MoTe2 / C flexible electrode material for sodium-ion soft package battery, preparation method and application

Abstract

The application discloses a MoTe2 / C flexible electrode material for sodium ion soft package batteries, a preparation method and application, and belongs to the field of sodium ion battery electrode materials. The raw materials used are common and easily obtained industrial grade products, the equipment is simple, the preparation process is simple, the repeatability is relatively strong, the calcination temperature is relatively low, the overall energy consumption is relatively small, the environment is friendly, and the application is conducive to industrialization. The prepared MoTe2 / C flexible electrode material is significantly different from common MoTe2 materials in appearance, MoTe2 in the composite material is connected into a nanobelt in the form of ultrathin nanosheets, and the thickness of the MoTe2 nanosheet is 3-5 nm. In addition, the MoTe2 / C flexible electrode material provided by the application can be directly used as a sodium ion soft package battery negative electrode material without adding any conductive agent, adhesive, metal current collector, and a sodium ion soft package battery directly assembled therefrom exhibits excellent electrochemical properties.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of sodium ion battery electrode materials, and particularly relates to a MoTe2 / C flexible electrode material for a sodium ion soft package battery, a preparation method and application. BACKGROUND

[0002] Molybdenum ditelluride (MoTe2) is a typical molybdenum-based two-dimensional material, which is widely used in the field of alkali metal battery electrode materials due to its wide layered structure and excellent electronic conductivity.

[0003] At present, researchers have prepared MoTe2 materials with various morphologies and structures through various means such as hydrothermal method and solid phase method. For example, Chinese patent CN202010773212.9 uses MoO3 and TeO2 oxidants as precursors and ethylene glycol as a reducing agent to prepare hexagonal MoTe2 ultra-thin nanosheets by a liquid-phase hydrothermal method. Chinese patent CN202010812577.8 adds a molybdenum source material and a tellurium source material to a MXene dispersion liquid in a certain proportion, and then prepares a MoTe2 / MXene composite material by a hydrothermal reaction, and uses it as a potassium ion battery negative electrode material, which has good electrochemical performance. Chinese patent CN201911010608.1 grinds and mixes MoO3 and tellurium powder, and then prepares a MoTe2 sodium ion electrode material containing three mixed phases by a solid phase method in an argon-hydrogen mixed atmosphere. The above-mentioned MoTe2 nanomaterials have complex reaction processes and high energy consumption in the preparation process. As electrode materials, the problem of large volume change of MoTe2 has not been effectively solved, and they cannot be used as flexible electrode materials. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art and provide a MoTe2 / C flexible electrode material for a sodium ion soft package battery, a preparation method and application.

[0005] To achieve the above-mentioned purpose, the following technical solutions are adopted in the present application:

[0006] A preparation method of a MoTe2 / C flexible electrode material for a sodium ion soft package battery, comprising the following steps:

[0007] 1) 0.3-0.5 grams of a carbon source is added to 5 grams of N,N-dimethylformamide and mixed uniformly to prepare solution A;

[0008] 0.3-0.5 grams of a molybdenum source is added to 5 grams of N,N-dimethylformamide and mixed uniformly to prepare solution B;

[0009] Solution A and solution B are mixed and stirred for 1-2 hours, and a fiber film is spun by an electrospinning method.

[0010] 2) drying the fiber film;

[0011] 3) placing the dried product and the tellurium source in a tube furnace at a mass ratio of 1:(1-3) at different positions, and calcining under an argon-hydrogen atmosphere, the calcining temperature being 380-480 DEG C, and the calcining time being 1-3 hours, to obtain a MoTe2 / C flexible electrode material.

[0012] Further, in step 1), the carbon source is polymethyl acrylate, polyethyl acrylate, poly 2-methyl methacrylate, poly 2-methyl acrylate, polyacrylamide, polymethyl acrylamide or polydimethylamino propyl acrylamide.

[0013] Further, in step 1), the molybdenum source is hexacarbonylmolybdenum or molybdenum pentachloride.

[0014] Further, in step 1), the spinning needle type is 0.21 mm, the positive electrode is connected to the power supply, the negative electrode is wrapped with an aluminum foil, the voltage is 1-15 kV, and the solution injection speed is 0.1 ml / min.

[0015] Further, in step 3), the tellurium source is biphenyl ditelluride or tellurium tetrachloride.

[0016] Further, in step 3), the volume ratio of argon to hydrogen is (16-20):1.

[0017] The temperature is raised at a rate of 1-2 DEG C / min, and after cooling, the residual tellurium source is removed.

[0018] A MoTe2 / C flexible electrode material is prepared according to the above method.

[0019] Further, the MoTe2 / C nanofiber is interwoven, wherein the MoTe2 nanobelt connected by ultrathin nanosheets is dispersed in the carbon material, and the thickness of the MoTe2 nanosheet is 3-5 nm.

[0020] Further, the MoTe2 / C flexible electrode material is used as a sodium ion soft pack battery negative electrode material.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] The present application provides a preparation method of a MoTe2 / C flexible electrode material for a sodium ion soft pack battery, the raw materials used are common and easily obtained industrial grade products, the equipment is simple, the preparation process is simple and convenient, the repeatability is strong, the calcining temperature is low, the overall energy consumption is small, the environment is friendly, and it is conducive to industrialized practical application.

[0023] The MoTe2 / C flexible electrode material provided by the application is significantly different from common MoTe2 materials in morphology, and the MoTe2 in the composite material is connected into a nanobelt by ultrathin nanosheets, and the thickness of the MoTe2 nanosheet is 3-5 nm.

[0024] The application of the MoTe2 / C flexible electrode material provided by the application is used as a negative material of a sodium ion soft package battery, without adding any conductive agent, binder or metal current collector, and under the current density of 100 mAh / g, the sodium ion soft package battery directly assembled by the MoTe2 / C flexible electrode material shows excellent electrochemical properties. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The XRD pattern of the MoTe2 / C flexible electrode material of Example 1 is shown in the figure.

[0026] Figure 2 The scanning electron microscope image of the MoTe2 / C flexible electrode material of Example 1 is shown in the figure.

[0027] Figure 3 The transmission electron microscope image of the MoTe2 / C flexible electrode material of Example 1 is shown in the figure.

[0028] Figure 4 The physical picture of the MoTe2 / C flexible electrode material of Example 1 is shown in the figure.

[0029] Figure 5 The charge-discharge graph of the MoTe2 / C flexible electrode material of Example 1 is shown in the figure. DETAILED DESCRIPTION

[0030] In order to make the person skilled in the art better understand the application scheme, the technical solutions in the embodiments of the application will be described clearly and completely in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the application.

[0031] It is to be understood that the terms "first", "second", and the like, used in the description and the claims of the application, as well as the above-described drawings, are used to distinguish similar objects, and are not necessarily used to describe a particular sequential or chronological order. It is to be understood that the data thus used can be interchanged, where appropriate, so that the embodiments of the application described herein can be carried out in other than the order shown or described herein. Furthermore, the terms "comprising" and "including" and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a list of steps or units can not necessarily be limited to those steps or units that are clearly listed, but can include other steps or units that are not expressly listed or inherent to such process, method, product, or apparatus.

[0032] The application will be further described in detail below with reference to the accompanying drawings:

[0033] Example 1

[0034] 0.5 grams of polyacrylate was added to 5 grams of N,N-dimethylformamide, stirred for 3 hours to prepare solution A; 0.3 grams of molybdenum hexacarbonyl was added to 5 grams of N,N-dimethylformamide, stirred for 3 hours to prepare solution B; solution A and B were mixed and stirred for 2 hours, and then spun into a fiber film; the spinning needle type was 0.21 mm, the positive electrode was connected to the power supply, the negative electrode was wrapped with aluminum foil, the voltage was 15 kV, and the solution injection speed was 0.1 ml / min. The above-mentioned film was vacuum dried at 80℃ for 6 hours. Then the above-mentioned product was placed with diphenyl ditelluride according to a mass ratio of 1:3 in different positions in a tube furnace, and calcination was carried out under an argon-hydrogen atmosphere, the volume ratio of argon to hydrogen was 20:1, the calcination temperature was 480℃, the calcination time was 3 hours, the heating rate was 2℃ / min, and after cooling, the residual diphenyl ditelluride was removed to obtain a MoTe2 / C flexible electrode material.

[0035] Referring to Figure 1 , Figure 1 The XRD pattern of the MoTe2 / C flexible electrode material prepared by the application can be determined from the XRD pattern, and the main component phase composition of the composite material is monoclinic MoTe2, corresponding to standard card number PDF #71-2157.

[0036] Referring to Figure 2 , Figure 2 The scanning electron microscope image of the product of Example 1, wherein the prepared MoTe2 / C flexible electrode material has distinct morphological characteristics, in the form of nanofibers, with a fiber diameter of about 300 nm.

[0037] Referring to Figure 3 , Figure 3The transmission electron microscopy image of the product of Example 1, wherein MoTe2 is connected into nanoribbons by ultrathin nanosheets, and the thickness of the MoTe2 nanosheets is 3-5 nm.

[0038] Referring to Figure 4 , Figure 4 The actual image of the product of Example 1, which shows that the prepared MoTe2 / C flexible electrode material has good flexibility.

[0039] Referring to Figure 5 , Figure 5 The charge-discharge curve of the product of Example 1, wherein the prepared MoTe2 / C flexible electrode material is directly used as a sodium ion soft pack battery negative electrode material without adding any conductive agent, binder, metal current collector, and is matched with a positive electrode material sodium vanadium phosphate, sodium perchlorate electrolyte, and is directly assembled into a sodium ion soft pack battery for testing. At a current density of 100 mA / g, the battery shows excellent charge-discharge properties.

[0040] Example 2

[0041] 0.3 grams of poly 2-methyl methacrylate was added to 5 grams of N,N-dimethylformamide, stirred for 2 hours to prepare solution A; 0.5 grams of molybdenum pentachloride was added to 5 grams of N,N-dimethylformamide, stirred for 2 hours to prepare solution B; solution A and B were mixed and stirred for 1 hour, and then spun into a fiber film; wherein the spinning needle type was 0.21 mm, the positive electrode was connected to the power supply, the negative electrode was wrapped with aluminum foil, the voltage was 14 kV, and the solution injection speed was 0.1 ml / min. The above-mentioned film was vacuum dried at 70°C for 5 hours. Then the above-mentioned product and tellurium tetrachloride were placed in a tube furnace at different positions according to a mass ratio of 1:2, and calcined under an argon-hydrogen atmosphere, wherein the volume ratio of argon to hydrogen was 18:1, the calcination temperature was 470°C, the calcination time was 2 hours, the heating rate was 2°C / min, and after cooling, the residual tellurium tetrachloride was removed to obtain a MoTe2 / C flexible electrode material.

[0042] Example 3

[0043] 0.4 grams of polyacrylamide was added into 5 grams of N,N-dimethylformamide, stirred for 3 hours to prepare solution A; 0.4 grams of molybdenum hexacarbonyl was added into 5 grams of N,N-dimethylformamide, stirred for 2 hours to prepare solution B; solution A and B were mixed and stirred for 1 hour, and then spun into a fiber film; the spinning needle type was 0.21 mm, the positive electrode was connected to the power supply, the negative electrode was wrapped with aluminum foil, the voltage was 1 kV, and the solution injection speed was 0.1 ml / min. The above-mentioned film was vacuum dried at 50℃ for 1 hour. Then the above-mentioned product and biphenyl ditelluride were placed in a tube furnace at different positions according to a mass ratio of 1:1, calcined under an argon-hydrogen atmosphere, the volume ratio of argon to hydrogen was 16:1, the calcination temperature was 380℃, the calcination time was 1 hour, the heating rate was 1℃ / min, and after cooling, the residual biphenyl ditelluride was removed to obtain a MoTe2 / C flexible electrode material.

[0044] Example 4

[0045] 0.5 grams of polydimethylaminopropyl acrylamide was added into 5 grams of N,N-dimethylformamide, stirred for 3 hours to prepare solution A; 0.3 grams of molybdenum pentachloride was added into 5 grams of N,N-dimethylformamide, stirred for 2 hours to prepare solution B; solution A and B were mixed and stirred for 2 hours, and then spun into a fiber film; the spinning needle type was 0.21 mm, the positive electrode was connected to the power supply, the negative electrode was wrapped with aluminum foil, the voltage was 15 kV, and the solution injection speed was 0.1 ml / min. The above-mentioned film was vacuum dried at 80℃ for 6 hours. Then the above-mentioned product and tellurium tetrachloride were placed in a tube furnace at different positions according to a mass ratio of 1:3, calcined under an argon-hydrogen atmosphere, the volume ratio of argon to hydrogen was 20:1, the calcination temperature was 480℃, the calcination time was 3 hours, the heating rate was 2℃ / min, and after cooling, the residual tellurium tetrachloride was removed to obtain a MoTe2 / C flexible electrode material.

[0046] The polyacrylate, poly 2-methyl acrylate, polyacrylamide, and polydimethylaminopropyl acrylamide in Example 1-Example 4 can be replaced by polyacrylate, poly 2-methyl acrylate, and polymethacrylamide.

[0047] The present application uses cheap and readily available raw materials and simple and efficient preparation conditions to complete the preparation of the MoTe2 / C flexible electrode material, and a unique kind of amorphous carbon material coated 3-5 nm thick MoTe2 ultra-thin nanosheet connected nanobelt is obtained, which has good electrochemical performance as a sodium ion soft pack battery negative electrode material.

[0048] The above content only illustrates the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made on the basis of the technical solution according to the technical idea of the present application falls within the protection scope of the claims of the present application.

Claims

1. A method for preparing a MoTe2 / C flexible electrode material for a sodium-ion soft-pack battery, characterized in that, The method comprises the following steps: 1) 0.3-0.5 g of carbon source is added into 5 g of N,N-dimethylformamide to mix uniformly to prepare solution A; 0.3-0.5 g of molybdenum source is added into 5 g of N,N-dimethylformamide to mix uniformly to prepare solution B; solution A and solution B are mixed and stirred for 1-2 hours, and a fiber film is spun by electrospinning; 2) the fiber film is dried; 3) the dried product and tellurium source are placed in different positions of a tube furnace according to a mass ratio of 1: (1-3), and calcination is performed under an argon-hydrogen atmosphere, the calcination temperature is 380-480 ℃, and the calcination time is 1-3 hours to obtain a MoTe2 / C flexible electrode material; in step 1), the carbon source is polymethyl acrylate, polyethyl acrylate, poly 2-methyl methyl acrylate, poly 2-methyl ethyl acrylate, polyacrylamide, polymethyl acrylamide or polydimethylamino propyl acrylamide; the molybdenum source is hexacarbonylmolybdenum or molybdenum pentachloride; in step 3), the volume ratio of argon to hydrogen is (16-20): 1; the heating rate is 1-2 ℃ / min, and the residual tellurium source is removed after cooling; the MoTe2 / C flexible electrode material is composed of MoTe2 / C nanofibers interwoven, wherein MoTe2 nanobands connected by ultrathin nanosheets are dispersed in carbon materials, and the thickness of MoTe2 nanosheets is 3-5 nm.

2. The method according to claim 1, wherein the MoTe2 / C flexible electrode material for the sodium-ion soft-pack battery is prepared by the method characterized in that, in step 1), the type of the spinning needle is 0.21 mm, the positive electrode of the power supply is connected, the negative electrode is wrapped with aluminum foil, the voltage is 1-15 kV, and the solution injection speed is 0.1 ml / min.

3. The method according to claim 1, wherein the MoTe2 / C flexible electrode material for the sodium-ion soft-pack battery is prepared by the method characterized in that, in step 3), the tellurium source is biphenyl ditelluride or tellurium tetrachloride.

4. A MoTe2 / C flexible electrode material, characterized in that, The MoTe2 / C flexible electrode material is prepared by the method according to any one of claims 1-3. 5.The application of MoTe 2 / C flexible electrode material according to claim 4, characterized in that, The MoTe2 / C flexible electrode material is used as a negative electrode material of a sodium ion soft battery.

Images