High-nickel ternary precursor, lithium-rich positive electrode material, and preparation method

Abstract

The present application relates to a high-nickel ternary precursor, a lithium-rich positive electrode material, and a preparation method. The preparation method comprises the following steps: adding a nickel-manganese solution, a titanium-source hydrogen peroxide solution, a precipitant solution, and a complexing agent solution simultaneously into a reaction mother liquor, and performing a co-precipitation reaction to obtain a high-nickel ternary precursor. In the preparation method provided by the present application, by adding Ti during the co-precipitation process and controlling the ratio of Li in the obtained lithium-rich positive electrode material, the capacity and stability of the obtained lithium-rich positive electrode material are improved.

Description

A high-nickel ternary precursor, a lithium-rich cathode material, and a preparation method thereof. Technical Field

[0001] This application belongs to the field of battery technology and relates to a lithium-rich cathode, particularly to a high-nickel ternary precursor, a lithium-rich cathode material, and a preparation method thereof. Background Technology

[0002] Lithium-ion batteries, with their advantages of high energy density and long cycle life, are widely used in electric vehicles, communications, and energy storage, and the energy density requirements for individual cells are becoming increasingly stringent. The cathode material of lithium-ion batteries, as the source and carrier of battery energy, greatly contributes to improving the energy density of lithium-ion batteries. High-nickel ternary cathode materials, in particular, possess the advantages of high specific capacity and high energy density.

[0003] Solid-state batteries offer the advantage of ultra-high energy density, and high-nickel ternary cathode materials are better suited for solid-state battery systems, further enhancing their energy density. However, the stability of high-nickel materials still requires improvement. Conventional improvement methods often involve adding a coating layer to enhance stability, but these methods cannot address the inherent instability of the material.

[0004] To address this, it is necessary to improve the intrinsic stability of lithium-rich cathode materials with high nickel content, and to provide a high-nickel ternary precursor, a lithium-rich cathode material, and a preparation method accordingly. Summary of the Invention

[0005] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0006] To address the shortcomings of existing technologies, the purpose of this application is to provide a high-nickel ternary precursor, a lithium-rich cathode material, and a preparation method thereof. The high-nickel ternary precursor, by setting the Ti content and coordinating it with the lithium content in the lithium-rich cathode material, improves the capacity and stability of the resulting lithium-rich cathode material.

[0007] To achieve this objective, the present application adopts the following technical solution:

[0008] In a first aspect, this application provides a method for preparing a high-nickel ternary precursor, the method comprising the following steps:

[0009] A nickel-manganese solution, a titanium-sourced hydrogen peroxide solution, a precipitant solution, and a complexing agent solution were added concurrently to the reaction substrate to coprecipitate the high-nickel ternary precursor.

[0010] The chemical formula of the high-nickel ternary precursor is Ni 0.9 Mn x Ti y(OH)2, where 0.02≤x≤0.08, 0.01≤y≤0.04.

[0011] The method for preparing the high-nickel ternary precursor provided in this application uses a titanium-source hydrogen peroxide solution for titanium doping during the co-precipitation process. Titanium ions have a relatively large radius; titanium doping into the high-nickel ternary cathode material increases the lithium-oxygen layer, providing a wider channel for lithium ion insertion and extraction, reducing the diffusion resistance of lithium ions in the electrode material, thereby improving the lithium ion migration rate and capacity. Furthermore, high titanium doping content can form a lithium-rich structure with excess lithium, allowing the material to accommodate more lithium while improving structural stability, thus enhancing the cycle stability of the lithium-rich cathode material. Therefore, the preparation method provided in this application, by adding Ti during the co-precipitation process and controlling the Li ratio in the resulting lithium-rich cathode material, improves the capacity and stability of the obtained lithium-rich cathode material.

[0012] In one embodiment, the titanium source in the titanium source hydrogen peroxide solution includes titanium sulfate and / or titanium oxysulfate.

[0013] In one embodiment, the concentration of hydrogen peroxide in the titanium source hydrogen peroxide solution is 20wt%-30wt%.

[0014] In one embodiment, the molar concentration of titanium in the titanium source hydrogen peroxide solution is 0.1 mol / L to 0.3 mol / L.

[0015] In one embodiment, the concentration of the nickel-manganese solution is 2 mol / L to 4 mol / L.

[0016] In one embodiment, the nickel source in the nickel-manganese solution includes any one or a combination of at least two of nickel nitrate, nickel sulfate, or nickel chloride.

[0017] In one embodiment, the manganese source in the nickel-manganese solution includes any one or a combination of at least two of manganese nitrate, manganese sulfate, or manganese chloride.

[0018] In one embodiment, the pH of the reaction substrate is 11-12.

[0019] In one embodiment, the concentration of the complexing agent in the reaction substrate is 0.2 mol / L to 0.5 mol / L.

[0020] In one embodiment, the temperature of the reaction substrate is 40°C-80°C.

[0021] In one embodiment, the pH value of the coprecipitation reaction is 10.5-11.5.

[0022] In one embodiment, during the coprecipitation reaction, the concentration of the complexing agent in the system is 0.1-0.5 mol / L.

[0023] In one embodiment, the temperature of the coprecipitation reaction is 40°C-80°C.

[0024] In one embodiment, the coprecipitation reaction takes 60-100 hours.

[0025] In one embodiment, the coprecipitation reaction is carried out under stirring conditions at a speed of 200 r / min to 400 r / min.

[0026] In one embodiment, the precipitant in the precipitant solution includes sodium hydroxide.

[0027] In one embodiment, the complexing agent in the complexing agent solution includes any one or a combination of at least two of ammonia, citric acid, or sodium citrate.

[0028] Secondly, this application provides a high-nickel ternary precursor, which is prepared by the preparation method described in the first aspect.

[0029] Thirdly, this application provides a method for preparing a lithium-rich cathode material, the method comprising the following steps:

[0030] A mixture of lithium source and the high-nickel ternary precursor described in the second aspect is heat-treated to obtain the lithium-rich cathode material Li. 1+a Ni 0.9 Mn x Ti y O2, where 0.02≤a≤0.08, 0.02≤x≤0.08, and 0.01≤y≤0.04.

[0031] In one embodiment, the heat treatment includes a first heat treatment and a second heat treatment performed sequentially.

[0032] In one embodiment, the temperature of the first heat treatment is 480℃-520℃, and the time is 4.5h-5.5h.

[0033] In one embodiment, the temperature of the second heat treatment is 700℃-900℃, and the time is 10h-16h.

[0034] Fourthly, this application provides a lithium-rich cathode material, which is prepared by the preparation method described in the third aspect.

[0035] The numerical range described in this application includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this application will not exhaustively list the specific point values ​​included in the range.

[0036] Compared with the prior art, this application has the following advantages:

[0037] Titanium ions have a relatively large radius. Titanium doping into high-nickel ternary cathode materials can increase the lithium-oxygen layer, providing a wider channel for lithium ion insertion and extraction, reducing the diffusion resistance of lithium ions in the electrode material, thereby improving the migration rate of lithium ions and increasing capacity. In addition, titanium doping can enhance the bond strength of metal-oxygen bonds, thereby improving the structural stability and the cycle stability of lithium-rich cathode materials. Therefore, the preparation method provided in this application, by adding Ti during the co-precipitation process and controlling the Li ratio in the resulting lithium-rich cathode material, improves the capacity and stability of the resulting lithium-rich cathode material.

[0038] After reading and understanding the detailed description, other aspects can be understood. Detailed Implementation

[0039] The technical solution of this application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely to help understand this application and should not be regarded as specific limitations on this application.

[0040] One embodiment of this application provides a method for preparing a high-nickel ternary precursor, the method comprising the following steps:

[0041] A nickel-manganese solution, a titanium-sourced hydrogen peroxide solution, a precipitant solution, and a complexing agent solution were added concurrently to the reaction substrate to coprecipitate the high-nickel ternary precursor.

[0042] The chemical formula of the high-nickel ternary precursor is Ni 0.9 Mn x Ti y (OH)2, where 0.02≤x≤0.08, 0.01≤y≤0.04.

[0043] Titanium ions have a relatively large radius. Titanium doping into high-nickel ternary cathode materials can increase the lithium-oxygen layer, providing a wider channel for lithium ion insertion and extraction, reducing the diffusion resistance of lithium ions in the electrode material, thereby improving the migration rate of lithium ions and increasing capacity. In addition, titanium doping can enhance the bond strength of metal-oxygen bonds, thereby improving the structural stability and the cycle stability of lithium-rich cathode materials. Therefore, the preparation method provided in this application, by adding Ti during the co-precipitation process and controlling the Li ratio in the resulting lithium-rich cathode material, improves the capacity and stability of the resulting lithium-rich cathode material.

[0044] In some embodiments, the coprecipitation reaction is carried out in a protective atmosphere.

[0045] Optionally, the protective atmosphere may include nitrogen and / or an inert gas.

[0046] The inert gas includes any one or a combination of at least two of helium, neon, or argon. Typical but non-limiting combinations include helium and neon, neon and argon, helium and argon, or helium, neon, and argon.

[0047] In some embodiments, the titanium source in the titanium source hydrogen peroxide solution includes titanium sulfate and / or titanium oxysulfate.

[0048] In some embodiments, the concentration of hydrogen peroxide in the titanium source hydrogen peroxide solution is 20wt%-30wt%, for example, it can be 20wt%, 22wt%, 25wt%, 28wt% or 30wt%, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0049] In some embodiments, the molar concentration of titanium in the titanium source hydrogen peroxide solution is 0.1 mol / L to 0.3 mol / L, for example, it can be 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L or 0.3 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0050] In some embodiments, the concentration of the nickel-manganese solution is 2 mol / L to 4 mol / L, for example, it can be 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L or 4 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0051] In some embodiments, the nickel source in the nickel-manganese solution includes any one or a combination of at least two of nickel nitrate, nickel sulfate, or nickel chloride. Typical but non-limiting combinations include a combination of nickel nitrate and nickel sulfate, a combination of nickel sulfate and nickel chloride, a combination of nickel nitrate and nickel chloride, or a combination of nickel nitrate, nickel sulfate, and nickel chloride.

[0052] In some embodiments, the manganese source in the nickel-manganese solution includes any one or a combination of at least two of manganese nitrate, manganese sulfate, or manganese chloride. Typical but non-limiting combinations include combinations of manganese nitrate and manganese sulfate, manganese sulfate and manganese chloride, manganese nitrate and manganese chloride, and combinations of manganese nitrate, manganese sulfate, and manganese chloride.

[0053] In some embodiments, the pH of the reaction substrate is 11-12, for example, 11, 11.5 or 12, but not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0054] In some embodiments, the pH of the reaction substrate is adjusted using a precipitant solution.

[0055] In some embodiments, the concentration of the complexing agent in the reaction substrate is 0.2 mol / L to 0.5 mol / L, for example, it can be 0.2 mol / L, 0.3 mol / L, 0.4 mol / L or 0.5 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0056] In some embodiments, the temperature of the reaction substrate is 40°C-80°C, for example, it can be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0057] In some embodiments, the pH value of the coprecipitation reaction is 10.5-11.5, for example, it can be 10.5, 11 or 11.5, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0058] In some embodiments, during the coprecipitation reaction, the concentration of the complexing agent in the system is 0.1 mol / L to 0.5 mol / L, for example, it can be 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L or 0.5 mol / L, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0059] In some embodiments, the temperature of the coprecipitation reaction is 40°C-80°C, for example, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C or 80°C, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0060] In some embodiments, the coprecipitation reaction time is 60h-100h, for example, it can be 60h, 70h, 80h, 90h or 100h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0061] In some embodiments, the coprecipitation reaction is carried out under stirring conditions of 200 r / min to 400 r / min, for example, 200 r / min, 250 r / min, 300 r / min, 350 r / min or 400 r / min, but not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0062] In some embodiments, the precipitant in the precipitant solution includes sodium hydroxide.

[0063] In some embodiments, the complexing agent in the complexing agent solution includes any one or a combination of at least two of ammonia, citric acid, or sodium citrate.

[0064] One embodiment of this application provides a high-nickel ternary precursor, which is prepared by the preparation method described in any embodiment.

[0065] One embodiment of this application provides a method for preparing a lithium-rich cathode material, the method comprising the following steps:

[0066] A mixture of lithium source and the high-nickel ternary precursor described in any embodiment is heat-treated to obtain the lithium-rich cathode material Li. 1+a Ni 0.9 Mn x Ti y O2, where 0.02≤a≤0.08, 0.02≤x≤0.08, and 0.01≤y≤0.04.

[0067] In some embodiments, the lithium source includes LiOH and / or Li2CO3.

[0068] In some embodiments, the heat treatment includes a first heat treatment and a second heat treatment performed sequentially.

[0069] In some embodiments, the temperature of the first heat treatment is 480°C-520°C, and the time is 4.5h-5.5h.

[0070] The temperature of the first heat treatment is 480℃-520℃, for example, it can be 480℃, 490℃, 500℃, 510℃ or 520℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0071] The first heat treatment time is 4.5h-5.5h, for example, it can be 4.5h, 4.8h, 5h, 5.2h or 5.5h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0072] In some embodiments, the temperature of the second heat treatment is 700°C-900°C, and the time is 10h-16h.

[0073] The temperature for the second heat treatment is 700℃-900℃, for example, it can be 700℃, 750℃, 800℃, 850℃ or 900℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0074] The second heat treatment time is 10h-16h, for example, it can be 10h, 12h, 14h, 15h or 16h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0075] Some embodiments of this application provide a lithium-rich cathode material, which is prepared by the preparation method described in any embodiment.

[0076] Example 1

[0077] This embodiment provides a lithium-rich cathode material Li 1.06 Ni 0.90 Mn 0.04 Ti 0.03 The preparation method of this lithium-rich cathode material includes the following steps:

[0078] (1) In a nitrogen atmosphere, nickel-manganese solution, titanium-source hydrogen peroxide solution, sodium hydroxide solution and ammonia solution are added in parallel streams to the reaction substrate to obtain a high-nickel ternary precursor Ni through a co-precipitation reaction. 0.90 Mn 0.04 Ti 0.03 (OH)2.

[0079] The reaction substrate was an aqueous solution of sodium hydroxide and ammonia, with a pH of 11.5, an ammonia concentration of 0.3 mol / L, and a temperature of 60℃.

[0080] The nickel source in the nickel-manganese solution is nickel sulfate, and the manganese source is manganese sulfate. The total molar concentration of the nickel and manganese sources is 2 mol / L.

[0081] The titanium source in the titanium-source hydrogen peroxide solution is titanium oxysulfate, the hydrogen peroxide concentration is 23 wt%, and the molar concentration of titanium is 0.3 mol / L.

[0082] The coprecipitation reaction was carried out under stirring conditions at 350 r / min, with a pH of 11, an ammonia concentration of 0.3 mol / L, a temperature of 60℃, and a time of 80 h.

[0083] (2) Mix LiOH with the high-nickel ternary precursor, and perform a first heat treatment and a second heat treatment sequentially, followed by furnace cooling to obtain the lithium-rich cathode material Li. 1.06 Ni 0.90 Mn 0.04 Ti 0.03 O2.

[0084] The first heat treatment was carried out at a temperature of 500℃ for 5 hours; the second heat treatment was carried out at a temperature of 800℃ for 12 hours.

[0085] Example 2

[0086] This embodiment provides a lithium-rich cathode material Li 1.06 Ni 0.90 Mn 0.04 Ti 0.03 The preparation method of this lithium-rich cathode material includes the following steps:

[0087] (1) In a nitrogen atmosphere, nickel-manganese solution, titanium-source hydrogen peroxide solution, sodium hydroxide solution and ammonia solution are added in parallel streams to the reaction substrate to obtain a high-nickel ternary precursor Ni through a co-precipitation reaction. 0.90 Mn 0.04 Ti 0.03 (OH)2.

[0088] The reaction substrate was an aqueous solution of sodium hydroxide and ammonia, with a pH of 11, an ammonia concentration of 0.2 mol / L, and a temperature of 40℃.

[0089] The nickel source in the nickel-manganese solution is nickel sulfate, and the manganese source is manganese sulfate. The total molar concentration of the nickel and manganese sources is 2 mol / L.

[0090] The titanium source in the titanium-source hydrogen peroxide solution is titanium oxysulfate, the hydrogen peroxide concentration is 20 wt%, and the molar concentration of titanium is 0.1 mol / L.

[0091] The coprecipitation reaction was carried out under stirring conditions of 200 r / min, with a pH of 10.5, an ammonia concentration of 0.1 mol / L, a temperature of 40℃, and a time of 100 h.

[0092] (2) Mix LiOH with the high-nickel ternary precursor, and perform a first heat treatment and a second heat treatment sequentially, followed by furnace cooling to obtain the lithium-rich cathode material Li. 1.06 Ni 0.90 Mn 0.04 Ti 0.03 O2.

[0093] The first heat treatment was carried out at a temperature of 480℃ for 5.5 hours; the second heat treatment was carried out at a temperature of 700℃ for 16 hours.

[0094] Example 3

[0095] This embodiment provides a lithium-rich cathode material Li 1.06 Ni 0.90 Mn 0.04 Ti 0.03 The preparation method of this lithium-rich cathode material includes the following steps:

[0096] (1) In a nitrogen atmosphere, nickel-manganese solution, titanium-source hydrogen peroxide solution, sodium hydroxide solution and ammonia solution are added in parallel streams to the reaction substrate to obtain a high-nickel ternary precursor Ni through a co-precipitation reaction. 0.90 Mn 0.04 Ti 0.03 (OH)2.

[0097] The reaction substrate was an aqueous solution of sodium hydroxide and ammonia, with a pH of 12, an ammonia concentration of 0.5 mol / L, and a temperature of 80℃.

[0098] The nickel source in the nickel-manganese solution is nickel sulfate, and the manganese source is manganese sulfate. The total molar concentration of the nickel and manganese sources is 4 mol / L.

[0099] The titanium source in the titanium source hydrogen peroxide solution is titanium oxysulfate, the hydrogen peroxide concentration is 30 wt%, and the molar concentration of titanium is 0.2 mol / L.

[0100] The coprecipitation reaction was carried out under stirring conditions at 400 r / min, with a pH of 11.5, an ammonia concentration of 0.5 mol / L, a temperature of 80℃, and a time of 60 h.

[0101] (2) Mix LiOH with the high-nickel ternary precursor, and perform a first heat treatment and a second heat treatment sequentially, followed by furnace cooling to obtain the lithium-rich cathode material Li. 1.06 Ni 0.90 Mn 0.04 Ti 0.03 O2.

[0102] The first heat treatment was carried out at a temperature of 520℃ for 4.5 hours; the second heat treatment was carried out at a temperature of 900℃ for 10 hours.

[0103] Example 4

[0104] This embodiment provides a lithium-rich cathode material. Besides altering the flow rate of the titanium source hydrogen peroxide solution during the co-precipitation reaction, the chemical formula of the lithium-rich cathode material is changed to Li. 1.02 Ni 0.90 Mn 0.08 Ti 0.01 Except for O2, everything else is the same as in Example 1.

[0105] Example 5

[0106] This embodiment provides a lithium-rich cathode material. Besides altering the flow rate of the titanium source hydrogen peroxide solution during the co-precipitation reaction, the chemical formula of the lithium-rich cathode material is changed to Li. 1.08 Ni 0.90 Mn 0.02 Ti 0.04 Except for O2, everything else is the same as in Example 1.

[0107] Example 6

[0108] This embodiment provides a lithium-rich cathode material. Besides altering the flow rate of the titanium source hydrogen peroxide solution during the co-precipitation reaction, the chemical formula of the lithium-rich cathode material is changed to LiNi. 0.8955 Mn 0.955 Ti 0.005 Except for O2, everything else is the same as in Example 1.

[0109] Example 7

[0110] This embodiment provides a lithium-rich cathode material. Besides altering the flow rate of the titanium source hydrogen peroxide solution during the co-precipitation reaction, the chemical formula of the lithium-rich cathode material is changed to Li. 1.09 Ni 0.90 Mn 0.01 Ti 0.045 Except for O2, everything else is the same as in Example 1.

[0111] Example 8

[0112] This embodiment provides a lithium-rich cathode material, which is the same as in Example 1 except that the hydrogen peroxide concentration in the titanium source hydrogen peroxide solution is 15 wt%.

[0113] Example 9

[0114] This embodiment provides a lithium-rich cathode material, which is the same as in Example 1 except that the hydrogen peroxide concentration in the titanium source hydrogen peroxide solution is 35 wt%.

[0115] Comparative Example 1

[0116] This comparative example provides a lithium-rich cathode material, which is the same as in Example 1 except that no titanium source hydrogen peroxide solution was added during the co-precipitation reaction.

[0117] Performance Characterization

[0118] The positive electrode material, polyvinylidene fluoride, and acetylene black were mixed in a mass ratio of 80:10:10, NMP (N-methylpyrrolidone) was added, and the mixture was stirred to form a slurry. This slurry was then coated onto aluminum foil, dried, and used as the positive electrode. A lithium sheet was used as the negative electrode, and the mixture was assembled into a CR2025 coin cell. Its electrochemical performance was then tested at 2.8-4.4V.

[0119] Table 1

[0120] In summary, titanium ions have a relatively large radius. Titanium doping into high-nickel ternary cathode materials can increase the lithium-oxygen layer, providing a wider channel for lithium ion insertion and extraction, reducing the diffusion resistance of lithium ions in the electrode material, thereby improving the migration rate of lithium ions and increasing capacity. In addition, high titanium doping can form a lithium-rich structure with excess lithium, enabling the material to accommodate more lithium while improving structural stability. Therefore, the preparation method provided in this application, by adding Ti during the co-precipitation process and controlling the Li ratio in the resulting lithium-rich cathode material, improves the capacity and stability of the obtained lithium-rich cathode material.

[0121] The applicant declares that the above description is only a specific implementation of this application, but the protection scope of this application is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application fall within the protection and disclosure scope of this application.

Claims

1. A method for preparing a high-nickel ternary precursor, comprising the following steps: A nickel-manganese solution, a titanium-sourced hydrogen peroxide solution, a precipitant solution, and a complexing agent solution were added concurrently to the reaction substrate to coprecipitate the high-nickel ternary precursor. The chemical formula of the high-nickel ternary precursor is Ni 0.9 Mn x Ti y (OH)2, where 0.02≤x≤0.08, 0.01≤y≤0.

04.

2. The preparation method according to claim 1, wherein, The titanium source in the titanium source hydrogen peroxide solution includes titanium sulfate and / or titanium oxysulfate. And / or, the concentration of hydrogen peroxide in the titanium source hydrogen peroxide solution is 20wt%-30wt%; And / or, in the titanium source hydrogen peroxide solution, the molar concentration of titanium is 0.1 mol / L-0.3 mol / L.

3. The preparation method according to claim 1 or 2, wherein, The concentration of the nickel-manganese solution is 2 mol / L-4 mol / L; And / or, the nickel source in the nickel-manganese solution includes any one or a combination of at least two of nickel nitrate, nickel sulfate, or nickel chloride; And / or, the manganese source in the nickel-manganese solution includes any one or a combination of at least two of manganese nitrate, manganese sulfate, or manganese chloride.

4. The preparation method according to any one of claims 1-3, wherein, The pH value of the reaction substrate is 11-12; And / or, the concentration of the complexing agent in the reaction substrate is 0.2 mol / L-0.5 mol / L; And / or, the temperature of the reaction substrate is 40℃-80℃.

5. The preparation method according to any one of claims 1-4, wherein, The pH value of the coprecipitation reaction is 10.5-11.5; And / or, during the coprecipitation reaction, the concentration of the complexing agent in the system is 0.1 mol / L-0.5 mol / L; And / or, the temperature of the coprecipitation reaction is 40℃-80℃; And / or, the coprecipitation reaction takes 60-100 hours; And / or, the coprecipitation reaction is carried out under stirring conditions of 200 r / min-400 r / min.

6. The preparation method according to any one of claims 1-5, wherein, The precipitant in the precipitant solution includes sodium hydroxide; And / or, the complexing agent in the complexing agent solution includes any one or a combination of at least two of ammonia, citric acid, or sodium citrate.

7. A high-nickel ternary precursor prepared by the preparation method according to any one of claims 1-6.

8. A method for preparing a lithium-rich cathode material, comprising the following steps: A mixture of lithium source and the high-nickel ternary precursor of claim 7 is heat-treated to obtain the lithium-rich cathode material Li. 1+a Ni 0.9 Mn x Ti y O2, where 0.02≤a≤0.08, 0.02≤x≤0.08, and 0.01≤y≤0.

04.

9. The preparation method according to claim 8, wherein, The heat treatment includes a first heat treatment and a second heat treatment performed sequentially. And / or, the temperature of the first heat treatment is 480℃-520℃, and the time is 4.5h-5.5h; And / or, the temperature of the second heat treatment is 700℃-900℃, and the time is 10h-16h.

10. A lithium-rich cathode material prepared by the preparation method of claim 8 or 9.

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