Two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material and preparation method thereof

Abstract

This invention discloses a two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material and its preparation method, wherein octanediamine molecules are inserted into layered nickel-doped titanate (H2O) molecules. 0.8 Ti 1.6 Ni 0.4 TiO2 nanosheets are intercalated, and then, through spatially confined low-temperature pre-carbonization, high-temperature carbonization, and thermal nitriding reactions, the intercalated octyl diamine molecules are carbonized into two-dimensional nitrogen-doped carbon sheets. Simultaneously, TiO2 is in-situ nitrided into two-dimensional oxygen-doped titanium nitride (TiNO2). x Two-dimensional TiNO3 composites were prepared by layer-by-layer synthesis at the nanoscale. x / NC composite electrode material. Carbon intercalation in the composite material effectively improves the longitudinal conductivity of two-dimensional oxygen-doped titanium nitride, enhancing the material's electrochemical utilization, volumetric specific capacity, and electrochemical stability. By controlling the nitriding time to regulate the nitrogen-oxygen ratio in the nitride, the pseudocapacitance in the material can be adjusted, proposing a method to improve pseudocapacitive energy storage and providing guidance for the design of transition metal nitride capacitor materials.

Description

Technical Field

[0001] This invention belongs to the field of electrode material technology, specifically relating to a two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material and its preparation method. Background Technology

[0002] Supercapacitors are a novel type of electrochemical energy storage device that falls between traditional capacitors and batteries. They possess advantages such as fast charge / discharge speeds, long cycle life, and high safety, and have garnered widespread attention in the energy storage field. However, current supercapacitors generally suffer from low energy density, particularly low volumetric energy density, hindering their large-scale application. Electrode materials, as the core component of supercapacitors, determine their energy storage performance. Therefore, developing novel electrode materials that combine high conductivity, high density, and high specific capacitance is crucial for developing supercapacitors with high volumetric energy density and high power density. Transition metal nitrides (NNOx) exhibit high electrochemical capacity and good chemical stability, making them a promising electrode material for supercapacitors.

[0003] Titanium nitride (TiN) possesses metal-like electrical conductivity and excellent capacitance, making it an ideal high-power capacitor material. However, current TiN solutions suffer from small specific surface area, low material utilization, and insufficient cycle stability, failing to meet practical application requirements. Researchers have proposed a series of improvement measures to enhance TiN performance, such as nanostructuring and compositing with other stable materials (e.g., carbon materials). The literature "Wang C, Zhou P, Wang ZY, et al. TiN nanosheet arrays on Ti foils for high-performance supercapacitance[J]. RSC Adv., 2018, 8: 12841." combines hydrothermal, ion exchange, and nitriding reactions to develop a simple, template-free method for directly preparing mesoporous TiN nanostructures on titanium foil. The TiN nanosheet arrays prepared on titanium foil can be directly used as electrodes, with close contact between TiN and Ti foil, eliminating the need for additional conductive agents and binders, making it a good capacitor material, although its capacitance is relatively low. The literature “Qi H, Yick S, Francis O, et al. Nanohybrid TiN / Vertical graphene for high-performance supercapacitor applications[J]. Energy Storage Materials, 2020, 26:138.” describes the deposition of TiN particles prepared by the transfer arc method onto vertical graphene nanosheets (VG) to form a TiN / VG composite electrode. The titanium nitride prepared by this method has a higher areal specific capacity than commercial titanium nitride deposited on vertical graphene; however, the preparation method is complex and requires strict experimental conditions. The literature “Yao Bin, Li MY, Zhang J, et al. TiN Paper for Ultrafast-Charging Supercapacitors[J]. Nano-Micro Lett. 2020, 12:3.” designs a porous TiN paper composed of nanoribbons with abundant pore structure for use as an electrode material for fast-charging supercapacitors, but this material has poor cycling stability in acidic and alkaline electrolytes. Summary of the Invention

[0004] This invention is proposed to overcome the shortcomings of the prior art, and its purpose is to provide a composite two-dimensional titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material composed of two-dimensional oxygen-doped titanium nitride and two-dimensional nitrogen-doped carbon layers, and its preparation method.

[0005] This invention is achieved through the following technical solution:

[0006] A method for preparing a two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material, characterized by comprising the following steps:

[0007] (i) Doping layered nickel with titanate (H) 0.8 Ti 1.6 Ni 0.4 O4) was dispersed in an octanediamine solution and stirred at room temperature for 12-48 h to introduce octanediamine into the interlayer of nickel-doped titanate. After the reaction was completed, the mixture was filtered, and the separated solid components were washed with deionized water and then dried naturally to obtain octanediamine-intercalated nickel-doped titanate.

[0008] (ii) The octyldiamine-intercalated nickel-doped titanate (octyldiamine / HTNO) prepared in step (i) is converted in situ to nitride products (Ni / two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon) through a spatially confined reaction; the spatially confined reaction includes low-temperature pre-carbonization and high-temperature carbonization in argon gas, followed by a high-temperature thermal nitride reaction with ammonia gas when the nitride temperature is reached; during this process, the intercalated octyldiamine is converted into two-dimensional nitrogen-doped carbon nanosheets, while TiO2 is in situ nitrided to two-dimensional oxygen-doped titanium nitride (TiNO). x );

[0009] (iii) The nitride product prepared in step (ii) is soaked in 1M HCl for 12 hours to remove the metallic nickel formed during the high-temperature reduction process. Then, it is washed with water until neutral, filtered, and dried to obtain the nanoscale layer-by-layer composite two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material (TiNO3). x / NC).

[0010] In the above technical solution, the layered nickel-doped titanate is prepared using the molten salt method described in the literature (Journal of Solid State Chemistry, 1980, 32, 289-296). The introduction of nickel is beneficial to the formation of the layered structure, which has a size of 5-10 μm. The specific elemental composition of the layered nickel-doped titanate is H. 0.8 Ti 1.6 Ni 0.4 O4.

[0011] In the above technical solution, the molar ratio of the layered nickel-doped titanate to octanediamine is 1:1.

[0012] In the above technical solution, the concentration of the aqueous solution of octanediamine is 8-10 mg / ml.

[0013] In the above technical solution, the low-temperature pre-carbonization is carried out under an inert atmosphere (Ar), the low-temperature pre-carbonization temperature is 300℃, the heating rate is 2-5℃ / min, the inert atmosphere flow rate is 20-100sccm, and the carbonization time is 1-6h; the preferred conditions are a heating rate of 3℃ / min, an inert atmosphere flow rate of 30sccm, and a carbonization time of 3-6h.

[0014] In the above technical solution, the high-temperature carbonization is carried out under an inert atmosphere (Ar), the high-temperature carbonization temperature is 500℃, the heating rate is 2-10℃ / min, the inert atmosphere flow rate is 20-200sccm, and the carbonization time is 3-6h; the preferred conditions are a heating rate of 3℃ / min, an inert atmosphere flow rate of 30sccm, and a carbonization time of 3h.

[0015] In the above technical solution, the thermal nitriding reaction is carried out in an ammonia atmosphere, the thermal nitriding temperature is 750℃, the heating rate is 5-10℃ / min, the ammonia flow rate is 50-150 sccm, and the nitriding time is 1-9h; the preferred conditions are a heating rate of 5℃ / min, an ammonia flow rate of 80 sccm, and a nitriding time of 1-7h.

[0016] A two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material, wherein the electrode material is composed of two-dimensional TiNO3. x The ordered stacked structure formed by alternating layers of nitrogen-doped carbon at the nanoscale, with nitrogen-doped carbon inserted into two-dimensional TiNO3. x Stable carbon and TiNO are formed between the layers. x interface.

[0017] In the above technical solution, both the oxygen-doped titanium nitride and the nitrogen-doped carbon are two-dimensional sheet structures, with the sheet size being approximately 10 μm; the surface of the oxygen-doped titanium nitride has abundant mesoporous structures, and its specific surface area is 40.0-130.0 m². 2 / g, with a pore volume of 0.15-0.35cc / g; the nitrogen-doped carbon has a complete two-dimensional structure, avoiding the stacking of oxygen-doped titanium nitride nanosheets, effectively improving the longitudinal conductivity of two-dimensional oxygen-doped titanium nitride, and improving the electrochemical utilization rate, volumetric capacity and stability of the material during electrochemical testing.

[0018] In the above technical solution, the specific capacity of the two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material in acidic electrolyte is determined by the nitrogen-oxygen ratio and is positively correlated with the content of the N-Ti-O component.

[0019] In the above technical solution, the two-dimensional oxygen-doped titanium nitride has a crystal structure similar to titanium nitride, and the total nitrogen-oxygen ratio is 0.2-1.2 under different nitriding times, preferably 0.2, 0.6, 0.9 or 1.2; the performance is optimal when the nitrogen-oxygen ratio is 0.9 (nitriding time is 5h).

[0020] A pseudocapacitive energy storage method for a two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material, derived from H in an acidic electrolyte. + The interaction with N-Ti-O, combined with in-situ infrared characterization, indicates that H + Insertion and extraction within materials provide pseudocapacitive energy storage.

[0021] An application of a two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material for energy storage devices such as aqueous pseudocapacitive energy storage, lithium-ion batteries, or lithium-ion capacitors.

[0022] The principle of this invention:

[0023] This invention uses octyldiamine intercalated nickel-doped titanate (H) 0.8 Ti 1.6 Ni 0.4 Using O4 as a precursor, in-situ carbonization and nitriding reactions were carried out to obtain a composite material (2D TiNO3) of two-dimensional oxygen-doped titanium nitride and two-dimensional nitrogen-doped carbon sheets stacked at the nanoscale through a spatial confinement effect. x / NC). The pre-carbonization process stabilizes the octanediamine molecule, followed by increased temperature carbonization to form a stable carbon layer, preventing the violent reaction during high-temperature nitriding. During nitriding in an ammonia atmosphere, adjusting the nitriding time yields two-dimensional TiNO3 with different nitrogen-oxygen ratios. x The performance test of the / NC composite electrode material in 0.5M H2SO4 revealed the variation of pseudocapacitance under different nitrogen-oxygen ratios, and its capacity was related to the content of N-Ti-O. Combined with in-situ infrared spectroscopy, it was found that the pseudocapacitance originated from H. + In two-dimensional TiNO x Adsorption / deintercalation in materials.

[0024] The beneficial effects of this invention are:

[0025] This invention provides a two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material and its preparation method. During the preparation process, two-dimensional TiO2 is controllably converted into two-dimensional mesoporous TiNO. x Furthermore, the two-dimensional carbon sheets intercalate with the carbon layer to form an ordered layered composite structure, improving the space utilization of the electrode material. The large specific surface area and porosity of the two-dimensional mesoporous nanosheets endow the material with a large volumetric specific capacity and excellent charge-discharge rate characteristics. The two-dimensional carbon sheets are inserted into the two-dimensional mesoporous TiNO₃ in the electrode material. x Stable carbon and TiNO are formed between the layers. x The interface not only enhances TiNO x The structural stability and long-range conductivity of TiNO are beneficial for rapid electron transport, and also for TiNO x It has a protective effect and improves TiNO xThe electrochemical stability of TiNO3 was determined by adjusting the nitrogen-oxygen ratio; different TiNO3 values ​​were obtained. x The capacity is positively correlated with the content of N-Ti-O components in the material, and the performance is optimal when the nitrogen-oxygen ratio is 0.9, providing guidance for the design of two-dimensional metal nitrides with high volumetric capacity. In-situ characterization revealed the pseudocapacitive energy storage mechanism of two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon in sulfuric acid electrolyte as H + Embedding and extraction within the material. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the reaction mechanism of the preparation method of the two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material of the present invention;

[0027] Figure 2 These are X-ray diffraction patterns at different stages of the preparation process in Example 1 of this invention;

[0028] Figure 3 The Raman spectrum of the final product prepared in Example 1 of this invention;

[0029] Figure 4 The image shown is a scanning electron microscope (SEM) image of the final product prepared in Example 1 of this invention.

[0030] Figure 5 The image shown is a transmission electron microscope (TEM) image of the final product prepared in Example 1 of this invention.

[0031] Figure 6 The thermal analysis curve of the final product obtained in Example 1 of this invention;

[0032] Figure 7 The X-ray diffraction patterns of the final products prepared in Examples 1, 2, 3 and 4 of this invention are shown.

[0033] Figure 8 These are scanning electron microscope images of the final products prepared in Examples 2, 3, and 4 of this invention;

[0034] Figure 9 The electrochemical performance diagrams of the final products prepared in Examples 1, 2, 3 and 4 of this invention, i.e., under different nitrogen-oxygen ratios, in H2SO4 electrolyte, and the relationship between the performance and the N-Ti-O content of the components are shown.

[0035] Figure 10 The CV curves of the final product prepared in different electrolytes in Example 1 of this invention are shown below.

[0036] Figure 11 The in-situ mass change detection (EQCM) of the final product prepared in Example 1 of the present invention during charging and discharging in H2SO4 electrolyte;

[0037] Figure 12The in-situ infrared test results of the final product prepared in H2SO4 electrolyte in Example 1 of this invention;

[0038] Figure 13 The image shows a scanning electron microscope (SEM) image of the final product prepared in Comparative Example 1 of this invention.

[0039] Figure 14 This is a performance comparison chart of the final products prepared in Example 1 and Comparative Example 1 of the present invention.

[0040] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0042] In the following examples, the layered nickel-doped titanate used was prepared by the molten salt method described in the literature (Journal of solid state chemistry, 1980, 32, 289-296), and its size was 5-10 μm.

[0043] Example 1

[0044] A two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material, the synthesis reaction mechanism of which is as follows: Figure 1 As shown, the preparation method specifically includes the following steps:

[0045] (i) 100 mg of layered nickel-doped titanate was dispersed in 10 mL of aqueous solution containing 90 mg of octanediamine. The mixture was stirred continuously at room temperature for 24 h to carry out the room temperature intercalation reaction. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried naturally to obtain octanediamine-intercalated nickel-doped titanate.

[0046] (ii) The nickel-doped titanate with octanediamine intercalated in step (i) was pre-carbonized at low temperature to 300℃ for 3h in an argon atmosphere at a heating rate of 3℃ / min, and then heated to 500℃ for high-temperature carbonization reaction for 3h at a heating rate of 3℃ / min. Subsequently, when the temperature was raised to 750℃, ammonia was switched to high-temperature nitriding for 5h to obtain the nitrided product.

[0047] (iii) The nitride product prepared in step (ii) is soaked in 1M HCl for 12 hours to remove the metallic nickel formed during high-temperature calcination. It is then washed with water until neutral, filtered, and dried to obtain two-dimensional TiNO. x / NC-5h.

[0048] The products at different preparation stages were analyzed by XRD, and the X-ray diffraction patterns are as follows: Figure 2 As shown in the figure, the XRD results indicate that octyldiamine was successfully inserted into the interlayer of layered titanate, and after nitridation, TiNO was obtained. x / NC-5h. By Figure 3 The Raman spectra show that the final prepared electrode material has obvious D and G peaks, indicating that carbon was successfully introduced into TiNO. x middle.

[0049] Meanwhile, the morphology of the product was analyzed by SEM and TEM. Figure 4 The scanning electron microscope images show that the obtained product is about 10 μm in size. Figure 5 Transmission electron microscopy images, combined with Figure 4 The scanning images show that the nitriding process used in this invention does not damage the overall morphology of the composite material. TiNO x Both TiNO and C are two-dimensional structures, with the two-dimensional TiNO being the most common. x The film contains abundant mesopores.

[0050] Thermal analysis was performed on the product obtained in this embodiment, and the results are as follows: Figure 6 As shown, the carbon content in the product is 15.2%.

[0051] Example 2

[0052] In this embodiment, except for the high-temperature nitriding time (1h) in step (ii), the rest of the preparation methods are the same as in Example 1.

[0053] A two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material, the synthesis reaction mechanism of which is as follows: Figure 1 As shown, the preparation method specifically includes the following steps:

[0054] (i) 100 mg of layered nickel-doped titanate was dispersed in 10 mL of aqueous solution containing 90 mg of octanediamine. The mixture was stirred continuously at room temperature for 24 h to carry out the room temperature intercalation reaction. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried naturally to obtain octanediamine-intercalated nickel-doped titanate.

[0055] (ii) The nickel-doped titanate with octanediamine intercalated in step (i) was pre-carbonized at low temperature to 300℃ for 3h in an argon atmosphere at a heating rate of 3℃ / min, and then heated to 500℃ for high-temperature carbonization reaction for 3h at a heating rate of 3℃ / min. Subsequently, when the temperature was raised to 750℃, ammonia was switched to high-temperature nitriding for 1h to obtain the nitrided product.

[0056] (iii) The nitride product prepared in step (ii) is soaked in 1M HCl for 12 hours to remove the metallic nickel formed during high-temperature calcination. It is then washed with water until neutral, filtered, and dried to obtain two-dimensional TiNO. x / NC-1h.

[0057] Example 3

[0058] In this embodiment, except for the high-temperature nitriding time (3h) in step (ii), the rest of the preparation methods are the same as in Example 1.

[0059] A two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material, the synthesis reaction mechanism of which is as follows: Figure 1 As shown, the preparation method specifically includes the following steps:

[0060] (i) 100 mg of layered nickel-doped titanate was dispersed in 10 mL of aqueous solution containing 90 mg of octanediamine. The mixture was stirred continuously at room temperature for 24 h to carry out the room temperature intercalation reaction. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried naturally to obtain octanediamine-intercalated nickel-doped titanate.

[0061] (ii) The nickel-doped titanate with octanediamine intercalated in step (i) was pre-carbonized at low temperature to 300℃ for 3h in an argon atmosphere at a heating rate of 3℃ / min, and then heated to 500℃ for high-temperature carbonization reaction for 3h at a heating rate of 3℃ / min. Subsequently, when the temperature was raised to 750℃, ammonia was switched to high-temperature nitriding for 3h to obtain the nitrided product.

[0062] (iii) The nitride product prepared in step (ii) is soaked in 1M HCl for 12 hours to remove the metallic nickel formed during high-temperature calcination. It is then washed with water until neutral, filtered, and dried to obtain two-dimensional TiNO. x / NC-3h.

[0063] Example 4

[0064] In this embodiment, except for the high-temperature nitriding time (7h) in step (ii), the rest of the preparation methods are the same as in Example 1.

[0065] A two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material, the synthesis reaction mechanism of which is as follows: Figure 1 As shown, the preparation method specifically includes the following steps:

[0066] (i) 100 mg of layered nickel-doped titanate was dispersed in 10 mL of aqueous solution containing 90 mg of octanediamine. The mixture was stirred continuously at room temperature for 24 h to carry out the room temperature intercalation reaction. After the reaction was completed, the mixture was filtered, washed with deionized water, and dried naturally to obtain octanediamine-intercalated nickel-doped titanate.

[0067] (ii) The nickel-doped titanate with octanediamine intercalated in step (i) was pre-carbonized at low temperature to 300℃ for 3h in an argon atmosphere at a heating rate of 3℃ / min, and then heated to 500℃ for high-temperature carbonization reaction for 3h at a heating rate of 3℃ / min. Subsequently, when the temperature was raised to 750℃, ammonia was switched to high-temperature nitriding for 7h to obtain the nitrided product.

[0068] (iii) The nitride product prepared in step (ii) is soaked in 1M HCl for 12 hours to remove the metallic nickel formed during high-temperature calcination. It is then washed with water until neutral, filtered, and dried to obtain two-dimensional TiNO. x / NC-7h.

[0069] The products prepared in Examples 1-4 were analyzed and compared:

[0070] pass Figure 7 The X-ray diffraction pattern shown indicates that as the nitriding time increases, TiO2 gradually transforms into a form close to TiN.

[0071] pass Figure 8 The scanning electron microscope images shown indicate that the morphology remains basically consistent under different nitriding times (nitrogen-oxygen ratios).

[0072] The percentages of Ti-O, Ti-N, and N-Ti-O components and their corresponding nitrogen-oxygen ratios in Examples 1-4 were fitted using XPS test results. The results are shown in Table 1 below. It can be seen that as the nitriding time (nitrogen-oxygen ratio) is adjusted, the Ti-O content gradually decreases, while the Ti-N content is the opposite. The N-Ti-O content first increases and then decreases, and the content is highest when the nitrogen-oxygen ratio is 0.9.

[0073]

[0074] pass Figure 9 The electrochemical performance graphs of the final products prepared in H2SO4 electrolyte in Examples 1, 2, 3 and 4 show that their capacity is positively correlated with the content of N-Ti-O, and the highest content and best performance are achieved when the nitrogen-oxygen ratio is 0.9.

[0075] pass Figure 10 The CV curves of the final product prepared in Example 1 in different electrolytes show that, by comparing its performance with that of the inactive electrolyte [(C2H5)4N]BF4, it can be seen that in H2SO4, in addition to the double-layer capacitance, there is also pseudocapacitance, and it is H2SO4... + It participates in electrochemical reactions to provide pseudocapacitance.

[0076] pass Figure 11 The final product prepared in Example 1, as shown in the EQCM analysis in H2SO4 electrolyte, exhibits a decrease in mass during charging, indicating the departure of cations, i.e., H+. + During deintercalation, the opposite occurs during discharge, proving that H + Participated in providing pseudocapacitors.

[0077] pass Figure 12 The in-situ infrared spectroscopy results of the final product prepared in Example 1 in H2SO4 electrolyte show that a blue shift occurs during charging. +Intercalation and deintercalation increase the interlayer spacing, compressing the crystal structure and causing the bond length to shorten, resulting in a blue shift of the infrared peak. The opposite occurs during discharge.

[0078] To further compare the significant effects brought about by the introduction of a carbon layer into the composite electrode material of the present invention, Comparative Example 1 was designed.

[0079] Comparative Example 1

[0080] An oxygen-doped titanium nitride electrode material, the specific preparation method of which includes the following steps:

[0081] (i) 200 mg of layered nickel-doped titanate was directly heated to 750 °C at a heating rate of 5 °C / min and nitrided for 5 h to obtain the nitrided product.

[0082] (ii) The nitriding product was acid-washed, water-washed until neutral, filtered, and dried to obtain TiNO. x -5h.

[0083] In the comparative example, pure layered nickel-doped titanate was subjected to the same thermal nitriding treatment conditions as in Example 1. Figure 13 The scanning electron microscope image of the product in Comparative Example 1 shown indicates that TiNO3... x The sheets sintered together and broke apart, further demonstrating that the introduction of the carbon layer effectively reduced the TiNO₃ content during the nitriding process. x The sintering of the sheets increases the specific surface area of ​​the material, providing more electrochemical active sites; simultaneously, through Figure 14 The graph shown is a performance comparison of the final products prepared in Example 1 and Comparative 1 of the present invention. It can be seen that the introduction of the carbon layer significantly improves its volumetric capacity and electrochemical stability.

[0084] This invention first inserts octanediamine molecules into pre-synthesized layered nickel-doped titanate (H2O) via an acid-base reaction. 0.8 Ti 1.6 Ni 0.4 By intercalating octyldiamine (OCD) nanosheets into the O4 nanosheets, Ni-TiO2 nanosheets were prepared. Then, through a spatially confined thermal nitriding reaction, the intercalated OCD molecules were carbonized into two-dimensional nitrogen-doped carbon sheets, while the two-dimensional TiO2 was in situ nitrided into two-dimensional TiNO3. x Two-dimensional TiNO3 composites can be prepared in a controlled manner at the nanoscale, layer-by-layer composite. x This invention utilizes NC hybrid electrode materials to investigate the influence of the nitrogen-oxygen ratio in nitrides on pseudocapacitance by controlling the nitriding time, proposing the corresponding energy storage mechanism and an electrochemical model for pseudocapacitance generation. The composite material obtained in this invention can effectively improve the specific capacitance of layered nitrides, achieving high volumetric specific capacitance and excellent stability. The elucidation of the pseudocapacitive energy storage mechanism provides guidance for nitride design, making it a promising electrode material for supercapacitors.

[0085] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material, characterized in that: Includes the following steps: (i) Disperse layered nickel-doped titanate in an octanediamine solution, and insert octanediamine into the interlayer of nickel-doped titanate to obtain octanediamine-intercalated nickel-doped titanate; (ii) The octanediamine-intercalated nickel-doped titanate prepared in step (i) is subjected to low-temperature pre-carbonization, high-temperature carbonization and thermal nitriding reactions; (iii) The product prepared in step (ii) is acid-washed, water-washed until neutral, filtered, and dried to obtain the two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material. 2.The method of claim 1, wherein: The layered nickel-doped titanate was synthesized by molten salt method and has a size of 5-10 μm; the molar ratio of the layered nickel-doped titanate to octanediamine is 1:1; step (i) is carried out under stirring at room temperature for 12-48 h; the octanediamine solution is an aqueous solution of octanediamine with a concentration of 8-10 mg / mL. 3.The method of claim 1, wherein: The low-temperature pre-carbonization is carried out under an inert atmosphere, with a pre-carbonization temperature of 300℃, a heating rate of 2-5℃ / min, an inert atmosphere flow rate of 20-100 sccm, and a carbonization time of 1-6 h; the high-temperature carbonization is carried out under an inert atmosphere, with a high-temperature carbonization temperature of 500℃, a heating rate of 2-10℃ / min, an inert atmosphere flow rate of 20-200 sccm, and a carbonization time of 3-6 h; the thermal nitriding is carried out under an ammonia atmosphere, with a nitriding temperature of 750℃, a heating rate of 5-10℃ / min, an ammonia flow rate of 50-200 sccm, and a nitriding time of 1-9 h.

4. A two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material, characterized in that: Prepared by the method described in any one of claims 1 to 3.

5. A two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material prepared by the method according to any one of claims 1 to 3, characterized in that: The electrode material is made of two-dimensional TiNO. x It is formed by layering nitrogen-doped carbon, with nitrogen-doped carbon inserted between oxygen-doped titanium nitride layers. 6.The two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material of claim 5, wherein: TiNO x Both TiNO3 and nitrogen-doped carbon have two-dimensional sheet structures, with sheet sizes of 5-10 μm; x The surface has a mesoporous structure, with a specific surface area of ​​40.0-130.0 m². 2 / g, with a pore volume of 0.15-0.35cc / g; the nitrogen-doped carbon has a complete structure. 7.The two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material of claim 5, wherein: The volumetric specific capacity of the composite electrode material in the electrolyte is determined by the nitrogen-oxygen ratio, and its value is positively correlated with the content of the N-Ti-O component. 8.The two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material of claim 7, wherein: The total nitrogen-oxygen ratio in the two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material is 0.2-1.

2.

9. A method for pseudocapacitive energy storage of a two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material prepared by the method according to any one of claims 1 to 3, characterized in that: By utilizing H + The pseudo-capacitive energy storage is realized by the interaction of N-Ti-O in the composite electrode material.

10. The use of a two-dimensional oxygen-doped titanium nitride / two-dimensional nitrogen-doped carbon composite electrode material prepared by the method of any one of claims 1 to 3, characterized in that: Used for water-based pseudocapacitive energy storage, lithium-ion batteries, or lithium-ion capacitors.

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