A lithium-rich manganese-based material with high ion channels and high stable surface and a preparation method thereof, and a lithium ion battery

Abstract

This invention provides a lithium-rich manganese-based material with high ion channels and a highly stable surface, its preparation method, and a lithium-ion battery, relating to the field of battery cathode material preparation technology. The surface of the lithium-rich manganese-based material is sequentially coated with spinel Li4Mn5O. 12 The invention comprises a composite layer of polydopamine and a fast ion conductor. The three-dimensional lithium transport channel and stable surface composite bonding enhance structural stability, utilizing the zero-strain material Li4Mn5O. 12 The in-situ introduction of the structure not only provides a lithium-ion transport channel, but also acts as a transition layer between the matrix material and polydopamine, avoiding the peeling of the coating layer from the matrix material after long-term cycling, and significantly improving the cycle life of the material.

Description

Technical Field

[0001] This invention relates to the field of battery cathode material preparation technology, and in particular to a lithium-rich manganese-based material with high ion channels and a highly stable surface, its preparation method, and a lithium-ion battery. Background Technology

[0002] Layered lithium-rich manganese cathodes, with their high specific capacity, low cost, and high safety, have become a key research focus for next-generation cathode materials in lithium-ion batteries. Their high manganese, low nickel, and cobalt-free elemental composition effectively circumvents the constraints of nickel and cobalt resources, aligning with my country's resource advantages of being rich in manganese but poor in nickel. However, their commercialization is hampered by low initial coulombic efficiency, poor rate performance, and limited cycle life.

[0003] Studies have found that lithium-rich manganese-based materials undergo a transformation of their surface structure into a spinel phase after long-term charge-discharge cycles, accompanied by a change in the valence of some manganese from Mn... 4+ Reduced to Mn 3+ The latter exhibits the Ginger-Taylor effect and is prone to disproportionation reactions to form Mn. 2+ Dissolving in the electrolyte causes particle surface pulverization, creating new surfaces and continuing to dissolve, ultimately leading to severe particle decomposition and electrochemical performance degradation. Constructing a stable surface layer is crucial for improving material structural stability, effectively preventing structural phase transitions and oxygen evolution, and enhancing the electrode / electrolyte interface stability. Surface coating can effectively improve the stability of the material's surface structure: fast ion conductor coatings (such as lithium phosphate and lithium sulfate) provide stable lithium-ion transport channels, improving the material's rate performance; inert oxide coatings (such as Al₂O₃ and ZrO₂) isolate the electrolyte from direct contact with the material, preventing corrosion from harmful substances like HF.

[0004] For example, Chinese patent CN115132998A discloses a lithium-rich manganese-based cathode material with surface structure reorganization, whose surface modification layer is a 10-30 nm Li4Mn5O 12The surface layer possesses three-dimensional fast lithium-ion transport channels and oxygen vacancies, significantly improving initial coulombic efficiency and rate performance. However, the hydrothermal process used is relatively expensive. Chinese patent CN118545770A discloses a layered lithium-rich manganese cathode material coated with polydopamine, which significantly improves the discharge specific capacity of the battery at high temperatures and suppresses capacity decay at high temperatures, exhibiting excellent high-temperature performance. However, the polydopamine layer may hinder lithium-ion transport, thus affecting rate performance. A single type of coating layer generally cannot achieve all performance characteristics simultaneously; multifunctional coating layers must be designed and constructed. For example, Chinese patent CN 109659538A discloses a lithium-rich manganese-based oxide material coated with dopamine and lithium phosphate, exhibiting high discharge specific capacity and excellent rate performance. However, modified materials obtained by traditional coating methods have weak interfacial contact between the coating layer and the substrate material, which may peel off after long-term cycling, thus affecting cycle life. Summary of the Invention

[0005] To address the above problems, this invention provides a lithium-rich manganese-based material with efficient ion channels and a stable surface layer. The outermost layer is a composite layer of polydopamine and fast ion conductors. The fast ion conductors are distributed in a dotted pattern within the dense dopamine coating layer. Dopamine can alleviate the volume expansion of the lithium-rich manganese-based material during lithium-ion insertion / extraction and improve structural stability. The dotted fast ion conductors can provide lithium-ion transport channels and improve the rate performance of the material. The next outermost layer is an in-situ formed spinel Li4Mn5O. 12 Layer, Li4Mn5O 12 It is a "zero-strain" material with three-dimensional lithium-ion channels, which improves lithium transport efficiency while mitigating volume expansion and contraction, simultaneously enhancing cycle stability and rate performance. Simultaneously, in-situ formed Li4Mn5O... 12 The layer exhibits good lattice matching with the substrate material, and as a transition layer between the substrate and dopamine, it can prevent coating delamination that may occur during long-term cycling. Furthermore, compared to traditional low-manganese (Mn) materials… 3+ The different valence states of spinel induce different Jamin-Taylor effects, Li4Mn5O 12 The Mn in the solution has a +4 valence, which can significantly mitigate the Jameer-Taylor effect and disproportionation reaction, and reduce Mn levels during material recycling. 2+ The formation and dissolution of [something].

[0006] One of the objectives of this invention is to provide a lithium-rich manganese-based material with high ion channels and a highly stable surface.

[0007] The second objective of this invention is to provide a method for preparing the lithium-rich manganese-based material with high ion channels and a highly stable surface.

[0008] A third objective of this invention is to provide a lithium-ion battery comprising the lithium-rich manganese-based material having high ion channels and a highly stable surface.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0010] In a first aspect, the present invention provides a lithium-rich manganese-based material with high ion channels and a highly stable surface, the structure of which is as follows: Figure 1 As shown, from the inside out, it consists of a bulk phase, a sub-surface layer, and a surface layer. The bulk phase is a layered lithium-rich manganese-based material, and the sub-surface layer is a spinel-structured Li4Mn5O. 12 The surface layer is a composite layer of polydopamine and fast ion conductor.

[0011] In some embodiments, the general chemical formula of the lithium-rich manganese-based material is xLi2MnO3·(1-x)LiMO2, where 0.1≤x≤0.9, and M is one or more of Ni, Co, Mn, Cr, Fe, Ti, Mo, Ru, V, Nb, Zr, and Sn;

[0012] In some embodiments, the fast ion conductor is at least one of lithium sulfate, lithium phosphate, lithium pyrophosphate, lithium niobate, lithium vanadate, lithium silicate, and lithium aluminate.

[0013] In some embodiments, the thickness of the sublayer is 1-5 nm, preferably 2-3 nm, and the thickness of the surface layer is 5-20 nm, preferably 5-6 nm.

[0014] Secondly, the present invention provides a method for preparing lithium-rich manganese-based materials with high ion channels and high surface stability, comprising the following steps:

[0015] (1) Dissolve lithium-rich manganese-based materials, dopamine and coating raw materials in tris(hydroxymethyl)aminomethane buffer solution and adjust the pH of the system to 8±1.

[0016] (2) Stir the mixture obtained in step (1), then filter, wash and dry to obtain a solid.

[0017] (3) The solid obtained in step (2) is placed in a furnace and heat-treated by introducing an oxygen-containing atmosphere. After cooling, a lithium-rich manganese-based material with high ion channels and a highly stable surface is obtained.

[0018] Step (1):

[0019] The amount (mass) of dopamine added in step (1) is 0-10% of the mass of the lithium-rich manganese-based material, and is not 0.

[0020] The coating material in step (1) is at least one of the following: ammonium sulfate, ammonium phosphate, diamine hydrogen phosphate, ammonium dihydrogen phosphate, potassium phosphate, sodium phosphate, potassium niobate, sodium niobate, potassium pyrophosphate, sodium pyrophosphate, potassium vanadate, sodium vanadate, potassium silicate, sodium silicate, potassium aluminate, and sodium aluminate.

[0021] The amount of coating material added in step (1) (calculated in terms of the molar amount of anions) is 0-200% of the molar amount of lithium-rich manganese-based material, and is not 0;

[0022] Step (2):

[0023] The stirring time in step (2) is 1-5 hours.

[0024] Step (3):

[0025] The oxygen-containing atmosphere in step (3) is air or oxygen, the heat treatment temperature is 150-450℃, and the heat treatment time is 0.5-5 hours.

[0026] When dopamine is added and the sintering temperature is increased (or an inert atmosphere is used), the reducing environment created by dopamine carbonization reduces the metal elements on the surface of lithium-rich manganese-based materials, leading to a decrease in the manganese valence state in the formed spinel, thus forming LiMn2O4 (Mn valence is +3.5). However, in this invention, low-temperature air sintering is used, resulting in the formation of Li4Mn5O4. 12 (Mn oxidation state is +4) is a necessary condition for spinel. From the perspective of crystal structure and JT effect, the latter has stronger structural stability.

[0027] This invention provides a one-step method for obtaining Li4Mn5O based on the in-situ polymerization of dopamine. 12 A composite coating layer on the surface of spinel and fast plasma.

[0028] Thirdly, the present invention provides a lithium-ion battery comprising a positive electrode, a negative electrode, and an electrolyte, wherein the positive electrode comprises the aforementioned lithium-rich manganese-based material having high ion channels and a highly stable surface.

[0029] Beneficial effects:

[0030] (1) The lithium-rich manganese-based material with efficient ion channels and a stable surface layer disclosed in this invention has excellent electrochemical performance, achieving a high-rate discharge of 15C and a capacity retention of up to 90% after 500 cycles. This is mainly due to the three-dimensional lithium transport channels and stable surface composite bonding, which enhance structural stability. The "zero-strain" material Li4Mn5O 12 The in-situ introduction of the structure not only provides a lithium-ion transport channel, but also acts as a transition layer between the matrix material and polydopamine, avoiding the peeling of the coating layer from the matrix material after long-term cycling, and significantly improving the cycle life of the material.

[0031] (2) The method used in this invention is simple and mild, requiring only low-temperature treatment at 150-450℃ in air atmosphere, resulting in low process cost and suitability for industrial mass production.

[0032] The present invention has been described in detail above; however, the above embodiments are merely illustrative in nature and are not intended to limit the invention. Furthermore, this document is not limited to the foregoing prior art or the invention itself, or to any theory described in the following embodiments. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the present invention;

[0034] Figure 2 This is a high-resolution transmission electron microscope image of Example 1;

[0035] Figure 3 This is a high-resolution transmission electron microscope image of Comparative Example 1;

[0036] Figure 4 The XRD patterns of Example 1 and Comparative Example 1 are shown below.

[0037] Figure 5 The Raman spectra of Example 1 and Comparative Example 1 are shown below;

[0038] Figure 6 The XRD pattern is shown in Comparative Example 4;

[0039] Figure 7 XPS spectra (Mn 2p) for Example 1 and Comparative Example 1;

[0040] Figure 8 The XPS plot (Mn 2p) is shown in Comparative Example 3.

[0041] Figure 9 XPS spectra (S2p) for Example 1 and Comparative Example 1;

[0042] Figure 10 The discharge specific capacity at different rates for Example 1 and Comparative Example 1;

[0043] Figure 11 The cycling performance of Example 1 and Comparative Example 1;

[0044] Figure 12 This refers to the cyclic performance of Example 2. Detailed Implementation

[0045] The present invention will be further described below with reference to the embodiments. It should be noted that the following embodiments are provided for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0046] Unless otherwise specified, the raw materials, reagents, and methods used in the embodiments are all conventional raw materials, reagents, and methods in the art.

[0047] Preparation Example

[0048] The preparation process of our company's independently developed lithium-rich manganese-based cathode raw material GL-R1:

[0049] (1) Weigh manganese sulfate, nickel sulfate and cobalt sulfate according to the stoichiometric ratio of lithium-rich manganese-based solution and dissolve them in deionized water to obtain a metal salt solution. Dissolve sodium hydroxide in deionized water to obtain a precipitant solution. Mix the above metal salt solution and sodium hydroxide solution and react at 50°C to obtain a suspension. After washing, filtering and drying, a manganese-cobalt-nickel coprecipitate precursor is obtained.

[0050] (2) Weigh out the manganese-cobalt-nickel coprecipitation precursor and lithium carbonate (calculated as lithium) at a molar ratio of 1:1.18, mix them uniformly, and then heat them to 550℃ at a heating rate of 3℃ / min. Hold the mixture at this temperature for 5 hours, and then continue heating at the same rate to 900℃. Hold the mixture at this temperature for 12 hours. The sintering process is carried out in an air atmosphere. After cooling to room temperature, the polycrystalline lithium-rich manganese-based material Li is obtained. 1.18 Mn 0.52 Co 0.15 Ni 0.15 O2.

[0051] Example 1

[0052] 2g of lithium-rich manganese-based cathode material GL-R1, 0.03g of dopamine, and 5g of ammonium sulfate were dissolved in 20mL of tris(hydroxymethyl)aminomethane buffer. A trace amount of hydrochloric acid was added to adjust the pH of the system to 8.5. The mixture was stirred at room temperature for 1 hour, washed and filtered three times with deionized water, and then vacuum dried. The dried sample was placed in a muffle furnace and air was introduced. The temperature was increased to 375℃ at a rate of 3℃ / min and held for 2 hours. After naturally cooling to room temperature, a lithium sulfate and polydopamine composite with a sub-surface layer and a Li-based composite were obtained. 4 Mn5O 12 Lithium-rich manganese-based materials with spinel layers.

[0053] Example 2

[0054] 2g of lithium-rich manganese-based cathode material GL-R1, 0.03g of dopamine, and 5g of ammonium sulfate were dissolved in 20mL of tris(hydroxymethyl)aminomethane buffer. A trace amount of hydrochloric acid was added to adjust the pH of the system to 8.5. The mixture was stirred at room temperature for 1 hour, washed and filtered three times with deionized water, and then vacuum dried. The dried sample was placed in a muffle furnace and air was introduced. The temperature was increased to 450℃ at a rate of 3℃ / min and held for 2 hours. After naturally cooling to room temperature, a lithium sulfate and polydopamine composite with a sub-surface layer of Li4Mn5O was obtained. 12 Lithium-rich manganese-based materials with spinel layers.

[0055] Example 3

[0056] 2g of lithium-rich manganese-based cathode material GL-R1, 0.03g of dopamine, and 5g of potassium niobate were dissolved in 20mL of tris(hydroxymethyl)aminomethane buffer. A trace amount of hydrochloric acid was added to adjust the pH of the system to 8.5. The mixture was stirred at room temperature for 1 hour, washed and filtered three times with deionized water, and then vacuum dried. The dried sample was placed in a muffle furnace and air was introduced. The temperature was increased to 375℃ at a rate of 3℃ / min and held for 2 hours. After naturally cooling to room temperature, a lithium sulfate and polydopamine composite with a sub-surface layer of Li4Mn5O was obtained. 12 Lithium-rich manganese-based materials with spinel layers.

[0057] Example 4

[0058] 2g of lithium-rich manganese-based cathode material GL-R1, 0.03g of dopamine, and 5g of potassium orthovanadate were dissolved in 20mL of tris(hydroxymethyl)aminomethane buffer. A trace amount of hydrochloric acid was added to adjust the pH of the system to 8.5. The mixture was stirred at room temperature for 1 hour, washed and filtered three times with deionized water, and then vacuum dried. The dried sample was placed in a muffle furnace and air was introduced. The temperature was increased to 375℃ at a rate of 3℃ / min and held for 2 hours. After naturally cooling to room temperature, a lithium sulfate and polydopamine composite with a sub-surface layer of Li4Mn5O was obtained. 12 Lithium-rich manganese-based materials with spinel layers.

[0059] Example 5

[0060] 2g of lithium-rich manganese-based cathode material GL-R1, 0.03g of dopamine, and 4.6g of potassium aluminate were dissolved in 20mL of tris(hydroxymethyl)aminomethane buffer. A trace amount of hydrochloric acid was added to adjust the pH of the system to 8.5. The mixture was stirred at room temperature for 1 hour, washed and filtered three times with deionized water, and then vacuum dried. The dried sample was placed in a muffle furnace and air was introduced. The temperature was increased to 375℃ at a rate of 3℃ / min and held for 2 hours. After naturally cooling to room temperature, a lithium sulfate and polydopamine composite with a sub-surface layer of Li4Mn5O was obtained. 12 Lithium-rich manganese-based materials with spinel layers.

[0061] Comparative Example 1

[0062] GL-R1, an unmodified lithium-rich manganese-based cathode material.

[0063] Comparative Example 2

[0064] 2g of lithium-rich manganese-based cathode material GL-R1, 0.03g of dopamine, and 5g of ammonium sulfate were dissolved in 20mL of tris(hydroxymethyl)aminomethane buffer solution. A trace amount of hydrochloric acid was added to adjust the pH of the system to 8.5. The mixture was stirred at room temperature for 1 hour, washed and filtered three times with deionized water, and then vacuum dried. The dried sample was placed in a muffle furnace and air was introduced. The temperature was increased to 500℃ at a rate of 3℃ / min and held for 2 hours. The modified lithium-rich manganese-based material was obtained by naturally cooling to room temperature.

[0065] Comparative Example 3

[0066] 2g of lithium-rich manganese-based cathode material raw material GL-R1, 0.03g of dopamine, and 5g of ammonium sulfate were dissolved in 20mL of tris(hydroxymethyl)aminomethane buffer solution. A trace amount of hydrochloric acid was added to adjust the pH of the system to 8.5. The mixture was stirred at room temperature for 1 hour, washed and filtered three times with deionized water, and then vacuum dried. The dried sample was placed in a muffle furnace and nitrogen gas was introduced. The temperature was increased to 375℃ at a rate of 3℃ / min and held for 2 hours. The modified lithium-rich manganese-based material was obtained by naturally cooling to room temperature.

[0067] Comparative Example 4

[0068] 2g of lithium-rich manganese-based cathode material GL-R1, 0.03g of dopamine, and 15g of ammonium sulfate were dissolved in 20mL of tris(hydroxymethyl)aminomethane buffer. A trace amount of hydrochloric acid was added to adjust the pH of the system to 8.5. The mixture was stirred at room temperature for 1 hour, washed and filtered three times with deionized water, and then vacuum dried. The dried sample was placed in a muffle furnace and air was introduced. The temperature was increased to 375℃ at a rate of 3℃ / min and held for 2 hours. After naturally cooling to room temperature, a lithium sulfate and polydopamine composite with a sub-surface layer and a Li-based composite were obtained. 4 Mn5O 12 Lithium-rich manganese-based materials with spinel layers.

[0069] Figure 2 and Figure 3 The images are high-resolution transmission electron microscope images of Example 1 and Comparative Example 1, respectively. It can be seen that the surface and bulk interior of Comparative Example 1 have a layered structure, while Example 1 shows obvious polydopamine and spinel layers.

[0070] Figure 4 and Figure 5 XRD and Raman spectra of Example 1 and Comparative Example 1 are given. The XRD patterns show that Comparative Example 1 exhibits a typical layered structure, while Example 1 shows a spinel peak at a diffraction angle of 43.5°. Figure 5 The Raman spectrum in the image can also prove the existence of the spinel phase.

[0071] Figure 6The XRD patterns of Comparative Example 4 are shown. It can be seen that when the amount of ammonium sulfate added is increased to 15g, the peak appearing near 22.5° in the XRD pattern corresponds to the diffraction peak of Li2SO4. However, excessive addition of ammonium sulfate will affect its performance.

[0072] Figure 7 XPS-Mn-2p spectra of Example 1 and Comparative Example 1 are given. It can be seen that after modification, the binding energy is around 642 eV, corresponding to Mn. 4+ The increased peak percentage indicates that no Mn reduction occurred after treatment, further confirming that the formed spinel phase is high-valence Li4Mn5O. 12 Spinel instead of LiMn2O4 spinel, the latter being more prone to the Ginger-Taylor effect, which degrades material properties.

[0073] Figure 9 XPS-S-2p spectra of Example 1 and Comparative Example 1 are given. It can be seen that after treatment, a 2p peak of S appears at around 168.5 eV, which corresponds to SO4. Combined with XRD, the formation of Li2SO4 can be confirmed.

[0074] In Comparative Example 2, high-temperature sintering in air leads to the oxidative decomposition of the polydopamine layer on the surface, which prevents the formation of the highly stable surface structure described in this invention and affects the cycle life of the material.

[0075] Figure 8 The XPS-Mn-2p spectra of Comparative Example 3 are given. It can be seen that after sintering under an inert atmosphere, the binding energy is around 642 eV, corresponding to Mn. 4+ The proportion decreased to 38.46%, lower than the untreated raw material (43.91%), indicating that Mn was reduced under an inert atmosphere, resulting in a decrease in the average oxidation state. In Comparative Example 3, under inert atmosphere sintering, dopamine was carbonized as a carbon source, leading to a reducing atmosphere on the material surface. This reduced the oxidation state of manganese in the structure, resulting in a higher proportion of Mn in the surface layer. 3+ This affects Li4Mn5O 12 (All are Mn) 4+ The formation of ) affects the rate capability and cycle performance of the material.

[0076] Electrochemical performance testing:

[0077] A slurry is formed by mixing positive electrode active material, acetylene black, polyvinylidene fluoride and N-methylpyrrolidone, and uniformly coating it onto the surface of an aluminum foil sheet to obtain a positive electrode sheet. Then, a lithium sheet is used as the negative electrode sheet, and a 1 mol / L lithium hexafluorophosphate solution of ethylene carbonate (EC) and dimethyl carbonate (DMC) (EC to DMC volume ratio of 1:1) is used as the electrolyte. The assembly is carried out in a glove box to obtain a lithium-ion battery.

[0078] The cycle performance of the lithium-ion battery was tested using an electrochemical testing instrument at a temperature of 25°C and a current density of 0.1C (1C = 200 mAg). -1 The battery's initial charge / discharge performance was tested within a charge / discharge voltage range of 4.8-2.0V. Subsequent charging currents were 0.2C, and discharge currents of 1C, 3C, 5C, 10C, and 15C were used to test the discharge specific capacity at different rates. Cycle performance was tested under a 2.0-4.8V, 1C / 1C regime.

[0079] Negative electrode Mn content test:

[0080] After cycling, the button cells were disassembled in a glove box, dried, and the powder on the positive electrode was scraped off. The manganese content in the powder was tested using the ICP method according to the national standard GB / T 23942-2009.

[0081] The results are shown in Table 1.

[0082] Table 1 Comparison of electrochemical performance between the examples and comparative examples

[0083]

[0084] Figure 10 and Figure 11 The rate capability and cycling performance of Example 1 and Comparative Example 1 are given respectively. Figure 12 The cycling performance of Example 2 is given, and it can be seen that the electrochemical performance of the lithium-rich manganese-based material with efficient ion channels and a stable surface layer proposed in this invention is significantly improved.

[0085] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and substance defined by the claims of the present invention; and such modifications or substitutions are still within the scope defined by the claims of the present invention.

Claims

1. A lithium-rich manganese-based material with high ion channels and a highly stable surface, characterized in that, The structure of the lithium-rich manganese-based material, from the inside out, includes a bulk phase, a sub-surface layer, and a surface layer. The bulk phase is a layered lithium-rich manganese-based material, and the sub-surface layer is a spinel-structured Li4Mn5O. 12 The surface layer is a composite layer of polydopamine and fast ion conductor; The method for preparing the lithium-rich manganese-based material with high ion channels and high surface stability includes the following steps: (1) Dissolve lithium-rich manganese-based materials, dopamine and coating raw materials in tris(hydroxymethyl)aminomethane buffer solution and adjust the pH of the system to 8±1; (2) Stir the mixture obtained in step (1), then filter, wash and dry to obtain a solid. (3) The solid obtained in step (2) is placed in a furnace and heat-treated by passing an oxygen-containing atmosphere. After cooling, a lithium-rich manganese-based material with high ion channels and a highly stable surface is obtained. The oxygen-containing atmosphere in step (3) is air or oxygen, the heat treatment temperature is 150-450℃, and the heat treatment time is 0.5-5 hours.

2. The lithium-rich manganese-based material with high ion channels and a highly stable surface according to claim 1, characterized in that, The general chemical formula of the lithium-rich manganese-based material is xLi2MnO3·(1-x)LiMO2, where 0.1≤x≤0.9, and M is one or more of Ni, Co, Mn, Cr, Fe, Ti, Mo, Ru, V, Nb, Zr and Sn.

3. The lithium-rich manganese-based material with high ion channels and a highly stable surface according to claim 1, characterized in that, The fast ion conductor is at least one of lithium sulfate, lithium phosphate, lithium pyrophosphate, lithium niobate, lithium vanadate, lithium silicate, and lithium aluminate.

4. The lithium-rich manganese-based material with high ion channels and a highly stable surface according to claim 1, characterized in that, The thickness of the sublayer is 1-5 nm, and the thickness of the surface layer is 5-20 nm.

5. The lithium-rich manganese-based material with high ion channels and a highly stable surface according to claim 1, characterized in that, The amount of dopamine added in step (1) is 0%-10% of the mass of the lithium-rich manganese-based material, and is not 0.

6. The lithium-rich manganese-based material with high ion channels and a highly stable surface according to claim 1, characterized in that, The coating material in step (1) is at least one of the following: ammonium sulfate, ammonium phosphate, diamine hydrogen phosphate, ammonium dihydrogen phosphate, potassium phosphate, sodium phosphate, potassium niobate, sodium niobate, potassium pyrophosphate, sodium pyrophosphate, potassium vanadate, sodium vanadate, potassium silicate, sodium silicate, potassium aluminate, and sodium aluminate. In step (1), the amount of coating material added is calculated as 0-200% of the molar amount of lithium-rich manganese-based material based on the molar amount of anions, and is not 0.

7. The lithium-rich manganese-based material with high ion channels and a highly stable surface according to claim 1, characterized in that, The stirring time in step (2) is 1-5 hours.

8. A lithium-ion battery, characterized in that, It includes a positive electrode, a negative electrode, and an electrolyte, wherein the positive electrode comprises a lithium-rich manganese-based material with high ion channels and a highly stable surface as described in any one of claims 1-7.

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