Positive electrode material precursor containing molybdenum element, preparation method of positive electrode material precursor, positive electrode material, lithium ion battery and electric equipment

Abstract

The invention provides a molybdenum-containing positive electrode material precursor and a preparation method thereof, a positive electrode material, a lithium ion battery and electric equipment, the molybdenum-containing positive electrode material precursor comprises secondary particles with a core-shell structure, the core-shell structure comprises an inner core and an outer shell located on the outer side of the inner core, the molybdenum element is mainly distributed in the inner core of the secondary particle, and the content of the molybdenum element in the inner core is 18000-22000 ppm; the difference between the porosity of the inner core and the porosity of the shell is larger than or equal to 18%. The positive electrode material precursor containing the molybdenum element in the embodiment of the invention comprises the secondary particles with the core-shell structure, the inner core is loose and is doped with molybdenum, the chemical and physical stability of the inner core is improved, and meanwhile, the material can be ensured to have relatively high capacity, cycle and rate performance in cooperation with the non-doped compact shell.

Description

Technical Field

[0001] This application belongs to the technical field of cathode materials for batteries, and particularly relates to a cathode material precursor containing molybdenum element, a preparation method thereof, a cathode material, a lithium-ion battery, and an electricity-related device. Background Art

[0002] Lithium-ion batteries have been widely used in the fields of portable electronic devices, electric vehicles, and large-scale energy storage due to their outstanding advantages such as high energy density, long cycle life, and low self-discharge rate. With the rapid development of various application fields, the performance requirements for lithium-ion batteries are also increasing day by day. Especially in high-power application scenarios, such as rapid acceleration, climbing, and instantaneous high-power discharge of electric vehicles, there are strict requirements for the high-power performance of the battery.

[0003] Developing high-performance cathode material precursors with high specific capacity and high cycle performance has become a research hotspot and key direction in the current lithium-ion battery field. Summary of the Invention

[0004] To solve the above problems, this application provides a cathode material precursor containing molybdenum element, a preparation method thereof, a cathode material, a lithium-ion battery, and an electricity-related device, which can enable the battery to have a higher capacity, better cycle and rate performance.

[0005] In a first aspect, an embodiment of this application provides a cathode material precursor containing molybdenum element. The cathode material precursor containing molybdenum element includes secondary particles having a core and a shell structure. The molybdenum element is mainly distributed in the core of the secondary particles, and the content of the molybdenum element in the core is 18000 - 22000 ppm; the difference between the porosity of the core and the porosity of the shell is ≥ 18%.

[0006] According to the embodiment of the first aspect of this application, the content of the molybdenum element in the precursor is 300 - 2000 ppm.

[0007] According to the embodiment of the first aspect of this application, the chemical formula of the core is: Ni z2 , x2 , v1 , y1 , , , , p2 , y2 , p1 , z1 , x1 ,

[0007] ,

[0006] ,

[0005] Co y1 Mn z1 Mo v1 M1 p1 (OH)2, where x1 + y1 + z1 + v1 + p1 = 1, 0.50 ≤ x1 < 1, 0 < y1 ≤ 0.3, 0 < z1 ≤ 0.3, 0 ≤ p1 ≤ 0.1, and M1 is selected from one or more of W, Zr, Si, Mg, Al, B, Sr, Ti, Nb, or Ta; optionally, 0.80 ≤ x1 < 1; and / or, the chemical formula of the shell is: Ni x2 Co y2 Mn z2 M2 p2(OH)2, where x2 + y2 + z2 + p2 = 1, 0.50 ≤ x2 < 1, 0 ≤ y2 ≤ 0.3, 0 < z2 ≤ 0.3, 0 ≤ p2 ≤ 0.1, and M2 is selected from one or more of W, Zr, Si, Mg, Al, B, Mo, Sr, Ti, Nb, or Ta; optionally, 0.80 ≤ x2 < 1.

[0008] According to an embodiment of the first aspect of the present application, the precursor of the cathode material satisfies at least one of the following conditions:

[0009] (1) The roundness of the core is ≥90%;

[0010] (2) The D50 of the precursor is 8.0 - 15.0 μm;

[0011] (3) The specific surface area of the precursor is 8 - 15 m 2 / g;

[0012] (4) The tap density of the precursor is ≥1.8 g / cm 3 ;

[0013] (5) The thickness variance R of the shell 2 ≤0.1, preferably, R [[ID=~]] 2 ≤0.05;

[0014] (6) The porosity of the core is 20 - 30%;

[0015] (7) The porosity of the shell is 0.5 - 3%;

[0016] (8) The porosity of the precursor is 1 - 5%;

[0017] (9) The ratio of the cross-sectional area of the core to the cross-sectional area of the secondary particle is 5 - 15%;

[0018] (10) The shell includes a plurality of primary particles, and the primary particles are radially arranged in a radial direction.

[0019] In a second aspect, an embodiment of the present application provides a method for preparing a precursor of a cathode material containing molybdenum element, including the following steps: Under an inert gas atmosphere, mixing a precipitant solution and a complexing agent solution to obtain a first bottom liquid; First coprecipitation reaction: Under an inert gas atmosphere, introducing a metal salt solution 1, a molybdenum-containing solution, a precipitant solution, and a complexing agent solution into the first bottom liquid, and switching to an oxygen-containing atmosphere after reacting for a preset time to obtain seeds; Under an inert gas atmosphere, mixing the seeds and a complexing agent solution to obtain a second bottom liquid; Second coprecipitation reaction: Under an inert gas atmosphere, introducing a metal salt solution 2, a precipitant solution, and a complexing agent solution into the second bottom liquid, and reacting to obtain a precursor of a cathode material containing molybdenum element.

[0020] According to an embodiment of the second aspect of the present application, the preparation method satisfies at least one of the following conditions:

[0021] (a) the pH of the first base solution is 11.40-11.65;

[0022] (b) the concentration of the complexing agent in the first base solution is 3.8-5.2 g / L;

[0023] (c) the pH of the first coprecipitation reaction is 10.70 to 11.60;

[0024] (d) the concentration of the complexing agent during the first coprecipitation reaction is 3.0 to 4.5 g / L;

[0025] (e) the temperature of the first coprecipitation reaction is 55-65° C.;

[0026] (f) the pH of the second base solution is 10.30-10.55;

[0027] (g) the concentration of the complexing agent in the second base solution is 3.8-5.2 g / L;

[0028] (h) the pH of the second coprecipitation reaction is 10.30 to 10.65;

[0029] (i) the concentration of the complexing agent during the second coprecipitation reaction is 3.0 to 4.5 g / L;

[0030] (j) the temperature of the second coprecipitation reaction is 50-60° C.;

[0031] (k) The preset time is 4-8 hours;

[0032] (1) the second coprecipitation reaction was stopped after the D50 of the precipitate was 8-15 μm;

[0033] (m) The preparation method further comprises post-processing the precipitate; optionally, the post-processing comprises solid-liquid separation, washing, and drying.

[0034] According to an embodiment of the second aspect of the present application, the preparation method satisfies at least one of the following conditions:

[0035] (A) The metal salt solution 1 includes nickel ions and manganese ions, wherein the molar percentage of nickel ions is 50%-100% based on the total amount of metal ions in the metal salt solution 1; preferably, the molar percentage of nickel ions is 80%-100%; optionally, the metal salt solution 1 further includes cobalt ions; optionally, the metal salt solution further includes M1 ions, wherein M1 is selected from one or more of W, Zr, Si, Mg, Al, B, Sr, Ti, Nb or Ta;

[0036] (B) The concentration of metal ions in the metal salt solution 1 is 120 g / L to 240 g / L;

[0037] (C) the precipitant solution is a sodium hydroxide solution;

[0038] (D) the complexing agent solution is aqueous ammonia;

[0039] (E) the molybdenum-containing solution is a molybdenum trioxide solution; optionally, the concentration of the molybdenum-containing solution is 6.5-8.5 g / L;

[0040] (F) During the first coprecipitation reaction, the flow ratio of the metal salt solution, the molybdenum-containing solution, the precipitant solution, and the complexing agent solution is 1.5-2.5:0.5-1.5:0.3-0.9:0.05-0.13;

[0041] (G) The metal salt solution 2 includes nickel ions and manganese ions, wherein the amount of nickel ions is 50%-100% based on the total amount of metal ions in the metal salt solution 2; optionally, the amount of nickel ions is 80%-100%; optionally, the metal salt solution 2 further includes cobalt ions; optionally, the metal salt solution 2 further includes M2 ions, M2 being selected from one or more of W, Zr, Si, Mg, Al, B, Sr, Ti, Nb or Ta;

[0042] (H) The concentration of metal ions in the metal salt solution 2 is 120 g / L to 240 g / L;

[0043] (I) During the second coprecipitation reaction, the flow ratio of the metal salt solution 2, the precipitant solution, and the complexing agent solution is 0.5-1.5:0.26-0.46:0.02-0.04.

[0044] In a third aspect, the present application provides a positive electrode material, which is obtained by mixing and sintering the positive electrode material precursor containing molybdenum element in the first aspect of the present application with a lithium source, or by mixing and sintering the positive electrode material precursor containing molybdenum element prepared by the preparation method of the second invention of the present application with a lithium source.

[0045] In a fourth aspect, the present application provides a lithium-ion battery comprising the positive electrode material in the third aspect of the present application.

[0046] In a fifth aspect, the present application provides an electrical device, including the lithium-ion battery in the fourth aspect of the present application.

[0047] The molybdenum-containing cathode material precursor in the embodiments of this application includes secondary particles having a core and shell structure. The core is loose, and molybdenum-doped to enhance the chemical and physical stability of the core. Combined with the dense shell, this ensures the material has high capacity, cycle, and rate performance. Using a small amount of molybdenum in the embodiments of this application achieves the technical effect of improving product performance while saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a SEM image of the cathode material precursor provided in Example 1 of this application;

[0049] Figure 2 This is an EDS image of the cathode material precursor provided in Example 1 of this application;

[0050] Figure 3 This is an SEM image of the cathode material precursor provided in Example 2 of this application;

[0051] Figure 4 This is a SEM image of the cathode material precursor provided in Example 5 of the present application;

[0052] Figure 5 This is an SEM image of the cathode material precursor provided in Comparative Example 1 of this application;

[0053] Figure 6 This is an SEM image of the cathode material precursor provided in Comparative Example 2 of this application;

[0054] Figure 7 This is an SEM image of the positive electrode material precursor provided in Comparative Example 3 of this application. DETAILED DESCRIPTION

[0055] In order to make the application purpose, technical solution and beneficial technical effects of this application clearer, the application is further described in detail below with reference to the embodiments. It should be understood that the embodiments described in this specification are only for explaining this application and are not intended to limit this application.

[0056] For simplicity, this application only explicitly discloses certain numerical ranges. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, although not explicitly stated, each point or individual value between the endpoints of a range is included in the range. Thus, each point or individual value may serve as its own lower limit or upper limit and be combined with any other point or individual value, or with other lower limits or upper limits, to form an unspecified range.

[0057] As used herein:

[0058] In the description of this application, it should be noted that, unless otherwise specified, “above” and “below” are inclusive of the number, and “a variety” in “one or more” means two or more.

[0059] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations 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.

[0060] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding 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.

[0061] 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 alone. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "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 herein, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0062] In these examples, parts and percentages are by mass unless otherwise indicated.

[0063] "Parts by mass" refers to the basic unit of measurement used to express the mass ratio of multiple components. One part can represent any unit of 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, this means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, we could say that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number representing a multiplication factor). It's important to note that, unlike parts by mass, the sum of the mass of all components is not limited to 100 parts.

[0064] "And / or" is used to indicate that one or both of the described situations may occur. For example, A and / or B includes (A and B) and (A or B). It should be clarified that the descriptions such as "thin" in the present invention specifically refer to the morphological characteristics of the corresponding structure in the positive electrode material precursor and should not be understood as specific quantification.

[0065] In the present invention, the particle size D50 and the average particle size have the same meaning, and refer to the particle size corresponding to when the cumulative particle size distribution percentage of the positive electrode material precursor reaches 50%.

[0066] The cross section of a sphere refers to a planar figure obtained by cutting a sphere or a spheroid with a plane. In the present invention, unless otherwise specified, the secondary particle cross section and the secondary particle profile have the same meaning, which refers to a planar figure formed by a plane passing through the center of the sphere or the center of the particle.

[0067] In the present invention, the porosity of the secondary particles refers to the internal porosity of the secondary particles, which is measured by porosity statistical software.

[0068] In the present invention, unless otherwise specified, the core and shell of the secondary particles are distinguished in that the arrangement of the primary particles in the core layer and the shell layer is significantly different. Specifically, the primary particles in the core layer are distributed in a network or flocculent manner, while the primary particles in the shell layer are distributed radially.

[0069] The porosity test method is: use image analysis software (Image-Pro Plus) to directly calculate the pore area and cross-sectional area of ​​the CP profile, and calculate the porosity of different areas by "internal porosity = area of ​​pore area in the internal cross-sectional area of ​​secondary particles / area of ​​the cross-sectional area of ​​secondary particles × 100%". The porosity in this article is characterized by this method.

[0070] In the present invention, the kernel roundness calculation method is as follows: using the cross-section (CP) image, the long axis and the short axis of the kernel are determined, where the long axis is the longest distance in the kernel and the short axis is the longest distance perpendicular to the long axis. Kernel roundness = short axis / long axis.

[0071] In the present invention, the core ratio is calculated by using a cross-section (CP) image to distinguish the boundary between the core and the shell according to the different morphologies, and fitting the area of ​​the core and the area of ​​the secondary particle cross section respectively. The core ratio = core cross section area / overall particle cross section area.

[0072] In the present invention, the shell thickness variance refers to the degree of dispersion of the shell thickness of each secondary particle relative to the average thickness in the same batch of secondary particles.

[0073] In the present invention, the method for calculating the variance of the precursor shell thickness is as follows: a cross-section (CP) picture of a secondary particle is selected, the intersection of the major axis and the minor axis is determined as the center O, n points (for example, n can be 5, 10, 15 or 20) are randomly selected from the periphery of the cross section of the secondary particle, and the center O is connected with points Q1, Q2, Q3, Q4...Qn on the periphery, and the intersection points of OQ1, OQ2, OQ3, OQ4...OQn with the periphery of the core are P1, P2, P3, P4...Pn, respectively. The lengths of P1Q1, P2Q2, P3Q3, P4Q4...PnQn are measured to be X1, X2, X3, X4...Xn, the average shell thickness X0 of the secondary particle is the average value of X1, X2, X3, X4...Xn, and the shell thickness variance of the secondary particle is R 2 ={(X1-X0) 2 +(X2-X0) 2 +(X3-X0) 2 +......+(X n -X0) 2} / n.

[0074] In today's context of increasingly urgent demand for high-power, high-safety and long-cycle-life battery applications, positive electrode materials have become an important development direction for lithium-ion battery positive electrode materials due to their advantages such as high energy density and good cycle stability.

[0075] The present application provides a positive electrode material precursor containing molybdenum element and its preparation method, positive electrode material, lithium ion battery and electrical equipment, which can enable the battery to have higher capacity, better cycle and rate performance.

[0076] In the first aspect, an embodiment of the present application provides a positive electrode material precursor containing molybdenum element, and the positive electrode material precursor containing molybdenum element includes secondary particles having a core and a shell structure, and the molybdenum element is mainly distributed in the core of the secondary particles, and the content of the molybdenum element in the core is 18000~22000ppm; the difference between the porosity of the core and the porosity of the shell is ≥18%.

[0077] The positive electrode material precursor provided in the embodiment of the present application comprises secondary particles having a core-shell structure, that is, the secondary particles have a core and shell structure. In the embodiment of the present application, the core and the shell have a large porosity difference. The loose core provides more electrolyte contact sites, providing a smoother channel for the transmission of lithium ions, accelerating the insertion and extraction speed of lithium ions in the positive electrode material, thereby improving the charge and discharge efficiency of the battery. The loose core can also alleviate the stress generated by volume changes during the charge and discharge process and provide basic support. The shell is densely wrapped, which can alleviate the volume changes during charge and discharge, inhibit structural collapse, and effectively reduce the pulverization and rupture of the material during long-term cycling, thereby improving the cycle life of the battery.

[0078] The embodiment of the present application improves the chemical and physical stability of the core by doping molybdenum in the core, and at the same time, combined with the dense structure of the shell, the material has higher capacity, cycle and rate performance.

[0079] In the embodiment of the present application, molybdenum is doped only in the core, and the usage of molybdenum is greatly reduced, which can save costs. At the same time, since the doping amount of molybdenum is low relative to the overall mass of the precursor, the product capacity can be retained to a large extent.

[0080] The molybdenum element is mainly distributed in the inner core of the secondary particles, where "mainly" means that greater than or equal to 70% of the molybdenum element is distributed in the inner core, calculated based on the total mass of the molybdenum element in the secondary particles, for example, 70%, 75%, 80%, 85%, 90%, 95% or 100% of the molybdenum element is distributed in the inner core.

[0081] Specifically, based on the total mass of the core, the content of molybdenum in the core is 18,000 to 22,000 ppm; more specifically, the content of molybdenum in the core is calculated by the total amount of metal salt and the total amount of molybdenum source used in the crystal core preparation process.

[0082] Illustratively, the content of molybdenum in the secondary core is approximately any value among 18000 ppm, 18500 ppm, 19000 ppm, 19500 ppm, 20000 ppm, 20500 ppm, 21000 ppm, 21500 ppm and 22000 ppm, or a range between any two of them.

[0083] In some embodiments, the content of molybdenum in the precursor is 300 to 2000 ppm based on the total mass of the precursor; more specifically, the content of molybdenum in the precursor is calculated by the total amount of metal salt and the total amount of molybdenum source used in the precursor preparation process.

[0084] Exemplarily, the content of molybdenum element in the precursor is any value among 300 ppm, 400 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm, 900 ppm, 1000 ppm, 1100 ppm, 1200 ppm, 1300 ppm, 1400 ppm, 1500 ppm, 1600 ppm, 1700 ppm, 1800 ppm, 1900 ppm and 2000 ppm or a range value between any two of them.

[0085] In some embodiments, the chemical formula of the core is: Ni x1 Co y1 Mn z1 Mo v1 M1 p1 (OH)2, where x1 + y1 + z1 + v1 + p1 = 1, 0.50 ≤ x1 < 1, 0 ≤ y1 ≤ 0.3, 0 < z1 ≤ 0.3, 0 ≤ p1 ≤ 0.1, and M1 is selected from one or more of W, Zr, Si, Mg, Al, B, Sr, Ti, Nb or Ta; optionally, 0.80 ≤ x1 < 1.

[0086] In some embodiments, the chemical formula of the shell is: Ni x2 Co y2 Mn z2 M2 p2 (OH)2, where x2 + y2 + z2 + p2 = 1, 0.50 ≤ x2 < 1, 0 ≤ y2 ≤ 0.3, 0 < z2 ≤ 0.3, 0 ≤ p2 ≤ 0.1, and M2 is selected from one or more of W, Zr, Si, Mg, Al, B, Mo, Sr, Ti, Nb or Ta; optionally, 0.80 ≤ x2 < 1.

[0087] In the embodiments of the present application, nickel (Ni), cobalt (Co), and manganese (Mn) are the core metal elements in the precursor of the cathode material, and the electrochemical performance, structural stability and safety of the material are determined by their synergistic effect.

[0088] Exemplarily, the value of x1 can be any value among 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86,​​Illustratively, the value of y1 can be any value among 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29 and 0.30, or a range between any two of them.

[0090] Illustratively, the value of z1 can be any value among 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29 and 0.30, or a range between any two of them.

[0091] Illustratively, the value of p1 can be any value among 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, or a range between any two values.

[0092] Illustratively, the value of x2 can be any value among 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98 and 0.99, or a range value between any two of them. Optionally, 0.80≤x<1.

[0093] Illustratively, the value of y2 can be any value among 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29 and 0.30, or a range between any two of them.

[0094] Illustratively, the value of z2 can be any value among 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29 and 0.30, or a range between any two of them.

[0095] Illustratively, the value of p2 can be any value among 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 and 0.1, or a range of values ​​between any two of them.

[0096] In some embodiments, the circularity of the inner core is ≥ 90%.

[0097] In the embodiment of the present application, the inner core of the secondary particles has a high degree of roundness, which can, on the one hand, enhance the support of the inner core, thereby enhancing the strength of the particles; on the other hand, it is beneficial to the growth inheritance of large particles, enhances the uniformity of the outer shell thickness, and can make the transmission paths of lithium ions in all directions close, thereby improving the rate performance.

[0098] Illustratively, the circularity of the kernel is any value among 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% and 100%, or any range therebetween.

[0099] In some embodiments, the D50 of the cathode material precursor containing molybdenum is 8.0-15.0 μm.

[0100] Illustratively, the D50 of the cathode material precursor containing molybdenum is any value among 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm and 15 μm, or a range between any two of them.

[0101] In some embodiments, the specific surface area of ​​the cathode material precursor containing molybdenum is 8-15 m 2 / g.

[0102] For example, the specific surface area of ​​the cathode material precursor containing molybdenum is 8 m 2 / g、9m 2 / g、10m 2 / g、11m 2 / g、12m 2 / g、13m 2 / g、14m 2 / g and 15m 2Any value in / g or any range between them.

[0103] In some embodiments, the tap density of the cathode material precursor containing molybdenum is ≥1.8 g / cm 3 .

[0104] For example, the tap density of the cathode material precursor containing molybdenum is 1.8 g / cm 3 , 1.9g / cm 3 , 2.0g / cm 3 , 2.1g / cm 3 , 2.2g / cm 3 and 2.3 g / cm 3 Any value in or greater than 1.8 g / cm 3 Any value or any range of values ​​between them.

[0105] In some embodiments, the thickness variance R of the shell of the secondary particles is 2 ≤0.1.

[0106] Illustratively, the thickness variance of the shell is 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 and 0.1 or any value less than 0.1 or any range of values ​​therebetween.

[0107] Optionally, R 2 ≤0.05, and a small variance indicates that the shell thickness of the secondary particles is uniform, corresponding to a stable structure and consistent performance.

[0108] In some embodiments, the porosity of the core of the secondary particle is 20-30%.

[0109] In some embodiments, the porosity of the shell of the secondary particles is 0.5-3%.

[0110] In some embodiments, the porosity of the positive electrode material precursor containing molybdenum is 1-5%.

[0111] Illustratively, the porosity of the inner core can be any value among 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% and 30%, or any range therebetween.

[0112] Illustratively, the porosity of the shell can be any value among 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9% and 3%, or any range therebetween.

[0113] Illustratively, the porosity of the positive electrode material precursor containing molybdenum element can be any value among 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.5%, 2.6%, 2.8%, 3%, 3.2%, 3.4%, 3.5%, 3.6%, 3.8%, 4%, 4.2%, 4.4%, 4.5%, 4.6%, 4.8% and 5%, or any range between two of them.

[0114] In some embodiments, the ratio of the cross-sectional area of ​​the inner core to the cross-sectional area of ​​the secondary particles is 5-15%.

[0115] In the embodiment of the present application, the proportion of the core is relatively small, so that the amount of molybdenum element used can be controlled, thereby reducing the impact of doping on the product capacity performance.

[0116] Illustratively, the ratio of the cross-sectional area of ​​the inner core to the cross-sectional area of ​​the secondary particles can be any value among 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% and 15%, or a range of values ​​between any two of them.

[0117] In some embodiments, the shell includes a plurality of primary particles, and the primary particles are arranged radially.

[0118] In the embodiments of this application, the radial arrangement of primary particles provides a clear guide for lithium ion transport. When lithium ions diffuse from the electrolyte to the surface of the secondary particles, the pores and channels formed by the radially arranged primary particles in the shell effectively reduce the resistance to lithium ion transport, allowing the battery to maintain good rate and cycle performance.

[0119] In a second aspect, an embodiment of the present application provides a method for preparing a positive electrode material precursor containing molybdenum, comprising the following steps: mixing a precipitant solution and a complexing agent solution under an inert gas atmosphere to obtain a first base liquid; a first coprecipitation reaction: introducing a metal salt solution 1, a molybdenum-containing solution, a precipitant solution and a complexing agent solution into the base liquid under an inert gas atmosphere, and switching to an oxygen-containing atmosphere after a preset reaction time to obtain a seed crystal; mixing the seed crystal and the complexing agent solution under an inert gas atmosphere to obtain a second base liquid; a second coprecipitation reaction: introducing a metal salt solution 2, a precipitant solution and a complexing agent solution into the second base liquid under an inert gas atmosphere, and reacting to obtain a positive electrode material precursor containing molybdenum.

[0120] The preparation method of the present invention employs a step-by-step coprecipitation strategy, introducing a molybdenum-containing solution during the first coprecipitation reaction. This allows the molybdenum element to be primarily concentrated in the seed crystal core, achieving molybdenum enrichment there. This controlled element distribution lays the foundation for the subsequent formation of a precursor with a core-shell structure and a molybdenum-rich core, ensuring that the precursor fully utilizes the molybdenum element's enhanced structural stability to improve battery performance.

[0121] The process of forming a seed crystal through a first coprecipitation reaction and then growing a shell on top of the seed crystal through a subsequent second coprecipitation reaction effectively controls the porosity of the core and shell. Differences in reaction conditions at different stages result in distinct microstructures of the core and shell during formation, achieving the design requirement of a ≥18% difference in core-shell porosity.

[0122] In some embodiments, the pH of the first base solution is 11.40-11.65.

[0123] Illustratively, the pH of the first base solution is any value among 11.40, 11.45, 11.50, 11.55, 11.60 or 11.65, or a range of values ​​between any two of them.

[0124] In some embodiments, the concentration of the complexing agent in the first base solution is 3.8-5.2 g / L.

[0125] Illustratively, the concentration of the complexing agent in the first base liquid is any value among 3.8 g / L, 3.9 g / L, 4.0 g / L, 4.1 g / L, 4.2 g / L, 4.3 g / L, 4.4 g / L, 4.5 g / L, 4.6 g / L, 4.7 g / L, 4.8 g / L, 4.9 g / L, 5.0 g / L, 5.1 g / L and 5.2 g / L, or a range value between any two of them.

[0126] In some embodiments, the pH of the first coprecipitation reaction is 10.70-11.60.

[0127] Illustratively, the pH of the first coprecipitation reaction is any value among 10.70, 10.80, 10.90, 11.00, 11.10, 11.20, 11.30, 11.40, 11.50 or 11.60, or a range of values ​​therebetween.

[0128] For example, the change in pH during the first coprecipitation reaction is to control the pH to gradually decrease from 11.55 to 11.60 to 10.90 to 10.70 within a certain period of time.

[0129] In some embodiments, the concentration of the complexing agent during the first coprecipitation reaction is 3.0-4.5 g / L.

[0130] Illustratively, the concentration of the complexing agent during the first coprecipitation reaction is any value among 3.0 g / L, 3.2 g / L, 3.4 g / L, 3.6 g / L, 3.8 g / L, 4.0 g / L, 4.1 g / L, 4.2 g / L, 4.3 g / L, 4.4 g / L and 4.5 g / L, or a range value between any two of them.

[0131] For example, during the first coprecipitation reaction, the concentration of the complexing agent decreases from 4.5 g / L to 4.0 g / L within a certain period of time. Specifically, the free ammonia concentration is controlled at 4.5 g / L from 0 to 8 hours, and the free ammonia concentration is controlled at 4.0 g / L from 8 hours to shutdown.

[0132] In some embodiments, the temperature of the first coprecipitation reaction is 55-65°C.

[0133] Illustratively, the temperature of the first coprecipitation reaction is any value of 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C and 65°C, or a range between any two of them.

[0134] In some embodiments, the pH of the second base solution is 10.30-10.55.

[0135] Illustratively, the pH of the second base solution is any value among 10.30, 10.35, 10.40, 10.45, 10.50 or 10.55, or a range of values ​​between any two of them.

[0136] In some embodiments, the concentration of the complexing agent in the second base solution is 3.8-5.2 g / L.

[0137] Illustratively, the concentration of the complexing agent in the second base liquid is any value among 3.8 g / L, 3.9 g / L, 4.0 g / L, 4.1 g / L, 4.2 g / L, 4.3 g / L, 4.4 g / L, 4.5 g / L, 4.6 g / L, 4.7 g / L, 4.8 g / L, 4.9 g / L, 5.0 g / L, 5.1 g / L and 5.2 g / L, or a range value between any two of them.

[0138] In some embodiments, the pH of the second co-precipitation reaction is 10.30-10.65.

[0139] Illustratively, the pH of the second coprecipitation reaction is any value among 10.30, 10.35, 10.40, 10.45, 10.50, 10.55, 10.60 or 10.65, or a range of values ​​therebetween.

[0140] Illustratively, the pH change process of the second coprecipitation reaction is to control the pH value to rise from 10.30 to 10.40 to 10.60 to 10.65 within a certain period of time and then drop to 10.50 to 10.30.

[0141] In some embodiments, the concentration of the complexing agent during the second coprecipitation reaction is 3.0-4.5 g / L.

[0142] Illustratively, the concentration of the complexing agent during the second coprecipitation reaction is any value among 3.0 g / L, 3.2 g / L, 3.4 g / L, 3.6 g / L, 3.8 g / L, 3.8 g / L, 3.9 g / L, 4.0 g / L, 4.1 g / L, 4.2 g / L, 4.3 g / L, 4.4 g / L and 4.5 g / L, or a range value between any two of them.

[0143] For example, during the second coprecipitation reaction, the complexing agent concentration decreases from 4.5 g / L to 3.8 g / L within a certain period of time. Specifically, the free ammonia concentration is controlled at 4.5 g / L from 0 to 5 h, and the free ammonia concentration is controlled at 3.8 g / L from 5 h to the shutdown.

[0144] In some embodiments, the temperature of the second co-precipitation reaction is 50-60°C.

[0145] Illustratively, the temperature of the second coprecipitation reaction is any value of 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C and 60°C, or a range between any two thereof.

[0146] In some embodiments, the preset time is 4-8 hours.

[0147] Exemplarily, the preset time is any value among 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h and 8h, or a range value between any two of them.

[0148] In some embodiments, the second co-precipitation reaction is stopped after the D50 of the precipitate reaches 8-15 μm.

[0149] In some embodiments, the preparation method further comprises post-processing the precipitate.

[0150] The precipitate is post-treated to remove impurity ions attached to the surface to obtain a purified product.

[0151] In some embodiments, post-processing includes solid-liquid separation, washing and drying. Exemplarily, the solid-liquid separation is performed by filtration.

[0152] Illustratively, the washing is performed alternately with deionized water and ethanol for 3-5 times to ensure that the precipitate is fully washed, and then the precipitate is dried at a temperature of 80-120° C. for 12-24 hours to remove moisture and obtain a positive electrode material precursor containing molybdenum.

[0153] In some embodiments, the metal salt solution 1 includes nickel ions and manganese ions, wherein the molar percentage of the nickel ions is 50%-100% based on the total amount of metal ions in the metal salt solution 1 .

[0154] In some embodiments, the metal salt solution 1 includes nickel ions and manganese ions, wherein the molar percentage of nickel ions is 80%-100% based on the total amount of metal ions in the metal salt solution 1 .

[0155] In some embodiments, the metal salt solution 1 further includes cobalt ions.

[0156] In some embodiments, the metal salt solution 1 further includes M1 ions, wherein M1 is selected from one or more of W, Zr, Si, Mg, Al, B, Sr, Ti, Nb or Ta.

[0157] In some embodiments, the concentration of metal ions in the metal salt solution 1 is 120 g / L to 240 g / L.

[0158] Illustratively, the concentration of metal ions in the metal salt solution 1 is any value of 120 g / L, 130 g / L, 140 g / L, 150 g / L, 160 g / L, 170 g / L, 180 g / L, 190 g / L, 200 g / L, 210 g / L, 220 g / L, 230 g / L, 240 g / L, or a range value between any two of them.

[0159] In some embodiments, the precipitant solution is an alkaline solution, which can be a sodium hydroxide (NaOH) solution, a potassium hydroxide (KOH) solution or a lithium hydroxide (LiOH) solution, preferably a sodium hydroxide solution, and its concentration can be adjusted in the range of 30-35 wt% according to the chemical composition of the target product and the reaction requirements.

[0160] In some embodiments, the complexing agent solution is aqueous ammonia.

[0161] The introduction of the complexing agent solution can adjust the pH value of the reaction system and the complexing state of the metal ions, and promote the uniform precipitation of the metal ions.

[0162] In some embodiments, the molybdenum-containing solution is a molybdenum trioxide solution. Optionally, the concentration of molybdenum ions in the molybdenum-containing solution is 6.0-10.0 g / L.

[0163] Exemplarily, the concentration of the molybdenum-containing solution is any value of 6.5 g / L, 6.6 g / L, 6.7 g / L, 6.8 g / L, 6.9 g / L, 7.0 g / L, 7.1 g / L, 7.2 g / L, 7.3 g / L, 7.4 g / L, 7.5 g / L, 7.6 g / L, 7.7 g / L, 7.8 g / L, 7.9 g / L, 8.0 g / L, 8.1 g / L, 8.2 g / L, 8.3 g / L, 8.4 g / L and 8.5 g / L, or a range value between any two of them.

[0164] In some embodiments, during the first coprecipitation reaction, the flow ratio of the metal salt solution 1, the molybdenum-containing solution, the precipitant solution, and the complexing agent solution is 1.5-2.5: 0.5-1.5: 0.3-0.9: 0.05-0.13.

[0165] In some embodiments, the metal salt solution 2 includes nickel ions and manganese ions, wherein the molar percentage of the nickel ions is 50%-100% based on the total amount of metal ions in the metal salt solution 2.

[0166] In some embodiments, the metal salt solution 2 includes nickel ions and manganese ions, wherein the molar percentage of nickel ions is 80%-100% based on the total amount of metal ions in the metal salt solution 2 .

[0167] In some embodiments, the metal salt solution 2 further includes cobalt ions.

[0168] In some embodiments, the metal salt solution 2 further includes M2 ions, wherein M2 is selected from one or more of W, Zr, Si, Mg, Al, B, Mo, Sr, Ti, Nb or Ta.

[0169] In some embodiments, during the second coprecipitation reaction, the flow ratio of the metal salt solution 2, the precipitant solution, and the complexing agent solution is 0.5-1.5:0.26-0.46:0.02-0.04.

[0170] Illustratively, the cobalt ion source may include one or more of cobalt hydroxide, cobalt carbonate, cobalt nitrate, and cobalt acetate.

[0171] Illustratively, the manganese ion source includes manganese hydroxide (Mn(OH)2), manganese carbonate (MnCO3), manganese nitrate (Mn(NO3)2·4H2O), manganese sulfate (MnSO4·H2O), and the like.

[0172] Illustratively, the nickel ion source includes nickel hydroxide (Ni(OH)2), nickel carbonate (NiCO3), nickel nitrate (Ni(NO3)2·6H2O), nickel acetate (Ni(CH3COO)2·4H2O), and the like.

[0173] The metal salt solution 1 and the metal salt solution 2 may be the same or different.

[0174] In a third aspect, the present application provides a positive electrode material, which is obtained by mixing and sintering the positive electrode material precursor containing molybdenum element in the first aspect of the present application with a lithium source, or by mixing and sintering the positive electrode material precursor containing molybdenum element prepared by the preparation method of the second invention of the present application with a lithium source.

[0175] Select a suitable lithium source, such as lithium carbonate (Li2CO3) or lithium hydroxide (LiOH·H2O). Based on the chemical composition of the target cathode material and the stoichiometric ratio of lithium to metal elements, weigh the lithium source and dry precursor powder and mix them.

[0176] For example, the lithium source and the cathode material precursor are mixed by a high-speed mixer to ensure that the lithium source and the precursor are fully and evenly mixed, ensuring that the lithium element can evenly diffuse into the precursor lattice during the sintering process to form a uniform solid solution structure.

[0177] During mixing, the lithium source is in excess to compensate for the lithium volatilization loss during the high-temperature sintering process. Exemplarily, the molar ratio of the positive electrode material precursor to the lithium source is 1:1.03.

[0178] The uniformly mixed materials are sintered at high temperature, exemplarily in an air atmosphere, exemplarily in a box furnace, at a sintering temperature of 710° C., and for 12 hours.

[0179] In a fourth aspect, the present application provides a lithium-ion battery comprising the positive electrode material in the third aspect of the present application.

[0180] The lithium-ion battery provided in the embodiment of the present application includes the above-mentioned positive electrode material with a core-shell structure, which can enable the battery to have a higher capacity and better cycle and rate performance.

[0181] In some embodiments, a positive electrode material, conductive carbon black, and a binder may be mixed into a slurry and coated onto a current collector to form a positive electrode sheet. For example, the current collector is aluminum foil.

[0182] It is understandable that a lithium-ion battery also includes a negative electrode plate, a separator and an electrolyte.

[0183] The specific composition and structure of the negative electrode plate can be selected according to the type of lithium-ion battery, and the embodiments of the present application are not limited thereto.

[0184] In some embodiments, the separator may be a membrane. The present application has no particular limitation on the type of the membrane, and any known porous membrane with good chemical and mechanical stability may be used.

[0185] For example, the main material of the separator is selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation.

[0186] The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes electrolyte salt and solvent.

[0187] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0188] In certain embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0189] In a fifth aspect, the present application provides an electrical device, including the lithium-ion battery in the fourth aspect of the present application.

[0190] Example

[0191] The following examples more particularly describe the present disclosure, and these examples are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and used directly without further processing, and all instruments used in the examples are commercially available.

[0192] Example 1

[0193] A cathode material precursor containing molybdenum, wherein the molar ratio of Ni:Co:Mn in the precursor is 90.0:5.0:5.0, and the molybdenum content is 622ppm based on the overall mass of the precursor. The secondary particles of the precursor are spherical, with a particle size of 10.352μm and a specific surface area of ​​10.93m 2 / g, tap density is 1.93g / cm 2 . Figure 1 The cross-sectional structure of the precursor of the positive electrode material containing molybdenum element prepared in Example 1 is shown. It has a sparse inner and dense outer structure, a high inner core roundness, and a uniform outer shell thickness. Figure 2 The element distribution of the cathode material precursor provided in Example 1 is shown. Figure 2 It can be seen that molybdenum is mainly distributed in the core, and other elements are evenly distributed.

[0194] The positive electrode material precursor containing molybdenum element of this embodiment is prepared by the following steps:

[0195] Weighing and preparing the solution: Mix nickel sulfate solution, cobalt sulfate solution, manganese sulfate solution, and pure water until evenly distributed. Prepare a metal salt solution with a molar ratio of Ni:Co:Mn = 90.0:5.0:5.0, where the combined mass concentration of nickel, cobalt, and manganese ions is 120 g / L. Prepare a 7.5 g / L molybdenum trioxide solution.

[0196] Preparation of the first base liquid: pure water, sodium hydroxide solution, and ammonia solution were added to the reaction kettle, and nitrogen was introduced as a protective gas. The pH value was adjusted to 11.45 and the free ammonia concentration was 4.0 g / L to obtain the first base liquid.

[0197] First coprecipitation reaction: A metal salt solution, molybdenum trioxide solution, sodium hydroxide solution, and aqueous ammonia were introduced into the reactor at set flow rates to conduct a coprecipitation reaction. The flow ratio of the metal salt solution, molybdenum trioxide solution, sodium hydroxide solution, and aqueous ammonia was 2:1:0.6:0.08. The pH was controlled at 11.45 from 0 to 1 hour, 11.25 from 1 to 6 hours, 11.05 from 6 to 16 hours, 10.85 from 16 to 40 hours, and 10.80 from 40 hours to the end of the reaction. The reaction temperature was 62°C. The free ammonia concentration was controlled at 4.0 g / L from 0 to 8 hours and 3.0 g / L from 8 hours to the end of the reaction. Air was introduced after 4 hours of reaction until the reactor was stopped for weak oxidation. When the particle size reached the specified value, the feed was stopped. The material was directly spun dry to obtain seed crystals. The molybdenum content of the seed crystals was approximately 20,000 ppm.

[0198] Preparation of the second bottom liquid: pure water, ammonia solution, and seed crystals were added into the reactor, and nitrogen was introduced as a protective gas. The pH value was adjusted to 10.35 and the free ammonia concentration was 4.0 g / L to obtain the second bottom liquid.

[0199] Second coprecipitation reaction: A metal salt solution, sodium hydroxide solution, and aqueous ammonia were introduced into the reactor at a set flow rate to conduct a coprecipitation reaction. The flow rate ratio of the metal salt solution, sodium hydroxide solution, and aqueous ammonia was 1:0.36:0.03. The pH was controlled at 10.35 from 0 to 4 hours; 10.45 from 4 to 11 hours; 10.50 from 11 to 24 hours; and 10.40 after stopping the reactor after 24 hours. The reaction temperature was 57°C, and the free ammonia concentration was controlled at 4.0 g / L from 0 to 5 hours; and 3.3 g / L after stopping the reactor after 5 hours. Feeding was stopped when the reaction particle size reached the required value. The precursor was then washed, dried, sieved, demagnetized, and packaged.

[0200] Example 2

[0201] A cathode material precursor containing molybdenum, wherein the molar ratio of Ni:Co:Mn in the precursor is 90.0:5.0:5.0, and the molybdenum content is 725ppm based on the overall mass of the precursor. The secondary particles of the precursor are spherical, with a particle size of 10.113μm and a specific surface area of ​​9.97m 2 / g, tap density is 1.96g / cm 2 . Figure 3 The cross-sectional structure of the precursor of the positive electrode material containing molybdenum element prepared in Example 2 is shown, which has a sparse inner and dense outer structure, a high inner core roundness, and a uniform outer shell thickness.

[0202] Example 2 was prepared using a method similar to Example 1, except that:

[0203] The reaction time in the first coprecipitation reaction was 4.7 hours.

[0204] Example 3

[0205] A cathode material precursor containing molybdenum, wherein the molar ratio of Ni:Co:Mn in the precursor is 90.0:5.0:5.0, and the molybdenum content is 518ppm based on the overall mass of the precursor. The secondary particles of the precursor are spherical, with a particle size of 10.553μm and a specific surface area of ​​9.76m 2 / g, tap density is 2.02g / cm 2 .

[0206] Example 3 was prepared using a method similar to Example 1, except that:

[0207] A 6.6 g / L molybdenum trioxide solution was prepared, and the molybdenum content in the seed crystals was about 18000 ppm.

[0208] Example 4

[0209] A cathode material precursor containing molybdenum, wherein the molar ratio of Ni:Co:Mn in the precursor is 90.0:5.0:5.0, and the molybdenum content is 829ppm based on the overall mass of the precursor. The secondary particles of the precursor are spherical, with a particle size of 10.229μm and a specific surface area of ​​11.98m 2 / g, tap density is 21.98g / cm 2 .

[0210] Example 4 was prepared using a method similar to Example 1, except that:

[0211] An 8.1 g / L molybdenum trioxide solution was prepared, and the molybdenum content in the seed crystals was about 22000 ppm.

[0212] Example 5

[0213] A cathode material precursor containing molybdenum, with a chemical formula of Ni:Co:Mn in the precursor having a molar ratio of 83.0:7.0:10.0. Based on the overall mass of the precursor, the molybdenum content is approximately 622ppm. The secondary particles of the precursor are spherical, with a particle size of 10.535μm and a specific surface area of ​​10.02m 2 / g, tap density is 2.01g / cm 2 . Figure 4 The cross-sectional structure of the precursor of the positive electrode material containing molybdenum element prepared in Example 5 is shown, which has a sparse inner and dense outer structure, a high inner core roundness, and a uniform outer shell thickness.

[0214] Example 5 was prepared using a method similar to Example 1, except that:

[0215] In the weighing and liquid preparation step, the nickel sulfate solution, the cobalt sulfate solution, the manganese sulfate solution and pure water are mixed and stirred to prepare a metal salt solution according to a molar ratio of Ni:Co:Mn=83.0:7.0:10.0.

[0216] Example 6

[0217] A cathode material precursor containing molybdenum, with a chemical formula of Ni:Co:Mn in the precursor with a molar ratio of 96.0:3.0:1.0. Based on the overall mass of the precursor, the molybdenum content is approximately 621ppm. The secondary particles of the precursor are spherical, with a particle size of 10.369μm and a specific surface area of ​​10.02m 2 / g, tap density is 2.01g / cm 2 .

[0218] Example 6 was prepared using a method similar to Example 1, except that:

[0219] In the weighing and liquid preparation step, the nickel sulfate solution, the cobalt sulfate solution, the manganese sulfate solution and pure water are mixed and stirred to prepare a metal salt solution according to a molar ratio of Ni:Co:Mn=96.0:3.0:1.0.

[0220] Example 7

[0221] A cathode material precursor containing molybdenum, with a chemical formula of Ni:Co:Mn in the precursor with a molar ratio of 89.0:4.6:6.6. Based on the overall mass of the precursor, the molybdenum content is approximately 622ppm. The secondary particles of the precursor are spherical, with a particle size of 10.467μm and a specific surface area of ​​10.88m 2 / g, tap density is 1.98g / cm 2 .

[0222] Example 7 was prepared using a method similar to Example 1, except that:

[0223] In the weighing and liquid preparation step, the nickel sulfate solution, cobalt sulfate solution, manganese sulfate solution and pure water are mixed and stirred to prepare metal salt solution 1 according to a molar ratio of 83.0:7.0:10.0; the nickel sulfate solution, cobalt sulfate solution, manganese sulfate solution and pure water are mixed and stirred to prepare metal salt solution 2 according to a molar ratio of Ni:Co:Mn=90.0:5.0:5.0.

[0224] In the first coprecipitation reaction, metal salt solution 1 is introduced;

[0225] The metal salt solution 2 is introduced into the second coprecipitation reaction.

[0226] Comparative Example 1

[0227] A cathode material precursor with the chemical formula Ni 0.90 Co 0.07 Mn 0.03 (OH)2. Ni, Co, and Mn ions in the cathode material precursor are evenly distributed in the bulk of the material; the secondary particles of the cathode material precursor are spherical, with a particle size of 10.503 μm and a specific surface area of ​​10.46 m 2 / g, compacted density is 1.97g / cm 2 See Figure 5 The cross-sectional structure has a sparse inner and dense outer structure.

[0228] The preparation method of the positive electrode material precursor of Comparative Example 1 is specifically prepared by a one-step method according to the following steps:

[0229] Weigh and prepare the solution: Prepare appropriate amounts of 120g / L nickel sulfate solution, 120g / L cobalt sulfate solution, and 120g / L manganese sulfate solution. Mix the nickel sulfate solution, cobalt sulfate solution, manganese sulfate solution, and pure water until uniformly mixed. Prepare a metal salt solution with a molar ratio of Ni:Co:Mn = 90.0:7.0:3.0, where the sum of the nickel, cobalt, and manganese ion concentrations is 120g / L.

[0230] Preparation of base liquid: pure water, sodium hydroxide solution and ammonia solution were added into the reactor, and nitrogen was introduced as a protective gas to adjust the base liquid conditions to a pH value of 10.65 and a free ammonia concentration of 6.0 g / L.

[0231] Co-precipitation reaction: According to the set flow rate, metal salt solution, sodium hydroxide solution and ammonia water are introduced into the reactor to carry out co-precipitation reaction. The flow ratio of metal salt solution, sodium hydroxide solution and ammonia water is 1:0.36:0.04, the pH value is 10.65, the reaction temperature is 55℃, and the free ammonia concentration is 6.0g / L. After the reaction particle size reaches the requirement, the feeding is stopped. Then, Ni is washed, dried, sieved, demagnetized and packaged to obtain Ni 0.90 Co 0.07 Mn 0.03 (OH)2 precursor.

[0232] Comparative Example 2

[0233] A cathode material precursor with the chemical formula Ni 0.90 Co 0.05 Mn 0.05 (OH)2. In the cathode material precursor, Ni, Co, and Mn ions are evenly distributed in the bulk of the material; the secondary particles of the cathode material precursor are spherical, with a particle size of 10.030 μm and a specific surface area of ​​9.11 m 2 / g, compacted density is 1.98g / cm 2 See Figure 6 The cross-sectional structure has a sparse inner and dense outer structure.

[0234] The preparation method of the positive electrode material precursor of this embodiment is similar to that of Example 1, except that:

[0235] In the weighing and liquid preparation step, a molybdenum trioxide solution with a Mo ion concentration of 7.5 g / L was not prepared.

[0236] In the first base solution preparation step, the pH value was 11.30 and the free ammonia concentration was 3.0 g / L.

[0237] In the first coprecipitation reaction step, the flow ratio of the metal salt solution, the sodium hydroxide solution and the ammonia water is 1:0.39:0.04, the pH value is controlled at 11.30 from 0 to 1 hour; the pH value is controlled at 11.15 from 1 to 3 hours; the pH value is controlled at 10.95 from 3 to 5 hours; the pH value is controlled at 10.75 from 5 to 12 hours; the pH value is controlled at 10.55 from 12 to 14 hours; the pH value is controlled at 10.30 from 14 hours to the shutdown; the reaction temperature is 65°C, the free ammonia concentration is controlled at 3.0 g / L from 0 to 5 hours; and the free ammonia concentration is controlled at 2.5 g / L from 5 hours to the shutdown.

[0238] In the second base solution preparation step, the pH value was 10.40 and the free ammonia concentration was 4.0 g / L.

[0239] In the second coprecipitation reaction step, the flow ratio of the metal salt solution, the sodium hydroxide solution and the ammonia water is 1:0.37:0.035, the pH value is controlled at 10.40 from 0 to 11 hours; the pH value is controlled at 10.50 from 11 to 25 hours; the pH value is controlled at 10.40 from 25 hours to stopping the kettle; the reaction temperature is 60°C, the free ammonia concentration is controlled at 4.0 g / L from 0 to 5 hours; and the free ammonia concentration is controlled at 3.2 g / L from 5 hours to stopping the kettle.

[0240] Comparative Example 3

[0241] A cathode material precursor with the chemical formula Ni 0.92 Co 0.05 Mn 0.03 (OH)2. Ni, Co, and Mn ions in the cathode material precursor are evenly distributed in the bulk of the material; the secondary particles of the cathode material precursor are spherical, with a particle size of 13.326 μm and a specific surface area of ​​9.64 m 2 / g, compacted density is 2.01g / cm 2 See Figure 7 The cross-sectional structure has a sparse inner and dense outer structure.

[0242] Comparative Example 3 was prepared using a method similar to Example 1, except that:

[0243] In the weighing and liquid preparation step, a metal salt solution is prepared according to the molar ratio of Ni:Co:Mn=95.0:2.5:2.5, wherein the sum of the mass concentrations of nickel, cobalt, and manganese ions is 120 g / L.

[0244] In the first base solution preparation step, the pH value was 11.05 and the free ammonia concentration was 3.3 g / L.

[0245] In the first coprecipitation reaction step, the flow ratio of the metal salt solution, the sodium hydroxide solution and the ammonia water is 1:0.375:0.02, the pH value is controlled at 11.05 from 0 to 5 hours; the pH value is controlled at 10.90 from 5 to 7 hours; the pH value is controlled at 10.70 from 7 to 9 hours; the pH value is controlled at 10.50 from 9 to 10 hours; and the pH value is controlled at 10.35 from 10 hours to stopping the kettle; the reaction temperature is 50°C, and the free ammonia concentration is controlled at 3.3 g / L from 0 hours to stopping the kettle.

[0246] In the second base solution preparation step, the pH value was 10.45 and the free ammonia concentration was 4.2 g / L.

[0247] In the second coprecipitation reaction step, the flow ratio of the metal salt solution, the sodium hydroxide solution and the ammonia water is 1:0.37:0.03, the pH value is controlled at 10.45 from 0 to 1 hour; the pH value is controlled at 10.55 from 1 to 22 hours; the pH value is controlled at 10.65 from 22 to 36 hours; and the pH value is controlled at 10.70 after 36 hours of stopping the kettle. The reaction temperature is 55°C, the free ammonia concentration is controlled at 4.2 g / L from 0 to 39 hours; and the free ammonia concentration is controlled at 5.2 g / L after 39 hours of stopping the kettle.

[0248] Comparative Example 4

[0249] A cathode material precursor containing molybdenum, with a chemical formula of Ni:Co:Mn in the precursor having a molar ratio of 90.0:5.0:5.0. Based on the overall mass of the precursor, the molybdenum content is approximately 20,000 ppm. The secondary particles of the precursor are spherical, with a particle size of 11.035 μm and a specific surface area of ​​13.76 m 2 / g, tap density is 1.87g / cm 2 The positive electrode material precursor containing molybdenum element in this embodiment is prepared by the following steps:

[0250] Weighing and preparing the solution: Mix nickel sulfate solution, cobalt sulfate solution, manganese sulfate solution, and pure water until evenly distributed. Prepare a metal salt solution with a molar ratio of Ni:Co:Mn = 90.0:5.0:5.0, where the combined mass concentration of nickel, cobalt, and manganese ions is 120 g / L. Prepare a molybdenum trioxide solution with a Mo ion concentration of 7.5 g / L.

[0251] Preparation of the first base liquid: pure water, sodium hydroxide solution, and ammonia solution were added to the reaction kettle, and nitrogen was introduced as a protective gas. The pH value was adjusted to 11.45 and the free ammonia concentration was 4.0 g / L to obtain the first base liquid.

[0252] The first coprecipitation reaction: according to the set flow rate, the metal salt solution, molybdenum trioxide solution, sodium hydroxide solution and ammonia water are introduced into the reactor to carry out the coprecipitation reaction. The flow ratio of the metal salt solution, molybdenum trioxide solution, sodium hydroxide solution and ammonia water is 2:1:0.6:0.08. The pH value is controlled at 11.45 from 0 to 1 hour; the pH value is controlled at 11.25 from 1 to 6 hours; the pH value is controlled at 11.05 from 6 to 16 hours; the pH value is controlled at 10.85 from 16 to 40 hours; the pH value is controlled at 10.80 after stopping the reactor for 40 hours. The reaction temperature is 60°C. The free ammonia concentration is controlled at 4.0 g / L from 0 to 8 hours; the free ammonia concentration is controlled at 3.0 g / L after stopping the reactor for 8 hours. The reaction is carried out for 4 hours before the reactor is stopped and air is introduced for weak oxidation. When the particle size reaches the specified value, the feeding is stopped. The material in this stage is directly dried to obtain seed crystals.

[0253] Preparation of the second bottom liquid: pure water, ammonia solution, and seed crystals were added into the reactor, and nitrogen was introduced as a protective gas. The pH value was adjusted to 10.35 and the free ammonia concentration was 4.0 g / L to obtain the second bottom liquid.

[0254] Second coprecipitation reaction: A metal salt solution, sodium hydroxide solution, and aqueous ammonia were introduced into the reactor at set flow rates for a coprecipitation reaction. The flow ratio of the metal salt solution, molybdenum trioxide solution, sodium hydroxide solution, and aqueous ammonia was 1:0.5:0.36:0.03. The pH was controlled at 10.35 from 0 to 4 hours, 10.45 from 4 to 11 hours, 10.50 from 11 to 24 hours, and 10.40 after 24 hours of stopping the reactor. The reaction temperature was 57°C, and the free ammonia concentration was controlled at 4.0 g / L from 0 to 5 hours, and 3.3 g / L after 5 hours of stopping the reactor. Feeding was stopped when the reaction particle size reached the required value. The precursor was then washed, dried, sieved, demagnetized, and packaged.

[0255] Comparative Example 5

[0256] A cathode material precursor containing molybdenum, with a chemical formula of Ni:Co:Mn in the precursor with a molar ratio of 90.0:5.0:5.0. Based on the overall mass of the precursor, the molybdenum content is approximately 625ppm. The secondary particles of the precursor are spherical, with a particle size of 11.263μm and a specific surface area of ​​11.68m 2 / g, tap density is 1.93g / cm 2 .

[0257] Comparative Example 5 was prepared using a method similar to Comparative Example 4, except that:

[0258] Prepare a molybdenum trioxide solution with a Mo ion concentration of 0.75 g / L;

[0259] In the first coprecipitation reaction, the flow ratio of the metal salt solution, molybdenum trioxide solution, sodium hydroxide solution, and ammonia solution was 2:0.33:0.6:0.08;

[0260] In the second coprecipitation reaction, the flow ratio of the metal salt solution, molybdenum trioxide solution, sodium hydroxide solution and ammonia solution is 1:0.167:0.36:0.03.

[0261] Preparation of positive electrode materials

[0262] The present invention also provides a positive electrode material, the preparation method of which comprises the following steps:

[0263] 2 kg of the positive electrode material precursors prepared in the above Examples 1-7 and Comparative Examples 1-5 were mixed with LiOH in a molar ratio of 1:1.03 by a high-speed mixer, and sintered in a box furnace under an air atmosphere at a sintering temperature of 710° C. for 12 h. After cooling to room temperature, the mixture was crushed and sieved to obtain a positive electrode material.

[0264] The present invention also provides a lithium ion battery positive electrode sheet and a battery, and the preparation method thereof is as follows:

[0265] (1) Preparation of positive electrode: The lithium battery positive electrode materials corresponding to the above-prepared Examples 1-7 and Comparative Examples 1-5 were mixed with expanded graphite, carbonyl nickel powder and PTFE (polytetrafluoroethylene) in a mass ratio of 7:1:1:1 to form a slurry, applied on nickel foam, pressed by a roller press, dried and cut, and finally welded to the tabs and softened to obtain a positive electrode sheet;

[0266] (2) Preparation of negative electrode: AB5 alloy powder was directly pressed into shape by a roller press using a copper mesh as a carrier, cut and soaked in 15% PTFE + CMC (carboxymethyl cellulose) and then dried;

[0267] (3) Battery assembly: The prepared positive electrode sheet, negative electrode sheet and separator are wound into a battery core and then placed into a battery steel shell. Then, the core is rolled, sealed with sealing oil, welded with a battery cap and sealed with electrolyte. Finally, the battery assembly is completed by chemical sorting.

[0268] Test Case

[0269] The positive electrode material precursor containing molybdenum element prepared in the example, the positive electrode material precursor prepared in the comparative example, and the battery were subjected to physical and chemical data and electrochemical performance tests.

[0270] The particle size D50 of the secondary particles was measured by a laser particle size analyzer (instrument model: Mastersizer 3000) in accordance with the national standard GB / T 19077-2016 Particle size analysis by laser diffraction method.

[0271] Porosity Testing Method: Specific testing methods for the various porosities of secondary particles: Adjust a scanning electron microscope (SEM) to an appropriate magnification and photograph a cross-sectional SEM image of the cathode material precursor secondary particle. This cross-sectional SEM image is then analyzed using Image-Pro Plus software to calculate the various porosities. The calculation formulas are: Total Porosity = [(Sum of the Areas of the Pores in the Secondary Particles in the Cross-Section) / Cross-Sectional Area of ​​the Secondary Particles) × 100] (%); Core Porosity = [(Sum of the Areas of the Pores in the Inner Layer of the Secondary Particles in the Cross-Section) / Cross-Sectional Area of ​​the Inner Layer of the Secondary Particles in the Cross-Section) × 100] (%); Shell Porosity = [(Sum of the Areas of the Pores in the Outer Layer of the Secondary Particles in the Cross-Section) / Cross-Sectional Area of ​​the Outer Layer of the Secondary Particles in the Cross-Section) × 100] (%). For example, the magnification of the cross-sectional SEM image can be 7.0K, 9.0K, 10.0K, etc. The specific magnification is preferably such that only a single, complete or nearly complete, cross-section of the secondary particle sphere is visible in the SEM field of view.

[0272] Tap density test method: measured by powder tap density tester (model: Dandong Better BT-302), referring to the national standard "GB / T 5162-2021 Determination of tap density of metal powders";

[0273] Specific surface area was measured using a fully automated nitrogen adsorption surface area analyzer (BELPREP-VACII / BELSORP-MINI-X) in accordance with the national standard "GB / T 19587-2017 Determination of Specific Surface Area of ​​Solids by Gas Adsorption BET Method." The physical and chemical data of the cathode material precursors in Examples 1-7 and Comparative Examples 1-5 are shown in Table 1-2.

[0274] Table 1 Summary of some parameters of the precursors of the examples and comparative examples

[0275]

[0276] Table 2 Summary of some parameters of the precursors of the examples and comparative examples

[0277]

[0278] Electrochemical performance testing: Electrochemical performance testing was performed using a blue electric test system. The test voltage range was 2.5-4.3V, and 1C = 200mA / g. The test results of the button batteries prepared in Examples 1-7 and Comparative Examples 1-5 are shown in Table 3.

[0279] Table 3 Performance indicators of the positive electrode materials prepared from the precursors of the examples and comparative examples

[0280]

[0281]

[0282] Combine Figures 1 to 7 It can be seen from Tables 1 to 3 that when molybdenum is mainly distributed in the inner core and the precursor has a sparse inner and dense outer structure, the positive electrode material prepared therefrom has excellent rate and cycle performance while maintaining a relatively high capacity performance.

[0283] Furthermore, by comparing Examples 1-4 and Examples 5-6, it can be seen that improving the roundness of the core can further improve the rate and cycle performance of the product.

[0284] Further analysis of comparative examples 4-5 shows that when the doping amount in the precursor is too high, although it can improve the rate and cycle performance of the product to a certain extent, the excessive amount of doping elements has a greater negative impact on the battery capacity; when the doping amount in the precursor is too low, the effect of improving the cycle and rate is not obvious.

[0285] The above are only specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or replacements within the technical scope disclosed in this application, and such modifications or replacements are intended to be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be based on the scope of protection of the claims.

Claims

1. A cathode material precursor containing molybdenum, characterized in that: The positive electrode material precursor containing molybdenum comprises secondary particles having a core and an outer shell structure, wherein the molybdenum element is mainly distributed in the core of the secondary particles, and the content of the molybdenum element in the core is 18,000 to 22,000 ppm; The difference between the porosity of the inner core and the porosity of the outer shell is ≥18%.

2. The cathode material precursor containing molybdenum according to claim 1, characterized in that: The content of the molybdenum element in the precursor is 300-2000 ppm.

3. The cathode material precursor containing molybdenum according to claim 1 or 2, characterized in that: The chemical formula of the core is Ni x1 Co y1 Mn z1 Mo v1 M1 p1 (OH)2, where x1 + y1 + z1 + v1 + p1 = 1, 0.50 ≤ x1 < 1, 0 ≤ y1 ≤ 0.3, 0 < z1 ≤ 0.3, 0 ≤ p1 ≤ 0.1, and M1 is selected from one or more of W, Zr, Si, Mg, Al, B, Sr, Ti, Nb or Ta; optionally, 0.80 ≤ x1 < 1; and / or, The chemical formula of the outer shell is Ni x2 Co y2 Mn z2 M2 p2 (OH)2, where x2 + y2 + z2 + p2 = 1, 0.50 ≤ x2 < 1, 0 ≤ y2 ≤ 0.3, 0 < z2 ≤ 0.3, 0 ≤ p2 ≤ 0.1, and M2 is selected from one or more of W, Zr, Si, Mg, Al, B, Mo, Sr, Ti, Nb, or Ta; optionally, 0.80 ≤ x2 < 1.

4. The cathode material precursor containing molybdenum according to claim 1, characterized in that: The positive electrode material precursor containing molybdenum element meets at least one of the following conditions: (1) The roundness of the kernel is ≥90%; (2) the D50 of the precursor is 8.0 to 15.0 μm; (3) The specific surface area of ​​the precursor is 8-15m 2 / g; (4) The tap density of the precursor is ≥1.8 g / cm 3 ; (5) Thickness variance R of the shell 2 ≤0.1, optionally, R 2 ≤0.05; (6) The porosity of the inner core is 20-30%; (7) The porosity of the shell is 0.5 to 3%; (8) The porosity of the precursor is 1 to 5%; (9) The ratio of the cross-sectional area of ​​the inner core to the cross-sectional area of ​​the secondary particles is 5-15%; (10) The shell includes a plurality of primary particles, and the primary particles are radially arranged along the radial direction.

5. A method for preparing a cathode material precursor containing molybdenum, characterized in that: The steps include: Under an inert gas atmosphere, mixing a precipitant solution and a complexing agent solution to obtain a first base solution; First coprecipitation reaction: Under an inert gas atmosphere, the metal salt solution 1, the molybdenum-containing solution, the precipitant solution, and the complexing agent solution are introduced into the first base solution, and after a predetermined reaction time, the reaction is switched to an oxygen-containing atmosphere to obtain seed crystals; Under an inert gas atmosphere, mixing the seed crystals and the complexing agent solution to obtain a second base solution; Second coprecipitation reaction: Under an inert gas atmosphere, the metal salt solution 2, the precipitant solution and the complexing agent solution are introduced into the second base solution to react and obtain the positive electrode material precursor containing molybdenum element.

6. The method for preparing a cathode material precursor containing molybdenum according to claim 5, characterized in that: The preparation method satisfies at least one of the following conditions: (a) the pH of the first base solution is 11.40-11.65; (b) the concentration of the complexing agent in the first base solution is 3.8-5.2 g / L; (c) the pH of the first coprecipitation reaction is 10.70 to 11.60; (d) the concentration of the complexing agent during the first coprecipitation reaction is 3.0 to 4.5 g / L; (e) the temperature of the first coprecipitation reaction is 55-65° C.; (f) the pH of the second base solution is 10.30-10.55; (g) the concentration of the complexing agent in the second base solution is 3.8-5.2 g / L; (h) the pH of the second coprecipitation reaction is 10.30 to 10.65; (i) the concentration of the complexing agent during the second coprecipitation reaction is 3.0 to 4.5 g / L; (j) the temperature of the second coprecipitation reaction is 50-60° C.; (k) The preset time is 4-8 hours; (1) the second coprecipitation reaction is stopped after the D50 of the precipitate is 8-15 μm; (m) The preparation method further comprises post-processing the precipitate; optionally, the post-processing comprises solid-liquid separation, washing, and drying.

7. The method for preparing a cathode material precursor containing molybdenum according to claim 5 or 6, characterized in that: The preparation method satisfies at least one of the following conditions: (A) The metal salt solution 1 includes nickel ions and manganese ions, wherein the molar percentage of the nickel ions is 50%-100% based on the total amount of metal ions in the metal salt solution 1; optionally, the molar percentage of the nickel ions is 80%-100%; optionally, the metal salt solution 1 further includes cobalt ions; optionally, the metal salt solution further includes M1 ions, and the M1 is selected from one or more of W, Zr, Si, Mg, Al, B, Sr, Ti, Nb or Ta; (B) the concentration of metal ions in the metal salt solution 1 is 120 g / L to 240 g / L; (C) the precipitant solution is sodium hydroxide solution, potassium hydroxide solution or lithium hydroxide solution; (D) the complexing agent is aqueous ammonia; (E) the molybdenum-containing solution is a molybdenum trioxide solution; optionally, the concentration of the molybdenum-containing solution is 6.5-8.5 g / L; (F) During the first coprecipitation reaction, the flow ratio of the metal salt solution 1, the molybdenum-containing solution, the precipitant solution, and the complexing agent solution is 1.5-2.5:0.5-1.5:0.3-0.9:0.05-0.13; (G) The metal salt solution 2 includes nickel ions and manganese ions, wherein the amount of nickel ions is 50%-100% based on the total amount of metal ions in the metal salt solution 2; optionally, the amount of nickel ions is 80%-100%; optionally, the metal salt solution 2 further includes cobalt ions; optionally, the metal salt solution 2 further includes M2 ions, and the M2 is selected from one or more of W, Zr, Si, Mg, Al, B, Sr, Ti, Nb or Ta; (H) the concentration of metal ions in the metal salt solution 2 is 120 g / L to 240 g / L; (I) During the second coprecipitation reaction, the flow ratio of the metal salt solution 2, the precipitant solution, and the complexing agent solution is 0.5-1.5:0.26-0.46:0.02-0.

04.

8. A positive electrode material, characterized in that The cathode material precursor containing molybdenum element according to any one of claims 1 to 4 or the cathode material precursor containing molybdenum element prepared by the preparation method according to claims 5 to 7 is mixed with a lithium source and sintered.

9. A lithium-ion battery, characterized in that: Contains the positive electrode material according to claim 8.

10. An electrical equipment, characterized in that: A lithium-ion battery comprising the lithium-ion battery according to claim 9.

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