Order-to-disorder transformed spinel phase lithium nickel manganese oxide material, preparation method therefor and use thereof

Abstract

An order-to-disorder transformed spinel phase lithium nickel manganese oxide material, a preparation method therefor and a use thereof. A matrix of the spinel phase lithium nickel manganese oxide material is primarily based on an ordered spinel phase, but the surface of the matrix is a surface layer primarily based on a disordered spinel phase. Moreover, there is also a doping element for increasing the degree of disorder and / or promoting single crystallization in the matrix. By introducing the doping element, the content of trivalent manganese in the matrix is increased, so that the internal degree of disorder is increased on the basis of the ordered spinel phase; moreover, single crystal particles of the order-to-disorder transformed spinel phase lithium nickel manganese oxide material are at the micron level, and said material has a small specific surface area and excellent capacity. The surface layer primarily based on the disordered spinel phase can further improve the capacity, cycle performance and rate capability of the order-to-disorder transformed spinel phase lithium nickel manganese oxide material, so that said material has great advantages in subsequent material coating. The order-to-disorder transformed spinel phase lithium nickel manganese oxide material can be widely used in preparation of lithium battery positive electrodes.

Description

Disordered transition spinel phase lithium nickel manganese oxide material and preparation method and application thereof Technical Field

[0001] The present disclosure relates to the technical field of positive electrode materials, and in particular to a disordered spinel phase lithium nickel manganese oxide material and a preparation method and application thereof. Background Art

[0002] Spinel phase lithium nickel manganese oxide (LiNixMn 2-x O4, x = 0.40-0.55) is a lithium battery positive electrode with an ultra-high platform voltage (4.7V), a theoretical capacity of 147mAh / g, and an energy density ≥650Wh / kg. In general, the Ni:Mn ratio in the spinel phase of lithium nickel manganese oxide is 1:3, and Li:(Ni+Mn) = 0.5, which can effectively reduce the cost of materials. From the perspective of energy density and cost, this material has great market potential, and many companies have set this material as a future development target. Lithium nickel manganese oxide, like its predecessor lithium manganese oxide, has a spinel structure and a very stable thermochemical structure. However, in terms of cyclic storage of lithium nickel manganese oxide, especially when used in high-temperature environments, the Mn element is very easy to dissolve, resulting in structural failure, which is also the main problem hindering its commercial use.

[0003] Research on lithium nickel manganese oxide spinel has been ongoing for over 20 years, but the mechanism of Mn dissolution remains uncertain. The mainstream view is that different valence states of Mn dissolve via different pathways. However, recent literature and experimental results indicate that disordered spinel exhibits superior cycling performance.

[0004] Based on the valence ratio of the Mn element, spinels are classified into ordered (P4332) and disordered (Fd3m) types. In the former, the Mn element is theoretically tetravalent, resulting in an ordered arrangement of transition metal ions. However, in the latter, due to the presence of oxygen vacancies and, consequently, a certain amount of trivalent manganese, the transition metal ions are no longer ordered but disordered. The ion diffusion rate in this disordered structure is two orders of magnitude higher than that in the ordered structure, resulting in higher capacity and rate performance. Conventional high-temperature sintering processes produce oxygen vacancies, which, while producing some disordered phases, also produce some rock salt phase LiNixOy. The resulting rock salt phase LiNixOy loses electrochemical activity. By adjusting the ordered (P4332) and disordered (Fd3m) configurations of the spinel, the capacity and rate performance of spinel-phase lithium nickel manganese oxide can be improved. Adjusting the trivalent manganese content can achieve this by adjusting the disordered spinel content, but how to adjust the trivalent manganese content remains an unresolved issue.

[0005] In view of this, the present disclosure is proposed.

[0006] Summary of the Invention

[0007] The purpose of the present disclosure includes providing a disordered spinel phase lithium nickel manganese oxide material, which controls the content of trivalent manganese by doping a lithium nickel manganese oxide matrix dominated by an ordered spinel phase and introducing a disordered spinel phase on the surface to improve the capacity, cycle and rate performance.

[0008] The purpose of the present disclosure includes providing a preparation method of disordered spinel phase lithium nickel manganese oxide material, which adjusts the content of trivalent manganese in the material by doping and surface thermal reduction to improve capacity, cycle and rate performance.

[0009] The purpose of the present disclosure includes providing an application of a disordered spinel phase lithium nickel manganese oxide material in preparing a positive electrode of a lithium battery.

[0010] The present disclosure also aims to provide a lithium-ion battery.

[0011] In order to achieve at least one of the above-mentioned objectives of the present disclosure, the following technical solutions may be adopted:

[0012] In the first aspect, the present disclosure provides a disordered transformed spinel phase lithium nickel manganese oxide material, which includes: a lithium nickel manganese oxide matrix mainly composed of an ordered spinel phase and a surface layer mainly composed of a disordered spinel phase formed on at least a portion of the surface of the matrix, wherein the matrix contains doping elements that increase disorder and / or promote single crystallization.

[0013] In some embodiments of the present disclosure, the content of trivalent manganese in the matrix is ​​5%-20%, and the content of trivalent manganese in the surface layer is 30%-50%.

[0014] In some embodiments of the present disclosure, the doping element includes at least one of Mg, Al, P, Fe, Ti, W, Mo, Nb, Y, and Zr.

[0015] In some embodiments of the present disclosure, the doping element that increases disorder includes at least one of Al, P, and Mo; and the doping element that promotes single crystallization includes at least one of Nb and Mo.

[0016] In some embodiments of the present disclosure, the mass of the surface layer accounts for 5%-30% of the disordered spinel phase lithium nickel manganese oxide material.

[0017] In some embodiments of the present disclosure, the particle size of the disordered spinel phase lithium nickel manganese oxide material is 4 μm-6 μm.

[0018] In some embodiments of the present disclosure, the thickness of the surface layer is 100 nm-500 nm.

[0019] In a second aspect, the present disclosure provides a method for preparing a disordered spinel phase lithium nickel manganese oxide material, comprising:

[0020] calcining a mixture containing nickel, manganese, lithium and a dopant, cooling the mixture after calcination, and annealing the mixture at the same temperature to obtain a sintered material;

[0021] The sintered material is mixed with a reducing agent to perform surface thermal reduction to increase the content of trivalent manganese on the surface of the sintered material;

[0022] The oxygen content of the first atmosphere is more than twice the oxygen content of the second atmosphere.

[0023] In some embodiments of the present disclosure, the doping element in the dopant includes at least one of Mg, Al, P, Fe, Ti, W, Mo, Nb, Y and Zr.

[0024] In some embodiments of the present disclosure, the content of each dopant is 1000 ppm-5000 ppm.

[0025] In some embodiments of the present disclosure, the mass of the reducing agent is 0.5%-5% of the mass of the sintering material.

[0026] In some embodiments of the present disclosure, the reducing agent comprises a carbon source.

[0027] In some embodiments of the present disclosure, the carbon source includes at least one of glucose, sucrose, PEG, phenolic resin, and resorcinol-formaldehyde resin.

[0028] In some embodiments of the present disclosure, the calcination and the holding annealing are both performed in the first atmosphere, and the oxygen partial pressure of the first atmosphere is greater than or equal to 70%.

[0029] In some embodiments of the present disclosure, the oxygen partial pressure of the second atmosphere is less than or equal to 30%.

[0030] In some embodiments of the present disclosure, the second atmosphere is at least one of hydrogen and carbon monoxide.

[0031] In some embodiments of the present disclosure, the calcination temperature is 800° C.-1000° C., and the calcination time is 10 h-20 h.

[0032] In some embodiments of the present disclosure, the temperature of the heat preservation annealing is 600-700° C., and the annealing time is 5 h-10 h.

[0033] In some embodiments of the present disclosure, the surface thermal reduction temperature is 300-600° C., and the calcination time is 1-5 h.

[0034] In some embodiments of the present disclosure, before mixing the sintering material and the reducing agent, the process further includes crushing the sintering material.

[0035] In some embodiments of the present disclosure, the crushing includes first performing coarse crushing using a crushing roller and then performing graded crushing using an air flow crusher.

[0036] In some embodiments of the present disclosure, the crushing rollers are two opposite each other with a gap of 0.1 mm to 0.3 mm. The particles coarsely crushed by the crushing rollers have a Dv10 of 4 μm to 6 μm, a Dv50 of 7 μm to 12 μm, and a Dv90 of 20 μm to 25 μm.

[0037] In some embodiments of the present disclosure, the pneumatic crushing performs graded crushing to produce particles with a Dv10 of 1-2 μm, a Dv50 of 4 μm-8 μm, and a Dv90 of 8 μm-20 μm.

[0038] In some embodiments of the present disclosure, the nickel and manganese in the mixture are provided in the form of a nickel-manganese compound precursor, and the preparation method of the nickel-manganese compound precursor includes: preparing a nickel source and a manganese source into a transition metal solution; then adding an excess of a precipitant to the transition metal solution to react, cooling, filtering, washing, and drying to obtain the nickel-manganese compound precursor.

[0039] In some embodiments of the present disclosure, the molar ratio of nickel to manganese in the nickel source and the manganese source is 1:3.

[0040] In some embodiments of the present disclosure, the manganese source includes at least one of manganese hydroxide, manganese sulfate, manganese carbonate, and manganese acetate.

[0041] In some embodiments of the present disclosure, the nickel source includes at least one of nickel hydroxide, nickel sulfate, nickel carbonate, and nickel acetate.

[0042] In some embodiments of the present disclosure, the lithium is provided by a lithium source, and the lithium source includes one or more of lithium hydroxide, lithium carbonate, lithium sulfate, and lithium acetate, with a purity greater than 98%.

[0043] In some embodiments of the present disclosure, the molar ratio of lithium to nickel and manganese in the lithium source and the nickel and manganese compound precursor is 0.48-0.55:1.

[0044] In a third aspect, the present disclosure provides the use of the disordered spinel phase lithium nickel manganese oxide material described in the above embodiment in preparing a positive electrode of a lithium battery.

[0045] In a fourth aspect, the present disclosure provides a lithium-ion battery comprising a positive electrode sheet, a negative electrode sheet, a separator spaced between the positive electrode sheet and the negative electrode sheet, and an electrolyte, wherein the positive electrode sheet contains the disordered transformed spinel phase lithium nickel manganese oxide material described in the above embodiment.

[0046] Compared with the prior art, the advantages of the present invention include:

[0047] The present disclosure provides a disordered spinel phase lithium nickel manganese oxide material, whose matrix is ​​mainly an ordered spinel phase, but the surface of the matrix is ​​a surface layer mainly composed of a disordered spinel phase, and there are doping elements in the matrix that increase disorder and / or promote single crystallization. By introducing doping elements, the trivalent manganese content in the matrix is ​​increased, thereby increasing the internal disorder on the basis of the ordered spinel phase, and making the single crystal particles of the disordered spinel phase lithium nickel manganese oxide material at the micron level, with a small specific surface area and excellent capacity. The surface layer mainly composed of a disordered spinel phase can further improve the capacity, cycle and rate performance of the disordered spinel phase lithium nickel manganese oxide material, and has great advantages in subsequent material coating. The disordered spinel phase lithium nickel manganese oxide material can be widely used in the preparation of lithium battery positive electrodes.

[0048] The present disclosure also provides a method for preparing a disordered spinel phase lithium nickel manganese oxide material, which is prepared by adding a dopant to the mixture before calcining the mixture. The addition of the dopant can change the content of trivalent manganese in the sintered material and promote the single crystallization of the sintered material. By changing the content of trivalent manganese in the sintered material, the disorder degree can be adjusted on the basis of a matrix mainly composed of an ordered spinel phase, and the effect of promoting single crystallization can make the single crystal particles of the obtained material at the micron level, with a small specific surface area and excellent capacity. Furthermore, the present disclosure can induce the tetravalent manganese on the surface of the sintered material as the matrix to be converted into trivalent manganese through surface thermal reduction, increase the content of trivalent manganese, and fully convert the surface layer of the material into disordered spinel, constructing a thin layer of disordered phase on the surface. Through the method of dopants and surface thermal reduction, the present disclosure can not only increase the disorder and morphology of the system, but also improve the capacity, cycle and rate performance of the disordered spinel phase lithium nickel manganese oxide material. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0050] FIG1 is a SEM morphology image of Example 1 provided in the present disclosure;

[0051] FIG2 is an XRD diffraction pattern of Example 1 provided in the present disclosure;

[0052] FIG3 is a SEM morphology image of Example 5 provided in the present disclosure;

[0053] FIG4 is an XRD diffraction pattern of Example 5 provided in the present disclosure;

[0054] FIG5 is a graph showing the first charge and discharge curves of Example 1 and Comparative Example 2 provided in the present disclosure. DETAILED DESCRIPTION

[0055] The embodiments of the present disclosure will be described in detail below with reference to the examples. However, those skilled in the art will appreciate that the following examples are intended only to illustrate the present disclosure and should not be construed as limiting the scope of the present disclosure. Where specific conditions are not specified in the examples, the experiments were performed under conventional conditions or the conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, all are commercially available conventional products.

[0056] The endpoints of the ranges and any values ​​disclosed in this disclosure are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0057] The present disclosure provides a disordered spinel phase lithium nickel manganese oxide material, which includes: a lithium nickel manganese oxide matrix mainly composed of an ordered spinel phase and a surface layer mainly composed of a disordered spinel phase formed on at least a portion of the surface of the matrix.

[0058] The surface layer in the present disclosure is not intended to achieve coating of the substrate, but to introduce a disordered spinel phase on the surface of the substrate, thereby improving the cycle performance.

[0059] Since spinel is divided into two types: ordered (P4332) and disordered (Fd3m). The Mn element in the ordered spinel phase is theoretically tetravalent, and the transition metals are arranged in order; while the disordered spinel phase contains a certain amount of trivalent manganese because it contains a certain amount of oxygen defects, and the transition metal ions are no longer regular but mixed. In the present disclosure, "lithium nickel manganese oxide matrix with an ordered spinel phase as the main component" generally refers to the proportion of the ordered spinel phase in the matrix being greater than 90%. Similarly, "the surface layer with a disordered spinel phase as the main component" generally refers to the proportion of the disordered spinel phase in the surface layer being greater than 50%. Specifically, the ratio of the ordered spinel phase to the disordered spinel phase in the matrix is ​​≥0.9. The ratio of the ordered spinel phase to the disordered spinel phase in the surface layer is ≤0.5. The content of trivalent manganese in the matrix is ​​about 5%-20%, and the content of trivalent manganese in the surface layer is about 30%-50%.

[0060] In the present disclosure, the mass of the surface layer accounts for about 5%-30% of the disordered spinel phase lithium nickel manganese oxide material. The particle size of the disordered spinel phase lithium nickel manganese oxide material is 4-6 μm, and the thickness of the surface layer is about 100nm-500nm.

[0061] The present disclosure provides a method for preparing a disordered spinel phase lithium nickel manganese oxide material, which comprises the following steps:

[0062] S1. Calcination.

[0063] A mixture containing nickel, manganese, lithium and a dopant is calcined at 800-1000°C for 10-20 hours. After calcination, the mixture is cooled to 600-700°C and annealed for 5-10 hours to obtain a sintered material.

[0064] In the present disclosure, the nickel, manganese, and lithium in the mixture can be derived from a nickel source, a manganese source, and a lithium source, respectively, or the nickel and manganese can be provided simultaneously by a nickel-manganese compound precursor. The nickel-manganese compound precursor is preferably a hydroxide. The method for preparing the nickel-manganese compound precursor in the present disclosure comprises: preparing a transition metal solution by combining a nickel source and a manganese source in a molar ratio of 1:3; then adding an excess precipitant to the transition metal solution, reacting at a set temperature, cooling, filtering, washing, and drying to obtain the nickel-manganese compound precursor.

[0065] The manganese source includes, but is not limited to, at least one of manganese hydroxide, manganese sulfate, manganese carbonate, and manganese acetate; the nickel source includes, but is not limited to, at least one of nickel hydroxide, nickel sulfate, nickel carbonate, and nickel acetate; and the lithium source includes, but is not limited to, one or more of lithium hydroxide, lithium carbonate, lithium sulfate, and lithium acetate, with a purity greater than 98%. The molar ratio of lithium to nickel-manganese in the lithium source and the nickel-manganese compound precursor is 0.48-0.55:1. In certain embodiments, the molar ratio of lithium to nickel-manganese in the lithium source and the nickel-manganese compound precursor can be, for example, any one of 0.48:1, 0.5:1, 0.51:1, 0.52:1, 0.55:1, or a range between any two of these.

[0066] The doping element of the dopant includes, but is not limited to, at least one of Mg, Al, P, Fe, Ti, W, Mo, Nb, Y, and Zr. The content of each dopant is 1000 ppm to 5000 ppm. In certain embodiments, the content of each dopant is, for example, any one of 1000 ppm, 2000 ppm, 3000 ppm, 4000 ppm, 5000 ppm, or a range between any two of them.

[0067] In the present disclosure, by adding a dopant into the mixture and calcining it together with nickel, manganese and lithium, the addition of the dopant can make the interior and surface of the sintered material contain a certain amount of trivalent manganese, which is beneficial to improving the capacity and cycle performance.

[0068] Regarding the doping of combined elements, the ratio needs to be adjusted according to the elements and the expected effects. For example, after Al is doped, it will diffuse into the entire system due to its smaller ionic radius, so Al is a bulk dopant. Since the valence state of aluminum is +3, it will affect the surrounding manganese to a certain extent when replacing Ni, increasing the trivalent manganese content and the disordered content. The introduction of P has multiple effects. First, the atomic radius of P is significantly larger than that of Al. The entry of P will help improve the overall ion diffusion rate, and the multivalent P element will further increase the trivalent manganese content on the surface. In addition, the presence of P has been proven to increase the proportion of the (100) plane, and there are more Li channels on the (100) plane, making the capacity of the truncated spinel easier to play. On the basis of Al-P, a high-valent metal element can also be selected. Among them, Nb and Mo elements are the most valuable. Nb has similar effects to P, such as improving rate performance and capacity, but it will reduce the trivalent manganese content. In addition, Nb will increase the surface free energy, so the system will tend to reduce the specific surface area. This accelerates the formation of large single crystals from small particles, promoting single crystal formation. Among various rare metals, Nb is present in the Earth's crust at a very high concentration, far exceeding Ag. Choosing Nb is a reasonable option for cost considerations. If you don't want to reduce the trivalent manganese content, you can use Mo, which also promotes large single crystal formation. However, unlike Nb, Mo increases the trivalent manganese content. On a matrix that is as ordered as possible, various dopants are used to increase disorder.

[0069] Furthermore, in the present disclosure, calcination and heat preservation annealing are both carried out under the first atmosphere, and the oxygen partial pressure of the first atmosphere is greater than or equal to 70%. Due to the thermodynamic characteristics of the high-temperature calcination of spinel, oxygen will leave the lattice and produce oxygen defects. While obtaining some disordered phases, some rock salt phases LiNixOy are produced, and this part loses electrochemical activity. In the present disclosure, it tends to obtain spinels dominated by ordered phases, with fewer rock salt phases of ordered structures, and the 4.7V platform will be longer and more stable. Therefore, in order to reduce the generation of oxygen defects, the present disclosure performs calcination in a high oxygen-containing atmosphere. And in the process of heat preservation annealing, the first atmosphere is also continuously replenished. At this time, oxygen will further supplement oxygen, so that the disordered spinel content of the sintered material is reduced, and a spinel dominated by an ordered phase is formed.

[0070] In other embodiments of the present disclosure, the calcination temperature may be, for example, any one of 800° C., 850° C., 900° C., 950° C., and 1000° C., or a range between any two thereof, and the calcination time may be, for example, any one of 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, and 20 h, or a range between any two thereof. The annealing temperature may be, for example, any one of 600° C., 610° C., 650° C., 680° C., and 700° C., or a range between any two thereof, and the annealing time may be, for example, any one of 5 h, 6 h, 7 h, 8 h, 9 h, and 10 h, or a range between any two thereof.

[0071] S2. Crushing the sintered material.

[0072] Crushing involves coarse crushing using crushing rollers, followed by graded crushing using air flow crushing. The crushing rollers are opposed to each other, with a gap of 0.1mm-0.3mm. Coarse crushing with the crushing rollers produces particles with a Dv10 of 4μm-6μm, a Dv50 of 7μm-12μm, and a Dv90 of 20μm-25μm. Graded crushing with air flow crushing produces particles with a Dv10 of 1μm-2μm, a Dv50 of 4μm-8μm, and a Dv90 of 8μm-20μm.

[0073] In the present disclosure, crushing the sintered material is beneficial for dispersing the sintered material to form dispersed large-particle single crystals, which is more conducive to capacity utilization, improves the compaction density to a certain extent, and makes the battery energy density higher.

[0074] S3. Surface thermal reduction.

[0075] The crushed sintered material is mixed with a reducing agent and subjected to surface thermal reduction at 300-600°C for 1-5 hours to increase the content of trivalent manganese on the surface of the sintered material.

[0076] In the present disclosure, the surface trivalent manganese content can be increased by reducing the surface of the sintered material. The surface thermal reduction in the present disclosure is carried out in a second atmosphere with a lower oxygen partial pressure. The surface thermal reduction can induce the tetravalent manganese on the surface of the sintered material to be converted into trivalent manganese, so that the surface layer of the material can be fully converted into disordered spinel, and a thin layer of disordered phase on the surface can be constructed, so that the cycle performance can be further improved. However, an overly reducing environment may reduce the metal element, so it is necessary to ensure the ratio of oxidizing and reducing components in the reduction process, which is mainly adjusted by reducing agent and atmosphere control. Specifically, the mass of the reducing agent in the present disclosure is 0.5%-5% of the mass of the sintered material, the oxygen partial pressure of the second atmosphere is less than or equal to 30%, and the second atmosphere is at least one of hydrogen and carbon monoxide, thereby effectively controlling the surface reduction degree of the sintered material and then controlling the surface trivalent manganese content. In the present disclosure, the reducing agent is excessive, wherein part of the reducing agent thermally reduces the surface of the sintered material, and the excess reducing agent will be converted into gas by reacting with oxygen in the atmosphere, or directly decomposed to leave the surface phase. The purpose of this is to ensure that the reducing environment is not too strong, so as to avoid reducing the metal element and destroying the structure.

[0077] In the present disclosure, the reducing agent includes but is not limited to a carbon source or other reagents having a similar reducing effect. The carbon source includes but is not limited to at least one of glucose, sucrose, PEG, phenolic resin and resorcinol-formaldehyde resin.

[0078] In other embodiments of the present disclosure, the percentage of the mass of the reducing agent to the mass of the sintered material can be, for example, any one of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or a range between any two of them. The temperature of the surface thermal reduction can be, for example, any one of 300° C., 350° C., 400° C., 450° C., 500° C., 550° C., or 600° C., or a range between any two of them. The time of the surface thermal reduction can be, for example, any one of 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours, or a range between any two of them.

[0079] The present invention forms a spinel dominated by an ordered phase by supplementing oxygen during the calcination and annealing stages, and simultaneously utilizes dopants for doping and cooperates with thermal reduction on the surface of the sintered material to effectively control the content of trivalent manganese. By introducing a certain amount of disordered spinel, not only the capacity can be increased, but also the cycle and rate performance can be improved.

[0080] The above-mentioned disordered spinel-phase lithium nickel manganese oxide material provided by the present disclosure can be widely used in the preparation of lithium battery positive electrodes. Correspondingly, the present disclosure also provides a lithium-ion battery comprising a positive electrode sheet, a negative electrode sheet, a separator spaced between the positive electrode sheet and the negative electrode sheet, and an electrolyte, wherein the positive electrode sheet contains the above-mentioned disordered spinel-phase lithium nickel manganese oxide material.

[0081] The technical solution of the present disclosure is further described below in conjunction with specific implementation methods.

[0082] Example 1

[0083] This embodiment provides a disordered spinel phase lithium nickel manganese oxide material, and the preparation method thereof includes the following steps:

[0084] (1) Preparation of nickel manganese hydroxide.

[0085] A transition metal mixed solution is prepared using manganese sulfate and nickel sulfate sources, with a nickel-manganese ion molar ratio of (1-1.05):(3-3.1). Sodium hydroxide is added to the continuously stirred transition metal mixed solution as a precipitant to control the pH. The precipitated nickel-manganese compound is filtered, washed, and dried to produce a nickel-manganese hydroxide precursor.

[0086] (2) Take 3 kg of prepared nickel manganese hydroxide, in which the Ni:Mn content is 1:3. According to the molar ratio of lithium to transition metal Li:Me=0.53, lithium carbonate is used as the lithium source, aluminum phosphate and niobium pentoxide (Nb2O5) are added as dopants, and the addition amounts of aluminum phosphate and niobium pentoxide are 4000ppm and 5000ppm respectively. The above raw materials are fully mixed in a high-speed mixer at a speed of 1500rmp, and the mixed material is sintered at 950℃ in a box furnace for 10 hours. Then the temperature is lowered to 650℃ and annealed for 6 hours, and excess oxygen is introduced during the whole process. After annealing, the temperature is naturally lowered to room temperature to obtain a sintered nickel manganese spinel material.

[0087] (3) The sintered nickel-manganese spinel material is subjected to coarse crushing by a rotary wheel and a pair of rollers, with the gap parameter of the rollers being 0.15 mm, to obtain coarsely crushed material. The coarsely crushed material has a Dv10 of 4 μm-6 μm, a Dv50 of 7 μm-12 μm, and a Dv90 of 20 μm-25 μm. The coarsely crushed material is further crushed by a jet mill crushing equipment. The crushing pressure is 3-5 atmospheres. The grading parameters are adjusted so that the Dv50 of the discharge material reaches 4 μm-8 μm. The crushed material is sieved to obtain finely crushed spinel.

[0088] (4) Finely crushed spinel as a matrix and carbon source phenolic resin powder were mixed in a high-speed mixer at 1500 rpm, with the mass of the phenolic resin being 1.5% of the mass of the finely crushed spinel. After mixing, the mixture was subjected to surface thermal reduction at 650°C in a low-oxygen atmosphere (less than 20%) for 1 hour to form a surface layer. The resulting product, a disordered spinel-phase lithium nickel manganese oxide material, was removed from the furnace.

[0089] The morphology under a scanning electron microscope is shown in Figure 1, and its XRD diffraction pattern is shown in Figure 2. As can be seen from Figures 1 and 2, the particle size of the disordered spinel phase lithium nickel manganese oxide material is 4-6μm, mainly large octahedral particles, with exposed faces mainly (111) and (100), accompanied by a small amount of (110) crystal face. The content of trivalent manganese in the matrix is ​​about 10.2%, and the content of trivalent manganese in the surface layer is about 39.5%. The mass of the surface layer accounts for about 20.8% of the mass of the disordered spinel phase lithium nickel manganese oxide material, and the thickness of the surface layer is about 300nm.

[0090] Example 2

[0091] This embodiment provides a disordered spinel phase lithium nickel manganese oxide material, and the preparation method thereof includes the following steps:

[0092] (1) Preparation of nickel manganese hydroxide.

[0093] A transition metal mixed solution is prepared using manganese sulfate and nickel sulfate sources, with a nickel-manganese ion molar ratio of (1-1.05):(3-3.1). Sodium hydroxide is added to the continuously stirred transition metal mixed solution as a precipitant to control the pH. The precipitated nickel-manganese compound is filtered, washed, and dried to produce a nickel-manganese hydroxide precursor.

[0094] (2) Take 3 kg of prepared nickel manganese hydroxide, in which the Ni:Mn content is 1:3. According to the molar ratio of lithium to transition metal Li:Me=0.53, lithium carbonate is used as the lithium source, aluminum phosphate and niobium pentoxide are added as dopants, and the addition amounts of aluminum phosphate and niobium pentoxide are 4000ppm and 5000ppm respectively. The above raw materials are fully mixed in a high-speed mixer at a speed of 1500rmp, and the mixed material is sintered at 800℃ in a box furnace for 20h. Then the temperature is lowered to 600℃ and annealed for 10h, and excess oxygen is introduced during the whole process. After annealing, the temperature is naturally lowered to room temperature to obtain a sintered nickel manganese spinel material.

[0095] (3) The sintered nickel-manganese spinel material is subjected to coarse crushing by a rotary wheel and a pair of rollers, with the gap parameter of the rollers being 0.1 mm, to obtain coarsely crushed material. The coarsely crushed material has a Dv10 of 4 μm-6 μm, a Dv50 of 7 μm-12 μm, and a Dv90 of 20 μm-25 μm. The coarsely crushed material is further crushed by a jet mill crushing equipment. The crushing pressure is 3-5 atmospheres. The grading parameters are adjusted so that the Dv50 of the discharge material reaches 4 μm-8 μm. The crushed material is sieved to obtain finely crushed spinel.

[0096] (4) Finely crushed spinel as a matrix and carbon source phenolic resin powder were mixed in a high-speed mixer at 1500 rpm, with the mass of the phenolic resin being 0.5% of the mass of the finely crushed spinel. After mixing, the mixture was subjected to surface thermal reduction at 300°C in a low-oxygen atmosphere (less than 20%) for 5 hours to form a surface layer, and then removed from the furnace to obtain the finished product - a disordered spinel phase lithium nickel manganese oxide material.

[0097] Example 3

[0098] This embodiment provides a disordered spinel phase lithium nickel manganese oxide material, and the preparation method thereof includes the following steps:

[0099] (1) Preparation of nickel manganese hydroxide.

[0100] A transition metal mixed solution is prepared using manganese sulfate and nickel sulfate sources, with a nickel-manganese ion molar ratio of (1-1.05):(3-3.1). Sodium hydroxide is added to the continuously stirred transition metal mixed solution as a precipitant to control the pH. The precipitated nickel-manganese compound is filtered, washed, and dried to produce a nickel-manganese hydroxide precursor.

[0101] (2) Take 3 kg of prepared nickel manganese hydroxide, in which the Ni:Mn content is 1:3. According to the molar ratio of lithium to transition metal Li:Me=0.53, lithium carbonate is used as the lithium source, and aluminum phosphate and niobium pentoxide are added as dopants. The addition amount of aluminum phosphate and niobium pentoxide is 4000ppm and 5000ppm respectively. The above raw materials are fully mixed in a high-speed mixer at a speed of 1500rmp, and the mixed material is sintered at 1000℃ in a box furnace for 12h. Then the temperature is lowered to 700℃ and annealed for 5h, and excess oxygen is introduced during the whole process. After annealing, the temperature is naturally lowered to room temperature to obtain a sintered nickel manganese spinel material.

[0102] (3) The sintered nickel-manganese spinel material is subjected to coarse crushing by a rotary wheel and a pair of rollers, with the gap parameter of the rollers being 0.3 mm, to obtain coarsely crushed material. The coarsely crushed material has a Dv10 of 4 μm-6 μm, a Dv50 of 7 μm-12 μm, and a Dv90 of 20 μm-25 μm. The coarsely crushed material is further crushed by a jet mill crushing equipment. The crushing pressure is 3-5 atmospheres. The grading parameters are adjusted so that the Dv50 of the discharge material reaches 4 μm-8 μm. The crushed material is sieved to obtain finely crushed spinel.

[0103] (4) Finely crushed spinel as a matrix and phenolic resin powder as a carbon source were mixed in a high-speed mixer at 1500 rpm, with the mass of the phenolic resin being 5% of the mass of the finely crushed spinel. After mixing, the mixture was subjected to surface thermal reduction at 600°C in a low-oxygen atmosphere (less than 20%) for 2 hours to form a surface layer, and then removed from the furnace to obtain the finished product - a disordered spinel phase lithium nickel manganese oxide material.

[0104] Example 4

[0105] This embodiment is basically the same as Example 1, except that, in this embodiment, the reducing agent carbon source phenolic resin powder in Example 1 is replaced by sucrose.

[0106] Example 5

[0107] This embodiment is substantially the same as embodiment 1, except that in this embodiment, niobium pentoxide in embodiment 1 is replaced with molybdenum trioxide Mo. Its morphology is shown in FIG3 , and its XRD diffraction pattern is shown in FIG4 .

[0108] Comparative Example 1

[0109] This comparative example is basically the same as Example 1, except that in this comparative example, no dopant is used in step (2), and the surface thermal reduction in step (4) is not performed.

[0110] Comparative Example 2

[0111] This comparative example is basically the same as Example 1, except that the surface thermal reduction in step (4) is not performed in this comparative example.

[0112] Comparative Example 3

[0113] This comparative example is substantially the same as Example 1, except that the aluminum phosphate in step (2) of Example 1 is omitted in this comparative example.

[0114] Comparative Example 4

[0115] This comparative example is basically the same as Example 1, except that no dopant is used in step (2) of this comparative example, that is, the aluminum phosphate and high-valent element Nb in step (2) of Example 1 are omitted.

[0116] Comparative Example 5

[0117] This comparative example is basically the same as Example 1, except that in this comparative example, the surface thermal reduction in step (4) is performed using an oxygen atmosphere.

[0118] Comparative Example 6

[0119] This comparative example is basically the same as Example 1, except that in this comparative example, the sintering process in step (2) uses an air atmosphere, and there is no annealing process and step (4).

[0120] Comparative Example 7

[0121] This comparative example is basically the same as Example 1, except that the step (3) of further pulverizing the coarse material using a jet mill pulverizing device is omitted in this comparative example.

[0122] Comparative Example 8

[0123] This comparative example is basically the same as Example 1, except that the amount of the reducing agent used in this comparative example is 10% of the mass of the finely crushed spinel.

[0124] Comparative Example 9

[0125] This comparative example is basically the same as Example 1, except that in this comparative example, the reducing agent is replaced by carbon fiber and aluminum powder, and the added amount of carbon fiber is 2% carbon fiber and 3% aluminum powder.

[0126] Experimental Example: Performance Comparison

[0127] The LiNi obtained in the examples and comparative examples 0.5 Mn 1.5 The distribution of O4 cathode material was measured by laser particle size analyzer. In order to further verify the electrochemical performance, the LiNi 0.5 Mn 1.5 A button-type half-cell was made by combining O4 positive electrode material with metal lithium negative electrode, and the initial charge and discharge capacity was tested. 0.5 Mn 1.5 A button-type full battery was made using the O4 positive electrode material and commercial graphite negative electrode. The battery was tested for 50 cycles at 45°C from 3.0 to 4.9V and the capacity retention rate was tested.

[0128] It can be seen that Examples 1, 4-5, using the process provided by this disclosure, have capacities greater than 136 mAh / g, and after 50 cycles at 45°C, the residual capacity is greater than 102 mAh / g, with a high-temperature cycle retention rate greater than 83%. Since Examples 2 and 3 only changed the parameters in the preparation process, the disordered spinel phase lithium nickel manganese oxide materials obtained therefrom are similar to those in Example 1, and the test results are also similar, so they are not shown in the above table.

[0129] Among them, it can be seen from the comparison of Example 1 and Example 4 that Example 4 uses sucrose as a carbon source, and the effect is not as good as the resin material of Example 1, because the carbonization temperature of sucrose is lower, and sugar is more easily decomposed and oxidized to leave the surface, and it is easy to form a carbon coating. The purpose of the present disclosure is not to form a carbon coating, but to convert the tetravalent manganese on the surface of the substrate into a trivalent manganese in a low-oxygen environment to construct a thin layer of disordered phase on the surface. Example 5 shows the subtle difference between high-valent elements. Further comparison shows that the trivalent manganese content in Example 5 is higher, which is also caused by the difference between Mo and Nb. But in general, the embodiments are all structures in which the overall ordered spinel is dominant and disorder plays an auxiliary role. Through doping and surface reduction, the high cycle of disordered spinel and the high capacity of ordered spinel are fully utilized.

[0130] A comparison between Example 1 and Comparative Example 1 shows that Comparative Example 1, without doping or surface reduction, exhibits a simple ordered polycrystalline morphology. This morphology exhibits superior capacity, but very poor cycling performance, significantly inferior to that of Example 1 of the present disclosure.

[0131] In Comparative Example 2, no surface thermal reduction was performed. It can be seen that the retention rate is slightly lower than that of Example 1, and the BET is significantly improved, indicating that the disordered spinel on the surface is beneficial for reducing side reactions. To illustrate the difference after surface oxidation, Figure 5 shows the comparison of the half-charge first charge and discharge curves of Example 1 and Comparative Example 2 at 0.1C, respectively. It can be seen that the effect of Example 1 is better than that of Comparative Example 2.

[0132] Comparative Example 3 is not doped with Al and P elements, and its capacity is low, and its bulk disorder is lower than that of Example 1. Through surface oxidation, its cycling performance is not bad, but it is obviously not as good as Example 1.

[0133] Comparative Example 4, without any dopant, showed no large particles under SEM. The lack of doping to regulate the system resulted in lower capacity during full cycling, and transition metals were easily leached. Surface oxidation improved cycling performance somewhat, but did not address the low capacity. After 50 cycles, only 89 mAh / g remained.

[0134] Comparative Example 5 uses an oxygen atmosphere in the surface oxidation step, which causes the surface reducing agent to be rapidly oxidized by oxygen, and the oxygen will replenish oxygen to the surface layer, resulting in a decrease in the content of disordered spinel on the surface and poor cycle performance.

[0135] Comparative Example 6 does not use a high oxygen content atmosphere to fill the high-temperature oxygen deficiency during calcination, but directly uses air to increase the disorder degree, then a spinel with a very high disorder degree will be prepared, and the large disordered particles grow slowly, and the Dv50 is significantly lower than that of the embodiment. The trivalent manganese content of this disordered spinel is very high and the content is not well controlled. In the charge and discharge test, the 4V trivalent manganese discharge platform of Comparative Example 6 is much higher than that of the embodiment, and in the X-ray diffraction pattern (XRD), the rock salt phase peak corresponding to the 43-degree angle is significantly increased, which is why its capacity is not as good as that of the embodiment. In addition, the capacity decay in the full electric cycle is faster than that of Example 1, which also shows that excessive disorder is not necessarily conducive to circulation.

[0136] Comparative Example 7 did not use air flow crushing and classification, and its capacity was not as good as that of the example. SEM observations showed that the large particles were clumped together, not single large particles, resulting in a Dv50 of 12.07. This morphology is not conducive to the subsequent utilization of the coating modified material.

[0137] In Comparative Example 8, the amount of reducing agent used is too large. Although the reducing property is not much in the oxygen atmosphere, the subsequent ineffective reducing agent remains on the surface, affecting the capacity, and the discharge and initial efficiency are both low.

[0138] Comparative Example 9 used a strong reducing agent. Although the reducing power was not very high in the presence of oxygen, it still damaged the spinel structure, causing a process phenomenon during the first charge. Impurities generated by the reduction exacerbated the high-temperature cycling side reactions, causing a rapid drop in cycling performance.

[0139] In summary, the present disclosure provides a disordered spinel phase lithium nickel manganese oxide material, whose matrix is ​​mainly an ordered spinel phase, but the surface of the matrix is ​​a surface layer mainly composed of a disordered spinel phase, and there are doping elements in the matrix that increase the disorder and / or promote single crystallization. By introducing doping elements, the trivalent manganese content in the matrix is ​​increased, thereby increasing the internal disorder on the basis of the ordered spinel phase, and making the single crystal particles of the disordered spinel phase lithium nickel manganese oxide material at the micron level, with a small specific surface area and excellent capacity. The surface layer mainly composed of a disordered spinel phase can further improve the capacity, cycle and rate performance of the disordered spinel phase lithium nickel manganese oxide material, and has great advantages in subsequent material coating. The disordered spinel phase lithium nickel manganese oxide material can be widely used in the preparation of lithium battery positive electrodes. The present disclosure also provides a method for preparing a disordered spinel phase lithium nickel manganese oxide material, which is prepared by adding a dopant to the mixture before calcining the mixture. The addition of the dopant can change the content of trivalent manganese in the sintered material and promote the single crystallization of the sintered material. By changing the content of trivalent manganese in the sintered material, the disorder degree can be adjusted on the basis of a matrix mainly composed of an ordered spinel phase, and the effect of promoting single crystallization can make the single crystal particles of the obtained material at the micron level, with a small specific surface area and excellent capacity. Furthermore, the present disclosure can induce the tetravalent manganese on the surface of the sintered material as the matrix to be converted into trivalent manganese through surface thermal reduction, increase the content of trivalent manganese, and fully convert the surface layer of the material into disordered spinel, constructing a thin layer of disordered phase on the surface. Through the method of dopants and surface thermal reduction, the present disclosure can not only increase the disorder and morphology of the system, but also improve the capacity, cycle and rate performance of the disordered spinel phase lithium nickel manganese oxide material.

[0140] The above describes in detail the optional embodiments of the present disclosure, but the present disclosure is not limited thereto. Within the technical concept of the present disclosure, various simple variations of the technical solution of the present disclosure can be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as the contents disclosed by the present disclosure and fall within the scope of protection of the present disclosure. Industrial Applicability

[0141] The present disclosure provides a disordered spinel phase lithium nickel manganese oxide material, whose matrix is ​​mainly an ordered spinel phase, but the surface of the matrix is ​​a surface layer mainly composed of a disordered spinel phase, and there are doping elements in the matrix that increase disorder and / or promote single crystallization. By introducing doping elements, the trivalent manganese content in the matrix is ​​increased, thereby increasing the internal disorder on the basis of the ordered spinel phase, and making the single crystal particles of the disordered spinel phase lithium nickel manganese oxide material at the micron level, with a small specific surface area and excellent capacity. The surface layer mainly composed of a disordered spinel phase can further improve the capacity, cycle and rate performance of the disordered spinel phase lithium nickel manganese oxide material, and has great advantages in subsequent material coating. The disordered spinel phase lithium nickel manganese oxide material can be widely used in the preparation of lithium battery positive electrodes. The present disclosure also provides a method for preparing a disordered spinel phase lithium nickel manganese oxide material, which is prepared by adding a dopant to the mixture before calcining the mixture. The addition of the dopant can change the content of trivalent manganese in the sintered material and promote the single crystallization of the sintered material. By changing the content of trivalent manganese in the sintered material, the disorder degree can be adjusted on the basis of a matrix mainly composed of an ordered spinel phase, and the effect of promoting single crystallization can make the single crystal particles of the obtained material at the micron level, with a small specific surface area and excellent capacity. Furthermore, the present disclosure can induce the tetravalent manganese on the surface of the sintered material as the matrix to be converted into trivalent manganese through surface thermal reduction, increase the content of trivalent manganese, and fully convert the surface layer of the material into disordered spinel, constructing a thin layer of disordered phase on the surface. Through the method of dopants and surface thermal reduction, the present disclosure can not only increase the disorder and morphology of the system, but also improve the capacity, cycle and rate performance of the disordered spinel phase lithium nickel manganese oxide material.

Claims

1. A disordered spinel phase lithium nickel manganese oxide material, characterized in that: It includes: A lithium nickel manganese oxide matrix mainly composed of an ordered spinel phase and a surface layer mainly composed of a disordered spinel phase formed on the surface of the matrix, wherein the matrix contains doping elements for increasing disorder and / or promoting single crystallization.

2. The disordered spinel phase lithium nickel manganese oxide material according to claim 1, characterized in that: The content of trivalent manganese in the matrix is ​​5%-20%, and the content of trivalent manganese in the surface layer is 30-50%.

3. A disordered spinel phase lithium nickel manganese oxide material according to any one of claims 1-2, characterized in that: The doping element includes at least one of Mg, Al, P, Fe, Ti, W, Mo, Nb, Y and Zr.

4. The disordered spinel phase lithium nickel manganese oxide material according to claim 3, characterized in that: The doping element for improving disorder includes at least one of Al, P and Mo; the doping element for promoting single crystallization includes at least one of Nb and Mo.

5. A disordered spinel phase lithium nickel manganese oxide material according to any one of claims 1 to 4, characterized in that: The mass of the surface layer accounts for 5-30% of the disordered transformed spinel phase lithium nickel manganese oxide material.

6. A disordered spinel phase lithium nickel manganese oxide material according to any one of claims 1 to 5, characterized in that: The particle size of the disordered spinel phase lithium nickel manganese oxide material is 4-6 μm.

7. A disordered spinel phase lithium nickel manganese oxide material according to any one of claims 1 to 6, characterized in that: The thickness of the surface layer is 100-500nm.

8. A method for preparing a disordered spinel phase lithium nickel manganese oxide material, characterized in that: It includes: calcining a mixture containing nickel, manganese, lithium and a dopant, cooling the mixture after calcination, and annealing the mixture at the same temperature to obtain a sintered material; The sintering material is mixed with a reducing agent to perform surface thermal reduction to increase the content of trivalent manganese on the surface of the sintering material.

9. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to claim 8, characterized in that: The doping element in the dopant includes at least one of Mg, Al, P, Fe, Ti, W, Mo, Nb, Y and Zr.

10. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 9, characterized in that: The content of any one of the dopants is 1000-5000 ppm.

11. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 10, characterized in that: The mass of the reducing agent is 0.5-5% of the mass of the sintering material.

12. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 11, characterized in that: The reducing agent includes a carbon source.

13. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to claim 12, characterized in that: The carbon source comprises at least one of glucose, sucrose, PEG, phenolic resin and resorcinol-formaldehyde resin.

14. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 13, characterized in that: The calcination and the heat preservation annealing are both performed in a first atmosphere, and the oxygen partial pressure of the first atmosphere is greater than or equal to 70%.

15. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 14, characterized in that: The calcination temperature is 800-1000° C., and the calcination time is 10-20 hours.

16. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 15, characterized in that: The temperature of the heat preservation annealing is 600-700° C., and the annealing time is 5-10 hours.

17. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 16, characterized in that: The surface thermal reduction is performed in a second atmosphere, and the oxygen partial pressure of the second atmosphere is less than or equal to 30%.

18. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to claim 17, characterized in that: The second atmosphere is at least one of hydrogen and carbon monoxide.

19. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 18, characterized in that: The temperature of the surface thermal reduction is 300-600° C., and the calcination time is 1-5 hours.

20. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 19, characterized in that: Before mixing the sintering material and the reducing agent, the method further includes crushing the sintering material.

21. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to claim 20, characterized in that: The crushing includes firstly using crushing rollers for coarse crushing and then using air flow crushing for graded crushing.

22. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to claim 21, characterized in that: The crushing rollers are two opposite to each other with a gap of 0.1-0.3 mm. The particles coarsely crushed by the crushing rollers have a Dv10 of 4-6 μm, a Dv50 of 7-12 μm, and a Dv90 of 20-25 μm.

23. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 21-22, characterized in that: The particles produced by the gas flow crushing for graded crushing have a Dv10 of 1-2 μm, a Dv50 of 4-8 μm, and a Dv90 of 8-20 μm.

24. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 8 to 23, characterized in that: The nickel and manganese in the mixture are provided in the form of a nickel-manganese compound precursor. The preparation method of the nickel-manganese compound precursor comprises: preparing a nickel source and a manganese source into a transition metal solution; then adding an excess of a precipitant to the transition metal solution for reaction, cooling, filtering, washing, and drying to obtain the nickel-manganese compound precursor.

25. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to claim 24, characterized in that: The molar ratio of nickel to manganese in the nickel source and the manganese source is 1:

3.

26. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 24-25, characterized in that: The manganese source includes at least one of manganese hydroxide, manganese sulfate, manganese carbonate and manganese acetate.

27. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 24 to 26, characterized in that: The nickel source includes at least one of nickel hydroxide, nickel sulfate, nickel carbonate and nickel acetate.

28. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to any one of claims 24 to 27, characterized in that: The lithium is provided by a lithium source, and the lithium source includes one or more of lithium hydroxide, lithium carbonate, lithium sulfate, and lithium acetate, and the purity is greater than 98%.

29. The method for preparing the disordered spinel phase lithium nickel manganese oxide material according to claim 28, characterized in that: The molar ratio of lithium to nickel manganese in the lithium source and the nickel manganese compound precursor is 0.48-0.55:

1.

30. Use of the disordered spinel phase lithium nickel manganese oxide material as described in any one of claims 1 to 7 or the disordered spinel phase lithium nickel manganese oxide material prepared by the preparation method of the disordered spinel phase lithium nickel manganese oxide material as described in any one of claims 8 to 29 in preparing a positive electrode of a lithium battery.

31. A lithium ion battery comprising a positive electrode sheet, a negative electrode sheet, a separator arranged between the positive electrode sheet and the negative electrode sheet, and an electrolyte, characterized in that: The positive electrode plate contains the disordered spinel phase lithium nickel manganese oxide material as described in any one of claims 1 to 7 or the disordered spinel phase lithium nickel manganese oxide material prepared by the preparation method of the disordered spinel phase lithium nickel manganese oxide material as described in any one of claims 8 to 29.

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