CN113387398A - Ternary positive electrode active material with nano-micro hierarchical structure, precursor, preparation method and application thereof - Google Patents

Ternary positive electrode active material with nano-micro hierarchical structure, precursor, preparation method and application thereof Download PDF

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CN113387398A
CN113387398A CN202010169188.8A CN202010169188A CN113387398A CN 113387398 A CN113387398 A CN 113387398A CN 202010169188 A CN202010169188 A CN 202010169188A CN 113387398 A CN113387398 A CN 113387398A
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active material
positive electrode
ternary
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precursor
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CN113387398B (en
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方静
安浩
王小涵
覃富荣
张凯
张治安
洪波
赖延清
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Central South University
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    • C01G53/50—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [MnO2]n-, e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
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    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
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Abstract

The invention belongs to the field of lithium ion battery anode materials, and particularly relates to a ternary anode composite material precursor with a nano-micro hierarchical structure, and preparation and application thereof. In the invention, a precursor metal source containing the ternary cathode active material, N-dimethylformamide and glycerol mixed solution are subjected to solvent heat treatment, and a precursor of the ternary cathode active material with a dumbbell-shaped appearance is obtained through separation; the volume ratio of the N, N-dimethylformamide to the glycerol is 3-5: 1. And carrying out lithiation sintering on the precursor to obtain the material with the special morphology. The method has the advantages of simple process and low cost, and the controllable lithium-rich manganese-based anode material prepared by the method has uniform element precipitation, and the nano-micro hierarchical structure has good cycle stability and excellent electrochemical performance.

Description

Ternary positive electrode active material with nano-micro hierarchical structure, precursor, preparation method and application thereof
Technical Field
The invention belongs to the technical field of energy storage, and particularly relates to a ternary positive active material precursor with a nano-micro hierarchical structure, and preparation and application thereof.
Background
In recent years, with the development of economy and the advancement of technology, energy problems and environmental problems have become important concerns of all people at present. The excessive consumption of fossil fuels and the growing demand for energy have made the development and utilization of clean energy extremely urgent. The lithium ion secondary battery is used as a preferred power supply in the fields of digital products, electric automobile products and the like at present because of the advantages of high energy density, high working voltage, long cycle life, no pollution and the like.
The anode material is used as a main component of the lithium ion battery and plays a decisive role in the capacity of the lithium ion battery. At present, the capacity of a positive electrode material represented by lithium cobaltate is generally lower than 200mAh/g, and the development of a lithium ion power battery is limited to a great extent by the lower capacity of the positive electrode material. Therefore, it is strategic to develop a high-performance cathode material with high reversible capacity and good cycling stability.
Ternary positive electrode active material such as lithium-rich manganese-based layered positive electrode material xLi2MnO3·(1-x)LiMO2(M＝Mn、Ni、Co)]The lithium ion battery positive electrode material has the advantages of high specific capacity, high energy density, good thermal stability and wider charge-discharge voltage range (2-4.8V), is mainly concerned about manganese with relatively rich resources as the main content, and is considered as a mainstream product of a new generation of lithium ion battery positive electrode material. However, the high capacity of lithium-rich manganese-based materials is all higherThe material is obtained under low multiplying power (0.05C), the material has poor circulation stability, the first-turn efficiency is low, the problems of phase change, poor multiplying power performance and the like exist in the circulation process, and the application of the material in practice is influenced. The material morphology and structure can directly influence the electrochemical performance of the material, and the conventional preparation methods such as a high-temperature solid phase method, a sol-gel method, a coprecipitation method and the like are difficult to control the morphology and the characteristic of the product, and the methods have high energy consumption and long time consumption in the using process. In addition, the lithium-rich manganese-based positive electrode material belongs to a multi-element multi-phase complex system, and is difficult to naturally form a material with a special appearance under a specific condition, and simultaneously ensures the uniform distribution of all elements in molecular levels in the material.
Therefore, it is urgently needed to develop a simple preparation method to realize controllable synthesis of the morphology of the positive active material, and solve the problems of high energy consumption, long time consumption and difficulty in controlling the morphology characteristics of the product in the preparation process in the prior art.
Disclosure of Invention
In order to solve the above technical problems, an object of the present invention is to provide a ternary positive electrode active material of a nano-micro level structure (also referred to as a ternary positive electrode active material of a dumbbell-shaped nano-micro level structure, or simply referred to as a ternary positive electrode active material). Aims to provide a brand new ternary cathode active material with special dumbbell shape and excellent electrochemical performance.
The second objective of the present invention is to provide a method for preparing a precursor of a ternary cathode active material with a nano-micro hierarchical structure (also referred to as a dumbbell-shaped precursor or simply a precursor), wherein only one precursor material with a special dumbbell shape is prepared.
The third objective of the present invention is to provide a method for preparing the ternary cathode active material with nano-micro hierarchical structure, which aims to prepare the ternary cathode active material with special morphology.
The fourth purpose of the invention is to provide an application method of the ternary positive electrode active material with the nano-micro hierarchical structure.
A fifth object of the present invention is to provide a positive electrode material, a positive electrode, and a lithium ion battery, each of which contains the ternary positive electrode active material having a nano-micro hierarchical structure.
A ternary positive electrode active material with a nano-micro hierarchical structure has a dumbbell-shaped appearance. The material with the dumbbell-shaped secondary morphology is preferably assembled by a primary structure of the ternary cathode active material.
The invention provides a ternary positive electrode active material with a dumbbell shape. The material converges in the middle into a narrow portion and diverges at both ends into a wide portion. The shape of the material is similar to that of a P electron cloud. The material with the special morphology has excellent structural stability and excellent electrochemical performance; for example, excellent rate capability and cycling stability.
The primary structure of the ternary cathode active material is at least one of nanorods, nanowires, nanosheets and nanospheres of the ternary cathode active material.
Preferably, the ternary positive electrode active material is a nickel-cobalt-manganese ternary active material.
Further preferably, the ternary positive electrode active material is a lithium-rich manganese-based ternary active material, and the preferred chemical formula is xLi2MnO3·(1-x)LiMO2(M＝Ni、Co、Mn；1>X>0) (ii) a Further preferred is Li1.2Mn0.54Ni0.13Co0.13O2。
The invention also provides a preparation method of the precursor of the ternary cathode active material with the nano-micro hierarchical structure, which comprises the steps of carrying out solvent heat treatment on a mixed solution of a precursor metal source containing the ternary cathode active material, N-dimethylformamide and glycerol, and separating to obtain the precursor of the ternary cathode active material with the dumbbell-shaped appearance;
the volume ratio of the N, N-dimethylformamide to the glycerol is 3-5: 1.
The invention innovatively discovers that the precursor with the dumbbell-shaped appearance can be prepared by carrying out the solvothermal reaction in the combined system of DMF and glycerol with the specific ratio under the ternary metal source.
In the invention, the ternary metal source system is one of the keys for successfully obtaining the precursor with the dumbbell shape.
Preferably, the precursor metal source comprises a metal source capable of providing nickel, cobalt and manganese; preferably at least one of the sulfates, chlorides, formates, acetates, nitrates of said nickel, cobalt and manganese.
Preferably, the precursor metal sources include nickel sources, cobalt sources, and manganese sources.
In the invention, the proportion of nickel, cobalt and manganese can be adjusted according to the use requirement of the lithium ion battery anode material. For example, the molar ratio of nickel, cobalt, and manganese in the mixed solution is formulated in a stoichiometric ratio of the positive electrode active material, for example, the molar ratio of nickel, cobalt, and manganese is 4: 1:1, preparing materials.
In the invention, the combination system of DMF and glycerol is another key for successfully constructing the dumbbell shape. Researches show that DMF provided by the invention is used as a metal precipitator and a solvent, and the precursor with dumbbell shape can be prepared by the DMF and glycerol in required proportion.
Preferably, the volume ratio of DMF to glycerol is 3.5-4.5: 1; further preferably 4: 1. The research of the invention finds that the solution system with the optimal proportion can unexpectedly obtain the dumbbell-shaped material assembled by the precursor nanowires, and the material is beneficial to obtaining the positive electrode active material with higher performance.
It has also been found that further control of the solvothermal temperature helps to further facilitate obtaining the precursor.
Preferably, the solvothermal temperature is greater than or equal to 140 ℃; preferably 140 to 200 ℃.
The solvothermal time is, for example, from 6h to 36 h.
The invention also provides a preparation method of the ternary cathode active material with the nano-micro hierarchical structure, and the precursor with the dumbbell shape is prepared by utilizing the precursor preparation method; and then lithiating and sintering to obtain the lithium iron phosphate.
According to the technical scheme, under the ternary metal source system and the special proportion of the solvent system, the precursor in the dumbbell shape is prepared through solvothermal preparation, and the precursor is further obtained through lithiation and sintering.
In the invention, the precursor of the ternary positive electrode active material is pre-calcined and then lithiated and sintered;
preferably, the pre-forging temperature is 400-600 ℃;
the pre-calcination time is preferably 4-8 h;
the atmosphere in the pre-calcination stage is air or oxygen.
Preferably, the lithium salt added in the lithiation sintering process is at least one of lithium carbonate or lithium hydroxide; the Li excess coefficient is preferably 1.0 to 1.05 in terms of Li/M.
The lithiation sintering comprises one-stage sintering at the temperature of 400-600 ℃ and two-stage sintering at the temperature of 600-1000 ℃; wherein the sintering time for one period is 2-6 h; the time of the second sintering is 8-24 h.
The invention relates to a preparation method of a ternary positive electrode active material with a preferable nano-micro hierarchical structure, which comprises the following steps:
(1) dissolving metal manganese salt, nickel salt and cobalt salt into N, N-dimethylformamide to form a solution A;
(2) adding glycerol to solution a to form solution B; the ratio of the N, N-dimethylformamide to the glycerol is 4-5: 1;
(3) fully stirring the solution B, and synthesizing a precursor by adopting a solvothermal method;
(4) fully washing, drying and pre-calcining the prepared precursor to obtain transition metal oxide;
(5) and lithiating and sintering the transition metal oxide to prepare the lithium-rich manganese-based positive electrode material.
The preparation method takes a manganese source, a nickel source and a cobalt source as metal sources, does not have an external reinforcement precipitator, takes N, N-dimethylformamide/organic solvent as a mixed solvent system, takes lithium carbonate or lithium hydroxide as a lithium source, and adopts a solvothermal-high temperature sintering method to prepare the lithium-rich manganese-based anode material with the dumbbell-shaped nano-micro hierarchical structure.
Furthermore, the ternary positive electrode active material is a lithium-rich manganese-based positive electrode material with a chemical formula of Li1.2Mn0.54Ni0.13Co0.13O2. The elements of nickel, cobalt and manganese in the solution A are metered according to the chemical formula (a reasonable range of error is allowed).
Further, in the step (3), the solvothermal method adopts a traditional solvothermal method, wherein the solvothermal temperature is 140-200 ℃, and the solvothermal time is 6-36 h.
Further, in the step (4), the pre-calcination temperature is 400-.
Further, in the step (5), the lithium sintering lithium salt is lithium carbonate or lithium hydroxide, and the Li excess coefficient is 1.0 to 1.05(M means the total molar amount of nickel, cobalt, and manganese).
Further, in the step (5), the lithiation sintering adopts a two-step sintering method, wherein the pre-sintering temperature is 400-.
The invention also discloses an application of the ternary cathode active material with the nano-micro hierarchical structure, which comprises the following steps: the obtained product can be used for preparing the anode active material of the lithium ion battery.
Preferably, the application is used for preparing a positive electrode material of a lithium ion battery.
Further preferred use is for the preparation of a positive electrode for a lithium ion battery.
A further preferred use is in the preparation of lithium ion batteries.
The invention also comprises the anode material of the lithium ion battery, which comprises the ternary anode active material with the nano-micro hierarchical structure, a conductive agent and a binder. The conductive agent and the binder can be made of materials known in the industry, the dosage can be adjusted based on the existing theory, and the preparation method can also be the existing method.
The invention also provides a lithium ion battery anode which comprises a current collector and the anode material compounded on the surface of the current collector.
In the invention, the anode can be prepared by adopting the existing method and utilizing the anode material.
For example, the ternary positive electrode active material with the nano-micro structure, the conductive agent and the binder are slurried by a solvent to prepare positive electrode slurry, the positive electrode slurry is coated on the surface of a positive electrode current collector, and the positive electrode is obtained by curing and compounding the positive electrode slurry on the surface of the positive electrode current collector.
As a general technical concept, the invention also provides a lithium ion battery comprising the ternary cathode active material with the nano-micro hierarchical structure.
The preferable lithium ion battery comprises a positive electrode material compounded with the ternary positive electrode active material with the nano-micro hierarchical structure.
A more preferred lithium ion battery is loaded with a positive electrode compounded with the positive electrode material.
Compared with the prior art, the invention has the following advantages:
1. the invention provides a ternary active material with a special dumbbell-shaped nano-micro structure formed by self-assembly radiation of nanorods, wherein a primary nanorod unit of the material has good kinetic advantages, the diffusion path and the transfer channel of lithium ions in the material are shortened, and a secondary dumbbell-shaped micron unit ensures the volume energy density and the structural stability of the material.
2. By utilizing the dual-function effect of N, N-dimethylformamide and glycerol in the solvent thermal process and without adding an external reinforcement precipitator, the uniform precipitation and distribution of elements in the preparation process of the cathode material are ensured, and a precursor with a special dumbbell shape can be constructed; and further carrying out lithiation roasting to obtain the dumbbell-shaped ternary active material.
The invention has simple process and obvious and reliable performance improvement, and is suitable for large-scale production.
Drawings
Fig. 1 is an SEM image of the lithium-rich manganese-based positive electrode material precursor prepared in example 1.
Fig. 2 and 3 are SEM images of the lithium-rich manganese-based positive electrode material (positive electrode active material) prepared in example 1; wherein, fig. 2 is a partially enlarged view; fig. 3 is a view of a large window.
Fig. 4 is an EDX diagram of the lithium-rich manganese-based positive electrode material (positive electrode active material) prepared in example 1.
Fig. 5 is an XRD pattern of the lithium-rich manganese-based positive electrode material (positive electrode active material) prepared in example 1.
Fig. 6 is a graph showing the electrical properties of the lithium-rich manganese-based positive electrode material (positive electrode active material) prepared in example 1.
Fig. 7 is an SEM image of the precursor and the positive electrode material (positive electrode active material) prepared in example 2.
Fig. 8 is an SEM image of the precursor and the positive electrode material (positive electrode active material) prepared in example 3.
Fig. 9 is an SEM image of the precursor and the positive electrode material (positive electrode active material) prepared in example 4.
Fig. 10 is an SEM image of the precursor and the positive electrode material (positive electrode active material) prepared in example 5.
Fig. 11 is an SEM image of the precursor and the positive electrode material (positive electrode active material) prepared in comparative example 1.
Fig. 12 is an SEM image of the precursor and the positive electrode material (positive electrode active material) prepared in comparative example 2.
Fig. 13 is an SEM image of the precursor and the positive electrode material (positive electrode active material) prepared in comparative example 3.
Fig. 14 is an SEM image of the precursor and the positive electrode material (positive electrode active material) prepared in comparative example 5.
Fig. 15 is an SEM image of the precursor and the positive electrode material (positive electrode active material) prepared in comparative example 6.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The embodiment shows a preparation method of a lithium-rich manganese-based cathode material with a dumbbell-shaped nano-micro hierarchical structure, which comprises the following specific steps:
(1) mixing the components in a molar mass ratio of 4: 1: dissolving manganese acetate, nickel acetate and cobalt acetate of 1 into N, N-dimethylformamide, and fully stirring to form a transparent solution A;
(2) mixing N, N-dimethylformamide in the step (1) in a volume ratio of 4: adding glycerol of 1 into the solution A, and fully stirring to form a transparent solution B (the volume ratio of DMF/glycerol is 4: 1);
(3) fully stirring the solution B, and synthesizing a precursor with a dumbbell-shaped appearance by adopting a solvothermal method (reaction in a closed container), wherein the solvothermal temperature is 160 ℃, and the solvothermal time is 20 hours;
(4) fully washing, drying, pre-calcining and lithiating and sintering the prepared precursor to prepare a transition metal oxide, wherein the pre-calcining temperature is 550 ℃, the pre-calcining time is 4 hours, the heating rate is 5 ℃/min, and the pre-calcining atmosphere is air;
(5) lithiating and sintering a transition metal oxide by adopting a two-stage sintering method, wherein the pre-sintering temperature is 550 ℃, the pre-sintering time is 4h, the high-temperature sintering temperature is 850 ℃, the sintering temperature is 12h, the heating rate is 3 ℃/min, and the sintering atmosphere is oxygen atmosphere to obtain the positive electrode composite material ((Li)1.2Mn0.54Ni0.13Co0.13O2))。
Example 2
Compared with the example 1, the difference is only that the volume ratio of the N, N-dimethylformamide to the glycerol is 5: 1. the other steps and parameters were the same as in example 1. SEM of the precursor obtained in step (3) and the positive electrode active material sintered in the subsequent step (5) is shown in fig. 7.
Example 3
Compared with the example 1, the difference is only that the volume ratio of the N, N-dimethylformamide to the glycerol is 3: 1. the other steps and parameters were the same as in example 1. SEM of the precursor obtained in step (3) and the positive electrode active material sintered in the subsequent step (5) is shown in fig. 8.
Example 4
The difference compared to example 1 is only that the solvothermal temperatures are in each case 140 ℃. The other steps and parameters were the same as in example 1. SEM of the precursor obtained in step (3) and the positive electrode active material sintered in the subsequent step (5) is shown in fig. 9.
Example 5
The difference compared with example 1 is only that the solvothermal temperatures are 200 ℃. The other steps and parameters were the same as in example 1. SEM of the precursor obtained in step (3) and the positive electrode active material sintered in the subsequent step (5) is shown in fig. 10.
Comparative example 1
Compared with example 1, the difference is that solvothermal is carried out using a single DMF system, specifically:
(1) mixing the components in a molar mass ratio of 4: 1: dissolving manganese acetate, nickel acetate and cobalt acetate of 1 into N, N-dimethylformamide, and fully stirring to form a transparent solution A;
(2) fully stirring the solution A, and synthesizing a precursor by adopting a solvothermal method, wherein the solvothermal temperature is 160 ℃, and the time is 10 hours;
(3) fully washing, drying, pre-calcining and lithiating and sintering the prepared precursor to prepare a transition metal oxide, wherein the pre-calcining temperature is 450 ℃, the pre-calcining time is 4 hours, the heating rate is 5 ℃/min, and the pre-calcining atmosphere is air;
(4) lithiating and sintering the transition metal oxide by adopting a two-stage sintering method, wherein the pre-sintering temperature is 450 ℃, the pre-sintering time is 4 hours, the high-temperature sintering temperature is 800 ℃, the sintering temperature is 10 hours, the heating rate is 3 ℃/min, and the sintering atmosphere is oxygen atmosphere.
In the process of solvothermal synthesis of the precursor, only N, N-dimethylformamide is used as a solvent system, and no organic solvent is added, so that the effect of the precipitant in the solvothermal process of the N, N-dimethylformamide is verified. The precursor and the positive electrode material prepared are shown in fig. 11.
Comparative example 2
The solvothermal system is DMF + ethanol, and specifically comprises the following components:
(1) mixing the components in a molar mass ratio of 4: 1: dissolving manganese chloride, nickel chloride and cobalt chloride of the step 1 into N, N-dimethylformamide, and fully stirring to form a transparent solution A;
(2) mixing N, N-dimethylformamide in the step (1) in a volume ratio of 3: adding ethanol of 1 into the solution A, and fully stirring to form a transparent solution B;
(3) fully stirring the solution B, and synthesizing a precursor by adopting a solvothermal method, wherein the solvothermal temperature is 160 ℃, and the time is 20 hours;
(4) fully washing, drying, pre-calcining and lithiating and sintering the prepared precursor to prepare a transition metal oxide, wherein the pre-calcining temperature is 550 ℃, the pre-calcining time is 4 hours, the heating rate is 5 ℃/min, and the pre-calcining atmosphere is air;
(5) lithiating and sintering the transition metal oxide by adopting a two-stage sintering method, wherein the pre-sintering temperature is 550 ℃, the pre-sintering time is 2 hours, the high-temperature sintering temperature is 900 ℃, the sintering temperature is 12 hours, the heating rate is 3 ℃/min, and the sintering atmosphere is oxygen atmosphere. SEM images of the precursor and the cathode material are shown in fig. 12.
Comparative example 3
The solvothermal system is DMF + ethylene glycol, and specifically comprises:
(1) mixing the components in a molar mass ratio of 4: 1: dissolving manganese sulfate, nickel sulfate and cobalt sulfate of 1 into N, N-dimethylformamide, and fully stirring to form a transparent solution A;
(2) mixing N, N-dimethylformamide in the step (1) in a volume ratio of 1: adding ethylene glycol 1 into the solution A, and fully stirring to form a transparent solution B;
(3) fully stirring the solution B, and synthesizing a precursor by adopting a solvothermal method, wherein the solvothermal temperature is 160 ℃, and the time is 20 hours;
(4) fully washing, drying, pre-calcining and lithiating and sintering the prepared precursor to prepare a transition metal oxide, wherein the pre-calcining temperature is 550 ℃, the pre-calcining time is 4 hours, the heating rate is 3 ℃/min, and the pre-calcining atmosphere is air;
(5) lithiating and sintering the transition metal oxide by adopting a two-stage sintering method, wherein the pre-sintering temperature is 600 ℃, the pre-sintering time is 6 hours, the high-temperature sintering temperature is 950 ℃, the sintering temperature is 16 hours, the heating rate is 3 ℃/min, and the sintering atmosphere is air atmosphere. SEM images of the precursor and the cathode material are shown in fig. 13.
Comparative example 4
The only difference compared to example 1 is that the solvothermal system is glycerol only. This comparative example failed to prepare because the metal salt was difficult to dissolve in the glycerol system.
Comparative example 5:
the only difference compared to example 1 is that the solvothermal system is a DMF/glycerol ═ 1:1 system. SEM images of the precursor and the cathode material are shown in fig. 14.
Comparative example 6:
the only difference compared to example 1 is that the solvothermal system is DMF/glycerol ═ 10: 1. SEM images of the precursor and the cathode material are shown in fig. 15.
Comparative example 7:
the only difference compared to example 1 is that the solvothermal temperature is 120 ℃. At this temperature, no precipitate was produced, and the comparative example failed.
And (3) electrochemical performance testing:
positive electrode active material (Li) synthesized in each example and comparative example1.2Mn0.54Ni0.13Co0.13O2) The sample is a positive electrode material, acetylene black is a conductive agent, and polyvinylidene fluoride (PVDF) is a binder, and the materials are fully mixed and ground according to the mass ratio of 8:1: 1. Then, N-methyl-2-pyrrolidone (NMP) was added dropwise to dissolve the resulting solution sufficiently. And finally, coating the slurry on an aluminum foil, and drying to obtain the positive plate. A metal lithium sheet is used as a negative electrode, 1 mol.L < -1 > LiPF 6 dissolved in Ethylene Carbonate (EC), dimethyl carbonate (DMC) and Ethyl Methyl Carbonate (EMC) (volume ratio of 1:1:1) solution is used as electrolyte, a polypropylene microporous membrane (Celgard 2400) is used as a diaphragm, a CR2025 button cell is assembled in a glove box filled with argon, and the cell is sealed by a sealing machine. A battery testing system with the model of LAND-CT2001A is adopted to carry out the rate capability test of the battery, and the charging and discharging voltage interval is 2.0-4.8V. TABLE 1 Li synthesized in comparative example 1 and related comparative examples1.2Mn0.54Ni0.13Co0.13O2The initial specific capacity of the lithium-rich manganese-based positive electrode material under the current density of 0.2C and the specific capacity after 200 circles. FIG. 6 shows Li synthesized in example 11.2Mn0.54Ni0.13Co0.13O2And (3) a rate performance graph of the lithium-rich manganese-based positive electrode material.
TABLE 1
Figure BDA0002408569110000101
As can be seen from Table 1, Li synthesized by the present invention1.2Mn0.54Ni0.13Co0.13O2The lithium-rich manganese-based positive electrode material has excellent electrochemical performance, particularly the best lithium-rich manganese-based positive electrode material in the embodiment 1 can reach 278.8mAh g after 200 circles under the current density of 0.2C-1The lithium-rich manganese-based cathode material has excellent cycle performance and excellent rate performance as shown in FIG. 6, and solves the problems of unstable cycle performance and poor rate performance of the commercial lithium-rich manganese-based cathode material.
And (3) morphology characterization:
FIGS. 1-4 show Li of different morphologies prepared by the examples1.2Mn0.54Ni0.13Co0.13O2The SEM pictures of the precursor and the lithium-rich manganese-based cathode material show that the precursor can be generated in a pure N, N-dimethylformamide system in a solvent thermal process without adding a solid precipitator. The lithium-rich manganese-based cathode material with a dumbbell-shaped nano-micro-scale structure can be obtained by solvothermal reaction in the special DMF-glycerol mixed solvent system, and the distribution of elements of the material synthesized without the solid precipitator is uniform as shown by an EDX picture of a lens in figure 4.
And (3) crystal form analysis:
FIG. 5 shows Li prepared in example 11.2Mn0.54Ni0.13Co0.13O2The XRD pattern of the lithium-rich manganese-based anode material is analyzed to be a typical layered lithium-rich structure, and the crystal form is complete without any impurity phase.
While only a few embodiments of the present invention have been described in detail above, those skilled in the art will readily appreciate that many other modifications and adaptations of the present invention are possible within the spirit of the present invention and are contemplated by those skilled in the art
All changes and modifications within the spirit of the invention should be included within the scope of the invention.

Claims (10)

1. The ternary positive electrode active material with the nano-micro hierarchical structure is characterized by having a dumbbell-shaped appearance.
2. The ternary positive electrode active material with the nano-micro structure of claim 1, which is a material with a dumbbell-shaped secondary morphology and assembled by a ternary positive electrode active material primary structure;
the primary structure of the ternary cathode active material is at least one of nanorods, nanowires, nanosheets and nanospheres of the ternary cathode active material;
preferably, the ternary positive active material is a nickel-cobalt-manganese ternary active material; the preferred formula is xLi2MnO3·(1-x)LiMO2(M＝Ni、Co、Mn；1>X>0) (ii) a Further preferred is Li1.2Mn0.54Ni0.13Co0.13O2。
3. A preparation method of a precursor of a ternary cathode active material with a nano-micro hierarchical structure is characterized in that a mixed solution containing a precursor metal source of the ternary cathode active material, N-dimethylformamide and glycerol is subjected to solvent heat treatment, and the precursor of the ternary cathode active material with a dumbbell-shaped appearance is obtained through separation;
the volume ratio of the N, N-dimethylformamide to the glycerol is 3-5: 1.
4. The method of claim 3, wherein the precursor metal source comprises a metal source capable of providing nickel, cobalt and manganese; preferably at least one of the sulfates, chlorides, formates, acetates, nitrates of said nickel, cobalt and manganese.
5. The method for preparing the precursor of the ternary positive electrode active material with the nano-micro structure according to claim 3, wherein the solvothermal temperature is 140 ℃ or higher; preferably 140 to 200 ℃.
6. The preparation method of the ternary cathode active material with the nano-micro level structure as claimed in any one of claims 1 to 2 is characterized in that the ternary cathode active material precursor is prepared by the preparation method as claimed in any one of claims 3 to 5, and then lithiation and sintering are carried out to obtain the ternary cathode active material.
7. The method for preparing the ternary cathode active material with the nano-micro structure as claimed in claim 6, wherein the ternary cathode active material precursor is pre-calcined and then lithiated and sintered;
preferably, the pre-forging temperature is 400-600 ℃;
the pre-calcination time is preferably 4-8 h;
the atmosphere in the pre-calcination stage is air or oxygen.
8. The method for preparing ternary positive electrode active material with nano-micro structure as claimed in claim 6, wherein the lithium salt added during lithiation sintering is at least one of lithium carbonate or lithium hydroxide; the Li excess coefficient is preferably 1.0-1.05;
the lithiation sintering comprises one-stage sintering at the temperature of 400-600 ℃ and two-stage sintering at the temperature of 600-1000 ℃; wherein the sintering time for one period is 2-6 h; the time of the second sintering is 8-24 h.
9. The application of the ternary cathode active material with the nano-micro structure in the claim 1 or 2 or the ternary cathode active material with the nano-micro structure prepared by the preparation method in any one of the claims 6 to 8 is characterized in that the ternary cathode active material is used as a cathode active material of a lithium ion battery;
preferably, the method is used for preparing the lithium ion battery cathode material;
further preferably, the method is used for preparing the lithium ion battery anode;
still more preferably, it is used for the preparation of lithium ion batteries.
10. A lithium ion battery, characterized by comprising the ternary cathode active material with a nano-micro structure of claim 1 or 2, or the ternary cathode active material with a nano-micro structure prepared by the preparation method of any one of claims 6 to 8;
preferably, the positive electrode material compounded with the ternary positive electrode active material with the nano-micro hierarchical structure is contained;
further preferably, the positive electrode comprises the ternary positive electrode active material with the nano-micro hierarchical structure.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107959022A (en) * 2017-10-31 2018-04-24 华南理工大学 A kind of solvent-thermal method prepares tertiary cathode material and preparation method thereof
CN109768272A (en) * 2018-12-07 2019-05-17 华南理工大学 A kind of richness lithium tertiary cathode material and its environment-friendly preparation method thereof

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107959022A (en) * 2017-10-31 2018-04-24 华南理工大学 A kind of solvent-thermal method prepares tertiary cathode material and preparation method thereof
CN109768272A (en) * 2018-12-07 2019-05-17 华南理工大学 A kind of richness lithium tertiary cathode material and its environment-friendly preparation method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
WON-HEE RYU等: ""3-D dumbbell-like LiNi1/3Mn1/3Co1/3O2 cathode materials assembled with nano-building blocks for lithium-ion batteries"", 《JOURNAL OF POWER SOURCES》 *

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