Layered manganese-based positive electrode material of sodium-ion battery and preparation method thereof
阅读说明：本技术 一种钠离子电池层状锰基正极材料及其制备方法 (Layered manganese-based positive electrode material of sodium-ion battery and preparation method thereof ) 是由 曹志杰 李丽江 马晓波 于 2020-07-14 设计创作，主要内容包括：本发明公开了一种钠离子电池层状锰基正极材料及其制备方法,所述正极材料的通式为Na<Sub>2/3</Sub>Ni<Sub>1/3</Sub>Mn<Sub>2/3-x</Sub>Ti<Sub>x</Sub>O<Sub>2</Sub>(1/10≤x≤3/10)。本发明所制备的锰基正极材料具有P2相层状结构,表面形貌光滑且尺寸均匀,颗粒大小为1～3μm；材料在2.5～4.4V的宽电压范围内充放电过程中不发生相转变,具有很好的结构稳定性以及在空气中的稳定性,具有优异的倍率性能和循环稳定性。本发明采用溶胶凝胶法和高温煅烧法两步进行合成,制备过程操作简便、烧结温度低、时间短、能耗低。(The invention discloses a layered manganese-based positive electrode material of a sodium-ion battery and a preparation method thereof, wherein the general formula of the positive electrode material is Na 2/3 Ni 1/3 Mn 2/3‑x Ti x O 2 (1/10 ≦ x ≦ 3/10). The manganese-based anode material prepared by the invention has a P2 phase layered structure, the surface appearance is smooth, the size is uniform, and the particle size is 1-3 mu m; the material does not generate phase transition in the charging and discharging process within a wide voltage range of 2.5-4.4V, has good structural stability and stability in air, and has excellent rate capability and cycle stability. Hair brushObviously, the sol-gel method and the high-temperature calcination method are adopted for synthesis, and the preparation process is simple and convenient to operate, low in sintering temperature, short in time and low in energy consumption.)
1. The layered manganese-based positive electrode material of the sodium-ion battery is characterized in that the general formula of the material is Na2/3Ni1/3Mn2/3-xTixO2Wherein x is not less than 1/10 and not more than 3/10.
2. The preparation method of the layered manganese-based positive electrode material of the sodium-ion battery according to claim 1, characterized by comprising the following steps:
(1) weighing sodium nitrate, manganese nitrate, nickel nitrate hexahydrate and tetrabutyl titanate according to a stoichiometric ratio, dissolving in distilled water, and then adding a chelating agent to obtain a mixed solution;
(2) heating the mixed solution in the step (1) and carrying out magnetic stirring treatment to obtain gel;
(3) heating and drying the gel in the step (2) to obtain a solid sample, and then grinding the solid sample into powder;
(4) calcining the powder in the step (3) in an air atmosphere to obtain Na2/3Ni1/3Mn2/3-xTixO2。
3. The method for preparing the layered manganese-based positive electrode material of the sodium-ion battery according to claim 2, wherein the chelating agent in the step (1) is citric acid.
4. The preparation method of the layered manganese-based positive electrode material for the sodium-ion battery according to claim 3, wherein the mass ratio of the citric acid in the step (1) is 40-50%.
5. The preparation method of the layered manganese-based positive electrode material for the sodium-ion battery according to claim 2, wherein the heating temperature in the step (2) is 50-100 ℃.
6. The preparation method of the layered manganese-based positive electrode material for the sodium-ion battery according to claim 2, wherein the drying temperature in the step (3) is 100-200 ℃, and the heat preservation time is 5-10 hours.
7. The preparation method of the layered manganese-based positive electrode material for the sodium-ion battery according to claim 2, wherein the calcination temperature in the step (4) is 400-1000 ℃, the calcination time is 10-20 h, and the heating speed is 5 ℃/min.
8. The application of the layered manganese-based positive electrode material of the sodium-ion battery as defined in claim 1 as a positive electrode material of the sodium-ion battery.
Technical Field
The invention relates to the technical field of electrochemistry, in particular to a layered manganese-based positive electrode material of a sodium-ion battery and a preparation method thereof.
Background
In recent years, China develops rapidly in the field of new energy such as solar energy, wind energy, geothermal energy, tidal energy and the like, but the clean energy has strong randomness, regionality, intermittency and instability, the clean energy and the clean energy are converted into electric energy and directly input into a power grid to bring huge impact to the whole system, and a smart power grid with an efficient energy storage technology is developed, so that the energy utilization efficiency can be improved, the stability of the output power of the power grid can be improved, and the continuous and stable large-scale application of the new energy is realized.
Among a plurality of energy storage technologies, electrochemical energy storage has the advantages of high energy density, high power density, high conversion efficiency, good safety performance and the like, and has wide application prospect in the field of energy storage. At present, lithium ion batteries are applied to the field of small 3C in a large scale, and are gradually developing into the fields of large-scale energy storage such as electric vehicles, artificial intelligence, aerospace and the like. However, the reserve of lithium resources in the crust is relatively deficient, and the distribution of regions is extremely uneven, so that the rapidly growing market of the lithium ion battery inevitably aggravates the consumption of the lithium resources to promote the price of lithium to greatly rise, and the lithium ion battery is difficult to meet the low-cost requirement of large-scale application. The sodium resource reserves are very abundant and widely distributed, and the physical and chemical properties of sodium and lithium are similar, so that the technology of adopting sodium ions to replace lithium ions for energy storage is completely feasible, and in addition to the gradual development of some high-performance electrode materials, the sodium ion battery is expected to gradually replace a lithium ion battery to realize cheap large-scale energy storage.
The positive electrode material is used as an important functional component of the sodium ion battery and is a key for influencing the reversible capacity and the working voltage of the battery, so that the development of the positive electrode material with excellent performance is important for the industrial application of the sodium ion battery. Among various cathode materials, the layered oxide has the advantages of high energy density, simple preparation process, low price, good industrial compatibility and the like, and is receiving wide attention and high attention.
Chinese patent CN108923042A discloses a layered manganese-based positive electrode material of a sodium-ion battery and a preparation method thereof, wherein the general formula of the positive electrode material is NayMn3-xMxO7Wherein M is Ti, V, Cr, Fe, Co, Ni,Mg, Zn, Zr, Nb, Ru, Ir or Cu, wherein x is more than or equal to 0.1 and less than or equal to 2, and y is more than or equal to 0 and less than or equal to 4. The preparation method comprises the following steps: the sodium salt, the manganese carbonate and the metal oxide are uniformly mixed and then tableted, and then calcined at the temperature of 400-1100 ℃ to obtain the layered manganese-based positive electrode material of the sodium-ion battery. The patent uses a solid-phase sintering method, can form a layered oxide having a triclinic crystal structure by controlling reaction conditions, and has a structural characteristic of no phase change over a wide voltage range. The precursor substances of the sample are mutually diffused at high temperature, so that the microscopic discrete particles gradually form a continuous solid layered structure, and the stable sodium-containing triclinic layered oxide material is obtained. At present, no record exists for successfully preparing the layered manganese-based positive electrode material of the sodium-ion battery with the characteristic of no phase change structure in a wide voltage range by adopting a liquid phase method.
Disclosure of Invention
The invention aims to provide a layered manganese-based positive electrode material of a sodium-ion battery with excellent electrochemical performance and a preparation method of the material.
In order to achieve the purpose, the invention provides the following scheme:
the invention provides a layered manganese-based positive electrode material of a sodium ion battery, which has a general formula of Na2/3Ni1/3Mn2/3-xTixO2Wherein x is not less than 1/10 and not more than 2/10, the layered manganese-based positive electrode material of the sodium-ion battery is a P2 phase layered material, the surface appearance is smooth, the size is uniform, and the particle size is 1-3 mu m.
The invention also provides a preparation method of the layered manganese-based positive electrode material of the sodium-ion battery, which comprises the following steps:
(1) weighing raw materials according to a stoichiometric ratio, dissolving the raw materials in distilled water, and then adding a chelating agent to obtain a mixed solution;
(2) heating the mixed solution in the step (1) and carrying out magnetic stirring treatment to obtain gel;
(3) heating and drying the gel in the step (2) to obtain a solid sample, and then grinding the solid sample into powder;
(4) calcining the powder in the step (3) in an air atmosphere to obtain Na2/3Ni1/3Mn2/3-xTixO2。
As a further improvement of the invention, the chelating agent in the step (1) is citric acid.
As a further improvement of the invention, the mass ratio of the citric acid in the step (1) is 40-50%.
As a further improvement of the invention, the heating temperature in the step (2) is 50-100 ℃.
As a further improvement of the invention, the drying temperature in the step (3) is 100-200 ℃, and the heat preservation time is 5-10 h.
As a further improvement of the invention, the calcination temperature in the step (4) is 400-1000 ℃, the calcination time is 10-20 h, and the heating speed is 5 ℃/min.
The invention also provides application of the layered manganese-based positive electrode material of the sodium-ion battery as a positive electrode material of the sodium-ion battery.
The invention discloses the following technical effects:
(1) the invention provides a P2-based layered Na2/3Ni1/3Mn2/3O2By doping and introducing Ti element, the material has the structural characteristic of no phase change in a wide voltage range, so that the material has smaller volume effect in the charge-discharge process, and Jahn-Teller phase change can be effectively inhibited, thereby improving the structural stability and the electrochemical performance of the material.
(2) The positive electrode material of the sodium-ion battery prepared by the invention has the advantages of high specific capacity, high discharge voltage, stable circulation, good safety performance and the like, and can meet the requirement of large-scale energy storage application of the sodium-ion battery.
(3) The preparation method is carried out by adopting a sol-gel method and a high-temperature calcination method, the method is simple to operate, the sintering temperature is low, the preparation time is short, the energy consumption is low, the practicability is high, the prepared material is smooth in surface appearance and uniform in size, and the industrial cost is favorably reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
FIG. 1 shows Na as a product prepared in example 22/3Ni1/3Mn17/30Ti1/10O2XRD pattern of (a).
FIG. 2 shows Na as a product prepared in example 62/3Ni1/3Mn11/30Ti3/10O2XRD pattern of (a).
FIG. 3 shows Na as the product of example 22/3Ni1/3Mn17/30Ti1/10O2SEM image of (d).
FIG. 4 shows Na as a product obtained in example 62/3Ni1/3Mn11/30Ti3/10O2A TEM image of (a).
FIG. 5 shows Na as the product of example 62/3Ni1/3Mn11/30Ti3/10O2In-situ XRD pattern during charging and discharging process.
FIG. 6 shows Na as the product of example 22/3Ni1/3Mn17/30Ti1/10O2The first three cyclic voltammograms of (a).
FIG. 7 shows Na as the product of example 62/3Ni1/3Mn11/30Ti3/10O2The first three cyclic voltammograms of (a).
FIG. 8 shows Na as a product obtained in example 22/3Ni1/3Mn17/30Ti1/10O2The current of the first, third and fifth cyclic voltammogram of (1) is 0.1C.
FIG. 9 shows Na as a product obtained in example 62/3Ni1/3Mn11/30Ti3/10O2The current of the first, third and fifth cyclic voltammogram of (1) is 0.1C.
FIG. 10 shows Na as the product of example 22/3Ni1/3Mn17/30Ti1/10O2And product Na from example 62/ 3Ni1/3Mn11/30Ti3/10O2The current was 0.1C.
Detailed Description
Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.
It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.
It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The specification and examples are exemplary only.
As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.