Submicron grain precursor oxide and preparation method thereof, lithium ion battery positive electrode material and lithium ion battery

Abstract

The invention provides a submicron grain precursor oxide and a preparation method thereof, a lithium ion battery positive electrode material and a lithium ion battery, and relates to the field of lithium battery manufacturing. The preparation method of the submicron grain precursor oxide comprises the following steps: mixing raw materials including a nickel source compound, a cobalt source compound, a manganese source compound and water, and heating to obtain a precursor hot solution; carrying out atomization and pyrolysis treatment on the precursor hot solution to obtain powder particles; carrying out pulpifying washing on the powder particles, and carrying out wet screening, solid-liquid separation and drying to obtain a crude precursor oxide; and carrying out pre-sintering treatment on the rough precursor oxide to obtain the submicron grain precursor oxide. According to the preparation method provided by the invention, the submicron grain precursor oxide powder with low composition segregation and uniform grains can be prepared, and the uniform organization structure is beneficial to improving the electrical properties of the material and can meet the level requirements of the existing industry.

Description

Technical Field

[0001] The present application relates to the field of lithium-ion battery manufacturing, and in particular to a submicron crystal precursor oxide and a preparation method thereof, a lithium-ion battery positive electrode material and a lithium-ion battery. Background Art

[0002] Ternary submicron crystal precursor oxide, in the field of battery material science, mainly refers to a mixed metal oxide with a submicron crystal structure, usually composed of three elements: nickel, cobalt and manganese. This material plays an important role in the manufacture of positive electrode materials for lithium-ion batteries.

[0003] In the traditional preparation process, the ternary precursor prepared by the co-precipitation method has the shortcomings of consuming a large amount of acid and alkali, long reaction time, and high wastewater treatment cost. Therefore, it is urgent to seek new breakthroughs in the preparation method. The spray pyrolysis process has gradually become a current research hotspot due to its advantages such as rapid reaction, low acid and alkali consumption in the preparation process, and no wastewater discharge. In the prior art, the precursor oxide prepared by spray pyrolysis has the disadvantages of wide particle size distribution, significant component segregation, particle crushing, and poor mixed lithium calcination effect, and the precursor solution concentration is low, which greatly increases the energy consumption and cost of water pyrolysis. Therefore, people urgently need to solve the above problems in order to further realize commercialization. Summary of the invention

[0004] The purpose of the present application is to provide a submicron crystal precursor oxide and a preparation method thereof, a lithium ion battery positive electrode material and a lithium ion battery to solve the above problems.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a method for preparing a submicron grain precursor oxide, comprising:

[0007] Mixing raw materials including a nickel source compound, a cobalt source compound, a manganese source compound, and water, and heating to obtain a precursor hot solution;

[0008] atomizing and pyrolyzing the precursor hot solution to obtain powder particles;

[0009] The powder particles are slurried and washed, and a crude precursor oxide is obtained after wet screening, solid-liquid separation (filtration), and drying;

[0010] The crude precursor oxide is pre-sintered to obtain a submicron crystal precursor oxide, which is composed of a single submicron crystal grain or particles with pores connected by a plurality of submicron crystal grains.

[0011] Preferably, in the method for preparing the submicron grain precursor oxide, the nickel source compound includes nickel chloride; the cobalt source compound includes cobalt chloride; and the manganese source compound includes manganese chloride.

[0012] Preferably, the heating is water bath heating, and the temperature of the water bath heating is 30-95°C.

[0013] Preferably, the temperature of the pyrolysis treatment is controlled at 300-1000°C.

[0014] Preferably, the pyrolysis process comprises a feeding section, an evaporation-drying-pyrolysis section, a material forming section and a discharging section;

[0015] Preferably, the temperature of the feeding section is 300-500°C, the temperature of the evaporation-drying-pyrolysis section is 400-700°C, the temperature of the material forming section is 600-1000°C, and the temperature of the discharging section is 1000-400°C.

[0016] Preferably, the slurry washing is performed 1 to 3 times.

[0017] Preferably, the mesh of the wet screening is 300-600 mesh; the sieve under the screen is subjected to solid-liquid separation and drying to obtain a crude precursor oxide.

[0018] Preferably, the pre-firing temperature is 600-900° C., and the pre-firing time is 0.5-3 h.

[0019] Preferably, the oxygen concentration is controlled at 20-50% during the pre-burning.

[0020] In a second aspect, the present application also provides a submicron grain precursor oxide, which is prepared by the above-mentioned submicron grain precursor oxide preparation method.

[0021] Preferably, the particle size of a single grain of the submicron crystal precursor oxide is 100 to 1000 nm, and the powder particle size D 50 =2~8μm, D 100 <50 μm, and the chlorine content in the submicron grain precursor oxide is not higher than 100 ppm.

[0022] In a third aspect, the present application also provides a positive electrode material for a lithium-ion battery, the raw material of which includes the above-mentioned submicron crystal precursor oxide.

[0023] In a fourth aspect, the present application also provides a lithium-ion battery, the raw materials of which include the above-mentioned lithium-ion battery positive electrode material.

[0024] Compared with the prior art, the beneficial effects of this application include:

[0025] The preparation method of the submicron crystal precursor oxide provided by the present application breaks through the limitation that the existing spray pyrolysis process is difficult to achieve the preparation of qualified submicron crystal precursor oxide with high concentration solution, and can prepare submicron precursor oxide powder with low component segregation and uniform grains. The preparation method provided by the present application significantly reduces the energy consumption required for water evaporation and saves costs, while making the precursor oxide yield high.

[0026] The submicron crystal precursor oxide provided in the present application has low spherical component segregation and uniform grains, and the nickel, cobalt and manganese in the precursor are relatively uniformly distributed in space without obvious local enrichment or depletion.

[0027] The lithium-ion battery positive electrode material provided in the present application comprises the above-mentioned submicron crystal precursor oxide as raw material, and the elements in the precursor are evenly distributed, which is conducive to the formation of a uniform organizational structure by lithium mixed calcination. This uniform organizational structure is conducive to improving the electrical performance of the material and can meet the requirements of the existing industry level.

[0028] The lithium-ion battery provided in this application has excellent electrical performance and can meet the requirements of the existing industry level. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0030] Figure 1 is the SEM spectrum of the final precursor oxide product in Example 1;

[0031] Figure 2 is a cross-sectional view of the final precursor oxide product in Example 1;

[0032] Figure 3 is the SEM spectrum of the final precursor oxide product in Example 2;

[0033] Figure 4 is a cross-sectional view of the final precursor oxide product in Example 2;

[0034] Figure 5 This is the XRD pattern of the sample finally obtained in Example 2;

[0035] Figure 6 This is the SEM spectrum of the final precursor oxide product in Example 3;

[0036] Figure 7 is a cross-sectional view of the final precursor oxide product in Example 3;

[0037] Figure 8This is the SEM spectrum of the ternary precursor sample of Comparative Example 1 that was directly pre-fired without slurry washing;

[0038] Fig. 9 This is the SEM spectrum of the ternary precursor sample of Comparative Example 2 with a pre-sintering temperature exceeding 900°C;

[0039] Fig.10 This is the SEM spectrum of the ternary precursor sample pre-fired in comparative example 3 with too low oxygen concentration;

[0040] Fig.11 This is the SEM spectrum of the precursor sample of Comparative Example 4 that was not subjected to wet sieving treatment;

[0041] Fig.12 This is the SEM spectrum of the precursor sample of comparative example 5 subjected to spray pyrolysis without multi-stage temperature control;

[0042] Fig.13 This is the SEM spectrum of the sample in Comparative Example 6 where the atomized powder is not post-treated;

[0043] Fig.14 This is the SEM spectrum of the sample in which the atomized powder in Comparative Example 7 was only subjected to slurry washing and post-treatment;

[0044] Fig.15 This is the SEM spectrum of the sample in Comparative Example 8 where the atomized powder was not pre-calcined. DETAILED DESCRIPTION

[0045] As used herein:

[0046] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0047] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0048] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0049] In these examples, parts and percentages are by mass unless otherwise indicated.

[0050] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0051] “And / or” is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0052] In order to better explain the technical solution provided by this application, before the embodiments, the technical solution is first described as a whole, as follows:

[0053] In a first aspect, the present application provides a method for preparing a submicron grain precursor oxide.

[0054] In an optional embodiment, the preparation method comprises:

[0055] Mixing raw materials including a nickel source compound, a cobalt source compound, a manganese source compound, and water, and heating to obtain a precursor hot solution;

[0056] atomizing and pyrolyzing the precursor hot solution to obtain powder particles;

[0057] The powder particles are slurried and washed, and a crude precursor oxide is obtained after wet screening, solid-liquid separation, and drying;

[0058] The crude precursor oxide is pre-sintered to obtain a submicron crystal precursor oxide.

[0059] In an optional embodiment, the nickel source compound includes nickel chloride; the cobalt source compound includes cobalt chloride; and the manganese source compound includes manganese chloride.

[0060] In an optional embodiment, the usage of the nickel source compound, the cobalt source compound and the manganese source compound can be 6:2:2, 6:1:3, 7:1:2, 8:1:1, or any value between 6:2:2 and 8:1:1 in terms of the atomic fraction ratio of nickel, cobalt and manganese.

[0061] In an optional embodiment, the heating is water bath heating, and the temperature of the water bath heating is 30-95° C. The temperature of the water bath heating can be 30° C., 35° C., 40° C., 45° C., 50° C., 55° C., 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., or any value between 30 and 90° C.

[0062] In an optional embodiment, since the nickel source compound, the cobalt source compound, and the manganese source compound used include chloride salts, the temperature of the pyrolysis treatment is controlled to be 300-1000° C. The temperature of the pyrolysis treatment can be 300° C., 350° C., 400° C., 450° C., 500° C., 550° C., 600° C., 650° C., 700° C., 750° C., 800° C., 850° C., 900° C., 950° C., 1000° C., or any value between 300 and 1000° C.

[0063] In an optional embodiment, the pyrolysis process includes a feeding section, an evaporation-drying-pyrolysis section, a material forming section and a discharging section.

[0064] The temperature of the feeding section is 300-500° C. The temperature of the feeding section can be 300° C., 350° C., 400° C., 450° C., 500° C., or any value between 300-500° C.

[0065] The temperature of the evaporation-drying-pyrolysis stage is 400-700° C. The temperature of the evaporation-drying-heating stage can be 400° C., 450° C., 500° C., 550° C., 600° C., 650° C., or any value between 400-700° C.

[0066] The temperature of the material forming section is 600-1000° C. The temperature of the material forming section can be 600° C., 650° C., 700° C., 750° C., 800° C., 850° C., 900° C., 950° C., 1000° C., or any value between 600-1000° C.

[0067] The temperature of the discharging section is 1000-400° C. The temperature of the discharging section can be 1000° C., 900° C., 800° C., 700° C., 600° C., 500° C., 400° C., or any value between 1000-400° C.

[0068] In an optional embodiment, the slurry washing is performed 1 to 3 times. The slurry washing can be performed 1 time, 2 times, 3 times, or any value between 1 and 3 times.

[0069] In an optional embodiment, the mesh of the wet screening is 300-600 mesh; the sieve is subjected to solid-liquid separation and drying to obtain a crude precursor oxide; the mesh can be 300 mesh, 400 mesh, 500 mesh, 600 mesh, or any value between 300-600 mesh.

[0070] In an optional embodiment, the pre-firing temperature is 600-900° C. The pre-firing temperature may be 600° C., 650° C., 700° C., 750° C., 800° C., 850° C., 900° C., or any value between 600 and 900° C.

[0071] In an optional embodiment, the pre-burning time is 0.5 to 3 hours. The pre-burning time can be 0.5 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, or any value between 0.5 and 3 hours.

[0072] In an optional embodiment, the oxygen concentration is controlled to be 20-50% during the pre-burning. The oxygen temperature can be 20%, 25%, 30%, 35%, 40%, 45%, 50%, or any value between 20% and 50%.

[0073] In a second aspect, the present application also provides a submicron grain precursor oxide, which is prepared by the above-mentioned submicron grain precursor oxide preparation method.

[0074] In an optional embodiment, the submicron crystal precursor oxide has a single grain size of 100 to 1000 nm, and a powder particle size D 50 =2~8μm, D 100 <50μm, and the chlorine content in the submicron crystal precursor oxide is not higher than 100ppm. In the preparation process of the submicron crystal precursor oxide, as the chlorine content in the oxide precursor increases, the structural stability will decrease and the morphology of the positive electrode material will be affected. Too high a chlorine content will cause the grains to agglomerate or form large particles, thereby affecting the performance of the subsequent positive electrode material.

[0075] In a third aspect, the present application also provides a positive electrode material for a lithium-ion battery, the raw material of which includes the above-mentioned submicron crystal precursor oxide.

[0076] In a fourth aspect, the present application also provides a lithium-ion battery, the raw materials of which include the above-mentioned lithium-ion battery positive electrode material.

[0077] The lithium-ion battery provided in this application has excellent electrical performance and can meet the requirements of the existing industry level.

[0078] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0079] Example 1

[0080] This embodiment provides a submicron precursor oxide, a positive electrode material and a lithium ion battery, and the preparation process thereof is as follows:

[0081] Nickel chloride, cobalt chloride and manganese chloride are weighed according to the metal atomic molar ratio of 6:1:3, and a certain proportion of pure water is added. Stir for 4 hours under the condition of heating in a water bath at 65°C until completely dissolved. The total concentration of nickel, cobalt and manganese is 7 mol / L. After forming a uniform hot solution, a feed pump is used to feed the material into the atomizing spray gun. The droplets are evaporated, dried, pyrolyzed and crystallized in the pyrolysis furnace. The program temperatures of the feeding section, evaporation-drying-pyrolysis section, material forming section and discharging section are set to 400°C, 600°C, 1000°C and 500°C respectively. The precursor powder is collected from the discharging section, and the precursor powder is slurried and washed twice with pure water, filtered and dried after passing through a 300-mesh sieve to obtain a crude precursor oxide; the crude precursor oxide is then placed in a high-temperature furnace for reprocessing, and the temperature is selected to be 780°C, the time is 1.5h, and the oxygen concentration is 25% to finally obtain the precursor oxide product. The SEM spectrum of the final precursor oxide product is shown as follows Figure 1 The cross-section of the final precursor oxide product is shown in Figure 2 As shown, the product is uniform spherical submicron particles with good uniformity of particle size distribution; the chlorine content is less than 0.01%.

[0082] The submicron precursor oxide is mixed with lithium and calcined according to a conventional method to obtain a positive electrode material for a lithium-ion battery; the other steps are carried out according to conventional steps to prepare a lithium-ion battery.

[0083] Example 2

[0084] This embodiment provides a submicron precursor oxide, a positive electrode material and a lithium ion battery, and the preparation process thereof is as follows:

[0085] Nickel chloride, cobalt chloride and manganese chloride were weighed according to the metal atomic molar ratio of 6:2:2, and a certain proportion of pure water was added. The mixture was stirred for 4 hours under the condition of heating in a water bath at 60°C until completely dissolved. The total concentration of nickel, cobalt and manganese was 6 mol / L. After a uniform hot solution was formed, a feed pump was used to feed the material into the atomizing spray gun. The droplets were evaporated, dried, pyrolyzed and crystallized in the pyrolysis furnace. The program temperatures of the feeding section, evaporation-drying-pyrolysis section, material forming section and discharging section were set to 400°C, 600°C, 800°C and 400°C respectively. The precursor powder was collected from the discharging section, and the precursor powder was washed 3 times with pure water slurry, filtered and dried after passing through a 400-mesh sieve to obtain a crude precursor oxide; the crude precursor oxide was then placed in a high-temperature furnace for pre-calcination and reprocessing, and the temperature was selected to be 850°C, the time was 1h, and the oxygen concentration was 21%, and finally the precursor oxide product was obtained. The SEM spectrum of the final precursor oxide product is shown as follows Figure 3 The cross-section of the final precursor oxide product is shown in Figure 4 The final XRD pattern of the sample is shown in Figure 5 As shown, the product is uniform spherical nanoparticles with good particle size distribution uniformity; the chlorine content is less than 0.01%.

[0086] The submicron precursor oxide is mixed with lithium and calcined according to a conventional method to obtain a positive electrode material for a lithium-ion battery; the other steps are carried out according to conventional steps to prepare a lithium-ion battery.

[0087] Example 3

[0088] This embodiment provides a submicron precursor oxide, a positive electrode material and a lithium ion battery, and the preparation process thereof is as follows:

[0089] Nickel chloride, cobalt chloride and manganese chloride are weighed according to the metal atomic molar ratio of 8:1:1, and a certain proportion of pure water is added. Stir for 4 hours under the condition of heating in a water bath at 45°C until completely dissolved. The total concentration of nickel, cobalt and manganese is 5 mol / L. After forming a uniform hot solution, a feed pump is used to feed the material into the atomizing spray gun. The droplets are evaporated, dried, pyrolyzed and crystallized in the pyrolysis furnace. The program temperatures are set at 300°C, 500°C, 900°C and 400°C from the feed section to the discharge section. The precursor powder is collected from the discharge section, and the precursor powder is washed once with pure water slurry, filtered and dried after passing through a 500-mesh sieve to obtain a crude precursor oxide; the crude precursor oxide is then placed in a high-temperature furnace for pre-sintering and reprocessing, and the temperature is selected to be 800°C, the time is 1h, and the oxygen concentration is 30% to finally obtain the precursor oxide product. The SEM spectrum of the final precursor oxide product is shown as follows Figure 6The cross-section of the final precursor oxide product is shown in Figure 7 As shown, the product is uniform spherical nanoparticles with good particle size distribution uniformity; the chlorine content is less than 0.01%.

[0090] The submicron precursor oxide is mixed with lithium and calcined according to a conventional method to obtain a positive electrode material for a lithium-ion battery; the other steps are carried out according to conventional steps to prepare a lithium-ion battery.

[0091] Comparative Example 1

[0092] This comparative example provides a submicron precursor oxide, a positive electrode material and a lithium ion battery, and the preparation process thereof is as follows:

[0093] The only difference from Example 1 is that the precursor powder obtained from the discharge end is directly pre-calcined and then processed without slurry washing and wet screening. Figure 8 As shown, it can be seen that the product has obvious large particles and contains more octahedral grains. The particle size uniformity of the precursor powder is significantly reduced compared with embodiment 1; its chlorine content is less than 0.01%.

[0094] The submicron precursor oxide is mixed with lithium and calcined according to a conventional method to obtain a positive electrode material for a lithium-ion battery; the other steps are carried out according to conventional steps to prepare a lithium-ion battery.

[0095] Comparative Example 2

[0096] This comparative example provides a submicron precursor oxide, a positive electrode material and a lithium ion battery, and the preparation process thereof is as follows:

[0097] The only difference from Example 1 is that the pre-sintering and re-treatment temperature is 950°C, and other conditions are the same. Fig. 9 As shown, it can be seen that the product particle size distribution is 1 to 10 μm, but it is basically octahedral grains, and the sphericity of the precursor powder grains is significantly reduced compared with embodiment 1; its chlorine content is less than 0.01%.

[0098] The submicron precursor oxide is mixed with lithium and calcined according to a conventional method to obtain a positive electrode material for a lithium-ion battery; the other steps are carried out according to conventional steps to prepare a lithium-ion battery.

[0099] Comparative Example 3

[0100] This comparative example provides a submicron precursor oxide, a positive electrode material and a lithium ion battery, and the preparation process thereof is as follows:

[0101] The only difference from Example 1 is that no gas is introduced during the pre-burning and reprocessing process, and other conditions are the same. Fig.10As shown, it can be seen that there are obvious octahedral large particles in the 100-nanometer grains in the product, and the overall properties of the precursor powder are significantly reduced compared with implementation 1; its chlorine content is less than 0.01%.

[0102] The submicron precursor oxide is mixed with lithium and calcined according to a conventional method to obtain a positive electrode material for a lithium-ion battery; the other steps are carried out according to conventional steps to prepare a lithium-ion battery.

[0103] Comparative Example 4

[0104] This comparative example provides a submicron precursor oxide, and its preparation process is as follows:

[0105] The difference from Example 1 is that no wet screening treatment is performed, and the other conditions are the same. The SEM spectrum of the obtained sample is as follows Fig.11 As shown, most of the particles are uniform spherical submicron grains, some of the particles are relatively large, and the uniformity of particle size distribution is slightly worse than that of Example 1; and the chlorine content thereof is less than 0.01%.

[0106] The submicron precursor oxide is mixed with lithium and calcined according to a conventional method to obtain a positive electrode material for a lithium-ion battery; the other steps are carried out according to conventional steps to prepare a lithium-ion battery.

[0107] Comparative Example 5

[0108] This comparative example provides a submicron precursor oxide, and its preparation process is as follows:

[0109] The only difference from Example 1 is that a fixed single temperature pyrolysis device is used for pyrolysis during the pyrolysis process, that is, a one-stage pyrolysis is used instead of a multi-stage, temperature gradient method, and the pyrolysis temperature is 1000°C. The SEM spectrum of the obtained sample is as follows: Fig.12 As shown, one part is submicron-sized spherical grains, and the other part is micron-sized octahedral grains. The grain size distribution is uneven and the phase structure is different. The chlorine content is less than 0.01%.

[0110] The submicron precursor oxide is mixed with lithium and calcined according to a conventional method to obtain a positive electrode material for a lithium-ion battery; the other steps are carried out according to conventional steps to prepare a lithium-ion battery.

[0111] Comparative Example 6

[0112] This comparative example provides a submicron precursor oxide, and its preparation process is as follows:

[0113] The difference from Example 1 is that no post-treatment such as pulping washing, wet screening, drying, and pre-calcination was performed. The SEM spectrum of the obtained sample is as follows: Fig.13 As shown, there are basically no submicron grains in the sample; its Cl content is as high as 3-5%.

[0114] The submicron precursor oxide is mixed with lithium and calcined according to a conventional method to obtain a positive electrode material for a lithium-ion battery; the other steps are carried out according to conventional steps to prepare a lithium-ion battery.

[0115] Comparative Example 7

[0116] This comparative example provides a submicron precursor oxide, and its preparation process is as follows:

[0117] The difference from Example 1 is that the atomized powder is only subjected to slurry washing, filtration and drying. The SEM spectrum of the obtained sample is as follows: Fig.14 As shown, the sample has basically no submicron grains and contains some large particles larger than 50 μm; its chlorine content is 0.1-0.5%.

[0118] Comparative Example 8

[0119] This comparative example provides a submicron precursor oxide, and its preparation process is as follows:

[0120] The difference from Example 1 is that the atomized powder is only subjected to slurry washing, wet sieving, filtration and drying. The SEM spectrum of the obtained sample is as follows: Fig.15 As shown, there are basically no submicron grains in the sample; its Cl content is 0.1-0.5%.

[0121] The Cl content and particle size distribution of the precursor oxides prepared by the methods described in Examples 1 to 3 and Comparative Examples 1 to 8 were tested. The test results are shown in Table 1.

[0122] Table 1 Cl content and particle size distribution of precursor oxides

[0123]

[0124]

[0125] Experimental example

[0126] Lithium ion batteries were prepared according to the methods described in Examples 1 to 3 and Comparative Examples 1 to 5, and electrical performance tests were performed on the lithium ion batteries prepared in each Example and Comparative Example. The electrical performance test results are shown in Table 2. The electrical performance of the battery prepared in the Example in the first charge and discharge test was significantly better than that of the comparative example.

[0127] Table 2 Electrical performance test

[0128]

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0130] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing a submicron grain precursor oxide, characterized in that: include: Mixing raw materials including a nickel source compound, a cobalt source compound, a manganese source compound, and water, heating, and stirring to obtain a precursor hot solution; atomizing and pyrolyzing the precursor hot solution to obtain powder particles; The powder particles are slurried and washed, and a crude precursor oxide is obtained after wet screening, solid-liquid separation, and drying; The crude precursor oxide is pre-sintered to obtain a submicron crystal precursor oxide.

2. The method for preparing a submicron grain precursor oxide according to claim 1, characterized in that: The nickel source compound includes nickel chloride; the cobalt source compound includes cobalt chloride; and the manganese source compound includes manganese chloride.

3. The method for preparing a submicron grain precursor oxide according to claim 1, characterized in that: The heating is water bath heating, and the temperature of the water bath heating is 30-95°C.

4. The method for preparing a submicron grain precursor oxide according to claim 1, characterized in that: The temperature of the pyrolysis treatment is controlled to be 300-1000°C.

5. The method for preparing a submicron grain precursor oxide according to claim 4, characterized in that: The pyrolysis process includes a feeding section, an evaporation-drying-pyrolysis section, a material forming section and a discharging section; The temperature of the feeding section is 300-500°C, the temperature of the evaporation-drying-pyrolysis section is 400-700°C, the temperature of the material forming section is 600-1000°C, and the temperature of the discharging section is 1000-400°C.

6. The method for preparing a submicron grain precursor oxide according to any one of claims 1 to 5, characterized in that: Contains one or more of the following conditions: a. The number of times of slurry washing is 1 to 3 times; b. The wet sieve is selected to have a mesh size of 300 to 600; the sieve is subjected to solid-liquid separation and drying to obtain a crude precursor oxide; c. The pre-burning temperature is 600-900° C. and the pre-burning time is 0.5-3 h; d. During the pre-burning, the oxygen concentration is controlled at 20-50%.

7. A submicron grain precursor oxide, characterized in that: The submicron crystal precursor oxide is prepared by the preparation method of any one of claims 1 to 6.

8. The submicron grain precursor oxide according to claim 7, characterized in that: The particle size of a single crystal grain of the submicron crystal precursor oxide is 100 to 1000 nm, and the powder particle size D 50 =2~8μm, D 100 <50μm; the chlorine content in the submicron grain precursor oxide is not higher than 100ppm.

9. A positive electrode material for a lithium ion battery, characterized in that: The raw material comprises the submicron crystal grain precursor oxide as claimed in claim 8.

10. A lithium ion battery, characterized in that: The raw materials include the lithium ion battery positive electrode material as claimed in claim 9.

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