Preparation method of high-performance cobalt-doped iron sulfide battery material

Abstract

The present application belongs to the field of mineral processing and battery electrode, and relates to a preparation method of high-performance cobalt-doped iron sulfide battery material. The present application takes cobalt-containing pyrite concentrate as raw material, first adopts regrinding-flotation method to process it, then carries out crushing and a large amount of organic matter coating, then carries out spray drying to obtain macromolecule mixed and wrapped cobalt-containing pyrite particles, and finally roasts the particles in inert atmosphere at high temperature to obtain cobalt-containing pyrite-based high-performance battery material. With the aid of natural cobalt doping characteristics, the present application realizes short-process preparation of cobalt-doped iron-based sulfide electrode material, which has the characteristics of high specific capacity, high rate, no volume effect, good stability and long cycle life, and is suitable for application in lithium ion batteries and lithium ion supercapacitors or sodium ion batteries and sodium ion supercapacitors as negative electrode lithium or sodium storage material. The preparation method of the present application is simple and efficient, has few processes, high yield and is suitable for large-scale industrial production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of mineral processing and battery electrode, and relates to a preparation method of high-performance cobalt-doped iron sulfide battery material. BACKGROUND

[0002] Natural pyrite, as the most widely distributed sulfide mineral in the crust, has abundant reserves, low cost, green and clean, and has a high theoretical specific capacity (894 mAh g -1 However, in the "top-down" preparation process of mineral-based materials, the surface is often exposed to low-energy crystal faces with weak electrochemical activity, which leads to slow interface mass transfer rate and poor rate performance, greatly restricting its practical application prospects. Therefore, exploring the improvement of the interface electrochemical activity of pyrite materials will be the key to the practical application of mineral-based energy storage materials.

[0003] The micro-nano crystal structure (microstructure) of the electrode material surface interface directly determines its atomic spatial configuration and electronic structure, and further determines the transmission rate of electrons / ions in the material. In the field of photoelectric catalysis, adjusting the surface interface microstructure of the material through defects (vacancies, doping) is an effective means to improve the conductivity, adsorption performance and catalytic activity of the catalyst. Therefore, introducing hetero-doping into pyrite is expected to improve the interface electrochemical activity and energy storage performance of the material. However, traditional doping processes usually have long process, high cost, and large pollution of by-products, which restricts large-scale preparation.

[0004] At the same time, due to the principle of atomic affinity, natural pyrite often introduces other hetero-atoms such as cobalt and nickel during mineralization, forming a natural doped state. Therefore, it is of great significance to prepare high-performance iron sulfide battery materials with a short process using natural doped pyrite as raw material. SUMMARY

[0005] In order to improve the specific capacity, stability, rate performance of the battery electrode material, and reduce its production cost, the present application provides a preparation method of high-performance cobalt-doped iron sulfide battery material.

[0006] The preparation method of high-performance cobalt-doped iron sulfide battery material provided by the present application comprises the following steps:

[0007] Step 1: taking cobalt-containing pyrite concentrate as raw material, wet ball milling is first carried out to obtain pyrite slurry; the content of pyrite in the cobalt-containing pyrite concentrate is greater than or equal to 82wt%;

[0008] Step 2: adding a pH adjuster to adjust the pH value of the slurry, then sequentially adding a collector and a frother, and carrying out air flotation to obtain purified cobalt-containing pyrite powder; the collector is selected from at least one of black drugs;

[0009] Step 3: The purified cobalt-containing pyrite concentrate obtained in step 2 is mixed with water in a certain proportion and mechanically ground to obtain a pyrite suspension; a water-soluble high molecular weight organic matter is added to the obtained suspension and stirred to dissolve to obtain a slurry for standby use;

[0010] or

[0011] The purified cobalt-containing pyrite concentrate obtained in step 2 is mixed with water and a water-soluble high molecular weight organic matter in proportion, and mechanically ground to obtain a slurry for standby use;

[0012] The grinding speed of mechanical grinding is greater than 500 rpm and the grinding time is greater than 100 min;

[0013] Step 4: spray drying the prepared slurry obtained in step 3 to obtain cobalt-containing pyrite particles coated with a polymer mixture;

[0014] Step 5: calcining the particles obtained in step 4 to obtain the high-performance cobalt-doped iron sulfide battery material.

[0015] Wherein, in step 1, the pyrite content in the cobalt-containing pyrite concentrate is 82wt% to 95wt%, preferably 85wt% to 95wt%, and the cobalt content is 0.05wt% to 0.5wt%, preferably 0.1wt% to 0.3wt%.

[0016] Wherein, in step 1, the particle size of the cobalt-containing pyrite concentrate is 20 μm-100 μm, preferably 30 μm-80 μm.

[0017] In step 1, the wet ball milling product has a fineness of -37 μm, accounting for 70% to 95%, preferably 80% to 90%. The wet ball milling method of the present invention ensures that the product fineness meets the set requirements, and also achieves sufficient dissociation of the cobalt-containing pyrite from impurity minerals during the grinding process, while ensuring that the particle size is within the flotation range, ensuring the effective flotation purification of the cobalt-containing pyrite in the subsequent process.

[0018] Wherein, in step 2, the pH adjuster is one or more of sodium carbonate, sodium hydroxide, potassium hydroxide, lime, etc., and the pH value of the slurry is adjusted to 8-10, preferably 8.5-9.5.

[0019] Wherein, in step 2, the collecting agent is one or more black medicine agents such as butyl ammonium black medicine, aniline black medicine, etc., and the dosage is 100-500g / t, preferably 200-400g / t; the foaming agent is one of No. 2 oil and MIBC, and the dosage is 50-200g / t, preferably 75-150g / t.

[0020] Preferably, in step 2, the collector is composed of butyl ammonium chloride and aniline chloride in a mass ratio of 0.9-1.1:0.9-1.1; further preferably, the collector is composed of butyl ammonium chloride and aniline chloride in a mass ratio of 0.95-1.05:0.95-1.05.

[0021] Wherein, in step 2, the aeration flotation time is 0.5 to 5 minutes, preferably 0.5 to 2 minutes.

[0022] In step 3, the mass ratio of the purified cobalt-containing pyrite concentrate to water is 1:2 to 1:10, the mechanical grinding is a planetary ball mill or a nano-sand mill, the grinding speed is 600 rpm to 1000 rpm, and the grinding time is 2 hours to 10 hours. In the present invention, the control of the grinding speed and time in step (3) is mainly to obtain a fine-grained material, which is conducive to improving the electrical properties of the product.

[0023] Wherein, in step 3, the water-soluble high molecular organic matter is selected from at least one of starch, cellulose, polyvinyl pyrrolidone, polyacrylic acid and other water-soluble high molecular organic matter, and the mass ratio of the high molecular organic matter to the purified cobalt-containing pyrite concentrate is 1:1 to 10:1, preferably 2:1 to 5:1. The selection of water-soluble polymers is mainly based on their availability, low cost and strong dispersibility in water. The dosage control is mainly to ensure that the thickness of the carbon coating on the surface of the final material is appropriate. Too little dosage will result in too thin carbon coating, affecting the cyclic stability of the material. Too much dosage will result in too thick carbon layer, reducing the proportion of active material and reducing specific capacity.

[0024] Preferably, in step 3, the water-soluble high molecular organic matter is selected from at least one of polyvinyl pyrrolidone and carboxymethyl cellulose.

[0025] As a further preference, in step 3, the mass ratio of the high molecular organic matter to the purified cobalt-containing pyrite concentrate is 2 to 3:1.

[0026] Wherein, in step 4, the spray drying temperature is 50°C to 100°C, preferably 70°C to 80°C.

[0027] Wherein, in step 5, the calcination temperature is 400° C. to 800° C., preferably 500° C. to 700° C.; the calcination time is 1 h to 5 h, preferably 2 h to 3 h.

[0028] Principles and advantages

[0029] (1) The present invention provides a method for preparing a high-performance cobalt-doped iron sulfide battery material using natural cobalt-containing pyrite as the main raw material, which has the advantages of large resource reserves, low preparation cost, green and clean, and high specific capacity.

[0030] (2) The present application ingeniously utilizes the cobalt doping characteristics introduced during the pyrite mineralization process, avoiding the problems of long process, high cost, high pollution, etc. in the traditional doping process, greatly reducing the production cost, reducing the preparation process, and having high yield, which is suitable for large-scale industrial production.

[0031] (3) The present application can effectively remove the impurity components such as quartz, mica and calcite which are harmful to the performance of electrode materials in pyrite concentrate through the previous flotation purification, which is beneficial to improve the material performance. At the same time, by adjusting the pH and adding black medicine type collector, cobalt-containing pyrite can be selectively enriched, and the overall doping density of the material can be improved.

[0032] (3) The present application forms a uniform suspension by mixing fine particle level cobalt-containing pyrite and high molecular organic matter, and then forms cobalt-containing pyrite particles uniformly coated with high molecular organic matter through spray drying, which plays an important role in maintaining the structural stability of pyrite electrode materials.

[0033] (4) The high-performance cobalt-doped iron sulfide battery material provided by the present application can be prepared by adjusting the mass ratio of pyrite and high molecular organic matter to prepare cobalt-doped iron sulfide battery materials with different carbon content, which is beneficial to develop high-performance battery materials with high specific capacity, high rate, good stability and long cycle life.

[0034] (5) The high-performance cobalt-doped iron sulfide battery material provided by the present application can be applied to lithium ion batteries, sodium ion batteries, potassium ion batteries, lithium ion supercapacitors, sodium ion supercapacitors and water-based capacitors. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 500mAg -1 Cycling performance diagram of the product obtained in Example 1 in a lithium ion battery at a current density of 500mAg;

[0036] Figure 2 5Ag -1 Cycling performance diagram of the product obtained in Example 1 in a lithium ion battery at a current density of 5Ag;

[0037] Figure 3 500mAg -1 Cycling performance diagram of the product obtained in Example 1 in a sodium ion battery at a current density of 500mAg;

[0038] Figure 4 5Ag -1 Cycling performance diagram of the product obtained in Example 1 in a sodium ion battery at a current density of 5Ag. DETAILED DESCRIPTION

[0039] Example 1

[0040] High-performance cobalt-doped iron sulfide battery materials were prepared using cobalt-containing pyrite concentrate with a pyrite content of 88 wt%, a cobalt content of 0.19 wt%, and an average particle size of 45 μm as raw materials. The specific steps are as follows:

[0041] Step 1: Wet ball mill the cobalt-containing pyrite concentrate to a fineness of -37 μm, accounting for 85%;

[0042] Step 2: Sodium carbonate was added to adjust the pH value of the slurry to 9.0, followed by the sequential addition of 250 g / t of ammonium butylate and 100 g / t of MIBC, followed by aeration and flotation for 1 min. The flotation concentrate was collected to obtain high-purity cobalt-containing pyrite concentrate.

[0043] Step 3: The high-purity cobalt-containing pyrite concentrate obtained in step 2 was mixed with pure water in a mass ratio of 1:5, and subjected to planetary ball milling for 5 h (ball milling speed of 600 rpm) to obtain a pyrite suspension;

[0044] Step 4: Add polyvinyl pyrrolidone (2 times the mass of high-purity cobalt-containing pyrite concentrate) to the suspension obtained in step 3, and stir to dissolve;

[0045] Step 5: spray drying the suspension containing cobalt-containing pyrite particles and polyvinyl pyrrolidone obtained in step 4 at a drying temperature of 75° C. to obtain cobalt-containing pyrite particles mixed and coated with polyvinyl pyrrolidone;

[0046] Step 6: calcine the particles obtained in step 5 at 500° C. for 2 h in a nitrogen atmosphere. The product obtained after calcination is a high-performance cobalt-doped iron sulfide battery material.

[0047] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 1149 mAh g -1 The specific capacity ( Figure 1 ), at a current density of 5000mAg -1 After 2000 cycles, 843 mAh g -1 The specific capacity ( Figure 2 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 733mAh g -1 The specific capacity ( Figure 3 ), at a current density of 5000mAg -1 Under this condition, 514mAh g can be obtained after 2000 cycles. -1 The specific capacity ( Figure 4 ).

[0048] Example 1-1

[0049] Other conditions are the same as those in Example 1, except that:

[0050] Step 2: Sodium carbonate was added to adjust the pH value of the pulp to 9.0, followed by the sequential addition of 125 g / t of butyl ammonium chloride, 125 g / t of aniline chloride, and 100 g / t of MIBC. The mixture was aerated and flotated for 1 min. The flotation concentrate was collected to obtain high-purity cobalt-containing pyrite concentrate.

[0051] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 1204mAh g -1 The specific capacity at a current density of 5000mA g -1 After 2000 cycles, 826 mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 754 mAh g -1 The specific capacity at a current density of 5000mAg -1 After 2000 cycles, 538mAh g -1 Specific capacity.

[0052] Example 1-2

[0053] Other conditions are the same as those in Example 1, except that:

[0054] Step 2: Sodium carbonate was added to adjust the pH value of the pulp to 9.0, followed by the sequential addition of 100 g / t of butyl ammonium chloride, 150 g / t of aniline chloride, and 100 g / t of MIBC. The mixture was aerated and flotated for 1 min. The flotation concentrate was collected to obtain high-purity cobalt-containing pyrite concentrate.

[0055] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 1098mAh g -1 The specific capacity at a current density of 5000mA g -1 After 2000 cycles, 813 mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 741 mAh g -1 The specific capacity at a current density of 5000mAg -1 After 2000 cycles, 522mAh g -1 Specific capacity.

[0056] Examples 1-3

[0057] Other conditions are the same as those in Example 1, except that:

[0058] Step 2: Sodium carbonate was added to adjust the pH value of the pulp to 9.0, followed by the sequential addition of 50 g / t of butylammonium nitrofuran, 200 g / t of aniline nitrofuran, and 100 g / t of MIBC, followed by aeration and flotation for 1 min. The flotation concentrate was collected to obtain high-purity cobalt-containing pyrite concentrate.

[0059] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 1184 mAh g -1 The specific capacity at a current density of 5000mA g -1 After 2000 cycles, 855mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 741 mAh g -1 The specific capacity at a current density of 5000mAg -1 Under the condition of 2000 cycles, 520mAh g -1 Specific capacity.

[0060] Examples 1-4

[0061] Other conditions are the same as those in Example 1, except that:

[0062] Step 2: Sodium carbonate was added to adjust the pH value of the pulp to 9.0, followed by the sequential addition of 250 g / t of aniline black and 100 g / t of MIBC, followed by aeration and flotation for 1 min. The flotation concentrate was collected to obtain high-purity cobalt-containing pyrite concentrate.

[0063] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 1162 mAh g -1 The specific capacity at a current density of 5000mA g -1 After 2000 cycles, 860mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 743 mAh g -1 The specific capacity at a current density of 5000mAg -1 After 2000 cycles, 508mAh g -1 Specific capacity.

[0064] Examples 1-5

[0065] Other conditions are the same as those in Example 1, except that:

[0066] Step 3: The high-purity cobalt-containing pyrite concentrate obtained in step 2 and pure water are in a mass ratio of 1:5, and the mass ratio of the high-purity cobalt-containing pyrite concentrate obtained in step 2 and polyvinyl pyrrolidone is 1:2. The high-purity cobalt-containing pyrite concentrate obtained in step 2, pure water, and polyvinyl pyrrolidone are weighed, and all the weighed substances are added to a planetary ball mill for 5 hours to obtain a spare slurry (the ball mill speed is 600 rpm); the spare slurry is spray dried to obtain polymer-mixed cobalt-containing pyrite particles.

[0067] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 1079 mAh g -1 The specific capacity at a current density of 5000mA g -1 After 2000 cycles, 829 mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 708mAh g -1 The specific capacity at a current density of 5000mAg -1 Under this condition, 523mAh g can be obtained after 2000 cycles. -1 Specific capacity.

[0068] Example 2

[0069] High-performance cobalt-doped iron sulfide battery materials were prepared using cobalt-containing pyrite concentrate with a pyrite content of 94wt%, a cobalt content of 0.26wt%, and an average particle size of 38μm as raw materials. The specific steps are as follows:

[0070] Step 1: firstly wet-ball mill the cobalt-containing pyrite concentrate to a fineness of -37 μm accounting for 80%;

[0071] Step 2: Lime was added to adjust the pH value of the pulp to 9.5, followed by the sequential addition of 350 g / t of aniline black and 150 g / t of No. 2 oil, followed by aeration and flotation for 2 minutes. The flotation concentrate was collected to obtain high-purity cobalt-containing pyrite concentrate.

[0072] Step 3: The high-purity cobalt-containing pyrite concentrate obtained in step 2 was mixed with pure water in a mass ratio of 1:2, and the mixture was milled by nano-grinding for 10 h (at a speed of 1000 rpm) to obtain a pyrite suspension;

[0073] Step 4: Add starch 5 times the mass of high-purity cobalt-containing pyrite concentrate to the suspension obtained in step 3, and stir to dissolve;

[0074] Step 5: spray drying the suspension containing cobalt-containing pyrite particles and starch obtained in step 4 at a drying temperature of 70° C. to obtain cobalt-containing pyrite particles coated with starch;

[0075] Step 6: calcine the particles obtained in step 5 at 600° C. for 3 h in an argon atmosphere. The product obtained after calcination is a high-performance cobalt-doped iron sulfide battery material.

[0076] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 1008mAh g -1 The specific capacity at a current density of 5000mA g -1 After 2000 cycles, 827mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 715mAh g -1 The specific capacity at a current density of 5000mAg -1 After 1000 cycles, 497 mAh g -1 Specific capacity.

[0077] Example 3

[0078] High-performance cobalt-doped iron sulfide battery materials were prepared using cobalt-containing pyrite concentrate with a pyrite content of 85wt%, a cobalt content of 0.12wt%, and an average particle size of 74μm as raw materials. The specific steps are as follows:

[0079] Step 1: Wet ball mill the cobalt-containing pyrite concentrate to a fineness of -37 μm, accounting for 90%;

[0080] Step 2: Sodium hydroxide was added to adjust the pH value of the pulp to 8.8, followed by the sequential addition of 200 g / t of butyl ammonium chloride and 75 g / t of No. 2 oil, followed by aeration and flotation for 0.5 min. The flotation concentrate was collected to obtain high-purity cobalt-containing pyrite concentrate;

[0081] Step 3: The high-purity cobalt-containing pyrite concentrate obtained in step 2 was mixed with pure water in a mass ratio of 1:10, and a pyrite suspension was obtained by planetary ball milling for 4 h (the ball milling speed was 800 rpm);

[0082] Step 4: Add carboxymethyl cellulose in an amount three times the mass of high-purity cobalt-containing pyrite concentrate to the suspension obtained in step 3, and stir to dissolve;

[0083] Step 5: spray drying the suspension containing cobalt-containing pyrite particles and carboxymethyl cellulose obtained in step 4 at a drying temperature of 80° C. to obtain cobalt-containing pyrite particles mixed and coated with carboxymethyl cellulose;

[0084] Step 6: calcine the particles obtained in step 5 at 700° C. for 2.5 h in an argon atmosphere. The product obtained after calcination is a high-performance cobalt-doped iron sulfide battery material.

[0085] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 1241 mAh g -1 The specific capacity at a current density of 5000mA g -1 After 2000 cycles, 793 mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 744 mAh g -1 The specific capacity at a current density of 5000mAg -1 After 1000 cycles, 508mAh g -1 Specific capacity.

[0086] Comparative Example 1

[0087] The material preparation steps were the same as those in Example 1, except that the raw materials were replaced with cobalt-containing pyrite concentrate with a pyrite content of 80 wt%, a cobalt content of 0.02 wt%, and an average particle size of 60 μm. The prepared battery material was used as a negative electrode material for lithium-ion batteries at a current density of 500 mAg -1 After 100 cycles, 1026 mAh g -1 The specific capacity at a current density of 5000mA g -1 Under this condition, 567mAh g can be obtained after 2000 cycles. -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 689mAh g -1 The specific capacity at a current density of 5000mAg -1 After 1000 cycles, 374 mAh g -1 Specific capacity.

[0088] A comparison found that when the cobalt content in the raw materials was low, the rate performance of the prepared battery material was poor and the specific capacity was low during large current cycling.

[0089] Comparative Example 2

[0090] The raw materials and other preparation steps were the same as those in Example 1, except that the collector in step 2 was replaced by butyl xanthate. When the prepared battery material was used as the negative electrode material of lithium-ion battery, the current density was 500 mA g -1 After 100 cycles, 956 mAh g -1 The specific capacity at a current density of 5000mA g -1 After 2000 cycles, 576 mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 624 mAh g -1 The specific capacity at a current density of 5000mAg -1 After 1000 cycles, 352mAh g -1 Specific capacity.

[0091] A comparison found that after the black drug collector was replaced with butyl xanthate during the preparation process, the purity of the cobalt-containing pyrite concentrate obtained was lower, affecting the subsequent battery material performance.

[0092] Comparative Example 3

[0093] Other conditions are the same as those in Example 1, except that:

[0094] Step 4: Add polyvinyl pyrrolidone (0.5 times the mass of high-purity cobalt-containing pyrite concentrate) to the suspension obtained in step 3, and stir to dissolve;

[0095] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 732 mAh g -1 The specific capacity at a current density of 5000mAg -1 After 2000 cycles, 263 mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 408mAh g -1 The specific capacity at a current density of 5000mA g -1 Under the condition of 2000 cycles, 133mAh g -1 Specific capacity.

[0096] Comparative Example 4

[0097] Other conditions are the same as those in Example 1, except that:

[0098] Step 3: The high-purity cobalt-containing pyrite concentrate obtained in step 2 and pure water are in a mass ratio of 1:5, and the mass ratio of the high-purity cobalt-containing pyrite concentrate obtained in step 2 and polyvinyl pyrrolidone is 1:2. The high-purity cobalt-containing pyrite concentrate obtained in step 2, pure water, and polyvinyl pyrrolidone are weighed, and all the weighed materials are added to the mixing equipment and mixed evenly at a low speed (speed of 200 rpm); the reserved slurry is spray dried to obtain polymer-mixed cobalt-containing pyrite particles.

[0099] When it is used as the negative electrode material of lithium-ion batteries, the current density is 500mA g -1 After 100 cycles, 861mAh g -1 The specific capacity at a current density of 5000mAg -1 After 2000 cycles, 455mAh g -1 When used as negative electrode material for sodium ion batteries, the current density is 500mAg -1 After 100 cycles, 518 mAh g -1 The specific capacity at a current density of 5000mA g -1 After 1000 cycles, 337mAh g -1 Specific capacity.

Claims

1. A method for preparing high-performance cobalt-doped iron sulfide battery material, characterized in that: The preparation method comprises the following steps: Step 1: Using cobalt-containing pyrite concentrate as a raw material, wet ball milling the concentrate to obtain a pyrite slurry; the cobalt-containing pyrite concentrate has a pyrite content of 82 wt% to 95 wt% and a cobalt content of 0.05 wt% to 0.5 wt%; Step 2: adding a pH adjuster to adjust the pH value of the pulp, then sequentially adding a collector and a frother, and aerating flotation to obtain purified cobalt-containing pyrite concentrate; the collector is selected from at least one of black powder; Step 3: mixing the purified cobalt-containing pyrite concentrate obtained in step 2 with water in a mass ratio of 1:2 to 1:10, and mechanically grinding to obtain a pyrite suspension; adding a water-soluble high molecular weight organic matter to the obtained suspension, stirring and dissolving, to obtain a slurry for standby use; or The purified cobalt-containing pyrite concentrate obtained in step 2 is mixed with water and a water-soluble high molecular weight organic matter in proportion, and mechanically ground to obtain a slurry for standby use; The grinding speed of mechanical grinding is greater than 500 rpm and the grinding time is greater than 100 min; In step 3, the mechanical grinding is a planetary ball mill or a nano sand mill, the grinding time is 2h-10h, the water-soluble macromolecular organic matter is selected from at least one of starch, cellulose, polyvinyl pyrrolidone, and polyacrylic acid, and the mass ratio of the macromolecular organic matter to the purified cobalt-containing pyrite concentrate is 1:1-10:1; Step 4: spray drying the prepared slurry obtained in step 3 to obtain cobalt-containing pyrite particles coated with a polymer mixture; Step 5: calcining the particles obtained in step 4 to obtain the high-performance cobalt-doped iron sulfide battery material.

2. The method for preparing a high-performance cobalt-doped iron sulfide battery material according to claim 1, characterized in that: In step 1, the pyrite content in the cobalt-containing pyrite concentrate is 85wt%~95wt%, and the cobalt content is 0.1wt%~0.3wt%.

3. The method for preparing a high-performance cobalt-doped iron sulfide battery material according to claim 1, characterized in that: In step 1, the particle size of the cobalt-containing pyrite concentrate is 20 μm-100 μm.

4. The method for preparing a high-performance cobalt-doped iron sulfide battery material according to claim 1, characterized in that: In step 2, the pH adjuster is one or more of sodium carbonate, sodium hydroxide, potassium hydroxide, and lime, and the pH value of the slurry is adjusted to 8-10.

5. The method for preparing a high-performance cobalt-doped iron sulfide battery material according to claim 1, characterized in that: In step 2, the collecting agent is one or more of butyl ammonium nitropropane and aniline nitropropane, and the dosage is 100-500 g / t; the foaming agent is one of No. 2 oil and MIBC, and the dosage is 50-200 g / t.

6. The method for preparing a high-performance cobalt-doped iron sulfide battery material according to claim 1, characterized in that: In step 2, the aeration flotation time is 0.5 to 5 minutes.

7. The method for preparing a high-performance cobalt-doped iron sulfide battery material according to claim 1, characterized in that: In step 3, the mass ratio of the high molecular organic matter to the purified cobalt-containing pyrite concentrate is 2:1 to 5:

1.

8. The method for preparing a high-performance cobalt-doped iron sulfide battery material according to claim 1, characterized in that: In step 4, the spray drying temperature is 50°C to 100°C.

9. The method for preparing a high-performance cobalt-doped iron sulfide battery material according to claim 1, characterized in that: In step 5, the calcination temperature is 400° C. to 800° C., and the calcination time is 1 h to 5 h.

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