Preparation method of MoS2 / TiO2 material and application of lithium ion battery thereof

Abstract

The application relates to a preparation method of a MoS2 / TiO2 material and application of the MoS2 / TiO2 material to a lithium ion battery, and the method comprises the following steps: preparing a carbon fiber cloth loaded MoS2 material and a carbon fiber cloth loaded MoS2 / TiO2 material through a hydrothermal method.The application has the beneficial effects that the conductivity of a transition metal compound is improved, the agglomeration in the charging and discharging process is inhibited, and finally the energy storage performance of a lithium ion battery negative electrode material is improved.

Description

Technical Field

[0001] This invention relates to the field of new materials technology for lithium-ion battery anodes, and more specifically, to a method for preparing MoS2 / TiO2 material and its application in lithium-ion batteries. Background Technology

[0002] Currently, graphite materials are widely used as anode energy storage materials in lithium-ion batteries, but their capacity is relatively low, only 372 mAh / g, which cannot meet the current demand for high-energy-density batteries in the new energy industry. Compared with group IV elements, transition metal compounds have higher theoretical specific capacity (the theoretical capacity of MoS2 is approximately 670 mAh / g) and relatively smaller volume expansion during charge and discharge. However, pure MoS2 undergoes agglomeration and phase structure changes during lithium insertion and extraction, which reduces its lithium storage capacity during charge and discharge cycles. Transition metal compounds typically have relatively low electrical conductivity; for example, the conductivity of the semiconductor 2H phase MoS2 is very low (10⁻⁶ mAh / g). -4 The low efficiency (S / cm) will further limit its application in lithium-ion batteries.

[0003] To address the issues of low conductivity and agglomeration in transition metal compounds, current research focuses on combining them with carbon materials to improve conductivity, combining different metal compounds, and designing special morphologies to suppress agglomeration during lithium insertion / extraction. Current techniques often employ the combination of powdered carbon materials with transition metal compounds, but this has not effectively solved the agglomeration problem during charge / discharge. The combination of transition metal compounds typically involves complex methods, increasing experimental costs and limiting further applications. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and to propose a method for preparing MoS2 / TiO2 materials and their application in lithium-ion batteries.

[0005] In a first aspect, a method for preparing MoS2 / TiO2 materials is provided, including:

[0006] S1. Weigh appropriate amounts of ammonium molybdate tetrahydrate and thiourea as solutes, and 60-70 ml of deionized water as solvent. Stir at room temperature for 10-30 min to obtain the first precursor solution, and sonicate the first precursor solution for 30-60 min.

[0007] S2, from 2×4 to 4×7cm 2The carbon fiber cloth within the range is placed in the first precursor solution and then transferred to a high-temperature and high-pressure reactor. It is kept at 180-200℃ for 20-30 hours. After the reaction is completed, the carbon fiber cloth is taken out, washed several times with deionized water and ethanol, and dried at 50-70℃ for 8-12 hours to obtain carbon fiber cloth loaded with MoS2 material for battery assembly.

[0008] S3. Take an appropriate amount of 5-15 ml of glycerol and dissolve it in 55-65 ml of anhydrous ethanol. Stir for 10-30 min, add an appropriate amount of 0.5-1.5 ml of tetrabutyl titanate, and continue stirring for 20-50 min to obtain the second precursor solution. Then, sonicate the second precursor solution for 30-60 min.

[0009] S4. Place the carbon fiber cloth-loaded MoS2 material into the second precursor solution, and finally transfer it into a high-temperature and high-pressure reactor. Keep it at 160-180℃ for 12-20 hours. After the reaction is completed, take out the carbon fiber cloth-loaded MoS2 material, wash it several times with deionized water and ethanol, and dry it at 50-70℃ for 8-12 hours to obtain the carbon fiber cloth-loaded MoS2 / TiO2 material for battery assembly.

[0010] Preferably, in S1, the concentration of ammonium molybdate tetrahydrate in the first precursor solution is 1.69-1.71 wt%, the concentration of thiourea is 1.57-3.11 wt%, and the mass percentage ratio of ammonium molybdate tetrahydrate to thiourea is in the range of 0.54-1.09.

[0011] In a second aspect, a carbon fiber cloth-supported MoS2 material is provided, which is prepared by the method for preparing MoS2 / TiO2 material described in the first aspect.

[0012] Thirdly, a carbon fiber cloth-supported MoS2 / TiO2 material is provided, characterized in that it is prepared by the method for preparing the MoS2 / TiO2 material.

[0013] Fourthly, an application of carbon fiber cloth-supported MoS2 material as described in the first aspect in lithium-ion batteries is provided.

[0014] Fifthly, an application of carbon fiber cloth-supported MoS2 / TiO2 material as described in the first aspect in lithium-ion batteries is provided.

[0015] The beneficial effects of this invention are: the carbon fiber cloth-supported MoS2 / TiO2 material provided by this invention can improve energy storage performance, enhance the conductivity of transition metal compounds, suppress agglomeration during the charging and discharging process, and ultimately improve the long cycle and rate performance of lithium-ion battery anode materials. Attached Figure Description

[0016] Figure 1 This is a scanning electron microscope image of carbon fiber cloth.

[0017] Figure 2 Scanning electron microscope image of MoS2 material loaded on carbon fiber cloth;

[0018] Figure 3 Scanning electron microscope image of MoS2 / TiO2 material loaded on carbon fiber cloth;

[0019] Figure 4 A schematic diagram of the rate performance of the charge-discharge curves of MoS2 / TiO2 material loaded on carbon fiber cloth. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that those skilled in the art can make several modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0021] Example 1:

[0022] Preparation of MoS2 material supported on carbon fiber cloth:

[0023] First, weigh 1235 mg of ammonium molybdate tetrahydrate and 1142 mg of thiourea, dissolve them in 60 ml of deionized water, stir for 10 min at room temperature, and then sonicate for 30 min to obtain the precursor solution. Cut a 3*5 cm [piece of material] -2 The carbon fiber cloth was placed in the precursor solution and then transferred to a high-temperature, high-pressure reactor, where it was kept at 180°C for 30 hours. After the reaction was completed, the carbon fiber cloth was removed (e.g., ...). Figure 1 As shown), the carbon fiber cloth-supported MoS2 material (as shown) was washed twice with deionized water and ethanol, and then dried at a constant temperature of 50°C for 12 hours to obtain a material that can be directly used for battery assembly. Figure 2 As shown in the figure, the material is a uniformly vertically grown MoS2 nanosheet.

[0024] Preparation of MoS2 / TiO2 materials supported on carbon fiber cloth:

[0025] First, 10 ml of glycerol and 60 ml of ethanol were measured and stirred for 10 min to obtain a homogeneous solution. Then, 0.5 ml of tetrabutyl titanate was added, and stirring was continued for 10 min. Next, the carbon fiber cloth-supported MoS2 material prepared by the above method was added, and finally, the mixture was transferred to a high-temperature and high-pressure reactor and kept at 160℃ for 20 h. After the reaction, the carbon fiber cloth was removed, washed several times with deionized water and ethanol, and dried at 50℃ for 12 h to obtain carbon fiber cloth-supported MoS2 / TiO2 material that can be directly used for battery assembly (e.g., ...). Figure 3(As shown). Therefore, this application further composites TiO2 material with MoS2 material supported on carbon fiber cloth, changing the original nanosheet morphology and obtaining a composite material of nanowires and nanosheets. The rate performance of the charge-discharge curve of the carbon fiber cloth-supported MoS2 / TiO2 material is shown in the figure. Figure 4 As shown, curves with circular markers represent charging rate performance, while curves with square markers represent discharging rate performance.

[0026] Example 2:

[0027] Preparation of MoS2 material supported on carbon fiber cloth:

[0028] First, weigh 1235 mg of ammonium molybdate tetrahydrate and 2283 mg of thiourea, dissolve them in 70 ml of deionized water, stir at room temperature for 30 min, and then sonicate for 60 min to obtain the precursor solution. Cut a 4*6 cm [piece of material / material]... -2 The carbon fiber cloth was placed in the precursor solution and then transferred to a high-temperature and high-pressure reactor, where it was kept at 200°C for 24 hours. After the reaction was completed, the carbon fiber cloth was removed, washed twice with deionized water and ethanol, and dried at 60°C for 8 hours to obtain carbon fiber cloth-loaded MoS2 material that can be directly used for battery assembly.

[0029] Preparation of MoS2 / TiO2 materials supported on carbon fiber cloth:

[0030] First, 15 ml of glycerol and 55 ml of ethanol were measured and stirred for 20 min to obtain a homogeneous solution. Then, 1.5 ml of tetrabutyl titanate was added, and stirring was continued for 30 min. Subsequently, the carbon fiber cloth-supported MoS2 material prepared by the above method was added, and finally, the mixture was transferred to a high-temperature and high-pressure reactor and kept at 180°C for 12 h. After the reaction was completed, the carbon fiber cloth was removed, washed several times with deionized water and ethanol, and dried at 60°C for 8 h to obtain carbon fiber cloth-supported MoS2 / TiO2 material that can be directly used for battery assembly.

Claims

1. A method for preparing a MoS2 / TiO2 material, characterized in that, include: S1. Weigh appropriate amounts of ammonium molybdate tetrahydrate and thiourea as solutes, and 60-70 ml of deionized water as solvent. Stir at room temperature for 10-30 min to obtain the first precursor solution, and sonicate the first precursor solution for 30-60 min. In S1, the concentration of ammonium molybdate tetrahydrate in the first precursor solution is 1.69-1.71 wt%, the concentration of thiourea is 1.57-3.11 wt%, and the mass percentage ratio of ammonium molybdate tetrahydrate to thiourea is in the range of 0.54-1.

09. S2, from 2×4 to 4×7 cm 2 The carbon fiber cloth within the range is placed in the first precursor solution and then transferred to a high-temperature and high-pressure reactor. It is kept at 180-200℃ for 20-30 h. After the reaction is completed, the carbon fiber cloth is taken out, washed several times with deionized water and ethanol, and dried at 50-70℃ for 8-12 h to obtain carbon fiber cloth loaded with MoS2 material for battery assembly. S3. Take an appropriate amount of glycerol (5-15 ml) and dissolve it in 55-65 ml of anhydrous ethanol. Stir for 10-30 min, add an appropriate amount of tetrabutyl titanate (0.5-1.5 ml), and continue stirring for 20-50 min to obtain the second precursor solution. Then, sonicate the second precursor solution for 30-60 min. S4. Place the carbon fiber cloth-loaded MoS2 material into the second precursor solution, and finally transfer it into a high-temperature and high-pressure reactor. Keep it at 160-180 ℃ for 12-20 h. After the reaction is completed, take out the carbon fiber cloth-loaded MoS2 material, wash it several times with deionized water and ethanol, and dry it at 50-70 ℃ for 8-12 h to obtain the carbon fiber cloth-loaded MoS2 / TiO2 material for battery assembly.

2. A carbon fiber cloth-supported MoS2 / TiO2 material, characterized in that, It is prepared by the method for preparing MoS2 / TiO2 material according to claim 1.

3. An application of the carbon fiber cloth-supported MoS2 / TiO2 material as described in claim 1 in lithium-ion batteries.

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