Nanoporous carbon material and applications and methods of recycling valuable metals from lithium batteries using the same

Abstract

The present application belongs to the technical field of valuable metal recovery from waste lithium batteries, and particularly relates to a kind of nano-porous carbon material and application and a method for recovering valuable metal in lithium battery by using the same.The present application provides a kind of nano-porous carbon material with metal organic framework as precursor, which has stronger reducibility, and after being mixed with retired battery powder, can reduce the activation energy thereof, reduce the temperature of reduction reaction, has obvious promoting effect on carbon thermal reduction reaction, and can faster reduce the metal in retired battery powder into elemental Ni and Co, MnO, Li2O and Li2CO3.Moreover, the nano-porous carbon material provided by the present application can realize high leaching rate of Li and Mn, while keeping the leaching rate of Co and Ni at a low level, so as to realize selective leaching and efficient separation and recovery of Li, Mn, Ni and Co.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of valuable metal recovery from waste lithium batteries, and particularly relates to a nano-porous carbon material, application and method for recovering valuable metals from lithium batteries by using the same. BACKGROUND

[0002] Lithium ion batteries are indispensable components in products such as electric vehicles and mobile electronic devices, and have excellent electrochemical performance, light weight, long cycle life, environmental friendliness and other advantages. With the rapid growth of the consumption of lithium batteries, a large number of retired lithium ion batteries are generated, and valuable metals such as lithium, nickel, cobalt, aluminum and manganese contained therein will not only have a negative impact on the environment if not recovered, but also cause resource waste.

[0003] For retired lithium ion batteries, most of the recyclable metals are concentrated in the positive electrode material. Traditional recovery methods include hydrometallurgy and pyrometallurgy. Hydrometallurgy is widely used in the recovery of retired lithium ion batteries, and has the advantages of high cycle efficiency, high selectivity, mild operating conditions and low energy consumption. However, hydrometallurgy has the disadvantages of complex process and large wastewater discharge. Pyrometallurgy has the advantages of simplicity, efficiency and suitable raw materials, and is usually carried out at a high temperature of more than 1000℃. The target product is usually an alloy containing valuable metal elements such as cobalt, nickel, manganese and iron. However, high reduction temperature also leads to high energy consumption and loss of lithium in the slag. In recent years, many improved pyrometallurgical or combined processes have been proposed, such as first carbon thermal reduction of the positive electrode material of the retired battery, and then subsequent leaching step. Carbon thermal reduction refers to the reduction of metal elements in the battery material with carbon-containing materials such as graphite or lignite before leaching treatment. This step reduces the difficulty of leaching and reduces the consumption of reagents by reducing the metal elements in the battery material to a lower valence state.

[0004] For the carbon thermal reduction step of retired lithium battery recovery, previous studies have focused more on changing the external conditions of chemical reactions such as temperature, pressure, and whether to add catalysts. For the carbon material in the carbon thermal reduction step, graphite, coke powder and lignite are usually selected, but there are still very limited studies on selecting suitable carbon materials to achieve high selective leaching of Li and Mn to achieve efficient separation and recovery of Li, Mn, Ni and Co. SUMMARY

[0005] In view of this, the purpose of the present application is to provide a nano-porous carbon material, a preparation method and application, and a method for recovering valuable metals from lithium batteries by using the same. The prepared nano-porous carbon material has strong reducing property, can sufficiently reduce the valuable metals in the retired battery in the carbon thermal process, and improves the leaching rate and selectivity to achieve the separation of Li, Mn, Ni and Co in the leaching step.

[0006] Specifically, the application provides a kind of nanoporous carbon material, metal organic framework is precursor, and nanoporous carbon is obtained by direct carbonization under inert atmosphere.

[0007] In some specific embodiments of the application, the metal organic framework is Al-PCP (Al(OH)(1,4-NDC)·2H2O) or ZIF-8 ([Zn(MeIm)2] n );

[0008] The Al-PCP (Al(OH)(1,4-NDC)·2H2O) or ZIF-8 ([Zn(MeIm)2] n ) is prepared by solvothermal method or room temperature stirring method.

[0009] In some specific embodiments of the application, the ZIF-8 ([Zn(MeIm)2] n ) Al-PCP (Al(OH)(1,4-NDC)·2H2O) preparation steps are as follows: a certain proportion of Zn(NO3)2·6H2O and 2-methylimidazole are dissolved in methanol respectively, after standing at room temperature for a certain time, ZIF-8 ([Zn(MeIm)2] n ) is obtained by centrifugation and drying;

[0010] The Al-PCP (Al(OH)(1,4-NDC)·2H2O) preparation steps are as follows: a certain proportion of Al(NO3)3·9H2O, 1,4-naphthalene dicarboxylic acid and water are placed in a polytetrafluoroethylene reaction kettle, the oven is heated to naphthalene to 180℃ and kept for 24h, and then Al-PCP (Al(OH)(1,4-NDC)·2H2O) is obtained by filtration and drying.

[0011] In some specific embodiments of the application, the metal organic framework is placed in a quartz crucible, carbonized at 800℃ for 3h under inert gas atmosphere in a tube furnace, and the obtained black powder is washed with HF to remove residual metal impurities, and dried to obtain nanoporous carbon.

[0012] In some specific embodiments of the application, the inert gas atmosphere is nitrogen atmosphere.

[0013] The application also provides a nanoporous carbon material preparation method, which comprises the following preparation steps:

[0014] The metal organic framework Al-PCP (Al(OH)(1,4-NDC)·2H2O) or ZIF-8 ([Zn(MeIm)2] n) Put in a quartz crucible, carbonize at 800 DEG C for 3h under N2 atmosphere of tube furnace, then wash the obtained black powder with HF to remove residual metal impurities, and dry to obtain the nanoporous carbon material.

[0015] The ZIF-8 ([Zn(MeIm)2] n The preparation steps are as follows: a certain proportion of Zn(NO3)2·6H2O and 2-methylimidazole are dissolved in methanol respectively, and then the nanoporous carbon material is obtained after centrifugation and drying after standing at room temperature for a certain time;

[0016] The preparation steps of the Al-PCP (Al(OH)(1,4-NDC)·2H2O) are as follows: a certain proportion of Al(NO3)3·9H2O, 1,4-naphthalene dicarboxylic acid and water are placed in a polytetrafluoroethylene reaction kettle, the oven is heated to naphthalene to 180 DEG C and kept for 24h, and then the nanoporous carbon material is obtained after filtration and drying.

[0017] The application also provides the application of the nanoporous carbon material or the nanoporous carbon material prepared by the preparation method in the preparation of battery electrode materials.

[0018] The application also provides the application of the nanoporous carbon material or the nanoporous carbon material prepared by the preparation method in the recovery of valuable metals in lithium batteries.

[0019] The application also provides a method for recovering valuable metals in lithium batteries by using the nanoporous carbon material or the nanoporous carbon material prepared by the preparation method, characterized by comprising the following steps:

[0020] (1) Pretreating the lithium battery to separate positive and negative mixed materials;

[0021] (2) Mixing the separated positive and negative mixed materials and the nanoporous carbon material, calcining at T1 DEG C for t1 hours under inert gas atmosphere to obtain a carbothermic reduction product;

[0022] (3) Placing the carbothermic reduction product into a leaching agent, leaching at T2 DEG C for t2 minutes, and then filtering to obtain a leaching solution containing lithium salt and manganese salt and a leaching residue containing Ni and Co.

[0023] In some specific embodiments of the application, after mixing the positive and negative mixed materials and the nanoporous carbon material, the carbon content is 15% to 30%; 600≤T1≤800; 1≤t1≤4.

[0024] In some specific embodiments of the application, after mixing the positive and negative mixed materials and the nanoporous carbon material, the carbon content is equal to 20%; T1=750; t1=3.

[0025] In some embodiments of the present application, the leaching agent is a H3PO4 solution, the concentration of the H3PO4 solution is 2.5 mol / L≤ the concentration of the H3PO4 solution ≤ 3.0 mol / L; the liquid-solid ratio of the leaching agent and the carbothermic reduction product is 4-10 mL / g; 20≤T2≤50; 5≤t2≤60.

[0026] In some embodiments of the present application, the leaching agent is a H3PO4 solution, the concentration of the H3PO4 solution is 2.75 mol / L; the liquid-solid ratio of the leaching agent and the carbothermic reduction product is 6 mL / g; T2=40; t2=10.

[0027] In some embodiments of the present application, the leaching liquid can realize the separation of Li and Mn by adjusting the pH.

[0028] In some embodiments of the present application, the metal Ni, Co can be recovered from the leaching residue by wet magnetic separation.

[0029] Compared with the prior art, the nano carbon pore material provided by the present application has stronger reducibility, and after being mixed with the retired battery powder, the nano carbon pore material can reduce the activation energy of the retired battery powder, reduce the temperature of the reduction reaction, and has a significant promoting effect on the carbothermic reduction reaction, so that the metal in the retired battery powder can be more quickly reduced to elemental Ni and Co, MnO, Li2O and Li2CO3. Moreover, the nano carbon pore material provided by the present application can realize high leaching rate of Li and Mn, while keeping the leaching rate of Co and Ni at a low level, so as to realize selective leaching and efficient separation and recovery of Li, Mn and Ni, Co. At the same time, the method for recycling valuable metals in lithium batteries provided by the present application has the advantages of simple process, low cost and being conducive to commercial application. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0031] Figure 1 is a SEM image of ZIF-8-800;

[0032] Figure 2 is a TEM image of ZIF-8-800;

[0033] Figure 3 is a SEM image of Al-PCP-800;

[0034] Figure 4TEM image of Al-PCP-800;

[0035] Figure 5 XRD characterization data of ZIF-8-800 and Al-PCP-800;

[0036] Figure 6 Raman spectrum characterization data of ZIF-8-800;

[0037] Figure 7 Raman spectrum characterization data of Al-PCP-800;

[0038] Figure 8 Nitrogen adsorption-desorption isotherm and pore size distribution of ZIF-8-800;

[0039] Figure 9 Nitrogen adsorption-desorption isotherm and pore size distribution of Al-PCP-800;

[0040] Figure 10 TG (a) of the control group under different heating rates;

[0041] Figure 11 The weight loss rate curve of the control group under different heating rates;

[0042] Figure 12 TG (a) of the ZIF-8-800 experimental unit under different ZIF-8-800 addition ratios;

[0043] Figure 13 The weight loss rate curve of the ZIF-8-800 experimental unit under different ZIF-8-800 addition ratios;

[0044] Figure 14 TG (a) of the Al-PCP-800 experimental unit under different Al-PCP-800 addition ratios;

[0045] Figure 15 The weight loss rate curve of the Al-PCP-800 experimental unit under different Al-PCP-800 addition ratios;

[0046] Figure 16 XRD pattern of the calcined product after adding different types of carbon materials in the retired battery powder;

[0047] Figure 17 Data comparison chart of the influence of different carbon materials on the leaching rate after carbon thermal reduction. DETAILED DESCRIPTION

[0048] 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 should not be used to limit the scope of protection of the present invention. 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.

[0049] Example 1: Preparation of ZIF-8-800 nanoporous carbon

[0050] (1) Preparation of metal-organic framework: 2.4 g of Zn(NO3)2·6H2O and 8.96 g of 2-methylimidazole were dissolved in 40 ml of methanol respectively. After standing at room temperature for 12 hours, ZIF-8([Zn(MeIm)2] was obtained by centrifugation and drying. n );

[0051] (2) The metal-organic framework ZIF-8([Zn(MeIm)2)) n The black powder was placed in a quartz crucible and carbonized at 800°C for 3 hours in a tube furnace under N2 atmosphere. The resulting black powder was then thoroughly washed with HF for 12 hours to remove residual metal impurities. After drying, the nanoporous carbon material ZIF-8-800 was obtained.

[0052] Example 2: Preparation of Al-PCP-800 nanoporous carbon

[0053] (1) Preparation of metal-organic framework: 1.5g of Al(NO3)3·9H2O, 0.432g of 1,4-naphthalenedicarboxylic acid and 40ml of water were placed in a polytetrafluoroethylene reactor. The oven was heated to 180℃ and kept at 24h. After filtration and drying, Al-PCP(Al(OH)(1,4-NDC)·2H2O) was obtained.

[0054] (2) The metal-organic framework Al-PCP(Al(OH)(1,4-NDC)·2H2O) was placed in a quartz crucible and carbonized at 800℃ for 3 hours in a tube furnace under N2 atmosphere. The resulting black powder was then thoroughly washed with HF for 12 hours to remove residual metal impurities. After drying, the nanoporous carbon material Al-PCP-800 was obtained.

[0055] Example 3: Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) tests of ZIF-8-800 and Al-PCP-800

[0056] ZIF-8-800 and Al-PCP-800 prepared in Example 1 and Example 2 were respectively tested by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the test data are shown in Figs. 1 and 2. Figures 1-4

[0057] Fig. 1 shows SEM and TEM images of ZIF-8-800. Figure 1 Fig. 2 shows SEM and TEM images of Al-PCP-800. Figure 2 It can be seen from the SEM and TEM images of ZIF-8-800 that after carbonization and HF acid washing, ZIF-8-800 still retains the typical rhombohedron dodecahedron structure of ZIF-8, and has a typical rhombohedron dodecahedron structure with high crystallinity and uniform particle size distribution, and has high crystallinity and uniform particle size distribution, and the particle size is about 500 nm. Figure 3 Fig. 3 shows SEM and TEM images of ZIF-8-800 after acid washing. 4 It can be found from the SEM and TEM images of Al-PCP-800 that after carbonization and HF acid washing, Al-PCP-800 also well retains the original fiber shape, and has a rich pore structure.

[0058] These results show that ZIF-8-800 and Al-PCP-800 still have good morphology stability after high-temperature carbonization and HF acid washing.

[0059] Example 4: XRD characterization of ZIF-8-800 and Al-PCP-800

[0060] X-ray diffraction (XRD) was used to characterize the crystal phase of Al-PCP-800 and ZIF-8-800 to explore the effect of carbonization and HF acid washing on the structure of the nano-porous carbon, and the test results are shown in Figs. 3 and 4. Figure 5

[0061] From the XRD patterns of the two kinds of nano-porous carbon materials, it can be seen that the acid washing has an effect on the structure of the nano-porous carbon. It can be seen from the pattern that at 2θ = 25° and 44°, there are broad diffraction peaks, which correspond to the (002) interlayer peak of graphite carbon and the (002) and (101) diffraction peaks of amorphous carbon, respectively, indicating that there are graphitized and amorphous carbon phases in the sample. However, no typical in-plane structure characteristics of graphite carbon are observed at 2θ = 13°, indicating that the graphite structure has not been well developed in the carbonization product.

[0062] Example 5: Raman spectrum characterization of ZIF-8-800 and Al-PCP-800

[0063] In order to further explore the carbon structure characteristics of the prepared nano-porous carbon, Raman spectrum was used to characterize ZIF-8-800 and Al-PCP-800, and the test results are shown in Figs. 5 and 6. Figure 6 Figure 7 Fig. 5 shows the Raman spectrum of ZIF-8-800.Fig. 6 shows the Raman spectrum of Al-PCP-800.​​

[0064] It can be seen that the two carbon materials are at 1345 and 1588 cm⁻¹ -1 Both D and G peaks are observed, representing defect-induced vibrational modes in the disordered carbon structure and in-plane vibrational modes in graphitic carbon, respectively. Typically, the intensity of the D peak is proportional to the number of defects in the disordered carbon structure, while the intensity of the G peak is proportional to the degree of graphitization. Therefore, the intensity ratio of the D and G peaks is I0. D / I G It can be used to assess the degree of graphitization in carbon materials. In pure graphitic carbon or single-walled carbon nanotubes, the D peak is unobservable due to the scarcity of defects; only the G peak appears. (From the attached...) Figure 6 and attached Figure 7 It can be seen that obvious D peaks appeared in both carbon materials, and the ID / IG ratio was close to 1, indicating that graphite was not formed during the carbonization process.

[0065] Example 6: N2 adsorption-desorption characterization of ZIF-8-800 and Al-PCP-800

[0066] To investigate the specific surface area and pore distribution of the prepared nanoporous carbon, N2 adsorption-desorption characterization was performed on Al-PCP-800 and ZIF-8-800. Figure 8 and 9 The nitrogen adsorption-desorption isotherms and pore size distribution diagrams are shown for ZIF-8-800 and Al-PCP-800, respectively.

[0067] From the appendix Figure 8 and 9 It can be seen that the adsorption isotherms of both types of nanoporous carbon conform to IUPAC Type I isotherm 1, indicating that the samples have a significant microporous structure. At lower relative pressures (P / P0 < 0.1), both types of nanoporous carbon adsorption isotherms show vigorous absorption, indicating the presence of micropores, with Al-PCP-800 exhibiting a greater adsorption capacity. This is consistent with the adsorption... Figure 9 The pore size distribution curves are consistent. (From the attached...) Figure 9 It can be seen that the pore size and pore volume of Al-PCP-800 are both larger than those of ZIF-8-800, indicating a richer pore structure. The pore sizes of both nanoporous carbons are mainly distributed in the range of 0.3-0.9 nm, with specific surface areas of 811.22 m². 2 / g and 1014.44m 2 / g, calculated using the BET method.

[0068] Example 7: Thermogravimetric Analysis Test

[0069] This test used retired battery powder and nanoporous carbon materials ZIF-8-800 and Al-PCP-800 prepared in Examples 1 and 2.

[0070] The content of valuable metals and carbon in the retired battery powder was measured by ICP-OES and carbon-sulfur analyzer, and the phase composition of the retired battery powder was detected by XRD. The test results are that the content of lithium, aluminum, manganese, cobalt, nickel and carbon is 3.57%, 0.60%, 14.70%, 11.89%, 25.52% and 6.54% respectively. The XRD results show that the main phases in the retired battery powder are LiCoO2, LiNiO2, LiMn2O4, LiNixCoyMn 1-x-y O2and a small amount of carbon, which is consistent with the test results of the carbon-sulfur analyzer.

[0071] This test is divided into three units, including the control unit, ZIF-8-800 experimental unit and Al-PCP-800 experimental unit.

[0072] The control group is only the retired battery powder alone in Ar atmosphere, respectively, with a heating rate of 10℃ / min, 20℃ / min, 40℃ / min, the weight loss curve TG(a) and the weight loss rate curve are shown in FIGS. Figure 10 and 11 .

[0073] The ZIF-8-800 experimental unit is divided into three groups according to the different proportions of ZIF-8-800 added, which are three groups with carbon content of 15%, 20% and 25% after mixing, respectively, and then the thermogravimetric test is carried out in Ar atmosphere with a heating rate of 20℃ / min, the weight loss curve TG(a) and the weight loss rate curve are shown in FIGS. Figure 12 and 13 .

[0074] The Al-PCP-800 experimental unit is divided into three groups according to the different proportions of Al-PCP-800 added, which are three groups with carbon content of 15%, 20% and 25% after mixing, respectively, and then the thermogravimetric test is carried out in Ar atmosphere with a heating rate of 20℃ / min, the weight loss curve TG(a) and the weight loss rate curve are shown in FIGS. Figure 14 and 15 .

[0075] The results of thermogravimetric analysis show that the nanoporous carbon has a relatively obvious promoting effect on the carbothermic reduction reaction. The peak weight loss rate of the retired battery powder added with ZIF-8-800 is the highest when the carbon content is 25% and the heating rate is 20 ℃ / min, and the temperature of the weight loss peak is the lowest, reaching the maximum weight loss rate at 768.53 ℃. The weight loss rate of the retired battery powder added with Al-PCP-800 reaches the peak value of 18.34% at 811.56 ℃ when the carbon content is 20% and the heating rate is 20 ℃ / min. Therefore, relatively speaking, ZIF-8-800 has a better promoting effect on the carbothermic reduction reaction.

[0076] Example 8: Method for recycling valuable metals in lithium batteries by using nanoporous carbon materials

[0077] The lithium battery was pretreated to separate positive and negative mixed materials. The positive and negative mixed materials and the nanoporous carbon material ZIF-8-800 were mixed to make the carbon content of the mixture 20%, and then calcined at 750 ℃ for 3 hours under Ar atmosphere to obtain a carbothermic reduction product.

[0078] The carbothermic reduction product was placed in a 2.75 mol / L H3PO4 solution, the liquid-solid ratio was 6 mL / g, and the leaching reaction was carried out at 40 ℃ for 10 minutes, then filtered to obtain a leaching solution containing lithium salt and manganese salt and a leaching residue containing Ni and Co, and the leaching rates of Li, Mn, Co and Ni were 100%, 100%, 3.22% and 2.06% respectively, showing high selectivity, wherein the leaching rate calculation formula is: leaching rate = (leaching solution volume * leaching solution metal concentration) / metal mass in powder before leaching.

[0079] Example 9: Effect of carbon type on leaching rate test

[0080] The retired battery powder used in this example is the same as that in Example 5.

[0081] In order to study the effect of different types of carbon materials on the phase conversion rate and leaching performance of the calcined product, the XRD characterization and leaching experiment of the calcined product added with different types of carbon materials were carried out. Figure 16 The XRD patterns of the calcined products after adding different types of carbon materials in the retired battery powder and calcining at 750 ℃ for 3h under 20% carbon content are shown in Figure 6. Figure 16 It can be seen that the calcined product added with activated carbon has a larger bump peak at about 2θ = 25°, which is caused by the existence of amorphous electrode material in the calcined product, indicating that the electrode material is not fully reduced, and the bump peak of the calcined product added with Al-PCP-800 is obviously smaller, indicating that the reduction degree of the electrode material is deeper. The calcined product added with ZIF-8-800 has no bump peak, and the diffraction peak intensity of the main products of the three samples has little difference.Figure 17 The results of the medium leaching experiments show that the leaching rates of Li and Mn of the calcined product added with activated carbon are 95.72% and 90.01% respectively, which are lower than the leaching rates of Li and Mn of the calcined products added with Al-PCP-800 and ZIF-8-800; the leaching rates of Li and Mn of the calcined product added with Al-PCP-800 are 98.16% and 90.54% respectively, and the leaching rates of Li and Mn of the calcined product added with ZIF-8-800 are 100% and 100% respectively; the leaching rates of Co and Ni of the calcined product added with activated carbon are 4.04% and 2.32% respectively, which are higher than the leaching rates of Co and Ni of the calcined products added with Al-PCP-800 and ZIF-8-800, the leaching rates of Co and Ni of the calcined product added with Al-PCP-800 are 3.79% and 1.91% respectively, and the leaching rates of Co and Ni of the calcined product added with ZIF-8-800 are 3.22% and 2.06% respectively.

[0082] The above description is merely that of a specific implementation of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Accordingly, the present application is not to be limited to the embodiments described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. Use of a nanoporous carbon material as a carbon thermal reducing agent in the recovery of valuable metals in lithium batteries, characterized in that, The preparation of the nanoporous carbon material comprises the following steps: taking a metal organic framework as a precursor, directly carbonizing under an inert atmosphere, then drying, and acid washing to obtain the nanoporous carbon; The metal organic framework is ZIF-8 or Al-PCP; The preparation steps of the ZIF-8 are as follows: a certain proportion of Zn(NO3)2·6H2O and 2-methyl imidazole are respectively dissolved in methanol, after standing at room temperature for a certain time, centrifugation and drying are performed to obtain the ZIF-8; The preparation steps of the Al-PCP are as follows: a certain proportion of Al(NO3)3·9H2O, 1,4-naphthalene dicarboxylic acid and water are placed in a polytetrafluoroethylene reaction kettle, the oven is heated to 180 DEG C and kept for 24 hours, then filtration and drying are performed to obtain the Al-PCP; The step of directly carbonizing under the inert atmosphere is as follows: the metal organic framework is placed in a quartz crucible, carbonization is performed under the inert gas atmosphere of a tube furnace at 600-800 DEG C for 1-4 hours, the obtained black powder is washed with HF to remove residual metal impurities, and drying is performed to obtain the nanoporous carbon.

2. A method for recovering valuable metals in a lithium battery using a nanoporous carbon material, characterized by, Comprise the following steps: (1) The lithium battery is pretreated to obtain positive and negative electrode mixed materials; (2) The positive and negative electrode mixed materials and the nanoporous carbon material are mixed, calcination is performed at T1 DEG C for t1 hours under an inert gas atmosphere to obtain a carbothermic reduction product; (3) The carbothermic reduction product is placed in a leaching agent, leaching reaction is performed at T2 DEG C for t2 minutes, then filtration is performed to obtain a leaching solution containing lithium salt and manganese salt and a leaching residue containing Ni and Co; The preparation of the nanoporous carbon material comprises the following steps: taking a metal organic framework as a precursor, directly carbonizing under an inert atmosphere, then drying, and acid washing to obtain the nanoporous carbon; The metal organic framework is ZIF-8 or Al-PCP; The preparation steps of the ZIF-8 are as follows: a certain proportion of Zn(NO3)2·6H2O and 2-methyl imidazole are respectively dissolved in methanol, after standing at room temperature for a certain time, centrifugation and drying are performed to obtain the ZIF-8; The preparation steps of the Al-PCP are as follows: a certain proportion of Al(NO3)3·9H2O, 1,4-naphthalene dicarboxylic acid and water are placed in a polytetrafluoroethylene reaction kettle, the oven is heated to 180 DEG C and kept for 24 hours, then filtration and drying are performed to obtain the Al-PCP; The step of directly carbonizing under the inert atmosphere is as follows: the metal organic framework is placed in a quartz crucible, carbonization is performed under the inert gas atmosphere of a tube furnace at 600-800 DEG C for 1-4 hours, the obtained black powder is washed with HF to remove residual metal impurities, and drying is performed to obtain the nanoporous carbon.

3. The method for recycling valuable metals in lithium batteries by using the nanoporous carbon material according to claim 2, characterized in that, After the positive and negative electrode mixed materials and the nanoporous carbon material are mixed, the carbon content is 15% to 30%; 600≤T1≤800； 1≤t1≤4。 4. The method for recycling valuable metals in lithium batteries by using the nanoporous carbon material according to claim 3, characterized in that, After the positive and negative electrode mixed materials and the nanoporous carbon material are mixed, the carbon content is 20%. T1=750； t1=3。 5.The method for recycling valuable metals from lithium batteries by using nanoporous carbon material according to any one of claims 2-4, characterized in that, the leaching agent is a H 3 PO 4 solution, and the concentration of the H 3 PO 4 solution is 2.5 mol / L≤ the concentration of the H 3 PO 4 solution ≤ 3.0 mol / L; the liquid-solid ratio of the leaching agent and the carbothermic reduction product is 4 ~ 10 mL / g; 20≤T2≤50； 5≤t2≤60。 6.The method for recycling valuable metals from lithium batteries by using nanoporous carbon material according to claim 5, characterized in that, the leaching agent is a H 3 PO 4 solution, and the concentration of the H 3 PO 4 solution is 2.75 mol / L; the liquid-solid ratio of the leaching agent and the carbothermic reduction product is 6 mL / g; T2=40； t2=10。 7.The method for recovering valuable metals from lithium batteries using nanoporous carbon material according to claim 6, wherein, the leachate and the leaching residue can continue to be separated; the subsequent analysis step of the leachate includes: adjusting the pH to separate Li and Mn; the subsequent analysis step of the leaching residue includes: using a wet magnetic separation method to recover Ni and Co from the leaching residue, respectively.

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