Lithium-carbon particles and methods for making the same

Abstract

A lithium-carbon particle and a preparation method thereof are provided. The lithium-carbon particle comprises: a porous particle and metal lithium filled in the pores of the porous particle, the porous particle is formed by interweaving carbonaceous frameworks, the carbonaceous frameworks comprise crystallized carbon frameworks and amorphous carbon layers wrapped on the surfaces of the crystallized carbon frameworks, and the amorphous carbon layers also exist on the surface of the particle. Optionally, the amorphous carbon layers also contain nano metal particles. The lithium-carbon particle has a three-dimensional carbon framework structure inside, can provide reserved space for metal lithium deposition, relieve the volume expansion of the metal lithium negative electrode, and the conductive capacity of the framework structure can reduce the current density on the surface of the electrode and reduce the growth of lithium dendrites. The electrode prepared by using the lithium-carbon particle has a stable structure and is beneficial to the preparation of a long-life cycle electrode.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of new materials, and particularly relates to a lithium-carbon particle and a preparation method thereof. BACKGROUND

[0002] At present, the energy density of lithium ion batteries has reached the limit of its battery system, and it is urgent to seek a new battery system with high energy density. The metal lithium negative electrode has the advantages of high specific capacity (3860 mAh / g) and low electrode potential (-3.04 V vs. SHE), and is an optimal material for significantly improving the energy density of the battery system. However, the metal lithium negative electrode battery continuously forms dendrites and "dead lithium" during the cycle process, sharply consumes electrolyte, leads to low coulombic efficiency and short cycle life of the battery. More importantly, the growth of dendrites may pierce the separator, causing internal short circuit of the battery, and the heat released by the battery is easy to cause safety accidents of the battery.

[0003] To solve the problems of metal lithium dendrites and "dead lithium", increasing the specific surface area of metal lithium and reducing the current density on the surface of metal lithium are effective means to inhibit the growth of dendrites. Among them, the most representative is the FMC company of the United States, which uses a melt emulsification method to prepare metal lithium particles. The lithium particles with a modified surface can exist stably in dry air. However, when the material is prepared into an electrode sheet, the modified layer is easily damaged, leading to safety accidents. In addition, the lithium particles prepared by this melt emulsification technology have a large size, and the preparation method of melt emulsification requires high temperature, vigorous stirring and repeated filtration and washing, which is complex in steps and high in equipment cost.

[0004] The Institute of Nanotechnology and Nanobionics, Chinese Academy of Sciences, prepared a metal lithium-skeleton carbon composite material (Chinese patent application No. CN 201410395114.0). The metal lithium in a molten state is uniformly mixed with a porous carbon material carrier, and a lithium-carbon composite material is obtained by cooling. The material effectively inhibits the growth of dendrites, improves the safety of the battery, and provides high specific capacity and good cycle performance. The above method has a significant effect on inhibiting the growth of dendrites, but the preparation of the above metal lithium-skeleton carbon composite material is still at the laboratory level, the product yield is low, the consistency is poor, and it is difficult to mass-produce.

[0005] Therefore, it is urgent to develop a method for mass-producing lithium-carbon particles with high yield. SUMMARY

[0006] To solve the above problems, the present inventors provide a lithium-carbon particle and a preparation method thereof. The lithium-carbon particle has a three-dimensional carbon skeleton structure inside, which can provide a reserved space for metal lithium deposition, relieve the volume expansion of the metal lithium negative electrode, and reduce the current density on the electrode surface to reduce the growth of lithium dendrites. The lithium-carbon particle has a stable electrode structure, which is conducive to the preparation of a long-life cycle electrode.

[0007] Specifically, one aspect of the present application provides a lithium-carbon particle, which comprises: a porous particle as a carrier, the porous particle is a micron-sized particle with nanoscale pores inside and on the surface, which is formed by interweaving carbonaceous skeletons, the carbonaceous skeleton includes a crystallized carbon skeleton and an amorphous carbon layer wrapped on the surface of the crystallized carbon skeleton, the non-porous part on the surface of the porous particle is also covered with the amorphous carbon layer, and the amorphous carbon layer on the surface of the particle and the amorphous carbon layer on the surface of the crystallized carbon skeleton are formed of the same material; and metal lithium filled in the pores of the porous particle.

[0008] The schematic structure of the lithium-carbon particle of the present application is shown in Figure 1 The surface of the crystallized carbon skeleton 1 is wrapped with an amorphous carbon layer 2 to form a carbonaceous skeleton, the carbonaceous skeletons are interwoven to form a porous particle, the pores of the porous particle are filled with metal lithium 3, and the surface of the porous particle also has an amorphous carbon layer 2. Figure 1 This is only a schematic diagram, and only the non-porous part on the surface of the porous particle of the present application is covered with the amorphous carbon layer 2.

[0009] In the present application, the crystallized carbonaceous material refers to a material in which carbon atoms constituting the material are arranged in order according to certain rules (microstructure), and the amorphous material refers to a material in which atoms are arranged in order in a short range and disorder in a long range, which can also be called amorphous material.

[0010] In some embodiments, the amorphous carbon layer also contains nanometer metal particles.

[0011] In some embodiments, the size of the porous particle ranges from 1 micrometer to 50 micrometers, and the porosity ranges from 15% to 85%.

[0012] In some embodiments, the thickness of the amorphous carbon layer is 10 nm to 600 nm.

[0013] In some embodiments, the crystallized carbon skeleton is at least one of carbon nanotubes, graphene, carbon fibers, carbon-based metal oxide fibers, and carbon-based covalent organic fibers.

[0014] In some embodiments, the amorphous carbon layer is a carbonization product of an organic material blended with the crystallized carbon skeleton.

[0015] In some embodiments, the organic material is selected from the group consisting of an organic binder, an organic filler, and a crosslinking agent.

[0016] In some embodiments, the organic binder is selected from the group consisting of polyvinyl alcohol, polyvinylidene fluoride, polybutylene styrene, polystyrene, polycarboxyl cellulose, cyanoacrylate, polyacrylic acid, cyclodextrin, cyclic ether derivatives, polyurethane, methacrylate, epoxy resin, vinyl acetate polymer, polyimide, organofluorine polymer, organosiloxane, polyethylene glycol, polyethylene, polyvinyl chloride, polypropylene, glycerol, hydroxyphenyl ethyl ester and its derivatives, monosaccharide or polysaccharide polymer.

[0017] In some embodiments, the organic filler is selected from the group consisting of plastic microparticles (polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), etc.), benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, calcium propionate, dehydroacetic acid salt.

[0018] In some embodiments, the cross-linking agent is selected from the group consisting of high molecular polymers of acrylic acid bonded allyl sucrose or pentaerythritol allyl ether, benzoyl peroxide, diethylenetriamine, hydrated sodium borate, cellulose derivatives, isothiazolinone.

[0019] In some embodiments, the nano metal particles have a size ranging from 5 nm to 200 nm and are dispersedly embedded in the outer amorphous carbon layer.

[0020] Another aspect of the present application provides a method for preparing lithium-carbon particles, the method comprising:

[0021] Step 1, forming a slurry of an organic binder, a filler including a crystalline carbon skeleton material, an organic filler (other than the crystalline carbon skeleton material), and an optional inorganic filler, a cross-linking agent, and a solvent;

[0022] Step 2, performing spray granulation on the slurry obtained in Step 1;

[0023] Step 3, heating the material obtained in Step 2 at a temperature ranging from 300°C to 1200°C under protection of an inert atmosphere, and obtaining porous particles after cooling;

[0024] Step 4, stirring and mixing the porous particles obtained in Step 3 with molten lithium to obtain lithium-carbon particles.

[0025] In some embodiments, the mass ratio of the binder, the filler, the cross-linking agent, and the solvent is (4-15 parts) : (10-30 parts) : (0.01-20 parts) : (100-7000 parts).

[0026] In some embodiments, the mass proportion of the crystalline carbon skeleton material in the filler is 15% to 100%.

[0027] In some embodiments, the organic binder is selected from the group consisting of polyvinyl alcohol, polyvinylidene fluoride, polybutylene styrene, polystyrene, polycarboxyl cellulose, cyanoacrylate, polyacrylic acid, cyclodextrin, cyclic ether derivatives, polyurethane, methacrylate, epoxy resin, vinyl acetate polymer, polyimide, organofluorine polymer, organosiloxane, polyethylene glycol, polyethylene, polyvinyl chloride, polypropylene, glycerol, hydroxyphenyl ethyl ester and its derivatives, monosaccharide or polysaccharide polymer.

[0028] In some embodiments, the organic filler is selected from the group consisting of plastic microparticles (PP, PET, PS), benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, calcium propionate, dehydroacetic acid salt.

[0029] In some embodiments, the inorganic filler is selected from the group consisting of metal nanoparticles, metal oxides, metal nitrides, calcium carbonate, hydrous magnesium silicate, mica, hydrated silicon dioxide, silicon dioxide.

[0030] In some embodiments, the cross-linking agent is selected from the group consisting of high molecular polymers of acrylic acid bonded allyl sucrose or pentaerythritol allyl ether, benzoyl peroxide, diethylenetriamine, hydrated sodium borate, cellulose derivatives, isothiazolinone.

[0031] In some embodiments, the solvent is selected from the group consisting of water, tetrachloroethylene, toluene, turpentine, acetone, methyl acetate, ethyl acetate, pentane, n-hexane, cyclohexane, octane, lemon essence, alcohol, dimethylbenzene, toluene cyclohexanone, isopropyl alcohol, diethyl ether, propylene oxide, methyl butanone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, acetonitrile, pyridine, phenol, ethylenediamine.

[0032] In some embodiments, the slurry formed in step 1 has a solid content ranging from 0.1% to 12%.

[0033] In some embodiments, the atomization conditions of step 2 include: the atomization chamber drying temperature is 200°C to 450°C, the atomization rate is 2L / hour to 30L / hour, and the carrier gas pressure is 0.2MPa to 0.8MPa.

[0034] In some embodiments, the heating in step 3 is performed for 2-24 hours.

[0035] In some embodiments, the temperature of the molten lithium in step 4 is 175°C to 850°C.

[0036] In some embodiments, the lithium-carbon particles obtained in step 4 can be optionally surface-coated with at least one of inorganic nano-oxides (aluminum oxide, lithium oxide, etc.), inorganic nano-nitrides (copper nitride, lithium nitride, etc.), inorganic nano-fluorides (lithium fluoride, magnesium fluoride, etc.), metal salts with oxygen-containing acid radicals (zinc sulfate, lithium oxalate, etc.), nitrogen-containing organic substances (polymethylpyrrolidone, melamine, etc.), and sulfur-containing organic substances (polystyrene sodium sulfonate).

[0037] In some embodiments, the surface-coating of the lithium-carbon particles can be performed in an oxygen-containing or nitrogen-containing atmosphere, or by treating the lithium-carbon particles with a compound having reactivity with lithium.

[0038] The present application has at least one of the following advantages:

[0039] 1. The lithium-carbon particles can be prepared industrially, and the metallic lithium is completely infiltrated therein, the material is not delaminated inside, and has no pores.

[0040] 2. The lithium-carbon particles can form an internal conductive three-dimensional carbon skeleton structure, can provide reserved space for the deposition of metallic lithium, and can relieve the volume expansion of the metallic lithium negative electrode.

[0041] 3. The conductive ability of the carbon skeleton structure can reduce the current density on the surface of the electrode and reduce the growth of lithium dendrites.

[0042] 4. The electrode prepared from the lithium-carbon particles has a stable structure, which is conducive to the preparation of long-life cycle electrodes. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 An illustration of the lithium-carbon particles of the present application.

[0044] Figure 2 A scanning electron microscope image of the lithium-carbon particles containing silver nanoparticles prepared in Example 1.

[0045] Figure 3 A specific capacity test curve of the lithium-carbon particles in Example 2.

[0046] Figure 4 A scanning electron microscope image of the carbon particles after high-temperature treatment in Example 4.

[0047] Figure 5 An EDS energy spectrum analysis image of the carbon particles after high-temperature treatment in Example 4.

[0048] Figure 6 A coin cell cycle curve of the lithium-carbon particles in Example 1.

[0049] Figure 7 A coin cell cycle curve of the lithium-carbon particles in Comparative Example 1. DETAILED DESCRIPTION

[0050] The application will be illustrated below in combination with specific examples.

[0051] Example 1

[0052] Polyvinyl alcohol (Aladdin Reagent (Shanghai) Co., Ltd.), polystyrene microspheres (Suzhou Weimai New Material Co., Ltd.), carbon nanotubes (Shandong Dazhan, carbon tube model: GTC-304), silver nanoparticles, diethylenetriamine (Shanghai Yantai Industry Co., Ltd.), isothiazolinone (Aladdin Reagent (Shanghai) Co., Ltd.) and deionized water were uniformly mixed in a mass ratio of 6:6:1:1:9:1:2000 to obtain a slurry with a solid content of 1.2%.

[0053] The slurry was atomized and granulated by a centrifugal atomizer, the centrifugal speed was 500 rpm, and the atomization chamber temperature was set to 250°C.

[0054] The carbon particles prepared by the above centrifugal atomization and granulation were placed in a crucible and subjected to high-temperature treatment under the protection of an inert atmosphere, the high-temperature treatment temperature was 1000°C for 5 hours.

[0055] The carbon particles after high-temperature treatment were mixed with molten lithium metal and stirred uniformly to obtain lithium-carbon particles with a diameter of about 10 microns.

[0056] The obtained lithium-carbon particles were subjected to scanning electron microscope test, and the test results are shown in Figure 2 From Figure 2 it can be seen that the size of the carbon particles is about 10 microns, and the diameter of the silver nanoparticles is about 80 nm. Among them, the carbon nanotube surface is smooth, and the fiber structure is not obvious, which is caused by the wrapping of the amorphous carbon shell layer on the outer layer of the carbon nanotube, and the spherical silver nanoparticles are embedded in the carbon shell on the surface of the carbon nanotube as a whole or in part.

[0057] Example 2

[0058] Polyvinyl alcohol (Aladdin Reagent (Shanghai) Co., Ltd.), polystyrene microspheres (Suzhou Weimai New Material Co., Ltd.), carbon nanotubes (Shandong Dazhan, carbon tube model: GTC-304), isothiazolinone (Aladdin Reagent (Shanghai) Co., Ltd.) and deionized water were uniformly mixed in a mass ratio of 5:7:10:10:500 to obtain a slurry with a solid content of 6%.

[0059] The slurry was atomized and granulated by a two-fluid atomizer, the carrier gas pressure was 0.3 MPa, and the atomization chamber temperature was set to 220°C.

[0060] The carbon particles prepared by the above spray granulation are put into a crucible and high-temperature treated under the protection of inert atmosphere, with a high-temperature treatment temperature of 800°C for 3 hours.

[0061] The carbon particles after high-temperature treatment are mixed with molten metal lithium and stirred uniformly to obtain lithium-carbon particles.

[0062] The obtained lithium-carbon particles are pressed on foamed copper to prepare an electrode containing lithium-carbon particles, and a commercial lithium sheet is assembled into a button cell for specific capacity test. A carbonate electrolyte and a polypropylene separator are used, wherein the carbonate electrolyte is a solute of 1 mol / L LiPF6 and a solvent of EC and EMC (volume ratio of 1:1). The lithium extraction current is 0.2 mA, and the upper limit of the lithium extraction voltage is set to 1.5 V. The specific capacity test results are shown in Figure 3 As can be seen from the figure, the specific capacity of the lithium-carbon particles is about 2750 mAh / g when the lithium extraction voltage of the lithium-carbon particles is 1.5 V.

[0063] Example 3

[0064] Polyvinyl alcohol (Aladdin Reagent (Shanghai) Co., Ltd.), polystyrene microspheres (Suzhou Weima New Material Co., Ltd.), carbon nanotubes (Shandong Dazhan, carbon tube model: GT-205), isothiazolinone (Aladdin Reagent (Shanghai) Co., Ltd.) and deionized water are uniformly mixed in a mass ratio of 5:10:15:10:1960 to obtain a slurry with a solid content of 2%.

[0065] The slurry is atomized and granulated by a two-fluid atomizer, with a carrier gas pressure of 0.3 MPa and an atomization chamber temperature set to 200°C.

[0066] The carbon particles prepared by the above spray granulation are put into a crucible and high-temperature treated under the protection of inert atmosphere, with a high-temperature treatment temperature of 800°C for 2 hours.

[0067] The carbon particles after high-temperature treatment are mixed with molten metal lithium and stirred uniformly to obtain lithium-carbon particles.

[0068] Example 4

[0069] Polyvinyl alcohol (Aladdin Reagent (Shanghai) Co., Ltd.), polystyrene microspheres (Suzhou Weima New Material Co., Ltd.), carbon nanotubes, nanometer titanium dioxide, isothiazolinone (Aladdin Reagent (Shanghai) Co., Ltd.) and deionized water are uniformly mixed in a mass ratio of 5:7:5:5:10:418 to obtain a slurry with a solid content of 5%.

[0070] The slurry is atomized and granulated by a two-fluid atomizer, with a carrier gas pressure of 0.3 MPa and an atomization chamber temperature set to 200°C.

[0071] The carbon particles prepared by the above spray granulation were put into a crucible and high-temperature treated under the protection of inert atmosphere, with a high-temperature treatment temperature of 800°C for 2 hours.

[0072] The carbon particles after high-temperature treatment were subjected to scanning electron microscope test, and the test results are shown in Figure 4 From Figure 4 it can be seen that the granulated carbon particles are spherical, with a diameter of about 10 microns, and the fiber structure on the surface of the carbon particles is not obvious, and the surface of the particles is covered with spherical titanium dioxide nanoparticles. The middle region of the sample was subjected to EDS energy spectrum analysis scanning, and the test results are shown in Figure 5 From the figure, it can be seen that the left figure is the selected region for EDS energy spectrum analysis, which is the middle region, and the right figure is the relative content of elements obtained by EDS energy spectrum analysis, in which the content of carbon element, titanium element and oxygen element is 56.1%, 23.2% and 20.6% respectively. Figure 4

[0073] The carbon particles after high-temperature treatment were mixed with molten lithium metal and stirred uniformly to obtain lithium-carbon particles.

[0074] Comparative Example 1

[0075] Carbon nanotube microspheres were prepared according to the preparation method disclosed in PCT International Application Publication No. WO 2015139660A1 and Chinese Patent Application No. CN 201410395114.0. 10 g of battery-grade lithium metal and 5 g of the carbon nanotube microspheres obtained in the above step were weighed. The lithium metal was first put into a reaction kettle (produced by Shandong Weihai Xinyuan Chemical Machinery Co., Ltd.), and then the carbon nanotube microspheres were put into the reaction kettle. The heating device was started, and the reaction temperature was set to 230°C. When the temperature of the reaction kettle reached 200°C, the stirring device was started, and the material in the reaction kettle was pre-stirred at a stirring speed of 50 r / min (revolutions per minute) for 1 min, and the heating was not stopped during the stirring process. When the temperature of the reaction kettle reached 230°C, the stirring device was started again, and the stirring speed was 500 r / min (revolutions per minute) for 20 minutes. The heating was stopped, and the reaction kettle was naturally cooled to room temperature. The product in the reaction kettle was the prepared lithium metal-porous carbon composite material.

[0076] ​A simulated battery was assembled using the lithium-carbon particles of Example 1 and the metal lithium-skeleton carbon composite material of Comparative Example 1, the particles being pressed against a foam copper as a working electrode, a commercially available lithium sheet as a counter electrode, and a solution of LiPF6 dissolved in a mixed solvent of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC) in a volume ratio of 1:1:1 as an electrolyte. The simulated battery thus obtained was left to stand for 360 minutes on a battery tester (CT-3008, Shenzhen Xinwei Co., Ltd.), and was subjected to a constant current charge (lithium plating) at 1 mA for 1 hour, a constant current discharge (lithium stripping) at 1 mA for 1 hour, and a cycle of charge and discharge for 200 times. After the battery was assembled, a cycle test was performed. The results of the cycle test of Example 1 and Comparative Example 1 are shown in Figs. 1 and 2, respectively. Figure 6 and Figure 7 As can be seen from the figures, the polarization voltage of Comparative Example 1 is greater than that of Example 1, and the polarization voltage of Comparative Example 1 reaches a maximum of 300 mV at the 200th cycle, while the polarization voltage of Example 1 reaches a maximum of 50 mV. Thus, it can be seen that the electrochemical impedance of the electrode surface of Example 1 is smaller, and is more conducive to electrochemical reaction, and can more effectively inhibit the generation and growth of metal lithium dendrites.

[0077] It can be understood that, in the embodiments of the present application, although the lithium-carbon particles and the method for preparing the same are described in detail in combination with specific embodiments, the above is only a description made to meet the legal requirements, and the present application is not limited to the given embodiments. Those skilled in the art can reproduce the lithium-carbon particles and the method for preparing the same according to the disclosure and teachings of the present specification through appropriate operations.

[0078] According to the disclosure and teachings of the present specification, those skilled in the art can make appropriate changes and modifications to the above embodiments. Thus, the present application is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present application should fall within the protection scope of the claims of the present application. In addition, although some specific terms are used in the present specification, these terms are only for convenience of description, and do not constitute any limitation on the present application.

Claims

1. A lithium carbon particle, characterized by, The lithium-carbon particles comprise: The porous particles as the carrier are micron-sized particles with nanometer-sized pores inside and on the surface, which are interwoven by a carbonaceous framework including a crystallized carbon framework and an amorphous carbon layer wrapped on the surface of the crystallized carbon framework, and the non-porous part on the surface of the porous particles is also covered with the amorphous carbon layer, and the amorphous carbon layer on the surface of the particle and the amorphous carbon layer on the surface of the crystallized carbon framework are formed of the same material; and Metallic lithium filled in the pores of the porous particles, The crystallized carbon framework is at least one of carbon nanotubes and carbon fibers; the amorphous carbon layer is a carbonized product of an organic binder, an organic filler and a crosslinking agent blended with the crystallized carbon framework, The organic filler is selected from plastic microparticles, and the plastic includes polypropylene, polyethylene terephthalate or polystyrene.

2. The lithium-carbon particle of claim 1, wherein, The carbonaceous framework also contains nanometer metal particles dispersedly embedded in the amorphous carbon layer.

3. The lithium-carbon particle of claim 1, wherein, The size of the porous particles ranges from 1 micron to 50 microns, and the porosity ranges from 15% to 85%; The thickness of the amorphous carbon layer ranges from 10 nm to 600 nm.

4. A method of producing the lithium carbon particle according to any one of claims 1 to 3, characterized by, The method comprises: Step 1, forming a slurry of an organic binder, a filler including a crystallized carbon framework material and an organic filler, a crosslinking agent and a solvent; Step 2, atomizing and granulating the slurry obtained in step 1; Step 3, heating the material obtained in step 2 at a temperature ranging from 300°C to 1200°C under the protection of an inert atmosphere, and obtaining the porous particles after cooling; Step 4, stirring and mixing the porous particles obtained in step 3 with molten lithium to obtain lithium-carbon particles.

5. The method of claim 4, wherein, The mass ratio of the organic binder, the filler, the crosslinking agent and the solvent is (4-15 parts) : (10-30 parts) : (0.01-20 parts) : (100-7000 parts); The mass proportion of the crystallized carbon framework material in the filler is greater than or equal to 15% to less than 100%.

6. The method of claim 4, wherein The organic binder is selected from the group consisting of polyvinyl alcohol, polyvinylidene fluoride, polybutylene styrene, polystyrene, cyanoacrylate, polyacrylic acid, cyclic ether, polyurethane, methacrylate, epoxy resin, vinyl acetate polymer, polyimide, organosiloxane, polyethylene glycol, polyethylene, polyvinyl chloride, polypropylene, glycerol, hydroxyphenyl ethyl ester, monosaccharide or polysaccharide polymer; The organic filler is selected from plastic microparticles, and the plastic includes polypropylene, polyethylene terephthalate or polystyrene; The crosslinking agent is selected from the group consisting of diethylene triamine and isothiazolinone; The solvent is selected from the group consisting of water, tetrachloroethylene, toluene, turpentine, acetone, methyl acetate, ethyl acetate, pentane, n-hexane, cyclohexane, octane, lemon essence, alcohol, xylene, toluene cyclohexanone, isopropyl alcohol, diethyl ether, propylene oxide, methyl butanone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, acetonitrile, pyridine, phenol, ethylenediamine.

7. The method of claim 4, wherein, The filler also includes metal nanoparticles.

8. The method of claim 4, wherein, The solid content of the slurry formed in step 1 ranges from 0.1% to 12%.

9. The method of claim 4, wherein, The method further comprises: The lithium-carbon particles obtained in step 4 are surface-coated.

10. The method of claim 9, wherein, The substance for surface-coating the lithium-carbon particles obtained in step 4 includes at least one of inorganic nano-oxides, inorganic nano-nitrides, inorganic nano-fluorides, metal salts with oxygen-containing acid radicals, nitrogen-containing organic substances, and sulfur-containing organic substances, wherein the inorganic nano-oxides include aluminum oxide or lithium oxide; the inorganic nano-nitrides include copper nitride or lithium nitride; the inorganic nano-fluorides include lithium fluoride or magnesium fluoride; the metal salts with oxygen-containing acid radicals include zinc sulfate or lithium oxalate; the nitrogen-containing organic substances include polymethylpyrrolidone or melamine; and the sulfur-containing organic substances include sodium polystyrene sulfonate.

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