atmosphere, maintaining the temperature for 10-14 hours, and then cooling the mixture naturally to obtain a single crystal ultrahigh nickel cathode material;

[0069] (3) The single crystal ultrahigh nickel positive electrode material and Li2ZrO3 are mixed by ball milling with a ball-to-material ratio of (5-15):1, a rotation speed of 100-500 rpm and a time of 1-3 hours, and the obtained mixture is heated to 600-700°C at a rate of 1-10°C / min in an air atmosphere and then kept warm for 3-7 hours to obtain the positive electrode material.

[0070] In a third aspect, the present invention provides a positive electrode plate, which includes the positive electrode material described in the first aspect.

[0071] In a fourth aspect, the present invention provides a battery comprising the positive electrode sheet described in the third aspect.

[0072] The numerical range described in the present invention includes not only the point values listed above, but also any point values between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values included in the range.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] The positive electrode material provided by the present invention is composed of a single crystal ultra-high nickel positive electrode material and a Li2ZrO3 coating layer; the single crystal structure has no grain boundaries, blocking the migration path of nickel ions to the lithium layer, while the Li2ZrO3 coating layer blocks nickel dissolution and diffusion, promotes uniform lithium ion deintercalation, and alleviates lithium / nickel mixing; at the same time, the coating layer physically isolates the direct contact between the electrolyte and the single crystal ultra-high nickel positive electrode material, reducing transition metal dissolution and electrolyte oxidation and decomposition side reactions; the large grain characteristics of the single crystal material reduce the specific surface area, and cooperate with the coating layer to reduce the exposure of active sites, further inhibiting interfacial side reactions; in addition, the complete lattice of the single crystal can evenly disperse the stress during lithium deintercalation, and the coating layer limits the material's expansion / contraction freedom through mechanical constraints, thereby synergistically inhibiting lattice distortion and volume shrinkage. Therefore, the battery prepared with the positive electrode material provided by the present invention has excellent cycle stability. DETAILED DESCRIPTION

[0075] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0076] Example 1

[0077] This embodiment provides a positive electrode material (D50 particle size is 0.8 μm) comprising a Li2ZrO3 coating layer, wherein the positive electrode material comprises a single crystal ultra-high nickel positive electrode material (chemical formula is Ni 0.9 Co 0.055 Mn 0.045 O2), and a Li2ZrO3 coating layer coated on the outside of the single crystal ultra-high nickel positive electrode material;

[0078] Based on the mass of the positive electrode material, the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.20wt%;

[0079] The preparation method of the positive electrode material is:

[0080] (1) spray pyrolysis of a precursor solution containing nickel ions, manganese ions, and cobalt ions to obtain a precursor;

[0081] The total metal ion concentration in the precursor solution is 1.5 mol / L, and the molar ratio of nickel ion, manganese ion and cobalt ion is 0.9:0.055:0.045;

[0082] The spray pyrolysis includes atomization and pyrolysis performed in sequence; the atomization gas flow rate during atomization is 25m 3 / h, the atomizing gas consists of nitrogen and air in a volume ratio of 4:1, and the atomization angle is 30°; the temperature of the upper section of the spray pyrolysis furnace in the spray pyrolysis is 350°C, and the temperature of the lower section of the spray pyrolysis furnace is 850°C; the total residence time of the precursor solution in the spray pyrolysis furnace in the spray pyrolysis is 8s;

[0083] (2) mixing the precursor obtained in step (1) with a lithium source, heating the mixture to 850° C. at a rate of 6° C. / min in an air atmosphere, maintaining the temperature for 12 h, and then cooling the mixture naturally to obtain a single crystal ultrahigh nickel cathode material;

[0084] (3) The single crystal ultrahigh nickel positive electrode material and Li2ZrO3 were mixed by ball milling at a ball-to-material ratio of 10:1, a rotation speed of 300 rpm, and a time of 6 h. The resulting mixture was heated to 650°C at a rate of 6°C / min in an air atmosphere and then kept warm for 5 h to obtain the positive electrode material.

[0085] Example 2

[0086] This embodiment provides a positive electrode material (D50 particle size is 0.6 μm) comprising a Li2ZrO3 coating layer, wherein the positive electrode material comprises a single crystal ultra-high nickel positive electrode material (chemical formula is Ni 0.9 Co 0.055 Mn 0.045 O2), and a Li2ZrO3 coating layer coated on the outside of the single crystal ultra-high nickel positive electrode material;

[0087] Based on the mass of the positive electrode material, the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.26wt%;

[0088] The preparation method of the positive electrode material is:

[0089] (1) spray pyrolysis of a precursor solution containing nickel ions, manganese ions, and cobalt ions to obtain a precursor;

[0090] The total metal ion concentration in the precursor solution is 1 mol / L, and the molar ratio of nickel ion, manganese ion and cobalt ion is 0.9:0.055:0.045;

[0091] The spray pyrolysis includes sequential atomization and pyrolysis; the atomizing gas flow rate during atomization is 13 L / min, the atomizing gas is composed of nitrogen and air in a volume ratio of 3.5:1, and the atomization angle is 50°; the temperature of the upper section of the spray pyrolysis furnace during the spray pyrolysis is 250°C, and the temperature of the lower section of the spray pyrolysis furnace is 1000°C; the total residence time of the precursor solution in the spray pyrolysis furnace during the spray pyrolysis is 7 seconds;

[0092] (2) mixing the precursor obtained in step (1) with a lithium source, heating the mixture to 880° C. at a rate of 8° C. / min in an air atmosphere, maintaining the temperature for 11 h, and then naturally cooling the mixture to obtain a single crystal ultrahigh nickel cathode material;

[0093] (3) The single crystal ultrahigh nickel positive electrode material and Li2ZrO3 were mixed by ball milling with a ball-to-material ratio of 12:1, a rotation speed of 200 rpm and a time of 2.5 h. The obtained mixture was heated to 670°C at a rate of 8°C / min in an air atmosphere and then kept warm for 4 h to obtain the positive electrode material.

[0094] Example 3

[0095] This embodiment provides a positive electrode material (D50 particle size is 0.9 μm) comprising a Li2ZrO3 coating layer, wherein the positive electrode material comprises a single crystal ultra-high nickel positive electrode material (chemical formula is Ni 0.9 Co 0.055 Mn 0.045 O2), and a Li2ZrO3 coating layer coated on the outside of the single crystal ultra-high nickel positive electrode material;

[0096] Based on the mass of the positive electrode material, the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.14wt%;

[0097] The preparation method of the positive electrode material is:

[0098] (1) spray pyrolysis of a precursor solution containing nickel ions, manganese ions, and cobalt ions to obtain a precursor;

[0099] The total metal ion concentration in the precursor solution is 2 mol / L, and the molar ratio of nickel ion, manganese ion and cobalt ion is 0.9:0.055:0.045;

[0100] The spray pyrolysis includes sequential atomization and pyrolysis; the atomizing gas flow rate during atomization is 10 L / min, the atomizing gas is composed of nitrogen and air in a volume ratio of 4.5:1, and the atomization angle is 30°; the temperature of the upper section of the spray pyrolysis furnace during the spray pyrolysis is 300° C., and the temperature of the lower section of the spray pyrolysis furnace is 900° C.; the total residence time of the precursor solution in the spray pyrolysis furnace during the spray pyrolysis is 10 s;

[0101] (2) mixing the precursor obtained in step (1) with a lithium source, heating the mixture to 820° C. at a rate of 3° C. / min in an air atmosphere, maintaining the temperature for 13 h, and then cooling the mixture naturally to obtain a single crystal ultrahigh nickel cathode material;

[0102] (3) The single crystal ultrahigh nickel positive electrode material and Li2ZrO3 were mixed by ball milling with a ball-to-material ratio of 7:1, a rotation speed of 400 rpm and a time of 1.5 h. The obtained mixture was heated to 620°C at a rate of 3°C / min in an air atmosphere and then kept warm for 6 h to obtain the positive electrode material.

[0103] Example 4

[0104] This embodiment provides a positive electrode material (D50 particle size is 0.5 μm) comprising a Li2ZrO3 coating layer, wherein the positive electrode material comprises a single crystal ultra-high nickel positive electrode material (chemical formula is Ni 0.85 Co 0.075 Mn 0.075 O2), and a Li2ZrO3 coating layer coated on the outside of the single crystal ultra-high nickel positive electrode material;

[0105] Based on the mass of the positive electrode material, the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.32wt%;

[0106] The preparation method of the positive electrode material is:

[0107] (1) spray pyrolysis of a precursor solution containing nickel ions, manganese ions, and cobalt ions to obtain a precursor;

[0108] The total metal ion concentration in the precursor solution is 0.5 mol / L, and the molar ratio of nickel ion, manganese ion and cobalt ion is (0.85-0.95):(0.035-0.075):(0.015-0.075);

[0109] The spray pyrolysis includes sequential atomization and pyrolysis; the atomizing gas flow rate during atomization is 15 L / min, the atomizing gas is composed of nitrogen and air in a volume ratio of 3:1, and the atomization angle is 60°; the temperature of the upper section of the spray pyrolysis furnace during the spray pyrolysis is 200° C., and the temperature of the lower section of the spray pyrolysis furnace is 800° C.; the total residence time of the precursor solution in the spray pyrolysis furnace during the spray pyrolysis is 12 s;

[0110] (2) mixing the precursor obtained in step (1) with a lithium source, heating the mixture to 800° C. at a rate of 1° C. / min in an air atmosphere, maintaining the temperature for 14 h, and then cooling the mixture naturally to obtain a single crystal ultrahigh nickel cathode material;

[0111] (3) The single crystal ultrahigh nickel positive electrode material and Li2ZrO3 were mixed by ball milling with a ball-to-material ratio of 15:1, a rotation speed of 100 rpm and a time of 3 hours. The obtained mixture was heated to 700°C at a rate of 10°C / min in an air atmosphere and then kept warm for 3 hours to obtain the positive electrode material.

[0112] Example 5

[0113] This embodiment provides a positive electrode material (D50 particle size is 1.0 μm) comprising a Li2ZrO3 coating layer, wherein the positive electrode material comprises a single crystal ultra-high nickel positive electrode material (chemical formula is Ni 0.95 Co 0.035 Mn 0.015 O2), and a Li2ZrO3 coating layer coated on the outside of the single crystal ultra-high nickel positive electrode material;

[0114] Based on the mass of the positive electrode material, the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.08wt%;

[0115] The preparation method of the positive electrode material is:

[0116] (1) spray pyrolysis of a precursor solution containing nickel ions, manganese ions, and cobalt ions to obtain a precursor;

[0117] The total metal ion concentration in the precursor solution is 2.5 mol / L, and the molar ratio of nickel ion, manganese ion and cobalt ion is (0.85-0.95):(0.035-0.075):(0.015-0.075);

[0118] The spray pyrolysis includes sequential atomization and pyrolysis; the atomizing gas flow rate during atomization is 8 L / min, the atomizing gas is composed of nitrogen and air in a volume ratio of 5:1, and the atomization angle is 20°; the temperature of the upper section of the spray pyrolysis furnace during the spray pyrolysis is 400° C., and the temperature of the lower section of the spray pyrolysis furnace is 1200° C.; the total residence time of the precursor solution in the spray pyrolysis furnace during the spray pyrolysis is 5 s;

[0119] (2) mixing the precursor obtained in step (1) with a lithium source, heating the mixture to 900° C. at a rate of 10° C. / min in an air atmosphere, holding the temperature for 10 h, and then cooling the mixture naturally to obtain a single crystal ultrahigh nickel cathode material;

[0120] (3) The single crystal ultrahigh nickel positive electrode material and Li2ZrO3 were mixed by ball milling with a ball-to-material ratio of 5:1, a rotation speed of 500 rpm and a time of 1 hour. The obtained mixture was heated to 600°C at a rate of 1°C / min in an air atmosphere and then kept warm for 7 hours to obtain the positive electrode material.

[0121] Example 6

[0122] This embodiment provides a positive electrode material including a Li2ZrO3 coating layer, which is the same as that of Example 1 except that the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.04 wt %, based on the mass of the positive electrode material.

[0123] Example 7

[0124] This embodiment provides a positive electrode material including a Li2ZrO3 coating layer, which is the same as that of Example 1 except that the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.4 wt %, based on the mass of the positive electrode material.

[0125] Example 8

[0126] This embodiment provides a positive electrode material including a Li2ZrO3 coating layer, which is the same as that of Example 1 except that the D50 particle size of the positive electrode material is 0.3 μm.

[0127] Example 9

[0128] This embodiment provides a positive electrode material including a Li2ZrO3 coating layer, which is the same as that of Example 1 except that the D50 particle size of the positive electrode material is 1.5 μm.

[0129] Example 10

[0130] This embodiment provides a positive electrode material comprising a Li2ZrO3 coating layer, except that in step (1) of the preparation method of the positive electrode material, the atomizing gas flow rate during atomization in the spray pyrolysis is 10m3 / h, the rest are the same as in Example 1.

[0131] Example 11

[0132] This embodiment provides a positive electrode material comprising a Li2ZrO2 coating layer, wherein in step (1) of the preparation method of the positive electrode material, the atomizing gas flow rate is 40 m / s except that during the atomization in the spray pyrolysis, 3 / h, the rest are the same as in Example 1.

[0133] Example 12

[0134] This embodiment provides a positive electrode material comprising a Li2ZrO3 coating layer. Except for step (1) of the method for preparing the positive electrode material, the temperature of the lower section of the spray pyrolysis calcining furnace in the spray pyrolysis is 600°C, and the rest is the same as in Example 1.

[0135] Example 13

[0136] This embodiment provides a positive electrode material comprising a Li2ZrO3 coating layer. Except for step (1) of the method for preparing the positive electrode material, the temperature of the lower section of the spray pyrolysis furnace in the spray pyrolysis is 1400°C, and the rest is the same as in Example 1.

[0137] Example 14

[0138] This embodiment provides a positive electrode material comprising a Li2ZrO3 coating layer. Except for step (3) of the positive electrode material preparation method, which involves heating to 500°C and then maintaining the temperature, the rest is the same as in Example 1.

[0139] Example 15

[0140] This embodiment provides a positive electrode material comprising a Li2ZrO3 coating layer. Except for step (3) of the positive electrode material preparation method, which involves heating to 800°C and then maintaining the temperature, the rest is the same as in Example 1.

[0141] Comparative Example 1

[0142] This comparative example provides a positive electrode material including a Li2ZrO3 coating layer, which is the same as Example 1 except that the Li2ZrO3 coating layer is replaced by a Li3BO3 coating layer.

[0143] Comparative Example 2

[0144] This comparative example provides a positive electrode material comprising a Li2ZrO3 coating layer, which is the same as Example 1 except that the Li2ZrO3 coating layer on the outside of the single crystal ultra-high nickel positive electrode material is omitted.

[0145] A lithium-ion battery was prepared using the positive electrode materials provided in the above embodiments and comparative examples: the obtained positive electrode material, conductive carbon black SP and polyvinylidene fluoride PVDF were mixed in a mass ratio of 90:5:5, N-methylpyrrolidone was used as the solvent, and the mixture was stirred into a slurry. The obtained slurry was evenly coated on an aluminum foil with a scraper with a coating gap of 100 μm; after coating, it was first blown dry, then rolled and cut into circular electrode sheets, and then vacuum dried at 120°C and weighed to obtain a button half-cell positive electrode sheet; a metal lithium sheet was selected as the negative electrode, a PP microporous membrane was selected as the diaphragm, and a lithium battery basic electrolyte was selected as the electrolyte. The positive electrode sheet, the metal lithium sheet, the diaphragm and the electrolyte were assembled to obtain a button battery.

[0146] The obtained button battery was charged and discharged at 0.1C / 0.1C, and the charge and discharge test was carried out in the voltage window of 2.8-4.3V. The 0.1C rate performance of the button battery and the capacity retention rate after 100 cycles at 1C are shown in Table 1.

[0147] Table 1

[0148] 0.1C rate (mAh / g) Capacity retention rate (%) Example 1 212 88 Example 2 209 89 Example 3 213 88 Example 4 210 87 Example 5 205 85 Example 6 198 79 Example 7 195 80 Example 8 190 78 Example 9 190 75 Example 10 180 73 Example 11 191 78 Example 12 195 79 Example 13 199 80 Example 14 193 78 Example 15 189 78 Comparative Example 1 190 79 Comparative Example 2 179 68

[0149] From Table 1, we can get:

[0150] (1) The battery prepared using the positive electrode material comprising the Li2ZrO3 coating layer provided in Examples 1 to 5 has high rate performance and excellent cycle stability;

[0151] (2) By comparing Example 1 with Examples 6 and 7, it can be seen that in the present invention, based on the mass of the positive electrode material as a percentage, the mass fraction of the Li2ZrO3 coating layer in the positive electrode material will affect the performance of the positive electrode material and the battery; in the present invention, by limiting the coating layer containing Li2ZrO3 to be composed of Li2ZrO3, and the mass fraction of the Li2ZrO3 coating layer in the positive electrode material to 0.08-0.32wt%, the positive electrode material can accelerate lithium ion migration, reduce transition metal dissolution and SEI film degradation, thereby making the positive electrode material have higher interface stability, and thus making the battery prepared with the positive electrode material have better cycle stability;

[0152] (3) By comparing Example 1 with Examples 8 and 9, it can be seen that the D50 particle size of the positive electrode material in the present invention affects the performance of the positive electrode material and the battery; in the present invention, by limiting the D50 particle size of the positive electrode material to 0.5-1.0 μm, the positive electrode material has a larger grain size and therefore has a lower specific surface area, thereby effectively further suppressing the interfacial side reactions of the positive electrode material and improving the cycle stability of the battery;

[0153] (4) By comparing Example 1 with Examples 10 and 11, it can be seen that in the preparation method of the positive electrode material of the present invention, the atomizing gas flow rate during atomization in the spray pyrolysis will affect the performance of the positive electrode material and the battery; the atomizing gas flow rate during atomization in the spray pyrolysis is limited to 20 to 30 m / s. 3 / h, by optimizing the droplet size to make the precursor particles uniform, reducing the formation of grain boundaries after calcination and improving the lithium ion diffusion efficiency; at the same time, the flow rate matches the pyrolysis residence time to ensure the uniform distribution of transition metals, promote isotropic growth of single crystals, and reduce the lattice defect density; in addition, the single crystal ultra-high nickel cathode material with uniform distribution of transition metals is conducive to the formation of a dense coating of Li2ZrO3 on the single crystal surface, reducing the interfacial impedance and inhibiting the dissolution of transition metals, synergistically improving the rate performance and cycle stability;

[0154] (5) By comparing Example 1 with Examples 12 and 13, it can be seen that in the present invention, in the method for preparing the positive electrode material, the temperature of the lower section of the spray pyrolysis calciner in the spray pyrolysis will affect the performance of the positive electrode material and the battery; when the temperature of the lower section of the spray pyrolysis calciner is controlled to be 800-1200°C in the spray pyrolysis, it is beneficial to improve the performance of the positive electrode material. This is because the temperature of 800-1200°C can optimize the material structure stability and the lithium ion diffusion path, thereby improving the rate performance and cycle stability of the battery prepared with the positive electrode material;

[0155] (6) By comparing Example 1 with Examples 14 and 15, it can be seen that in the method for preparing the positive electrode material of the present invention, the temperature of the heat treatment in an oxygen-containing atmosphere after the single crystal ultra-high nickel positive electrode material is mixed with Li2ZrO3 will affect the performance of the positive electrode material and the battery; when the temperature of the second insulation in the heat treatment is 600-700°C, the grain size (a positive electrode material with a larger D50 particle size) and the interface stability are simultaneously optimized, and the electrochemical performance of the prepared positive electrode material is significantly improved;

[0156] (7) By comparing Example 1 with Comparative Examples 1 to 2, it can be seen that the positive electrode material provided by the present invention includes a single crystal ultra-high nickel positive electrode material and a Li2ZrO3 coating layer. The single crystal ultra-high nickel material has no grain boundaries, which reduces the path for nickel ions to migrate to the lithium layer, and Li 22 The ZrO3 coating prevents nickel dissolution and diffusion to lithium sites through surface defect passivation and oxygen vacancy suppression. In addition, the Li2ZrO3 coating acts as a chemical barrier, reducing surface reconstruction caused by electrolyte corrosion. At the same time, the Li2ZrO3 in the Li2ZrO3 coating acts as a fast ion conductor, promoting uniform lithium ion deintercalation and weakening the driving force for nickel migration, thereby significantly alleviating lithium / nickel mixing.

[0157] The cathode material provided by the present invention includes a single-crystal ultra-high nickel cathode material and a Li2ZrO3 coating layer. The Li2ZrO3 coating layer physically isolates the single-crystal ultra-high nickel cathode material from direct contact with the electrolyte, thereby reducing the dissolution of transition metals in the single-crystal ultra-high nickel cathode material and the oxidative decomposition of the electrolyte. In addition, compared with polycrystalline materials, the large grains of the single-crystal ultra-high nickel cathode material significantly reduce the specific surface area of the cathode material, reduce the exposure of active sites, and cooperate with the coating layer to reduce interfacial side reactions.

[0158] The cathode material provided by the present invention includes a single-crystal ultra-high nickel cathode material and a Li2ZrO3 coating layer. The single-crystal ultra-high nickel cathode material has no grain boundaries, and its complete lattice can evenly disperse the stress during the lithium insertion and extraction process. In addition, the Li2ZrO3 coating layer limits the expansion and contraction of the single-crystal ultra-high nickel cathode material through physical constraints. In addition, the Li2ZrO3 in the Li2ZrO3 coating layer promotes the uniform insertion and extraction of lithium ions, avoiding severe lattice deformation caused by local lithium concentration gradients.

[0159] In summary, the positive electrode material provided by the present invention is composed of a single crystal ultra-high nickel positive electrode material and a Li2ZrO3 coating layer; the single crystal structure has no grain boundaries, which blocks the migration path of nickel ions to the lithium layer, while the Li2ZrO3 coating layer blocks the dissolution and diffusion of nickel, promotes the uniform deintercalation of lithium ions, and alleviates lithium / nickel mixing; at the same time, the coating layer physically isolates the direct contact between the electrolyte and the single crystal ultra-high nickel positive electrode material, reducing the dissolution of transition metals and the oxidation and decomposition side reactions of the electrolyte; the large grain characteristics of the single crystal material reduce the specific surface area, and the coating layer cooperates to reduce the exposure of active sites, further inhibiting the interface side reactions; in addition, the complete lattice of the single crystal can evenly disperse the stress during the lithium deintercalation process, and the coating layer limits the expansion / contraction freedom of the material through mechanical constraints, thereby synergistically inhibiting lattice distortion and volume shrinkage. Therefore, the battery prepared with the positive electrode material provided by the present invention has excellent cycle stability.

[0160] 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 thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention.

Claims

1. A positive electrode material comprising a Li2ZrO3 coating layer, characterized in that: The positive electrode material includes a single crystal ultra-high nickel positive electrode material and a Li2ZrO3 coating layer coated on the outside of the single crystal ultra-high nickel positive electrode material.

2. The positive electrode material according to claim 1, characterized in that Based on the mass of the positive electrode material as 100%, the mass fraction of the Li2ZrO3 coating layer in the positive electrode material is 0.08-0.32wt%.

3. The positive electrode material according to claim 1, characterized in that The chemical formula of the single crystal ultra-high nickel positive electrode material is Ni x Co y Mn z O2; wherein, x is 0.85 to 0.95, y is 0.035 to 0.075, z is 0.015 to 0.075, and x+y+z=1.

4. The positive electrode material according to claim 1, characterized in that The D50 particle size of the positive electrode material is 0.5 to 1.0 μm.

5. A method for preparing the positive electrode material according to any one of claims 1 to 4, characterized in that: The preparation method comprises: The single crystal ultra-high nickel cathode material is mixed with Li2ZrO3 and then heat treated in an oxygen-containing atmosphere to obtain a cathode material.

6. The preparation method according to claim 5, characterized in that The method for preparing the single crystal ultra-high nickel positive electrode material comprises: A precursor solution containing nickel ions, manganese ions, and cobalt ions is spray-pyrolyzed to obtain a precursor; the obtained precursor is then mixed with a lithium source and calcined in an oxygen-containing atmosphere to obtain a single-crystal ultra-high nickel cathode material; Preferably, the spray pyrolysis comprises atomization and pyrolysis performed sequentially; Preferably, the atomizing gas flow rate during atomization in the spray pyrolysis is 20 to 30 m / s. 3 / h; Preferably, the atomizing gas during atomization in the spray pyrolysis comprises nitrogen and air in a volume ratio of (3-5):1; Preferably, the atomization angle during atomization in the spray pyrolysis is 20 to 60°; Preferably, the temperature of the upper section of the spray pyrolysis roasting furnace in the spray pyrolysis is 200-400°C, and the temperature of the lower section of the spray pyrolysis roasting furnace is 800-1200°C; Preferably, the total residence time of the precursor solution in the spray pyrolysis furnace during the spray pyrolysis is 5 to 12 seconds; Preferably, the calcination comprises a first heating and a first heat preservation performed sequentially; Preferably, the first heating rate is 1-10°C / min; Preferably, the temperature of the first insulation is 800-900° C., and the time is 10-14 hours.

7. The preparation method according to claim 5, characterized in that The heat treatment includes a second temperature increase and a second temperature holding performed sequentially; Preferably, the second heating rate is 1-10°C / min; Preferably, the second insulation temperature is 600-700° C., and the time is 3-7 hours.

8. The preparation method according to claim 5, characterized in that The preparation method comprises: (1) spray pyrolysis of a precursor solution containing nickel ions, manganese ions, and cobalt ions to obtain a precursor; The total metal ion concentration in the precursor solution is 0.5-2.5 mol / L, and the molar ratio of nickel ion, manganese ion and cobalt ion is (0.85-0.95):(0.035-0.075):(0.015-0.075); The spray pyrolysis includes atomization and pyrolysis performed in sequence; the atomization gas flow rate during atomization is 20 to 30 m 3 / h, the atomizing gas is composed of nitrogen and air in a volume ratio of (3-5):1, and the atomization angle is 20-60°; the temperature of the upper section of the spray pyrolysis furnace in the spray pyrolysis is 200-400°C, and the temperature of the lower section of the spray pyrolysis furnace is 800-1200°C; the total residence time of the precursor solution in the spray pyrolysis furnace in the spray pyrolysis is 5-12s; (2) mixing the precursor obtained in step (1) with a lithium source, heating the mixture to 800-900° C. at a rate of 1-10° C. / min in an air atmosphere, maintaining the temperature for 10-14 hours, and then cooling the mixture naturally to obtain a single crystal ultrahigh nickel cathode material; (3) The single crystal ultrahigh nickel positive electrode material and Li2ZrO3 are mixed by ball milling with a ball-to-material ratio of (5-15):1, a rotation speed of 100-500 rpm and a time of 1-3 hours, and the obtained mixture is heated to 600-700°C at a rate of 1-10°C / min in an air atmosphere and then kept warm for 3-7 hours to obtain the positive electrode material.

9. A positive electrode plate, characterized in that: The positive electrode sheet comprises the positive electrode material according to any one of claims 1 to 4.

10. A battery, characterized in that: The battery comprises the positive electrode sheet according to claim 9.