A three-dimensional lithiophilic carbon nanotube material, its preparation method, and its applications

Abstract

This invention relates to a three-dimensional lithiophilic carbon nanotube material, its preparation method, and its applications. The aim is to provide a simple and high-performance method for large-scale preparation of three-dimensional lithiophilic carbon nanotubes. The preparation method includes the following steps: S1, completely immersing carbon cloth in a mixed solution of concentrated sulfuric acid and concentrated nitric acid, stirring continuously, removing the carbon cloth, and washing off the acid solution on the surface of the carbon cloth to obtain acid-treated carbon cloth; S2, completely immersing the acid-treated carbon cloth in a transition metal salt solution, removing the carbon cloth, and drying it; S3, subjecting the carbon cloth to high-temperature annealing under a protective atmosphere to obtain porous carbon fiber cloth (PCC); S4, placing the porous carbon fiber cloth (PCC) and melamine in a crucible, and annealing at high temperature under a protective atmosphere to obtain the three-dimensional lithiophilic carbon nanotube material CNT@PCC. This invention has a simple preparation process, can be mass-produced, and enables the industrial application of lithiophilic carbon nanotube materials.

Description

Technical Field

[0001] This invention relates to the field of functional materials technology, and in particular to a three-dimensional lithiophilic carbon nanotube material, its preparation method, and its applications. Background Technology

[0002] Among various energy storage technologies, rechargeable batteries are considered one of the most reliable and practical devices. Lithium metal batteries, in particular, have attracted widespread attention from researchers, but several serious problems still limit their practical application. These problems mainly manifest as follows: (1) uneven Li plating on the negative electrode material surface leads to the formation of Li dendrites, which pierce the separator and cause short circuits; (2) significant volume changes of Li during electroplating / stripping, severely affecting the cycle life of lithium metal batteries; and (3) continuous side reactions between lithium and the electrolyte, along with the large-scale consumption of Li, result in dead lithium and damage to the SEI film, leading to irreversible consumption of a large amount of lithium. Therefore, finding a suitable method to slow down the growth of lithium dendrites and improve the cycle life of batteries is urgently needed.

[0003] Researchers have made significant efforts in modifying lithium metal anodes. These efforts include constructing conductive frameworks or modifying current collectors to enhance their affinity for lithium. + Uniform distribution at the interface can suppress the formation of lithium dendrites. In recent years, porous copper, foamed nickel, carbon, and their derivatives have been extensively studied. Carbon materials have stood out due to their strong feasibility in improving the electrodeposition behavior of lithium metal anodes, among which carbon nanotubes are widely used due to their light weight, good stability, and high conductivity. However, the weak and uneven distribution of lithium ions between the material and the lithium ions leads to the possibility of lithium dendrite growth; another key issue is the need to add catalysts to catalyze the growth of carbon nanotubes. Therefore, there is an urgent need to develop a simple method to prepare lithium-affinity carbon nanotube-based materials to obtain high-capacity lithium metal battery anodes. Summary of the Invention

[0004] Therefore, it is necessary to address the technical problems of weak and uneven bonding between existing carbon nanotube materials and lithium ions, which may lead to the growth of lithium dendrites, and the need to add catalysts to catalyze the growth of carbon nanotubes during the preparation of existing carbon nanotube materials. The aim is to provide a three-dimensional lithiophilic carbon nanotube material, its preparation method, and its applications. The purpose is to provide a simple and high-performance method for the large-scale preparation of three-dimensional lithiophilic carbon nanotubes to solve the problems of unlimited lithium dendrite growth and low coulombic efficiency.

[0005] This invention provides a method for preparing three-dimensional lithiophilic carbon nanotube materials, comprising the following steps:

[0006] S1. Completely immerse the carbon cloth in a mixed solution of concentrated sulfuric acid and concentrated nitric acid, stir continuously, remove the carbon cloth and wash off the acid on the surface of the carbon cloth to obtain acid-treated carbon cloth.

[0007] S2. Immerse the acid-treated carbon cloth completely in the transition metal salt solution, remove the carbon cloth and dry it;

[0008] S3. Under a protective atmosphere, the carbon cloth is subjected to high-temperature annealing to obtain porous carbon fiber cloth PCC.

[0009] S4. Place porous carbon fiber cloth (PCC) and melamine in a crucible and anneal at high temperature under a protective atmosphere to obtain three-dimensional lithiophilic carbon nanotube material CNT@PCC.

[0010] In a preferred embodiment of the present invention, in step S1, the volume ratio of concentrated sulfuric acid to concentrated nitric acid is 1:1, and the temperature of the mixed solution of concentrated sulfuric acid and concentrated nitric acid is 60-80°C.

[0011] And / or, in step S1, the continuous stirring time is 1-3 hours;

[0012] And / or, in step S1, the cleaning is performed by cleaning with ethanol several times.

[0013] In a preferred embodiment of the present invention, in step S1, the temperature of the mixed solution of concentrated sulfuric acid and concentrated nitric acid is 70°C.

[0014] And / or, in step S1, the continuous stirring time is 2 hours;

[0015] And / or, in step S1, the cleaning is performed twice using ethanol.

[0016] In a preferred embodiment of the present invention, in step S2, the transition metal salt solution is Fe(NO3)3, Co(NO3)2 or Ni(NO3)2;

[0017] And / or, in step S2, the carbon cloth is placed in a transition metal salt solution for 6-12 hours;

[0018] And / or, in step S2, the drying is performed in an oven at a temperature of 60-120°C for 7-12 hours.

[0019] In a preferred embodiment of the present invention, in step S2, the transition metal salt solution is Ni(NO3)2, and the concentration of the transition metal salt solution is 1 mol L-1.

[0020] And / or, in step S2, the carbon cloth is placed in a transition metal salt solution for 6 hours;

[0021] And / or, in step S2, the drying is performed in an oven at a temperature of 60°C for 7 hours.

[0022] In a preferred embodiment of the present invention, in step S3, the high-temperature annealing treatment is performed at 700-900°C for 2-5 hours; preferably, the high-temperature annealing treatment is performed at 700-900°C for 2 hours under a nitrogen protective atmosphere.

[0023] In a preferred embodiment of the present invention, in step S4, the mass ratio of porous carbon fiber cloth (PCC) to melamine is 1:10.

[0024] In a preferred embodiment of the present invention, in step S4, the high-temperature annealing treatment is annealing at 700-900°C for 0.5-2 hours; preferably, the high-temperature annealing treatment is annealing at 700°C for 0.5 hours under a nitrogen protective atmosphere.

[0025] The present invention also proposes a three-dimensional lithiophilic carbon nanotube material, which is prepared by the aforementioned method for preparing three-dimensional lithiophilic carbon nanotube materials.

[0026] This invention also proposes an application of the aforementioned three-dimensional lithiophilic carbon nanotube material in lithium metal batteries.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. This invention utilizes a nickel-catalyzed amine salt pyrolysis method to obtain a carbon fiber composite electrode material modified with a uniformly distributed, vertically oriented carbon nanotube array. Specifically, a lithiophilic carbon nanotube array (CNT@PCC) is grown on hydrophilic carbon cloth. The self-grown CNT@PCC provides a large number of lithiophilic groups, enriching lithium nucleation sites, improving the affinity between carbon fibers and lithium, suppressing lithium dendrite formation, and enabling uniform Li adsorption on the CNT@PCC surface. Simultaneously, the carbon array structure further increases the specific surface area of ​​the negative electrode, reduces the local current density, and makes lithium deposition on the negative electrode more uniform. Furthermore, the interconnected nanotube network provides abundant channels for electron transport in the negative electrode, promoting efficient electron transport.

[0029] 2. This invention utilizes a nickel-catalyzed amine salt pyrolysis method to obtain carbon fiber composite electrode materials modified with uniformly distributed vertically oriented carbon nanotube arrays. The preparation process is simple and can be mass-produced, thus enabling the industrial application of lithiophilic carbon nanomaterials.

[0030] 3. The three-dimensional lithiophilic carbon nanotube material of this invention can be used to prepare Li@CNT@PCC composite anodes via the lithium melting method. The Li@CNT@PCC composite electrodes can be assembled into symmetrical cells, and the symmetrical cells can achieve a 2 mA / cm² performance. -2 1mAh cm-2 At this point, the hysteresis voltage is extremely small and it can cycle for over 180 hours, even when the current density increases to 5 mA cm⁻¹. -2 The battery can also cycle stably at 150mV for 80 hours. This invention aims to develop a simple and high-performance method for large-scale preparation of lithium metal anodes with three-dimensional lithiophilic carbon nanotube structures, addressing problems such as unlimited lithium dendrite growth and low coulombic efficiency. Attached Figure Description

[0031] Figure 1 This invention provides a flowchart of a method for preparing three-dimensional lithiophilic carbon nanotube materials;

[0032] Figure 2 The image shown is the SEM image of the PCC in Embodiment 1 of this invention.

[0033] Figure 3 The above are SEM images of CNT@PCC-1, CNT@PCC-2, and CNT@PCC-3 in Embodiment 2 of the present invention.

[0034] Figure 4 This is the XRD image of CNT@PCC-1 in Embodiment 2 of the present invention;

[0035] Figure 5 This is the Raman spectrum image of CNT@PCC-1 in Embodiment 2 of the present invention;

[0036] Figure 6 These are SEM images of Li@CNT@PCC and pure Li foil in Embodiment 3 of the present invention;

[0037] Figure 7 The image shown is the XRD image of Li@CNT@PCC in Embodiment 3 of the present invention.

[0038] Figure 8 The cycling performance diagrams are for the Li@CNT@PCC symmetrical cell and the pure Li foil symmetrical cell in Example 3 of the present invention.

[0039] Figure 9 For the symmetrical Li@CNT@PCC cell and the symmetrical cell made of pure Li foil in Example 3 of this invention, before cycling, after 50 cycles and after 100 cycles, at 5 mA cm⁻¹ -2 The following is an EIS spectrum;

[0040] Figure 10 This is the equivalent circuit diagram of Li@CNT@PCC in Embodiment 3 of the present invention;

[0041] Figure 11 EIS equivalent resistance fitting of the Li@CNT@PCC symmetrical cell and the pure Li foil symmetrical cell before and after cycling in Embodiment 3 of the present invention;

[0042] Figure 12 The symmetrical cell of Li@CNT@PCC and the symmetrical cell of pure Li foil in Example 3 of this invention are shown at 5 mA cm⁻¹. -2 SEM after 50 cycles;

[0043] Figure 13 The symmetrical cell of Li@CNT@PCC and the symmetrical cell of pure Li foil electrode in Example 3 of this invention are shown at 5 mA / cm. -2 SEM after 100 cycles. Detailed Implementation

[0044] This invention provides a method for preparing three-dimensional lithiophilic carbon nanotube materials. The purpose is to provide a simple and high-performance method for large-scale preparation of lithium metal anodes with three-dimensional lithiophilic carbon nanotube structures, in order to solve problems such as unlimited lithium dendrite growth and low coulombic efficiency.

[0045] Reference Figure 1 This invention provides a method for preparing three-dimensional lithiophilic carbon nanotube materials, comprising the following steps:

[0046] S1. Immerse the carbon cloth completely in a mixed solution of concentrated sulfuric acid and concentrated nitric acid at 60-80℃ (volume ratio of concentrated sulfuric acid to concentrated nitric acid is 1:1). Stir continuously for 1-3 hours, then remove the carbon cloth and wash it with deionized water and ethanol in turn to remove the acid from the surface of the carbon cloth, thus obtaining the acid-treated carbon cloth.

[0047] S2. Immerse the acid-treated carbon cloth completely in the transition metal salt solution and let it stand for 6-12 hours. Then, remove the carbon cloth and dry it in an oven at 60-120℃ for 7-12 hours.

[0048] S3. Under a protective atmosphere, the carbon cloth is annealed at 700-900℃ for 2-5 hours to obtain porous carbon fiber cloth PCC.

[0049] S4. Place porous carbon fiber cloth (PCC) and melamine in a crucible and anneal at 700-900℃ for 0.5-2 hours under a protective atmosphere to obtain three-dimensional lithiophilic carbon nanotube material CNT@PCC.

[0050] This invention utilizes a nickel-catalyzed amine salt pyrolysis method to obtain carbon fiber composite electrode materials modified with uniformly distributed vertically oriented carbon nanotube arrays. The preparation process is simple, can be mass-produced, and can realize the industrial application of lithiophilic carbon nanomaterials.

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Example 1

[0053] S1. Cut the untreated carbon cloth (hereinafter referred to as CC) into uniform sizes (1×1cm). Immerse the 1×1cm CC in a mixed solution of concentrated sulfuric acid and concentrated nitric acid at 70℃ (volume ratio of concentrated sulfuric acid to concentrated nitric acid is 1:1) and stir continuously for 2 hours. Then take out the carbon cloth and wash it with deionized water 2-3 times. After that, wash it with ethanol twice to remove excess mixed acid from the surface of the carbon cloth, and obtain the acid-treated carbon cloth.

[0054] S2. Then, completely immerse the acid-treated CC in a solution with a concentration of 1 mol / L. -1 The carbon cloth was placed in a Ni(NO3)2 solution and left to stand for 6 hours. Then it was taken out and dried in an oven at 60°C for 7 hours.

[0055] S3. Subsequently, the dried carbon cloth was annealed at 700°C for 2 hours under N2 atmosphere to obtain porous carbon fiber cloth PCC.

[0056] S4. Then, PCC and melamine are placed in a crucible at a mass ratio of 1:10 and annealed at 700°C for 0.5 h under N2 atmosphere to obtain carbon fiber material modified with uniformly distributed vertically oriented carbon nanotubes, namely three-dimensional lithiophilic carbon nanotube material CNT@PCC.

[0057] Figure 2 The scanning electron microscope image shows the morphology of PCC in this embodiment. Ni in Ni(NO3)2 under high temperature conditions of 700℃... 2+ It is reduced to metallic Ni. For example... Figure 2 As shown in Figure a, Ni nanoparticles are uniformly distributed on the surface of the carbon fiber, and the Ni particles are of uniform size. Figure 2 As shown in b, the low-resolution SEM image further demonstrates that Ni particles are uniformly distributed on the surface of each carbon fiber. These Ni particles, acting as "active sites" for the subsequent growth of carbon nanotube arrays, play a crucial role in obtaining uniformly distributed, vertically aligned carbon nanotube arrays.

[0058] Example 2

[0059] In this embodiment, to achieve the preparation of uniformly grown, neatly distributed, and vertically aligned carbon nanotubes, the optimal conditions for carbon nanotube growth were explored, and the process is as follows:

[0060] The products obtained by annealing PCC and melamine at a mass ratio of 1:10 under N2 atmosphere at 700℃ for 0.5 h, 1 h, and 2 h were named CNT@PCC-1, respectively. Figure 3 (a1-a2), CNT@PCC-2 ( Figure 3 (b1-b2), CNT@PCC-3 ( Figure 3 (c1-c2).

[0061] Please see Figure 3 As shown in b1-b2, as the annealing time increases from 0.5h to 1h, the carbon nanotubes only increase in the longitudinal dimension. When the length reaches a certain space, the carbon nanotubes of different lengths intertwine with each other, exhibiting a chaotic distribution morphology.

[0062] Please see Figure 3 From c1-c2, it can be seen that when the time continues to increase to 2 hours, due to the inability to continue growth in the longitudinal direction, local competitive growth occurs in each carbon nanotube, resulting in some carbon nanotubes becoming very thick while others show little change. This is due to the spatial effect between carbon nanotubes, the fact that uniform carbon nanotube size is beneficial for uniform charge distribution, and the influence of Li... + Considering flow uniformity, CNT@PCC-1 is an ideal current collector for lithium metal anode materials. That is, by annealing PCC and melamine at a mass ratio of 1:10 under N2 atmosphere at 700℃ for 0.5h, uniform, well-distributed, and vertically aligned carbon nanotubes can be grown.

[0063] Phase characterization of CNT@PCC-1 was performed. Figure 4 This is the XRD image of CNT@PCC-1 in this embodiment. Figure 5 This is the Raman spectrum image of CNT@PCC-1 in this embodiment. Figure 4 The diffraction peaks of Ni (JPCDS No. 03-1209) at 43.69°, 50.97°, and 74.67° correspond to the Ni (111), (200), and (220) crystal planes, respectively. The broad peak around 25° represents the diffraction peak of amorphous carbon graphite crystals, proving the presence of amorphous carbon in CNT@PCC-1. Furthermore, Raman spectroscopy further confirms the degree of graphitization of PCC@CNT (see...). Figure 5 ), 1345cm -1 and 1590cm -1 The two main peaks are characteristic Raman peaks of carbon, and are associated with the D and G peaks of carbon, respectively. d / I gThe value of (0.9) indicates that CNTs have a high degree of graphitization and electrical conductivity, which also proves that the introduction of CNTs further improves the electrical conductivity of the material and is beneficial to enhancing its lithophile properties.

[0064] Example 3

[0065] Please refer to Figure 1 In this embodiment, a Li@CNT@PCC composite anode was prepared using the CNT@PCC-1 obtained in Example 2. The process is as follows:

[0066] A 1.54 cm diameter CNT@PCC-1 carbon fiber was placed on molten Li, and its surface quickly turned silvery-white.

[0067] Figure 6 In this embodiment, Li@CNT@PCC ( Figure 6 (The illustration in section a is a picture of Li@CNT@PCC) and pure Li foil ( Figure 6 SEM image of (cd) in the middle.

[0068] from Figure 6 As can be seen in Figure 2ab, the surface of Li@CNT@PCC is very smooth and flat, and the carbon fiber network has been covered by Li, which also indicates that there are sufficient deposition sites of Li on the carbon fiber surface.

[0069] On the contrary, from Figure 6 As can be seen in the mid-CD, the surface of the pure Li foil is very rough, with irregularly stacked Li particles, resulting in obvious fractures on the entire Li foil surface. It is conceivable that if pure Li foil is used, repeated deposition / stripping processes will inevitably lead to infinite changes in lithium volume and the growth of lithium dendrites.

[0070] from Figure 6 The illustrations show that the presence of carbon nanotubes does indeed greatly enhance the lithophilicity of carbon fibers, and also confirms the formation of Li@CNT@PCC.

[0071] Next, the composition of the Li@CNT@PCC phase will be further investigated.

[0072] Phase characterization of Li@CNT@PCC was performed using X-ray diffraction spectroscopy, such as... Figure 7By comparing and analyzing the diffraction peaks, it was found that 26°, 46°, and 55° correspond to the (002), (010), and (222) planes of carbon nanotubes (JCPDS no. 75-0444), respectively. The diffraction peaks of 36°, 52°, 65°, and 77° correspond to the (110), (200), (211), and (220) planes of lithium (JCPDS no. 15-0401), respectively. The diffraction peaks of 32°, 36°, and 46° correspond to the (200) and (220) planes of Li3N (JCPDS no. 02-0301). The diffraction peaks of 32°, 36°, and 52° correspond to the (101), (110), and (200) planes of LiOH (JCPDS no. 85-0736). The presence of carbon nanotubes, Li3N, and LiOH enhances the interconnected 3D network structure and the bonding force between carbon nanotubes and lithium, thus improving the efficiency of Li... + It flows uniformly on the surface of carbon fiber.

[0073] Next, the electrochemical performance of the Li@CNT@PCC anode was investigated.

[0074] (1) First, the electrochemical cycling performance of symmetrical Li@CNT@PCC and Li batteries was studied using the constant current charge-discharge method.

[0075] Figure 8 A symmetrical cell of Li@CNT@PCC ( Figure 8 Symmetrical cells of b, d, f and pure Li foil (b, d, f) Figure 8 (a, c, e) at a deposition capacity of 1 mAh / cm³ -2 Below, the current density is 2 mA / cm². -2 3mAcm -2 5mA cm -2 The following is a long loop graph.

[0076] like Figure 8 As shown in d, at current densities of 2 mA and cm⁻¹ -2 Compared with pure Li foil electrodes, Li@CNT@PCC electrodes exhibit a stable voltage distribution and have a small hysteresis during long-term cycling.

[0077] See Figure 8 f, at a current density of 5 mA cm -2 The total deposition capacity was 1 mAh cm⁻¹. -2 At that time, the initial plating / stripping overpotential of the Li@CNT@PCC electrode was 150mV. However, the pure Li foil electrode exhibited typical unevenness, and after 45.8h, the pure Li foil cell showed a short circuit, which was caused by the uneven nucleation and deposition of Li.

[0078] Therefore, the low overpotential and good stable cycling performance are attributed to the uniform nucleation and growth of lithium induced by the carbon nanotube array, which enables Li... + Uniform flux.

[0079] (2) Electrochemical impedance spectroscopy was then used to study the electrochemical performance and interfacial dynamics of the electrode materials of the symmetrical battery before cycling, after 50 cycles, and after 100 cycles.

[0080] Figure 9 Before the loop ( Figure 9 (a) 50 cycles and 100 cycles ( Figure 9 After step b), the pure Li foil symmetric cell and the Li@CNT@PCC symmetric cell were respectively tested at 5 mA cm⁻¹. -2 The EIS spectrum below.

[0081] According to the Nyquist plot, all electrode material samples consist of circular arcs in the high-frequency region and straight lines with steep slopes in the low-frequency region. To obtain more specific resistance values ​​for each part, we performed circuit element simulations based on the impedance data. The simulated equivalent circuit diagram is shown below. Figure 10 As shown, Re represents the SEI film resistance formed spontaneously by the spontaneous reaction of lithium and electrolyte when the battery first starts working, and RCT represents the resistance of Li. + During repeated charge and discharge processes, the charge transfer resistance is represented by CPE, which represents the constant-phase element, and W1, which represents the Warburg impedance. For detailed simulation results, please refer to [link / details]. Figure 11 .

[0082] from Figure 11 The results show that the interfacial resistance of the SEI of the Li@CNT@PCC composite electrode is much smaller than that of the Li foil, both before and after 50 and 100 cycles, indicating that the SEI of the Li@CNT@PCC composite electrode is more stable than that of the Li foil, regardless of the cycling process. Furthermore, after cycling, the pure Li foil exhibits a new semi-circular structure in the high-frequency region, indicating a significant change in the lithium-electrolyte interface during repeated Li plating / stripping. Simultaneously, the RCT of the Li@CNT@PCC electrode is much smaller than that of the Li foil (8.2Ω-6.0Ω) after both 50 and 100 cycles, and the RCT value remains almost unchanged with increasing cycle count (1.9Ω-1.3Ω), indicating that the Li / Li... + Enhanced reaction kinetics and improved conductivity were observed. Furthermore, compared to Li, the interfacial resistance of Li@CNT@PCC was significantly reduced, which is consistent with the lower hysteresis voltage observed in symmetric cell experiments. These results demonstrate that the construction of a lithiophilic carbon nanotube array structure can induce more uniform adsorption of Li onto the carbon nanotube surface, showcasing the superiority of the three-dimensional structure.

[0083] (3) Next, the morphology of the electrode material after 50 cycles was characterized, such as... Figure 12 As shown. From Figure 12 In section ab, it can be observed that the surface of the Li@CNT@PCC negative electrode remains relatively smooth and flat without cracks. From Figure 12 As can be seen from the Cd, in contrast, after 50 cycles of operation, the pure Li foil symmetric cell exhibits large, irregular Li deposits with a very rough surface.

[0084] (4) Finally, the morphology of the electrode material after 100 cycles was further characterized, such as... Figure 13 As shown. From Figure 13 As shown in Figure ab, it can be observed that the surface of the Li@CNT@PCC anode remains smooth and crack-free with increasing cycle count. Furthermore, from... Figure 13 In the case of Cd, the surface of pure Li foil was found to be very rough with many pores of varying sizes, indicating that the battery volume increases during cycling, corresponding to the increase in hysteresis voltage with increasing cycle number in symmetrical cells. Conversely, the hysteresis voltage of Li@CNT@PCC remained stable with increasing cycle number, further demonstrating that it is feasible to improve the electrochemical performance of lithium metal anodes through structural modulation.

[0085] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0086] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a three-dimensional lithiophilic carbon nanotube material, characterized in that, Includes the following steps: S1. Completely immerse the carbon cloth in a mixed solution of concentrated sulfuric acid and concentrated nitric acid, stir continuously, remove the carbon cloth and wash off the acid on the surface of the carbon cloth to obtain acid-treated carbon cloth. S2. Completely immerse the acid-treated carbon cloth in 1 mol L... -1 After standing in Ni(NO3)2 solution for 6 hours, the carbon cloth was removed and dried. S3. Under a protective atmosphere, the carbon cloth is annealed at 700-900℃ for 2 hours under a nitrogen protective atmosphere to obtain porous carbon fiber cloth PCC. S4. Place porous carbon fiber cloth (PCC) and melamine in a crucible at a mass ratio of 1:10, and anneal at 700°C for 0.5 h under a nitrogen protective atmosphere to obtain three-dimensional lithiophilic carbon nanotube material CNT@PCC.

2. The method for preparing the three-dimensional lithiophilic carbon nanotube material according to claim 1, characterized in that, In step S1, the volume ratio of concentrated sulfuric acid to concentrated nitric acid is 1:1, and the temperature of the mixed solution of concentrated sulfuric acid and concentrated nitric acid is 60-80℃. And / or, in step S1, the continuous stirring time is 1-3 hours; And / or, in step S1, the cleaning is performed by cleaning with ethanol several times.

3. The method for preparing the three-dimensional lithiophilic carbon nanotube material according to claim 2, characterized in that, In step S1, the temperature of the mixed solution of concentrated sulfuric acid and concentrated nitric acid is 70°C; And / or, in step S1, the continuous stirring time is 2 hours; And / or, in step S1, the cleaning is performed twice using ethanol.

4. The method for preparing the three-dimensional lithiophilic carbon nanotube material according to claim 1, characterized in that, In step S2, the drying is carried out in an oven at a temperature of 60-120°C for 7-12 hours.

5. The method for preparing the three-dimensional lithiophilic carbon nanotube material according to claim 4, characterized in that, In step S2, the drying process involves drying in an oven at 60°C for 7 hours.

6. A three-dimensional lithiophilic carbon nanotube material, characterized in that, It is prepared using the method for preparing three-dimensional lithiophilic carbon nanotube materials as described in any one of claims 1-5.

7. The application of a three-dimensional lithiophilic carbon nanotube material as described in claim 6 in lithium metal batteries.

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