Ternary system cathode material precursor, its preparation method, cathode material, cathode slurry material, lithium-ion battery, cathode, electrical equipment

Abstract

The present invention provides a ternary positive electrode material precursor, a preparation method thereof, a positive electrode material, a positive electrode slurry material, a lithium ion battery, a positive electrode, and an electrical device. The ternary positive electrode material precursor includes a core layer, an intermediate layer, and a shell layer, and the porosities of the core layer, the intermediate layer, and the shell layer increase in this order. The preparation method includes mixing raw materials including a nickel source, a cobalt source, a manganese source, a precipitant, and a complexing agent, and reacting the raw materials by a solution co-precipitation method. The positive electrode material includes a ternary positive electrode material precursor as a raw material. The positive electrode slurry material includes a positive electrode material as a raw material. The lithium ion battery positive electrode includes a lithium ion battery positive electrode slurry material as a raw material. The lithium ion battery includes a lithium ion battery positive electrode as a raw material. The electrical device includes a lithium ion battery. The ternary positive electrode material precursor and the positive electrode material according to the present disclosure have a special void distribution, which makes the structure of the material stable, reduces cracking of the material, and reduces phase change during cycling, thereby extending the service life of the material and improving the cycle performance and rate performance of the material.

Description

Technical Field

[0001] The present disclosure belongs to the field of lithium-ion batteries, and in particular, relates to a ternary cathode material precursor, a method for preparing the same, a cathode material, a cathode slurry material, a lithium-ion battery, a cathode, and an electrical equipment.

[0002] (Cross-reference to Related Applications) The present disclosure claims priority based on a Chinese application filed with the State Intellectual Property Office of China on December 28, 2021, with an application number of 202111623510.0 and a title of "Ternary Cathode Material Precursor and Method for Preparing the Same, Cathode Material, Cathode Slurry Material, Lithium-Ion Battery, Cathode, Electrical Equipment", and all of its content is incorporated herein by reference.

Background Art

[0003] Lithium-ion batteries are the next-generation high-energy and renewable green energy, with characteristics such as high operating voltage, large energy density, excellent safety, long cycle life, low self-discharge rate, and no memory effect. Therefore, they are widely applied in various fields of electric vehicles and large-scale energy storage. In recent years, with the rapid development of electric vehicles, the requirements for the energy density of lithium batteries have been increasing. In order to improve the cruising range of electric vehicles, the development of high-energy-density power batteries has become an urgent task.

[0004] The excellent performance of lithium-ion batteries in terms of cycle stability, capacity, voltage, etc. is mainly due to the prepared cathode material. Since the general cathode material has a low capacity, it limits the improvement of the overall capacity of the lithium-ion battery. Therefore, the development of a cathode material with high capacity, excellent rate performance, stable cycle performance, and excellent safety has become the focus and difficulty of research on lithium-ion batteries.

[0005] Among various lithium-ion battery cathode materials, the layered ternary cathode materials have advantages such as higher capacity, better cycle performance, and lower cost compared with general cathode materials. However, in the charge and discharge process, the structure is unstable, and the conversion from the spinel phase to the rock salt phase is likely to occur. Therefore, the capacity decay is too fast during the cycle process, and the thermal stability and safety are poor. Due to these drawbacks, the wide application of the layered ternary materials is restricted to a certain extent. Summary of the Invention

[0006] An object of the present disclosure is to provide a ternary cathode material precursor capable of solving the above problems, a preparation method thereof, a cathode material, a cathode slurry material, a lithium-ion battery, a cathode, and an electrical equipment.

[0007] To achieve the above object, the present disclosure adopts the following technical solutions.

[0008] A ternary cathode material precursor, comprising a core layer, an intermediate layer, and a shell layer, wherein the intermediate layer is a layer covering the core layer, the shell layer is a layer covering the intermediate layer, and the porosity of the core layer, the intermediate layer, and the shell layer increases in sequence.

[0009] Preferably, the porosity of the core layer is 5.4% - 17.1%, the porosity of the intermediate layer is 7.8% - 19.2%, the porosity of the shell layer is 9% - 20.1%. Preferably, the porosity of the core layer is 7.03% - 12.74%, the porosity of the intermediate layer is 8.7% - 13.6%, the porosity of the shell layer is 14.8% - 16.3%. Preferably, the radius of the core layer occupies 25% - 30% of the total radius, the thickness of the intermediate layer occupies 50% - 58.8% of the total radius, and the thickness of the shell layer occupies 11.2% - 25% of the total radius.

[0010] Preferably, the ternary cathode material precursor has a D50 of 7 - 15 μm and satisfies (D90 - D10) / D50 = 0.6 - 0.8.

[0011] Preferably, the ternary cathode material precursor has a half-value width of the 001 crystal plane of 0.4 to 0.88°, a half-value width of the 101 crystal plane of 0.25 to 0.61°, and preferably, the ternary cathode material precursor has a range of the ratio (I001 - I101) / I101 of FWHM of 0.1 to 0.9°.

[0012] Preferably, the BET / TD value of the ternary cathode material precursor is 3.90 to 6.66.

[0013] Preferably, the general formula of the ternary cathode material precursor is Ni x Co y Mn z Me (1-x-y-z) (OH) 2 where 0.6 ≤ x ≤ 1, 0 < y ≤ 1, 0 < z ≤ 1, and x + y + z ≤ 1 are satisfied, Me represents a doping element, and the doping element includes one or more of Al, Ti, V, W, Zr, Mg, Ce, Nb, and La. Preferably, the mass% content of the doping element is 0.01% to 10%.

[0014] The present disclosure further provides a method for preparing a ternary cathode material precursor. The preparation method includes mixing raw materials including a nickel source, a cobalt source, a manganese source, a precipitant, and a complexing agent, and performing a reaction by a solution coprecipitation method to obtain the ternary cathode material precursor.

[0015] Preferably, the nickel source includes nickel(II) sulfate, the cobalt source includes cobalt(II) sulfate, the manganese source includes manganese(II) sulfate, the precipitant includes one or more of sodium hydroxide, sodium carbonate, and sodium bicarbonate, and the complexing agent includes one or more of aqueous ammonia, sodium citrate, EDTA, and oxalic acid.

[0016] Preferably, the nickel source, the cobalt source, and the manganese source are premixed and used as a ternary metal salt solution. Preferably, the concentration of the ternary metal salt solution is 100 g / L to 130 g / L.

[0017] Preferably, the mixing includes mixing water, a precipitating agent, and a complexing agent to obtain a reaction base solution, and introducing the ternary metal salt solution, the complexing agent, and the precipitating agent into the reaction base solution. Preferably, the pH of the reaction base solution is 11 to 12.

[0018] Preferably, a protective gas is introduced into the reaction system.

[0019] Preferably, in the reaction, the pH of the system is 10 to 12, and the nickel in the supernatant liquid is controlled within the range of 0 to 500 ppm. Preferably, in the reaction, the pH of the system gradually decreases from 11.9 to 10.8 to 10.3.

[0020] Preferably, the temperature of the reaction is 40°C to 70°C, and preferably, the stirring speed of the reaction is 100 r / min to 600 r / min.

[0021] Preferably, the raw materials further include a doping element solution.

[0022] Preferably, the doping element in the doping element solution includes one or more of Al, Ti, V, W, Zr, Mg, Ce, Nb, and La. Preferably, the doping element is W, and the doping element solution includes sodium tungstate and sodium citrate. Preferably, the mass ratio of the sodium tungstate to the sodium citrate is 1 to 3:1.

[0023] Preferably, the method for preparing the ternary cathode material precursor further includes post-treatment, and the post-treatment includes alkali washing, water washing, and drying. Preferably, the volume ratio of the alkali washing agent for alkali washing to the water for water washing is V 水洗 :V アルカリ洗浄=(2~8):1 is satisfied, and the temperatures of alkali washing and water washing are each 30~70°C. Preferably, for the drying, the drying temperature is 100°C~180°C, and the moisture content after drying is made 0.4% or less.

[0024] The present disclosure further provides a positive electrode material. The positive electrode material includes a core, an intermediate region, and a shell. The intermediate region is a layer covering the core, the shell is a layer covering the intermediate region, and the porosity of the core, the intermediate region, and the shell increases in this order.

[0025] The present disclosure further provides a positive electrode slurry material. The raw materials of the positive electrode slurry material include the positive electrode material.

[0026] The present disclosure further provides a lithium-ion battery positive electrode. The raw materials of the lithium-ion battery positive electrode include the positive electrode slurry material.

[0027] The present disclosure further provides a lithium-ion battery. The raw materials of the lithium-ion battery include the lithium-ion battery positive electrode.

[0028] The present disclosure further provides an electrical equipment. The electrical equipment includes the lithium-ion battery.

[0029] Compared with the prior art, the present disclosure has the following beneficial effects.

[0030] The ternary positive electrode material precursor according to the present disclosure has a special pore distribution such that the porosity of the core layer, the intermediate layer, and the shell layer increases in this order. Therefore, the structure of the ternary material is stable, effectively suppressing cracking of the material and suppressing phase changes during the cycling process. As a result, the service life of the material can be extended, and the cycle performance, rate performance, and energy density of the material can be improved.

[0031] The method for preparing the ternary positive electrode material precursor according to the present disclosure has a simple process, low cost, and can achieve large-scale mass production.

[0032] The cathode material, cathode slurry material, lithium-ion battery cathode, and lithium-ion battery according to the present disclosure are excellent in stability, safety, and electrical performance.

[0033] The lithium-ion battery according to the present disclosure can be widely applied.

Brief Description of the Drawings

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Best Mode for Carrying Out the Invention

[0035] To more clearly explain the technical solutions of the embodiments of the present disclosure, the drawings necessary for the description of the embodiments will be briefly described below. It should be noted that the drawings to be described only show some embodiments of the present disclosure and do not limit the scope of the present disclosure.

[0036] The terms used in this specification are as follows.

[0037] "Prepared by" has the same meaning as "comprising". The terms "comprising", "including", "having", "containing" or any other variations thereof used in this specification mean non-exclusive inclusion. For example, a composition, step, method, product or apparatus comprising the recited elements may include not only these elements but also other elements not specified or the inherent elements in these compositions, steps, methods, products or apparatuses.

[0038] The phrase "consisting of" excludes elements, steps or compositions not specified. When used in a claim, the phrase is a closed type and means that it does not include materials other than the described materials except for related general impurities. When the phrase "consisting of" is used not in the claim subject but in a section of the claim content, it only limits the elements described in that section and does not exclude other elements from the entire claim.

[0039] When a quantity, concentration, or other value or parameter is represented by a range, a preferred range, or a range defined by a series of preferred upper and lower limit values, all ranges arbitrarily combined by any upper limit value or preferred value of any range and any lower limit value or preferred value of any range are specifically disclosed, regardless of whether there is a single disclosure. For example, when a range of "1 to 5" is disclosed, it should be interpreted to include ranges such as "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. The numerical ranges described in this specification include critical values and all integers and fractions within the range, unless otherwise specified.

[0040] In these examples, unless otherwise specified, parts and percentages are calculated by mass.

[0041] "Parts by mass" is a basic unit of measurement representing the mass ratio relationship of multiple components. One part can represent any unit mass, for example, it can represent 1 g, or it can represent 2.689 g, etc. If the parts by mass of component A is a parts and the parts by mass of component B is b parts, it represents that the mass ratio of component A to component B is a:b, or it represents that the mass of component A is aK and the mass of component B is bK (K is any number and represents a multiple factor). Note that different from mass%, the total parts by mass of all components is not necessarily 100 parts.

[0042] "And / or" means that at least one of the described situations occurs. For example, A and / or B includes "A and B" and "A or B".

[0043] A ternary cathode material precursor, comprising a core layer, an intermediate layer, and a shell layer, wherein the intermediate layer is a layer covering the core layer, the shell layer is a layer covering the intermediate layer, and the porosity of the core layer, the intermediate layer, and the shell layer increases in sequence.

[0044] Conventional materials have very dense voids both inside and outside, and their structure is unstable during the charge and discharge process, with poor stability and safety. In contrast, for the ternary cathode material precursor described above, when viewed from the cross-section, the porosity of the core layer, the intermediate layer, and the shell layer is not the same, and their porosity is configured to increase in sequence. As a result, the cycle performance of the ternary cathode material and the energy density per unit volume can be improved, and the structural stability of the material and the safety of the battery can be enhanced.

[0045] In an alternative embodiment, the porosity of the core layer is 5.4% - 17.1%, the porosity of the intermediate layer is 7.8% - 19.2%, and the porosity of the shell layer is 9% - 20.1%.

[0046] In an alternative embodiment, the porosity of the core layer is 7.03% - 12.74%, the porosity of the intermediate layer is 8.7% - 13.6%, and the porosity of the shell layer is 14.8% - 16.3%.

[0047] The materials according to the present disclosure are pretreated using the HITACHI IM4000 of the equipment, and SEM photographs are taken of the prepared samples using the HITACHI SU8100. To evaluate the characteristics of the porosity, the present disclosure directly obtains the void area and cross-sectional area of each region using image analysis software (ImageJ), and calculates the porosity of different regions using the formula (porosity = void area of each region / cross-sectional area of each region × 100%). All the porosities mentioned in the present disclosure are evaluated by this method.

[0048] Optionally, the porosity of the core layer is any value within the range of 5.4%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 17.1%, or 5.4% to 17.1%; the porosity of the intermediate layer is any value within the range of 7.8, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 19.2%, or 7.8% to 19.2%; and the porosity of the shell layer is any value within the range of 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 20.1%, or 9% to 20.1%.

[0049] In an optional embodiment, the voids in the intermediate layer and the shell layer are elongated.

[0050] In an optional embodiment, the widths of the voids in the intermediate layer and the shell layer gradually increase from the inside to the outside and are radially distributed as a whole.

[0051] The ternary cathode material to be prepared has different pore sizes from the inside to the outside, is porous, and has radially distributed voids. In this way, a lithium ion diffusion channel from the inside to the outside is formed. According to such a channel, it is beneficial for the diffusion of the electrolyte and the conduction of ions during the charge and discharge process. Therefore, it can contribute to the improvement of the capacity and can improve the rate performance of the battery to a certain extent.

[0052] In an optional embodiment, the radius of the core layer accounts for 25% to 30% of the overall radius, the thickness of the intermediate layer accounts for 50% to 58.8% of the overall radius, and the thickness of the shell layer accounts for 11.2% to 25% of the overall radius.

[0053] In an optional embodiment, the ternary cathode material precursor has a D50 of 7 to 15 μm and satisfies (D90 - D10) / D50 = 0.6 to 0.8 (where D10, D50, and D90 are the particle sizes when the cumulative values in the particle size distribution are 10%, 50%, and 90%, respectively).

[0054] Optionally, the D50 of the ternary cathode material precursor is any value within the range of 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, or 7 to 15 μm, and (D90 - D10) / D50 is any value within the range of 0.6, 0.7, 0.8, or 0.6 to 0.8.

[0055] In an alternative embodiment, the ternary cathode material precursor has a half-width (I001) of the 001 crystal plane in the range of 0.4 to 0.88°, and a half-width (I101) of the 101 crystal plane in the range of 0.25 to 0.61°.

[0056] Optionally, the ternary cathode material precursor has a half-width of the 001 crystal plane of 0.4°, 0.5°, 0.6°, 0.7°, 0.8°, 0.81°, 0.82°, 0.83°, 0.84°, 0.85°, 0.86°, 0.87°, 0.88°, or any value within the range of 0.4 to 0.88°, and a half-width of the 101 crystal plane of 0.25°, 0.3°, 0.35°, 0.4°, 0.45°, 0.5°, 0.55°, 0.56°, 0.57°, 0.58°, 0.59°, 0.60°, 0.61°, or any value within the range of 0.25 to 0.61°.

[0057] In an alternative embodiment, the range of the ratio (I001 - I101) / I101 of the full width at half maximum (FWHM) of the ternary cathode material precursor is 0.1 to 0.9.

[0058] Optionally, the value of the ratio (I001 - I101) / I101 of the FWHM is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or any value within the range of 0.1 to 0.9.

[0059] By controlling the values of the half-width and the ratio (I001 - I101) / I101 of the FWHM to improve the crystallinity and structure of the material, the primary particles can be refined, the decrease in particle density can be suppressed, and the packing density can be increased. Furthermore, it can contribute to the improvement of capacity and the cycle stability of the material, and can suppress the decrease in energy density.

[0060] In an optional embodiment, the BET (specific surface area) / TD (tap density) value of the ternary cathode material precursor is 3.90 to 6.66.

[0061] BET and TD satisfy a linear relationship. The larger the BET / TD value, the larger the porosity of the material. In this way, it can contribute to the improvement of the battery's safety, rate performance, and cycle performance.

[0062] Optionally, the BET / TD value is 3.90, 4, 5, 6, 6.66, or any value within the range of 3.90 to 6.66.

[0063] In an optional embodiment, the general formula of the ternary cathode material precursor is Ni x Co y Mn z Me (1-x-y-z) (OH) 2 where 0.6 ≤ x ≤ 1, 0 < y ≤ 1, 0 < z ≤ 1, and x + y + z ≤ 1 are satisfied, and Me represents a doping element, and the doping element includes one or more of Al, Ti, V, W, Zr, Mg, Ce, Nb, and La.

[0064] In an optional embodiment, the mass% content of the doping element is 0.01% to 10%.

[0065] When the content of Ni in the ternary cathode material precursor according to the present disclosure is 0.6 or more, it becomes a high-nickel material, which has the advantages of excellent cycle performance, large energy density, and excellent stability and safety. By introducing other metal elements such as Al, Ti, V, W, Zr, Mg, Ce, Nb, and La, the structural stability of the material can be improved, and the safety and cycle stability of the material can be improved.

[0066] Optionally, the mass percentage content of the doping element is any value within the range of 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, or 0.01% to 10%.

[0067] The present disclosure further provides a method for preparing a ternary cathode material precursor. The preparation method includes mixing raw materials including a nickel source, a cobalt source, a manganese source, a precipitant, and a complexing agent, and performing a reaction by a solution coprecipitation method to obtain the ternary cathode material precursor.

[0068] In an alternative embodiment, the nickel source includes nickel(II) sulfate, the cobalt source includes cobalt(II) sulfate, the manganese source includes manganese(II) sulfate, the precipitant includes one or more of sodium hydroxide, sodium carbonate, and sodium bicarbonate, and the complexing agent includes one or more of aqueous ammonia, sodium citrate, EDTA, and oxalic acid.

[0069] In an alternative embodiment, the nickel source, the cobalt source, and the manganese source are premixed and used as a ternary metal salt solution.

[0070] In an alternative embodiment, the concentration of the ternary metal salt solution is 100 g / L to 130 g / L.

[0071] Optionally, the concentration of the ternary metal salt solution is any value within the range of 100 g / L, 101 g / L, 102 g / L, 103 g / L, 104 g / L, 105 g / L, 106 g / L, 107 g / L, 108 g / L, 109 g / L, 110 g / L, 111 g / L, 112 g / L, 113 g / L, 114 g / L, 115 g / L, 116 g / L, 117 g / L, 118 g / L, 119 g / L, 120 g / L, 121 g / L, 122 g / L, 123 g / L, 124 g / L, 125 g / L, 126 g / L, 127 g / L, 128 g / L, 129 g / L, 130 g / L, or 100 g / L to 130 g / L.

[0072] In an alternative embodiment, the mixing includes mixing water, a precipitating agent, and a complexing agent to obtain a reaction base solution, and introducing the ternary metal salt solution, the complexing agent, and the precipitating agent into the reaction base solution.

[0073] In an alternative embodiment, the pH of the reaction base solution is 11 to 12.

[0074] Optionally, the pH of the reaction base solution is 11.0, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12.0, or any value within the range of 11 to 12.

[0075] In an alternative embodiment, a protective gas is introduced into the reaction system.

[0076] The protective gas is preferably nitrogen gas.

[0077] In an alternative embodiment, in the reaction, the pH of the system is 10 to 12, and nickel in the supernatant is controlled within the range of 0 to 500 ppm.

[0078] In an alternative embodiment, in the reaction, the pH of the system gradually decreases from 11.9 to 10.8 to 10.3.

[0079] Optionally, in the reaction, the pH of the system is 10, 10.5, 11, 11.5, 12, or any value within the range of 10 to 12, and nickel in the supernatant is 0 ppm, 50 ppm, 100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, or any value within the range of 0 to 500 ppm.

[0080] In an alternative embodiment, the temperature of the reaction is 40°C to 70°C.

[0081] In an alternative embodiment, the stirring speed of the reaction is 100 r / min to 600 r / min.

[0082] Optionally, the temperature of the reaction is any value within the range of 40°C, 50°C, 60°C, 70°C, or 40 - 70°C, and the stirring speed of the reaction is any value within the range of 100 r / min, 200 r / min, 300 r / min, 400 r / min, 500 r / min, 600 r / min, or 100 r / min - 600 r / min.

[0083] In an alternative embodiment, the raw material further includes a doping element solution.

[0084] In an alternative embodiment, the doping element in the doping element solution includes one or more of Al, Ti, V, W, Zr, Mg, Ce, Nb, and La.

[0085] In an alternative embodiment, the doping element is W, and the doping element solution includes sodium tungstate and sodium citrate.

[0086] In an alternative embodiment, the mass ratio of the sodium tungstate to the sodium citrate is 1 - 3:1.

[0087] Optionally, the mass ratio of the sodium tungstate to the sodium citrate is 1:1, 2:1, 3:1, or any value within the range of 1 - 3:1.

[0088] In an alternative embodiment, the method for preparing the ternary cathode material precursor further includes post-treatment, and the post-treatment includes alkali washing, water washing, and drying.

[0089] In an alternative embodiment, the volume ratio of the alkali washing agent for alkali washing to the water for water washing is V 水洗 :V アルカリ洗浄 =(2 - 8):1, and the temperatures of the alkali washing and the water washing are each 30 - 70°C.

[0090] In an optional embodiment, the drying is carried out at a temperature of 100°C to 180°C, and the moisture content after drying is made 0.4% or less.

[0091] Optionally, the volume ratio V 水洗 :V アルカリ洗浄 of the alkaline cleaning agent for the alkaline cleaning to the water for the water washing is any value within the range of 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, or (2 to 8):1. The temperatures of the alkaline cleaning and the water washing are each any value within the range of 30°C, 40°C, 50°C, 60°C, 70°C, or 30 to 70°C. The drying is carried out at a temperature of 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, or any value within the range of 100°C to 180°C, and the moisture content after drying is any value within the range of 0.1%, 0.2%, 0.3%, 0.4%, or 0.4% or less.

[0092] The present disclosure further provides a positive electrode material. The positive electrode material includes a core, an intermediate region, and a shell. The intermediate region is a layer covering the core, the shell is a layer covering the intermediate region, and the porosity of the core, the intermediate region, and the shell increases in order.

[0093] The present disclosure further provides a positive electrode slurry material. The raw materials of the positive electrode slurry material include the positive electrode material.

[0094] The present disclosure further provides a positive electrode for a lithium-ion battery. The raw materials of the positive electrode for a lithium-ion battery include the positive electrode slurry material.

[0095] The present disclosure further provides a lithium-ion battery. The raw materials of the lithium-ion battery include the positive electrode for a lithium-ion battery.

[0096] The present disclosure further provides an electrical equipment. The electrical equipment includes the lithium-ion battery.

[0097] Note that the electrical equipment here not only refers to the lithium-ion battery according to the present disclosure itself, but also refers to the case where the lithium-ion battery according to the present disclosure is used as an external power source or an energy carrier. That is, the electrical equipment here is the equipment directly or indirectly powered by the lithium-ion battery according to the present disclosure, or the equipment itself charges the lithium-ion battery according to the present disclosure as a power source.

[0098] Hereinafter, the technical solution of the present disclosure will be described in detail using specific examples. As will be understood by those skilled in the art, the following examples are only for explaining the present disclosure and do not limit the scope of the present disclosure. In the examples, for the conditions not specified specifically, it is possible to carry out under conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments used whose manufacturers are not specified, it is possible to use commercially available conventional products.

[0099] Example 1 (1) As the main raw materials and auxiliary materials, a ternary system solution (2 mol / L) prepared by uniformly mixing and stirring 79.98 kg of nickel(II) sulfate, 11.30 kg of cobalt(II) sulfate, and 4.06 kg of manganese(II) sulfate crystals with pure water, a tungsten solution of 0.91 g / L prepared by a predetermined amount of sodium tungstate and sodium citrate, a precipitant, and a complexing agent are used. Pure water, liquid caustic soda (mass concentration 32%), and aqueous ammonia (mass concentration 20.5%) are added to the reaction kettle to prepare a reaction base solution with a pH of 11.60 - 11.70. Nitrogen gas is introduced, and it is heated to 60 °C under the condition of a stirring speed of 539 r / min. The ternary system solution (4 L / h), liquid caustic soda (1.6 L / h), aqueous ammonia (0.22 L / h), and doping solution (2 L / h) are introduced at a predetermined flow rate. During the reaction process, the pH is controlled at 11.65 - 10.50, and the nickel content in the supernatant is controlled at 50 - 100 ppm. A tungsten-doped nickel cobalt manganese ternary precipitate with a median diameter D50 of 10 μm is obtained by the reaction.

[0100] (2) After solid-liquid separation of the reaction product, alkaline washing with a predetermined amount of detergent and water washing with a predetermined amount of water were performed until Na < 300 ppm and 2200 ppm < S < 2600 ppm, and the cake was taken out and prepared for use.

[0101] (3) The prepared cake was broken up and dried in a forced-air oven until the moisture content was less than 4000 ppm for dehydration, and then taken out and sealed for use.

[0102] (4) Sieving, iron removal and other treatments were performed on the obtained dried material to obtain a Ni 0.9 Co 0.06 Mn 0.04 (OH) 2 product.

[0103] (5) Under specified conditions, the obtained doped precursor material and lithium compound were mixed and sintered to prepare a doped cathode material.

[0104] Figure 1 is a schematic diagram of the obtained ternary cathode material precursor. Region A represents the core layer, region B represents the intermediate layer, and region C represents the shell layer. Figure 2 is an SEM photograph of the ternary cathode material precursor obtained in Example 1. Figure 3 is an SEM photograph of the cross-section of the ternary cathode material precursor obtained in Example 1. Figure 4 is the XRD spectrum of the ternary cathode material precursor obtained in Example 1, where the horizontal axis is the diffraction peak angle and the vertical axis is the diffraction peak intensity. Figure 5 is the differential distribution curve of the mesopore pore size of the ternary cathode material precursor obtained in Example 1.

[0105] Example 2 (1) As the main raw materials and auxiliary materials, a ternary solution (2 mol / L) prepared by uniformly mixing 84.82 kg of nickel(II) sulfate, 7.15 kg of cobalt(II) sulfate, and 4.67 kg of manganese(II) sulfate crystals with pure water and stirring, an aluminum solution of 1.47 g / L prepared with a predetermined amount of aluminum sulfate and sodium hydroxide, a precipitant, and a complexing agent are used. Pure water, liquid caustic soda (mass concentration 32%), and aqueous ammonia are added to a reaction kettle to prepare a reaction base solution with a pH of 11.60 - 11.70. Nitrogen gas is introduced, and it is heated to 60 °C under the condition of a stirring speed of 539 r / min. A ternary solution (4 L / h), liquid caustic soda (1.6 L / h), aqueous ammonia (0.31 L / h), and a doping solution (2 L / h) are introduced at a predetermined flow rate. During the reaction process, the pH is adjusted to 11.60 - 10.55, the nickel content in the supernatant is controlled to be 50 - 100 ppm, the stirring speed is gradually decreased from 539 r / min to 462 r / min, and an aluminum-doped nickel cobalt manganese ternary precipitate with a median diameter D50 of 12 μm is obtained by the reaction.

[0106] Step (2), Step (3), and Step (4) are the same as in Example 1, and thereby an Al(6000 ppm)-doped precursor product of Ni 0.88 Co 0.09 Mn 0.03 (OH) 2 is obtained.

[0107] Step (5) was the same as in Example 1.

[0108] Figure 6 is an SEM photograph of the ternary cathode material precursor obtained according to Example 2, and Figure 7 is an XRD spectrum of the ternary cathode material precursor obtained according to Example 2. The horizontal axis is the diffraction peak angle, and the vertical axis is the diffraction peak intensity.

[0109] Example 3 (1) As the main raw materials and auxiliary materials, a ternary system solution (2 mol / L) prepared by uniformly mixing 88.52 kg of nickel(II) sulfate, 5.10 kg of cobalt(II) sulfate, and 3.44 kg of manganese(II) sulfate crystals with pure water and stirring, a titanium solution of 2.0 g / L prepared by a predetermined amount of titanium(IV) oxysulfate, sodium citrate, and sulfuric acid, a precipitating agent, and a complexing agent are used. Pure water, liquid caustic soda (mass concentration 32%), and aqueous ammonia are added to the reaction kettle to prepare a reaction base solution with a pH of 11.60 - 11.70. Nitrogen gas is introduced, and it is heated to 60 °C under the condition of a stirring speed of 539 r / min. A ternary system solution (4 L / h), liquid caustic soda (1.6 L / h), aqueous ammonia (0.54 L / h), and a doping solution (2 L / h) are introduced at a predetermined flow rate. During the reaction process, the pH is adjusted to 11.65 - 11.00, the nickel content in the supernatant is controlled to be 50 - 100 ppm, the stirring speed is gradually decreased from 539 r / min to 308 r / min, and a titanium-doped nickel cobalt manganese ternary system precipitate with a median diameter D50 of 16 μm is obtained by the reaction.

[0110] Step (2), Step (3), and Step (4) are the same as those in Example 1, and thereby a Ni of the Ti(4000 ppm)-doped precursor product 0.92 Co 0.03 Mn 0.05 (OH) 2 is obtained.

[0111] Step (5) was the same as that in Example 1.

[0112] Figure 8 is an SEM photograph of the ternary cathode material precursor obtained according to Example 3, and Figure 9 is an XRD spectrum of the ternary cathode material precursor obtained according to Example 3. The horizontal axis is the diffraction peak angle, and the vertical axis is the diffraction peak intensity.

[0113] Example 4 (1) As the main raw materials and auxiliary materials, a ternary system solution (2 mol / L) prepared by uniformly mixing 91.26 kg of nickel(II) sulfate, 4.07 kg of cobalt(II) sulfate, and 2.22 kg of manganese(II) sulfate crystals with pure water and stirring, a zirconium solution of 3.67 g / L prepared by a predetermined amount of zirconium sulfate, sodium citrate, and sulfuric acid, a precipitating agent, and a complexing agent are used. Pure water, liquid caustic soda (mass concentration 32%), and aqueous ammonia are added to a reaction kettle to prepare a reaction base solution with a pH of 11.60 - 11.70. Nitrogen gas is introduced, and under the condition of a stirring speed of 539 r / min, it is heated to 60 °C, and a ternary system solution (4 L / h), liquid caustic soda (1.6 L / h), aqueous ammonia (0.6 L / h), and a doping solution (2 L / h) are introduced at a predetermined flow rate. During the reaction process, the pH is adjusted to 11.65 - 10.30, the nickel in the supernatant is controlled to 0 - 200 ppm, the stirring speed is gradually decreased from 539 r / min to 231 r / min, and a zirconium-doped nickel cobalt manganese ternary system precipitate with a median diameter D50 of 16 μm is obtained by the reaction.

[0114] Step (2), Step (3), and Step (4) are the same as those in Example 1, and thereby a Ni of a Zr(10000 ppm)-doped precursor product 0.94 Co 0.04 Mn 0.02 (OH) 2 is obtained.

[0115] Step (5) was the same as that in Example 1.

[0116] Figure 10 is an SEM photograph of the ternary cathode material precursor obtained according to Example 4, and Figure 11 is an XRD spectrum of the ternary cathode material precursor obtained according to Example 4, where the horizontal axis is the diffraction peak angle and the vertical axis is the diffraction peak intensity.

[0117] Example 5 (1) As the main raw materials and auxiliary materials, a ternary system solution (2 mol / L) prepared by uniformly mixing 85.61 kg of nickel(II) sulfate, 6.15 kg of cobalt(II) sulfate, and 2.45 kg of manganese(II) sulfate crystals with pure water and stirring, and a precipitant and a complexing agent are used. Pure water, liquid caustic soda (mass concentration 32%), and aqueous ammonia (mass concentration 20.5%) are added to the reaction kettle to prepare a reaction base solution with a pH of 11.60 - 11.70. Nitrogen gas is introduced, and under the condition of a stirring speed of 539 r / min, it is heated to 60 °C, and a ternary system solution (4 L / h), liquid caustic soda (1.6 L / h), aqueous ammonia (0.22 L / h), and a doping solution (2 L / h) are introduced at a predetermined flow rate. During the reaction process, the pH is controlled at 11.65 - 10.50, and the nickel content in the supernatant is controlled at 50 - 100 ppm. A nickel cobalt manganese ternary system precipitate with a median diameter D50 of 10 μm is obtained by the reaction.

[0118] Steps (2), (3), and (4) are the same as those in Example 1, and thereby the Ni of the precursor product 0.905 Co 0.057 Mn 0.038 (OH) 2 is obtained.

[0119] Step (5) was the same as that in Example 1.

[0120] Figure 12 is an SEM photograph of the ternary cathode material precursor obtained according to Example 5, and Figure 13 is an XRD spectrum of the ternary cathode material precursor obtained according to Example 5. The horizontal axis is the diffraction peak angle, and the vertical axis is the diffraction peak intensity.

[0121] Comparative Example 1 In the reaction process of (1), the stirring speed is set to 616.4 r / min, and the flow rates of the materials are such that the ternary system solution is 1 L / h, liquid caustic soda is 0.4 L / h, and aqueous ammonia is 0.05 L / h. The others are the same as those in Example 5, and thereby the chemical formula is Ni 0.905 Co 0.057 Mn 0.038 (OH)2 A precursor product was obtained.

[0122] Comparative Example 2 (1) In the reaction process, the flow rate of the ternary solution was gradually increased from 1 L / h to 4 L / h, the flow rate of liquid caustic soda was gradually increased from 0.4 L / h to 1.6 L / h, and the flow rate of aqueous ammonia was gradually increased from 0.12 L / h to 0.16 L / h. Other conditions were the same as in Example 5. As a result, a precursor product with the chemical formula Ni 0.905 Co 0.057 Mn 0.038 (OH) 2 was obtained.

[0123] Comparative Example 3 (1) In the reaction process, the flow rate of the ternary solution was set to 2 L / h, the flow rate of liquid caustic soda was set to 0.8 L / h, and the flow rate of aqueous ammonia was set to 0.12 L / h. Other conditions were the same as in Example 5. As a result, a precursor product with the chemical formula Ni 0.905 Co 0.057 Mn 0.038 (OH) 2 was obtained.

[0124] Comparative Example 4 (1) In the reaction process, the flow rate of the ternary solution was gradually increased from 2 L / h to 7 L / h, the flow rate of liquid caustic soda was gradually increased from 0.8 L / h to 2.8 L / h, and the flow rate of aqueous ammonia was gradually increased from 0.12 L / h to 0.28 L / h. Other conditions were the same as in Example 5. As a result, a precursor product with the chemical formula Ni 0.905 Co 0.057 Mn 0.038 (OH) 2 was obtained.

[0125] Control Example 1 (1) In the reaction process, the flow rate of aqueous ammonia was gradually decreased from 0.54 L / h to 0.40 L / h. Other conditions were the same as in Example 5. As a result, a precursor product with the chemical formula Ni 0.905 Co 0.057 Mn 0.038 (OH) 2 was obtained.

[0126] Comparative Example 2 (1) In the reaction process, the stirring speed was gradually decreased from 693.7 r / min to 539.7 r / min, and the others were the same as in Example 5. As a result, a precursor product with the chemical formula Ni 0.905 Co 0.057 Mn 0.038 (OH) 2 was obtained.

[0127] The results of measurements on the parameters and performance of the materials obtained by each of the Examples, Comparative Examples, and Comparative Examples are shown in Table 1.

[0128] [Table 1]

[0129] [Table 2]

[0130] From the data in Table 1 and Table 2, in Examples 1 to 5, a doped type high nickel ternary cathode material having a special pore distribution was obtained. The precursor material prepared in the Examples had a porosity in Region A of 7.3% to 16.9%, a porosity in Region B of 8.8% to 17.6%, a porosity in Region C of 12.5% to 19.8%, a ratio of XRD half-value widths (I001 - I101) / I101 of 0.397 to 0.489, a BET / TD of 4.14 to 6.04. It can be confirmed that the battery manufactured with the cathode material has a capacity retention rate of 97% or more, and the (1C / 0.1C) rate is maintained at 96% or more, and has excellent cycle characteristics and rate performance.

[0131] In the other party and Comparative Examples 1 to 4, a doped type high nickel ternary cathode material having a special void distribution was also prepared. In Comparative Example 1, the BET / TD was 3.90 to 6.84, the ratio of the XRD half-width (I001 - I101) / I101 was 0.1 to 0.9, the porosity of Region A was less than 5.4%, the porosity of Region B was less than 7.8%, and the porosity of Region C was less than 9%. In Comparative Example 2, the BET / TD was 3.90 to 6.84, the ratio of the XRD half-width (I001 - I101) / I101 was 0.1 to 0.9, the porosity of Region A was less than 5.4%, the porosity of Region B was less than 7.8%, and the porosity of Region C was less than 9%. In Comparative Example 3, the BET / TD was 3.90 to 6.84, the ratio of the XRD half-width (I001 - I101) / I101 was 0.1 to 0.9, the porosity of Region A was 5.4% to 17.1%, the porosity of Region B was 7.8% to 19.2%, and the porosity of Region C was less than 9%. In Comparative Example 4, the BET / TD was 3.90 to 6.84, the ratio of the XRD half-width (I001 - I101) / I101 was 0.1 to 0.9, the porosity of Region A was 5.4% to 17.1%, the porosity of Region B was 7.8%, and the porosity of Region C was 9% to 20.1%. Also, the battery manufactured with the said cathode material had a capacity retention rate of 94% or less, and the (1C / 0.1C) rate was maintained at 93% or less. Therefore, compared with Examples 1 to 5, the cycle characteristics and rate performance were relatively inferior.

[0132] Each of the above examples is only for explaining the technical solution of the present disclosure and does not limit it. Despite having described the present disclosure in detail with reference to each of the above examples, those skilled in the art may modify the technical solutions described in each of the above examples, or may perform equivalent substitutions for some or all of the technical features therein. These modifications or substitutions do not deviate the essence of the corresponding technical solution from the scope of the technical solutions of each example of the present disclosure.

[0133] In addition, some of the above embodiments have some features included in other embodiments. However, those skilled in the art will understand that a combination of features of different embodiments may also form another embodiment belonging to the scope of the present disclosure. For example, in the claims, the embodiments to be protected may be arbitrarily combined. The information disclosed in the background art section is for deepening the understanding of the entire background art of the present disclosure, and does not admit or imply in any form that it is prior art well-known to those skilled in the art.

Claims

1. A Ni-Co-Mn-based ternary cathode material precursor, comprising: a core layer, an intermediate layer, and a shell layer, wherein the intermediate layer is a layer covering the core layer, the shell layer is a layer covering the intermediate layer, and the porosity of the core layer, the intermediate layer, and the shell layer increases in sequence; the porosity of the core layer is 5.4% to 17.1%, the porosity of the intermediate layer is 7.8% to 19.2%, and the porosity of the shell layer is 9% to 20.1%. A ternary cathode material precursor characterized by the above.

2. The porosity of the core layer is 7.03% to 12.74%, the porosity of the intermediate layer is 8.7% to 13.6%, and the porosity of the shell layer is 14.8% to 16.3%. The ternary cathode material precursor according to Claim 1.

3. The radius of the core layer occupies 25% to 30% of the overall radius, the thickness of the intermediate layer occupies 50% to 58.8% of the overall radius, and the thickness of the shell layer occupies 11.2% to 25% of the overall radius. The ternary cathode material precursor according to Claim 1.

4. The D50 of the ternary cathode material precursor is 7 to 15 μm, and (D90 - D10) / D50 = 0.6 to 0.8 is satisfied. The ternary cathode material precursor according to Claim 1.

5. The ternary cathode material precursor has a half-value width of the 001 crystal plane of 0.4 to 0.88°, and a half-value width of the 101 crystal plane of 0.25 to 0.61°. The ternary cathode material precursor according to Claim 1.

6. The BET / TD value of the ternary cathode material precursor is 3.90 to 6.

66. The ternary cathode material precursor according to Claim 1.

7. The general formula of the ternary cathode material precursor is Ni ｘ Co ｙ Mn ｚ Me （１－ｘ－ｙ－ｚ） (OH) ２ where 0.6 ≤ x ≤ 1, 0 < y ≤ 1, 0 < z ≤ 1, and x + y + z ≤ 1 are satisfied, Me represents a doping element, and the doping element includes one or more of Al, Ti, V, W, Zr, Mg, Ce, Nb, and La The ternary cathode material precursor according to any one of Claims 1 to 6.

8. The mass% content of the doping element is 0.01% to 10%. The ternary cathode material precursor according to Claim 7.

9. A method for preparing the ternary cathode material precursor according to any one of Claims 1 to 8, comprising: mixing raw materials including a nickel source, a cobalt source, a manganese source, a precipitating agent, and a complexing agent, and performing a reaction by a solution coprecipitation method to obtain a ternary cathode material precursor; the complexing agent is aqueous ammonia; the flow rates of the nickel source, the cobalt source, and the manganese source are 4 L / h, the flow rate of the precipitating agent is 1.6 L / h, and the flow rate of the aqueous ammonia is 0.22 to 0.6 L / h; the stirring speed of the reaction is 100 r / min to 600 r / min. A method for preparing a ternary cathode material precursor, characterized by the following.

10. The nickel source contains nickel(II) sulfate, the cobalt source contains cobalt(II) sulfate, the manganese source contains manganese(II) sulfate, the precipitant contains one or more of sodium hydroxide, sodium carbonate, and sodium bicarbonate, and the complexing agent contains one or more of aqueous ammonia, sodium citrate, EDTA, and oxalic acid. The nickel source, the cobalt source, and the manganese source are premixed and used as a ternary metal salt solution. The concentration of the ternary metal salt solution is 100 g / L to 130 g / L. The mixing includes mixing water, a precipitant, and a complexing agent to obtain a reaction base solution, and introducing the ternary metal salt solution, complexing agent, and precipitant into the reaction base solution. The pH of the reaction base solution is 11 to 12. Introduce a protective gas into the reaction system. The method for preparing a ternary cathode material precursor according to Claim 9.

11. In the reaction, the pH of the system is 10 to 12, and the nickel in the supernatant liquid is controlled within the range of 0 to 500 ppm. The temperature of the reaction is 40°C to 70°C. The method for preparing a ternary cathode material precursor according to Claim 9.

12. In the reaction, the pH of the system is gradually decreased from 11.9 to 10.8 to 10.

3. The method for preparing a ternary cathode material precursor according to Claim 9.

13. The raw materials further include a doping element solution. The doping element in the doping element solution contains one or more of Al, Ti, V, W, Zr, Mg, Ce, Nb, and La. The method for preparing a ternary cathode material precursor according to Claim 9.

14. The doping element is W, and the doping element solution contains sodium tungstate and sodium citrate. The mass ratio of the sodium tungstate to the sodium citrate is 1 to 3:

1. The method for preparing a ternary cathode material precursor according to Claim 13.

15. It further includes post-treatment, and the post-treatment includes alkali washing, water washing, and drying. The volume ratio of the alkaline cleaning agent for the alkaline cleaning to the water for the water washing is V 水洗 : V アルカリ洗浄 = (2 to 8): 1 is satisfied, and the temperatures of the alkaline cleaning and the water washing are each 30 to 70 °C, For the drying, the drying temperature is 100°C to 180°C, and the moisture content after drying is made 0.4% or less. The method for preparing a ternary cathode material precursor according to any one of Claims 10 to 14.

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