A carbon@natural metal sulfide ore composite material and its preparation method and application

Abstract

The present invention discloses a carbon@natural metal sulfide ore composite material, as well as its preparation method and application. The natural metal sulfide ore is ball-milled in an oxidizing atmosphere to obtain a surface-preoxidized natural metal sulfide ore powder. The surface-preoxidized natural metal sulfide ore powder is mixed with a carbon source and then calcined in a protective atmosphere to obtain the carbon@natural metal sulfide ore composite material. The carbon layer of the composite material forms an interfacial chemical bond with the natural metal sulfide ore, enhancing the bonding between the two and improving stability. This composite material also accelerates interfacial electron migration, resulting in excellent electrochemical performance in lithium batteries, including high capacity and high cycle stability.

Description

Technical Field

[0001] The present invention relates to a carbon@natural metal sulfide ore composite material, a preparation method of the carbon@natural metal sulfide ore composite material, and application of the carbon@natural metal sulfide ore composite material as a negative electrode material for lithium batteries, belonging to the technical field of comprehensive utilization of mineral resources. Background Art

[0002] Faced with increasingly severe energy and environmental crises, the efficient utilization of new energy sources is imperative. Batteries, as important energy carriers, have made remarkable progress in recent years. Among them, ion batteries (lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, etc.) are currently a key energy system of research due to their high volumetric energy density and stable electrochemical performance. As the primary energy carrier in a battery system, the electrochemical properties of electrode materials directly determine the upper limit of battery capacity. Currently, the main synthesis method for electrode materials is to grow and prepare them through atomic-level self-assembly, but these raw materials are mostly derived from high-purity chemicals. Therefore, from the source, battery materials must be obtained through five steps: mining - mineral processing - smelting - chemical processing - synthesis. This is a lengthy process, and the synthesis and preparation of electrode materials produces high levels of "three wastes", making it difficult to truly achieve efficient green energy utilization. Shortening the process from mineral resources to new energy materials would significantly reduce energy consumption and pollution, which is crucial for new energy storage systems.

[0003] Currently, it has been reported that natural metal sulfide ores have high electrochemical activity and exhibit high first charge and discharge when used in energy storage battery systems. However, their cycle stability is poor, making it difficult to truly achieve high-quality utilization of mineral resources. Although carbon coating has been considered an effective method to improve cycle stability, the carbon coating layer often falls off during the composite process with natural minerals, making it difficult to achieve truly complete coating of the mineral material, resulting in continued capacity decay during the cycle. The reason is that after hundreds and thousands of years of free growth of natural minerals, the structure of the material has become increasingly perfect, and the overall energy has evolved towards a lower energy state, that is, towards a high crystallinity, which ultimately leads to fewer defects on the surface of the material. Therefore, how to increase the surface defects of natural mineral materials and further improve the surface precision bonding between mineral materials and carbon-based materials is the key to current research. Summary of the Invention

[0004] To address the problems of existing electrode materials, such as long preparation processes, high pollution levels, and poor cycle stability during use, the first objective of the present invention is to provide a carbon@natural metal sulfide ore composite material. Interfacial chemical bonds are generated between the carbon layer of the composite material and the natural metal sulfide ore, establishing an "interface bridge" between the two materials. This enhances the bonding between the two materials, improves stability, and accelerates electron migration across the interface, ultimately enhancing the electrochemical performance of the material.

[0005] A second object of the present invention is to provide a method for preparing a carbon@natural metal sulfide ore composite material. This preparation method, by performing surface pre-oxidation treatment on the natural metal sulfide ore, is conducive to the construction of interfacial chemical bonds between the carbon coating layer and the natural metal sulfide ore during the subsequent high-temperature calcination process, thereby obtaining a high-capacity, highly stable carbon@natural metal sulfide ore composite material. This method is simple to operate, has a short process, and has high economic value, and is conducive to industrial production and application.

[0006] The third object of the present invention is to provide an application of a carbon@natural metal sulfide ore composite material, which exhibits good electrochemical performance when used as a negative electrode material for lithium batteries.

[0007] In order to achieve the above technical objectives, the present invention provides a method for preparing a carbon@natural metal sulfide ore composite material, which comprises ball milling a natural metal sulfide ore in an oxidizing atmosphere to obtain a surface-preoxidized natural metal sulfide ore powder; mixing the surface-preoxidized natural metal sulfide ore powder with a carbon source, and calcining the mixture under a protective atmosphere to obtain the composite material.

[0008] The key to the technical solution of the present invention is to perform a surface pre-oxidation treatment on the natural metal sulfide ore, ball-mill the natural metal sulfide ore in an oxidizing atmosphere, and use the activation effect of mechanical energy to promote oxygen oxidation of the natural metal sulfide ore surface, so that more defects are generated on the surface of the natural metal sulfide ore. The generation of these defects is conducive to the formation of interfacial chemical bonds between the carbon material and the natural metal sulfide ore during the subsequent high-temperature calcination process, thereby improving the bonding strength between the carbon material and the natural metal sulfide ore, while accelerating electron migration between the interfaces and improving the electrochemical performance of the composite material. Because the surface crystal structure of the natural metal sulfide ore is complete and presents a smooth plane, it is difficult for carbon atoms to form a stable coating when they grow on its surface. The present invention pre-oxidizes the surface of the natural metal sulfide ore, which can, on the one hand, produce defects on the surface of the crystal phase, and on the other hand, a small amount of oxygen elements are attached to the surface of the material. Under the conditions of calcination, the oxygen atoms exhibit strong electronegativity, forming interfacial carbon-oxygen bridge bonds with carbon atoms on the surface of the material, and at the same time forming metal-oxygen bridge bonds with the surface of the bulk mineral material, ultimately forming interfacial metal-oxygen-carbon interfacial chemical bonds. The interfacial chemical bonds strengthen the stability of the coating layer while improving the interfacial electron transmission capacity between different phases.

[0009] As a preferred embodiment, the natural metal sulfide ore includes one of pyrite, molybdenite, stibnite, zinc sulfide ore, and nickel sulfide ore. As a preferred embodiment, the grade of the natural metal sulfide ore is greater than 99%. High-grade natural metal sulfide ore concentrate is easily obtained using existing mineral processing methods.

[0010] As a preferred solution, the oxygen concentration in the oxidizing atmosphere is 20% to 100% by volume. Too low an oxygen concentration makes it difficult to achieve oxidative activation of the metal sulfide ore surface. More preferably, the oxygen concentration in the oxidizing atmosphere is 50% to 100% by volume.

[0011] As a preferred solution, the ball milling conditions are: a rotation speed of 100-1000 rpm and a time of 1-10 hours. If the ball milling speed is too low or the ball milling time is too short, the oxide layer formed on the surface of the metal sulfide ore will be uneven, resulting in uneven subsequent carbon coating. If the ball milling speed is too high or the ball milling time is too long, the sulfur inside the metal sulfide ore will overflow, polluting the environment and reducing the material's specific energy storage capacity. Further preferred ball milling conditions are: a ball milling speed of 500-800 rpm and a ball milling time of 3-8 hours.

[0012] As a preferred embodiment, the carbon source includes at least one of glucose, sucrose, starch, asphalt, and polytetrafluoroethylene, which are common carbon sources in the art.

[0013] As a preferred embodiment, the mass ratio of the carbon source to the metal sulfide ore is 0.05 to 1.0. If the amount of carbon source added is too low, the coating layer on the surface of the metal sulfide ore will be incomplete. If the amount of carbon source added is too high, the energy storage capacity of the composite material will be reduced. The mass ratio of the carbon source to the metal sulfide ore is more preferably 0.1 to 0.3.

[0014] As a preferred solution, the calcination includes two steps: low-temperature calcination and high-temperature calcination; the low-temperature calcination conditions are: calcination at 250°C to 300°C for 2h to 6h, and the high-temperature calcination conditions are: calcination at 400°C to 1000°C for 5h to 8h. The calcination is carried out under a protective atmosphere, and the protective atmosphere can be at least one of nitrogen and argon. Under the low-temperature calcination conditions, the carbon source first melts, which can better mix with the sulfide ore and coat the surface of the material. In addition, in the molten state, the carbon source can undergo organic bridging with the pre-oxidation layer on the surface of the sulfide ore to form a preliminary interfacial chemical bond. If rapid high-temperature calcination is carried out directly, the oxygen element and the carbon element react at the interface, and eventually CO2 is generated and volatilized, making it difficult to form a strong and stable carbon layer coating. During the high-temperature calcination process, if the calcination temperature is too low or the calcination time is too short, the carbonization of the carbon-based material will be incomplete, and the high-activity carbon material coating will not be achieved. If the calcination temperature is too high or the calcination time is too long, the chemical bonds at the material interface will be broken down, resulting in poor structural stability of the composite material. More preferably, the high-temperature calcination temperature is 500°C to 700°C, and the high-temperature calcination time is 5h to 8h.

[0015] The present invention also provides a carbon@natural metal sulfide ore composite material, which is obtained by the preparation method.

[0016] The present invention also provides an application of a carbon@natural metal sulfide ore composite material, which is used as a negative electrode material for a lithium battery.

[0017] Compared with the prior art, the technical solution of the present invention brings the following beneficial technical effects:

[0018] 1) The key to the preparation of the carbon@natural metal sulfide ore composite material of the present invention is to pre-oxidize the surface of the natural metal sulfide ore, which is conducive to the construction of interfacial chemical bonds between the carbon coating layer and the natural metal sulfide ore during the subsequent high-temperature calcination process, thereby obtaining a high-capacity and highly stable carbon@natural metal sulfide ore composite material.

[0019] 2) The preparation method of the carbon@natural metal sulfide ore composite material of the present invention is simple to operate, has a short process, low raw material cost, and high economic value, which is conducive to industrial production and application.

[0020] 3) The carbon@natural metal sulfide ore composite material of the present invention is assembled into a button-type battery and exhibits excellent electrochemical performance, high capacity and high cycle stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the XRD pattern of the molybdenite raw material used in Example 1.

[0022] Figure 2 This is the cyclic stability of the carbon@molybdenite composite material prepared in Example 4.

[0023] Figure 3 This is the XPR graph of the carbon@molybdenite composite material prepared in Example 4.

[0024] Figure 4 This is the charge and discharge platform of the carbon@molybdenite composite material prepared in Example 8. DETAILED DESCRIPTION

[0025] The following examples are used to illustrate the present invention but are not intended to limit the scope of protection of the claims of the present invention.

[0026] The selected high-grade sulfide ore concentrate used in the present invention is obtained by flotation process, and the grade of the sulfide ore is greater than 99%, and can be purchased on the market.

[0027] Example 1 (Comparative Example)

[0028] The selected molybdenite (grade>99%) was placed in an oxidizing atmosphere with an oxygen concentration of 60% for 6 hours, and the obtained material was tested for electrochemical properties.

[0029] Example 2 (Comparative Example)

[0030] The selected molybdenite (grade > 99%) was ball-milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball-milling process was as follows: the ball-milling speed was 600 rpm, and the ball-milling time was 6 hours. The sulfide surface was pre-oxidized and the particle size of the natural sulfide ore material was reduced. The obtained material was then subjected to electrochemical performance testing.

[0031] Example 3 (Comparative Example)

[0032] The selected molybdenite (grade > 99%) powder was uniformly mixed with starch in the liquid phase, with the mass ratio of starch to sulfide ore being 0.2; the obtained mixture was calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material was further calcined at 500°C for 8 hours under an argon atmosphere; the obtained black powder material was a natural sulfide ore composite material with strengthened interfacial chemical bonds, and the electrochemical properties were then tested.

[0033] Example 4 (Comparative Example)

[0034] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0035] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0036] 3. The mixture obtained in the above 2 is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0037] Example 5

[0038] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0039] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0040] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0041] Example 6

[0042] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 20%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0043] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0044] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0045] Example 7

[0046] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 100%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0047] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0048] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0049] Example 8

[0050] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 100 rpm and the ball milling time is 1 hour. The sulfide surface is pre-oxidized and the particle size of the natural sulfide ore material is reduced.

[0051] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0052] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0053] Example 9

[0054] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 1000 rpm and the ball milling time is 10 hours. The sulfide surface is pre-oxidized and the particle size of the natural sulfide ore material is reduced.

[0055] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0056] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0057] Example 10

[0058] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0059] 2. The sulfide ore precursor powder obtained in step 1 above was uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.05;

[0060] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0061] Example 11

[0062] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0063] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 1.0;

[0064] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0065] Example 12

[0066] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0067] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0068] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 400°C for 3 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0069] Example 13

[0070] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0071] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0072] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 1000°C for 12 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0073] Example 14

[0074] 1. The selected pyrite (grade>99%) is ball-milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball-milling process is as follows: the ball-milling speed is 600 rpm and the ball-milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0075] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0076] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0077] Example 15

[0078] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0079] 2. The sulfide ore precursor powder obtained in step 1 above was uniformly mixed with glucose in a liquid phase, with the mass ratio of starch to sulfide ore being 0.2;

[0080] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under a nitrogen atmosphere, and then the material is further calcined at 500°C for 8 hours under a nitrogen atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0081] Example 16

[0082] 1. The selected molybdenite (grade> 99%) is ball milled in an oxidizing atmosphere with an oxygen concentration of 60%. The ball milling process is as follows: the ball milling speed is 600 rpm and the ball milling time is 6 hours to pre-oxidize the sulfide surface and reduce the particle size of the natural sulfide ore material.

[0083] 2. The sulfide ore precursor powder obtained in step 1 above is uniformly mixed with starch in a liquid phase, with a mass ratio of starch to sulfide ore of 0.2;

[0084] 3. The mixture obtained in the above 2 is calcined at 300°C for 2 hours under an argon atmosphere, and then the material is further calcined at 500°C for 8 hours under an argon atmosphere; the obtained black powder material is a natural sulfide mineral composite material with strengthened interfacial chemical bonds, and then the electrochemical performance test is carried out.

[0085] Example 17

[0086] 1. Sample:

[0087] The selected high-grade sulfide ore materials in Examples 1 to 16 are materials with a grade greater than 99% purchased on the market. After the composite material is constructed, the composite material, acetylene black, and sodium hydroxymethyl cellulose (CMC) are added with a certain amount of deionized water in a mass ratio of 8 / 1 / 1 to prepare a uniform slurry. The obtained slurry is coated on a copper foil and then placed in a vacuum oven at 80°C for 12 hours for drying. The obtained electrode is cut by a slicer into small discs with a diameter of 1.2 cm to become the obtained negative electrode material, wherein the copper foil is loaded with more than 1 mg of active substance.

[0088] The obtained negative electrode sheet, electrolyte, lithium sheet, battery shell, separator, etc. are placed in an argon glove box for battery assembly. After sealing, the obtained battery is an assembled button cell.

[0089] Note: All examples adopt the above-mentioned electrode material preparation method.

[0090] 2. Experimental methods

[0091] The obtained button cell was left to stand for 12 h and then placed on a blue electric test channel for electrochemical performance testing, where the current density was set to 0.1 A. -1The voltage range is set to 0.01V ~ 3.0V and the test cycle is 100 cycles. The data obtained is the data directly displayed on the blue electricity tester and can be used directly.

[0092] 3. Test results: see Table 1

[0093] Table 1: Different experimental conditions and test results in each embodiment

[0094]

[0095]

[0096] It can be seen from Table 1 that if the natural metal sulfide ore is not subjected to surface pre-oxidation treatment, it is difficult to form a stable carbon coating layer on its surface, and ball milling activation is the key condition for achieving surface pre-oxidation treatment of natural metal sulfide ore, which is conducive to the formation of interfacial metal-oxygen-carbon interfacial chemical bonds in the subsequent carbon coating process.

Claims

1. A method for preparing a carbon@natural metal sulfide ore composite material, characterized by: The natural metal sulfide ore is placed in an oxidizing atmosphere for ball milling to obtain surface pre-oxidized natural metal sulfide ore powder; the surface pre-oxidized natural metal sulfide ore powder is mixed with a carbon source and then calcined in a protective atmosphere to obtain the product.

2. The method for preparing a carbon@natural metal sulfide ore composite material according to claim 1, characterized in that: The natural metal sulfide ore includes one of pyrite, molybdenite, stibnite, zinc sulfide ore and nickel sulfide ore; and the grade of the natural metal sulfide ore is greater than 99%.

3. The method for preparing a carbon@natural metal sulfide ore composite material according to claim 1, characterized in that: The volume concentration of oxygen in the oxidizing atmosphere is 20% to 100%.

4. The method for preparing a carbon@natural metal sulfide ore composite material according to claim 1 or 3, characterized in that: The ball milling conditions are: a rotation speed of 100 rpm to 1000 rpm, and a time of 1 h to 10 h.

5. The method for preparing a carbon@natural metal sulfide ore composite material according to claim 1, characterized in that: The carbon source includes at least one of glucose, sucrose, starch, asphalt, and polytetrafluoroethylene.

6. The method for preparing a carbon@natural metal sulfide ore composite material according to claim 1 or 5, characterized in that: The mass ratio of the carbon source to the metal sulfide ore is 0.05 to 1.

0.

7. The method for preparing a carbon@natural metal sulfide ore composite material according to claim 1 or 5, characterized in that: The calcination includes two steps: low-temperature calcination and high-temperature calcination. The low-temperature calcination conditions are: calcination at 250°C to 350°C for 2h to 6h, and the high-temperature calcination conditions are: calcination at 400°C to 1000°C for 5h to 8h.

8. A carbon@natural metal sulfide ore composite material, characterized by: The preparation method is obtained by any one of claims 1 to 7.

9. The use of a carbon@natural metal sulfide ore composite material according to claim 8, characterized in that: Used as negative electrode material for lithium batteries.

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