Positive electrode material precursor with high relative true density and preparation method thereof

Abstract

The application provides a positive electrode material precursor with high relative true density and a preparation method thereof, and belongs to the technical field of lithium batteries.The positive electrode material precursor with high relative true density provided by the application is a transition metal oxide or a doped transition metal oxide, and the relative true density p of the positive electrode material precursor satisfies 85%<=p<100%, so that the structural deterioration of the positive electrode material in the cyclic charging and discharging process can be inhibited, and the battery cycle performance can be effectively improved.

Description

Technical Field

[0001] This application belongs to the field of lithium battery technology, and in particular relates to a high relative true density cathode material precursor and its preparation method. Background Technology

[0002] Transition metal oxides or doped transition metal oxide cathode materials are widely used due to their high energy density, making them a focus of attention in battery fabrication. Currently, however, due to limitations in the structural design of cathode material precursors, structural degradation still occurs in cathode materials during charge-discharge cycles, hindering effective improvements in battery cycle performance.

[0003] In view of the above, this application is hereby submitted. Summary of the Invention

[0004] This application provides a high relative true density cathode material precursor and its preparation method, aiming to solve the above-mentioned problems or at least alleviate the defects existing in the prior art.

[0005] The first aspect of this application provides a cathode material precursor with high relative true density. The cathode material precursor is a transition metal oxide or a doped transition metal oxide, and the relative true density ρ of the cathode material precursor is 85%≤ρ<100%.

[0006] The relative true density ρ of the cathode material precursor of this application is 85%≤ρ<100%, which is relatively high. The measured true density of the cathode material precursor is close to the theoretical true density. The closed pore volume inside the precursor is smaller and the skeleton is more compact. After being made into cathode material, the structure is more stable, which helps to suppress the structural degradation of cathode material during cycle charging and discharging and promotes the effective improvement of battery cycle performance.

[0007] In some implementations, the cathode material precursor satisfies at least one of the following conditions: A. The true density ρ of the cathode material precursor, measured using the nitrogen expansion displacement method. 测试 It is 6.0 g / cm³ 3 -6.5g / cm 3 ; B. The particle size D50 of the cathode material precursor is 5μm-30μm, and can be selected as 8μm-30μm; C. The tap density (TD) of the cathode material precursor is 1.8 g / cm³. 3 -2.2g / cm 3 ; D. The particle size distribution of the cathode material precursor, K90 = (D90 - D10) / D50, is 0.1-0.4; E. The cathode material precursor is a nickel-containing transition metal oxide or a doped nickel-containing transition metal oxide.

[0008] In some implementations, the chemical formula of the cathode material precursor is: Ni x Co y Mn z M a O 1+σ ; Where 0.6≤x<1, 0≤y<0.5, 0≤z<0.5, 0≤a<0.1, x+y+z+a=1, 0≤σ<0.34, and M is a doping element.

[0009] In some embodiments, M is selected from at least one of W, Al, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, or Zn.

[0010] A second aspect of this application provides a method for preparing a high relative true density cathode material precursor as described above, comprising: First synthesis reaction stage: A metal salt solution, a complexing agent solution, and a precipitant solution are introduced into a first base liquid containing a precipitant and a complexing agent to carry out the first synthesis reaction, and wet material 1 with the first target particle size is obtained; And / or the second synthesis reaction stage: Based on the raw materials of the first base liquid, wet material 1 is introduced to prepare the second base liquid. Metal salt solution, precipitant solution and complexing agent solution are introduced into the second base liquid to carry out the second synthesis reaction and obtain wet material 2 with the second target particle size. Post-processing stage: The wet material 1 or wet material 2 is subjected to post-processing including sintering to obtain the cathode material precursor.

[0011] In some embodiments, the first synthesis reaction includes a first reaction stage, a second reaction stage, a third reaction stage, and a fourth reaction stage, which are carried out sequentially; wherein, after the first reaction stage begins, the first pH value of the reaction system is controlled to gradually decrease to a second pH value, the second reaction stage maintains the second pH value for the reaction, the third reaction stage raises the pH value of the reaction system to the third pH value to continue the reaction, and the fourth reaction stage raises the pH value of the reaction system to the fourth pH value to continue the reaction until the first target particle size reaches 1μm-4μm; The second synthesis reaction includes: controlling the reaction system to increase from the fifth pH value to the sixth pH value, and continuing the reaction until the second target particle size reaches 5μm-30μm; and controlling the reaction system to gradually increase from the initial complexing agent concentration to the target complexing agent concentration, and continuing the reaction until the second target particle size reaches 5μm-30μm.

[0012] In some embodiments, the sintering process in the post-processing stage includes: gradually increasing the initial sintering temperature of the wet material 2 to the target sintering temperature, and continuing sintering until metal oxides are generated.

[0013] In some embodiments, the post-processing includes washing, dehydration, sintering, sieving, and demagnetization in sequence.

[0014] In some embodiments, the preparation method satisfies at least one of the following conditions: (1) The first, second, third, fourth, fifth, and sixth pH values ​​are each independently controlled within the range of 10.0-12.0. Optionally, the fifth pH value is 10.2-10.6; and optionally, the sixth pH value is 10.8-11.2. (2) The metal salt in the metal salt solution includes nickel, and one or more of the sulfate, nitrate or chloride salts corresponding to at least one of the metal elements cobalt, manganese or M; M is selected from at least one of W, Al, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu or Zn; (3) The precipitant includes one or more of sodium carbonate, sodium hydroxide or potassium hydroxide; (4) The complexing agent includes one or more of ammonia, ammonium carbonate, oxalic acid, citric acid, sodium citrate, ammonium citrate or ammonium oxalate; (5) The concentration of the metal salt in the metal salt solution is 0.5 mol / L-3 mol / L; (6) The mass fraction of the solute in the precipitant solution is 25wt%-45wt%; (7) The mass fraction of the solute in the complexing agent solution is 10wt%-30wt%; (8) The pH value of the first base solution is greater than the pH value of the second base solution; (9) The pH value of the first base solution is 11.3-11.8; (10) The concentration of the complexing agent in the first base solution is 4.0 g / L-8.5 g / L; (11) In the first synthesis reaction, the temperature of the reaction system is controlled at 55℃-65℃; (12) In the first synthesis reaction, the stirring speed of the reaction system is controlled at 600 rpm-1200 rpm; (13) In the first synthesis reaction, the concentration of the complexing agent in the reaction system is controlled to be 4.0 g / L-8.5 g / L; (14) In the first synthesis reaction, the flow rate of the metal salt solution is controlled to be 6.0%-9.0% of the available volume of the reaction vessel; (15) The pH value of the second base solution is 10.0-11.5; (16) The concentration of the complexing agent in the second base solution is 4 g / L-12 g / L; (17) In the second synthesis reaction, the temperature of the reaction system is controlled at 55℃-65℃. (18) In the second synthesis reaction, the stirring speed of the reaction system is controlled at 500 rpm-800 rpm; (19) In the second synthesis reaction, the concentration of the complexing agent in the reaction system is controlled to be 4 g / L-12 g / L; (20) In the second synthesis reaction, the flow rate of the metal salt solution is controlled to be 5.0%-7.8% of the available volume of the reaction vessel; (21) The first and second synthesis reactions are carried out under an inert atmosphere, and the oxygen content of the gas in the first and second synthesis reaction containers is independently controlled to be <1%; (22) In the post-processing stage, the sintering temperature is 500℃-700℃, the sintering heating rate is 2℃ / min-5℃ / min, the sintering atmosphere is nitrogen, and the holding time is 4h-8h.

[0015] A third aspect of this application provides a cathode material, which is prepared using a cathode material precursor with high relative true density as described above.

[0016] A fourth aspect of this application provides a battery, wherein the positive electrode of the battery is made of the positive electrode material as described above.

[0017] A fifth aspect of this application provides an electrical device including a battery as described above.

[0018] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Detailed Implementation

[0019] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0020] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0021] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0022] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0023] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0024] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0025] To address the structural degradation of cathode materials during cyclic charging and discharging, which hinders the improvement of battery cycle performance, this application provides a high relative true density cathode material precursor. The cathode material precursor is a transition metal oxide or a doped transition metal oxide, and the relative true density ρ of the cathode material precursor is 85% ≤ ρ < 100%. By designing a high relative true density cathode material precursor that satisfies 85% ≤ ρ < 100%, the cathode material precursor has fewer closed-cell defects, resulting in better structural integrity of the cathode material after sintering. This effectively suppresses structural degradation during cyclic charging and discharging, thereby improving the battery cycle performance.

[0026] It should be noted that, in the embodiments of this application, the cathode material precursor is a transition metal oxide or a doped transition metal oxide. Exemplarily, the transition metal oxide or doped transition metal oxide may include transition metal oxides such as nickel oxide, nickel cobalt oxide, nickel manganese oxide, and nickel cobalt manganese oxide, or it may include doped transition metal oxides doped with other metal elements (such as W, Al, K, Ca, Sr, Sb, Fe, Cu, Zn, etc.).

[0027] In the embodiments of this application, the tested true density ρ of the cathode material precursor is... 测试 This refers to the density of the cathode material precursor directly measured by the nitrogen expansion displacement method. Nitrogen is used as the test gas, and the sample density is calculated by measuring the volume of gas displaced by the sample. Since test gas molecules cannot enter the closed pores inside the material, the actual material volume calculation includes both the framework volume and the closed pore volume. The calculation formula can be expressed as: ρ 测试 =m / (V1+V2), where m is the mass of the cathode material precursor, V1 is the skeleton volume of the cathode material precursor, and V2 is the closed-cell volume of the cathode material precursor.

[0028] In this embodiment, the relative true density ρ of the cathode material precursor refers to the measured true density ρ of the cathode material precursor. 测试 The theoretical true density ρ of the cathode material precursor 理论 The ratio ρ = ρ 测试 / ρ 理论 In the embodiments of this application, the theoretical true density ρ of the cathode material precursor is... 理论This refers to the mass per unit volume in an absolutely dense state, where "absolutely dense volume" does not include any pores (whether open or closed). The theoretical true density ρ of the cathode material precursor. 理论 The density of a metal can be obtained by calculating the product of the ratio of the molar mass of a single metal element to the total molar mass of all metal elements and the theoretical true density of the metal oxide corresponding to that metal element, and then summing the results. The formula can be expressed as: ρ 理论 = , where c j ρ is the ratio of the molar amount of the j-th metal element in the cathode material precursor to the molar amount of all metal elements. j Let be the theoretical true density of the metal oxide corresponding to the j-th metal element, and n be the total number of metal elements in the cathode material precursor. For example, the cathode material precursor in Example 1 is a nickel-cobalt-manganese oxide (Ni). 0.90 Co 0.06 Mn 0.04 When O, the molar ratio of Ni as the first metallic element to the total metallic elements is 0.90, the molar ratio of Co as the second metallic element to the total metallic elements is 0.06, and the molar ratio of Mn as the second metallic element to the total metallic elements is 0.04. The theoretical true densities ρ1, ρ2, and ρ3 of the corresponding metal oxides NiO, CoO, and MnO are taken as 6.67 g / cm³. 3 6.44 g / cm 3 5.43 g / cm 3 Then the theoretical true density ρ of the cathode material precursor 理论 = =0.90×6.67+0.06×6.44+0.04×5.43=6.6066, the true density ρ is measured. 测试 It is 6.35 g / cm³ 3 Then the relative true density ρ = ρ 测试 / ρ 理论 =6.35÷6.6066=96.12%.

[0029] A higher relative true density ρ indicates that the tested true density is closer to the theoretical true density, the smaller the closed-cell volume inside the precursor, and the denser the framework structure. In the embodiments of this application, the relative true density ρ of the cathode material precursor is 85% ≤ ρ < 100%. Exemplarily, the relative true density ρ of the cathode material precursor can be any relative true density value within the range of 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, ≥85%, ≥86%, ≥87%, ≥88%, ≥89%, ≥90%, ≥91%, ≥92%, ≥93%, ≥94%, ≥95%, ≥96%, ≥97%, ≥98%, ≥99%, or ≥85% and <100%.

[0030] In some embodiments, the test true density ρ of the cathode material precursor is measured using the nitrogen expansion displacement method. 测试 It is 6.0 g / cm³ 3 -6.5g / cm 3 The cathode material precursor has a high measured true density ρ. 测试 This means that the closed-pore volume of the cathode material precursor is smaller, the framework is denser, and the structure is more stable after being made into a cathode material. This helps to reduce side reactions such as gas expansion during cycling and improve the battery's cycle capacity retention. In the embodiments of this application, the true density ρ1 of the cathode material precursor, measured by the nitrogen expansion displacement method, is 6.0 g / cm³. 3 -6.5g / cm 3 For example, the true density ρ of the cathode material precursor is measured. 测试 It can be 6.0 g / cm³ 3 6.1 g / cm 3 6.15 g / cm 3 6.2 g / cm 3 6.25g / cm 3 6.3g / cm 3 6.35g / cm 3 6.4g / cm 3 6.45g / cm 3 6.5g / cm 3 Or 6.0 g / cm 3 -6.5g / cm 3 Any true density value within the range.

[0031] In some embodiments, the particle size D50 of the cathode material precursor is 5μm-30μm. Within this range, the cathode material precursor, after being made into a cathode material, can maintain a high relative true density while improving structural integrity and cycle stability. If the particle size D50 of the cathode material precursor is too small, the precursor is prone to over-burning during sintering, which may lead to an increase in internal closed pores, which is not conducive to improving the relative true density and structural stability of the cathode material. If the particle size D50 is too large, the cathode material is prone to microcracks during charge-discharge cycling, leading to accelerated structural deterioration.

[0032] In this embodiment of the application, the particle size D50 of the cathode material precursor is 5μm-30μm. For example, the particle size D50 of the cathode material precursor can be any particle size D50 value within the range of 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm or 5μm-30μm.

[0033] In some embodiments, the tap density (TD) of the cathode material precursor is 1.8 g / cm³. 3 -2.2g / cm 3 Under the same conditions, fewer closed pores inside the material can also improve the tap density. A high tap density in the cathode material precursor is beneficial for further improving the specific capacity of the sintered cathode material, thereby improving capacity performance. In the embodiments of this application, the tap density TD of the cathode material precursor is 1.8 g / cm³. 3 -2.2g / cm 3 For example, the tap density (TD) of the cathode material precursor can be 1.8 g / cm³. 3 1.85 g / cm 3 1.90 g / cm 3 1.95 g / cm 3 2 g / cm 3 2.05 g / cm 3 2.1 g / cm 3 2.15 g / cm 3 2.2g / cm 3 Or 1.8 g / cm 3 -2.2g / cm 3 Any tap density (TD) value within the range.

[0034] In some embodiments, the particle size distribution K90 = (D90 - D10) / D50 of the cathode material precursor is 0.1-0.4. Within this range, the cathode material precursor has a narrower particle size distribution and better particle size uniformity, which helps to reduce stress concentration and structural deterioration caused by differences in expansion or contraction between particles during charge-discharge cycles, thereby improving the cycle stability of the cathode material. It should be understood that D90, D10, and D50 are the particle size values ​​corresponding to a cumulative volume distribution of 90%, 10%, and 50% for the cathode material precursor, respectively. The smaller the K90 value, the narrower the particle size distribution.

[0035] In this embodiment of the application, the particle size distribution K90=(D90-D10) / D50 of the cathode material precursor is 0.1-0.4. For example, the particle size distribution K90 of the cathode material precursor can be any particle size distribution K90 value in the range of 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4 or 0.1-0.4.

[0036] In some embodiments, the cathode material precursor is a nickel-containing transition metal oxide or a doped nickel-containing transition metal oxide. For example, it can be nickel cobalt manganese oxide, nickel manganese oxide, nickel cobalt oxide, nickel aluminum oxide, nickel cobalt manganese aluminum oxide, or nickel cobalt aluminum oxide. The introduction of nickel into the nickel-containing transition metal oxide or doped nickel-containing transition metal oxide is beneficial to improving the electrochemical performance of the cathode material, enabling the battery to have higher energy density and improve battery capacity performance.

[0037] In some embodiments, the chemical formula of the cathode material precursor is: Ni x Co y Mn z M a O 1+σ ; Where 0.6≤x<1, 0≤y<0.5, 0≤z<0.5, 0≤a<0.1, x+y+z+a=1, 0≤σ<0.34, and M is a doping element.

[0038] In the above chemical formula, x represents the ratio of the molar amount of Ni to the total molar amount of metal elements. The range of x is 0.6 ≤ x < 1. For example, x can be any value in the range of 0.6, 0.63, 0.66, 0.69, 0.7, 0.73, 0.76, 0.79, 0.8, 0.83, 0.86, 0.89, 0.9, 0.93, 0.96, 0.99, 0.999, or 0.6-0.999. The percentage of nickel molar amount in the cathode material precursor to the total molar amount of metal elements is more than 60%, which can promote the cathode material to have higher energy density and improve the battery charge and discharge capacity.

[0039] In the above chemical formula, y represents the ratio of the molar amount of Co to the total molar amount of the metal elements. The range of y is 0 ≤ y < 0.5. For example, y can be any value within the range of 0, 0.03, 0.06, 0.09, 0.1, 0.13, 0.16, 0.19, 0.2, 0.23, 0.26, 0.29, 0.3, 0.33, 0.36, 0.39, 0.4, 0.43, 0.46, 0.49, 0.499, or 0-0.499. Cobalt helps stabilize the material structure, suppresses phase transitions during cycling, and works synergistically with the high relative true density material framework to further improve the structural stability of the cathode material. Simultaneously, cobalt can also improve the capacity performance of the material.

[0040] In the above chemical formula, z represents the ratio of the molar amount of Mn to the total molar amount of the metal elements. The range of z is 0 ≤ y < 0.5. For example, z can be any value in the range of 0, 0.03, 0.06, 0.09, 0.1, 0.13, 0.16, 0.19, 0.2, 0.23, 0.26, 0.29, 0.3, 0.33, 0.36, 0.39, 0.4, 0.43, 0.46, 0.49, 0.499, or 0-0.499. Manganese helps to improve the thermal stability and safety of materials and reduce structural degradation during cycling.

[0041] In the above chemical formula, 'a' represents the ratio of the molar amount of dopant element M to the molar amount of total metal elements. The range of 'a' is 0 ≤ a < 0.1. For example, 'a' can be any value within the range of 0, 0.001, 0.005, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0.099, or 0 ≤ a < 0.1.

[0042] In the above chemical formulas, σ represents the balanced charge of oxygen when the valence state of dopant element M is higher than 2. The range of σ is 0 ≤ σ < 0.2, for example, σ can be 0, 0.001, 0.005, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0. Any value within the range of 10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33 or 0 ≤ σ < 0.34.

[0043] It should be understood that the cathode material precursor in the embodiments of this application can be an undoped nickel-containing transition metal oxide or a doped nickel-containing transition metal oxide, or a doped nickel-containing transition metal oxide or a doped nickel-containing transition metal oxide with doping element M. By appropriately doping, a certain aspect of the cathode material's performance can be enhanced, thereby improving the electrochemical performance of the battery.

[0044] In some embodiments, the dopant element M is selected from at least one of W, Al, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, or Zn.

[0045] To prepare the aforementioned cathode material precursor, another embodiment of this application provides a method for preparing a cathode material precursor with high relative true density, based on an intermittent co-precipitation method. It should be understood that, based on the structural characteristics of the aforementioned cathode material precursor, different combinations of raw materials and reaction pathways can be used to synthesize cathode material precursors with the same key characteristics and performance. Therefore, the preparation method specifically described in this embodiment is merely one exemplary and non-limiting implementation of this application. Any other method capable of preparing a cathode material precursor with the composition, structure, and performance of this application should be considered to fall within the scope of protection sought by this application based on the cathode material precursor product itself.

[0046] Another embodiment of this application provides a method for preparing a high relative true density cathode material precursor, comprising: First synthesis reaction stage: A metal salt solution, a complexing agent solution, and a precipitant solution are introduced into a first base liquid containing a precipitant and a complexing agent to carry out the first synthesis reaction, and wet material 1 with the first target particle size is obtained; Second synthesis reaction stage: Based on the raw materials of the first base liquid, wet material 1 is introduced to prepare the second base liquid. Metal salt solution, precipitant solution and complexing agent solution are introduced into the second base liquid to carry out the second synthesis reaction and obtain wet material 2 with the second target particle size. Post-processing stage: The wet material 2 is subjected to post-processing including sintering to obtain the cathode material precursor.

[0047] In the embodiments of this application, during the first synthesis reaction stage and / or the second synthesis reaction stage, by controlling the pH value and complexing agent concentration of the reaction system, the final cathode material precursor can be made to have a high relative true density ρ of 85%≤ρ<100%.

[0048] In some embodiments, based on the pH change trend, the first synthesis reaction includes a first reaction stage, a second reaction stage, a third reaction stage, and a fourth reaction stage, which are carried out sequentially. Specifically, after the first reaction stage begins, the first pH value of the reaction system is controlled to gradually decrease to a second pH value. In the second reaction stage, the reaction is carried out while maintaining the second pH value. In the third reaction stage, the pH value of the reaction system is increased to a third pH value to continue the reaction. In the fourth reaction stage, the pH value of the reaction system is increased to a fourth pH value to continue the reaction until the first target particle size reaches 1μm-4μm.

[0049] Furthermore, the second synthesis reaction includes: controlling the reaction system to increase from a fifth pH value to a sixth pH value, and continuing the reaction until the second target particle size reaches 5 μm-30 μm; and controlling the reaction system to gradually increase from an initial complexing agent concentration to a target complexing agent concentration, and continuing the reaction until the second target particle size reaches 5 μm-30 μm.

[0050] Thus, by employing a segmented pH control strategy in the first and second synthesis reactions, differentiated deposition environments were achieved at different stages, resulting in cathode material precursors with reduced internal closed-pore defects.

[0051] In some embodiments, the first pH value, the second pH value, the third pH value, the fourth pH value, the fifth pH value, and the sixth pH value are each independently controlled within the range of 10.0-12.0; for example, they can be 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 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 between 10.0 and 12.0.

[0052] Optionally, the fifth pH value is 10.2-10.6; for example, the fifth pH value can be any value between 10.2, 10.3, 10.4, 10.5, 10.6 or 10.2-10.6.

[0053] Optionally, the sixth pH value is 10.8-11.2; for example, the sixth pH value can be any value between 10.8, 10.9, 11.0, 11.1, 11.2 or 10.8-11.2.

[0054] In some embodiments, the metal salt in the metal salt solution includes nickel, and one or more of the sulfate, nitrate or chloride salts corresponding to at least one of the metal elements selected from cobalt, manganese or M; M is selected from at least one of W, Al, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu or Zn.

[0055] For example, the metal salt in the metal salt solution includes one or more of nickel sulfate, nickel nitrate, nickel chloride, cobalt sulfate, cobalt nitrate, cobalt chloride, manganese sulfate, manganese nitrate, or manganese chloride. In addition, when the cathode material precursor has a dopant element M, the metal salt in the metal salt solution also includes sulfate, nitrate, or chloride salts corresponding to at least one of the dopant elements W, Co, Al, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, or Zn, such as titanium sulfate or zinc chloride.

[0056] In some embodiments, the precipitant includes one or more of sodium carbonate, sodium hydroxide, or potassium hydroxide.

[0057] In some embodiments, the complexing agent includes one or more of ammonia, ammonium carbonate, oxalic acid, citric acid, sodium citrate, ammonium citrate, or ammonium oxalate.

[0058] In some embodiments, the concentration of the metal salt in the metal salt solution is 0.5 mol / L to 3 mol / L; exemplaryly, the concentration of the metal salt in the metal salt solution can be any value between 0.5 mol / L, 1.0 mol / L, 1.5 mol / L, 2.0 mol / L, 2.5 mol / L, 3.0 mol / L or 0.5 mol / L to 3 mol / L.

[0059] In some embodiments, the mass fraction of the solute in the precipitant solution is 25wt%-45wt%; exemplaryly, the concentration of the precipitant solution can be 25wt%, 30wt%, 35wt%, 40wt%, 45wt% or any value between these values.

[0060] In some embodiments, the solute mass fraction of the complexing agent solution is 10wt%-30wt%; exemplaryly, the concentration of the complexing agent solution can be any value between 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, or 10wt%-30wt%.

[0061] In some embodiments, the pH value of the first substrate is greater than the pH value of the second substrate.

[0062] In some embodiments, the pH value of the first substrate is 11.3-11.8; exemplaryly, the pH value of the first substrate can be any value between 11.3, 11.4, 11.5, 11.6, 11.7, 11.8 or 11.3-11.8.

[0063] In some embodiments, the complexing agent concentration of the first substrate is 4.0 g / L to 8.5 g / L; exemplaryly, the complexing agent concentration of the first substrate can be any value between 4.0 g / L, 4.5 g / L, 5.0 g / L, 5.5 g / L, 6.0 g / L, 6.5 g / L, 7.0 g / L, 7.5 g / L, 8.0 g / L, 8.5 g / L, or 4.0 g / L to 8.5 g / L.

[0064] In some embodiments, the temperature of the reaction system is controlled at 55°C-65°C in the first synthesis reaction; for example, the temperature of the reaction system in the first synthesis reaction can be any value between 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C or 55°C-65°C.

[0065] In some embodiments, in the first synthesis reaction, the stirring speed of the reaction system is controlled to be 600 rpm-1200 rpm; for example, in the first synthesis reaction, the stirring speed of the reaction system can be any value between 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, 1100 rpm, 1200 rpm or 600 rpm-1200 rpm.

[0066] In some embodiments, in the first synthesis reaction, the concentration of the complexing agent in the reaction system is controlled to be 4.0 g / L-8.5 g / L; exemplaryly, in the first synthesis reaction, the concentration of the complexing agent in the reaction system can be controlled to be any value between 4.0 g / L, 4.5 g / L, 5.0 g / L, 5.5 g / L, 6.0 g / L, 6.5 g / L, 7.0 g / L, 7.5 g / L, 8.0 g / L, 8.5 g / L, or 4.0 g / L-8.5 g. The ammonia concentration mentioned in this application refers to NH4. + Concentration in solution.

[0067] In some embodiments, during the first synthesis reaction, the flow rate of the metal salt solution is controlled to be 6.0% / h-9.0% / h of the available volume of the reaction vessel; exemplaryly, during the first synthesis reaction, the flow rate of the metal salt solution can be any value between 6.0% / h, 6.5% / h, 7.0% / h, 7.5% / h, 8.0% / h, 8.5% / h, 9.0% / h, or 6.0% / h-9.0% / h of the available volume of the reaction vessel.

[0068] In some embodiments, the pH value of the second substrate is 10.0-11.5; exemplaryly, the pH value of the second substrate can be any value between 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11.0, 11.1, 11.2, 11.3, 11.4, 11.5 or 10.0-11.5.

[0069] In some embodiments, the complexing agent concentration of the second substrate is 4 g / L-12 g / L; exemplaryly, the complexing agent concentration of the second substrate can be any value between 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 11 g / L, 12 g / L or 4 g / L-12 g / L.

[0070] In some embodiments, the temperature of the reaction system is controlled at 55°C-65°C in the second synthesis reaction. For example, the temperature of the reaction system in the second synthesis reaction can be any value between 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C or 55°C-65°C.

[0071] In some embodiments, in the second synthesis reaction, the stirring speed of the reaction system is controlled to be 500 rpm-800 rpm; for example, in the second synthesis reaction, the stirring speed of the reaction system can be any value between 500 rpm, 600 rpm, 700 rpm, 800 rpm or 500 rpm-800 rpm.

[0072] In some embodiments, in the second synthesis reaction, the concentration of the complexing agent in the reaction system is controlled to be 4 g / L-12 g / L; exemplaryly, in the second synthesis reaction, the concentration of the complexing agent in the reaction system can be any value between 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 11 g / L, 12 g / L or 4 g / L-12 g / L.

[0073] In some embodiments, in the second synthesis reaction, the flow rate of the metal salt solution is controlled to be 5.0% / h-7.8% / h of the available volume of the reaction vessel; exemplaryly, in the second synthesis reaction, the flow rate of the metal salt solution can be any value between 5.0% / h, 5.5% / h, 6.0% / h, 6.5% / h, 7.0% / h, 7.5% / h, 7.8% / h or 5.0% / h-7.8% / h of the available volume of the reaction vessel.

[0074] Complexing agents can slow down the coprecipitation reaction rate, and the flow rate of the metal salt solution and the precipitant are positively correlated with the coprecipitation rate. By controlling the flow rate of the metal salt solution, the concentration of the complexing agent, and the pH value of the reaction system, the formation rate, morphology, and aggregation of primary particles can be controlled, thereby affecting the pore size inside the secondary particles.

[0075] Temperature affects the coprecipitation reaction rate, which in turn affects the size and number of closed pores within the material. Lower temperatures increase the number of nuclei (forming new primary particles) and decrease the growth rate of primary particles, making it easier to form smaller primary particles. Conversely, higher temperatures result in fewer nuclei (forming new primary particles), a faster growth rate of primary particles, and larger primary particles. Larger primary particles may have fewer internal closed-pore defects.

[0076] Stirring speed can affect the agglomeration of primary particles, as well as the size and number of closed pores within the material. Excessive stirring speed can easily break up agglomerated secondary particles, potentially increasing the number of pores within them. Simultaneously, stirring speed can also affect the local concentration gradient of the raw material, influencing the sedimentation of primary particles.

[0077] In some embodiments, the first synthesis reaction and the second synthesis reaction are carried out under an inert atmosphere, and the oxygen content of the gas in the first synthesis reaction container and the second synthesis reaction container is independently controlled to be <1%. The inert atmosphere (such as nitrogen or argon) can effectively prevent metal ions from being oxidized during the first synthesis reaction and the second synthesis reaction, so as to ensure the phase purity and structural uniformity of the cathode material precursor.

[0078] In some embodiments, the sintering process in the post-processing stage includes: gradually increasing the initial sintering temperature of the wet material 2 to the target sintering temperature, and continuing sintering until metal oxides are formed. By gradually increasing the initial sintering temperature of the wet material 2 to the target sintering temperature, it is beneficial for the material to sequentially complete processes such as desorption of adsorbed water, desorption of crystal water, decomposition of hydroxides, and crystal transformation at different temperature stages, avoiding cracking or closed-cell defects caused by rapid temperature rise leading to excessive particle shrinkage.

[0079] In some embodiments, the post-processing sequentially includes washing, dehydration, sintering, sieving, and demagnetization. The purpose of washing is to remove residual alkali metal ions (such as Na+) from the wet material 2. + ) and anions (such as SO4 ions) 2- The process can be achieved by combining alkaline washing and water washing. For example, alkaline washing can be performed using a dilute alkaline solution (such as NaOH solution) to wash the material, while water washing uses deionized water to further remove residual ions. The purpose of dehydration treatment is to remove most of the free water in the material, reducing the moisture content to a suitable range for sintering. Conventional methods such as centrifugation and pressure filtration can be used, for example.

[0080] In some embodiments, during the post-processing stage, the sintering temperature is 500℃-700℃, the sintering heating rate is 2℃ / min-5℃ / min, the sintering atmosphere is nitrogen, and the holding time is 4h-8h. As a non-limiting example, the sintering temperature can be any value between 500℃, 550℃, 600℃, 650℃, 700℃, or 500℃-700℃. The sintering heating rate can be any value between 2.0℃ / min, 2.5℃ / min, 3.0℃ / min, 3.5℃ / min, 4.0℃ / min, 4.5℃ / min, 5.0℃ / min, or 2℃ / min-5℃ / min. Using a gradual heating method, the heating rate is slower, which can avoid particle cracking or pore structure damage caused by rapid heating.

[0081] The heat preservation time can be any value between 4.0h, 4.5h, 5.0h, 5.5h, 6.0h, 6.5h, 7.0h, 7.5h, 8.0h or 4h-8h.

[0082] Another embodiment of this application provides a cathode material, which is prepared using a cathode material precursor with high relative true density as described above. For example, lithium hydroxide is mixed into the cathode material precursor, and then the lithium-mixed material is sintered in oxygen at 800°C for 15 hours to obtain the cathode material.

[0083] Another embodiment of this application provides a battery, wherein the positive electrode of the battery is made of the positive electrode material as described above.

[0084] Another embodiment of this application provides an electrical device, including the battery as described above.

[0085] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all reagents and raw materials used in the embodiments are commercially available or synthesized by conventional methods, and the instruments used in the embodiments are also commercially available.

[0086] Example 1 A high relative true density cathode material precursor is provided, and its preparation method is as follows: Solution preparation: Weigh battery-grade nickel sulfate, cobalt sulfate, and manganese sulfate according to the molar ratio Ni:Co:Mn=90:6:4, and add water to prepare a 2 mol / L metal salt solution; prepare a sodium hydroxide solution with a solute mass fraction of 32.5 wt% and an ammonia solution with a solute mass fraction of 20 wt%.

[0087] First synthesis reaction stage: Pure water, sodium hydroxide solution and ammonia water are added to the reaction vessel as the first base liquid. The pH value of the first base liquid is 11.6, the ammonia concentration is 6.0 g / L, and the temperature is 60℃. A metal salt solution, sodium hydroxide solution, and ammonia water were simultaneously introduced into a reactor for the first synthesis reaction. During the reaction, the flow rate of the metal salt solution was controlled at 7.5%-8.0% of the reactor volume per hour. After the first synthesis reaction began, the pH value was gradually decreased from 11.6 to 11.0. In the second reaction stage, the pH value was maintained at 11.0. In the third reaction stage, the pH value was increased to 11.2. In the fourth stage, the pH value was increased to 11.5 and maintained until a wet material 1 with an average particle size D50 of approximately 3.5 μm was produced. During the first synthesis reaction, nitrogen protection was maintained to keep the oxygen content <1%. The stirring speed was 900 rpm, the reaction temperature was 60℃, and the ammonia concentration was 4.4 g / L-4.6 g / L.

[0088] Second synthesis reaction stage: Pure water, wet material 1, sodium hydroxide solution and ammonia water are added to the reaction vessel to prepare the second base solution. The pH value of the second base solution is 10.4, the ammonia concentration is 5.0 g / L, and the temperature is 55℃. The metal salt solution, sodium hydroxide solution, and ammonia water were fed into the reactor in a parallel flow to carry out the second synthesis reaction. During the reaction, the flow rate of the metal salt solution was controlled to be 5.5%-5.8% of the reactor volume. The pH of the reaction system was controlled to increase from the fifth pH value of 10.4 to the sixth pH value of 11.0, and then the sixth pH value was maintained until a wet material 2 with an average particle size D50 of about 14.0 μm was obtained. During the second synthesis reaction, nitrogen protection was provided to maintain an oxygen content of <1%, the stirring speed was 1000 rpm, the reaction temperature was 60℃, and the ammonia concentration was 9.0 g / L.

[0089] Post-processing stage: The wet material 2 is washed with liquid alkali and pure water, then dehydrated. The washed and dehydrated nickel cobalt manganese hydroxide wet material is put into a box-type muffle furnace for sintering at 600℃. The heating rate from room temperature to the target sintering temperature is 3℃ / min. Nitrogen protection is used throughout the process, and the holding time is 6h. The finished material is sieved and demagnetized to obtain the cathode material precursor.

[0090] Example 2 A high relative true density cathode material precursor is provided, and the preparation method differs from that in Example 1 as follows: First synthesis reaction stage: The pH of the first base solution is reduced to 11.4, and the ammonia concentration of the first base solution is increased to 6.5 g / L; The first pH in the first stage of the synthesis reaction was controlled at 11.4, and the ammonia concentration was 6.5 g / L.

[0091] Other reaction conditions remained the same as in Example 1.

[0092] Example 3 A high relative true density cathode material precursor is provided, and the preparation method differs from that in Example 1 as follows: Second synthesis reaction stage: The flow rate of the metal salt solution added in the second synthesis reaction stage is controlled to be 6.5% / h-6.8% / h.

[0093] Other reaction conditions remained the same as in Example 1.

[0094] Example 4 A high relative true density cathode material precursor is provided, and the preparation method differs from that in Example 1 as follows: Solution preparation: Adjust the proportion of metal salt solution ingredients. Weigh battery-grade nickel sulfate, cobalt sulfate, manganese sulfate and zirconium sulfate according to the molar ratio of Ni:Co:Mn:Zr=82:5:12:1, and add water to prepare a 2 mol / L metal salt solution.

[0095] Other reaction conditions remained the same as in Example 1.

[0096] Example 5 A high relative true density cathode material precursor is provided, and the preparation method differs from that in Example 1 as follows: First synthesis reaction stage: The pH value of the first base solution is 11.8, and the ammonia concentration of the first base solution is 5.0 g / L; In the first reaction stage, the flow rate of the added metal salt solution was controlled to be 7.5%-8.0% of the reactor volume. The first pH value was controlled to gradually decrease from 11.8 to 11.5. There were no third or fourth pH values. The first synthesis reaction temperature was 65℃. The particle size of wet material 1 was about 3.7μm. There is no second synthesis reaction stage; Other reaction conditions remained the same as in Example 1.

[0097] Example 6 A high relative true density cathode material precursor is provided, and the preparation method differs from that in Example 1 as follows: First synthesis reaction stage: The pH of the first base solution is 11.4, and the ammonia concentration of the first base solution is 6.5 g / L; The first pH in the first stage of the synthesis reaction was controlled at 11.4, and the ammonia concentration was 6.5 g / L.

[0098] Second synthesis reaction stage: The flow rate of the metal salt solution added in the second synthesis reaction stage is controlled at 7.5% / h-8.0% / h, and the sixth pH value is 10.0.

[0099] Other reaction conditions remained the same as in Example 1.

[0100] Example 7 A high relative true density cathode material precursor is provided, and the preparation method differs from that in Example 1 as follows: First synthesis reaction stage: The pH of the first base solution is 11.3, and the ammonia concentration of the first base solution is 7.5 g / L; The flow rate of the metal salt solution added in the first synthesis reaction stage was controlled to be 8.5% / h-9.0% / h, the first pH was 11.3, the ammonia concentration was 7.5 g / L, and the particle size of wet material 1 was about 10.5 μm.

[0101] There is no second synthesis reaction stage.

[0102] Other reaction conditions remained the same as in Example 1.

[0103] Comparative Example 1 A high relative true density cathode material precursor is provided, and the preparation method differs from that in Example 1 as follows: First synthesis reaction stage: The pH of the first base solution is 11.7, and the ammonia concentration of the first base solution is 10.0 g / L; The pH was controlled at 11.7, the ammonia concentration at 10.0 g / L, and the stirring speed at 1200 rpm during the first synthesis reaction stage.

[0104] There is no second synthesis reaction stage.

[0105] Other reaction conditions remained the same as in Example 1.

[0106] Comparative Example 2 A high relative true density cathode material precursor is provided, and the preparation method differs from that in Example 1 as follows: First synthesis reaction stage: only the first pH value is 11.6 and the second pH value is 11.0, there is no third pH value and fourth pH value. The stirring speed is controlled at 1200 rpm, the ammonia concentration is 4.5 g / L, and the particle size of wet material 1 is about 3.0 μm.

[0107] No second synthesis reaction stage: Controlling the second synthesis reaction stage.

[0108] Other reaction conditions remained the same as in Example 1.

[0109] Comparative Example 3 A high relative true density cathode material precursor is provided, and the preparation method differs from that in Example 1 as follows: First synthesis reaction stage: The flow rate of the metal salt solution added in the first synthesis reaction stage is controlled at 8.0% / h-8.4% / h, and the ammonia concentration is 4.5g / L.

[0110] Second synthesis reaction stage: The flow rate of the metal salt solution added in the second synthesis reaction stage is controlled to be 6.5% / h-6.9% / h.

[0111] Other reaction conditions remained the same as in Example 1.

[0112] Physicochemical analysis D50, D10, and D90: Measured using a laser particle size analyzer (Mastersizer 3000) in accordance with the national standard GB / T 19077-2016 Particle Size Analysis by Laser Diffraction; k90 = (D90 - D10) / D50; TD (Tap Density): Measured using a powder tap density tester (model: Dandong Baite BT-302), in accordance with the national standard GB / T 5162-2021 "Determination of Tap Density of Metal Powders"; Contents of nickel, cobalt, manganese, tungsten, molybdenum, niobium, zirconium, titanium, and antimony: determined by inductively coupled plasma mass spectrometry (Instrument model: Agilent 7850 ICP-MS), in accordance with the national standard GB / T 8647.11-2019 Chemical analysis methods for nickel - Part 11: Determination of the contents of magnesium, aluminum, manganese, cobalt, copper, zinc, cadmium, tin, antimony, lead, and bismuth by inductively coupled plasma mass spectrometry.

[0113] True density was tested using the nitrogen expansion displacement method. The testing instrument was a BSD-TD1 true density meter, and the testing conditions were high-purity helium gas at a pressure of 0.34 ± 0.02 MPa.

[0114] Table 1. Statistical Table of Physicochemical Data of Cathode Material Precursor To verify the performance advantages of the cathode material precursors prepared in each embodiment and comparative example, cathode materials were prepared using the cathode material precursors prepared in each embodiment and comparative example. The preparation process of each cathode material is as follows: The cathode material precursors prepared in each embodiment and comparative example were mixed with lithium hydroxide. The molar ratio of Li:(Ni+Co+Mn) in the lithium-mixed material was 1.05:1. Then, the lithium-mixed material was sintered in oxygen to form a polycrystalline cathode material.

[0115] Furthermore, the cathode materials prepared from the cathode material precursors of each embodiment and comparative example were assembled into button-type half-cells for electrochemical performance testing. The preparation process of the button-type half-cells is as follows: The positive electrode materials obtained from the positive electrode material precursors of the above embodiments and comparative examples were mixed with conductive acetylene black and polytetrafluoroethylene (PVDF) binder (prepared as an 8wt% PVDF / NMP solution) at a mass ratio of 8:1:1. The mixture was then coated onto aluminum foil to form a positive electrode sheet. The negative electrode sheet was a lithium metal sheet, and the electrolyte was a 1mol / L LiPF6 / EC:DMC solution (volume ratio 1:1). The battery casing, positive and negative electrode sheets, separator (Celgard-2325), spring sheet, gasket, and electrolyte were assembled into a CR-2032 type half cell in a vacuum glove box.

[0116] The electrochemical performance of each CR-2032 half-cell was tested using the Blue Electric testing system. Specifically, charge-discharge tests were conducted at room temperature with both ambient and high voltage (2.8-4.3V for ambient voltage and 3.0-4.5V for high voltage). The discharge capacity at 0.1C current under ambient voltage, the capacity retention after 100 cycles at 1C current under ambient voltage, and the capacity retention after 100 cycles at 1C current under high voltage were all measured. 1C = 210 mAh / g. The test results are summarized in Table 2 below. Table 2. Statistical Table of Electrochemical Data for Cathode Materials Performance Analysis: The cathode material precursors provided in Examples 1-7 of this application have a relative true density of 85%≤ρ<100%, fewer closed-cell defects, better structural integrity of the cathode material after sintering, and effective suppression of structural degradation during cyclic charging and discharging, thereby improving the cycle performance of the battery.

[0117] The technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification, provided that such combination does not contain contradictions.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A high relative true density cathode material precursor, characterized in that, The cathode material precursor is a transition metal oxide or a doped transition metal oxide, and the relative true density ρ of the cathode material precursor is 85% ≤ ρ < 100%.

2. The cathode material precursor according to claim 1, characterized in that, At least one of the following conditions must be met: A. The true density ρ of the cathode material precursor, measured using the nitrogen expansion displacement method. 测试 It is 6.0 g / cm³ 3 -6.5g / cm 3 ; B. The particle size D50 of the cathode material precursor is 5μm-30μm, and can be selected as 8μm-30μm; C. The tap density TD of the cathode material precursor is 1.8 g / cm³. 3 -2.2g / cm 3 ; D. The particle size distribution K90=(D90-D10) / D50 of the cathode material precursor is 0.1-0.4; E. The cathode material precursor is a nickel-containing transition metal oxide or a doped nickel-containing transition metal oxide.

3. The cathode material precursor according to claim 1 or 2, characterized in that, The chemical formula of the cathode material precursor is: Ni x Co y Mr z M a O 1+σ ; Where 0.6≤x<1, 0≤y<0.5, 0≤z<0.5, 0≤a<0.1, x+y+z+a=1, 0≤σ<0.34, and M is a doping element; Optionally, M is selected from at least one of W, Al, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, or Zn.

4. A method for preparing a high relative true density cathode material precursor as described in any one of claims 1 to 3, characterized in that, include: First synthesis reaction stage: A metal salt solution, a complexing agent solution, and a precipitant solution are introduced into a first base liquid containing a precipitant and a complexing agent to carry out the first synthesis reaction, and wet material 1 with the first target particle size is obtained; And / or the second synthesis reaction stage: Based on the raw materials of the first base liquid, the wet material 1 is introduced to prepare the second base liquid, and the metal salt solution, the precipitant solution and the complexing agent solution are introduced into the second base liquid to carry out the second synthesis reaction, so as to obtain the wet material 2 with the second target particle size; Post-processing stage: The wet material 1 or the wet material 2 is subjected to post-processing including sintering to obtain the cathode material precursor.

5. The method for preparing the cathode material precursor according to claim 4, characterized in that, The first synthesis reaction includes a first reaction stage, a second reaction stage, a third reaction stage, and a fourth reaction stage, which proceed sequentially. In the first reaction stage, after the reaction begins, the first pH value of the reaction system is gradually decreased to a second pH value. In the second reaction stage, the second pH value is maintained for the reaction. In the third reaction stage, the pH value of the reaction system is increased to a third pH value to continue the reaction. In the fourth reaction stage, the pH value of the reaction system is increased to a fourth pH value to continue the reaction until the first target particle size reaches 1 μm-4 μm. The second synthesis reaction includes: controlling the reaction system to increase from a fifth pH value to a sixth pH value, and continuing the reaction until the second target particle size reaches 5 μm-30 μm; and controlling the reaction system to gradually increase from an initial complexing agent concentration to a target complexing agent concentration, and continuing the reaction until the second target particle size reaches 5 μm-30 μm.

6. The method for preparing the cathode material precursor according to claim 4, characterized in that, In the post-processing stage, the sintering process includes: gradually raising the initial sintering temperature of the wet material 2 to the target sintering temperature, and continuing sintering until metal oxides are generated; Optionally, the post-processing includes washing, dehydration, sintering, sieving, and demagnetization in sequence.

7. The method for preparing the cathode material precursor according to claim 5, characterized in that, The preparation method satisfies at least one of the following conditions: (1) The first pH value, the second pH value, the third pH value, the fourth pH value, the fifth pH value, and the sixth pH value are each independently controlled within the range of 10.0-12.0; (2) The metal salt in the metal salt solution includes nickel, and one or more of the sulfate, nitrate or chloride salts corresponding to at least one of the metal elements cobalt, manganese or M; M is selected from at least one of W, Al, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu or Zn; (3) The precipitant includes one or more of sodium carbonate, sodium hydroxide, or potassium hydroxide; (4) The complexing agent includes one or more of ammonia, ammonium carbonate, oxalic acid, citric acid, sodium citrate, ammonium citrate or ammonium oxalate; (5) The concentration of the metal salt in the metal salt solution is 0.5 mol / L-3 mol / L; (6) The mass fraction of the solute in the precipitant solution is 25wt%-45wt%; (7) The solute mass fraction of the complexing agent solution is 10wt%-30wt%; (8) The pH value of the first base solution is greater than the pH value of the second base solution; (9) The pH value of the first base solution is 11.3-11.8; (10) The concentration of the complexing agent in the first base liquid is 4.0 g / L-8.5 g / L; (11) In the first synthesis reaction, the temperature of the reaction system is controlled at 55℃-65℃; (12) In the first synthesis reaction, the stirring speed of the reaction system is controlled to be 600 rpm-1200 rpm; (13) In the first synthesis reaction, the concentration of the complexing agent in the reaction system is controlled to be 4.0 g / L-8.5 g / L; (14) In the first synthesis reaction, the flow rate of the metal salt solution is controlled to be 6.0%-9.0% of the available volume of the reaction vessel; (15) The pH value of the second base solution is 10.0-11.5; (16) The concentration of the complexing agent in the second base liquid is 4 g / L-12 g / L; (17) In the second synthesis reaction, the temperature of the reaction system is controlled at 55℃-65℃. (18) In the second synthesis reaction, the stirring speed of the reaction system is controlled to be 500 rpm-800 rpm; (19) In the second synthesis reaction, the concentration of the complexing agent in the reaction system is controlled to be 4 g / L-12 g / L; (20) In the second synthesis reaction, the flow rate of the metal salt solution is controlled to be 5.0%-7.8% of the available volume of the reaction vessel; (21) The first synthesis reaction and the second synthesis reaction are carried out under an inert atmosphere, and the oxygen content of the gas in the first synthesis reaction vessel and the second synthesis reaction vessel is independently controlled to be <1%; (22) In the post-processing stage, the sintering temperature is 500℃-700℃, the sintering heating rate is 2℃ / min-5℃ / min, the sintering atmosphere is nitrogen, and the holding time is 4h-8h.

8. A positive electrode material, characterized in that, The cathode material is prepared using a high relative true density cathode material precursor as described in any one of claims 1-3 or as described in any one of claims 4-7.

9. A battery, characterized in that, The positive electrode of the battery is made of the positive electrode material as described in claim 8.

10. An electrical-related device, characterized in that, Includes the battery as described in claim 10.

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