Modified high-nickel ternary positive electrode material, preparation method and application thereof

Abstract

The application discloses a modified high-nickel ternary positive electrode material, and relates to the technical field of lithium ion batteries. x Co y Mn 1‑x‑y (OH) z , wherein 0.7<=x<=0.95, 0.02<=y<=0.25, and 0<=z<=4; the modified high-nickel ternary positive electrode material comprises a main body and modified elements; the main body is made of a precursor, and the general formula of the precursor is LiNi The application further provides a preparation method of the modified high-nickel ternary positive electrode material, application of the modified high-nickel ternary positive electrode material in preparation of lithium ion batteries, a lithium ion battery containing the modified high-nickel ternary positive electrode material and a preparation method of the lithium ion battery. The modified high-nickel ternary positive electrode material and the lithium ion battery have excellent performances in high specific capacity and cycle life, and are suitable for application occasions with high requirements for high energy density and high safety in power batteries and energy storage systems.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of preparation of lithium ion battery cathode materials, and particularly relates to a modified high-nickel ternary cathode material and a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of global electric vehicles and energy storage markets, the transformation trend of energy structure is increasingly obvious, and the demand for lithium ion batteries with high energy density and high safety is also increasing. Under this background, high-nickel ternary cathode materials have become the research focus of the next generation of power batteries and energy storage systems due to their high specific capacity and significant cost advantage.

[0003] However, at present, such materials still face a series of key problems to be solved in commercial application. First, the lattice structure instability caused by high nickel content easily leads to cation mixing, which weakens the cycle performance and energy density of the material; second, the volume change caused by electrochemical cycling often forms micro-cracks inside or on the surface of the material particles, accelerating the degradation of active materials; third, the side reaction between the material surface and the electrolyte produces an unstable interface layer, which significantly affects the rate performance and cycle life of the battery; in addition, under high voltage conditions, high-nickel ternary materials are prone to phase transition or lattice collapse, further aggravating structural degradation. The above problems not only restrict the sustainable development of high-nickel ternary cathode materials in the field of power batteries and energy storage systems, but also affect the expansion of the overall application scale. Therefore, it is urgent to enhance the structural stability and electrochemical performance of high-nickel ternary cathode materials through element doping, surface modification, coating and preparation process optimization and other means, so as to promote their large-scale, long-life, safe and reliable application in the new energy vehicle and energy storage industries.

[0004] Although the prior art has proposed various improvement ideas for the above problems, there are still some deficiencies. For example, CN117981115A discloses a modified high-nickel ternary positive electrode material, which is synthesized by alkali metal / transition metal doping and Li2SO4, cobalt, Al / Ti three layers from the precursor without washing, and then doped and coated by three times of sintering, the performance is improved, but the process is complex, the cost of cobalt is high, the high temperature stability of Li2SO4 is doubtful, and the reliability of large-scale application has not been verified. Patent CN114436347B discloses a high-nickel ternary positive electrode material, which is prepared by mixing the precursor / lithium source at high speed, introducing a grain boundary enrichment additive (such as B2O3, WO3) at low speed, and gradient sintering process, which strengthens the particle crack resistance and improves the cycle and gas production performance. However, the process steps are complicated, the dispersion control of the additive is difficult, and the cost may be increased. Patent CN118183880A discloses a high-nickel ternary positive electrode material preparation method, which is mixed and sintered by doping elements (Zr, Al, etc.) and lithium source, then coated with low-temperature nano-cobalt boride solution after crushing and secondary sintering, which avoids water washing and reduces residual alkali, but the process is complex, the cost of nano-materials is high, and the high-temperature sintering energy consumption is large, which is difficult to realize large-scale production in actual production.

[0005] In order to overcome the above technical limitations and meet the growing demand for high-nickel ternary materials, in recent years, the academic and industrial circles have carried out in-depth research on the structure stability, cycle life and thermal safety of high-nickel positive electrode, and have put forward a series of modification strategies with high application potential, mainly including the following directions:

[0006] (1) Element doping and gradient distribution: In the Ni, Co, Mn ternary system, elements such as Al, Mg, Ti, Zr, W, B, F are introduced or element gradient distribution is designed, which can effectively inhibit the crystal structure phase transition and cation mixing on the premise of not significantly reducing the specific capacity of the material, and improve the cycle stability and thermal safety of the material.

[0007] (2) Surface coating and interface engineering: A dense and stable coating layer (such as metal oxide, fluoride, phosphate or composite coating) is formed on the surface of the positive electrode by physical or chemical methods, which can greatly reduce the side reaction between the positive electrode and the electrolyte and weaken the interface corrosion of high-nickel materials at high voltage. Some studies also attempt to build a core-shell structure or a single crystal microstructure to improve the tolerance to volume change and reduce crack generation.

[0008] (3) Preparation process optimization: By precisely controlling the pH value, type of precipitant, stirring speed, reaction temperature and other key parameters in the co-precipitation process, combined with gradient temperature control and atmosphere adjustment of the subsequent sintering and annealing process, high-nickel precursors and positive electrode materials with good dispersion, uniform particles and excellent structural integrity can be prepared. At the same time, shortening the complex intermediate operation steps helps to reduce production cost and improve product consistency.

[0009] (4) Electrolyte and battery system collaborative design: High-voltage application of high-nickel ternary cathode requires further enhancement of electrolyte system in oxidation stability, interface film formation and conductivity. Suitable additives or new electrolyte systems (such as borate, ionic liquid, monomer functional additive, etc.) and cathode surface modification synergistic cooperation can significantly improve the cycle life and safety reliability of the material.

[0010] On the basis of the above research and patent results, it is still urgent to optimize from the aspects of material doping, surface modification and process integration, etc. to realize the comprehensive improvement of thermal stability, cycle life, specific capacity and safety. SUMMARY

[0011] One object of the present application is to provide a high-nickel ternary cathode material with good thermal stability, cycle life, specific capacity and safety for solving the above technical problems.

[0012] Another object of the present application is to provide a preparation method of the high-nickel ternary cathode material.

[0013] Still another object of the present application is to provide an application of the high-nickel ternary cathode material.

[0014] Still another object of the present application is to provide a lithium ion battery.

[0015] Still another object of the present application is to provide a preparation method of the lithium ion battery.

[0016] In order to achieve the above objects of the present application, the present application provides the following technical solutions.

[0017] In a first aspect, the present application provides a modified high-nickel ternary cathode material, which comprises a main body and a modified element. The main body is made of a precursor, and the general formula of the precursor is LiNi x Co y Mn 1-x-y (OH) zwherein 0.7≤x≤0.95, 0.02≤y≤0.25, 0≤z≤4; more preferably, 0.75≤x≤0.92, 0.05≤y≤0.18, 1≤z≤3. More preferably, 0.78≤x≤0.85, 0.1≤y≤0.12, z=2. The modifying elements include first type modifying elements and second type modifying elements, wherein the first type modifying elements are one or more of W (tungsten), Nb (niobium), Ta (tantalum), Re (rhenium), Mo (molybdenum), Hf (hafnium), Zr (zirconium), and the second type modifying elements are one or more of Te (tellurium), As (arsenic), Ge (germanium), Sb (antimony), Se (selenium), the first type modifying elements and the second type modifying elements are added in the form of their compounds, the total amount of the first type modifying element compounds and the second type modifying element compounds added is 0.2-4wt% of the precursor, and the mass ratio of the first type modifying element compounds to the second type modifying element compounds is 1:10 to 10:1.

[0018] Preferably, the first type modifying element compounds are oxides, salts or heteropoly acids containing the first type modifying elements. Taking W (tungsten) as an example, the specific compound forms of the first type modifying elements include but are not limited to tungsten trioxide, tungsten dioxide, sodium tungstate, ammonium tungstate, ammonium paratungstate, tungstic acid, etc. The available specific compound forms of other elements Nb (niobium), Ta (tantalum), Re (rhenium), Mo (molybdenum), Hf (hafnium), Zr (zirconium) include but are not limited to niobium pentoxide, ammonium niobate, sodium tantalate, tantalum pentoxide, sodium perrhenate, rhenium heptoxide, ammonium molybdate, molybdenum trioxide, hafnium dioxide, zirconic acid, zirconium dioxide, ammonium zirconate, etc.

[0019] Preferably, the second type modifying element compounds are oxides, salts or heteropoly acids containing the second type modifying elements. Taking Te (tellurium) as an example, the specific compound forms of the second type modifying elements include but are not limited to telluric acid, tellurium dioxide, tellurate, tellurous acid, tellurous acid salt, etc. The available specific compound forms of other elements As (arsenic), Ge (germanium), Sb (antimony), Se (selenium) include but are not limited to ammonium arsenate, sodium arsenate, germanium dioxide, sodium germanate, ammonium germanate, antimony trioxide, ammonium antimonate, selenium dioxide, selenic acid, sodium selenate, etc.

[0020] Preferably, the general formula of the host matrix is LiNi x Co y Mn 1-x-y O2, wherein 0.7≤x≤0.95, 0.02≤y≤0.25. More preferably, 0.75≤x≤0.92, 0.05≤y≤0.18. More preferably, 0.78≤x≤0.85, 0.1≤y≤0.12.

[0021] Preferably, the total amount of the first type of modified element compound and the second type of modified element compound is 0.5-3.5wt% of the precursor. More preferably, the total amount of the first type of modified element compound and the second type of modified element compound is 1.0-3wt% of the precursor.

[0022] Preferably, the mass ratio of the first type of modified element compound to the second type of modified element compound is 1:10 to 10:1. More preferably, the mass ratio of the first type of modified element compound to the second type of modified element compound is 1:5 to 5:1, and particularly preferably 1:2 to 2:1.

[0023] In a second aspect, the present application provides a preparation method of the modified high-nickel ternary positive electrode material, which comprises:

[0024] (1) Preparation of a precursor: a precursor with a general formula of Ni x Co y Mn 1-x-y (OH) z is prepared, wherein 0.7≤x≤0.95, 0.02≤y≤0.25, 0≤z≤4, and 0-100% of the first type of modified element is added during the process;

[0025] (2) Ball milling: the total number of moles of metal elements in the precursor powder is mixed with lithium elements in the lithium source at a molar ratio of 1:1 to 1:1.15, and the remaining first type of modified element and all the second type of modified element are added, followed by ball milling, drying, to obtain a modified mixed powder;

[0026] (3) Calcination: the dried material is calcined, and the modified high-nickel ternary positive electrode material is prepared.

[0027] Preferably, the first type of modified element compound is added for modification in the preparation of the precursor stage, and the second type of modified element compound is added for modification in the ball milling stage.

[0028] Preferably, no modification is performed in the preparation of the precursor stage, and the first type of modified element compound and the second type of modified element compound are added for modification in the ball milling stage.

[0029] Preferably, part of the first type of modified element compound is added for modification in the preparation of the precursor stage, and the remaining part of the first type of modified element compound and the second type of modified element compound are added for modification in the ball milling stage.

[0030] The first type of modification element mainly plays a role in inhibiting cation mixing and increasing the stability of bulk structure by solid solution or substitution in the material lattice, or part of the modification element is in the form of solid solution or substitution in the material lattice, and the other part is coated on the surface of the material. The second type of modification element is preferably distributed on the surface or local interface of the material, and forms a dense covering layer during calcination to weaken the side reaction and improve the thermal stability and electrical conductivity. Through the dual modification of the first type of modification element and the second type of modification element, the internal and external structures of the material are multi-strengthened.

[0031] Preferably, the preparation method of the precursor includes but is not limited to coprecipitation, sol-gel method, hydrothermal method, and spray pyrolysis.

[0032] Preferably, the preparation method of the precursor is a coprecipitation method. The nickel source, the cobalt source and the manganese source are weighed according to the ratio, dissolved in deionized water, and the first type of modification element is added as needed. Hydroxide (sodium hydroxide, potassium hydroxide, etc.) is used as a precipitant, and ammonia solution is used as a complexing agent. The coprecipitation temperature is 30-100°C, and the solution pH is 8-14. The metal ions are uniformly precipitated to form a uniform precipitate. The precipitate is then washed, filtered and dried (70-130°C, 1-12 hours) to obtain a precursor powder. Preferably, the coprecipitation temperature is 40-90°C, and the pH value is 9-13; more preferably, the coprecipitation temperature is 50-80°C, and the pH is 10-12. If the first type of modification element needs to be partially / fully added at the precursor stage, the corresponding salt of the first type of modification element can be dissolved in the metal salt solution for homogenous precipitation. The salt corresponding to the first type of modification element includes but is not limited to nitrate, chloride, sulfate or acetate, etc.

[0033] Preferably, the preparation method of the precursor is a sol-gel method. The nickel source, the cobalt source and the manganese source are weighed according to the ratio, and the first type of modification element is added as needed. The complexing agent is mixed to form a uniform sol. The obtained sol is evaporated by heating to form a gel. The gel is sintered at 500-800°C to obtain a precursor. The sintering temperature is 400-900°C, and the sintering time is 1-12 hours. Preferably, the sintering temperature is 500-800°C, and the sintering time is 1-10 hours. More preferably, the sintering temperature is 550-750°C, and the sintering time is 2-8 hours. If the first type of modification element needs to be introduced at the same time, the salt of the first type of modification element can be added during the preparation of the sol to ensure the dispersion degree of the element.

[0034] Preferably, the preparation method of the precursor is a hydrothermal method. The nickel source, cobalt source and manganese source are weighed according to the proportion, dissolved in deionized water, the first type of modified elements are added as needed, the pH of the solution is adjusted to 5-8, the solution is placed in a high-pressure reaction kettle for reaction, the hydrothermal temperature is 130-260°C, and the reaction time is 6-72 hours. After the reaction is completed, cooling, filtering and drying are performed to obtain the high-nickel ternary precursor. Preferably, the hydrothermal temperature is 180-200°C, and the reaction time is 12-48 hours. More preferably, the hydrothermal temperature is 185-195°C, and the reaction time is 16-36 hours.

[0035] Preferably, the preparation method of the precursor is a spray pyrolysis method. The nickel source, cobalt source and manganese source are weighed according to the proportion, dissolved in deionized water to form a uniform solution, and the first type of modified elements are added as needed. The solution is atomized by a spraying device, and a high-nickel ternary battery precursor is directly generated by pyrolysis reaction at 700-900°C. Preferably, the pyrolysis temperature is 750-850°C.

[0036] The precursor prepared by the above method has the characteristics of regular crystal morphology, uniform particle distribution and good dispersibility, and is suitable for the preparation of high-performance lithium ion battery positive electrode materials. The particle size D50 of the prepared precursor powder can be 1-20μm. Preferably, D50 is 3-15μm. More preferably, D50 is 5-10μm. The regular particle morphology and good dispersibility of the precursor powder ensure subsequent ball milling and calcination.

[0037] Preferably, the lithium source is at least one of lithium carbonate or lithium hydroxide.

[0038] Preferably, the ball milling speed is 300-700r / min, more preferably 400-600r / min. The ball milling time is preferably 2-15 hours, more preferably 4-12 hours, and more preferably 5-8 hours. The ball-to-material ratio is preferably 5:1-30:1, more preferably 10:1-20:1, and more preferably 12:1-18:1. The drying temperature is preferably 60-120°C, and the drying time is preferably 1-10 hours.

[0039] Preferably, the calcination is a staged calcination process, wherein the first stage is precalcination at 450-550°C for 5-10 hours, more preferably 470-530°C for 6-8 hours; the second stage is main calcination at 750-850°C for 10-20 hours, the heating rate is 2-10°C / min, and the calcination atmosphere is oxygen or oxygen-rich atmosphere. More preferably, the second stage is at 780-820°C for 12-18 hours, and the heating rate is 3-6°C / min.

[0040] Through the segmental calcination process, the first type of modified element is solid-solved or replaced in the host lattice, and the second type of modified element forms a stable covering layer on the surface or in the local interface region, effectively enhancing the cycle life and safety performance of the high-nickel positive electrode material at a high voltage of 4.0-4.6V.

[0041] In a third aspect, the application further provides application of the modified high-nickel ternary positive electrode material in preparation of a lithium ion battery.

[0042] In a fourth aspect, the application further provides a lithium ion battery containing the modified positive electrode material.

[0043] In a fifth aspect, the application further provides a preparation method of the lithium ion battery, which comprises the following steps:

[0044] (1) preparing a battery positive electrode sheet: the modified high-nickel ternary positive electrode material, a binder and a conductive agent are prepared into a battery positive electrode sheet through beating-up, coating, rolling and slicing processes;

[0045] (2) assembling a battery: the battery positive electrode sheet, an electrolyte, a separator and a negative electrode sheet are sequentially assembled into the lithium ion battery.

[0046] Preferably, the mass ratio of the modified high-nickel ternary positive electrode material, the binder and the conductive agent is 6:0.5:0.5 to 9:2:2, more preferably 8:1:1 or 8.5:0.5:1.

[0047] Preferably, the binder includes but is not limited to PVDF, CMC and SBR, and the conductive agent includes but is not limited to carbon black and conductive graphite.

[0048] Preferably, the negative electrode sheet includes but is not limited to metallic lithium or graphite.

[0049] In view of the deficiencies of the high-nickel ternary positive electrode material in cycle stability, thermal stability and rate in the prior art, the application provides a method for synergistically modifying the high-nickel ternary positive electrode material by introducing two or more elements. The material obtained by the method has uniform particle size, stable lattice structure, and can maintain excellent cycle life and safety performance under high energy density conditions, meeting the demand for high specific capacity and long life of power batteries and energy storage systems. The innovative high-nickel ternary positive electrode material modification method proposed in the application significantly enhances the cycle life and safety performance of the material under high energy density conditions through targeted regulation of the intrinsic structure of the material and stabilization treatment of the surface layer interface, solves the problem that the prior art cannot balance large-scale production and product consistency, and lays an important foundation for the wide application of high-nickel positive electrode materials in new energy vehicle power batteries and large-scale energy storage systems.

[0050] The present application proposes a multi-stage and multi-element modification strategy for the preparation and performance enhancement of high-nickel ternary positive materials, and has the following significant advantages:

[0051] (1) Multi-mode modification element introduction, adapting to various preparation processes

[0052] The present application adds the first type of modification elements (W, Nb, Ta, Re, Mo, Hf, Zr, etc.) and the second type of modification elements (Te, As, Ge, Sb, Se, etc.) in two stages of precursor preparation and ball milling, forming three process modes. Whether using co-precipitation, sol-gel, hydrothermal or spray pyrolysis, or using different ball milling and calcination equipment, modification can be flexibly realized, meeting the needs of various production environments.

[0053] (2) Internal and external structure synergistic enhancement, improving cycle and thermal stability

[0054] The first type of modification elements are solid-soluted or replaced in the material lattice after high-temperature calcination, significantly inhibiting cation mixing and micro-crack generation; the second type of modification elements are distributed on the material surface, forming a dense covering layer, reducing electrolyte corrosion and interface side reactions. The internal and external synergistic effect enables high-nickel materials to maintain stable structure and excellent cycle life in high-voltage environment. Test results show that the modified high-nickel ternary positive material of the present application can be stably operated in the working voltage range of 2.5-4.5V, and the capacity attenuation is not more than 10-25% after 500 cycles in the range of 2.8-4.3V.

[0055] (3) Effectively reducing side reactions and improving safety

[0056] By adding the second type of modification elements in the ball milling stage, the present application constructs a high-stability covering layer on the material surface, significantly reduces the side reactions between the positive electrode and the electrolyte, and improves the thermal runaway threshold of the material in the high-voltage range. The oxygen evolution temperature of the material shifts to a higher temperature range, showing more excellent safety characteristics, which can meet the high safety requirements of power and energy storage applications.

[0057] (4) Suitable for various battery packaging and application occasions

[0058] The modified high-nickel ternary positive material of the present application can be applied to CR2032 button cells, soft packages, cylindrical, square and other packaging forms, so as to obtain excellent performance in research and development and mass production. Its high specific capacity, high thermal stability and long cycle life characteristics are suitable for the needs of power batteries, energy storage systems and consumer electronics in multiple fields.

[0059] (5) Good process compatibility, easy to scale up

[0060] The modification is completed by a conventional precursor synthesis-milling-calcination process without additional introduction of high-cost or special equipment. The addition amount of the modified element is maintained in the range of 0.4-4wt% to achieve a balance between the improvement of safety performance and the controllability of cost. Only limited adjustment is needed on the existing positive electrode material production line to implement the present solution, thereby realizing the industrial application quickly.

[0061] In summary, the present application realizes the comprehensive upgrade of high-nickel ternary positive electrode material in cycle life, thermal safety and application adaptability by multi-stage modification element introduction and hierarchical process parameter setting. The material exhibits more stable capacity retention rate and lower thermal runaway risk under high-pressure working conditions, which can provide a positive electrode solution with high energy density and safety for new generation power batteries and large-scale energy storage systems. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 is the XRD pattern of the Ni 0.8 Co 0.1 Mn 0.1 (OH)2 ternary precursor prepared in Example 1.

[0063] Figure 2 is the XRD pattern of the modified high-nickel ternary positive electrode material prepared in Example 1.

[0064] Figure 3 is the SEM pattern of the modified high-nickel ternary positive electrode material prepared in Example 1. DETAILED DESCRIPTION

[0065] The present application will be further described below in conjunction with specific examples. It should be understood that the following examples are only used to illustrate the present application, and are not intended to limit the scope of the present application. Unless specifically indicated, the raw materials and reagents used in the following examples are well known to those skilled in the art and can be obtained by commercial channels.

[0066] Preparation of high-nickel ternary positive electrode material precursor

[0067] The method for preparing the high-nickel ternary positive electrode material precursor includes but is not limited to coprecipitation method, sol-gel method, hydrothermal method, and spray pyrolysis method.

[0068] I. Coprecipitation method

[0069] The nickel source, cobalt source and manganese source are weighed according to the proportion, dissolved in deionized water, and the first type of modified element is added as needed. Hydroxide (sodium hydroxide, potassium hydroxide, etc.) is used as a precipitant, and ammonia solution is used as a complexing agent. The co-precipitation temperature is 30-100°C, and the solution pH is 8-14. The metal ions are uniformly precipitated to form a uniform precipitate. The precipitate is then washed, filtered and dried (70-130°C, 1-12 hours) to obtain a precursor powder. Preferably, the co-precipitation temperature is 40-90°C, and the pH is 9-13; more preferably, the co-precipitation temperature is 50-80°C, and the pH is 10-12. If the first type of modified element needs to be partially / fully added at the precursor stage, the corresponding salt of the first type of modified element can be dissolved in the metal salt solution for co-precipitation. The salt corresponding to the first type of modified element includes but is not limited to nitrate, chloride, sulfate or acetate, etc.

[0070] II. Sol-gel method

[0071] The nickel source, cobalt source and manganese source are weighed according to the proportion, and the first type of modified element is added as needed. The mixture is mixed with a complexing agent to form a uniform sol. The obtained sol is evaporated by heating to form a gel. The gel is sintered at 500-800°C to obtain a precursor. The sintering temperature is 400-900°C, and the sintering time is 1-12 hours. Preferably, the sintering temperature is 500-800°C, and the sintering time is 1-10 hours. More preferably, the sintering temperature is 550-750°C, and the sintering time is 2-8 hours. If the first type of modified element needs to be introduced at the same time, its salt can be added during the preparation of the sol to ensure the dispersion of the element.

[0072] III. Hydrothermal method

[0073] The nickel source, cobalt source and manganese source are weighed according to the proportion, dissolved in deionized water, and the first type of modified element is added as needed. The solution pH is adjusted to 5-8, and the solution is placed in a high-pressure reaction kettle for reaction. The hydrothermal temperature is 130-260°C, and the reaction time is 6-72 hours. After the reaction is completed, the solution is cooled, filtered and dried to obtain a high-nickel ternary precursor. Preferably, the hydrothermal temperature is 180-200°C, and the reaction time is 12-48 hours. More preferably, the hydrothermal temperature is 185-195°C, and the reaction time is 16-36 hours.

[0074] IV. Spray pyrolysis method

[0075] The nickel source, cobalt source and manganese source are weighed according to the proportion, dissolved in deionized water to form a uniform solution, and the first type of modified element is added as needed. The solution is atomized by a spray device, and a high-nickel ternary battery precursor is directly generated by pyrolysis reaction at 700-900°C. Preferably, the pyrolysis temperature is 750-850°C.

[0076] The precursor prepared by the above method has the characteristics of regular crystal morphology, uniform particle distribution and good dispersibility, and is suitable for the preparation of high-performance lithium ion battery positive electrode materials. The particle size D50 of the prepared precursor powder can be in the range of 1-20 μm. Preferably, D50 is 3-15 μm. More preferably, D50 is 5-10 μm. Ensuring that the precursor powder has regular particle morphology and good dispersibility facilitates subsequent ball milling and calcination.

[0077] Example 1

[0078] The nickel source, cobalt source and manganese source are synthesized into Ni 0.8 Co 0.1 Mn 0.1 (OH)2precursor according to a molar ratio of 0.8:0.1:0.1. Accurately weigh 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 33.81 g of manganese sulfate monohydrate, respectively, dissolve them in an appropriate amount of deionized water to prepare a mixed metal salt solution with a concentration of 2 mol / L. Add 1 L of 4 mol / L sodium hydroxide solution as a precipitant and 0.4 L of 7 mol / L ammonia solution as a complexing agent. The co-precipitation temperature is 60°C and the pH is 11, which allows the metal ions to uniformly precipitate and form a uniform precipitate. The precipitate is then washed, filtered and dried (70-130°C for 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility. The powder particle size D50 is in the range of 1-20 μm.

[0079] Weigh 115.5 g of the ternary precursor, 48.8 g of lithium carbonate, 0.58 g of modified tungsten acid ammonium and 1.2 g of tellurium dioxide into a ball milling tank, with a ball-to-material ratio of 6:1. After mixing uniformly at 500 r / min for 6 hours, dry the mixture in a forced air drying oven at 70°C for 4 hours.

[0080] After the dried material is placed in a crucible and calcined at 450°C for 6 hours in an oxygen atmosphere, the temperature is increased (at a rate of 2°C / min) to 750°C and held for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0081] Example 2

[0082] The nickel source, cobalt source and manganese source are synthesized into Ni 0.8 Co 0.1 Mn 0.1A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 33.81 g of manganese sulfate monohydrate in a proper amount of deionized water, respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60°C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, with a powder particle size D50 ranging from 1 to 20 μm.

[0083] The ternary precursor 115.5 g, lithium carbonate 48.8 g, modifier ammonium tungstate 1.2 g and telluric acid 1.2 g were weighed into a ball mill jar and ball milled at a ball-to-material ratio of 10:1 and 300 r / min for 8 hours. After mixing uniformly, the mixture was placed in a forced air drying oven at 80°C for 6 hours for drying.

[0084] The dried material was placed in a crucible and calcined at a low temperature of 525°C in an oxygen atmosphere for 5 hours, and then the temperature was increased (at a rate of 6°C / min) to 750°C and held for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0085] Example 3

[0086] A high-nickel ternary positive electrode material precursor (Ni 0.8 Co 0.1 Mn 0.1 A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 33.81 g of manganese sulfate monohydrate in a proper amount of deionized water, respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60°C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, with a powder particle size D50 ranging from 1 to 20 μm.

[0087] The ternary precursor 115.5 g, lithium carbonate 48.8 g, modifier ammonium tungstate 2.31 g and tellurium dioxide 1.2 g were weighed into a ball mill jar and ball milled at a ball-to-material ratio of 15:1 and 700 r / min for 4 hours. After mixing uniformly, the mixture was placed in a forced air drying oven at 60°C for 10 hours for drying.

[0088] The obtained material is placed in a crucible and calcined at 500 DEG C for 5 hours in an oxygen atmosphere, then heated (at a heating rate of 3 DEG C / min) to 780 DEG C and kept for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0089] Example 4

[0090] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.8:0.1:0.1 to obtain a Ni 0.8 Co 0.1 Mn 0.1 (OH)2 precursor. 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 33.81 g of manganese sulfate monohydrate are accurately weighed and dissolved in deionized water to prepare a mixed metal salt solution with a concentration of 2 mol / L. 1 L of sodium hydroxide solution with a concentration of 4 mol / L is added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L is added as a complexing agent. The co-precipitation temperature is 60 DEG C, and the pH is 11. The metal ions are uniformly precipitated to form a uniform precipitate. The precipitate is washed, filtered and dried (at 70-130 DEG C for 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 is in the range of 1-20 μm.

[0091] The ternary precursor 115.5 g, lithium carbonate 50.8 g, modifier ammonium niobate 2.9 g and germanium dioxide 0.29 g are weighed into a ball mill jar, the ball-to-material ratio is 15:1, and the mixture is uniformly ball milled at 450 r / min for 4 hours, then placed in a forced air drying oven at 65 DEG C for 9 hours for drying.

[0092] The obtained material is placed in a crucible and calcined at 530 DEG C for 5 hours in an oxygen atmosphere, then heated (at a heating rate of 6 DEG C / min) to 800 DEG C and kept for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0093] Example 5

[0094] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.8:0.1:0.1 to obtain a Ni 0.8 Co 0.1 Mn 0.1A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 33.81 g of manganese sulfate monohydrate in a proper amount of deionized water respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60°C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm.

[0095] The ternary precursor 115.5 g, lithium carbonate 50.8 g, modifier zirconic acid 0.58 g and sodium arsenate 1.2 g were weighed into a ball mill jar, the ball-to-material ratio was 30:1, and the mixture was uniformly mixed by ball milling at 300 r / min for 2 hours and then dried in a forced air drying oven at 80°C for 6 hours.

[0096] The dried material was placed in a crucible and calcined at a low temperature of 490°C in an oxygen atmosphere for 7 hours, and then the temperature was increased (at a rate of 10°C / min) to 790°C and kept for 14 hours to obtain the modified high-nickel ternary positive electrode material.

[0097] Example 6

[0098] A Ni 0.8 Co 0.1 Mn 0.1 A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 33.81 g of manganese sulfate monohydrate in a proper amount of deionized water respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60°C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm.

[0099] The ternary precursor 115.5 g, lithium carbonate 50.8 g, modifier sodium tantalate 0.29 g and diantimony trioxide 2.9 g were weighed into a ball mill jar, the ball-to-material ratio was 25:1, and the mixture was uniformly mixed by ball milling at 600 r / min for 4 hours and then dried in a forced air drying oven at 80°C for 9 hours.

[0100] The obtained material is placed in a crucible and calcined at 550℃ for 7 hours in an oxygen atmosphere, then heated (at a heating rate of 3℃ / min) to 850℃ and kept for 18 hours, to obtain the modified high-nickel ternary positive electrode material.

[0101] Example 7

[0102] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.8:0.1:0.1 to obtain a Ni 0.8 Co 0.1 Mn 0.1 (OH)2precursor. 420.61g of nickel sulfate hexahydrate, 56.23g of cobalt sulfate heptahydrate and 33.81g of manganese sulfate monohydrate are accurately weighed and dissolved in deionized water to prepare a mixed metal salt solution with a concentration of 2mol / L. 1L of 4mol / L sodium hydroxide solution is added as a precipitant, and 0.4L of 7mol / L ammonia solution is added as a complexing agent. The co-precipitation temperature is 60℃, and the pH is 11. The metal ions are uniformly precipitated to form a uniform precipitate. The precipitate is then washed, filtered and dried (at 70-130℃ for 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, with a powder particle size D50 in the range of 1-20μm.

[0103] The ternary precursor 115.5g, lithium carbonate 50.8g, modifier sodium perrhenate 0.462g and tellurium dioxide 2.31g are weighed into a ball mill jar, the ball-to-material ratio is 6:1, and the mixture is uniformly ball milled at 500r / min for 12 hours, then placed in a forced air drying oven at 120℃ for 1 hour for drying.

[0104] The obtained material is placed in a crucible and calcined at 500℃ for 8 hours in an oxygen atmosphere, then heated (at a heating rate of 3℃ / min) to 810℃ and kept for 12 hours, to obtain the modified high-nickel ternary positive electrode material.

[0105] Example 8

[0106] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.85:0.1:0.05 to obtain a Ni 0.85 Co 0.1 Mn 0.05A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 446.9 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 16.9 g of manganese sulfate monohydrate in a proper amount of deionized water respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60 °C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130 °C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm.

[0107] The ternary precursor 115.5 g, lithium carbonate 50.8 g, modifier tungsten ammonium 0.58 g and selenium dioxide 1.2 g were weighed into a ball mill jar and ball milled. The ball-to-material ratio was 8:1, and the ball milling was performed at 600 r / min for 6 hours. After mixing uniformly, the mixture was placed in a forced air drying oven at 85 °C for 6 hours for drying.

[0108] The dried material was placed in a crucible and calcined at a low temperature of 530 °C in an oxygen atmosphere for 8 hours. Then the temperature was increased (at a rate of 6 °C / min) to 800 °C and kept for 10 hours to obtain the modified high-nickel ternary positive electrode material.

[0109] Example 9

[0110] A high-nickel ternary positive electrode material precursor (Ni 0.85 Co 0.1 Mn 0.05 A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 446.9 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 16.9 g of manganese sulfate monohydrate in a proper amount of deionized water respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60 °C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130 °C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm.

[0111] The ternary precursor 115.5 g, lithium carbonate 50.8 g, modifier tungsten ammonium 0.58 g and selenium dioxide 1.2 g were weighed into a ball mill jar and ball milled. The ball-to-material ratio was 8:1, and the ball milling was performed at 600 r / min for 6 hours. After mixing uniformly, the mixture was placed in a forced air drying oven at 85 °C for 6 hours for drying.

[0112] The obtained material is placed in a crucible and calcined at 500 DEG C for 10 hours in an oxygen atmosphere, then heated (at a heating rate of 6 DEG C / min) to 800 DEG C and kept for 10 hours, to obtain the modified high-nickel ternary positive electrode material.

[0113] Example 10

[0114] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.85:0.1:0.05 to obtain a Ni 0.85 Co 0.1 Mn 0.05 (OH)2 precursor. 446.9 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 16.9 g of manganese sulfate monohydrate are accurately weighed and dissolved in deionized water to prepare a mixed metal salt solution with a concentration of 2 mol / L. 1 L of 4 mol / L sodium hydroxide solution is added as a precipitant, and 0.4 L of 7 mol / L ammonia solution is added as a complexing agent. The co-precipitation temperature is 60 DEG C, and the pH is 11. The metal ions are uniformly precipitated to form a uniform precipitate. The precipitate is washed, filtered and dried (at 70-130 DEG C for 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, with a powder particle size D50 ranging from 1 to 20 μm.

[0115] The ternary precursor 115.5 g, lithium carbonate 48.8 g, modifier ammonium molybdate 0.10 g and selenic acid 0.13 g are weighed into a ball mill jar, mixed uniformly at a ball-to-material ratio of 6:1 and a ball milling speed of 500 r / min for 6 hours, and then placed in a forced air drying oven at 70 DEG C for 4 hours for drying.

[0116] The obtained material is placed in a crucible and calcined at 500 DEG C for 10 hours in an oxygen atmosphere, then heated (at a heating rate of 6 DEG C / min) to 800 DEG C and kept for 10 hours, to obtain the modified high-nickel ternary positive electrode material.

[0117] Example 11

[0118] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.85:0.1:0.05 to obtain a Ni 0.85 Co 0.1 Mn 0.05A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 446.9 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 16.9 g of manganese sulfate monohydrate in a proper amount of deionized water respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60 °C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130 °C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm.

[0119] The ternary precursor 115.5 g, lithium carbonate 46.65 g, modifier ammonium niobate 1.2 g, selenic acid 0.58 g and germanium dioxide 0.58 g were weighed into a ball mill jar, the ball-to-material ratio was 20:1, and the mixture was uniformly mixed by ball milling at 500 r / min for 6 hours, and then was placed in a blast drying oven at 70 °C for 4 hours for drying.

[0120] The dried material was placed in a crucible and calcined at a low temperature of 500 °C in an oxygen atmosphere for 6 hours, and then was heated (heating rate 6 °C / min) to 820 °C and kept for 10 hours to obtain the modified high-nickel ternary positive electrode material.

[0121] Example 12

[0122] A high-nickel ternary positive electrode material precursor (Ni 0.85 Co 0.1 Mn 0.05 A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 446.9 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 16.9 g of manganese sulfate monohydrate in a proper amount of deionized water respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60 °C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130 °C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm.

[0123] The ternary precursor 115.5 g, lithium carbonate 46.65 g, modifier ammonium niobate 1.2 g, selenic acid 0.58 g and germanium dioxide 0.58 g were weighed into a ball mill jar, the ball-to-material ratio was 20:1, and the mixture was uniformly mixed by ball milling at 500 r / min for 6 hours, and then was placed in a blast drying oven at 70 °C for 4 hours for drying.

[0124] The obtained material is placed in a crucible and calcined at 480°C for 5 hours in an oxygen atmosphere, then heated (heating rate 6°C / min) to 780°C and kept for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0125] Example 13

[0126] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.78:0.12:0.1 to obtain a Ni 0.78 Co 0.12 Mn 0.1 (OH)2precursor. 410.09 g of nickel sulfate hexahydrate, 67.47 g of cobalt sulfate heptahydrate and 16.90 g of manganese sulfate monohydrate are accurately weighed and dissolved in deionized water to prepare a mixed metal salt solution with a concentration of 2 mol / L. 1 L of 4 mol / L sodium hydroxide solution is added as a precipitant, and 0.4 L of 7 mol / L ammonia solution is added as a complexing agent. The co-precipitation temperature is 60°C, and the pH is 11. The metal ions are uniformly precipitated to form a uniform precipitate. The precipitate is then washed, filtered and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, with a powder particle size D50 ranging from 1 to 20 μm.

[0127] The ternary precursor 115.5 g, lithium carbonate 46.65 g, modifier ammonium tungstate 0.29 g, ammonium molybdate 0.29 g and telluric acid 1.2 g are weighed into a ball mill jar, the ball-to-material ratio is 18:1, and the mixture is uniformly ball milled at 500 r / min for 5 hours, then placed in a forced air drying oven at 80°C for 4 hours for drying.

[0128] The obtained material is placed in a crucible and calcined at 480°C for 5 hours in an oxygen atmosphere, then heated (heating rate 6°C / min) to 780°C and kept for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0129] Example 14

[0130] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.78:0.12:0.1 to obtain a Ni 0.78 Co 0.12 Mn 0.1A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 410.09 g of nickel sulfate hexahydrate, 67.47 g of cobalt sulfate heptahydrate and 16.90 g of manganese sulfate monohydrate in a proper amount of deionized water respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60 °C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130 °C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm.

[0131] The ternary precursor 115.5 g, lithium carbonate 53.11 g, modifier ammonium molybdate 0.58 g and tellurium dioxide 1.2 g were weighed into a ball mill jar, the ball-to-material ratio was 12:1, and they were mixed uniformly at 500 r / min for 6 hours and then placed in a forced air drying oven at 80 °C for 4 hours for drying.

[0132] The dried material was placed in a crucible and calcined at a low temperature of 470 °C in an oxygen atmosphere for 5 hours, and then the temperature was increased (at a rate of 6 °C / min) to 780 °C and held for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0133] Example 15

[0134] A Ni 0.78 Co 0.12 Mn 0.1 A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 410.09 g of nickel sulfate hexahydrate, 67.47 g of cobalt sulfate heptahydrate and 16.90 g of manganese sulfate monohydrate in a proper amount of deionized water respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60 °C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130 °C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm.

[0135] The ternary precursor 115.5 g, lithium carbonate 53.11 g, modifier ammonium molybdate 0.77 g, ammonium niobate 0.77 g, zirconium acid 0.77 g and tellurium dioxide 2.31 g were weighed into a ball mill jar, the ball-to-material ratio was 6:1, and they were mixed uniformly at 500 r / min for 6 hours and then placed in a forced air drying oven at 80 °C for 4 hours for drying.

[0136] The dried material was placed in a crucible and calcined at 480°C in an oxygen atmosphere for 5 hours. Then, the temperature was increased (heating rate 6°C / min) to 780°C and held for 12 hours to obtain the modified high-nickel ternary cathode material.

[0137] Example 16

[0138] Ni was synthesized from nickel, cobalt, and manganese sources in a molar ratio of 0.85:0.1:0.05. 0.85 Co 0.1 Mn 0.05 The (OH)₂ precursor was prepared by accurately weighing 446.9 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate, and 16.9 g of manganese sulfate monohydrate, and dissolving them in an appropriate amount of deionized water to prepare a mixed metal salt solution with a concentration of 2 mol / L. 1 L of 4 mol / L sodium hydroxide solution was added as a precipitant, and 0.4 L of 7 mol / L ammonia solution was added as a complexing agent. The co-precipitation temperature was 60℃, and the pH was 11, to ensure uniform precipitation of the metal ions and form a homogeneous precipitate. The precipitate was then washed, filtered, and dried (70–130℃, 1–12 hours) to obtain a high-nickel ternary cathode material precursor with regular morphology and good dispersibility, with a powder particle size D50 ranging from 1 to 20 μm. 0.58 g of ammonium tungstate, the first type of modifier, was added entirely during the precursor synthesis stage.

[0139] Weigh 115.5g of modified ternary precursor, 48.8g of lithium carbonate, and 0.57g of second-type modifier tellurium dioxide and add them to a ball mill jar. The ball-to-material ratio is 6:1. Ball mill at 500r / min for 6 hours to mix evenly. Then place the mixture in a forced-air drying oven at 80℃ for 4 hours to dry.

[0140] The dried material was placed in a crucible and calcined at 480°C in an oxygen atmosphere for 5 hours. Then, the temperature was increased (heating rate 6°C / min) to 780°C and held for 12 hours to obtain the modified high-nickel ternary cathode material.

[0141] Example 17

[0142] Ni was synthesized from nickel, cobalt, and manganese sources in a molar ratio of 0.78:0.12:0.1. 0.78 Co 0.12 Mn 0.1A mixed metal salt solution with a concentration of 2 mol / L was prepared by dissolving 410.09 g of nickel sulfate hexahydrate, 67.47 g of cobalt sulfate heptahydrate and 16.90 g of manganese sulfate monohydrate in a proper amount of deionized water, respectively. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60°C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm. The first type of modifier, ammonium tungstate, 0.58 g, was added in the precursor synthesis stage.

[0143] The modified ternary precursor 115.5 g, lithium carbonate 48.8 g and the second type of modifier selenium acid 1.07 g were weighed into a ball milling tank, the ball-to-material ratio was 6:1, and the mixture was uniformly mixed by ball milling at 500 r / min for 6 hours and then dried in a blast drying oven at 80°C for 4 hours.

[0144] The dried material was placed in a crucible and calcined at a low temperature of 480°C in an oxygen atmosphere for 5 hours, and then the temperature was increased (at a rate of 6°C / min) to 780°C and kept for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0145] Example 18

[0146] A Ni 0.8 Co 0.1 Mn 0.1 (OH)2precursor was prepared by accurately weighing 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 33.81 g of manganese sulfate monohydrate, respectively, dissolving them in a proper amount of deionized water to prepare a mixed metal salt solution with a concentration of 2 mol / L. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60°C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was washed, filtered and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, and the powder particle size D50 was in the range of 1-20 μm. The first type of modifier, ammonium tungstate, 2.0 g, was added in the precursor synthesis stage.

[0147] The modified ternary precursor 115.5 g, lithium carbonate 48.8 g and the second type of modifier selenium acid 1.07 g were weighed into a ball milling tank, the ball-to-material ratio was 6:1, and the mixture was uniformly mixed by ball milling at 500 r / min for 6 hours and then dried in a blast drying oven at 80°C for 4 hours.

[0148] The obtained material is placed in a crucible and calcined at 480°C for 5 hours in an oxygen atmosphere, then heated (heating rate 6°C / min) to 780°C and held for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0149] Example 19

[0150] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.8:0.1:0.1 to obtain a Ni 0.8 Co 0.1 Mn 0.1 (OH)2precursor. Specifically, 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate and 33.81 g of manganese sulfate monohydrate are accurately weighed and dissolved in a proper amount of deionized water to prepare a mixed metal salt solution with a concentration of 2 mol / L. A 1L sodium hydroxide solution with a concentration of 4 mol / L is added as a precipitant, and a 0.4L ammonia solution with a concentration of 7 mol / L is added as a complexing agent. The co-precipitation temperature is 60°C, and the pH is 11. The metal ions are uniformly precipitated to form a uniform precipitate. The precipitate is then washed, filtered and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, with a powder particle size D50 ranging from 1 to 20 μm. A first type of modifier, ammonium molybdate, 0.58 g, is added during the precursor synthesis stage.

[0151] The modified ternary precursor 115.5 g, lithium carbonate 48.8 g, the second type of modifier selenium dioxide 1.1 g and the first type of modifier ammonium molybdate 0.58 g are weighed and added to a ball mill jar. The ball-to-material ratio is 6:1, and the mixture is uniformly mixed by ball milling at 500 r / min for 6 hours, then placed in a forced air drying oven at 80°C for 4 hours for drying.

[0152] The obtained material is placed in a crucible and calcined at 480°C for 5 hours in an oxygen atmosphere, then heated (heating rate 6°C / min) to 780°C and held for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0153] Example 20

[0154] The nickel source, cobalt source and manganese source are synthesized in a molar ratio of 0.8:0.1:0.1 to obtain a Ni 0.8 Co 0.1 Mn 0.1A mixed metal salt solution with a concentration of 2 mol / L was prepared by accurately weighing 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate, and 33.81 g of manganese sulfate monohydrate, respectively, and dissolving them in a proper amount of deionized water. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60°C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was then washed, filtered, and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility, with a powder particle size D50 ranging from 1 to 20 μm. The first type of modifier, ammonium tungstate, was added in an amount of 0.58 g during the synthesis of the precursor.

[0155] The modified ternary precursor 115.5 g, lithium carbonate 48.8 g, the second type of modifier selenium dioxide 1.1 g, and the first type of modifier ammonium tungstate 0.58 g were weighed into a ball milling tank. The ball-to-material ratio was 6:1, and the mixture was uniformly mixed by ball milling at 500 r / min for 6 hours and then dried in a forced air drying oven at 80°C for 4 hours.

[0156] The dried material was placed in a crucible and calcined at a low temperature of 480°C in an oxygen atmosphere for 5 hours, and then the temperature was increased to 780°C and maintained for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0157] Comparative Example 1

[0158] A Ni 0.8 Co 0.1 Mn 0.1 (OH)2precursor was synthesized by mixing nickel source, cobalt source, and manganese source in a molar ratio of 0.8:0.1:0.1. 420.61 g of nickel sulfate hexahydrate, 56.23 g of cobalt sulfate heptahydrate, and 33.81 g of manganese sulfate monohydrate were accurately weighed and dissolved in a proper amount of deionized water to prepare a mixed metal salt solution with a concentration of 2 mol / L. 1 L of sodium hydroxide solution with a concentration of 4 mol / L was added as a precipitant, and 0.4 L of ammonia solution with a concentration of 7 mol / L was added as a complexing agent. The co-precipitation temperature was 60°C, and the pH was 11. The metal ions were uniformly precipitated to form a uniform precipitate. The precipitate was then washed, filtered, and dried (70-130°C, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility.

[0159] The ternary precursor 115.5 g and lithium carbonate 48.8 g were weighed into a ball milling tank and ball milled. The mixture was uniformly mixed by ball milling at 500 r / min for 2 hours and then dried in a forced air drying oven at 70°C.

[0160] The obtained material is placed in a crucible and calcined at 480℃ for 5 hours in an oxygen atmosphere, then heated to 780℃ and kept for 12 hours to obtain the high-nickel ternary positive electrode material.

[0161] Comparative Example 2

[0162] The nickel source, cobalt source and manganese source are synthesized into Ni 0.8 Co 0.1 Mn 0.1 (OH)2precursor. The nickel sulfate hexahydrate 420.61g, cobalt sulfate heptahydrate 56.23g and manganese sulfate monohydrate 33.81g are accurately weighed and dissolved in deionized water to prepare a mixed metal salt solution with a concentration of 2mol / L. 1L of 4mol / L sodium hydroxide solution is added as a precipitant, and 0.4L of 7mol / L ammonia solution is added as a complexing agent. The co-precipitation temperature is 60℃, and the pH is 11. The metal ions are uniformly precipitated to form a uniform precipitate. The precipitate is washed, filtered and dried (70-130℃, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility.

[0163] The ternary precursor 115.5g, lithium carbonate 48.8g and modifier ammonium tungstate 1.2g are weighed into a ball mill jar and ball milled at 500r / min for 2 hours. After mixing uniformly, the material is placed in a forced air drying oven and dried at 70℃.

[0164] The obtained material is placed in a crucible and calcined at 480℃ for 5 hours in an oxygen atmosphere, then heated to 780℃ and kept for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0165] Comparative Example 3

[0166] The nickel source, cobalt source and manganese source are synthesized into Ni 0.8 Co 0.1 Mn 0.1 (OH)2precursor. The nickel sulfate hexahydrate 420.61g, cobalt sulfate heptahydrate 56.23g and manganese sulfate monohydrate 33.81g are accurately weighed and dissolved in deionized water to prepare a mixed metal salt solution with a concentration of 2mol / L. 1L of 4mol / L sodium hydroxide solution is added as a precipitant, and 0.4L of 7mol / L ammonia solution is added as a complexing agent. The co-precipitation temperature is 60℃, and the pH is 11. The metal ions are uniformly precipitated to form a uniform precipitate. The precipitate is washed, filtered and dried (70-130℃, 1-12 hours) to obtain a high-nickel ternary positive electrode material precursor with regular morphology and good dispersibility.

[0167] Take 115.5 g of ternary precursor, 48.8 g of lithium carbonate and 1.2 g of modifier tellurium dioxide into a ball mill tank and ball mill at 500 r / min for 2 hours. After mixing uniformly, place in a forced air drying oven at 70°C for drying.

[0168] After drying, place the obtained material in a crucible and low-temperature calcine at 480°C for 5 hours in an oxygen atmosphere, then heat to 780°C and keep for 12 hours to obtain the modified high-nickel ternary positive electrode material.

[0169] Performance test

[0170] Mix the high-nickel ternary positive electrode materials prepared in each example and comparative example, polyvinylidene fluoride and acetylene black according to a mass ratio of 8:1:1, add 5 mL of battery-grade N-methyl pyrrolidone, and then coat on an aluminum foil after stirring by an electric motor. Dry in a vacuum oven at 70°C for 12 hours, and punch into a circular electrode sheet with a diameter of 14 mm. Assemble CR2032 button cells in an argon-filled glove box, with lithium metal sheet as the counter electrode, the electrode sheet prepared from the high-nickel ternary positive electrode material as the positive electrode, together with a separator and an electrolyte. After standing for 24 hours, test the capacity retention rate, cycle life and safety characteristics of the battery at a current density of 0.05C (1C=220 mAh / g), a test temperature of room temperature, and a cutoff voltage of 2.8-4.3V to evaluate and test the cycle performance. The test results are shown in Table 1 below.

[0171] Table 1: Electrochemical performance table of positive electrode materials in each example and comparative example assembled into lithium ion batteries

[0172]

[0173]

[0174] As can be seen from the data in Table 1, the high-nickel ternary positive electrode materials obtained after partial or joint modification of the first type of element and the second type of element in Examples 1-20 have better electrochemical performance of the lithium ion batteries assembled therefrom than Comparative Example 1 (without any modification) and Comparative Examples 2-3 (only single type of element modification). The first cycle specific capacity and capacity retention rate of the lithium ion batteries assembled from the modified high-nickel ternary positive electrode materials of Examples 1-20 are significantly higher than those of Comparative Example 1.

[0175] As can be seen from Comparative Examples 1-10, the combination of the first type of modification element and the second type of modification element has an optimal ratio. Too large or too small ratio is difficult to achieve the best modification effect.

[0176] As can be seen from comparative examples 1-7, 8-12, 13-15, the ratio of the three elements nickel, cobalt and manganese in the precursor also affects the electrochemical performance of the positive electrode material. A high nickel content increases the capacity of the material, but reduces the capacity retention rate, and the internal structure of the material is unstable, resulting in poor cycle stability. Therefore, the nickel content of high-nickel ternary positive electrode materials needs to be controlled.

[0177] Examples 16-20 are prepared by adding the first type of modifying element during the preparation of the precursor and the ball milling stages respectively or simultaneously, and then adding the second type of modifying element. The electrochemical performance of the modified positive electrode materials assembled into lithium ion batteries is also superior to that of comparative example 1.

[0178] In summary, the first type of modifying element is solid-soluted or replaced in the material lattice after high-temperature calcination, significantly inhibiting cation mixing and micro-crack generation. The second type of modifying element is distributed on the surface of the material, forming a dense covering layer, reducing electrolyte corrosion and interface side reactions. The internal and external synergistic effects of the two types of modifying elements enable high-nickel materials to maintain stable structure and excellent cycle life in a high-voltage environment.

Claims

1. A modified high-nickel ternary cathode material, characterized in that, The modified high-nickel ternary cathode material comprises a host matrix and modifying elements. The host matrix is ​​made of a precursor, and the precursor has the general formula LiNi. x Co y Mn 1-x-y (OH) z Where 0.7≤x≤0.95, 0.02≤y≤0.25, 0≤z≤4; the modifying elements include a first type of modifying element and a second type of modifying element, wherein the first type of modifying element is one or more of W, Nb, Ta, Re, Mo, Hf, and Zr, and the second type of modifying element is one or more of Te, As, Ge, Sb, and Se. The first type of modifying element and the second type of modifying element are added in the form of compounds, and the total amount of the first type of modifying element compound and the second type of modifying element compound added is 0.2~4 wt% of the precursor, and the mass ratio of the first type of modifying element compound to the second type of modifying element compound is 1:10 to 10:1; The modified high-nickel ternary cathode material is prepared through the following steps: (1) Preparation of precursors: Add all or part of the first type of modifying elements during the precursor preparation stage; (2) Ball milling: The total molar amount of metal elements in the precursor powder is mixed with lithium elements in the lithium source at a molar ratio of 1:1 to 1:1.15, and the remaining first-class modifying elements and all second-class modifying elements are added. Then the mixture is ball milled and dried to obtain modified mixed powder. (3) Calcination: The dried material is calcined to obtain the modified high-nickel ternary cathode material; The calcination is a segmented calcination process, wherein the first stage is pre-calcination, which is held at 450~550℃ for 5~10 hours, and the second stage is main calcination, which is heated to 750~850℃ and held for 10~20 hours, with a heating rate of 2~10℃ / min, and the calcination atmosphere is oxygen or oxygen-enriched atmosphere.

2. The modified high-nickel ternary cathode material according to claim 1, characterized in that, The first type of modified element compound is an oxide, salt or heteropolyacid containing the first type of modified element, and the second type of modified element compound is an oxide, salt or heteropolyacid containing the second type of modified element.

3. The application of the modified high-nickel ternary cathode material as described in claim 1 or 2 in the preparation of lithium-ion batteries.

4. A lithium-ion battery comprising the modified high-nickel ternary cathode material as described in claim 1 or 2.

5. The method for preparing a lithium-ion battery as described in claim 4, characterized in that... Includes the following steps: (1) Preparation of battery positive electrode sheet: The modified high-nickel ternary positive electrode material, binder and conductive agent are prepared by pulping, coating, rolling and slicing process to obtain battery positive electrode sheet; (2) Battery assembly: The positive electrode, electrolyte, separator and negative electrode are assembled in sequence to form the lithium-ion battery.

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