Molybdenum oxide / titanium nitride coated graphene composite material as well as preparation method and application thereof
Through the preparation of molybdenum oxide/titanium nitride@graphene composite materials, the problem of low lithium storage performance of lithium-ion batteries at low temperatures is solved, and higher battery cycle stability and capacity are achieved.
Patent Information
- Application Number
- CN202510033976.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-09
- Publication Date
- 2025-04-15
AI Technical Summary
Existing lithium-ion batteries have low lithium storage performance in low temperature environments, especially the stability and high capacity provided by pure SnO2 electrodes at sub-zero temperatures are insufficient, and the circulation performance of molybdenum oxide and titanium nitride materials is poor.
Molybdenum oxide/titanium nitride@graphene composite material is prepared by combining molybdenum oxide and titanium nitride, combining graphene modification, and improving its electron conduction ability and structural stability.
The composite material significantly improves the lithium storage performance of lithium-ion batteries at low temperatures, enhances the cycle stability and capacity of the batteries, and solves the problem of low battery performance at low temperatures.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of new energy and new materials, and in particular to a molybdenum oxide / titanium nitride@graphene composite material and a preparation method and application thereof. Background Art
[0002] Low-temperature lithium storage electrode materials are key components in lithium-ion batteries (LIBs). Their performance directly affects the battery's lithium storage capacity and overall battery performance in low-temperature environments. Common low-temperature lithium storage electrode materials include SnO 2 Base anode material, SnO 2 The negative electrode can provide stable and high capacity at sub-zero temperatures. In particular, at temperatures below 13 °C, the polymorphic transformation of Sn helps to provide Li + establish a faster transmission channel, but due to the thermally induced coarsening of Sn, pure SnO 2 The electrode has poor cycling stability and reversibility of conversion reactions at room temperature and above, resulting in low Coulombic efficiency and rapid capacity decay. 2 The Coulombic efficiency of the electrode gradually decreases, and the capacity fluctuates dramatically with cycles.
[0003] Molybdenum oxide (MoOx) has metal-like conductivity and high theoretical lithium insertion capacity, and is an ideal electrochemical electrode material. However, its cycle performance is poor and it is not yet commercially available. Titanium nitride has good conductivity and mechanical stability, and is a new and promising electrode material. Titanium nitride has been widely used in photosensitive solar cells, fuel cells, and supercapacitors, but its reversible insertion / deinsertion performance for lithium ions is average. At present, although titanium nitride materials in the prior art have good conductivity and mechanical stability, their conductivity is still not ideal, and their charge and discharge cycle stability is poor. Summary of the invention
[0004] In view of the deficiencies in the prior art, the present invention provides a molybdenum oxide / titanium nitride@graphene composite material and a preparation method and application thereof. Molybdenum oxide and titanium nitride are compounded and modified with graphene to obtain a composite material that can improve the electronic conductivity of molybdenum oxide and the lithium insertion rate in the electrolyte; the compounding of titanium nitride can further improve the battery capacity, and the modification of graphene can reduce the interfacial energy and increase the affinity between materials, thereby improving the structural stability of the electrode material, effectively solving the problem of low lithium storage performance of lithium-ion batteries at low temperatures.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:
[0006] The invention discloses a method for preparing a molybdenum oxide / titanium nitride@graphene composite material, comprising the following steps:
[0007] (1) A three-electrode system is constructed with titanium nitride as the positive electrode, platinum sheet as the negative electrode, saturated calomel as the reference electrode, and ammonium molybdate as the electrolyte to obtain a MoOx / TiN composite material;
[0008] (2) The MoOx / TiN composite material is compounded with a carbon source, heated to 500-800°C in an argon atmosphere, kept warm for 0.5-3h, then heated to 900-1600°C, kept warm for 0.5-2h, cooled to room temperature, and dried to obtain a MoOx / TiN@G composite material.
[0009] Preferably, in the three-electrode system, the voltage is 0.01 to 4 V, the reaction time is 0.2 to 1.5 h, and the scan rate is 0.01 V / s to 20 V / s.
[0010] Preferably, the titanium nitride is prepared by subjecting titanium dioxide to a high temperature treatment at 450° C. to 800° C. for 0.5 h to 3 h in an ammonia atmosphere.
[0011] Preferably, the preparation process of the titanium dioxide nanotubes is: using a titanium sheet as an anode, a platinum sheet as a cathode, and an electrolyte of ammonium fluoride and ethylene glycol solution to construct a two-electrode system to obtain titanium dioxide.
[0012] Preferably, in the two-electrode system, the voltage is 0.01 to 10 V and the reaction time is 0.5 to 2 h.
[0013] Preferably, the carbon source is any one of vacuum residue, coal tar, slurry oil and asphalt.
[0014] Preferably, the mass ratio of the MoOx / TiN composite material to the carbon source is 1:3 to 5:1.
[0015] Correspondingly, a molybdenum oxide / titanium nitride@graphene composite material prepared by the above preparation method.
[0016] Correspondingly, the molybdenum oxide / titanium nitride@graphene composite material prepared by the above preparation method is used as an electrode material for lithium-ion batteries.
[0017] The present invention has the following beneficial effects:
[0018] The present invention modifies the MoOx / TiN composite material with graphene and utilizes effective chemical process means to reduce the interface energy, increase the affinity between materials, and improve the low-temperature stability of the MoOx / TiN@G composite material, thereby breaking through the key technical problem that the lithium storage performance of lithium-ion batteries at low temperatures is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1This is a transmission electron microscope photo of the MoOx / TiN@G composite material prepared in Example 1; from the photo, it can be seen that there is a graphene layer on the edge and the material has a pore structure.
[0020] Figure 2 These are nitrogen adsorption-desorption curves of the MoOx / TiN@G composite materials prepared in Example 1 and Example 2; it can be seen that the material is a porous material with micropores and mesopores.
[0021] Figure 3 The electrical conductivity diagram of the MoOx / TiN@G composite materials prepared in Examples 1 and 2 and the MoOx / TiN composite material prepared in Comparative Example 1; it can be clearly seen from the figure that the electrical conductivity of the MoOx / TiN@G composite materials prepared in Examples 1 and 2 is greater than the electrical conductivity of the MoOx / TiN prepared in Comparative Example 1.
[0022] Figure 4 The rate performance of the MoOx / TiN@G composite materials prepared in Example 1 and Example 2 assembled into a lithium-ion battery at 0°C;
[0023] Figure 5 The rate performance of the lithium-ion battery assembled from the MoOx / TiN@G composite materials prepared in Example 1 and Example 2 at -5°C;
[0024] Figure 6 The cycling performance of lithium-ion batteries assembled from the MoOx / TiN@G composite materials prepared in Example 1 and Example 2 at -8°C. DETAILED DESCRIPTION
[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0026] Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.
[0027] The present invention discloses a method for preparing a molybdenum oxide / titanium nitride@graphene composite material, the steps of which are as follows:
[0028] (1) Preparation of MoOx / TiN composite materials: Titanium sheets were degreased, polished and other pretreatments before use as anodes, platinum sheets were used as cathodes, and the electrolyte was ammonium fluoride and ethylene glycol solution (mass ratio of 1:3). A two-electrode system was constructed, the voltage was adjusted to 0.01-10 V, and the reaction time was 0.5-2 h to obtain titanium dioxide, which was washed and dried for later use.
[0029] The prepared titanium dioxide was treated at 450℃~800℃ for 0.5h~3h in an ammonia atmosphere to obtain titanium nitride. A three-electrode system was constructed with titanium nitride as the positive electrode, platinum sheet as the negative electrode, saturated calomel as the reference electrode, ammonium molybdate as the electrolyte, the voltage was regulated to 0.01~4V, the reaction time was 0.2~1.5h, and the scanning rate was 0.01V / s~20V / s to obtain MoOx / TiN composite material.
[0030] (2) Preparation of MoOx / TiN@G composite material: The MoOx / TiN composite material is compounded with a carbon source, heated to 500-800°C in an argon atmosphere, kept warm for 0.5-3 h, then heated to 900-1600°C, kept warm for 0.5-2 h, and finally cooled to room temperature, washed, and dried to obtain the MoOx / TiN@G composite material.
[0031] The carbon source is any one of vacuum residue oil, coal tar, slurry oil and asphalt. The mass ratio of the MoOx / TiN composite material to the carbon source is 1:3 to 5:1.
[0032] The present invention will be further described below in conjunction with specific embodiments.
[0033] In the following examples, the vacuum residue oil used was from Sinopec Qinhuangdao Refinery, and the contents of saturated phenol (S), aromatic phenol (A), colloid (R) and asphaltene (A) were 21.1%, 35.3%, 37.5% and 6.1%, respectively.
[0034] Example 1
[0035] The preparation steps of molybdenum oxide / titanium nitride@graphene composite material are as follows:
[0036] (1) Preparation of MoOx / TiN composite materials: Titanium sheet was used as anode after degreasing and polishing, platinum sheet was used as cathode, and the electrolyte was ammonium fluoride and ethylene glycol solution. A two-electrode system was constructed. The voltage was adjusted to 0.5 V and the reaction time was 1 h to obtain titanium dioxide, which was washed and dried for later use.
[0037] The prepared titanium dioxide was treated at 500℃ for 1.5h in an ammonia atmosphere to obtain titanium nitride. A three-electrode system was constructed with titanium nitride as the positive electrode, platinum sheet as the negative electrode, saturated calomel as the reference electrode, ammonium molybdate as the electrolyte, and the voltage was adjusted to 0.5V, the reaction time was 1h, and the scanning rate was 1V / s to obtain the MoOx / TiN composite material.
[0038] (2) Preparation of MoOx / TiN@G composite material: The MoOx / TiN composite material was compounded with liquid asphalt, heated to 500°C in an argon atmosphere, kept warm for 0.5 h, then heated to 1000°C, kept warm for 0.5 h, and finally cooled to room temperature. The MoOx / TiN@G composite material was obtained after washing and drying.
[0039] The specific surface area of the MoOx / TiN@G composite material prepared in Example 1 is 500 m 2 / g, pore volume 1.2cm 3 / g. Its transmission electron microscope image is as follows Figure 1 As shown, it can be seen from the figure that there is a graphene layer on the edge and the material has a pore structure.
[0040] Example 2
[0041] The preparation steps of molybdenum oxide / titanium nitride@graphene composite material are as follows:
[0042] (1) Preparation of MoOx / TiN composite materials: Titanium sheets were used as anodes after degreasing and polishing, and platinum sheets were used as cathodes. The electrolyte was ammonium fluoride and ethylene glycol solution. A two-electrode system was constructed. The voltage was adjusted to 1 V and the reaction time was 1.5 h to obtain titanium dioxide, which was washed and dried for later use.
[0043] The prepared titanium dioxide was treated at 500℃ for 1.5h in an ammonia atmosphere to obtain titanium nitride. A three-electrode system was constructed with titanium nitride as the positive electrode, platinum sheet as the negative electrode, saturated calomel as the reference electrode, ammonium molybdate as the electrolyte, and the voltage was regulated to 1V, the reaction time was 1.2h, and the scanning rate was 0.5V / s to obtain the MoOx / TiN composite material.
[0044] (2) Preparation of MoOx / TiN@G composite material: The MoOx / TiN composite material was compounded with liquid asphalt, heated to 550°C in an argon atmosphere, kept warm for 1 h, then heated to 1200°C, kept warm for 1 h, and finally cooled to room temperature. The MoOx / TiN@G composite material was obtained after washing and drying.
[0045] The specific surface area of the MoOx / TiN@G composite material prepared in Example 2 is 600 m 2 / g, pore volume 1.5cm 3 / g.
[0046] The nitrogen adsorption-desorption curves of the MoOx / TiN@G composite materials prepared in Example 1 and Example 2 are shown in FIG. Figure 2 As shown in the figure, it can be seen that the prepared composite material is a porous material with micropores and mesopores.
[0047] Comparative Example 1
[0048] The preparation steps of MoOx / TiN composite material are as follows:
[0049] After degreasing, polishing and other pretreatments, the titanium sheet was used as the anode, the platinum sheet was used as the cathode, the electrolyte was ammonium fluoride and ethylene glycol solution, a two-electrode system was constructed, the voltage was adjusted to 1.2V, the reaction time was 0.6h, titanium dioxide was obtained, and it was washed and dried for use.
[0050] The prepared titanium dioxide was treated at 600℃ for 1.5h in an ammonia atmosphere to obtain titanium nitride. A three-electrode system was constructed with titanium nitride as the positive electrode, platinum sheet as the negative electrode, saturated calomel as the reference electrode, ammonium molybdate as the electrolyte, and the voltage was adjusted to 0.5V, the reaction time was 0.6h, and the scanning rate was 0.3V / s to obtain the MoOx / TiN composite material.
[0051] The specific surface area of the MoOx / TiN composite material prepared in Comparative Example 1 is 160 m 2 / g, pore volume 0.8cm 3 / g.
[0052] The electrical conductivity of the MoOx / TiN@G composite materials prepared in Example 1 and Example 2 and the MoOx / TiN composite material prepared in Comparative Example 1 is as follows: Figure 3 As shown, it can be clearly seen from the figure that the electrical conductivity of the MoOx / TiN@G composite materials prepared in Example 1 and Example 2 is greater than the electrical conductivity of the MoOx / TiN composite material prepared in Comparative Example 1.
[0053] Example 3 Assembling a lithium-ion battery
[0054] The MoOx / TiN@G composite material prepared in Example 1 and Example 2, conductive carbon black, and polyvinylidene fluoride (binder PVDF) were mixed into a slurry in a mass ratio of 7:1:2, and coated on a copper foil to make a working electrode. The lithium sheet was used as the counter electrode, and the electrolyte was 1 mol / L LiPF 6 The electrolyte (EC:EMC=3:7, 2% VC) was assembled into a lithium-ion battery and its lithium storage performance was tested at an operating voltage of 0.1V to 3.0V. The test results are shown in Figure 4-Figure 6 .
[0055] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.
Claims
1. A method for preparing a molybdenum oxide / titanium nitride@graphene composite material, characterized in that: The following steps are involved: (1) A three-electrode system is constructed with titanium nitride as the positive electrode, platinum sheet as the negative electrode, saturated calomel as the reference electrode, and ammonium molybdate as the electrolyte to obtain a MoOx / TiN composite material; (2) The MoOx / TiN composite material is compounded with a carbon source, heated to 500-800°C in an argon atmosphere, kept warm for 0.5-3h, then heated to 900-1600°C, kept warm for 0.5-2h, cooled to room temperature, and dried to obtain a MoOx / TiN@G composite material.
2. The preparation method according to claim 1, characterized in that: In the three-electrode system, the voltage is 0.01 to 4 V, the reaction time is 0.2 to 1.5 h, and the scan rate is 0.01 V / s to 20 V / s.
3. The preparation method according to claim 1, characterized in that: The titanium nitride preparation process is as follows: titanium dioxide is treated at a high temperature of 450° C. to 800° C. for 0.5 h to 3 h in an ammonia atmosphere to obtain the titanium nitride.
4. The preparation method according to claim 3, characterized in that: The preparation process of the titanium dioxide nanotubes is as follows: a titanium sheet is used as an anode, a platinum sheet is used as a cathode, and an electrolyte is ammonium fluoride and ethylene glycol solution, so as to construct a two-electrode system to obtain titanium dioxide.
5. The preparation method according to claim 4, characterized in that: In the two-electrode system, the voltage is 0.01 to 10 V and the reaction time is 0.5 to 2 hours.
6. The preparation method according to claim 1, characterized in that: The carbon source is any one of vacuum residue oil, coal tar, slurry oil and asphalt.
7. The preparation method according to claim 1 or 7, characterized in that: The mass ratio of the MoOx / TiN composite material to the carbon source is 1:3 to 5:
1.
8. A molybdenum oxide / titanium nitride@graphene composite material prepared by the preparation method according to any one of claims 1 to 7.
9. Use of the molybdenum oxide / titanium nitride@graphene composite material prepared by the preparation method according to any one of claims 1 to 7 as an electrode material for a lithium ion battery.