Lithium pre-embedded positive electrode material precursor, preparation method thereof and positive electrode material

Abstract

The invention provides a lithium pre-embedded positive electrode material precursor, a preparation method thereof and a positive electrode material. An X-ray powder diffraction pattern of the lithium pre-embedded positive electrode material precursor comprises the following characteristic peaks: F1: 14-16 degrees; f2: 21 DEG C to 22 DEG C; f3: 24 DEG C to 25 DEG C; f4: 25 DEG C to 27 DEG C; and F5: 30 DEG C to 33 DEG C. The lithium precursor meeting the characteristics is high in lithium ratio, the lithium element can fully participate in the reaction in the sintering process, the lithium element, nickel, manganese and other elements form a stable crystal structure, and the cycle performance of the material is improved. The lithium element is uniformly distributed in the precursor of the lithium pre-embedded positive electrode material, so that the diffusion rate of lithium ions in the material can be improved, the obstruction of ion migration is reduced, and the lithium pre-embedded positive electrode material has relatively good rate capability and cycle performance. When the precursor is sintered into the positive electrode material, further lithium mixing operation is not needed, and the preparation process is greatly simplified.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery positive electrode materials, and particularly relates to a pre-lithiated positive electrode material precursor, a preparation method thereof and a positive electrode material. BACKGROUND

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

[0003] As a key component of lithium ion batteries, the performance of the positive electrode material determines the overall performance of the battery to a great extent. The performance of the ternary positive electrode material precursor, as a key raw material of the positive electrode material, will directly determine the key physical and chemical indicators of the ternary positive electrode material. Therefore, developing high-performance positive electrode material precursors with excellent structures has become a research hotspot and key direction in the current lithium ion battery field. SUMMARY

[0004] To solve the above problems, the application provides a pre-lithiated positive electrode material precursor, a preparation method thereof and a positive electrode material, which can improve the diffusion rate of lithium ions in the material, reduce the hindrance of ion migration, and have good rate performance and cycle performance.

[0005] In a first aspect, the application provides a pre-lithiated positive electrode material precursor, and the X-ray powder diffraction pattern of the pre-lithiated positive electrode material precursor has characteristic peaks at the following positions: F1: 14°-16°; F2: 21°-22°; F3: 24°-25°; F4: 25°-27°; and F5: 30°-33°.

[0006] According to the embodiment of the first aspect of the application, the chemical formula of the pre-lithiated positive electrode material precursor is Li x MeB z wherein Me contains nickel and manganese, B contains CO3, 0.6≤x≤2.2, and 1.2≤z≤2.2.

[0007] According to an embodiment of the first aspect of the present application, the pre-lithium intercalation cathode material precursor further comprises a characteristic peak at 2-theta of 23°-24°, and / or 33°-34°, and / or 36.5°-37.5°, and / or 37.5°-38.5°, and / or 39.5°-40.5°, and / or 41.5°-42.5°, and / or 42.5°-43.5°, and / or 45°-46°, and / or 51°-53° in the X-ray powder diffraction pattern.

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

[0009] (1) The tap density of the pre-lithium intercalation cathode material precursor is 1.0-2.0 g / m 3 ; optionally, the tap density is 1.1-1.35 g / m 3 ;

[0010] (2) The specific surface area of the pre-lithium intercalation cathode material precursor is 30-100 m 2 / g;

[0011] (3) Li x MeB z , wherein Me further comprises one or more of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, Zn;

[0012] (4) Li x MeB z , wherein B further comprises one or more of OH, Cl, NO3, SO4, HCO3, H2PO4, HPO4, PO4;

[0013] (5) Li x MeB z , wherein 0.9≤x≤1.5, and optionally, 1.0≤x≤1.12;

[0014] (6) The pre-lithium intercalation cathode material precursor has characteristic peaks at 2-theta of F1: 15.00±0.20°, F2: 21.50±0.20°, F3: 24.70±0.20°, F4: 26.00±0.20°, and F5: 31.90±0.20° in the X-ray powder diffraction pattern.

[0015] (7) The X-ray powder diffraction pattern of the pre-lithiated cathode material precursor has characteristic peaks at 2-theta angles of 23.50±0.20°, and / or 29.50±0.20°, and / or 30.70±0.20°, and / or 33.70±0.20°, and / or 34.20±0.20°, and / or 37.00±0.20°, and / or 38.10±0.20°, and / or 40.00±0.20°, and / or 42.05±0.20°, and / or 43.06±0.20°, and / or 45.70±0.20°, and / or 52.70±0.20°, and / or 75.10±0.20°.

[0016] In a second aspect, the embodiments of the present application provide a preparation method of the pre-lithiated cathode material precursor of the first aspect, comprising: mixing a solution containing Li element and Me element with a carbonate solution to perform a co-precipitation reaction to obtain the pre-lithiated cathode material precursor under an inert gas atmosphere.

[0017] According to the embodiments of the second aspect of the present application, the preparation method satisfies one or more of the following conditions:

[0018] (1) The preparation method further comprises a solution preparation step, and the solution preparation comprises separately preparing a lithium salt solution, a Me salt solution and a carbonate solution; and / or the solution preparation comprises separately preparing a solution containing lithium salt and Me salt and a carbonate solution;

[0019] (2) The pH value at which the co-precipitation reaction is performed is 8.6-9.6;

[0020] (3) The temperature of the co-precipitation reaction is 45-65℃;

[0021] (4) The molar ratio of Li ion, Me ion and carbonate ion during the co-precipitation reaction is 1:(1.05-2.5):(1.5-3.0);

[0022] (5) The preparation method further comprises a post-treatment of the precipitate; and optionally, the post-treatment comprises solid-liquid separation, washing, drying and magnetic removal;

[0023] (6) The lithium salt is selected from one or more of lithium sulfate, lithium nitrate or lithium chloride;

[0024] (7) The Me salt contains a nickel salt and a manganese salt, and optionally, the Me salt further comprises one or more of a Co salt, an Al salt, a Na salt, a K salt, a Ca salt, a Sr salt, a Y salt, a Ti salt, a Zr salt, a Nb salt, a Sb salt, a Fe salt, a Cu salt, a Zn salt, and optionally, the nickel salt is selected from one or more of a sulfate, a nickel nitrate or a nickel chloride, and optionally, the manganese salt is selected from one or more of a manganese sulfate, a manganese nitrate or a manganese chloride;

[0025] (8) the carbonate salt is selected from one or more of lithium carbonate, sodium carbonate or potassium carbonate;

[0026] (9) the concentration of the carbonate salt solution is 2.0-5.0 mol / L;

[0027] (10) the concentration of lithium ions in the lithium salt solution is 2-5 mol / L;

[0028] (11) the concentration of Me ions in the Me salt solution is 1-3 mol / L;

[0029] (12) the concentration of lithium ions in the solution containing lithium salt and Me salt is 2-5 mol / L, and the concentration of Me ions is 1-3 mol / L;

[0030] (13) the mixing of the solution containing Li element and Me element with the carbonate salt solution is specifically mixing the lithium salt solution, the Me salt solution and the carbonate salt solution, or mixing the solution containing lithium salt and Me salt with the carbonate salt solution.

[0031] In a third aspect, the embodiments of the present application provide a pre-lithiated oxide precursor, characterized in that the chemical formula of the pre-lithiated oxide precursor is Li a MtC b wherein Mt contains nickel and manganese, C contains O, 0.6≤a≤2.2, 1.2≤b≤2.2; optionally, Mt further comprises one or more of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, Zn.

[0032] According to the embodiments of the third aspect of the present application, the pre-lithiated oxide precursor has characteristic peaks at the following positions in the X-ray powder diffraction spectrum: P1: 18-20°; P2: 21-22°; P3: 23-24°; P4: 36-38°; P5: 42-44°; P6: 44-46°; and / or Li a MtC b wherein 0.9≤a≤1.5; and / or Li a MtC b wherein 1.0≤a≤1.12.

[0033] In a fourth aspect, the embodiments of the present application provide a preparation method of the pre-lithiated oxide precursor of the third aspect, comprising the following steps: pre-sintering the pre-lithiated positive electrode material precursor of the first aspect or the pre-lithiated positive electrode material precursor prepared by the preparation method of the second aspect, optionally, the pre-sintering temperature is 500-800°C, optionally, the pre-sintering heating rate is 1-3°C / min, and the pre-sintering time is 8-15h.

[0034] Fifthly, embodiments of this application provide a cathode material, the raw materials of which include the pre-lithium-intercalated cathode material precursor of the first aspect of this application, or the pre-lithium-intercalated cathode material precursor prepared by the preparation method of the second aspect of this application, or the pre-lithium-intercalated oxide precursor of the third aspect of this application, or the pre-lithium-intercalated oxide precursor prepared by the preparation method of the fourth aspect of this application, and then sintered.

[0035] Sixthly, embodiments of this application provide a lithium-ion battery comprising the positive electrode material described in the fifth aspect of this application.

[0036] In a seventh aspect, this application provides an electrical device, including the lithium-ion battery described in the sixth aspect of this application.

[0037] The pre-lithium-intercalated cathode material precursor in this application embodiment includes the following characteristic peaks: F1: 14°~16°; F2: 21°~22°; F3: 24°~25°; F4: 25°~27°; F5: 30°~33°. Precursors satisfying these characteristics have a high lithium ratio, allowing lithium to fully participate in the reaction during sintering and form a stable crystal structure with elements such as nickel and manganese, thus improving the material's cycle performance. The uniform distribution of lithium in the pre-lithium-intercalated cathode material precursor can increase the diffusion rate of lithium ions in the material, reduce ion migration obstacles, and result in better rate performance and cycle performance. When sintering this precursor into a cathode material, no further lithium mixing is required, greatly simplifying the preparation process. Attached Figure Description

[0038] Figure 1 The XRD pattern of the pre-lithium-intercalated cathode material precursor provided in Example 1 of this application;

[0039] Figure 2 This is a SEM image of the pre-lithium-intercalated cathode material precursor provided in Example 1 of this application;

[0040] Figure 3 The XRD pattern of the pre-intercalated lithium oxide precursor provided in Example 1 of this application;

[0041] Figure 4 The XRD pattern of the cathode material provided in Example 1 of this application;

[0042] Figure 5 The XRD pattern of the pre-lithium-intercalated cathode material precursor provided in Example 2 of this application;

[0043] Figure 6 The XRD pattern of the pre-lithium-intercalated cathode material precursor provided in Example 3 of this application;

[0044] Figure 7 The XRD pattern of the cathode material precursor provided in Comparative Example 1 of this application;

[0045] Figure 8 The image shows the XRD pattern of the cathode material precursor provided in Comparative Example 2 of this application. Detailed Implementation

[0046] To make the purpose, technical solution, and beneficial technical effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the embodiments described in this specification are merely for explaining this application and are not intended to limit it.

[0047] For simplicity, this application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly stated; and any lower limit can be combined with other lower limits to form a range not explicitly stated, just as any upper limit can be combined with any other upper limit to form a range not explicitly stated. Furthermore, although not explicitly stated, every point or individual value between the endpoints of the range is included within that range. Therefore, each point or individual value can be used as its own lower or upper limit and combined with any other point or individual value or with other lower or upper limits to form a range not explicitly stated.

[0048] As used in this article:

[0049] In the description of this application, it should be noted that, unless otherwise stated, "above" and "below" include the stated number, and "multiple" in "one or more" means two or more.

[0050] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0051] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0052] "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).

[0053] In this application, particle size Dv50 and average particle size have the same meaning, referring to the particle size corresponding to the cumulative particle size distribution percentage of the pre-lithium-intercalated cathode material precursor reaching 50%.

[0054] In this application, the particle size distribution span is a parameter used to describe the breadth of the particle size distribution in a particle group. Its calculation formula is based on the cumulative distribution particle size, and is as follows: Particle size distribution span = (Dv90 - Dv10) / Dv50; where: Dv10: refers to the particle size at which 10% of the particles are smaller than this diameter (i.e., the particle size corresponding to 10% of the cumulative volume); Dv50: also known as the median particle size, refers to the particle size at which 50% of the particles are smaller than this diameter (the particle size corresponding to 50% of the cumulative volume); Dv90: refers to the particle size at which 90% of the particles are smaller than this diameter (the particle size corresponding to 90% of the cumulative volume). The specific values ​​of Dv10, Dv50, and Dv90 can be measured using a laser particle size analyzer.

[0055] This application provides a pre-lithium-intercalated cathode material precursor, its preparation method, and the cathode material, which has good rate performance and cycle performance.

[0056] In a first aspect, embodiments of this application provide a pre-lithium-intercalated cathode material precursor, wherein the 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor has characteristic peaks at the following positions: F1: 14°~16°; F2: 21°~22°; F3: 24°~25°; F4: 25°~27°; F5: 30°~33°.

[0057] The pre-lithium-intercalated cathode material precursor in this embodiment meets the aforementioned X-ray powder diffraction pattern characteristics, and the lithium element is uniformly distributed in the precursor. On the one hand, this avoids the problem of impurity phase formation due to local lithium excess or deficiency during the later sintering process in the prior art, forming a stable crystal structure with transition metal elements and improving the cycle performance of the material. On the other hand, the sintering process can increase the diffusion rate of lithium ions in the material, reduce the obstacle to ion migration, and allow lithium ions to fully participate in the reaction, thereby improving the rate performance of the material. At the same time, no further lithium mixing operation is required during the preparation process, which greatly simplifies the preparation process, and the resulting cathode material has low process cost and good product consistency.

[0058] The pre-lithium-intercalated cathode material precursor in this application embodiment satisfies the above-mentioned X-ray powder diffraction pattern characteristics, resulting in a low residual alkali content, complete crystal structure, no obvious impurity phase, low surface micro-powder degree, and I(003) / I(104) greater than 1.2, with a low degree of cation mixing, which is beneficial to improving the electrochemical performance of the cathode material.

[0059] In some embodiments, the chemical formula of the pre-lithium-intercalated cathode material precursor is Li x MeB z Where Me contains nickel and manganese, B contains CO3, 0.6≤x≤2.2, 1.2≤z≤2.2.

[0060] For example, the value of x can be any value among 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, and 2.2, or a range between any two.

[0061] For example, the value of z can be any value among 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1 and 2.2 or a range between any two.

[0062] In some embodiments, Li x MeB z In the case of 0.9 ≤ x ≤ 1.5.

[0063] In some embodiments, Li x MeB z In the equation 1.0 ≤ x ≤ 1.12.

[0064] For example, the value of x can be any value among 0.9, 1.0, 1.1, 1.2, 1.3, 1.4 and 1.5 or any value in between.

[0065] In some embodiments, the 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor further has characteristic peaks at the following positions: 23°–24°, and / or 33°–34°, and / or 36.5°–37.5°, and / or 37.5°–38.5°, and / or 39.5°–40.5°, and / or 41.5°–42.5°, and / or 42.5°–43.5°, and / or 45°–46°, and / or 51°–53°.

[0066] For example, the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor further includes the following characteristic peaks: 23°~24°, 33°~34°, 36.5°~37.5°, 37.5°~38.5°, 39.5°~40.5°, 41.5°~42.5°, 42.5°~43.5°, 45°~46°, and 51°~53°.

[0067] The pre-lithium-intercalated cathode material precursor with the above characteristics has phase structure stability, and can have good rate performance and cycle performance when it is used to form cathode material for batteries.

[0068] In some embodiments, the tap density of the pre-lithium-intercalated cathode material precursor is 1.0–2.0 g / m³. 3 .

[0069] For example, the tap density of the pre-lithium-intercalated cathode material precursor is 1.0 g / m³. 3 1.1g / m 3 1.2g / m 3 1.3g / m 3 1.4g / m 3 1.5g / m 3 1.6g / m 3 1.7g / m 3 1.8g / m 3 1.9g / m 3 and 2.0g / m 3 The value can be any value in the range or any value between the two. Optionally, the tapped density is 1.1 to 1.35 g / m³. 3 .

[0070] In some embodiments, the specific surface area of ​​the pre-lithium-intercalated cathode material precursor is 30–100 m². 2 / g.

[0071] For example, the specific surface area of ​​the pre-lithium-intercalated cathode material precursor is 30 m². 2 / g、35m 2 / g、40m 2 / g、45m 2 / g, 50m 2 / g、55m 2 / g、60m 2 / g、65m 2 / g、70m 2 / g、75m 2 / g、80m 2 / g、85m 2 / g、90m 2 / g、95m 2 / g and 100m 2Any value in / g or any range between the two.

[0072] A larger specific surface area means that the precursor particles have more surface active sites, which can promote atomic diffusion and migration during sintering. The specific surface area of ​​the pre-lithium-intercalated cathode material precursor in the embodiments of this application is within the above range, which provides favorable conditions for the precursor to form a single-crystal cathode material in the subsequent sintering process. The single-crystal cathode material has excellent cycle stability and structural stability, which can significantly improve the overall performance of lithium-ion batteries.

[0073] In some embodiments, Li x MeB z Me further includes one or more of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, and Zn.

[0074] In this embodiment of the application, Me is [Me1] b1 Me2 b2 Me3 b3 ...Men bn ], where Me1, Me2, Me3...Men are all different and are independently selected from one of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, Zn, and b1, b2, b3...bn are the same or different, and b1+b2+b3+...+bn=1.

[0075] In the embodiments of this application, Me in the pre-lithium-intercalated cathode material precursor may only include Mn and Ni elements, or it may include one or more of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, and Zn in addition to Mn and Ni elements.

[0076] For example, Me includes Mn, Ni, and Co elements; or Me includes Mn, Ni, Co, and Al elements; or Me includes Mn, Ni, Co, and Ti elements; or Me includes Mn, Ni, Co, Al, and Ti elements. Examples of these embodiments are not listed individually in this application.

[0077] In some embodiments, Li x MeB z In this context, B also includes one or more of the following: OH, Cl, NO3, SO4, HCO3, H2PO4, HPO4, and PO4.

[0078] In the embodiments of this application, B in the pre-lithium-intercalated cathode material precursor may only include CO3, or it may include one or more of OH, Cl, NO3, SO4, HCO3, H2PO4, HPO4, and PO4 in addition to CO3.

[0079] For example, B includes CO3; or B includes CO3 and OH; or B includes CO3 and Cl; or B includes CO3, Cl and OH. The embodiments of this application will not be listed one by one.

[0080] In some embodiments, the 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor has characteristic peaks at the following positions: F1: 15.00±0.20°, F2: 21.50±0.20°, F3: 24.70±0.20°, F4: 26.00±0.20° and F5: 31.90±0.20°.

[0081] In some embodiments, the 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor has characteristic peaks at the following positions: F1: 15.00±0.10°, F2: 21.50±0.10°, F3: 24.70±0.10°, F4: 26.00±0.10° and F5: 31.90±0.10°.

[0082] In some embodiments, the 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor has characteristic peaks at the following positions: 23.50±0.20°, and / or 29.50±0.20°, and / or 30.70±0.20°, and / or 33.70±0.20°, and / or 34.20±0.20°, and / or 37.00±0.20°, and / or 38.10±0.20°, and / or 40.00±0.20°, and / or 42.05±0.20°, and / or 43.06±0.20°, and / or 45.70±0.20°, and / or 52.70±0.20°, and / or 75.10±0.20°.

[0083] For example, the 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor further has characteristic peaks at the following positions: 23.50±0.20°, 29.50±0.20°, 30.70±0.20°, 33.70±0.20°, 34.20±0.20°, 37.00±0.20°, 38.10±0.20°, 40.00±0.20°, 42.05±0.20°, 43.06±0.20°, 45.70±0.20°, 52.70±0.20°, and 75.10±0.20°.

[0084] In some embodiments, the 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor further has characteristic peaks at the following positions: 23.50±0.10°, and / or 29.50±0.10°, and / or 30.70±0.10°, and / or 33.70±0.10°, and / or 34.20±0.10°, and / or 37.00±0.10°, and / or 38.10±0.10°, and / or 40.00±0.10°, and / or 42.05±0.10°, and / or 43.06±0.10°, and / or 45.70±0.10°, and / or 52.70±0.10°, and / or 75.10±0.10°.

[0085] Existing precursors usually need to be further mixed with lithium sources before sintering into cathode materials, which poses a risk of uneven mixing. This can easily lead to localized excess or deficiency of lithium, resulting in unstable material performance. In addition, the added lithium sources generally have a large particle size, about 10 μm, which is not conducive to lithium ion migration during the sintering reaction, resulting in poor sintering effect.

[0086] In view of this, in a second aspect, embodiments of this application provide a method for preparing a pre-lithium-intercalated cathode material precursor, comprising: mixing a solution containing Li and Me elements with a carbonate solution under an inert gas atmosphere to carry out a co-precipitation reaction to obtain the pre-lithium-intercalated cathode material precursor.

[0087] The preparation method of this application adopts a co-precipitation strategy to achieve uniform co-precipitation of lithium and Me elements in one step. Through the co-precipitation reaction, Li and Me elements are fully mixed in the solution and then precipitate together, avoiding the problem of uneven element distribution caused by subsequent batching / mixing processes in traditional processes. This ensures that the elements in the precursor are evenly distributed, laying the foundation for the subsequent preparation of high-performance cathode materials.

[0088] The preparation method of this application embodiment does not use complexing agents such as ammonia water in the precursor preparation process, does not generate ammonia nitrogen wastewater, has a simple process, is environmentally friendly, and is conducive to market promotion.

[0089] In the embodiments of this application, Me includes Mn and Ni.

[0090] In some embodiments, Me also includes one or more of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, and Zn.

[0091] The precursor of the first aspect of this invention was prepared by adjusting the ratio of each element in the solution containing Li and Me elements to the carbonate solution, the reaction temperature, the pH value, the stirring rate, and other process parameters.

[0092] In some embodiments, the preparation method further includes a solution preparation step, wherein the solution preparation includes preparing a lithium salt solution, a Me salt solution and a carbonate solution respectively; and / or the solution preparation includes preparing a solution containing lithium salt and Me salt and a carbonate solution respectively.

[0093] For example, lithium salt solutions and Me salt solutions can be prepared separately and placed in different containers; or lithium salt solutions and Me salt solutions can be prepared separately and placed in the same container.

[0094] In some embodiments, the coprecipitation reaction is carried out at a pH of 8.6 to 9.6.

[0095] For example, the pH of the coprecipitation reaction is any value of 8.6, 8.7, 8.8, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5 or 9.6 or a range between any two.

[0096] In some embodiments, the temperature of the coprecipitation reaction is 45–65°C.

[0097] For example, the temperature of the coprecipitation reaction is any value or a range between any two of 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, and 65°C.

[0098] In some embodiments, the molar ratio of Li ions, Me ions and carbonate ions during the coprecipitation reaction is 1:(1.05-2.5):(1.5-3.0).

[0099] For example, the molar ratio of Li ions, Me ions and carbonate ions in the coprecipitation reaction is 1:1.05:(1.5~3.0), 1:1.5:(1.5~3.0), 1:2:(1.5~3.0), 1:(1.05~2.5):1.5, 1:(1.05~2.5):2, 1:(1.05~2.5):2.5 or 1:(1.05~2.5):3.

[0100] In some embodiments, the preparation method further includes post-treatment of the precipitate; optionally, the post-treatment includes solid-liquid separation, washing, drying, and demagnetization.

[0101] For example, solid-liquid separation can be achieved through filtration.

[0102] For example, the washing process involves alternating between deionized water and ethanol for 3-5 times to ensure that the precipitate is thoroughly cleaned. The precipitate is then dried at 80-120°C for 12-24 hours to remove moisture and demagnetize, resulting in a pre-lithium-intercalated cathode material precursor.

[0103] In some embodiments, the lithium salt is selected from one or more of lithium sulfate, lithium nitrate, or lithium chloride.

[0104] In some embodiments, the Me salt comprises a nickel salt and a manganese salt.

[0105] Optionally, the nickel salt is selected from one or more of nickel sulfate, nickel nitrate, or nickel chloride. Exemplarily, the nickel salt includes nickel nitrate (Ni(NO3)2·6H2O), nickel sulfate (NiSO4·6H2O), nickel chloride (NiCl2·6H2O), or nickel acetate (Ni(CH3COO)2·4H2O), etc.

[0106] Optionally, the manganese salt is selected from one or more of manganese sulfate, manganese nitrate, or manganese chloride. Exemplarily, the manganese salt includes manganese nitrate (Mn(NO3)2·4H2O), manganese sulfate (MnSO4·H2O, MnSO4·5H2O), manganese chloride (MnCl2·4H2O), etc.

[0107] In some embodiments, the Me salt further includes one or more of the following: Co salt, Al salt, Na salt, K salt, Ca salt, Sr salt, Y salt, Ti salt, Zr salt, Nb salt, Sb salt, Fe salt, Cu salt, and Zn salt.

[0108] Optionally, the Co salt is selected from one or more of cobalt nitrate, cobalt sulfate, and cobalt chloride. For example, the Co salt includes cobalt nitrate (Co(NO3)2·6H2O), cobalt sulfate (CoSO4·7H2O), cobalt chloride (CoCl2·6H2O), etc.

[0109] Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, and Zn salts are soluble salts.

[0110] In some embodiments, the carbonate is selected from one or more of lithium carbonate, sodium carbonate, or potassium carbonate.

[0111] In some embodiments, the concentration of the carbonate solution is 2.0 mol / L to 5.0 mol / L.

[0112] For example, the concentration of the carbonate solution is any value or a range between any two of the following: 2.0 mol / L, 2.2 mol / L, 2.4 mol / L, 2.5 mol / L, 2.6 mol / L, 2.8 mol / L, 3.0 mol / L, 3.2 mol / L, 3.4 mol / L, 3.5 mol / L, 3.6 mol / L, 3.8 mol / L, 4.0 mol / L, 4.2 mol / L, 4.4 mol / L, 4.5 mol / L, 4.6 mol / L, 4.8 mol / L, and 5.0 mol / L.

[0113] In some embodiments, the lithium ion concentration in the lithium salt solution is 2 mol / L to 5 mol / L.

[0114] For example, the lithium ion concentration in the lithium salt solution is any value or a range between any two of the following: 2.0 mol / L, 2.2 mol / L, 2.4 mol / L, 2.5 mol / L, 2.6 mol / L, 2.8 mol / L, 3.0 mol / L, 3.2 mol / L, 3.4 mol / L, 3.5 mol / L, 3.6 mol / L, 3.8 mol / L, 4.0 mol / L, 4.2 mol / L, 4.4 mol / L, 4.5 mol / L, 4.6 mol / L, 4.8 mol / L, and 5.0 mol / L.

[0115] In some embodiments, the concentration of Me ions in the Me salt solution is 1 mol / L to 3 mol / L.

[0116] For example, the concentration of Me ions in the Me salt solution is any value or a range between any two of 1.0 mol / L, 1.2 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.8 mol / L, 2.0 mol / L, 2.2 mol / L, 2.4 mol / L, 2.5 mol / L, 2.6 mol / L, 2.8 mol / L, and 3.0 mol / L.

[0117] In some embodiments, the concentration of lithium ions in the solution containing lithium salt and Me salt is 2 mol / L to 5 mol / L, and the concentration of Me ions is 1 mol / L to 3 mol / L.

[0118] For example, the concentrations of lithium ions in solutions containing lithium salts and Me salts are 2.0 mol / L, 2.2 mol / L, 2.4 mol / L, 2.5 mol / L, 2.6 mol / L, 2.8 mol / L, 3.0 mol / L, 3.2 mol / L, 3.4 mol / L, 3.5 mol / L, 3.6 mol / L, 3.8 mol / L, 4.0 mol / L, 4.2 mol / L, 4.4 mol / L, 4.5 mol / L, and 4.6 mol / L. The concentration of Me ions is any value among 1.0 mol / L, 1.2 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.8 mol / L, 2.0 mol / L, 2.2 mol / L, 2.4 mol / L, 2.5 mol / L, 2.6 mol / L, 2.8 mol / L, and 3.0 mol / L, or ...

[0119] In some embodiments, mixing a solution containing Li and Me elements with a carbonate solution specifically involves mixing a lithium salt solution, a Me salt solution, and a carbonate solution, or mixing a solution containing lithium and Me salts with a carbonate solution.

[0120] Thirdly, embodiments of this application provide a pre-intercalated lithium oxide precursor, the chemical formula of which is Li a MtC b Mt contains nickel and manganese, C contains O, 0.6≤a≤2.2, 1.2≤b≤2.2.

[0121] For example, the value of a can be any value among 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1 and 2.2 or a range between any two.

[0122] In some embodiments, 0.9 ≤ a ≤ 1.5.

[0123] For example, the value of b can be any value among 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1 and 2.2 or a range between any two.

[0124] In some embodiments, Mt further includes one or more of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, and Zn. In the embodiments of this application, Mt is [Mt1] c1 Mt2 c2 Mt3 c3 ...Mtn cn ], where Mt1, Mt2, Mt3......Mtn are all different and are independently selected from one of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, Zn, and c1, c2, c3......cn are the same or different, and c1+c2+c3+......+cn=1.

[0125] In some embodiments, the 2θ angle of the X-ray powder diffraction pattern of the pre-intercalated lithium oxide cathode material precursor has a characteristic peak at the following positions:

[0126] P1: 18°~20°; P2: 21°~22°; P3: 23°~24°; P4: 36°~38°; P5: 42°~44°; P6: 44°~46°.

[0127] Fourthly, embodiments of this application provide a method for preparing a pre-intercalated lithium oxide precursor, comprising pre-sintering the pre-intercalated lithium cathode material precursor prepared by the method of the first aspect or the method of the second aspect. Optionally, the pre-sintering temperature is 500-800℃, the pre-sintering heating rate is 1-3℃ / min, and the pre-sintering time is 8-15h.

[0128] In some embodiments, the pre-sintering temperature is 500-800°C.

[0129] For example, the pre-sintering temperature is any value or a range between any two of 500°C, 520°C, 540°C, 550°C, 560°C, 580°C, 600°C, 620°C, 640°C, 650°C, 660°C, 680°C, 700°C, 720°C, 740°C, 750°C, 760°C, 780°C, and 800°C.

[0130] In some embodiments, the pre-lithium-intercalated oxide precursor of the third aspect of this application is prepared by pre-sintering the pre-lithium-intercalated cathode material precursor in the first aspect of this application or the pre-lithium-intercalated cathode material precursor prepared by the preparation method of the second aspect of this application.

[0131] In some embodiments, the pre-sintering heating rate is 1–3 °C / min, and the pre-sintering time is 8–15 h.

[0132] For example, the heating rate of the pre-sintering is any value or a range between any two of 1℃ / min, 1.2℃ / min, 1.4℃ / min, 1.5℃ / min, 1.6℃ / min, 1.8℃ / min, 2℃ / min, 2.2℃ / min, 2.4℃ / min, 2.5℃ / min, 2.6℃ / min, 2.8℃ / min, and 3℃ / min.

[0133] For example, the pre-sintering time is any value or a range between any two of 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, 14h, 14.5h and 15h.

[0134] Fifthly, embodiments of this application provide a cathode material, which is prepared by sintering a pre-lithium-intercalated cathode material precursor obtained by the preparation method of the first aspect of this application, or a pre-lithium-intercalated oxide precursor obtained by the preparation method of the second aspect of this application, or a pre-lithium-intercalated oxide precursor obtained by the preparation method of the third aspect of this application, or a pre-lithium-intercalated oxide precursor obtained by the preparation method of the fourth aspect of this application.

[0135] In some embodiments, the sintering temperature is 810℃~900℃ and the sintering time is 8h~15h.

[0136] For example, the sintering temperature is any value or a range between any two of 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C, and 900°C.

[0137] For example, the sintering time is any value or a range between any two of 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, 14h, 14.5h and 15h.

[0138] Sixthly, embodiments of this application provide a lithium-ion battery comprising the positive electrode material described in the fifth aspect of this application.

[0139] The lithium-ion battery provided in this application embodiment includes the above-mentioned positive electrode material, which enables the battery to have high capacity, good cycle and rate performance.

[0140] In some embodiments, the positive electrode material, conductive carbon black, and binder can be mixed into a slurry and coated onto the current collector to form a positive electrode sheet. Exemplarily, the current collector is aluminum foil.

[0141] Understandably, lithium-ion batteries also include negative electrode plates, separators, and electrolytes.

[0142] The specific composition and structure of the negative electrode sheet can be selected according to the type of lithium-ion battery, and the embodiments of this application are not limited in this regard.

[0143] In some embodiments, the separator may be a diaphragm. This application does not impose any particular limitation on the type of diaphragm; any known porous diaphragm with good chemical and mechanical stability may be selected.

[0144] 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.

[0145] Electrolytes can be liquid, gel, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0146] In some embodiments, the electrolyte salt may 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 difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0147] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents 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, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0148] In a seventh aspect, this application provides an electrical device, including the lithium-ion battery described in the sixth aspect of this application.

[0149] Example

[0150] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on weight, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0151] Example 1:

[0152] This embodiment provides a pre-lithium-intercalated cathode material precursor with the chemical formula Li. 1.076 Ni 0.6 Co 0.1 Mn 0.3 (CO3) 1.538 The secondary particles are nearly spherical with a Dv50 of 4.679 μm. Ni, Co, Mn, and Li are uniformly distributed throughout the material. The specific surface area of ​​the secondary particles is 58.94 m². 2 / g.

[0153] The preparation method of the pre-lithium-intercalated cathode material precursor in this embodiment includes the following steps:

[0154] Solution preparation: Dissolve nickel sulfate, cobalt sulfate, manganese sulfate, and lithium sulfate crystals to prepare a solution containing nickel sulfate, cobalt sulfate, manganese sulfate, and lithium sulfate. The lithium ion content in the solution is 2.5 mol / L, and the total nickel, cobalt, and manganese ion content is 2.0 mol / L. The molar ratio of the elements is Ni:Co:Mn = 60:10:30. Dissolve sodium carbonate crystals to prepare a 3.0 mol / L sodium carbonate solution.

[0155] Under an inert gas atmosphere: pure water is added to the reactor, nitrogen is introduced as a protective gas, the temperature is controlled at 50℃, and the reaction speed is 800 r / min;

[0156] Reaction process: Under stirring, the feed is pumped into the reactor at a set flow rate. The flow rate of the mixed metal salt solution is 3.0% / h of the available reactor volume, and the flow rate of the sodium carbonate solution is 3.5% / h of the available reactor volume for co-precipitation reaction. When the reaction slurry reaches the upper limit of the reactor volume, the mother liquor is discharged through a concentration device. The discharge rate of the mother liquor is consistent with the total feed rate. The pH value of the reaction is controlled between 9.2 and 9.3. The reaction is stopped when the particle size Dv50 of the material meets the requirements.

[0157] Post-processing steps: After the synthesis stage is completed, the materials are washed, dried, sieved, and demagnetized to obtain the target precursor.

[0158] This embodiment also provides a pre-lithium oxide intercalation precursor, the preparation method of which includes the following steps:

[0159] Two kilograms of the pre-lithium-intercalated cathode material precursor prepared above were sintered in an air atmosphere using a box furnace at a sintering temperature of 800°C for 10 hours. After cooling to room temperature, the precursor was pulverized and sieved to obtain a lithium oxide precursor.

[0160] This embodiment also provides a cathode material, the preparation method of which includes the following steps:

[0161] Two kg of the pre-lithium-intercalated cathode material precursor prepared above was sintered in an air atmosphere using a box furnace at a sintering temperature of 850℃ for 10 hours. After cooling to room temperature, it was pulverized and sieved to obtain the cathode material. XRD testing showed that the I003 / I104 ratio of the cathode material was 1.57.

[0162] Example 2

[0163] This embodiment provides a pre-lithium-intercalated cathode material precursor with the chemical formula Li. 1.102 Ni 0.59 Co 0.095 Mn 0.315 (CO3) 1.551The secondary particles are nearly spherical with a particle size of 4.481 μm. Ni, Co, Mn, and Li are uniformly distributed throughout the material. The specific surface area of ​​the secondary particles is 57.22 m². 2 / g.

[0164] Example 2 was prepared using a method similar to that of Example 1, except that:

[0165] (1) In the solution preparation step, a solution containing nickel sulfate, cobalt sulfate, manganese sulfate and lithium sulfate is prepared. The lithium ion content in the solution is 3.0 mol / L, the total content of nickel, cobalt and manganese ions is 2.0 mol / L, and the element ratio Ni:Co:Mn=59:9.5:31.5;

[0166] (2) In the reaction process, the flow rate of the mixed metal salt solution is 2.0% / h of the available volume of the reactor, and the flow rate of the sodium carbonate solution is 2.5% / h of the available volume of the reactor; the pH value of the reaction is controlled between 8.6 and 8.7.

[0167] This embodiment also provides a positive electrode material, which is prepared using a method similar to that in Example 1, except that the high-temperature sintering time is 12 hours.

[0168] Example 3

[0169] This embodiment provides a pre-lithium-intercalated cathode material precursor with the chemical formula Li. 1.076 Ni 0.6 Co 0.1 Mn 0.3 (CO3) 1.538 The secondary particles are nearly spherical with a particle size of 7.847 μm. Ni, Co, Mn, and Li are uniformly distributed throughout the material. The specific surface area of ​​the secondary particles is 55.07 m². 2 / g.

[0170] Example 3 was prepared using a method similar to that of Example 1, except that:

[0171] (1) In the reaction process, the flow rate of the mixed metal salt solution is 4.0% / h of the available volume of the reactor, and the flow rate of the sodium carbonate solution is 4.7% / h of the available volume of the reactor.

[0172] This embodiment also provides a positive electrode material, which is prepared using a method similar to that in Example 1, except that the sintering temperature is 860°C.

[0173] Example 4

[0174] This embodiment provides a pre-lithium-intercalated cathode material precursor with the chemical formula Li. 1.077 Ni 0.605 Co0.095 Mn 0.3 (CO3) 1.539 The secondary particles are nearly spherical with a particle size of 10.355 μm. Ni, Co, Mn, and Li are uniformly distributed throughout the material. The specific surface area of ​​the secondary particles is 45.62 m². 2 / g.

[0175] Example 4 was prepared using a method similar to that of Example 1, except that:

[0176] (1) In the solution preparation step, a solution containing nickel sulfate, cobalt sulfate, manganese sulfate and lithium sulfate is prepared. The lithium ion content in the solution is 2.8 mol / L, the total content of nickel, cobalt and manganese ions is 2.0 mol / L, and the element ratio Ni:Co:Mn = 60.5:9.5:30; sodium carbonate crystals are dissolved to prepare a 4.0 mol / L sodium carbonate solution.

[0177] (2) In the reaction process, the flow rate of the mixed metal salt solution is 5.0% / h of the available volume of the reactor, and the flow rate of the sodium carbonate solution is 4.5% / h of the available volume of the reactor.

[0178] This embodiment also provides a positive electrode material, which is prepared using a method similar to that in Example 1, except that the sintering temperature is 880°C.

[0179] Example 5

[0180] This embodiment provides a pre-lithium-intercalated cathode material precursor with the chemical formula Li. 1.059 Ni 0.6 Co 0.1 Mn 0.3 (CO3) 1.530 The secondary particles are nearly spherical with a particle size of 4.350 μm. Ni, Co, Mn, and Li are uniformly distributed throughout the material. The specific surface area of ​​the secondary particles is 73.48 m². 2 / g.

[0181] Example 5 was prepared using a method similar to that of Example 1, except that:

[0182] (1) In the solution preparation step, a solution containing nickel sulfate, cobalt sulfate, manganese sulfate and lithium sulfate is prepared. The lithium ion content in the solution is 2.8 mol / L, the total content of nickel, cobalt and manganese ions is 2.0 mol / L, and the element ratio Ni:Co:Mn=60:10:30; sodium carbonate crystals are dissolved to prepare a 3.0 mol / L sodium carbonate solution.

[0183] (2) In the reaction process, the flow rate of the mixed metal salt solution is 4.0% / h of the available volume of the reactor, and the flow rate of the sodium carbonate solution is 4.5% / h of the available volume of the reactor; the pH value of the reaction is controlled between 8.8 and 8.9.

[0184] This embodiment also provides a positive electrode material, which is prepared using the same method as in Example 1.

[0185] Comparative Example 1

[0186] This comparative example provides a carbonate cathode material precursor with the chemical formula Ni. 0.60 Co 0.10 Mn 0.3 The CO3 secondary particles are nearly spherical with a particle size of 4.362 μm. Ni, Co, and Mn are uniformly distributed in the material, and the specific surface area of ​​the secondary particles is 40.26 m². 2 / g.

[0187] Comparative Example 1 was prepared using a method similar to that of Example 1, except that:

[0188] (1) In the solution preparation step, a solution containing nickel sulfate, cobalt sulfate and manganese sulfate is prepared and combined to form a metal solution with a total metal content of 2 mol / L and an element ratio of Ni:Co:Mn = 60:10:30; sodium carbonate crystals are dissolved to prepare a 4.3 mol / L sodium carbonate solution;

[0189] (2) Control the pH value of the reaction between 8.0 and 8.5.

[0190] This comparative example also provides a cathode material, prepared using the following method:

[0191] Lithium carbonate and a comparative precursor were mixed uniformly in a high-speed mixer at a total metal content: lithium ratio of 1:1.05, and sintered at 850°C for 12 hours to obtain the cathode material.

[0192] Comparative Example 2

[0193] This embodiment provides a cathode material precursor with the chemical formula Li. 0.572 Ni 0.60 Co 0.1 Mn 0.30 (CO3) 1.286 The secondary particles are spherical with a particle size of 5.512 μm. Ni, Co, Mn and Li are uniformly distributed in the material.

[0194] Comparative Example 2 was prepared using a method similar to that of Example 1, except that:

[0195] (1) In the solution preparation step, a solution containing nickel sulfate, cobalt sulfate, manganese sulfate and lithium sulfate is prepared. The lithium ion content in the solution is 2.1 mol / L, the total content of nickel, cobalt and manganese ions is 2.0 mol / L, and the element ratio Ni:Co:Mn=60:10:30; sodium carbonate crystals are dissolved to prepare a 4.0 mol / L sodium carbonate solution.

[0196] (2) In the reaction process, the flow rate of the mixed metal salt solution is 3.0% / h of the available volume of the reactor, and the flow rate of the sodium carbonate solution is 1.8% / h of the available volume of the reactor; the pH value of the reaction is controlled between 7.5 and 8.5.

[0197] Test case

[0198] The physicochemical data and electrochemical performance of the pre-lithium-intercalated oxygen-containing cathode material precursor prepared in the examples, the cathode material precursor prepared in the comparative examples, and the battery were tested.

[0199] The particle size D of secondary particles V 50: Measured using a laser particle size analyzer (instrument model: Mastersizer3000), referring to the national standard GB / T 19077-2016 Particle size analysis by laser diffraction.

[0200] Tap density test method: The tap density was determined by a powder tap density tester (model: Dandong Baite BT-302) in accordance with the national standard GB / T 5162-2021 Determination of tap density of metal powders.

[0201] Specific surface area test method: The specific surface area was determined by a fully automated nitrogen adsorption specific surface area analyzer (instrument model: BELPREP-VACII / BELSORP-MINI-X) in accordance with the national standard GB / T 19587-2017 "Determination of specific surface area of ​​solid substances by gas adsorption BET method".

[0202] XRD testing method: X-ray diffraction parameters are as follows: Radiation source: CuK rays (1.54059 Å); Scanning mode: Scanning speed is 8° / min, step angle is 0.02°, Solar slit is 5°; Measurement range: 2θ = 5°~80°.

[0203] Electrochemical performance testing: The positive electrode materials obtained in the above examples and comparative examples were mixed with conductive carbon black and binder PVDF (polyvinylidene fluoride) in a vacuum glove box at a mass ratio of 8:1:1 to form a slurry, which was then coated on aluminum foil to form a positive electrode sheet. The negative electrode sheet was made of lithium metal sheet, and the electrolyte was 1 mol / L LiPF6 / EC:DMC (volume ratio 1:1). The battery case, positive and negative electrode sheets, separator, spring sheet, and gasket were assembled into a button battery in a vacuum glove box.

[0204] Electrochemical performance was tested using the Blue Electricity testing system at 25°C and 2.8–4.3 V, with 1C = 210 mA / g. The test results for the button batteries prepared in Examples 1–6 and Comparative Examples 1–2 are shown in Table 1.

[0205] Table 1 Comparison of electrochemical data of cathode materials prepared in the examples and comparative examples.

[0206]

[0207] Combination Figures 1 to 8 As shown in Table 1, the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor in the embodiments of this application includes the following characteristic peaks: F1: 14°~16°; F2: 21°~22°; F3: 24°~25°; F4: 25°~27°; F5: 30°~33°. The cathode material prepared from it has excellent capacity, rate capability and cycle performance.

[0208] After sintering, the cathode material in Example 1 has a low degree of micronization on its surface and a near-ideal layered structure with low lattice distortion and low cation mixing. Compared to Comparative Example 1 (rear-end lithium mixing), which has a similar lithium ratio, the rate performance of Example 1 is improved due to the more uniform distribution of lithium. Comparative Example 2 has a low lithium content, deteriorated structure, and its electrochemical performance is significantly reduced.

[0209] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A precursor for a pre-lithium-intercalated cathode material, characterized in that, The X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor has a characteristic peak at the 2θ angle at the following positions: F1:14°～16°； F2:21°～22°； F3:24°～25°； F4:25°～27°； F5:30°～33°。 2. The pre-lithium-intercalated cathode material precursor according to claim 1, characterized in that, The chemical formula of the pre-lithium-intercalated cathode material precursor is Li. x MeB z ; where Me contains nickel and manganese; B contains CO3; 0.6≤x≤2.2, 1.2≤z≤2.

2.

3. The pre-lithium-intercalated cathode material precursor according to claim 1, characterized in that, The 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor further exhibits characteristic peaks at the following positions: 23°–24°, and / or 33°–34°, and / or 36.5°–37.5°, and / or 37.5°–38.5°, and / or 39.5°–40.5°, and / or 41.5°–42.5°, and / or 42.5°–43.5°, and / or 45°–46°, and / or 51°–53°.

4. The pre-lithium-intercalated cathode material precursor according to claim 1 or 2, characterized in that, The pre-lithium-intercalated cathode material precursor satisfies at least one of the following conditions: (1) The tap density of the pre-lithium-intercalated cathode material precursor is 1.0–2.0 g / m³. 3 Optionally, the tap density is 1.1–1.35 g / m³. 3 ; (2) The specific surface area of ​​the pre-lithium-intercalated cathode material precursor is 30-100 m². 2 / g; (3) The Li x MeB z Me also includes one or more of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, and Zn; (4) The Li x MeB z In this context, B also includes one or more of the following: OH, Cl, NO3, SO4, HCO3, H2PO4, HPO4, and PO4. (5) The Li x MeB z In the given condition, 0.9 ≤ x ≤ 1.5, and optionally, 1.0 ≤ x ≤ 1.12; (6) The 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor has characteristic peaks at the following positions: F1: 15.00±0.20°, F2: 21.50±0.20°, F3: 24.70±0.20°, F4: 26.00±0.20° and F5: 31.90±0.20°; (7) The 2θ angle of the X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor has characteristic peaks at the following positions: 23.50±0.20°, and / or 29.50±0.20°, and / or 30.70±0.20°, and / or 33.70±0.20°, and / or 34.20±0.20°, and / or 37.00±0.20°, and / or 38.10±0.20°, and / or 40.00±0.20°, and / or 42.05±0.20°, and / or 43.06±0.20°, and / or 45.70±0.20°, and / or 52.70±0.20°, and / or 75.10±0.20°.

5. A method for preparing a pre-lithium-intercalated cathode material precursor according to any one of claims 1-4, characterized in that, include: In an inert gas atmosphere, a solution containing Li and Me elements is mixed with a carbonate solution to undergo a co-precipitation reaction to obtain a precursor for a pre-lithium-intercalated cathode material.

6. The preparation method according to claim 5, characterized in that, The preparation method satisfies one or more of the following conditions: (1) The preparation method further includes a solution preparation step, wherein the solution preparation includes preparing a lithium salt solution, a Me salt solution and a carbonate solution respectively; and / or the solution preparation includes preparing a solution containing lithium salt and Me salt and a carbonate solution respectively; (2) The pH value at which the coprecipitation reaction takes place is 8.6–9.6; (3) The temperature of the coprecipitation reaction is 45-65℃; (4) The molar ratio of Li ions, Me ions and carbonate ions in the coprecipitation reaction is 1:(1.05~2.5):(1.5~3.0); (5) The preparation method further includes post-treatment of the precipitate; optionally, the post-treatment includes solid-liquid separation, washing, drying, and demagnetization; (6) The lithium salt is selected from one or more of lithium sulfate, lithium nitrate or lithium chloride; (7) The Me salt comprises nickel salt and manganese salt. Optionally, the Me salt further comprises one or more of Co salt, Al salt, Na salt, K salt, Ca salt, Sr salt, Y salt, Ti salt, Zr salt, Nb salt, Sb salt, Fe salt, Cu salt, and Zn salt. Optionally, the nickel salt is selected from one or more of sulfate, nickel nitrate, or nickel chloride. Optionally, the manganese salt is selected from one or more of manganese sulfate, manganese nitrate, or manganese chloride. (8) The carbonate is selected from one or more of lithium carbonate, sodium carbonate or potassium carbonate; (9) The concentration of the carbonate solution is 2.0 mol / L to 5.0 mol / L; (10) The lithium ion concentration in the lithium salt solution is 2 mol / L to 5 mol / L; (11) The concentration of Me ions in the Me salt solution is 1 mol / L to 3 mol / L; (12) The concentration of lithium ions in the solution containing lithium salt and Me salt is 2 mol / L to 5 mol / L, and the concentration of Me ions is 1 mol / L to 3 mol / L. (13) The specific operation of mixing the solution containing Li and Me elements with the carbonate solution is to mix the lithium salt solution, the Me salt solution and the carbonate solution, or to mix the solution containing lithium salt and Me salt with the carbonate solution.

7. A pre-intercalated lithium oxide precursor, characterized in that, The chemical formula of the pre-lithium oxide embedded precursor is Li a MtC b Mt contains nickel and manganese, C contains O, 0.6≤a≤2.2, 1.2≤b≤2.2; Optionally, the Mt further includes one or more of Co, Al, Na, K, Ca, Sr, Y, Ti, Zr, Nb, Sb, Fe, Cu, and Zn.

8. The pre-intercalated lithium oxide precursor according to claim 7, characterized in that, The X-ray powder diffraction pattern of the pre-lithium-intercalated cathode material precursor has a characteristic peak at the 2θ angle at the following positions: P1:18°~20°; P2:21°~22°; P3:23°~24°; P4:36°~38°; P5:42°~44°; P6:44°~46°; and / or Li a MtC b In the given condition, 0.9 ≤ a ≤ 1.5; and / or Li a MtC b In the equation, 1.0 ≤ a ≤ 1.

12.

9. The method for preparing the pre-lithium-intercalated oxide precursor according to claim 7 or 8, characterized in that, This includes pre-sintering treatment of the pre-lithium-intercalated cathode material precursor as described in any one of claims 1-4 or the pre-lithium-intercalated cathode material precursor prepared by the preparation method described in any one of claims 5-6; Optionally, the pre-sintering temperature is 500-800℃; Optionally, the heating rate of the pre-sintering is 1 to 3 °C / min; Optionally, the pre-sintering time is 8 to 15 hours.

10. A positive electrode material, characterized in that, The raw materials include the pre-lithium-intercalated cathode material precursor according to any one of claims 1-4, or the pre-lithium-intercalated cathode material precursor prepared by the preparation method according to claim 5 or 6, or the pre-lithium-intercalated oxide precursor according to claim 7 or 8, or the pre-lithium-intercalated oxide precursor prepared by the preparation method according to claim 9.

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