Lithium battery positive electrode material, preparation method and application thereof

Abstract

This invention provides a lithium-ion battery cathode material, its preparation method, and its application. The raw materials for preparing the cathode include acetylene black, nitric acid solution, cobalt nitrate solution, polytetrafluoroethylene emulsion, water, isopropanol, and copper chloride. This invention uses electrostatic adsorption to uniformly load cobalt ions onto the surface of acetylene black, followed by oxidation treatment to obtain an acetylene black / cobalt tetroxide composite material with uniform dispersion characteristics. Furthermore, by employing a solution impregnation method using fibrous powder materials, and placing them in a copper chloride / isopropanol system for static treatment, not only is spontaneous and uniform adsorption of copper chloride achieved, but the localized catalyst enrichment problem easily caused by traditional mechanical stirring methods is also avoided, significantly improving the dispersion uniformity of the active catalytic components.

Description

Technical Field

[0001] This invention belongs to the field of lithium battery technology, specifically relating to a lithium battery cathode material, its preparation method, and its application. Background Technology

[0002] The lithium thionyl chloride battery is a high-performance primary battery system composed of a lithium metal anode, a carbon cathode, and a lithium tetrachloroaluminate-thionyl chloride non-aqueous electrolyte. A significant feature of this battery is that the thionyl chloride in the electrolyte functions as both a solvent and a reactive material at the cathode, and its wide boiling point range ensures excellent operating temperature adaptability. The carbon cathode provides the electrochemical reaction site as an inert carrier, while the high specific capacity and low electrode potential of the lithium metal anode endow the battery with ultra-high energy density. In particular, the spontaneously formed lithium chloride protective film on the surface of the lithium anode effectively prevents further corrosion by the electrolyte, thus ensuring a long storage life. This ingenious design gives the battery advantages such as a wide temperature range, high energy, and long lifespan.

[0003] The overall reaction of a lithium thionyl chloride battery is 4Li + 2SOCl₂ → 4LiCl + S + SO₂, where the positive electrode reaction is 2SOCl₂ + 4e⁻ → S↓ + SO₂↑ + 4Cl₂. - It occurs on the surface of carbon (acetylene black) particles, proceeding in two steps. The first step is SOCl2 + e-. - →12SCl₂ + SO₂ + 4Cl - The second step is 12SCl2 + e - →12S+Cl - The slow reaction rate in the first step limits the overall reaction rate, resulting in poor high-current discharge performance of lithium thionyl chloride. Currently, the mainstream method is to add copper powder as a catalyst to the positive electrode to improve battery performance; this method has been reported in several patents. However, during the preparation of the positive electrode film, the high-temperature fibrosis process easily leads to oxidation of the copper powder, thereby reducing its catalytic activity. Furthermore, in traditional processes, copper powder is added directly during the positive electrode slurry stage, achieving simple mixing with acetylene black only through mechanical stirring. This method has two main drawbacks: first, due to the significant density difference between copper powder and acetylene black, uniform dispersion is difficult to achieve through mechanical stirring alone, resulting in poor battery product consistency; second, simple physical mixing cannot ensure good electrical contact between copper particles and acetylene black particles, limiting the effective catalytic effect of copper powder and making it difficult for the battery to meet the performance requirements of high-current discharge.

[0004] Therefore, there is an urgent need to develop novel catalysts with excellent antioxidant properties and their composite material preparation processes to achieve uniform dispersion of the catalyst in acetylene black and ensure the formation of a stable conductive network between the catalyst particles and the acetylene black particles. Summary of the Invention

[0005] In view of this, the present invention provides a lithium battery cathode material, its preparation method and application, which effectively solves the problems of uneven catalyst dispersion and poor contact with acetylene black in cathode materials prepared by traditional mechanical mixing methods, and also solves the problem that the catalyst is easily oxidized during the fibrosis process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a lithium battery cathode material, wherein the raw materials for preparing the cathode include: acetylene black, nitric acid solution, cobalt nitrate solution, polytetrafluoroethylene emulsion, water, isopropanol and copper chloride.

[0007] Secondly, the present invention provides a method for preparing the aforementioned lithium battery cathode material, comprising the following steps: S1. Mix acetylene black and nitric acid solution to obtain nitrated acetylene black; S2. Mix the nitrated acetylene black with a cobalt nitrate solution, wash and dry to obtain acetylene black loaded with cobalt ions; S3. The acetylene black loaded with cobalt ions is heated and oxidized sequentially to obtain an acetylene black / cobalt tetroxide composite material. S4. The acetylene black / cobalt tetroxide composite material, polytetrafluoroethylene emulsion, water, and isopropanol are mixed and then subjected to fiberization treatment. S5. After mixing the fibrous raw material with an isopropanol solution containing copper chloride, the mixture is dried to obtain the lithium battery cathode material.

[0008] Preferably, in step S1, the specific steps for mixing acetylene black and nitric acid solution are as follows: the acetylene black and nitric acid solution are mixed, heated under reflux, and allowed to stand to obtain a bottom precipitate. The bottom precipitate is washed, filtered, and washed until the precipitate is neutral. The washed precipitate is then dried to obtain nitrated acetylene black; and / or, In step S1, the mass fraction of nitric acid in the nitric acid solution is 68%.

[0009] Preferably, in step S2, the concentration of the cobalt nitrate solution is 2-2.5 M; and / or, In step S2, the nitrated acetylene black is mixed with a cobalt nitrate solution, and the specific steps of washing and drying are as follows: the nitrated acetylene black is mixed with a cobalt nitrate solution, then filtered and washed with deionized water, and then dried to obtain acetylene black loaded with cobalt ions.

[0010] Preferably, in step S3, the specific steps for heating the cobalt-loaded acetylene black sequentially are as follows: placing the cobalt-loaded acetylene black into an atmosphere furnace, and then heating it at 3°C ​​for 3 minutes... -1The heating rate is increased to 600℃, held at that temperature for 3 hours, and then naturally cooled to room temperature to obtain an acetylene black / cobalt composite material; and / or, In step S3, the specific steps of oxidation are as follows: the acetylene black loaded with cobalt ions is heated, mixed with oxygen, and heated again to obtain an acetylene black / cobalt tetroxide composite material.

[0011] Preferably, in step S3, the mass fraction of cobalt tetroxide in the obtained acetylene black / cobalt tetroxide composite material is 6-8%.

[0012] Preferably, in step S4, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 60%; and / or, In step S4, the specific steps of fiberization are as follows: the acetylene black / cobalt tetroxide composite material, polytetrafluoroethylene emulsion, water, and isopropanol are mixed and dried at 60°C for 3 hours, and then heated to 180°C and kept at that temperature for 20 hours.

[0013] Preferably, in step S5, the mass fraction of copper chloride in the isopropanol solution containing copper chloride is 2%.

[0014] Preferably, in step S5, after mixing the fibrous raw material with the isopropanol solution containing copper chloride, the specific steps of drying are as follows: after mixing the fibrous raw material with the isopropanol solution containing copper chloride, the obtained soaked powder is poured out and pressed into a film with a thickness of 66±2μm by a roller mill, and dried in a forced-air drying oven at 60-80℃ for 12h, the dried film is cut into small films and glued onto a nickel mesh, and then the cover assembly is spot-welded to obtain the lithium battery positive electrode material.

[0015] Thirdly, the present invention provides a lithium battery, including the lithium battery positive electrode material described above, or the lithium battery positive electrode material prepared by the preparation method described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes electrostatic adsorption to adsorb Co 2+ Cobalt tetroxide nanoparticles are uniformly adsorbed onto the surface of acetylene black. Following high-temperature reduction and oxidation, uniformly dispersed cobalt tetroxide nanoparticles are generated in situ on the acetylene black surface, forming an acetylene black / cobalt tetroxide composite material. The stable oxidation state of cobalt tetroxide can withstand the subsequent high-temperature fiberization process. Further, a solution impregnation method is used to uniformly adsorb copper chloride into the fiberized cathode powder, ultimately yielding a composite cathode with highly dispersed catalytic active sites. This method, through a strategy combining chemical adsorption and solution impregnation, effectively solves the problems of uneven catalyst dispersion and poor contact with acetylene black in cathode materials prepared by traditional mechanical mixing methods, while also addressing the issue of catalyst oxidation during fiberization. Attached Figure Description

[0017] Figure 1 The lithium thionyl chloride battery provided in Example 1 of the present invention is shown as a constant resistance discharge curve of 8.2Ω at room temperature. Figure 2 The lithium thionyl chloride battery provided in Comparative Example 1 of this invention has a constant resistance discharge curve of 8.2Ω at room temperature. Figure 3 The lithium thionyl chloride battery provided in Comparative Example 2 of this invention has a constant resistance discharge curve of 8.2Ω at room temperature. Figure 4 The lithium thionyl chloride battery provided in Comparative Example 2 of this invention has a constant resistance discharge curve of 8.2Ω at room temperature. Figure 5 The lithium thionyl chloride battery provided in Comparative Example 4 of this invention has a constant resistance discharge curve of 8.2Ω at room temperature. Figure 6 The lithium thionyl chloride battery provided in Comparative Example 5 of this invention is shown in the constant resistance discharge curve at 8.2Ω at room temperature. Figure 7 The lithium thionyl chloride battery provided in Comparative Example 6 of this invention has a constant resistance discharge curve of 8.2Ω at room temperature. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 This embodiment provides a method for preparing a lithium battery, including the following steps: (1) Mix 600g of acetylene black with 15L of nitric acid, stir and reflux at 120℃ for 12h, let stand for 5h and pour off the supernatant, keeping the bottom precipitate. Pour off the bottom acetylene black and add a large amount of deionized water to dilute the acidity, then filter and wash with deionized water until the filtrate is neutral. Dry the washed product in a forced-air drying oven at 60℃ to obtain nitrated acetylene black.

[0020] (2) Nitro-modified acetylene black was poured into 15L of 2M cobalt nitrate solution and stirred for 24h. Since the nitro group is negatively charged, cobalt ions can be adsorbed through electrostatic adsorption. Then, it was filtered, washed with deionized water, and dried in a forced-air drying oven at 60℃ to obtain acetylene black loaded with cobalt ions.

[0021] (3) Place the cobalt-loaded acetylene black into an atmosphere furnace, and purge the air from the tube with a hydrogen-argon mixture at room temperature for 2 hours. Then, purge the air from the tube at 3°C ​​for 1 minute. -1 The heating rate was increased to 600℃, and after holding at that temperature for 3 hours, it was naturally cooled to room temperature to obtain the acetylene black / cobalt composite material.

[0022] (4) Place the acetylene black / cobalt composite material into an atmosphere furnace, introduce oxygen, and heat at 3°C ​​for 3 min. -1 The acetylene black / cobalt tetroxide composite material was obtained by heating the temperature to 280℃ and holding it for 24 hours. The weight was 639g, and the cobalt tetroxide content in the acetylene black / cobalt tetroxide composite material was 6.5%.

[0023] (5) Pour 535g of acetylene black / cobalt tetroxide composite material, 56g of polytetrafluoroethylene emulsion, 3Kg of deionized water and 230g of isopropanol into a mixing tank and mix evenly. The mass concentration of polytetrafluoroethylene emulsion is 60wt%.

[0024] (6) Place the well-mixed powder into a forced-air drying oven and keep it at 60°C for 3 hours. Then raise the temperature to 180°C and keep it at 20 hours for fiberization treatment.

[0025] (7) Soak the fiberized powder in an isopropanol solution containing 2wt% copper chloride for 15 minutes.

[0026] (8) Pour out the soaked powder and press it into a film with a thickness of 66μm using a roller mill, and dry it in a forced-air drying oven at 60℃ for 12h.

[0027] (9) Cut the dried membrane into small pieces according to the required specifications and stick them on the nickel mesh. Then spot weld the cover assembly to obtain the prepared positive electrode.

[0028] (10) The prepared positive electrode is wound together with lithium sheet and separator, and then the ER18505M battery is obtained through pressing, welding and liquid injection processes.

[0029] Comparative Example 1 This comparative example provides a method for preparing a lithium battery, including the following steps: (1) Pour 500g acetylene black, 56g polytetrafluoroethylene emulsion, 3Kg deionized water and 230g isopropanol into a mixing tank and mix evenly. The mass concentration of polytetrafluoroethylene emulsion is 60wt.

[0030] (2) Place the evenly mixed powder into a forced-air drying oven and keep it at 60°C for 3 hours. Then raise the temperature to 180°C and keep it at 20 hours for fiberization treatment.

[0031] (3) Soak the fiberized powder in isopropanol for 15 minutes.

[0032] (4) Pour out the soaked powder and press it into a film with a thickness of 66μm using a roller press, and dry it in a forced-air drying oven at 60℃ for 12h.

[0033] (5) Cut the dried membrane into small pieces according to the required specifications and stick them on the nickel mesh. Then spot weld the cover assembly to obtain the prepared positive electrode.

[0034] (6) The prepared positive electrode is wound together with the lithium sheet and separator, and then the ER18505M battery is obtained through processes such as pressing, welding and liquid injection.

[0035] Comparative Example 2 This comparative example provides a method for preparing a lithium battery, including the following steps: (1) Pour 500g acetylene black, 56g polytetrafluoroethylene emulsion, 3Kg deionized water and 230g isopropanol into a mixing tank and mix evenly. The mass concentration of polytetrafluoroethylene emulsion is 60wt.

[0036] (2) Place the evenly mixed powder into a forced-air drying oven and keep it at 60°C for 3 hours. Then raise the temperature to 180°C and keep it at 20 hours for fiberization treatment.

[0037] (3) Soak the fiberized powder in an isopropanol solution containing 2wt% copper chloride for 15 minutes.

[0038] (4) Pour out the soaked powder and press it into a film with a thickness of 66μm using a roller press, and dry it in a forced-air drying oven at 60℃ for 12h.

[0039] (5) Cut the dried membrane into small pieces according to the required specifications and stick them on the nickel mesh. Then spot weld the cover assembly to obtain the prepared positive electrode.

[0040] (6) The prepared positive electrode is wound together with the lithium sheet and separator, and then the ER18505M battery is obtained through processes such as pressing, welding and liquid injection.

[0041] Comparative Example 3 This comparative example provides a method for preparing a lithium battery, including the following steps: (1) Pour 500g acetylene black, 35g copper powder, 56g polytetrafluoroethylene emulsion, 3Kg deionized water and 230g isopropanol into a mixing tank and mix evenly. The mass concentration of polytetrafluoroethylene emulsion is 60wt.

[0042] (2) Place the evenly mixed powder into a forced-air drying oven and keep it at 60°C for 3 hours. Then raise the temperature to 180°C and keep it at 20 hours for fiberization treatment.

[0043] (3) Soak the fiberized powder in isopropanol for 15 minutes.

[0044] (4) Pour out the soaked powder and press it into a film with a thickness of 66μm using a roller press, and dry it in a forced-air drying oven at 60℃ for 12h.

[0045] (5) Cut the dried membrane into small pieces according to the required specifications and stick them on the nickel mesh. Then spot weld the cover assembly to obtain the prepared positive electrode.

[0046] (6) The prepared positive electrode is wound together with the lithium sheet and separator, and then the ER18505M battery is obtained through processes such as pressing, welding and liquid injection.

[0047] Comparative Example 4 This comparative example provides a method for preparing a lithium battery, including the following steps: (1) Pour 500g acetylene black, 35g cobalt tetroxide, 56g polytetrafluoroethylene emulsion, 3Kg deionized water and 230g isopropanol into a mixing tank and mix evenly. The mass concentration of polytetrafluoroethylene emulsion is 60wt%.

[0048] (2) Place the evenly mixed powder into a forced-air drying oven and keep it at 60°C for 3 hours. Then raise the temperature to 180°C and keep it at 20 hours for fiberization treatment.

[0049] (3) Soak the fiberized powder in an isopropanol solution containing 2wt% copper chloride for 15 minutes.

[0050] (4) Pour out the soaked powder and press it into a film with a thickness of 66μm using a roller press, and dry it in a forced-air drying oven at 60℃ for 12h.

[0051] (5) Cut the dried membrane into small pieces according to the required specifications and stick them on the nickel mesh. Then spot weld the cover assembly to obtain the prepared positive electrode.

[0052] (6) The prepared positive electrode is wound together with the lithium sheet and separator, and then the ER18505M battery is obtained through processes such as pressing, welding and liquid injection.

[0053] Comparative Example 5 This comparative example provides a method for preparing a lithium battery that is the same as the example, except that the powder obtained after fibrosis is soaked in isopropanol, while the rest of the operation remains unchanged.

[0054] Comparative Example 6 This comparative example provides a method for preparing a lithium battery that is the same as the example, except that the powder obtained after fibrosis is soaked in an isopropanol solution containing 1 wt% copper chloride, while the rest of the operation remains unchanged.

[0055] Comparative Example 7 This comparative example provides a method for preparing a lithium battery that is the same as the example, except that the powder obtained after fibrosis is soaked in an isopropanol solution containing 3 wt% copper chloride, while the rest of the operation remains unchanged.

[0056] Performance Tests and Results In Example 1, we conducted a constant resistance discharge test at room temperature (8.2Ω) on 100 randomly selected battery samples. As shown in Table 1, the test results show that this batch of batteries exhibits excellent performance consistency: the average discharge capacity reaches 2.85Ah, the standard deviation is only 0.06Ah, and the calculated coefficient of variation is as low as 2.1%. Figure 1 The discharge curves of four of the batteries are shown. The discharge plateau voltage is maintained at around 3.5V, and the curves are flat, which fully demonstrates the excellent performance and consistency of the batteries.

[0057] Table 1. Discharge capacity of 100 batteries at 8.2Ω constant resistance at room temperature (unit: Ah)

[0058] In Comparative Example 1, we randomly selected four batteries and conducted an 8.2Ω constant resistance discharge test at room temperature. Figure 2 As shown, due to the absence of any catalyst, the battery voltage plateau was lower at 3.25V, and the average capacity was 2.16Ah, representing a significant performance decrease compared to the example. In Comparative Example 2, since no copper was added, only copper chloride was introduced as a catalyst. Figure 3 As shown, although the battery voltage platform is relatively high, the capacity is significantly reduced compared to the example, with an average capacity of only 2.09 Ah.

[0059] In Comparative Example 3, we used pure copper powder as a catalyst to prepare batteries and randomly selected 100 batteries for 8.2Ω constant resistance discharge testing. The discharge capacity is shown in Table 2. We calculated the average discharge capacity to be 2.75 Ah, the standard deviation to be 0.12, and the coefficient of variation to be 4.3. Compared with Example 1, not only did the average capacity decrease, but the battery capacity also showed obvious dispersion. This capacity difference is likely due to the uneven distribution of copper powder during the electrode preparation process, which led to a large difference in local catalytic efficiency. Figure 4 The discharge curves of the four selected batteries are shown. Analysis of the discharge curves reveals a distinct two-stage voltage plateau: the voltage initially remains around 3.43V, then decreases and stabilizes at another plateau of 3.32V. This phenomenon may be related to the partial oxidation of the copper powder during preparation, leading to a decrease in its catalytic activity.

[0060] Table 2. Discharge capacity of 100 batteries at 8.2Ω constant resistance at room temperature (unit: Ah)

[0061] In Comparative Example 4, we used cobalt tetroxide powder as the main catalyst and introduced copper chloride as an auxiliary catalyst during the isopropanol soaking stage to construct a dual-catalyst system. 100 randomly selected batteries were subjected to 8.2Ω constant resistance discharge testing. The results are shown in Table 3. We calculated the average discharge capacity to be 2.83 Ah, with a standard deviation of 0.11 and a coefficient of variation of 3.9. Compared with Example 1, the average capacity and discharge plateau (…) Figure 5 The performance is comparable, but the discharge capacity is inconsistent. This performance difference is mainly attributed to the uneven dispersion of cobalt tetroxide particles during the preparation of the cathode powder, which leads to differences in the distribution of local catalytic active sites.

[0062] Table 3. Discharge capacity of 100 batteries at 8.2Ω constant resistance at room temperature (unit: Ah)

[0063] The main difference between Comparative Example 5 and Example 1 is that copper chloride catalyst was not added to the isopropanol solution. Test data show that, Figure 6 As shown, the performance of the four randomly selected batteries was basically equivalent to that of Comparative Example 2. This result indicates that adding cobalt tetroxide alone cannot effectively exert a catalytic effect and cannot significantly improve battery performance. Therefore, the battery performance improvement observed in Example 1 is due to the synergistic catalytic effect of cobalt tetroxide and copper chloride, and the combined use of the two catalysts is a key factor in obtaining excellent battery performance.

[0064] Compared to Example 1, Comparative Example 6 differs in that the concentration of the copper chloride solution was reduced from 2 wt% to 1 wt%. Figure 7 As shown, the discharge platforms of the four randomly selected batteries exhibit a clear two-stage characteristic: the voltage of the second discharge platform is significantly lower than that of the first, which is likely due to insufficient copper chloride addition. In Comparative Example 7, when the copper chloride solution concentration increased to 3 wt%, after the fibrous powder was soaked and removed, copper chloride precipitated and adhered to the powder surface as isopropanol evaporated, indicating that the copper chloride concentration was too high. Combining Comparative Examples 6 and 7, it can be concluded that a copper chloride concentration of 2 wt% is the optimal concentration.

[0065] In summary, this invention utilizes an electrostatic adsorption-in-situ oxidation method to prepare acetylene black / cobalt tetroxide composite materials, achieving uniform dispersion of the cobalt tetroxide catalyst in the cathode. Furthermore, a solution impregnation method is used to uniformly adsorb copper chloride into the cathode powder, successfully constructing highly dispersed bicomponent catalytic active sites. This innovative process not only significantly improves the consistency of battery discharge capacity but also, thanks to the intrinsic antioxidant properties of cobalt tetroxide and its synergistic catalytic effect with copper chloride, enhances both the discharge capacity and voltage plateau—two key performance indicators of the battery.

[0066] Unless otherwise specified, all raw materials used in this invention are existing substances that can be purchased directly from the market.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A lithium battery cathode material, characterized in that, The raw materials for preparing the positive electrode include: Acetylene black; nitric acid solution; Cobalt nitrate solution; Polytetrafluoroethylene emulsion; water; Isopropanol; and Copper chloride.

2. The method for preparing the lithium battery cathode material according to claim 1, characterized in that, Includes the following steps: S1. Mix acetylene black and nitric acid solution to obtain nitrated acetylene black; S2. Mix the nitrated acetylene black with a cobalt nitrate solution, wash and dry to obtain acetylene black loaded with cobalt ions; S3. The acetylene black loaded with cobalt ions is heated and oxidized sequentially to obtain an acetylene black / cobalt tetroxide composite material. S4. The acetylene black / cobalt tetroxide composite material, polytetrafluoroethylene emulsion, water, and isopropanol are mixed and then subjected to fiberization treatment. S5. After mixing the fibrous raw material with an isopropanol solution containing copper chloride, the mixture is dried to obtain the lithium battery cathode material.

3. The preparation method according to claim 2, characterized in that, In step S1, the specific steps for mixing acetylene black and nitric acid solution are as follows: The acetylene black and nitric acid solution are mixed, heated under reflux, and allowed to stand to obtain a bottom precipitate. The bottom precipitate is washed, filtered, and washed until the precipitate is neutral. The washed precipitate is then dried to obtain nitrated acetylene black; and / or, In step S1, the mass fraction of nitric acid in the nitric acid solution is 68%.

4. The preparation method according to claim 2, characterized in that, In step S2, the concentration of the cobalt nitrate solution is 2-2.5 M; and / or, In step S2, the nitrated acetylene black is mixed with a cobalt nitrate solution, and the specific steps of washing and drying are as follows: the nitrated acetylene black is mixed with a cobalt nitrate solution, then filtered and washed with deionized water, and then dried to obtain acetylene black loaded with cobalt ions.

5. The preparation method according to claim 2, characterized in that, in step S3, the specific steps of heating the cobalt-loaded acetylene black sequentially are as follows: placing the cobalt-loaded acetylene black into an atmosphere furnace, and then heating it at 3°C ​​for 3 minutes... -1 The heating rate is increased to 600℃, held at that temperature for 3 hours, and then naturally cooled to room temperature to obtain an acetylene black / cobalt composite material; and / or, In step S3, the specific steps of oxidation are as follows: the acetylene black loaded with cobalt ions is heated, mixed with oxygen, and heated again to obtain an acetylene black / cobalt tetroxide composite material.

6. The preparation method according to claim 2, characterized in that, In step S3, the mass fraction of cobalt tetroxide in the acetylene black / cobalt tetroxide composite material is 6-8%.

7. The preparation method according to claim 2, characterized in that, In step S4, the mass fraction of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is 60%; and / or, In step S4, the specific steps of fiberization are as follows: the acetylene black / cobalt tetroxide composite material, polytetrafluoroethylene emulsion, water, and isopropanol are mixed and dried at 60°C for 3 hours, and then heated to 180°C and kept at that temperature for 20 hours.

8. The preparation method according to claim 2, characterized in that, In step S5, the mass fraction of copper chloride in the isopropanol solution containing copper chloride is 2%.

9. The preparation method according to claim 2, characterized in that, In step S5, after mixing the fibrous raw material with an isopropanol solution containing copper chloride, the specific steps of drying are as follows: after mixing the fibrous raw material with the isopropanol solution containing copper chloride, the obtained soaked powder is poured out and pressed into a film with a thickness of 66±2μm by a roller mill, and dried in a forced-air drying oven at 60-80℃ for 12h. The dried film is then cut into small films and glued onto a nickel mesh, and then the cover assembly is spot-welded to obtain the lithium battery positive electrode material.

10. A lithium battery, characterized in that, This includes the lithium battery cathode material as described in claim 1, or the lithium battery cathode material prepared by the preparation method described in any one of claims 2-9.

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