阅读说明：本技术 一种微米球形铌酸钛及其制备方法和应用 (Micron spherical titanium niobate and preparation method and application thereof ) 是由 张校刚 蒋江民 窦辉 于 2019-11-04 设计创作，主要内容包括：本发明涉及电极材料技术领域,尤其涉及一种微米球形TiNb<Sub>24</Sub>O<Sub>62</Sub>及其制备方法和应用。本发明提供的制备方法,包括以下步骤：将钛源、铌源和分散剂混合,依次进行喷雾热解和煅烧,得到所述微米球形TiNb<Sub>24</Sub>O<Sub>62</Sub>。根据实施例的记载,以所述微米球形TiNb<Sub>24</Sub>O<Sub>62</Sub>作为锂离子电池的负极材料时,在0.1A g<Sup>-1</Sup>电流密度下可逆比容量可达200～260mAh·g<Sup>-1</Sup>,且在5A g<Sup>-1</Sup>的大电流密度下依然能保留100～155mAh·g<Sup>-1</Sup>的可逆比容量,并在1A·g<Sup>-1</Sup>电流密度下循环500次后,其比容量的保持率能达到80％～92％,具有优异的倍率性能和循环稳定性能。(The invention relates to the technical field of electrode materials, in particular to a micron spherical TiNb 24 O 62 And a preparation method and application thereof. The preparation method provided by the invention comprises the following steps: mixing a titanium source, a niobium source and a dispersing agent, and sequentially carrying out spray pyrolysis and calcination to obtain the micron spherical TiNb 24 O 62 . According to the description of the embodiment, the micron spherical TiNb is adopted 24 O 62 When the material is used as a negative electrode material of a lithium ion battery, the value is 0.1A g ‑1 The reversible specific capacity under the current density can reach 200-260 mAh.g ‑1 And at 5A g ‑1 Can still retain 100-155 mAh.g under the high current density ‑1 And a reversible specific capacity of 1 A.g ‑1 After the current density is cycled for 500 times, the specific capacity retention rate can reach 80 to 92 percent,has excellent rate performance and cycle stability.)

1. Micron spherical TiNb ₂₄O ₆₂The preparation method is characterized by comprising the following steps:

mixing a titanium source, a niobium source and a dispersing agent, and sequentially carrying out spray pyrolysis and calcination to obtain the micron spherical TiNb ₂₄O ₆₂。

2. The method of claim 1, wherein the molar ratio of titanium in the titanium source to niobium in the niobium source is 1: 24.

3. The method of claim 2, wherein the titanium source is one or more of tetrabutyl titanate, titanium tetrachloride, isopropyl titanate, and titanium isopropoxide.

4. The method of claim 2, wherein the niobium source is niobium pentachloride and/or niobium ethoxide.

5. The method according to claim 1, wherein the dispersant is a mixture of an acid solution and an alcohol;

the acid solution is one or more of acetic acid, carbonic acid solution and hypochlorous acid solution;

the alcohol substance is ethanol and/or methanol.

6. The method of claim 1, wherein the carrier gas for spray pyrolysis is nitrogen or argon;

the flow rate of the carrier gas is 100-500 sccm.

7. The method according to claim 1 or 6, wherein the temperature of the spray pyrolysis is 300 to 600 ℃.

8. The preparation method according to claim 1, wherein the calcination temperature is 600 to 1000 ℃, and the calcination time is 3 to 6 hours;

the calcination is carried out in a nitrogen or argon atmosphere.

9. Micron spherical TiNb prepared by the preparation method of any one of claims 1 to 8 ₂₄O ₆₂Characterized in that the micron spherical TiNb ₂₄O ₆₂The diameter of (2) is 1 to 2 μm.

10. The micro-sphere TiNb of claim 9 ₂₄O ₆₂Application in electrode materials.

Technical Field

The invention relates to the technical field of electrode materials, in particular to micron spherical titanium niobate and a preparation method and application thereof.

Background

In order to meet the development requirements of the new era, the development and utilization of new energy have become extremely important and urgent research subjects of human beings, wherein the rapid development of the fields of pure electric vehicles, portable electronic devices and the like puts more and more severe requirements on energy storage devices of the pure electric vehicles, the portable electronic devices and the like. The lithium ion battery is generally regarded by people due to excellent performance, has the advantages of high energy density, high working voltage, long cycle life, small self-discharge and the like, and has been applied on a large scale.

Currently, graphite and lithium titanate are generally used as negative electrode materials of lithium ion batteries. The graphite has a molecular weight of 372mA g ^-1The lithium ion battery has stable theoretical specific capacity and electrochemical performance, but has low first coulombic efficiency, poor rate capability, too low charge-discharge platform and safety problem of generation of metal lithium dendrite. Li ₄Ti ₅O ₁₂The material is a zero-deformation material, has the advantages of long service life, high safety, quick charging, good cycle performance and the like, but has relatively low theoretical specific capacity (175 mA.h.g) ^-1) And the defects of low electronic conductivity, flatulence and the like also exist. Therefore, the design and development of a novel lithium ion battery anode material are very significant and necessary.

TiNb ₂₄O ₆₂Is a novel lithium ion battery cathode material, belongs to a Wadsley-Roth shear phase structure, and has high theoretical specific capacity (402 mA.h.g) ^-1) And excellent safety and cycle stability, have recently received attention from researchers. Currently prepared TiNb ₂₄O ₆₂The material method mainly includes a high-temperature solid phase method, a solvothermal method and the like. Grey et al (Structural stability from crystalline shear in TiO) ₂–Nb ₂O ₅phases:cationordering and lithiation behavior of TiNb ₂₄O ₆₂Inorganic chemistry, 56(2017)4002-4010) discloses the solid phase synthesis of TiNb using high temperatures ₂₄O ₆₂The required temperature is up to 1350 ℃, and the reaction time is 96 h. The product obtained by the method has the particle size of more than 10 mu m, the electrochemical performance is not ideal, and the production energy consumption is large due to long-time high-temperature calcination. Lee et al (how-graphene-wrapped porous TiNb) ₂₄O ₆₂microparticles as high-performance intercalation pseudocapacitive anode materials for lithium-ioncapacitors，NPG Asia Materials,10(2018)406) discloses a solvothermal method for synthesizing TiNb ₂₄O ₆₂The method can regulate and control the structure and the appearance of the material, but is not suitable for industrial large-scale production. Shu et al (Deepiperspectives in kinetics and structural evaluation of nitro-stressed TiNb) ₂₄O ₆₂Nanowires as high-performance lithium conjugate, Nano Energy,54(2018)227- ₂₄O ₆₂The method prepares TiNb with a one-dimensional structure ₂₄O ₆₂But also difficult to realize industrial large-scale production and application.

Therefore, the TiNb with simple process, low energy consumption, high product purity, good crystallinity and excellent electrochemical performance is provided ₂₄O ₆₂The preparation method of the material is always a technical problem to be solved in the field.

Disclosure of Invention

In order to solve the technical problem, the invention provides a micron spherical TiNb ₂₄O ₆₂The preparation method provided by the invention has the advantages of simple process and low energy consumption, and the prepared micron spherical TiNb is ₂₄O ₆₂The product has high purity, good crystallinity and excellent electrochemical performance.

In order to achieve the above purpose, the invention provides the following specific technical scheme:

the invention provides a micron spherical TiNb ₂₄O ₆₂The preparation method comprises the following steps:

mixing a titanium source, a niobium source and a dispersing agent, and sequentially carrying out spray pyrolysis and calcination to obtain the micron spherical TiNb ₂₄O ₆₂。

Preferably, the molar ratio of titanium in the titanium source to niobium in the niobium source is 1: 24.

Preferably, the titanium source is one or more of tetrabutyl titanate, titanium tetrachloride, isopropyl titanate and titanium isopropoxide.

Preferably, the niobium source is niobium pentachloride and/or niobium ethoxide.

Preferably, the dispersant is a mixed solution of an acid solution and an alcohol substance;

the acid solution is one or more of acetic acid, carbonic acid solution and hypochlorous acid solution;

the alcohol substance is ethanol and/or methanol.

Preferably, the carrier gas for spray pyrolysis is nitrogen or argon;

the flow rate of the carrier gas is 100-500 sccm.

Preferably, the temperature of the spray pyrolysis is 300-600 ℃.

Preferably, the calcining temperature is 600-1000 ℃, and the calcining time is 3-6 h;

the calcination is carried out in a nitrogen or argon atmosphere.

The invention also provides the micron spherical TiNb prepared by the preparation method of the technical scheme ₂₄O ₆₂The micron spherical TiNb ₂₄O ₆₂The diameter of (2) is 1 to 2 μm.

The invention also provides the micron spherical TiNb in the technical scheme ₂₄O ₆₂Application in electrode materials.

The invention provides a micron spherical TiNb ₂₄O ₆₂The preparation method comprises the following steps: mixing a titanium source, a niobium source and a dispersing agent, and sequentially carrying out spray pyrolysis and calcination to obtain the micron spherical TiNb ₂₄O ₆₂. The preparation method provided by the invention is simple, low in energy consumption and suitable for industrial production. Prepared TiNb ₂₄O ₆₂The product has high uniformity, high purity, high tap density, good crystallization performance and excellent electrochemical performance. According to the description of the embodiment, the micron spherical TiNb prepared by the invention ₂₄O ₆₂Has a diameter of 1 to 2 μm, and is made of the micron spherical TiNb ₂₄O ₆₂When the material is used as a negative electrode material of a lithium ion battery, the concentration is 0.1 A.g ^-1The reversible specific capacity under the current density can reach 200-260 mA.h.g ^-1And is in the range of 5 A.g ^-1Can still retain 100-155 mAh.g under the high current density ^-1And a reversible specific capacity of 1 A.g ^-1Circulating at current density for 500 timesThe retention rate of the specific capacity of the composite material can reach 80% -92%, and the composite material has excellent rate capability and cycling stability.

Drawings

FIG. 1 is a diagram of micron spherical TiNb prepared in example 1 ₂₄O ₆₂SEM picture of (1);

FIG. 2 is a diagram of the micron spherical TiNb prepared in example 1 ₂₄O ₆₂XRD pattern of (a);

FIG. 3 is a diagram of micron spherical TiNb prepared in example 1 ₂₄O ₆₂A graph of rate performance at different current densities;

FIG. 4 is a diagram of micron spherical TiNb prepared in example 1 ₂₄O ₆₂At 1 A.g ^-1Cycling performance plot at current density.

Detailed Description

The invention provides a micron spherical TiNb ₂₄O ₆₂The preparation method comprises the following steps:

mixing a titanium source, a niobium source and a dispersing agent, and sequentially carrying out spray pyrolysis and calcination to obtain the micron spherical TiNb ₂₄O ₆₂。

In the present invention, all the raw material components are commercially available products well known to those skilled in the art unless otherwise specified.

In the present invention, the titanium source is preferably one or more of tetrabutyl titanate, titanium tetrachloride, isopropyl titanate, and titanium isopropoxide; when the titanium sources are more than two of the specific choices, the proportion of the specific substances is not limited in any way, and the specific substances can be mixed according to any proportion.

In the present invention, the niobium source is preferably niobium pentachloride and/or niobium ethoxide; when the niobium source is niobium pentachloride and niobium ethoxide, the specific material proportion is not limited in any way, and the niobium source can be mixed according to any proportion.

In the invention, the dispersant is preferably a mixed solution of an acid solution and an alcohol substance; the mass ratio of the acid liquid to the alcohol substances is preferably (5-10): 1, more preferably (5-8): 1; the acid solution is preferably one or more of acetic acid, carbonic acid solution and hypochlorous acid solution, and more preferably acetic acid; the concentration of the carbonic acid solution and the hypochlorous acid solution is not particularly limited in the present invention, and may be those known to those skilled in the art. The alcohol substance is preferably ethanol and/or methanol, and when the alcohol substance is ethanol and methanol, the volume ratio of the ethanol to the methanol is preferably (5-10): 1, more preferably (6-8): 1.

in the present invention, the molar ratio of titanium in the titanium source and niobium in the niobium source is preferably 1: 24; the volume ratio of the niobium content in the niobium source to the dispersant is preferably (0.015 to 0.03) mol: (200 to 210) mL, more preferably (0.02 to 0.025) mol:204mL, and most preferably 0.02mol:204 mL.

In the present invention, the mixing is preferably: the niobium source and the dispersing agent are mixed uniformly and then mixed with the titanium source. When the titanium source is in a liquid state, the mixing manner with the titanium source is preferably dropwise, and the dropwise addition is not particularly limited in the present invention.

In the invention, the carrier gas for spray pyrolysis is preferably nitrogen or argon, and the flow rate of the carrier gas is preferably 100-500 sccm, more preferably 200-300 sccm; the temperature of the spray pyrolysis is preferably 300-600 ℃, and more preferably 400-500 ℃.

In the invention, the calcination is preferably carried out in a nitrogen or argon atmosphere, and the calcination temperature is preferably 600-1000 ℃, more preferably 800-1000 ℃, and most preferably 850-1000 ℃; the calcination time is preferably 3-6 h, and more preferably 4-6 h.

The invention also provides the micron spherical TiNb prepared by the preparation method of the technical scheme ₂₄O ₆₂The micron spherical TiNb ₂₄O ₆₂The diameter of (2) is 1 to 2 μm.

The invention also provides the micron spherical TiNb in the technical scheme ₂₄O ₆₂Application in electrode materials.

The application is preferably: mixing the micron spherical TiNb ₂₄O ₆₂Acetylene black and sodium carboxymethyl cellulose are ground according to the mass ratio of 70:20:10Uniformly stirring the mixture to be pasty by using distilled water as a solvent to obtain negative electrode slurry; and coating the slurry on the surface of the copper foil; vacuum drying at 60 deg.C for 12h, and cutting into negative plate with proper size; taking metal lithium as a reference electrode and a counter electrode, taking an electrode material as a working electrode, taking a polypropylene microporous membrane as a diaphragm, and taking 1MLiPF ₆The EC/DEC (volume ratio of 1:1) of the battery is used as electrolyte, a button cell is assembled in a glove box filled with argon, and then electrochemical performance test is carried out on a Land battery test system.

The micron spherical TiNb provided by the invention is combined with the embodiment ₂₄O ₆₂And methods of making and using the same, are described in detail, but are not to be construed as limiting the scope of the invention.