Manganese selenide-carbon nanotube composite porous carbon material and preparation method thereof

Abstract

The application provides a manganese selenide-carbon nanotube composite porous carbon material and a preparation method thereof. The preparation method takes carbon nanotubes, nano selenium powder, manganese salt and polyvinylpyrrolidone as reaction raw materials, realizes selenization and carbonization in one step through programmed temperature rising, shortens the reaction process, reduces the economic and time cost of production, overcomes the problems that various chemical reagents need to be added in the preparation process of the current negative electrode material and the preparation process is complex, and the preparation method adopted by the application has no pollutant emission, meets the principle of green chemistry, and is beneficial to environmental protection.

Description

Technical Field

[0001] This invention belongs to the field of battery materials, specifically relating to a manganese selenide-carbon nanotube composite porous carbon material and its preparation method. Background Technology

[0002] With the deepening of global energy structure transformation and the implementation of "dual-carbon" goals, batteries, as efficient energy storage carriers, have become the core support for new energy vehicle power systems and large-scale smart grid energy storage. Continuous breakthroughs in their performance are directly related to extending the driving range of electric vehicles, achieving miniaturization and long-term operation of electronic devices, and efficiently utilizing renewable energy. Among the core components of batteries, the anode material plays a decisive role in the overall performance of the battery, especially its energy density, cycle life, and rate performance. Currently, commercially available anode materials are still dominated by graphite-based carbon materials, and their theoretical specific capacity (372 mAh / g) is insufficient to meet the ever-increasing demand for high energy density.

[0003] Transition metal chalcogenides have become a hot topic in high-capacity anode material research in recent years due to their significantly higher theoretical specific capacity than graphite, abundant resource reserves, and relatively mild lithium intercalation potential. Manganese selenide, with its abundant manganese reserves, environmental friendliness, low cost, and objective theoretical specific capacity and unique crystal structure, shows great potential as a next-generation high-performance lithium-ion battery anode material. However, its low electronic conductivity and lithium-ion diffusion rate, coupled with significant volume changes during charge and discharge, lead to pulverization of the electrode material, resulting in rapid capacity decay and poor cycle and rate performance. These drawbacks limit the application of manganese selenides in the field of lithium-ion battery anode materials. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a manganese selenide-carbon nanotube composite porous carbon material and its preparation method. This invention encapsulates manganese selenide nanoparticles within a three-dimensional porous carbon matrix with abundant pores, constructed from porous carbon and carbon nanotubes. This manganese selenide-carbon nanotube composite porous carbon material exhibits high specific capacity and excellent cycling performance at high current densities.

[0005] To achieve the above-mentioned objectives, this invention provides a manganese selenide-carbon nanotube composite porous carbon material, comprising porous carbon, carbon nanotubes, and manganese selenide nanoparticles. The manganese selenide nanoparticles are encapsulated in a three-dimensional porous carbon matrix constructed from porous carbon and carbon nanotubes. The porous carbon comprises amorphous carbon and / or graphitized carbon, and the amorphous carbon is doped with nitrogen, which exists in the form of graphitic nitrogen, pyridine nitrogen, or pyrrole nitrogen. The manganese selenide nanoparticles are connected to the carbon matrix through Se-OC bonds and / or Mn-OC bonds.

[0006] To achieve the above objectives, the present invention also provides a battery negative electrode sheet, which is composed of a negative electrode material, a binder and a conductive material, wherein the negative electrode material is the aforementioned manganese selenide-carbon nanotube composite porous carbon material.

[0007] To achieve the above objectives, the present invention also provides a battery, the battery comprising a negative electrode, an electrolyte, a separator, and a positive electrode, wherein the negative electrode is the battery negative electrode described above.

[0008] To achieve the above objectives, the present invention also provides a method for preparing manganese selenide-carbon nanotube composite porous carbon materials, comprising the following steps:

[0009] (1) Polyvinylpyrrolidone, manganese salt, carbon nanotubes and nano-selenium powder are dispersed in deionized water in sequence, and then the mixed solution is heated to form a viscous colloid;

[0010] (2) The viscous colloid is placed in a tube furnace and heated to 300~500℃ in an inert gas atmosphere and kept at that temperature for 0.5~2h. Then the temperature is raised to 600~1000℃ and kept at that temperature for 0.5~2h. After cooling, manganese selenide-carbon nanotube composite porous carbon material is obtained.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] (1) The manganese selenide-carbon nanotube composite porous carbon material disclosed in this invention anchors manganese selenide nanoparticles onto a three-dimensional porous carbon matrix constructed from porous carbon and carbon nanotube particles through Se-OC bonds and Mn-OC bonds, which can effectively enhance the bonding force between manganese selenide nanoparticles and carbon matrix, and significantly improve the conductivity and cycle performance of the material.

[0013] (2) This invention combines molecular self-assembly and confined crystallization. First, polyvinylpyrrolidone is chelated with manganese salt and carbon nanotubes are uniformly dispersed in the system. Heating forms a uniform gel precursor, which confines manganese salt and selenium nanoparticles in the network formed by polyvinylpyrrolidone and carbon nanotubes, providing the necessary structural template for the formation of porous carbon skeleton. Then, partial carbonization is carried out at the same time as selenization, and nano-manganese selenide is wrapped in carbon matrix, ensuring strong interfacial bonding between nano-manganese selenide and carbon matrix, which can prevent nano-manganese selenide from falling off, thereby improving the cycling performance of the material.

[0014] (3) When the viscous colloid is selenized, the nano-selenium powder generates selenium vapor upon heating. The selenium vapor selenizes the manganese salt to form manganese selenide. At the same time, polyvinylpyrrolidone undergoes slow pyrolysis, releasing nitric oxide and ammonia. The generation of carbon monoxide, ammonia, and selenium vapor leads to the formation of a porous structure in the carbon matrix, giving the anode material a high specific surface area and hierarchical channels. This structure not only provides a fast transport channel for lithium or sodium ions but also effectively mitigates the volume expansion effect during charging and discharging through a pore buffering mechanism, thereby improving the material's service life.

[0015] (4) The present invention achieves selenization and carbonization in one step by programmed temperature rise, which shortens the reaction process, reduces the economic and time costs of production, overcomes the problems of adding various chemical reagents and complicated preparation processes in the current preparation of negative electrode materials, and the preparation method adopted in the present invention has no pollutant emissions, conforms to the principle of green chemistry, and is beneficial to environmental protection.

[0016] (5) Based on the above synergistic effect, the manganese selenide composite carbon / carbon nanotube material prepared by the present invention exhibits excellent electrochemical performance. Its initial discharge capacity can reach 1589.5 mAh / g, and its initial charging capacity can reach 1041.4 mAh / g. At a current density of 2 A / g, after 1000 cycles, the capacity retention rate of the material is still as high as 99.7%, and it has a very good cycle life. Attached Figure Description

[0017] Figure 1 A schematic diagram of the preparation process of manganese selenide-carbon nanotube composite porous carbon material;

[0018] Figure 2 SEM image of the manganese selenide-carbon nanotube composite porous carbon material prepared in Example 2;

[0019] Figure 3 This is a TEM image of the manganese selenide-carbon nanotube composite porous carbon material prepared in Example 2;

[0020] Figure 4 SEM image of the manganese selenide composite porous carbon material prepared in Comparative Example 1;

[0021] Figure 5 SEM image of the carbon nanotube composite porous carbon material prepared in Comparative Example 2;

[0022] Figure 6 XRD patterns of the composite materials prepared in Example 2, Comparative Example 1, and Comparative Example 2;

[0023] Figure 7 The Raman spectra of Example 2, Comparative Example 1, and Comparative Example 2 are shown below.

[0024] Figure 8 XPS spectra of the Mn 2p level, Se 3D level, N 1s level, and C 1s level in Example 2;

[0025] Figure 9 The accompanying figures show the isothermal nitrogen adsorption / desorption and specific surface area of ​​the composite materials prepared in Example 2, Comparative Example 1, and Comparative Example 2.

[0026] Figure 10 The composite materials prepared in Example 2, Comparative Example 1, and Comparative Example 2 were tested for 200 cycles at a current density of 0.2 A / g.

[0027] Figure 11 Rate performance of the composite materials prepared in Example 2, Comparative Example 1, and Comparative Example 2 at current densities of 0.1 A / g, 0.2 A / g, 0.5 A / g, 1 A / g, 3 A / g, 8 A / g, 6 A / g, and 2 A / g;

[0028] Figure 12 The cycling performance of the composite materials prepared in Example 2, Comparative Example 1 and Comparative Example 2 at a current density of 2A / g for 1000 cycles;

[0029] Figure 13 EIS diagrams of the composite materials prepared in Example 2, Comparative Example 1, and Comparative Example 2. Detailed Implementation

[0030] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0032] Unless otherwise specified, all reagents used are commercially available.

[0033] This invention provides a manganese selenide-carbon nanotube composite porous carbon material, comprising porous carbon, carbon nanotubes, and manganese selenide nanoparticles. The manganese selenide nanoparticles are encapsulated in a three-dimensional porous carbon matrix constructed from porous carbon and carbon nanotubes. The porous carbon includes amorphous carbon and / or graphitized carbon. The amorphous carbon is doped with nitrogen, which exists in two or more forms selected from graphitic nitrogen, pyridine nitrogen, and pyrrole nitrogen. The manganese selenide nanoparticles are connected to the carbon matrix through Se-OC bonds and / or Mn-OC bonds.

[0034] In some embodiments of the present invention, the porous carbon includes amorphous carbon and graphitized carbon, and the nitrogen exists in three forms: graphitic nitrogen, pyridine nitrogen, and pyrrole nitrogen.

[0035] In some embodiments of the present invention, the manganese selenide nanoparticles are connected to the carbon matrix via Se-OC bonds and Mn-OC bonds.

[0036] In some embodiments of the present invention, the average particle size of the manganese selenide nanoparticles is 38.17~81.39 nm.

[0037] In some embodiments of the present invention, the average particle size of the manganese selenide nanoparticles is 44.67 nm.

[0038] In some embodiments of the present invention, the specific surface area of ​​the manganese selenide composite carbon / carbon nanotube material is 146.18~216.14 m². 2 / g.

[0039] In some embodiments of the present invention, the specific surface area of ​​the manganese selenide composite carbon / carbon nanotube material is 199.26 m². 2 / g.

[0040] In some embodiments of the present invention, the average pore size of the manganese selenide composite carbon / carbon nanotube material is 36.21~70.96 nm.

[0041] In some embodiments of the present invention, the average pore size of the manganese selenide composite carbon / carbon nanotube material is 44.21 nm.

[0042] This invention also provides a manganese selenide composite carbon / carbon nanotube material, comprising the following steps:

[0043] (1) Polyvinylpyrrolidone, manganese salt, carbon nanotubes and nano-selenium powder are dispersed in deionized water in sequence, and then the mixed solution is heated to form a viscous colloid;

[0044] (2) The viscous colloid is placed in a tube furnace and heated to 300~500℃ in an inert gas atmosphere. It is kept at the temperature for 0.5~2h for selenization, and then heated to 600~1000℃ and kept at the temperature for 0.5~2h for carbonization. After cooling, manganese selenide-carbon nanotube composite carbon material is obtained.

[0045] In some preferred embodiments of the present invention, the mass ratio of polyvinylpyrrolidone, manganese salt, carbon nanotubes, and nano-selenium powder is 1~8:4:0.05~0.2:1.5.

[0046] In some specific embodiments of the present invention, the mass ratio of polyvinylpyrrolidone, manganese salt, carbon nanotubes, and nano-selenium powder is 1:4:0.2:1.5, 4:4:0.05:1.5, 4:4:0.1:1.5, 4:4:0.2:1.5, and 8:4:0.05:1.5.

[0047] In some preferred embodiments of the present invention, the manganese salt is manganese nitrate, manganese chloride, manganese acetate, or manganese sulfate.

[0048] In some preferred embodiments of the present invention, the carbon nanotubes are carboxylated carbon nanotubes.

[0049] In some preferred embodiments of the present invention, the inert gas is nitrogen, argon or helium.

[0050] In some preferred embodiments of the present invention, the heating rate of the selenization stage is 1~8℃ / min, and the heating rate of the carbonization stage is 5~20℃ / min.

[0051] In some specific embodiments of the present invention, the heating rate of the selenization stage is 1℃ / min, 4℃ / min, or 8℃ / min.

[0052] In some preferred embodiments of the present invention, the selenization temperature is 300~500°C.

[0053] In some specific embodiments of the present invention, the selenization temperature is 300°C, 400°C, or 500°C.

[0054] In some specific embodiments of the present invention, the selenization time is 0.5h, 1h, or 2h.

[0055] In some specific embodiments of the present invention, the heating rate of the carbonization stage is 5°C / min, 10°C / min, or 20°C / min.

[0056] In some preferred embodiments of the present invention, the carbonization temperature is 600~1000°C.

[0057] In some specific embodiments of the present invention, the carbonization temperature is 600°C, 800°C, or 1000°C.

[0058] In some specific embodiments of the present invention, the carbonization time is 0.5h, 1h, or 2h.

[0059] The present invention also provides a battery negative electrode sheet, which is composed of a negative electrode material, a binder and a conductive material, wherein the negative electrode material is the manganese selenide-carbon nanotube composite porous carbon material described above.

[0060] The present invention also provides a battery comprising a negative electrode, an electrolyte, a separator, and a positive electrode, wherein the negative electrode is the battery negative electrode described above.

[0061] In this invention, the type of battery can be a conventional battery in the art, such as a lithium-ion battery or a sodium-ion battery, preferably a lithium-ion battery.

[0062] Example 1

[0063] (1) Polyvinylpyrrolidone, manganese acetate, carboxylated carbon nanotubes and nano-selenium powder in a mass ratio of 4:4:0.1:1.5 were ultrasonically dispersed in deionized water, and the mixed solution was then heated to form a viscous colloid.

[0064] (2) The viscous colloid was placed in a tube furnace and heated to 400°C at a heating rate of 1°C / min under an inert gas atmosphere. It was then held for 1 hour for selenization. Then, it was heated to 800°C at a heating rate of 10°C / min and held for 1 hour for carbonization. After cooling, manganese selenide-carbon nanotube composite porous carbon material was obtained.

[0065] The preparation steps of the manganese selenide-carbon nanotube composite porous carbon materials in Examples 2-20 are the same as those in Example 1. The specific parameters are shown in Table 1. Except for the parameters listed in Table 1, the other conditions are the same as those in Example 1.

[0066]

[0067] Comparative Example 1

[0068] (1) Polyvinylpyrrolidone, manganese acetate and nano selenium powder in a mass ratio of 4:4:1.5 were ultrasonically dispersed in deionized water, and then the mixed solution was heated to evaporate the water to form a viscous colloid.

[0069] (2) The viscous colloid was placed in a tube furnace and heated to 400°C at 4°C / min under an inert gas atmosphere and held for 1 hour for selenization. Then it was heated to 800°C at 10°C / min and held for 1 hour for carbonization. After cooling, manganese selenide composite porous carbon material was obtained.

[0070] Comparative Example 2

[0071] (1) Polyvinylpyrrolidone, carboxylated carbon nanotubes and nano-selenium powder in a mass ratio of 4:0.1:1.5 were ultrasonically dispersed in deionized water, and then the mixed solution was heated to evaporate the water to form a viscous colloid.

[0072] (2) The viscous colloid was placed in a tube furnace and heated to 400°C at 4°C / min under an inert gas atmosphere. It was kept at the temperature for 1 hour for selenization. Then it was heated to 800°C at 10°C / min and kept at the temperature for 1 hour for carbonization. After cooling, carbon nanotube composite carbon material was obtained.

[0073] Comparative Example 3

[0074] (1) Polyvinylpyrrolidone, manganese acetate, carboxylated carbon nanotubes and nano-selenium powder in a mass ratio of 4:4:0.1:1.5 were ultrasonically dispersed in deionized water in sequence, and then the mixed solution was heated to evaporate the water to form a viscous colloid.

[0075] (2) The mixed mixture was placed in a tube furnace and heated to 400°C at 4°C / min under an inert gas atmosphere. The mixture was kept at the temperature for 1 hour for selenization. After cooling, manganese selenide-carbon nanotube composite porous carbon material was obtained.

[0076] Comparative Example 4

[0077] (1) Polyvinylpyrrolidone, manganese acetate, carboxylated carbon nanotubes and nano-selenium powder in a mass ratio of 4:4:0.1:1.5 were ultrasonically dispersed in deionized water in sequence, and then the mixed solution was heated to evaporate the water to form a viscous colloid.

[0078] (2) The mixed mixture was placed in a tube furnace and then heated to 800℃ at 10℃ / min and held for 1h for carbonization. After cooling, manganese selenide-carbon nanotube composite porous carbon material was obtained.

[0079] Comparative Example 5

[0080] Citric acid monohydrate was used instead of polyvinylpyrrolidone, otherwise the same as in Example 2.

[0081] Test Example 1:

[0082] The average particle size, average pore size, and specific surface area of ​​the materials prepared in Examples 1-20 and Comparative Examples 1-5 were tested, and the test results are shown in Table 2.

[0083]

[0084] Test Example 2

[0085] The materials prepared by Examples 1-20 and Comparative Examples 1-5 were used as active materials (80% by mass), mixed with sodium carboxymethyl cellulose (CMC) binder (10% by mass) and conductive carbon black (10% by mass), and an appropriate amount of deionized water was added as a solvent. The mixture was then prepared into a uniform negative electrode slurry using a high-speed homogenizer.

[0086] The slurry was uniformly coated onto the surface of the copper foil current collector using a doctor blade coater, and then transferred to a vacuum drying oven to dry at 120°C for 12 hours. After drying, it was cut into circular electrode sheets with a diameter of 14 mm to complete the preparation of the negative electrode sheet for lithium-ion batteries.

[0087] Place the prepared negative electrode sheet at the bottom of the CR2032 stainless steel battery case, then place the Celgard 2325 separator and lithium metal counter electrode sheet in sequence, and add 3-5 drops of 1.0 mol / L LiPF6 EC / DMC (volume ratio 1:1) electrolyte to ensure that the separator is completely wetted; after covering with the second separator, place the stainless steel spring sheet, cover with the positive electrode case, and seal with a sealing machine under 8 MPa pressure. After standing for 12 hours, the half-cell assembly is completed.

[0088] The half-cells, after undergoing static treatment, were subjected to 200 constant current charge-discharge cycles at a current density of 0.2 A / g, rate performance tests were conducted at current densities of 0.1 A / g, 0.2 A / g, 0.5 A / g, 1 A / g, 3 A / g, 8 A / g, 6 A / g, and 2 A / g, and 1000 constant current charge-discharge cycles were conducted at a current density of 2 A / g. Impedance tests were performed on an electrochemical workstation. Specific test results are shown in Table 3.

[0089]

[0090] Figure 2 The image shows a SEM image of the manganese selenide-carbon nanotube composite porous carbon material prepared in Example 2. As can be seen from the image, the carbon nanotube network effectively restricts the movement of manganese selenide nanoparticles, thereby enhancing the porosity of the material. Figure 3 This further confirms that the nano-manganese selenide particles are uniformly distributed in the carbon matrix formed by porous carbon and carbon nanotubes. Figure 4 The composite material prepared in Comparative Example 1 exhibits a distinct fibrous structure, which is formed by an interwoven network of carbon nanotubes. The interaction between the carbon nanotubes results in a large number of pores within the material. Figure 5 Comparative Example 2 shows that nano-manganese selenide particles are uniformly distributed in a matrix formed of porous carbon and carbon nanotubes.

[0091] Figure 6XRD patterns of the composite materials prepared in Example 2, Comparative Example 1, and Comparative Example 2 are shown. In the composite material of Comparative Example 2, a broad diffraction peak at 26.3° is observed, corresponding to the (002) crystal plane of amorphous carbon. In the composite material of Example 2, the intensity of this diffraction peak is significantly reduced because manganese selenide dominates in these composite materials, with diffraction peaks at 28.3° (111), 47.0° (220), and 58.5° (222), respectively. In the composite materials of Example 2 and Comparative Example 1 containing manganese selenide, the (002) diffraction peaks of carbon and manganese selenide can appear simultaneously, further demonstrating the successful bonding of manganese selenide nanoparticles to the carbon matrix via a combined "carbonization-selenization" process. Furthermore, a comparative analysis of the (002) diffraction peaks of Comparative Example 2 and pure carbon revealed that the full width at half maximum (FWHM) of the composite material of Comparative Example 2 decreased from 4.572° for pure carbon to 3.659°. The reduction in the half-width at half-maximum (HWHM) indicates that the crystallinity of the carbon phase was significantly improved after the addition of carbon nanotubes, thereby enhancing the structural stability and electronic conductivity of this composite material. Figure 7 The Raman spectra of Example 2, Comparative Example 1, and Comparative Example 2 are shown. All samples exhibit a typical D band (approximately 1350 cm⁻¹). -1 ) and G-band (approximately 1580cm) -1 The diffraction peaks further confirmed that these samples did indeed contain carbon.

[0092] Figure 8 The XPS spectra of the Mn 2p level, Se 3d level, N 1s level, and C 1s level are shown in Example 2. High-resolution Mn 2p level spectral analysis shows a peak value of 641.7 eV at the Mn 2p3 / 2 level and a peak value of 653.5 eV at the Mn 2p1 / 2 level. A characteristic satellite peak was also observed at 641.7 eV, confirming that Mn 2p2 / 2 has a peak value of 653.5 eV. 2+ and Mn 3+ The presence of these elements indicates that, in addition to the Mn-Se bonds, MnSe is also connected to oxygen-containing functional groups on the carbon matrix via Mn-OC bonds. The Se 3d spectrum shows three distinct peaks: 53.9 eV and 56.1 eV correspond to the Se3ds / 2 and Se 3d3 / 2 energy levels of selenium, respectively; while the peak at 59.2 eV belongs to the selenium oxide species (SeOx), indicating that the manganese selenide nanoparticles are connected to the carbon matrix via Se-OC bonds. The N 1s spectrum results show the presence of nitrogen species such as pyridyl-N (398.3 eV), pyrrole-N (399.9 eV), and graphitic-N (401.7 eV) in the sample, proving that nitrogen has been successfully incorporated into the carbon matrix and exists in the forms of pyridyl nitrogen, pyrrole nitrogen, and graphitic nitrogen.

[0093] Figure 9 The N2 adsorption-desorption isotherms all exhibited H4-type hysteresis loops, indicating that the sample possesses microporous and mesoporous structures. These pore structures are mainly formed by the release of gases generated during PVP carbonization; simultaneously, the interactions between porous carbon, carbon nanotubes, and MnSe also promote the formation of pore structures.

[0094] Combination Figure 10 , 11 The test data in Tables 12, 13, and 3 show that the electrochemical performance of the manganese selenide-carbon nanotube composite porous carbon material is significantly better than that of the material prepared in the comparative example. This is because the carbon matrix formed by polyvinylpyrrolidone and carbon nanotubes provides an efficient channel for electron transport. The network structure formed by carbon nanotubes and the porosity retained by the carbonization of polyvinylpyrrolidone enhance the conductivity of the material, and the high specific surface area helps to improve the lithium-ion storage performance. In addition, the synergistic effect between the porous carbon formed by the carbonization of polyvinylpyrrolidone and the carbon nanotubes effectively restricts the diffusion of manganese selenide nanoparticles, and the combination of both Mn and Se with the carbon matrix results in the manganese selenide composite carbon / carbon nanotube material exhibiting excellent high reversible specific capacity.

[0095] For those skilled in the art, several simple deductions or substitutions can be made without departing from the inventive concept, without requiring creative effort. Therefore, any simple improvements made to this invention by those skilled in the art based on the disclosure of this invention should be within the scope of protection of this invention. The above embodiments are preferred embodiments of this invention, and all processes similar to this invention and equivalent changes should fall within the scope of protection of this invention.

Claims

1. A manganese selenide-carbon nanotube composite porous carbon material, characterized by, The manganese selenide nano-particles are encapsulated in a three-dimensional porous carbon matrix structure formed by carbon nanotubes and porous carbon, and the manganese selenide nano-particles are connected to the carbon matrix through Se-O-C bonds and Mn-O-C bonds.

2. The manganese selenide-carbon nanotube composite porous carbon material of claim 1, wherein, The average particle size of the manganese selenide nano-particles is 38.17-81.39 nm.

3. The manganese selenide-carbon nanotube composite porous carbon material of claim 1, wherein, The specific surface area of the manganese selenide-carbon nanotube composite porous carbon material is 146.18-216.14 m 2 / g.

4. The manganese selenide-carbon nanotube composite porous carbon material of claim 1, wherein, The average pore size of the manganese selenide-carbon nanotube composite porous carbon material is 36.21-70.96 nm.

5. The preparation method of the manganese selenide-carbon nanotube composite porous carbon material according to claim 1, comprising the following steps: (1) dispersing polyvinylpyrrolidone, manganese salt, carbon nanotubes and nano selenium powder in deionized water in sequence, and then heating the mixed solution to form a viscous colloid; (2) placing the viscous colloid in a tube furnace, heating to 300-500℃ under an inert gas atmosphere, and then performing selenization for 0.5-2 h, and then heating to 600-1000℃ for 0.5-2 h for carbonization, and then cooling to obtain the manganese selenide-carbon nanotube composite porous carbon material.

6. The method of claim 5, wherein the manganese selenide-carbon nanotube composite porous carbon material is prepared by the steps of: mixing manganese selenide and carbon nanotubes; and heating the mixture to form the manganese selenide-carbon nanotube composite porous carbon material. The mass ratio of the polyvinylpyrrolidone, manganese salt, carbon nanotubes and nano selenium powder is 1-8:4:0.05-0.2:1.

5.

7. The method of claim 5, wherein the manganese selenide-carbon nanotube composite porous carbon material is prepared by the steps of: mixing manganese selenide and carbon nanotubes; and heating the mixture to form the manganese selenide-carbon nanotube composite porous carbon material. The manganese salt is manganese nitrate, manganese chloride, manganese acetate or manganese sulfate; the carbon nanotubes are carboxylated carbon nanotubes; and the inert gas is nitrogen, argon or helium.

8. The method of claim 5, wherein the manganese selenide-carbon nanotube composite porous carbon material is prepared by the steps of: mixing manganese selenide and carbon nanotubes; and heating the mixture to form the manganese selenide-carbon nanotube composite porous carbon material. The heating rate of the selenization stage is 1-8℃, and the heating rate of the carbonization stage is 5-20℃.

9. A battery negative electrode sheet characterized by comprising: The battery comprises a negative electrode material, a binder and a conductive material, and the negative electrode material is the manganese selenide-carbon nanotube composite porous carbon material according to claim 1.

10. A battery, characterized by The battery comprises a negative electrode material, a binder and a conductive material, and the negative electrode material is the manganese selenide-carbon nanotube composite porous carbon material according to claim 1.

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