Lithium-rich manganese-based positive electrode material and battery

Abstract

The invention provides a lithium-rich manganese-based positive electrode material and a battery, the lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based positive electrode material matrix, and the chemical formula of the lithium-rich manganese-based positive electrode material matrix is x (Li2MnO3). Y (LiNiaCobMncMdQeAkO2), wherein 0 < x < 1, 0 < y < 1, x + y = 1, 0.05 < = a < = 0.7, 0 < b < = 0.6, 0.01 < = c < = 0.8, 0 < d < = 0.1, 0 < e < = 0.1, 0 < = k < = 0.05, and A comprises at least one of La, Ce, Sm and Y; the ion radius of M is greater than or equal to 135pm, and the ion electronegativity is 0.79-0.9; the ionic radius of Q is 54 to 80 pm, and the ionic electronegativity is 1.3 to 2.1. According to the lithium-rich manganese-based positive electrode material provided by the invention, the specific capacity, the cycle performance and the rate capability of the battery can be improved.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, and particularly relates to a lithium-rich manganese-based cathode material and battery. Background Technology

[0002] As a highly efficient and clean energy storage and conversion medium, the application of rechargeable batteries has expanded from consumer electronics to key industries such as electric vehicles, smart grids, and large-scale energy storage systems. With the advancement of global energy structure transformation and carbon neutrality goals, the market has placed higher comprehensive demands on the energy density, cycle life, and power characteristics of rechargeable batteries, driving battery technology to continuously develop towards higher performance.

[0003] Lithium-rich manganese-based cathode materials are considered a candidate material for next-generation high-energy-density lithium-ion batteries due to their high theoretical energy density, relatively low cost, and environmental friendliness. Based on a synergistic redox reaction mechanism between anions and cations, this material can achieve a discharge specific capacity far exceeding that of traditional layered materials, demonstrating great potential to break through existing energy density bottlenecks. However, lithium-rich manganese-based cathode materials still face significant challenges in practical applications: First, their initial coulombic efficiency is relatively low, and at high operating voltages, irreversible phase transitions and oxygen loss in the material structure are severe, leading to rapid capacity decay during cycling and making it difficult to meet long-term usage requirements in terms of cycle stability; second, the material itself has low electronic conductivity and lithium-ion diffusion coefficient, resulting in poor rate performance and an inability to support rapid charge and discharge; simultaneously, voltage decay and other issues also restrict the full realization of their energy density.

[0004] These combined shortcomings in specific capacity, long cycle life, and high-rate performance have limited the commercial application of this material. Summary of the Invention

[0005] The main objective of this invention is to provide a lithium-rich manganese-based cathode material, which, when applied to batteries, can improve the specific capacity, rate performance, and cycle performance of the batteries.

[0006] The present invention also provides a battery comprising the above-mentioned lithium-rich manganese-based cathode material, thereby the battery having excellent specific capacity, rate performance and cycle performance.

[0007] In a first aspect, the present invention provides a lithium-rich manganese-based cathode material, comprising a lithium-rich manganese-based cathode material matrix, wherein the chemical formula of the lithium-rich manganese-based cathode material matrix includes: x(Li₂MnO₃)·y(LiNi a Co b Mn c M d Q e A kO2), where 0 < x < 1, 0 < y < 1, x + y = 1, 0.05 ≤ a ≤ 0.7, 0 < b ≤ 0.6, 0.01 ≤ c ≤ 0.8, 0 < d ≤ 0.1, 0 < e ≤ 0.1, 0 ≤ k ≤ 0.05, A includes at least one of La, Ce, Sm, and Y; M has an ionic radius ≥ 135 pm and an ionic electronegativity of 0.79~0.9; Q has an ionic radius of 54~80 pm and an ionic electronegativity of 1.3~2.1.

[0008] In the lithium-rich manganese-based cathode material described above, M includes Ba 2+ K + 、Rb + Cs + At least one of them;

[0009] And / or, the Q includes Ti 4+ Sb 3+ Mg 2+ Zn 2+ At least one of them;

[0010] And / or, in the X-ray diffraction pattern, the 2θ angle of the diffraction peak corresponding to the (003) crystal plane of the lithium-rich manganese-based cathode material is 18.2~19.2°;

[0011] And / or, the full width at half maximum (FWHM) of the diffraction peak corresponding to the (003) crystal plane of the lithium-rich manganese-based cathode material is 0.1~0.18°;

[0012] And / or, the full width at half maximum (FWHM) of the diffraction peak corresponding to the (104) crystal plane of the lithium-rich manganese-based cathode material is 0.2~0.26°;

[0013] And / or, the interlayer spacing d(003) of the (003) crystal plane of the lithium-rich manganese-based cathode material is 0.47~0.495 nm;

[0014] And / or, the interlayer spacing d(104) of the (104) crystal plane of the lithium-rich manganese-based cathode material is 0.19~0.215 nm;

[0015] And / or, the intensity ratio of the diffraction peak corresponding to the (003) crystal plane to the diffraction peak corresponding to the (104) crystal plane of the lithium-rich manganese-based cathode material is 1.5≤I(003) / I(104)≤2.

[0016] In the lithium-rich manganese-based cathode material described above, M occupies a transition metal site;

[0017] And / or, the Q occupies the Li site and / or the O site.

[0018] The lithium-rich manganese-based cathode material described above further includes a first coating layer covering at least a portion of the surface of the lithium-rich manganese-based cathode material matrix.

[0019] Preferably, the first coating layer comprises a lithium-containing compound;

[0020] Preferably, the first coating layer comprises Li2SiO3, Li2WO4, Li3PO4, Li2B2O4, or Li4Ti5O. 12 At least one of LiAlO2;

[0021] The first coating layer contains a monoclinic crystal structure and has a space group structure of P21 / c or P21 / n.

[0022] The lithium-rich manganese-based cathode material described above further includes a second coating layer covering at least a portion of the surface of the first coating layer;

[0023] Preferably, the second coating layer comprises a fast ion conductor.

[0024] The lithium-rich manganese-based cathode material described above, wherein the second coating layer comprises LiAlTi(PO4)3 and Li7La3Zr2O 12 Li 1.3 Al 0.1 Sc 0.2 Ti 1.7 (PO4)3, Li3Zr2Si2PO 12 At least one of them;

[0025] And / or, the coverage of the first coating layer is ≥90%;

[0026] And / or, the coverage of the second coating layer is 3~30%;

[0027] And / or, the thickness of the first coating layer is 1~5nm;

[0028] And / or, the thickness of the second coating layer is 0.01~1nm.

[0029] In the lithium-rich manganese-based cathode material described above, the mass content of M in the lithium-rich manganese-based cathode material is 2000~10000 ppm;

[0030] And / or, the Q content of the lithium-rich manganese-based cathode material is 2000~15000 ppm by mass;

[0031] Preferably, the absolute value of the difference between the mass content of Q and M is 0~5000ppm.

[0032] The lithium-rich manganese-based cathode material described above includes primary particles with a diameter of 0.1~0.5μm.

[0033] And / or, the lithium-rich manganese-based cathode material is a quasi-single-crystal material;

[0034] And / or, the pH value of the lithium-rich manganese-based cathode material is <11, and the residual alkali content is ≤1000ppm;

[0035] And / or, the Dv10 of the lithium-rich manganese-based cathode material is 0.5~2.2μm, the Dv50 is 1~5μm, and the Dv90 is 5~7μm;

[0036] And / or, the Span value of the lithium-rich manganese-based cathode material is 0.5~2, preferably 0.8~1.5;

[0037] And / or, the conductivity of the lithium-rich manganese-based cathode material is 1×10⁻⁶. -8 ~1×10 -2 S / cm;

[0038] And / or, the resistivity of the lithium-rich manganese-based cathode material is 1×10⁻⁶. 2 ~1×10 6 Ω·cm;

[0039] And / or, the specific surface area of ​​the lithium-rich manganese-based cathode material is 1~4m². 2 / g.

[0040] In a second aspect, the present invention provides a battery comprising the lithium-rich manganese-based cathode material as described above.

[0041] The battery described above includes an all-solid-state battery; the all-solid-state battery includes an electrolyte and a negative electrode;

[0042] The electrolyte includes at least one of polymer solid electrolyte, oxide solid electrolyte, sulfide solid electrolyte, and halide solid electrolyte.

[0043] And / or, the negative electrode includes at least one of carbon-based negative electrode, silicon-based negative electrode, titanium-based negative electrode, and lithium metal negative electrode.

[0044] The lithium-rich manganese-based cathode material provided by this invention utilizes the M element to form a low charge density barrier in the crystal lattice, suppressing oxygen release and lattice distortion; the Q element enhances oxygen coordination stability through strong bonding anchors, improving lattice order and crystallinity. The synergistic effect of these two elements significantly suppresses oxygen release, reduces structural phase transitions, and significantly slows down the structural degradation rate of the lithium-rich manganese-based cathode material during cycling, reducing irreversible capacity loss. Simultaneously, it suppresses interfacial side reactions, thereby extending battery cycle life and increasing specific capacity. Furthermore, this dual-doped system significantly improves ionic and electronic conductivity. Under high-rate charge / discharge scenarios, lithium ions can be rapidly inserted or extracted, and electrons can be efficiently transferred, avoiding polarization caused by charge accumulation, thus improving the battery's rate performance. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the accompanying drawings used in the description of the embodiments of the present invention or related technologies are briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 SEM image of the lithium-rich manganese-based cathode material of Example 1 provided by the present invention, magnified at 100,000 times;

[0047] Figure 2 SEM image of the lithium-rich manganese-based cathode material of Example 1 provided by the present invention, magnified at 10000x.

[0048] Figure 3 A schematic diagram of the structure of a lithium-rich manganese-based cathode material provided by the present invention;

[0049] Figure 4 XRD patterns of lithium-rich manganese-based cathode materials provided in Examples 1-3 and Comparative Example 1 of this invention;

[0050] Figure 5 A cross-sectional SEM image of the lithium-rich manganese-based cathode material provided in Example 1 of this invention;

[0051] Figure 6 EDS diagram of Ni element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention;

[0052] Figure 7 EDS diagram of Co element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention;

[0053] Figure 8 EDS diagram of Mn element in lithium-rich manganese-based cathode material of Example 1 provided by the present invention;

[0054] Figure 9 EDS diagram of O element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention;

[0055] Figure 10 EDS diagram of Ba element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention;

[0056] Figure 11 EDS diagram of Ti element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention;

[0057] Figure 12 SEM image of the lithium-rich manganese-based cathode material of Comparative Example 1 provided by the present invention;

[0058] Figure 13 SEM image of the lithium-rich manganese-based cathode material of Example 2 provided by the present invention;

[0059] Figure 14 SEM image of the lithium-rich manganese-based cathode material of Example 3 provided by the present invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0061] Lithium-rich manganese-based cathode materials have become core candidate materials for next-generation high-energy-density lithium-ion batteries due to their outstanding advantages such as high theoretical energy density, relatively low cost, and environmental friendliness. Based on a synergistic redox reaction mechanism between anions and cations, they can achieve a discharge specific capacity far exceeding that of traditional layered materials, possessing enormous potential to break through the energy density bottleneck of existing batteries. However, this material faces several key challenges in practical applications: low initial coulombic efficiency; irreversible structural phase transitions and oxygen loss at high operating voltages, leading to rapid reversible capacity decay during cycling; low electronic conductivity and lithium-ion diffusion coefficient, resulting in poor rate performance and difficulty in meeting the demands of rapid charge and discharge; and voltage decay issues also restrict the full realization of its energy density.

[0062] To address the aforementioned issues, existing technologies primarily employ modification methods such as element doping and surface coating for optimization. However, these methods fail to fundamentally and synergistically improve the structural stability, electron transport efficiency, and ion diffusion capabilities of the materials. Consequently, the specific capacity, rate performance, and cycle performance of the modified batteries still fall short of the comprehensive requirements for commercial applications, thus limiting the large-scale promotion of lithium-rich manganese-based cathode materials.

[0063] The inventors of this application have discovered through research that by defining the chemical formula of the lithium-rich manganese-based cathode material matrix and doping it with two elements of specific ionic radius and ionic electronegativity, the specific capacity, rate performance, and cycle performance of the battery can be significantly improved.

[0064] Based on this, in a first aspect, the present invention provides a lithium-rich manganese-based cathode material, comprising a lithium-rich manganese-based cathode material matrix, wherein the chemical formula of the lithium-rich manganese-based cathode material matrix includes: x(Li₂MnO₃)·y(LiNi a Co b Mn c M d Q e A k O2), wherein 0 < x < 1, 0 < y < 1, x + y = 1, 0.05 ≤ a ≤ 0.7, 0 < b ≤ 0.6, 0.01 ≤ c ≤ 0.8, 0 < d ≤ 0.1, 0 < e ≤ 0.1, 0 ≤ k ≤ 0.05, A includes at least one of La, Ce, Sm, and Y; M has an ionic radius ≥ 135 pm, for example, it can be a range of 135 pm, 136 pm, 137 pm, 138 pm, 139 pm, 140 pm, 145 pm, 150 pm, 160 pm, 170 pm or any two of them; the ionic electronegativity is 0.79~0.9, for example, it can be a range of 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9 or any two of them. The ionic radius of Q is 54 to 80 pm, for example, it can be a range of 54 pm, 55 pm, 56 pm, 60 pm, 62 pm, 65 pm, 70 pm, 75 pm, 80 pm or any two of these; the ionic electronegativity is 1.3 to 2.1, for example, it can be a range of 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1 or any two of these.

[0065] For example, x can be a range consisting of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.99, or any two of them, preferably 0.3 < x < 0.7; y can be a range consisting of 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.99, or any two of them, preferably 0.3 < y < 0.7; a can be a range consisting of 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or any two of them; b can be 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, or any two of them. The range can be any two of the following: c can be any two of 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8; d can be any two of 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1; e can be any two of 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1; k can be any two of 0, 0.01, 0.02, 0.03, 0.04, 0.05.

[0066] It should be noted that when M includes multiple elements, each element must satisfy the following conditions: ionic radius ≥ 135 pm, ionic electronegativity 0.79~0.9; similarly, when Q includes multiple elements, each element must satisfy the following conditions: ionic radius 54~80 pm, ionic electronegativity 1.3~2.1.

[0067] This invention defines the chemical formula of a lithium-rich manganese-based cathode material matrix, which includes two elements with specific ionic radii and electronegativity. When applied to batteries, this material improves the battery's specific capacity, rate performance, and cycle performance. This is because the M element forms MO bonds in the crystal lattice, promoting c-axis expansion, significantly enhancing lithium-ion diffusion kinetics, forming a low charge density barrier, and suppressing oxygen release and lattice distortion. The Q element enhances oxygen coordination stability through strong bonding anchors, helping to stabilize the oxygen coordination environment and improve lattice order and crystallinity. The synergistic effect of these two elements significantly suppresses oxygen release, reduces structural phase transitions, significantly slows down the structural degradation rate of the lithium-rich manganese-based cathode material during cycling, reduces irreversible capacity loss, and suppresses interfacial side reactions, thereby extending battery cycle life and improving specific capacity. In addition, this dual-doped system significantly improves ionic and electronic conductivity. In high-rate charge and discharge scenarios, lithium ions can be quickly inserted or extracted, and electrons can be efficiently transferred, avoiding polarization caused by charge accumulation, thereby improving the rate performance of the battery.

[0068] Therefore, the lithium-rich manganese-based cathode material provided by the present invention can improve the specific capacity, rate performance and cycle performance of the battery by defining the chemical formula of the lithium-rich manganese-based cathode material matrix and doping it with two elements with specific ionic radii and ionic electronegativity.

[0069] In some embodiments of the present invention, M includes Ba. 2+ K + 、Rb + Cs + At least one of them.

[0070] In some embodiments, Q includes Ti 4+ Sb 3+ Mg 2+ Zn 2+ At least one of them.

[0071] When the types of M elements are within the above range, oxygen release and lattice distortion can be further suppressed. When the types of Q elements are within the above range, lattice order and crystallinity can be further improved. The synergy of the two can significantly suppress oxygen release, reduce structural phase transitions, suppress interfacial side reactions, and improve ionic and electronic conductivity, thereby further improving the specific capacity, rate performance and cycle performance of the battery.

[0072] In the X-ray diffraction pattern, the 2θ angle of the diffraction peak corresponding to the (003) crystal plane of the lithium-rich manganese-based cathode material is 18.2~19.2°, for example, it can be a range of 18.2°, 18.3°, 18.4°, 18.5°, 18.6°, 18.7°, 18.8°, 18.9°, 19.0°, 19.1°, 19.2° or any combination thereof.

[0073] The leftward shift of the 2θ angle of the diffraction peak corresponding to the (003) crystal plane of the aforementioned lithium-rich manganese-based cathode material indicates lattice c-axis expansion. In the layered structure of the lithium-rich manganese-based cathode material, the c-axis is perpendicular to the lithium layer, and the expansion of the c-axis directly corresponds to an increase in the interplanar spacing d(003). According to Bragg's equation, the leftward shift of the 2θ angle means an increase in d(003), resulting in more abundant interlayer porosity.

[0074] A wider interlayer spacing reduces the resistance to lithium-ion migration between layers, increasing the lithium-ion diffusion coefficient and significantly improving the material's high-rate charge-discharge performance, meeting the fast-charging requirements of batteries or electronic devices. Furthermore, ample interlayer space can accommodate more lithium-ions participating in the insertion / extraction reaction, reducing capacity loss caused by hindered lithium insertion and ensuring the material exhibits its high specific capacity advantage through synergistic redox reactions of anions and cations. Additionally, moderate expansion of the c-axis enhances the lattice's elastic buffering capacity, offsetting the volume change stress caused by lithium-ion insertion / extraction and preventing crystal slippage and structural collapse.

[0075] In some embodiments, the full width at half maximum (FWHM) of the diffraction peak corresponding to the (003) crystal plane of the lithium-rich manganese-based cathode material is 0.1 to 0.18°, for example, it can be a range of 0.1°, 0.11°, 0.12°, 0.13°, 0.14°, 0.15°, 0.16°, 0.17°, 0.18° or any combination thereof.

[0076] In some embodiments, the half-width at half-maximum (WHM) of the diffraction peak corresponding to the (104) crystal plane of the lithium-rich manganese-based cathode material is 0.2 to 0.26°, for example, it can be a range of 0.2°, 0.21°, 0.22°, 0.23°, 0.24°, 0.25°, 0.26° or any two of them.

[0077] The full width at half maximum (FWHM) of a diffraction peak is negatively correlated with the crystal grain size and positively correlated with the degree of lattice defects. The narrower the FWHM, the larger the material grain size, the fewer the lattice defects, and the higher the crystallinity.

[0078] (003) The half-width of the diffraction peaks corresponding to the crystal plane is within the above range, indicating that the lithium layer and transition metal layer of the corresponding layered structure are arranged in a highly regular manner, with no obvious cation mixing or lattice distortion, providing a smooth and stable channel for lithium ion insertion and extraction. (104) The crystal plane is a characteristic crystal plane of the layered rock salt structure, and its narrow half-width further verifies the layered order of the material, while reflecting the uniform occupancy of transition metal ions in the lattice, avoiding capacity decay caused by local atomic disorder.

[0079] In some embodiments, the interlayer spacing d(003) of the (003) crystal plane of the lithium-rich manganese-based cathode material is 0.47~0.495 nm, for example, it can be a range of 0.47 nm, 0.475 nm, 0.48 nm, 0.485 nm, 0.49 nm, 0.495 nm or any combination thereof.

[0080] In some embodiments, the interlayer spacing d(104) of the (104) crystal plane of the lithium-rich manganese-based cathode material is 0.19~0.215 nm, for example, it can be a range of 0.19 nm, 0.195 nm, 0.20 nm, 0.205 nm, 0.21 nm, 0.215 nm or any two of them.

[0081] The range of the interlayer spacing d(003) of the (003) crystal plane can enable rapid insertion and extraction of lithium ions and also avoid crystal plane slippage during cycling caused by weak interlayer forces.

[0082] (104) The interlayer spacing d(104) of the crystal plane corresponds to the degree of dense packing of the transition metal layer. Together with d(003), it maintains the overall stability of the layered structure, avoids the influence of the lithium layer on the integrity due to the distortion of the transition metal layer, and further ensures the structural reversibility during cycling.

[0083] In some embodiments, the intensity ratio of the diffraction peak corresponding to the (003) crystal plane and the diffraction peak corresponding to the (104) crystal plane of the lithium-rich manganese-based cathode material is 1.5≤I(003) / I(104)≤2, for example, it can be a range of 1.5, 1.6, 1.7, 1.8, 1.9, 2 or any two of them.

[0084] I(003) / I(104) is the core indicator for evaluating the degree of cation mixing in lithium-rich manganese-based cathode materials. The higher the ratio, the higher the separation between the lithium layer and the transition metal layer, and the less cation mixing.

[0085] The range of I(003) / I(104) indicates that the material has no serious cation mixing, the layered structure of the material is more ordered, the material has better crystallinity, high grain integrity, and reduced lattice strain.

[0086] In some embodiments of the present invention, M occupies a transition metal site.

[0087] In some embodiments, Q occupies Li sites and / or O sites.

[0088] M occupies transition metal sites, constructing a "low charge density barrier" to inhibit oxygen release and structural collapse; Q occupies Li sites and / or O sites, constructing strong bonding anchors, stabilizing the oxygen coordination environment, and improving ion transport and interface stability; the two work together to achieve a triple breakthrough in structural stability, interface optimization, and improved electrochemical reversibility.

[0089] In some embodiments of the present invention, the lithium-rich manganese-based cathode material further includes a first coating layer covering at least a portion of the surface of the lithium-rich manganese-based cathode material matrix.

[0090] Preferably, the first coating layer comprises a lithium-containing compound.

[0091] Preferably, the first coating layer comprises Li2SiO3, Li2WO4, Li3PO4, Li2B2O4, or Li4Ti5O. 12 At least one of LiAlO2.

[0092] The first cladding layer contains a monoclinic crystal structure with a space group structure of P21 / c or P21 / n.

[0093] The first coating layer is preferably Li2WO4, which has a monoclinic crystal structure and a space group P21 / c structure.

[0094] The first coating layer can remove residual alkali on the surface and form ion-electron channels, thereby improving the interfacial ion transport rate and material surface stability, and enhancing cycle stability.

[0095] Lithium-containing compounds with P21 / c or P21 / n monoclinic crystal structures exhibit high lattice parameter matching with the lithium-rich manganese-based substrate structure (C2 / m space group). The low degree of lattice distortion at the interface allows for the formation of a stable coating interface, preventing coating layer cracking and detachment due to lattice mismatch. Furthermore, the regular molecular arrangement of monoclinic lithium-containing compounds results in a denser coating layer than amorphous coating layers, effectively preventing direct contact between the electrolyte and the lithium-rich manganese-based cathode material matrix. This inhibits the erosion of the lithium-rich manganese-based cathode material matrix by corrosive substances such as HF in the electrolyte and reduces the erosion caused by transition metal ions (such as Mn). 2+ It can prevent the dissolution and loss of lithium-rich manganese-based cathode materials, and at the same time prevent the formation of irreversible rock salt phase on the surface of the lithium-rich manganese-based cathode material matrix, thereby improving the cycle performance of the battery.

[0096] In some embodiments of the present invention, the lithium-rich manganese-based cathode material further includes a second coating layer covering at least a portion of the surface of the first coating layer. A schematic diagram of the structure of the lithium-rich manganese-based cathode material is shown below. Figure 3 As shown.

[0097] Preferably, the second coating layer comprises a fast ion conductor.

[0098] Fast ion conductors can enhance the interfacial contact between materials and solid electrolytes, reduce interfacial impedance and improve lithium-ion transport efficiency, which helps to improve the rate performance and cycle stability of batteries.

[0099] In some embodiments of the present invention, the second coating layer includes LiAlTi(PO4)3 and Li7La3Zr2O.12 Li 1.3 Al 0.1 Sc 0.2 Ti 1.7 (PO4)3, Li3Zr2Si2PO 12 At least one of the following. This can further reduce interface impedance and improve lithium-ion transport efficiency, thereby enhancing the rate performance and cycle stability of the battery.

[0100] In some embodiments, the coverage of the first covering layer is ≥90%, for example, it can be a range of 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, or any two of these.

[0101] The coverage of the first coating layer allows the surface of the lithium-rich manganese-based cathode material substrate to be effectively covered by the lithium compound coating layer, i.e., it is a film-like coating with no obvious exposed areas. This effectively blocks the direct contact between the lithium-rich manganese-based cathode material substrate and the electrolyte, inhibits the dissolution of transition metal ions, loss of lattice oxygen, and irreversible structural phase transitions, thereby improving the cycle performance of the battery.

[0102] In some embodiments, the coverage of the second covering layer is 3 to 30%, for example, it can be a range of 3%, 5%, 10%, 15%, 20%, 25%, 30%, or any two of these.

[0103] The second coating layer has a lower coverage, i.e., it is island-shaped. On the one hand, a small number of fast ion conductors can form discrete high-speed ion channels on the surface of the first coating layer to meet the requirements of rapid lithium-ion transport. On the other hand, it avoids the coating layer being too thick due to full coverage, reduces the interface impedance, and at the same time reserves enough surface space of the first coating layer to prevent mutual interference between different coating components.

[0104] In some embodiments, the thickness of the first coating layer is 1 to 5 nm, for example, it can be a range of 1 nm, 2 nm, 3 nm, 4 nm, 5 nm or any two of them.

[0105] The thickness of the first coating layer is within the above range, which can form a dense protective barrier and prevent the ion transport path from being prolonged due to excessive thickness of the first coating layer. This ensures the rapid migration of lithium ions between the lithium-rich manganese-based cathode material matrix and the first coating layer, while avoiding excessive lattice mismatch stress between the first coating layer and the lithium-rich manganese-based cathode material matrix.

[0106] In some embodiments, the thickness of the second coating layer is 0.01~1nm, for example, it can be a range of 0.01nm, 0.05nm, 0.1nm, 0.2nm, 0.3nm, 0.4nm, 0.5nm, 0.6nm, 0.7nm, 0.8nm, 0.9nm, 1nm or any two of these.

[0107] The thickness of the second coating layer is within the above range, which allows the fast ion conductor to form continuous conductive sites, reduces the interfacial charge transfer impedance, and does not hinder the wettability of the electrolyte and the coating layer, thus ensuring the rapid migration of lithium ions.

[0108] In some embodiments of the present invention, the mass content of M in the lithium-rich manganese-based cathode material is 2000~10000ppm, for example, it can be a range of 2000ppm, 3000ppm, 4000ppm, 5000ppm, 6000ppm, 7000ppm, 8000ppm, 9000ppm, 10000ppm or any two of these.

[0109] The amount of M ensures sufficient M ions to enter the transition metal layer, enhancing the bonding energy of the transition metal-oxygen bond and suppressing the layered phase transition and Mn under high voltage cycling. 3+ Disproportionation dissolution provides the basic structural stability of the material and can also prevent lattice distortion caused by excessive M ions, thereby improving the specific capacity and cycle performance of the battery.

[0110] In some embodiments, Q accounts for 2000~15000 ppm of the mass content of the lithium-rich manganese-based cathode material, for example, it can be a range of 2000 ppm, 3000 ppm, 4000 ppm, 5000 ppm, 6000 ppm, 7000 ppm, 8000 ppm, 9000 ppm, 10000 ppm, 11000 ppm, 12000 ppm, 13000 ppm, 14000 ppm, 15000 ppm or any two of these.

[0111] The Q content can moderately widen the lithium interlayer spacing and reduce lithium-ion migration resistance; at the same time, it stabilizes the lattice charge balance through charge compensation, reducing structural stress during delithiation, thereby improving the battery's specific capacity, cycle performance, and rate performance. Furthermore, the Q content can enhance the stability of the oxygen coordination environment through strong electronegativity, suppressing lattice oxygen loss, thus improving the battery's specific capacity and cycle performance.

[0112] Preferably, the absolute value of the difference between the mass contents of Q and M is 0~5000ppm, for example, it can be a range of 0ppm, 100ppm, 500ppm, 1000ppm, 2000ppm, 3000ppm, 4000ppm, 5000ppm or any combination thereof. This can further reduce lithium-ion migration resistance, reduce structural stress during delithiation, and suppress lattice oxygen loss, thereby further improving the battery's specific capacity, cycle performance and rate performance.

[0113] In some embodiments of the present invention, the lithium-rich manganese-based cathode material includes primary particles with a diameter of 0.1~0.5 μm, for example, a range of 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, or any combination thereof. This can shorten the diffusion path of lithium ions within the particles, improve ion transport efficiency, and enhance rate performance.

[0114] In some embodiments, the lithium-rich manganese-based cathode material is a quasi-single-crystal material.

[0115] It is understandable that near-single-crystal cathode materials refer to cathode materials in which primary particles form a near-single-crystal structure within secondary particles through oriented growth or fusion. Its core characteristic is that the secondary particles consist of a few or a single large primary particle. The crystal structure has large single grains or ordered grains, but with a small number of grain boundaries.

[0116] The near-monocrystalline structure of lithium-rich manganese-based cathode materials can avoid the particle cracking and pulverization problems caused by grain boundary stress concentration in traditional polycrystalline materials during charge-discharge cycles, thus significantly improving the cycle life of batteries.

[0117] In some embodiments, the pH value of the lithium-rich manganese-based cathode material is <11, for example, it can be a range consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10.9 or any two of them; the residual alkali content is ≤1000ppm, for example, it can be a range consisting of 0ppm, 10ppm, 50ppm, 100ppm, 200ppm, 300ppm, 500ppm, 700ppm, 1000ppm or any two of them.

[0118] The residual alkali content can effectively reduce the acid-base side reactions between the electrolyte and the positive electrode surface, avoid the formation of high-resistivity interface products (such as Li2CO3 and LiF), and reduce interface impedance; at the same time, it can suppress the risk of battery gas swelling and improve the safety and cycle stability of the battery.

[0119] The pH value of lithium-rich manganese-based cathode materials is directly related to the residual alkali content. A pH value <11 can ensure the compatibility of lithium-rich manganese-based cathode materials with electrolytes and maintain long-term stability of interfacial impedance.

[0120] In some embodiments, the Dv10 of the lithium-rich manganese-based cathode material is 0.5~2.2μm, for example, it can be a range of 0.5μm, 0.7μm, 1μm, 1.5μm, 1.8μm, 2μm, 2.2μm or any two of these; the Dv50 is 1~5μm, for example, it can be a range of 1μm, 2μm, 3μm, 4μm, 5μm or any two of these; the Dv90 is 5~7μm, for example, it can be a range of 5μm, 5.2μm, 5.7μm, 6.3μm, 6.5μm, 7μm or any two of these.

[0121] Dv10 represents the particle size of the positive electrode active material when the cumulative volume reaches 10% from the smallest particle size side in the volume-based particle size distribution; Dv50 represents the particle size of the positive electrode active material when the cumulative volume reaches 50% from the smallest particle size side in the volume-based particle size distribution; Dv90 represents the particle size of the positive electrode active material when the cumulative volume reaches 90% from the smallest particle size side in the volume-based particle size distribution.

[0122] Within the Dv50 range, the compaction density of the positive electrode sheet can be increased, thereby improving the energy density of the battery. The Dv10 and Dv90 ranges can avoid excessive specific surface area caused by too many small particles, or polarization unevenness caused by too many large particles.

[0123] In some embodiments, the Span value of the lithium-rich manganese-based cathode material is 0.5 to 2, for example, it can be a range of 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2 or any two of these; preferably it is 0.8 to 1.5.

[0124] It is understandable that Span = (Dv90 - Dv10) / Dv50, which characterizes the uniformity of particle size distribution. The smaller the Span value, the narrower the particle size distribution. A Span value of 0.5 to 2 ensures that the electrochemical behavior of each particle within the electrode is consistent, avoiding capacity decay caused by local polarization differences. The preferred range of 0.8 to 1.5 balances uniformity and processing feasibility, and can improve the rate performance and cycle stability of the battery.

[0125] In some embodiments, the conductivity of the lithium-rich manganese-based cathode material is 1×10⁻⁶. -8 ~1×10 -2 S / cm, for example, can be 1×10 -8 S / cm, 1×10 -7 S / cm, 1×10 -6 S / cm, 1×10 -5 S / cm, 1×10 -4 S / cm, 1×10 -3 S / cm, 1×10 -2 A range consisting of S / cm or any two thereof can significantly reduce the charge transfer impedance of the electrodes and improve the high-rate charge-discharge performance of the battery.

[0126] In some embodiments, the resistivity of the lithium-rich manganese-based cathode material is 1×10⁻⁶. 2 ~1×10 6 Ω·cm, for example, can be 1×10 2 Ω·cm, 5×10 2 Ω·cm, 1×10 3 Ω·cm, 5×10 3 Ω·cm, 1×10 4 Ω·cm, 5×10 4 Ω·cm, 1×10 5 Ω·cm, 1×10 6 The range is defined as Ω·cm or any combination thereof. This avoids the destruction of the layered structure of lithium-rich manganese-based cathode materials due to excessive modification (such as high-concentration conductive phase doping), thus ensuring the high specific capacity advantage.

[0127] In some embodiments, the specific surface area of ​​the lithium-rich manganese-based cathode material is 1~4 m². 2 / g, for example, can be 1m 2 / g, 1.5m 2 / g、2m 2 / g, 2.5m 2 / g、3m 2 / g, 3.5m 2 / g、4m 2 / g or a range consisting of any two of them.

[0128] The specific surface area of ​​the aforementioned lithium-rich manganese-based cathode material can ensure sufficient contact between the lithium-rich manganese-based cathode material and the electrolyte, providing enough reaction sites for lithium-ion insertion and extraction; it can also avoid the increase of interfacial side reactions and accelerated electrolyte consumption caused by excessive specific surface area, thus maintaining the cycle life of the battery.

[0129] The preparation method of the lithium-rich manganese-based cathode material of the present invention includes the following steps:

[0130] A mixed solution containing transition metal salts, M source, and Q source was subjected to a co-precipitation reaction with an alkaline solution to obtain a lithium-rich manganese-based cathode material precursor.

[0131] A first system, including a lithium-rich manganese-based cathode material precursor and a lithium source, is subjected to a sintering process to obtain a lithium-rich manganese-based cathode material.

[0132] Specifically, a salt solution including transition metal salts, M source, and Q source can be mixed with an alkaline solution to obtain a mixed solution for later use. A certain amount of deionized water is added to a reactor, and a peristaltic pump is used to pump the mixed solution into the reactor at a specific feed rate. The stirring speed and the temperature of the circulating water are controlled, and the alkaline feed rate is adjusted using a three-stage speed control to maintain the pH of the solution system at 6-9. The feeding time is 20-40 hours. After the reaction is complete, the slurry is subjected to solid-liquid separation, centrifuged and washed with deionized water, and dried to obtain a lithium-rich manganese-based cathode material precursor doped with M and Q.

[0133] The above-mentioned lithium-rich manganese-based cathode material precursor is mixed with a lithium source to obtain a first system. The uniformly mixed first system is placed in a muffle furnace for a sintering process. After sintering, the material is taken out and ground to obtain the lithium-rich manganese-based cathode material.

[0134] The total concentration of metal ions in the salt solution can be 1-4 mol / L, and the alkaline solution can be a mixed alkaline solution of NaOH and NH3•H2O, with a molar concentration of NaOH of 1-5 mol / L and a molar concentration of NH3•H2O of 0.1-0.5 mol / L. The feed rate of the mixed solution can be 100-200 ml / h, the stirring speed can be 500-2000 rpm, the temperature of the circulating water can be 45-70℃, the drying temperature can be 100-200℃, and the time can be 18-30 h.

[0135] In some embodiments, the molar ratio of lithium in the lithium source to the sum of transition metal elements, M elements and Q elements in the lithium-rich manganese-based cathode material precursor is (1.4~1.8):1.

[0136] By adding M-sources and Q-sources during the preparation of lithium-rich manganese-based cathode material precursors and employing a simple and easily implemented co-precipitation method, lithium-rich manganese-based cathode material precursors doped with both metals can be obtained, achieving large-scale production. The two doping elements improve the material's conductivity, enhance electrochemical performance, and reduce oxygen release.

[0137] In some embodiments of the present invention, the first sintering process includes: heating to 450-600°C at 1-3°C / min and holding for 4-8 hours, then heating to 750-900°C at 1-3°C / min and holding for 8-12 hours, and then heating to 950-1000°C at 1-3°C / min and holding for 4-6 hours.

[0138] The single sintering process is achieved by setting multiple heating platforms. The first heating platform is 450~600℃, which is the lithium source dissolution temperature. After dissolution, diffusion is facilitated, which helps to uniformly distribute the lithium-rich manganese-based cathode material precursor. The second heating platform is 750~900℃. This heating platform is the main stage for the formation of the material's layered structure and determines the size of the primary particles and the properties of lithium-nickel mixing. The third heating platform is 950~1000℃, which further stabilizes the layered structure of the material and makes the particle size more uniform.

[0139] In some embodiments, the preparation method further includes: performing a secondary sintering treatment on a second system comprising lithium-rich manganese-based cathode material and solid acid to obtain a lithium-rich manganese-based cathode material with a first coating layer.

[0140] Preferably, the secondary sintering treatment is carried out at a temperature of 500~700℃ for 8~12h, with a heating rate of 1~5℃ / min. The mass ratio of lithium-rich manganese-based cathode material to solid acid is 100:(0.5~2).

[0141] The first coating layer is a film-like coating of lithium-containing compounds formed by coating solid acid. The solid acid consumes the residual alkali on the surface of the lithium-rich manganese-based cathode material, generates lithium-containing compounds, removes the passivation layer on the surface of the lithium-rich manganese-based cathode material, and forms ion-electron channels, improving the ion-electron transport rate at the material interface.

[0142] In some embodiments, the preparation method further includes: performing three sintering treatments on a third system comprising a lithium-rich manganese-based cathode material having a first coating layer and a second coating material precursor to obtain a lithium-rich manganese-based cathode material having a first coating layer and a second coating layer.

[0143] Preferably, the temperature of the three sintering treatments is 800~1000℃, the time is 8~12h, and the heating rate is 1~5℃ / min. The mass ratio of the lithium-rich manganese-based cathode material with the first coating layer to the precursor of the second coating material is 100:(3~10).

[0144] The second coating layer is a fast ion conductor generated in situ through the second coating material precursor. The first and second coating layers work together to improve the surface structure of lithium-rich manganese-based cathode materials, increase conductivity, improve specific capacity, rate performance and cycle performance in batteries, and improve contact with solid electrolytes.

[0145] Secondly, the present invention provides a battery comprising the lithium-rich manganese-based cathode material as described above, thus the battery has excellent specific capacity, rate performance and cycle performance.

[0146] As one implementation method, the battery of the present invention can be prepared using conventional methods in the art. Specifically, the positive electrode, separator and negative electrode can be stacked in sequence, and the cell can be obtained by stacking or winding process. Then, the battery can be obtained by baking, liquid injection, formation and packaging.

[0147] The positive electrode sheet can be prepared using conventional techniques in the field. Specifically, the above-mentioned lithium-rich manganese-based positive electrode material, conductive agent, and binder can be uniformly dispersed in a solvent to obtain a positive electrode active slurry. Then, the positive electrode active slurry is coated on at least one functional surface of the positive electrode current collector, and after drying, the positive electrode sheet of the present invention can be obtained.

[0148] This invention does not specifically limit the categories of conductive agents and adhesives. The conductive agents, adhesives and other components can all be conventional substances in the art. For example, the conductive agent may include one or more of conductive carbon black, carbon nanotubes, conductive graphite and graphene, and the adhesive may include one or more of polyvinylidene fluoride (PVDF), acrylic modified PVDF, polyacrylate polymers, polyimide, styrene-butadiene rubber and styrene-acrylic rubber.

[0149] The present invention does not specifically limit the coating method, and any coating method such as gravure coating, extrusion coating, spraying, screen printing, etc. can be used to achieve the coating of the positive electrode active layer slurry.

[0150] In addition to the positive electrode, the battery of the present invention may also include a separator, a negative electrode, and an electrolyte. The composition of the negative electrode can refer to conventional negative electrode sheets in the art, and the separator can also be a separator commonly used in the art, such as a PP film or a PE film.

[0151] The battery of the present invention can be a single cell, a battery pack, a battery stack, or a cylindrical cell formed by connecting single cells. These cells can be electrically connected by conventional methods in the art, such as series connection, parallel connection, or a hybrid connection including these connection methods, etc., without particular limitation.

[0152] In some embodiments of the present invention, the battery includes an all-solid-state battery, which can further improve the contact effect between the lithium-rich manganese-based cathode material and the solid electrolyte, thereby further improving the specific capacity, cycle performance and rate performance of the all-solid-state battery.

[0153] The all-solid-state battery includes an electrolyte and a negative electrode; the electrolyte includes at least one of polymer solid electrolyte, oxide solid electrolyte, sulfide solid electrolyte, and halide solid electrolyte; in some embodiments, the negative electrode includes at least one of carbon-based negative electrode, silicon-based negative electrode, titanium-based negative electrode, and lithium metal negative electrode.

[0154] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0155] Example 1

[0156] The preparation method of the lithium-rich manganese-based cathode material in this embodiment includes the following steps:

[0157] 1) A mixed solution is obtained by mixing a salt solution containing NiSO4, CoSO4, MnSO4, BaSO4, and Ti(SO4)2 with a mixed alkaline solution containing NaOH and NH3•H2O. The total concentration of metal ions in the salt solution is 2 mol / L, and Ni... 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ The molar ratio of NaOH to NH3•H2O was 0.125:0.125:0.74:0.05:0.05, with a molar concentration of 3 mol / L and 0.2 mol / L. A certain amount of deionized water was added to the reactor, and the mixture was pumped into the reactor at a feed rate of 175 ml / h using a peristaltic pump. The stirring speed was controlled at 1000 rpm, the circulating water temperature at 55℃, and the alkaline feed rate was adjusted using a three-stage speed control to maintain the pH of the solution at 7.5. The feeding time was 30 h. After the reaction, the slurry was subjected to solid-liquid separation, centrifuged and washed with deionized water, and then dried at 120℃ for 24 h to obtain Ni, a lithium-rich manganese-based cathode material precursor doped with Ba and Ti. 0.125 Co 0.125 Mn 0.74 Ba 0.05 Ti 0.05 (OH)2.

[0158] 2) The above-mentioned lithium-rich manganese-based cathode material precursor and LiOH•H2O were mixed to obtain the first system, wherein n(Li):n(Me) = 1.61:1, and Me is the sum of Ni, Co, Mn, Ba, and Ti. The uniformly mixed first system was placed in a muffle furnace, and the temperature was first increased to 500℃ at 1℃ / min and held for 5 hours, then increased to 850℃ at 2℃ / min and held for 10 hours, and then increased to 1000℃ at 1℃ / min and held for 5 hours. After sintering, the material was taken out and ground to obtain the lithium-rich manganese-based cathode material matrix 0.62(Li2MnO3)·0.38(LiNi 0.329 Co 0.329 Mn 0.315 Ba 0.0135 Ti 0.0135 O2).

[0159] 3) Mix 100g of the above-mentioned lithium-rich manganese-based cathode material matrix with 1g of tungstic acid, and use a high-speed mixer to mix at 900r / min for 10min. After mixing evenly, put the mixture into a muffle furnace, heat it to 600℃ at 2℃ / min, and perform secondary sintering for 10h to obtain a lithium-rich manganese-based cathode material with a first coating layer.

[0160] 4) Mix 9.404g NH4H2PO4, 1.388g Al2O3, 0.1669g TiO2, and 1.142g LiOH·H2O (n(P):n(Al):n(Ti):n(Li)=3:1:1:1) to obtain the second coating material precursor, namely the LATP precursor.

[0161] 5) Mix 100g of the lithium-rich manganese-based cathode material with the first coating layer and 5g of LATP precursor evenly using a high-speed mixer. Place the mixture in a muffle furnace and heat it to 900℃ at 2℃ / min. Perform three sinterings for 10h to obtain the lithium-rich manganese-based cathode material with the first coating layer and the second coating layer.

[0162] The lithium-rich manganese-based cathode material includes a lithium-rich manganese-based cathode material matrix, a first coating layer covering at least a portion of the surface of the lithium-rich manganese-based cathode material matrix, and a second coating layer covering at least a portion of the surface of the first coating layer. The first coating layer includes Li₂WO₄, which has a monoclinic crystal structure and a P21 / c space group structure. The second coating layer includes LiAlTi(PO₄)₃, and the lithium-rich manganese-based cathode material is a near-single-crystal material. Ba occupies transition metal sites, and Ti occupies Li sites and O sites.

[0163] Example 2: Unlike Example 1, step 3 is omitted, that is, the first covering layer is not covered.

[0164] Example 3: Unlike Example 1, steps 4) and 5) are omitted, that is, the second covering layer is not covered.

[0165] Example 4: Unlike Example 1, steps 3) to 5) are omitted, that is, the first and second covering layers are not covered.

[0166] Example 5: The difference from Example 1 is that BaSO4 is replaced with K2SO4 in step 1).

[0167] Example 6: Unlike Example 1, BaSO4 in step 1) is replaced with Rb2SO4.

[0168] Example 7: The difference from Example 1 is that BaSO4 is replaced with Cs2SO4 in step 1).

[0169] Example 8: Unlike Example 1, Ti(SO4)2 in step 1) is replaced with MgSO4.

[0170] Example 9: Unlike Example 1, Ti(SO4)2 in step 1) is replaced with Sb2(SO4)3.

[0171] Example 10: Unlike Example 1, Ti(SO4)2 in step 1) is replaced with ZnSO4.

[0172] Example 11: Unlike Example 1, silicic acid is used in step 3).

[0173] Example 12: Unlike Example 1, boric acid is used in step 3).

[0174] Example 13: Unlike Example 1, titanic acid is used in step 3).

[0175] Example 14: Unlike Example 1, aluminic acid is used in step 3).

[0176] Example 15: Unlike Example 1, in step 4), 10.576g LiOH·H2O, 0.88g La2O3, and 0.68g ZrO2 (n(La):n(Zr):n(Li)=3:2:7) are mixed to obtain the second coating material precursor, namely the LLZO precursor.

[0177] Step 5) Mix 100g of the lithium-rich manganese-based cathode material with the first coating layer and 5g of LLZO precursor evenly using a high-speed mixer. Place the mixture in a muffle furnace and heat it to 900℃ at 2℃ / min. Perform three sinterings for 10h to obtain the lithium-rich manganese-based cathode material with the first coating layer and the second coating layer.

[0178] Example 16: The difference from Example 1 is that in step 4): 2.67g LiOH·H2O, 15.10g ZrO2, 8.01g SiO2, and 6.533g H3PO4 (n(P):n(Zr):n(Si):n(Li)=1:2:2:7) are mixed to obtain the second coating material precursor, namely LZSPO precursor.

[0179] Step 5) Mix 100g of the lithium-rich manganese-based cathode material with the first coating layer and 5g of LZSPO precursor evenly using a high-speed mixer. Place the mixture in a muffle furnace and heat it to 900℃ at 2℃ / min. Perform three sinterings for 10h to obtain the lithium-rich manganese-based cathode material with the first coating layer and the second coating layer.

[0180] Example 17: Unlike Example 1, the mass of LATP precursor used in step 5) is 0.5g.

[0181] Example 18: Unlike Example 1, the mass of LATP precursor used in step 5) is 10g.

[0182] Example 19: Unlike Example 1, the mass of tungstic acid used in step 3) is 0.2g.

[0183] Example 20: Unlike Example 1, the mass of tungstic acid used in step 3) is 6g.

[0184] Example 21: The difference from Example 1 is that Ni in step 1) 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ The molar ratio is 0.1265:0.1265:0.7422:0.00494:0.0114.

[0185] Example 22: The difference from Example 1 is that Ni in step 1) 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ The molar ratio is 0.1252:0.1252:0.7399:0.00483:0.00201.

[0186] Example 23: The difference from Example 1 is that Ni in step 1) 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ The molar ratio is 0.1224:0.1224:0.7344:0.00471:0.00859.

[0187] Example 24: The difference from Example 1 is that Ni in step 1) 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ The molar ratio is 0.1214:0.1214:0.7301:0.00464:0.00904.

[0188] Example 25: The difference from Example 1 is that Ni in step 1) 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+The molar ratio is 0.1265:0.1265:0.7416:0.000646:0.005928.

[0189] Example 26: The difference from Example 1 is that Ni in step 1) 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ The molar ratio is 0.1269:0.1269:0.7399:0.001292:0.00494.

[0190] Example 27: The difference from Example 1 is that Ni in step 1) 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ The molar ratio is 0.125552:0.125552:0.740223:0.003724:0.00494.

[0191] Example 28: The difference from Example 1 is that Ni in step 1) 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ The molar ratio is 0.120954:0.120954:0.736356:0.009196:0.00494.

[0192] Example 29: The difference from Example 1 is that Ni in step 1) 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ The molar ratio is 0.120384:0.120384:0.736052:0.009424:0.00494.

[0193] Example 30: Unlike Example 1, in step 2), the temperature is first increased to 500°C at 1°C / min and held for 5 hours, then increased to 850°C at 2°C / min and held for 10 hours, and then increased to 880°C at 1°C / min and held for 5 hours.

[0194] Example 31: Unlike Example 1, in step 2), the temperature is first increased to 500°C at 1°C / min and held for 5 hours, then increased to 850°C at 2°C / min and held for 10 hours, and then increased to 1100°C at 1°C / min and held for 5 hours.

[0195] Example 32: Unlike Example 1, in step 3), a high-speed mixer is used to mix the materials at 1200 r / min for 10 min.

[0196] Example 33: Unlike Example 1, in step 3), a high-speed mixer is used to mix the materials at 500 r / min for 10 min.

[0197] Example 34: Unlike Example 1, in step 3), a high-speed mixer is used to mix the materials at 950 r / min for 13 min.

[0198] Example 35: Unlike Example 1, in step 3), a high-speed mixer is used to mix the materials at 1000 r / min for 3 min.

[0199] Example 36: Unlike Example 1, in step 3), a high-speed mixer is used to mix the materials at 1050 r / min for 15 min.

[0200] Example 37: The difference from Example 1 is that the mass of tungstic acid used in step 3) is 6g, and the mass of LATP precursor used in step 5) is 10g.

[0201] Example 38: Unlike Example 1, in step 1), a salt solution comprising NiSO4, CoSO4, MnSO4, BaSO4, Ti(SO4)2, and La2(SO4)3 is mixed with a mixed alkaline solution of NaOH and NH3•H2O to obtain a mixed solution. The total concentration of metal ions in the salt solution is 2 mol / L, and Ni... 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ :La 3+ The molar ratio is 0.1239:0.1239:0.7414:0.00506:0.00506:0.000689.

[0202] Example 39: Unlike Example 1, in step 1), a salt solution comprising NiSO4, CoSO4, MnSO4, BaSO4, Ti(SO4)2, and Ce2(SO4)3 is mixed with a mixed alkaline solution of NaOH and NH3•H2O to obtain a mixed solution. The total concentration of metal ions in the salt solution is 2 mol / L, and Ni... 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ :Ce 3+ The molar ratio is 0.1239:0.1239:0.7414:0.00506:0.00506:0.000689.

[0203] Example 40: Unlike Example 1, in step 1), a salt solution comprising NiSO4, CoSO4, MnSO4, BaSO4, Ti(SO4)2, and Sm2(SO4)3 is mixed with a mixed alkaline solution of NaOH and NH3•H2O to obtain a mixed solution. The total concentration of metal ions in the salt solution is 2 mol / L, and Ni... 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ :Sm 3+ The molar ratio is 0.1248:0.1248:0.7396:0.0051:0.0051:0.0006.

[0204] Example 41: Unlike Example 1, in step 1), a salt solution comprising NiSO4, CoSO4, MnSO4, BaSO4, Ti(SO4)2, and Y2(SO4)3 is mixed with a mixed alkaline solution of NaOH and NH3•H2O to obtain a mixed solution. The total concentration of metal ions in the salt solution is 2 mol / L, and Ni... 2+ :Co 2+ :Mn 2+ :Ba 2+ :Ti 4+ :Y 3+ The molar ratio is 0.1246:0.1246:0.7391:0.0051:0.0051:0.0009.

[0205] Comparative Example 1: Unlike Example 1, BaSO4 and Ti(SO4)2 were not added in step 1).

[0206] Comparative Example 2: Unlike Example 1, BaSO4 was not added in step 1).

[0207] Comparative Example 3: Unlike Example 1, Ti(SO4)2 was not added in step 1).

[0208] Comparative Example 4: Unlike Example 1, in step 1), BaSO4 was replaced with La2(SO4)3.

[0209] Comparative Example 5: Unlike Example 1, Ti(SO4)2 in step 1) is replaced with Ce2(SO4)3.

[0210] Comparative Example 6: Unlike Example 1, in step 1), BaSO4 was replaced with La2(SO4)3 and Ti(SO4)2 was replaced with Ce2(SO4)3.

[0211] Experimental example:

[0212] 1. Determination of the chemical formula of lithium-rich manganese-based cathode material matrix: The elemental composition, crystal diffraction pattern, bonding state and lattice vibration mode of the material were analyzed by X-ray diffraction (XRD) + Raman spectroscopy + inductively coupled plasma mass spectrometry (ICP-MS).

[0213] 2. Determination of the single-crystal structure of lithium-rich manganese-based cathode materials: The morphology and lattice structure of the materials were identified using scanning electron microscopy (SEM) and X-ray diffraction (XRD).

[0214] 3. Types and contents of M and Q: Inductively coupled plasma mass spectrometry (ICP-MS) was used to test the types and contents of M and Q. The ionic radius and electronegativity of the elements can be found from their types.

[0215] 4. Occupation sites: High-resolution transmission electron microscopy (HRTEM) + energy dispersive spectroscopy (EDS / EELS) is used to identify the coordination environment of M and Q with neighboring atoms.

[0216] 5. XRD: The XRD pattern of the lithium-rich manganese-based cathode material was obtained by X-ray diffraction. From the XRD pattern, the 2θ angle, half-maximum width, and peak intensity ratio of the diffraction peaks corresponding to the (003) and (104) crystal planes were determined.

[0217] Interlayer spacing: calculated according to Bragg's law d=2sinθλ.

[0218] 6. Determination of the materials for the first and second coating layers: determined through a combination of XRD and ICP test data.

[0219] 7. Coverage of the first and second coating layers: The coverage area ratio of the coating layers is calculated using scanning electron microscopy (SEM) + energy dispersive spectroscopy (EDS) combined with image analysis software (such as ImageJ) to obtain the coverage rate.

[0220] 8. Thickness of the first and second coating layers: obtained by TEM testing.

[0221] 9. Diameter of primary particles: Measured using nanomeasure software.

[0222] 10. pH value: At 25℃, 5g of lithium-rich manganese-based cathode material was placed in 45g of water, stirred and filtered to obtain a pH test solution of lithium-rich manganese-based cathode material. The pH value of the pH test solution of lithium-rich manganese-based cathode material was tested using a pH meter.

[0223] 11. Residual alkali content: At 25℃, 30g of lithium-rich manganese-based cathode material was placed in 100g of water, stirred thoroughly, and filtered to obtain a lithium-rich manganese-based cathode material solution. The solution was titrated with hydrochloric acid standard solution, and the residual alkali content of the lithium-rich manganese-based cathode material solution was calculated based on the results.

[0224] 12. Dv10, Dv50, Dv90, and Span values: The lithium-rich manganese-based cathode materials prepared in the examples and comparative examples were tested using a laser particle size analyzer. The Dv10, Dv50, and Dv90 values ​​were read, and SPAN = (Dv90 - Dv10) / Dv50. Dv50 represents the particle size of the cathode active material when the cumulative volume reaches 50% from the smallest particle size side in the volume-based particle size distribution; Dv10 represents the particle size of the cathode active material when the cumulative volume reaches 10% from the smallest particle size side in the volume-based particle size distribution; and Dv90 represents the particle size of the cathode active material when the cumulative volume reaches 90% from the smallest particle size side in the volume-based particle size distribution.

[0225] 13. Conductivity and resistivity: The test was conducted using a powder resistivity tester. 0.5g of lithium-rich manganese-based cathode material was weighed and added into the mold cavity through a weighing boat. After the powder was compacted, it was placed into the mold cavity and vibrated to make the sample flat and uniform. Then, the four-probe mold assembly punch was slowly placed on the mold cavity. The four-probe mold assembly was installed on the main unit and the BNC data cable was connected. The protection door was closed, the software was opened and the parameters were set. The pressure was set to 12Mpa. After the test started, the software automatically read the resistivity and conductivity values.

[0226] 14. Specific Surface Area: The specific surface area of ​​the lithium-rich manganese-based cathode materials prepared in the examples and comparative examples was tested. Specifically, the total weight of the empty small test tube and the stopper was weighed. The lithium-rich manganese-based cathode material powder sample to be tested was immersed in anhydrous ethanol for 4 hours. Then, the powder sample was taken out and dried in an oven at 105°C for half an hour. Next, the powder sample was placed in a sample tube, and the total weight of the powder sample, the small test tube, and the stopper was weighed to calculate the sample mass. The degassing station was turned on, and the small test tube containing the powder sample was placed in the degassing station at 105°C. Nitrogen (pure nitrogen) was purged for 30 minutes, cooled for 15 minutes, and then tested at 25°C and 60% humidity. P / P0, with points in the range of 0.05~0.25, was used as the x-axis, and P / V(P0-P) was used as the y-axis. A linear fit was performed by plotting the BET equation to obtain the slope and intercept of the straight line, thereby calculating the BET specific surface area of ​​the powder sample.

[0227] 15. Specific capacity of liquid battery: At 25°C and normal pressure, lithium-rich manganese-based positive electrode material, conductive carbon black, and binder polyvinylidene fluoride (PVDF) of each embodiment and comparative example were thoroughly mixed in N-methylpyrrolidone solvent at a mass ratio of 8:1:1 to obtain positive electrode slurry. The positive electrode slurry was coated on both sides of aluminum foil. After drying and rolling, positive electrode active material layers were formed on both sides of aluminum foil to obtain positive electrode sheet. Then, the positive electrode sheet was punched into small discs with a diameter of 12mm using a film die. After drying and weighing, it was assembled into CR2430 coin cell battery in a glove box under Ar protective atmosphere using CR2025 coin cell battery case, Li metal disc as negative electrode, and electrolyte (composed of 1.2mol / L LiPF6, solvent of DMC and FEC, volume ratio of DMC and FEC of 3:7).

[0228] A button cell battery is charged at a constant current rate of 0.1C to 4.6V at 25℃, and then charged at a constant voltage rate of 4.6V until the current is equal to 0.02mA. The charging capacity at this time is recorded as the first charge specific capacity. After resting for 10 minutes, it is discharged at a constant current rate of 0.1C to the voltage of 2V. The discharge capacity at this time is recorded as the battery's first discharge specific capacity.

[0229] 16. Rate performance of liquid batteries: The positive electrode material is coated with lithium-rich manganese-based material to form a positive electrode sheet according to the method in the coin cell capacity test. The negative electrode is made of graphite (graphite, conductive carbon black and styrene-butadiene rubber (SBR) are thoroughly mixed in deionized water at a mass ratio of 8:1:1 to obtain a negative electrode slurry. The negative electrode slurry is coated on both sides of copper foil. After drying and rolling, a negative electrode active material layer is formed on both sides of the copper foil to obtain a negative electrode sheet). The battery is composed of a polyethylene separator and an electrolyte (1.2 mol / L LiPF6, solvents are DMC and FEC, and the volume ratio of DMC and FEC is 3:7).

[0230] The full battery is charged at a constant current rate of 0.1C to a voltage of 4.6V at 25℃, then charged at a constant voltage rate of 4.6V to a current of 0.02mA. After resting for 10 minutes, it is discharged at a constant current rate of 0.1C to a voltage of 2V. The capacity at this point is recorded as the discharge capacity at the 0.1C rate. After resting for 10 minutes, it is charged at a constant current rate of 1C to a voltage of 4.6V, then charged at a constant voltage rate of 4.6V to a current of 0.02mA. After resting for 10 minutes, it is discharged at a constant current rate of 1C to a voltage of 2V. The capacity at this point is recorded as the discharge capacity at the 1C rate. The discharge capacity at the 1C rate divided by the discharge capacity at the 0.1C rate is the 1C rate performance.

[0231] 17. Cyclic performance of liquid batteries: The full battery was charged at 25°C with a constant current of 1C to 4.6V, then charged at 4.6V with a constant voltage until the current equals 0.02mA. It was then discharged at a 1C rate to 2V, and this charge-discharge cycle was repeated 100 times. The discharge capacity Q1 at the first cycle and the discharge capacity Q at the 100th cycle were measured. 100 The capacity retention rate after 100 cycles is Q = Q 100 / Q1×100%.

[0232] 18. Specific capacity of all solid-state products:

[0233] Fabrication of all-solid-state batteries:

[0234] 1) Preparation of the positive electrode:

[0235] A mixture of lithium-rich manganese-based cathode material, lithium phosphorus sulfur chlorine and conductive carbon black was dry-mixed under inert conditions (humidity <1ppm) at a mass ratio of 60:30:10. The mixture was then ball-milled at 400rpm for 3h. After ball milling, the cathode sheet (120μm thick) was formed by hot rolling (100℃, 15MPa).

[0236] 2) Preparation of the negative electrode:

[0237] A lithium metal foil with a thickness of 45 μm was polished until Ra ≤ 0.1 μm to obtain a negative electrode.

[0238] 3) Solid electrolyte membrane:

[0239] A sulfide solid electrolyte membrane (45 μm thick) was obtained by mixing lithium phosphorus, sulfur, chlorine and polytetrafluoroethylene (PTFE) in a mass ratio of 6:1 and rolling.

[0240] 4) Assembly of all-solid-state batteries:

[0241] By stacking the positive electrode, solid electrolyte membrane, and negative electrode in sequence, an all-solid-state battery is obtained.

[0242] At 45℃, charge the battery to 4.2V at a constant current rate of 0.1C, and then charge it to 0.02mA at a constant voltage rate of 4.2V. The charging capacity at this time is recorded as the first charge specific capacity. After resting for 10 minutes, discharge the battery to 1.9V at a constant current rate of 0.1C. The discharge capacity at this time is recorded as the battery's first discharge specific capacity.

[0243] 19. Rate performance of all-solid-state batteries: At 45℃, charge at a constant current of 0.1C to a voltage of 4.2V, then charge at a constant voltage of 4.2V to a current of 0.02mA. After resting for 10 minutes, discharge at a constant current of 0.1C to a voltage of 1.9V. The capacity at this point is recorded as the discharge capacity at 0.1C. After resting for 10 minutes, charge at a constant current of 1C to a voltage of 4.2V, then charge at a constant voltage of 4.2V to a current of 0.02mA. After resting for 10 minutes, discharge at a constant current of 1C to a voltage of 1.9V. The capacity at this point is recorded as the discharge capacity at 1C. The ratio of the discharge capacity at 1C to the discharge capacity at 0.1C is the 1C rate performance.

[0244] 20. Cyclic performance of the all-solid-state battery: Under 45℃ conditions, it is charged at a constant current of 1C to 4.2V, then charged at a constant voltage of 4.2V until the current equals 0.02mA, and then discharged at a discharge rate of 1C to 1.9V. This charge-discharge cycle is repeated 100 times. The discharge capacity Q1 at the first cycle and the discharge capacity Q at the 100th cycle are measured. 100 The capacity retention rate after 100 cycles is Q = Q 100 / Q1×100%.

[0245] Figure 1 The image is a SEM image of the lithium-rich manganese-based cathode material of Example 1 provided by the present invention, magnified at 100,000 times.

[0246] from Figure 1 It can be seen that the lithium-rich manganese-based cathode material in Example 1 has a second coating layer with island-like coating on its surface.

[0247] Figure 2 The image is a 10,000x magnified SEM image of the lithium-rich manganese-based cathode material of Example 1 provided by the present invention.

[0248] from Figure 2 It can be seen that the lithium-rich manganese-based cathode material in Example 1 has good dispersibility.

[0249] Figure 4 XRD patterns of lithium-rich manganese-based cathode materials from Examples 1-3 and Comparative Example 1 provided by the present invention.

[0250] from Figure 4 It can be seen that after LATP was coated in Examples 1 and 2, the characteristic peak of LATP appeared at 2θ=24.55 in the lithium-rich manganese-based cathode material, while in Example 3, no LATP was coated and no characteristic peak of LATP appeared.

[0251] Compared to Comparative Example 1, the diffraction peaks corresponding to the (003) crystal plane in Examples 1-3 all show a certain degree of left shift, shifting from 18.8° to 18.72°. This is because strong ionic MO bonds are formed in the lattice of the lithium-rich manganese-based cathode material, and their large ionic radius causes the c-axis to expand, which is shown in the XRD pattern as the diffraction peaks shifting to a lower angle.

[0252] Figure 5 A cross-sectional SEM image of the lithium-rich manganese-based cathode material of Example 1 provided by the present invention.

[0253] Figure 6 EDS diagram of Ni element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention.

[0254] Figure 7 EDS diagram of Co element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention.

[0255] Figure 8 EDS diagram of Mn element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention.

[0256] Figure 9 EDS diagram of O element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention.

[0257] Figure 10 EDS diagram of Ba element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention.

[0258] Figure 11 EDS diagram of Ti element in the lithium-rich manganese-based cathode material of Example 1 provided by the present invention.

[0259] from Figures 5-11 As can be seen, the distribution of each element in the lithium-rich manganese-based cathode material of Example 1 is relatively uniform.

[0260] Figure 12 SEM image of the lithium-rich manganese-based cathode material of Comparative Example 1 provided by the present invention.

[0261] from Figure 12 As can be seen from the data, the lithium-rich manganese-based cathode material matrix of Comparative Example 1 was not doped in any way, and the particle size of the lithium-rich manganese-based cathode material was relatively large.

[0262] Figure 13 SEM image of the lithium-rich manganese-based cathode material of Example 2 provided by the present invention.

[0263] from Figure 13 As can be seen from the data, the lithium-rich manganese-based cathode material in Example 2 has poor dispersion.

[0264] Figure 14SEM image of the lithium-rich manganese-based cathode material of Example 3 provided by the present invention.

[0265] from Figure 14 As can be seen, the lithium-rich manganese-based cathode material in Example 3 does not have island-like coatings of LATP on its surface.

[0266] Table 1

[0267]

[0268] Table 2

[0269]

[0270] Table 3

[0271]

[0272] Table 4

[0273]

[0274] Table 5

[0275]

[0276] Table 6

[0277]

[0278] Table 7

[0279]

[0280] Table 8

[0281]

[0282] As shown in Tables 1-8, compared with the comparative examples, the lithium-rich manganese-based cathode material provided by the present invention can improve the specific capacity, rate performance and cycle performance of the battery by doping two elements with specific ionic radii and ionic electronegativity into the lithium-rich manganese-based cathode material matrix.

[0283] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A lithium-rich manganese-based positive electrode material, characterized in that, The lithium-rich manganese-based positive electrode material base body has a chemical formula of: x(Li2MnO3)·y(LiNi a Co b Mn c M d Q e A k O2), wherein 0 The ion radius of Q is 54-80 pm, and the ion electronegativity is 1.3-2.

1.

2. The lithium-rich manganese-based positive electrode material according to claim 1, characterized in that, The M comprises at least one of Ba 2+ , K + , Rb + , Cs + . and / or the Q comprises at least one of Ti 4+ , Sb 3+ , Mg 2+ , Zn 2+ . And / or, in the X-ray diffraction pattern, the 2θ angle of the diffraction peak corresponding to the (003) crystal face of the lithium-rich manganese-based positive electrode material is 18.2-19.2°; And / or, the half-peak width of the diffraction peak corresponding to the (003) crystal face of the lithium-rich manganese-based positive electrode material is 0.1-0.18°; And / or, the half-peak width of the diffraction peak corresponding to the (104) crystal face of the lithium-rich manganese-based positive electrode material is 0.2-0.26°; And / or, the interlayer spacing d(003) of the (003) crystal face of the lithium-rich manganese-based positive electrode material is 0.47-0.495 nm; And / or, the interlayer spacing d(104) of the (104) crystal face of the lithium-rich manganese-based positive electrode material is 0.19-0.215 nm; And / or, the intensity ratio of the diffraction peak corresponding to the (003) crystal face to the diffraction peak corresponding to the (104) crystal face of the lithium-rich manganese-based positive electrode material is 1.5≤I(003) / I(104)≤2. 3.The lithium-rich manganese-based cathode material of claim 1 or 2, characterized in that, The M occupies the transition metal site; And / or, the Q occupies the Li site and / or the O site.

4. The lithium-rich manganese-based positive electrode material according to any one of claims 1 to 3, characterized in that, The lithium-rich manganese-based positive electrode material further comprises a first coating layer coated on at least part of the surface of the lithium-rich manganese-based positive electrode material matrix; Preferably, the first coating layer comprises a lithium-containing compound; Preferably, the first cladding layer comprises at least one of Li2SiO3, Li2WO4, Li3PO4, Li2B2O4, Li4Ti5O 12 2, LiAlO2. The first coating layer comprises a monoclinic structure with a P21 / c or P21 / n space group structure.

5. The lithium-rich manganese-based positive electrode material according to claim 4, characterized in that, The lithium-rich manganese-based positive electrode material further comprises a second coating layer coated on at least part of the surface of the first coating layer; Preferably, the second coating layer comprises a fast ion conductor.

6. The lithium-rich manganese-based positive electrode material according to claim 5, characterized in that, LiAlTi(PO4)3, Li7La3Zr2O 12 , Li 1.3 Al 0.1 Sc 0.2 Ti 1.7 (PO4)3, Li3Zr2Si2PO 12 ; And / or, the coverage of the first coating layer is ≥90%; And / or, the coverage of the second coating layer is 3-30%; And / or, the thickness of the first coating layer is 1-5 nm; And / or, the thickness of the second coating layer is 0.01-1 nm.

7. The lithium-rich manganese-based positive electrode material according to any one of claims 1 to 6, characterized in that, The mass content of the M in the lithium-rich manganese-based positive electrode material is 2000-10000 ppm; And / or, the mass content of the Q in the lithium-rich manganese-based positive electrode material is 2000-15000 ppm; Preferably, the absolute value of the difference between the mass contents of the Q and the M is 0-5000 ppm.

8. The lithium-rich manganese-based positive electrode material according to any one of claims 1 to 7, characterized in that, The lithium-rich manganese-based positive electrode material comprises primary particles, and the diameter of the primary particles is 0.1-0.5 μm; And / or, the lithium-rich manganese-based positive electrode material is a quasi-single crystal material; And / or, the pH value of the lithium-rich manganese-based positive electrode material is <11, and the residual alkali content is ≤1000 ppm; And / or, the Dv10 of the lithium-rich manganese-based positive electrode material is 0.5-2.2 μm, the Dv50 is 1-5 μm, and the Dv90 is 5-7 μm; And / or, the Span value of the lithium-rich manganese-based positive electrode material is 0.5-2, preferably 0.8-1.

5. and / or the lithium-rich manganese-based positive electrode material has an electrical conductivity of 1 x 10 -8 ~1 x 10 -2 S / cm; and / or the lithium-rich manganese-based positive electrode material has a resistivity of 1 x 10 2 Ω·cm; and / or 6 Ω·cm. And / or, the lithium-rich manganese-based positive electrode material has a specific surface area of 1-4 m 2 / g.

9. A battery, characterized by The battery comprises a full solid-state battery; the full solid-state battery comprises an electrolyte and a negative electrode; 10. The battery of claim 9, wherein, The electrolyte comprises at least one of a polymer solid-state electrolyte, an oxide solid-state electrolyte, a sulfide solid-state electrolyte, and a halide solid-state electrolyte; And / or, the negative electrode comprises at least one of a carbon-based negative electrode, a silicon-based negative electrode, a titanium-based negative electrode, and a lithium metal negative electrode. ​

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