Titanium nitride-chloride nanomaterial for electrochemical energy storage and preparation method and application thereof

Abstract

The application relates to a titanium nitride-chloride nanomaterial for electrochemical energy storage and a preparation method and application thereof. The titanium nitride-chloride nanomaterial for electrochemical energy storage has a nanosheet structure or a flower-shaped macrostructure composed of the nanosheet structure; the sheet layer thickness of the nanosheet structure is 2nm-100nm, and the sheet layer diameter is 20nm-1mu m; and the macroscopic size of the flower-shaped macrostructure is 0.1mu m-5mu m.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nanomaterials and electrochemical energy storage, in particular to a titanium nitride chloride nanomaterial with excellent chemical stability, high electronic conductivity, high ionic conductivity and high rate performance applied in lithium ion batteries and a preparation method thereof, which is mainly used in the field of energy storage such as lithium ion batteries and supercapacitors. BACKGROUND

[0002] Transition metal nitride halide (MNX) is a sandwich-like layered compound composed of metal nitride layer and halogen layer. Due to this special crystallographic structure, transition metal nitride halide has very peculiar physical properties. Transition metal nitride halide has two crystal structures of α type and β type, but under normal conditions, both crystal forms show semiconductor characteristics, and the band gap is from 0.6 eV to 4.0 eV. When intercalation reaction is carried out on the material, under certain conditions, the material will undergo superconducting transition, forming A x MNCI (A: small molecule compound, alkali metal element). Among transition metal nitride halides, titanium nitride chloride of α type has attracted widespread attention due to its suitable band gap and excellent superconducting performance after intercalation. Titanium nitride chloride has a narrow band gap of 0.9 eV, and suitable interlayer spacing is conducive to the intercalation reaction of alkali metals and small molecule organic matter. These characteristics further expand the application of titanium nitride chloride in the fields of catalysis, energy storage and solar cells.

[0003] Currently, the research on transition metal nitride halide in the literature is also focused on the intercalation of the material to achieve superconducting transition, and the research on transition metal nitride halide in the energy storage direction is less. The metal nitride halide can well accommodate metal ions or small molecule organic matters due to its layered characteristics and large interlayer spacing. This characteristic is very good for ion energy storage, so the transition metal nitride halide will be a very potential energy storage material. Because the atomic mass of Ti atom is small, and the interlayer spacing of TiNCl is as high as 0.78 nm, it can well store lithium, so it is very suitable for lithium ion battery. However, the research on TiNCl is mainly focused on bulk materials. The diffusion speed and diffusion distance of Li ions in the bulk material are small, so it is difficult to achieve fast lithium ion deintercalation (J. Electrochem. Soc. 2004, 151, A843). The preparation process of titanium nitride chloride usually uses a two-step method, that is, a poorly crystalline TiNCl material is obtained by chemical vapor deposition, and then the crystallinity of the material is improved by high temperature calcination. Using this method, a high crystallinity TiNCl bulk material can be obtained. However, this method has a long preparation period, usually more than one week, and the control of temperature and time during high temperature calcination needs to be relatively accurate, and the yield of the obtained product is small, so it is difficult to achieve mass production. Therefore, there is a lack of a method for preparing a nano-sized titanium nitride chloride material suitable for high-performance lithium ion energy storage in this direction. SUMMARY

[0004] Technical problems to be solved:

[0005] In order to prepare an electrode material with fast lithium deintercalation characteristics and capable of being applied in high-performance lithium ion battery, the application provides a titanium nitride chloride nano material with excellent chemical stability, high electronic conductivity, high ionic conductivity and high rate performance and a preparation method. A titanium source and a nitrogen source are used as raw materials, and a one-step preparation of the material is realized by chemical vapor transmission. The preparation method is simple, the preparation time is short, and the preparation efficiency is high.

[0006] Specific technical solutions:

[0007] In one aspect, the application provides a titanium nitride chloride nano material for electrochemical energy storage, which has a sheet-like nano structure (i.e. a nanosheet structure) or a flower-like macro structure composed of sheet-like nano structures; the sheet thickness of the sheet-like nano structure is 2 nm to 100 nm, and the sheet diameter is 20 nm to 1 μm; the macro size of the flower-like macro structure is 0.1 μm to 5 μm.

[0008] Preferably, the titanium nitride chloride nano material is used as a narrow-bandgap semiconductor material, and has excellent electronic conductivity, and the electronic conductivity is 1.0 to 500 mS·cm.-1 .

[0009] Preferably, the titanium nitride nanomaterial possesses lithium-ion diffusion capability, with a lithium-ion diffusion coefficient of 1.0 × 10⁻⁶. -11 ~1.0×10 -9 cm 2 s -1 .

[0010] Preferably, the titanium nitride nanomaterial exhibits a capacitance of 150–800 mAh·g under charge-discharge rates of 1C–100C. -1 The cyclic reversible capacity.

[0011] Preferably, when the titanium nitride nanomaterial is used in lithium-ion battery energy storage, the pseudocapacitance accounts for 90% to 100%.

[0012] On the other hand, the present invention provides a method for preparing titanium nitride nanomaterials for electrochemical energy storage, using titanium source and nitrogen source as reaction raw materials, reacting in a protective atmosphere at 100-800°C for 1-600 minutes to obtain the titanium nitride nanomaterials for electrochemical energy storage.

[0013] Preferably, the titanium source is at least one of titanium tetrachloride, ammonium hexachlorotitanate, titanium oxysulfate, tetrabutyl titanate, tetraethyl titanate, tetraisopropyl titanate, and titanium isopropoxide; and the nitrogen source is at least one of ammonia, ammonium chloride, ethylenediamine, ammonium sulfate, urea, and ammonium nitrate.

[0014] Preferably, the protective atmosphere is an inert atmosphere, preferably an argon atmosphere; the gas flow rate of the protective atmosphere is 1 to 1000 sccm (ml / min).

[0015] In another aspect, the present invention provides an application of titanium nitride nanomaterials for electrochemical energy storage in the field of electrochemical energy storage, wherein the titanium nitride nanomaterials are used in lithium-ion batteries and supercapacitors.

[0016] Beneficial effects:

[0017] This invention discloses a titanium nitride nanomaterial with excellent chemical stability, high electronic conductivity, high ionic conductivity, and high rate performance for use in lithium-ion batteries, as well as its preparation method. A one-step chemical vapor deposition method is used to prepare highly crystalline layered titanium nitride nanomaterials. The resulting titanium nitride nanomaterials exhibit an intercalated flower-like structure and can be used in electrochemical energy storage. Furthermore, this preparation method is simple, easy to control, has a short preparation time, and can achieve high single-batch yield. Attached Figure Description

[0018] Figure 1X-ray electron diffraction pattern of the product prepared at different temperatures, the vertical coordinate is the intensity of the collected signal, dimensionless, the horizontal coordinate is 2 times of the X-ray incident angle (2 Theta), unit: degree;

[0019] Figure 2 X-ray electron diffraction pattern of the titanium nitride chloride nanomaterial prepared and after one week;

[0020] Figure 3 The curve of the electronic conductivity of the titanium nitride chloride nanomaterial with temperature, the vertical coordinate is the electronic conductivity, unit: mS·cm -1 , the horizontal coordinate is the temperature, unit: Kelvin (K) ;

[0021] Figure 4 The morphology of the titanium nitride chloride nanomaterial;

[0022] Figure 5 The comparison chart of the electronic conductivity and lithium ion diffusion coefficient of the titanium nitride chloride nanomaterial (TiNCl) and lithium titanate (Li4Ti5O 12 ), the left vertical coordinate is the electronic conductivity, unit: mS·cm -1 , the right vertical coordinate is the lithium ion diffusion coefficient, unit: cm 2 ·s -1 , the horizontal coordinate is marked with the titanium nitride chloride nanomaterial (TiNCl) and lithium titanate (Li4Ti5O 12 ) ;

[0023] Figure 6 The lithium battery cycle performance of the titanium nitride chloride nanomaterial at different rates, the vertical coordinate is the cycle reversible capacity (Capacity), unit: mAh·g -1 , the horizontal coordinate is the cycle number, unit: none. DETAILED DESCRIPTION

[0024] The present application is further illustrated by the following embodiments, which should be understood as merely illustrating the present application, but not limiting the present application.

[0025] In the present disclosure, the titanium nitride chloride material for electrochemical energy storage has a nanoscale structure of sheet layer, the sheet layer thickness is from 2 to 100 nm, and the sheet layer size can be from 20 nm to 1 μm. Alternatively, the titanium nitride chloride material for electrochemical energy storage has a flower-shaped macrostructure formed by the intersection of the nanoscale structure of sheet layer, and the macroscopic size can be from 0.1 μm to 5 μm.

[0026] In an optional embodiment, the titanium nitride-chloride nanomaterial has excellent electronic conductivity, and the electronic conductivity is 1.0-500 mS·cm measured by using a comprehensive physical property measurement system (PPMS). -1 .

[0027] In an optional embodiment, the titanium nitride-chloride nanomaterial has excellent lithium ion diffusion capacity, and the lithium ion diffusion coefficient is 1.0*10 -11 -1.0*10 -9 cm 2 s -1 .

[0028] In an optional embodiment, the titanium nitride-chloride nanomaterial has excellent rate performance. The performance of the material at different rates is measured by using a battery comprehensive performance tester, and the material shows a cycle reversible capacity of 150-800 mAh·g -1 under the conditions of 1C-100C rate charging and discharging.

[0029] In an optional embodiment, the titanium nitride-chloride nanomaterial has a pseudo-capacitance ratio of 90%-100% when applied in lithium ion battery energy storage.

[0030] In the present application, the titanium nitride-chloride nanomaterial is prepared by chemical vapor deposition under high temperature conditions. Specifically, titanium source and nitrogen source are selected as reaction raw materials, argon is introduced and heated to a certain reaction temperature, and then cooled to room temperature after a certain reaction time to obtain the titanium nitride-chloride nanomaterial.

[0031] In an optional embodiment, the titanium source used is titanium tetrachloride, ammonium hexachlorotitanate, titanyl sulfate, tetrabutyl titanate, tetraethyl titanate, tetraisopropyl titanate, and titanium isopropoxide.

[0032] In an optional embodiment, the nitrogen source used is ammonia, ammonium chloride, ethylenediamine, ammonium sulfate, urea, and ammonium nitrate.

[0033] In an optional embodiment, the reaction temperature can be 100-800℃, the gas flow rate is 1-1000 sccm (milliliter / minute), and the reaction time is 1-600 minutes.

[0034] In the present application, the titanium nitride-chloride nanomaterial has good chemical stability and excellent electrochemical properties, and can be widely used in the fields of electrochemical energy storage such as lithium ion batteries and supercapacitors.

[0035] The following further illustrates the embodiments in detail. It should also be understood that the following embodiments are only used to further illustrate the present application, and cannot be understood as limiting the scope of the present application. Some non-essential improvements and adjustments made by those skilled in the art according to the above content of the present application are within the scope of the present application. The specific process parameters and the like described below are only one example in the appropriate range, i.e. those skilled in the art can make appropriate selection within the range according to the description herein, and are not limited to the specific values of the following examples.

[0036] Example 1

[0037] Titanium tetrachloride was used as a raw material for the reaction. After heating to a reaction temperature of 400℃ in a chemical vapor deposition reaction furnace, argon and ammonia were introduced at flow rates of 300 and 200 sccm (milliliter / minute), respectively. The chemical vapor deposition reaction was carried out for 180 minutes, and then cooled to room temperature. A yellow-green titanium nitride chloride nanomaterial was obtained. The results show that the material has high crystallinity and can exhibit all the main diffraction peaks of titanium nitride chloride. Figure 1 Figure 2 The titanium nitride chloride nanomaterial remained unchanged in structure after being placed in air for a week. The electronic conductivity of the titanium nitride chloride nanomaterial was 22.9 mS·cm -1 Figure 3 The micro-morphology of the titanium nitride chloride nanomaterial was a flower-like morphology formed by the intersection of thin layers. Figure 4 The size of the flake layer was 200 nm, the average thickness of the thin layer was 6.2 nm, the (001) crystal plane spacing of the material was about 0.74 nm, and each flake was composed of about 10 monolayers of titanium nitride chloride. The lithium ion diffusion coefficient of titanium nitride chloride was 3.04×10 -11 cm 2 ·s -1 Figure 5 The lithium ion battery performance test was carried out using the titanium nitride chloride nanomaterial as the negative electrode of the battery. Figure 6 At 1C, 5C, 10C, 20C, and 50C rates, it showed high capacity of 450.2, 342.7, 298.3, 283.8, 261.8, and 240.0 mAh·g-1, respectively, and the pseudo-capacitance ratio reached 99%.

[0038] Example 2

[0039] ​​​The titanium oxynitride nanomaterials were obtained by using titanium oxysulfate as the raw material, heating to a reaction temperature of 200℃ in a chemical vapor deposition reaction furnace, introducing argon and ammonia gas at a flow rate of 500 sccm (milliliter / minute) respectively, and performing a chemical vapor deposition reaction for 500 minutes. The titanium oxynitride nanomaterials were yellow-green in color. The results showed that the material had poor crystallinity, with only weak (001) diffraction peaks of titanium oxynitride. The titanium oxynitride nanomaterials remained unchanged in structure after being placed in air for a week. The electronic conductivity of the titanium oxynitride nanomaterials was 12 mS·cm -1 . The micro-morphology of the titanium oxynitride nanomaterials was a flower-like morphology formed by the intersection of thin layers, with a sheet size of 500 nm and an average thickness of the thin layers of 9.2 nm. The lithium ion diffusion coefficient of the titanium oxynitride was 2.14×10 -11 cm 2 ·s -1 . The lithium ion battery performance test using the titanium oxynitride nanomaterials as the negative electrode showed high capacity of 480.1, 322.1, 277.5, 243.2, 221.0, 211.3 and 200.5 mAh·g -1 at 1C, 5C, 10C, 20C, 50C and 100C, respectively, with a pseudo-capacitance ratio of 97%.

[0040] Example 3

[0041] The titanium oxynitride nanomaterials were obtained by using titanium tetrabutoxide and urea as the raw material, heating to a reaction temperature of 600℃ in a chemical vapor deposition reaction furnace, introducing argon gas at a flow rate of 600 sccm (milliliter / minute), and performing a chemical vapor deposition reaction for 400 minutes. The titanium oxynitride nanomaterials were yellow-green in color. The results showed that the material had high crystallinity. The titanium oxynitride nanomaterials remained unchanged in structure after being placed in air for a week. The electronic conductivity of the titanium oxynitride nanomaterials was 112 mS·cm -1 . The micro-morphology of the titanium oxynitride nanomaterials was a flower-like morphology formed by the intersection of thin layers, with a sheet size of 800 nm and an average thickness of the thin layers of 12.6 nm. The lithium ion diffusion coefficient of the titanium oxynitride was 3.80×10 -10 cm 2 ·s -1 . The lithium ion battery performance test using the titanium oxynitride nanomaterials as the negative electrode showed high capacity of 550.3, 488.2, 450.5, 420.1, 410.0, 399.5 and 388.1 mAh·g -1 at 1C, 5C, 10C, 20C, 50C and 100C, respectively, with a pseudo-capacitance ratio of 98%.

[0042] Example 4

[0043] The titanium nitride chloride nanomaterial was obtained by using titanium isopropylate and ethylenediamine as raw materials, heating to a reaction temperature of 700 DEG C in a chemical vapor deposition reaction furnace, introducing argon gas at a flow rate of 600 sccm (milliliter / minute), and performing a chemical vapor deposition reaction for 250 minutes. The titanium nitride chloride nanomaterial was yellow-green. The results show that the material has high crystallinity. The titanium nitride chloride nanomaterial remained unchanged in structure after being placed in air for one week. The electronic conductivity of the titanium nitride chloride nanomaterial was 66 mS·cm -1 The micro-morphology of the titanium nitride chloride nanomaterial was a flower-like morphology formed by the intersection of thin layers, the size of the sheet layer was 86 nm, and the average thickness of the thin layer was 4.6 nm. The lithium ion diffusion coefficient of the titanium nitride chloride was 1.50 x 10 -10 cm 2 ·s -1 -1 . The lithium ion battery performance test using the titanium nitride chloride nanomaterial as the negative electrode showed high capacity of 490.0, 468.5, 440.9, 418.5, 407.0, 388.1 and 357.1 mAh·g -1 at 1C, 5C, 10C, 20C, 50C and 100C, respectively, and the proportion of pseudo-capacitance reached 95%.

Claims

1. A titanium nitride-chloride nanomaterial for electrochemical energy storage, characterized in that, The nitrogen-chlorine titanium nanomaterial for electrochemical energy storage has a flower-like macrostructure composed of nanosheet structures; the nanosheet structures have a sheet layer thickness of 2-100 nm and a sheet layer diameter of 20-1 microns; and the flower-like macrostructure has a macroscopic size of 0.1-5 microns. 2.The titanium nitride-chloride nanomaterial for electrochemical energy storage according to claim 1, characterized in that, The electronic conductivity of the titanium nitride-chloride nanomaterial is 1.0-500 mS·cm -1 . 3.The titanium nitride-chloride nanomaterial for electrochemical energy storage according to claim 1, characterized in that, The nitrogen-chlorine titanium nanomaterial has lithium ion diffusion capacity, and the lithium ion diffusion coefficient is 1.0*10 -11 ~1.0*10 -9 cm 2 s -1 .

4. A method for preparing the titanium nitride-chloride nanomaterial for electrochemical energy storage according to any one of claims 1-3, characterized in that, The nitrogen-chlorine titanium nanomaterial for electrochemical energy storage is obtained by using a titanium source and a nitrogen source as reaction raw materials, reacting at 100-800 DEG C for 1-600 minutes in a protective atmosphere; the titanium source is at least one of titanium tetrachloride, ammonium hexachlorotitanate, titanyl sulfate, tetrabutyl titanate, tetraethyl titanate, tetraisopropyl titanate, and titanium isopropoxide; the nitrogen source is at least one of ammonia, ammonium chloride, ethylenediamine, ammonium sulfate, urea, and ammonium nitrate; and the protective atmosphere is an inert atmosphere. 5.The method for preparing titanium nitride-chloride nanomaterials according to claim 4, characterized in that, The protective atmosphere is an argon atmosphere, and the gas flow of the protective atmosphere is 1-1000 sccm.

6. The use of the electrochemical energy storage titanium nitride-chloride nanomaterial according to any one of claims 1-3 in the field of electrochemical energy storage, characterized in that, The nitrogen-chlorine titanium nanomaterial is applied in a lithium ion battery or a supercapacitor.

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