Preparation method for lithium oxide material, and lithium oxide material

Abstract

To provide a method for preparing a lithium oxide material, wherein the prepared lithium oxide material is uniform in particle, high in purity, simple in process, and suitable for application in large-scale industrial production.SOLUTION: Provided is a method for preparing a lithium oxide material, including the following steps: mixing lithium carbonate, a carbon source, and a dispersant in a predetermined proportion, followed by stirring and dispersing, and wet grinding, to obtain an intermediate solution; spray-drying the intermediate solution, to obtain an intermediate; and sintering and pulverizing the intermediate under a protective atmosphere, to obtain a lithium oxide material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the technical field of batteries, and more particularly to a method for producing a lithium oxide material and the lithium oxide material produced by said method. [Background technology]

[0002] As the representative of the secondary battery with the best overall performance at present, the commercialization of lithium-ion batteries can be traced back to the 1990s. After many years of research, lithium iron phosphate and lithium manganese iron phosphate materials have become the technology roadmap with good performance in the field of lithium-ion batteries today.

[0003] Lithium oxide material is an important raw material for lithium-ion battery materials. In the conventional manufacturing process, for example, lithium oxide can be obtained by burning metallic lithium, but metallic lithium needs to be produced by molten salt electrolysis, which is expensive and uneconomical. Alternatively, lithium hydroxide can be oxidized with high concentration hydrogen peroxide by liquid phase method to obtain lithium peroxide, which is then thermally decomposed to obtain lithium oxide, but this requires high equipment requirements, poses safety risks, and requires high purity and size of raw materials. At present, there is no method for producing lithium oxide with a simple process and is economical. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above, the present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the present invention provides a method for producing a lithium oxide material and a lithium oxide material. Based on the carbothermal reduction reaction of lithium carbonate, a carbon source and lithium carbonate are wet-ground to obtain a lithium source paste, and lithium oxide is obtained through spray drying, calcination and post-treatment, so that the material has high purity and uniform particles. In addition, the method for producing the lithium oxide material is simple and suitable for application in large-scale industrial production. [Means for solving the problem]

[0005] Therefore, in a first aspect, according to an embodiment of the present invention, Step S10 of mixing lithium carbonate, a carbon source, and a dispersant in a certain ratio, and performing stirring and dispersion and wet polishing to obtain an intermediate liquid; Step S20 of spray-drying the intermediate liquid to obtain an intermediate; and step S30 of sintering the intermediate body under a protective atmosphere and grinding it to obtain a lithium oxide material.

[0006] Preferably, the carbon source comprises an inorganic carbon source and an organic carbon source.

[0007] Preferably, the inorganic carbon source comprises at least one of conductive carbon black, Super P, Ketjen black, carbon nanotubes, acetylene black, vapor-grown carbon fibers, graphene, and biomass carbon, and the organic carbon source comprises at least one of glucose, sucrose, starch, fructose, maltose, cyclodextrin, citric acid, polyethylene glycol, polyvinyl alcohol, and polyglycerin.

[0008] Preferably, the dispersant comprises one of deionized water, absolute ethanol.

[0009] Preferably, the polishing grain size D50 of the wet polishing is 0.1 μm to 1.0 μm.

[0010] Preferably, in the spray drying process, the spray intake air temperature is 200°C to 280°C, and the exhaust air temperature is 90°C to 120°C.

[0011] Preferably, the protective atmosphere comprises one of a rare gas atmosphere, a vacuum atmosphere.

[0012] Preferably, the rare gas atmosphere contains at least one of nitrogen gas and argon gas.

[0013] Preferably, in the sintering process, the sintering temperature is 700° C. to 1200° C., and the sintering time is 6 hours to 48 hours.

[0014] In a second aspect, embodiments of the present invention further provide a lithium oxide material produced by the method according to the first aspect above.

[0015] The lithium oxide material manufacturing method according to the embodiment of the present invention is based on the carbothermal reduction reaction of lithium carbonate, by wet grinding a carbon source and lithium carbonate to obtain a lithium source paste, and then by spray drying, calcination and post-treatment to obtain lithium oxide, which has high material purity and uniform particles. The process route used in this method is similar to the conventional lithium iron phosphate process route, and the required equipment is basically the same, further reducing the requirements for the process equipment. This manufacturing method has a simple process and low requirements for equipment, making it suitable for large-scale industrial production. [Brief description of the drawings]

[0016] [Figure 1] 1 is a flow chart of a method for producing a lithium oxide material according to one embodiment of the present invention. [Diagram 2] 1 shows XRD spectra of lithium oxide materials according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, the embodiments of the present invention will be described in detail, and examples of the embodiments are shown in the drawings, and the same or similar reference numerals throughout indicate the same or similar parts or parts having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and are for interpreting the present invention, but should not be understood as limiting the present invention.

[0018] The following disclosure provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the following describes specific example components and configurations. It is understood that these are merely exemplary and are not intended to limit the present invention. The present invention may also use repeated reference numerals and / or alphabetical references in different examples. Such repetition is for the purpose of brevity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed. The present invention also provides examples of various specific processes and materials, but one skilled in the art may recognize the applicability of other processes and / or the use of other materials.

[0019] As shown in FIG. 1, in a first aspect, according to an embodiment of the present invention, Step S10 of mixing lithium carbonate, a carbon source, and a dispersant in a certain ratio, and performing stirring and dispersion and wet polishing to obtain an intermediate liquid; Step S20 of spray-drying the intermediate liquid to obtain an intermediate; and step S30 of sintering the intermediate body under a protective atmosphere and grinding it to obtain a lithium oxide material.

[0020] Specifically, the embodiment of the present invention is based on the carbothermal reduction reaction of lithium carbonate, in which carbon generated by decomposition of a carbon source at high temperature reacts with lithium carbonate to generate lithium oxide, and the raw materials required only include lithium carbonate and a carbon source, and no additional raw materials are required, and accordingly, no other products are generated, and no complicated post-treatment process is required.

[0021] Furthermore, the carbon source includes inorganic carbon sources and organic carbon sources.

[0022] In this embodiment, the carbon sources used are a composite carbon source, an inorganic carbon source, and a small molecule organic carbon source. The inorganic carbon source can participate in the high-temperature thermal reduction of lithium carbonate as a reducing agent, and the small molecule organic carbon source can generate a large amount of gas after being decomposed at high temperature, which is advantageous in promoting the sufficient progress of the reduction reaction of lithium carbonate.

[0023] It is understood that if an inorganic carbon source is used alone, the contact between lithium carbonate and the carbon source is incomplete, resulting in insufficient reaction.In addition, if an organic carbon source is used alone, the carbon residue rate of the organic carbon source is low, and the demand for the organic carbon source is large, which not only results in the problem of the paste viscosity being too high during the grinding process, but also generates a large amount of gas during the sintering process, which affects the production of materials.

[0024] Further, the inorganic carbon source includes at least one of conductive carbon black, Super P, Ketjen black, carbon nanotubes, acetylene black, vapor-grown carbon fiber, graphene, and biomass carbon, and the organic carbon source includes at least one of glucose, sucrose, starch, fructose, maltose, cyclodextrin, citric acid, polyethylene glycol, polyvinyl alcohol, and polyglycerin.

[0025] Further, the dispersant includes one of deionized water and absolute ethanol.

[0026] Furthermore, the polishing grain size D50 of the wet polishing is 0.1 μm to 1.0 μm.

[0027] Furthermore, in the spray drying process, the spray intake air temperature is 200°C to 280°C, and the exhaust air temperature is 90°C to 120°C.

[0028] Furthermore, the protective atmosphere includes one of a rare gas atmosphere and a vacuum atmosphere.

[0029] Furthermore, the rare gas atmosphere contains at least one of nitrogen gas and argon gas.

[0030] Furthermore, in the sintering process, the sintering temperature is 700° C. to 1200° C., and the sintering time is 6 hours to 48 hours.

[0031] In a second aspect, embodiments of the present invention further provide a lithium oxide material produced by the method according to the first aspect above.

[0032] The specific steps and effects of the method for preparing a lithium oxide material of the present invention will be described in more detail below with reference to some specific examples, which are not intended to limit the scope of the present invention.

[0033] Example 1 In this example, a lithium oxide material is produced, and specifically, the method includes the following steps (1) to (4).

[0034] (1) 6,000 g of lithium carbonate, 917.07 g of Super P, and 231.79 g of glucose were weighed and added to a ball mill, anhydrous ethanol was added as a dispersant, and the mixture was stirred for 30 minutes. The mixture was then transferred to a sand mill and polished to a paste with a polishing grain size D50 of 0.25 μm, and material a was obtained.

[0035] (2) The material a obtained in step (1) was subjected to a spray drying process to obtain a material b. The spray intake air temperature was set to 220°C, and the exhaust air temperature was set to 100°C.

[0036] (3) The material b obtained in step (2) was sintered under an inert atmosphere to obtain material c. The sintering temperature was 900° C., and the sintering time was 24 h.

[0037] (4) The material c obtained in step (3) was air-flow pulverized to obtain a lithium oxide material.

[0038] Example 2 In this example, a lithium oxide material is produced, and specifically, the method includes the following steps (1) to (4).

[0039] (1) 6,000 g of lithium carbonate, 937 g of Super P, and 678.96 g of polyethylene glycol were weighed and added to a ball mill, anhydrous ethanol was added as a dispersant, and the mixture was stirred for 30 minutes. The mixture was then transferred to a sand mill and polished to a paste with a polishing grain size D50 of 0.32 μm, and material a was obtained.

[0040] (2) The material a obtained in step (1) was subjected to a spray drying process to obtain a material b. The spray intake air temperature was set to 220°C, and the exhaust air temperature was set to 100°C.

[0041] (3) The material b obtained in step (2) was sintered under an inert atmosphere to obtain material c. The sintering temperature was 810° C., and the sintering time was 18 h.

[0042] (4) The material c obtained in step (3) was air-flow pulverized to obtain a lithium oxide material.

[0043] Example 3 In this example, a lithium oxide material is produced, and specifically, the method includes the following steps (1) to (4).

[0044] (1) 6,000 g of lithium carbonate, 927.37 g of ketjen black, and 632.56 g of polyethylene glycol were weighed and added to a ball mill, anhydrous ethanol was added as a dispersant, and the mixture was stirred for 30 minutes. The mixture was then transferred to a sand mill and polished to a paste with a polishing grain size D50 of 0.27 μm, and material a was obtained.

[0045] (2) The material a obtained in step (1) was subjected to a spray drying process to obtain a material b. The spray intake air temperature was set to 220°C, and the exhaust air temperature was set to 100°C.

[0046] (3) The material b obtained in step (2) was sintered under an inert atmosphere to obtain material c. The sintering temperature was 750° C., and the sintering time was 24 h.

[0047] (4) The material c obtained in step (3) was air-flow pulverized to obtain a lithium oxide material.

[0048] Example 4 In this example, a lithium oxide material is produced, and specifically, the method includes the following steps (1) to (4).

[0049] (1) 6,000 g of lithium carbonate, 937.07 g of Super P, and 231.79 g of glucose were weighed and added to a ball mill, anhydrous ethanol was added as a dispersant, and the mixture was stirred for 30 minutes. The mixture was then transferred to a sand mill and polished to a paste with a polishing grain size D50 of 0.23 μm, and material a was obtained.

[0050] (2) The material a obtained in step (1) was subjected to a spray drying process to obtain a material b. The spray intake air temperature was set to 220°C, and the exhaust air temperature was set to 100°C.

[0051] (3) The material b obtained in step (2) was sintered under an inert atmosphere to obtain material c. The sintering temperature was 900° C., and the sintering time was 24 h.

[0052] (4) The material c obtained in step (3) was air-flow pulverized to obtain a lithium oxide material.

[0053] Comparative Example 1 This comparative example produces a lithium oxide material, and specifically includes the following steps (1) and (2).

[0054] (1) 500 g of lithium carbonate was weighed and sintered under an inert atmosphere to obtain material C. The sintering temperature was 850° C. and the sintering time was 36 hours.

[0055] (2) The material c obtained in step (1) was air-flow pulverized to obtain a lithium oxide material.

[0056] Comparative Example 2 In this comparative example, a lithium oxide material is produced, and specifically, the process includes the following steps (1) to (4).

[0057] (1) 6,000 g of lithium carbonate and 960.32 g of Super P were weighed and added to a ball mill, and anhydrous ethanol was added as a dispersant. After stirring for 30 minutes, the mixture was transferred to a sand mill and polished to a paste with a polishing grain size D50 of 0.33 μm, and material a was obtained.

[0058] (2) The material a obtained in step (1) was subjected to a spray drying process to obtain a material b. The spray intake air temperature was set to 220°C, and the exhaust air temperature was set to 100°C.

[0059] (3) The material b obtained in step (2) was sintered under an inert atmosphere to obtain material c. The sintering temperature was 850° C., and the sintering time was 24 h.

[0060] (4) The material c obtained in step (3) was air-flow pulverized to obtain a lithium oxide material.

[0061] Comparative Example 3 The lithium oxide material was purchased from an external source.

[0062] Carbon content detection, lithium content detection, and XRD detection were performed on the lithium oxide materials of Examples 1 to 4 and Comparative Examples 1 to 3. The results of the XRD spectrum are shown in FIG. 2. The carbon content, lithium content, and related components determined by comparison with a standard specimen are shown in Table 1.

[0063] Basic physicochemical parameters of lithium oxide materials [Table 1]

[0064] As can be seen from the above results, the purity of the lithium oxide materials prepared in Examples 1 to 4 is high, close to the purity of lithium oxide materials purchased from outside, and even superior to the purity of lithium oxide materials purchased from outside.

[0065] The process route of this technical means is relatively similar to the conventional lithium iron phosphate process, so the corresponding required equipment is basically the same, the process management is more mature, and it can be easily modified and used on the basis of the conventional production line.

[0066] This technical solution is based on the carbothermal reduction reaction of lithium carbonate, in which carbon generated by the decomposition of a carbon source under high temperature reacts with lithium carbonate to generate lithium oxide, and the required raw materials only include lithium carbonate and a carbon source.

[0067] This technical solution is based on the carbothermal reduction reaction of lithium carbonate, in which carbon generated by the decomposition of a carbon source under high temperature reacts with lithium carbonate to generate lithium oxide, and the carbon sources used are a composite carbon source, an inorganic carbon source and a small molecule organic carbon source, which has the advantages that the inorganic carbon source, as a reducing agent, can participate more in the high temperature thermal reduction of lithium carbonate, and the small molecule organic carbon source can generate a large amount of gas after being decomposed at high temperature, which can promote the sufficient progress of the reduction reaction of lithium carbonate.

[0068] The lithium oxide material manufacturing method according to the embodiment of the present invention is based on the carbothermal reduction reaction of lithium carbonate, by wet grinding a carbon source and lithium carbonate to obtain a lithium source paste, and then by spray drying, calcination and post-treatment to obtain lithium oxide, which has high material purity and uniform particles. The process route used in this method is similar to the conventional lithium iron phosphate process route, and the required equipment is basically the same, further reducing the requirements for the process equipment. This manufacturing method has a simple process and low requirements for equipment, making it suitable for large-scale industrial production.

[0069] In the description of this specification, a description referring to the terms "one embodiment", "several embodiments", "examples", "specific examples", "several examples", etc. means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms are not necessarily limited to the same embodiment or example. And, the specific features, structures, materials or characteristics described can be appropriately combined in any one or more embodiments or examples. In addition, if not mutually inconsistent, a person skilled in the art can combine or combine different embodiments or examples described in this specification and features of different embodiments or examples.

[0070] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and objectives of the present invention, and that the scope of the present invention is limited by the claims and their equivalents.

Claims

1. Step S10 of mixing lithium carbonate, a carbon source, and a dispersant in a certain ratio, and performing stirring and dispersion and wet polishing to obtain an intermediate liquid; Step S20 of spray-drying the intermediate liquid to obtain an intermediate; Sintering the intermediate body under a protective atmosphere and grinding it to obtain a lithium oxide material.

2. A method for producing a lithium oxide material comprising the steps of:

2. The carbon source includes an inorganic carbon source and an organic carbon source. The method for producing a lithium oxide material according to claim 1 .

3. The inorganic carbon source includes at least one of conductive carbon black, Super P, Ketjen black, carbon nanotubes, acetylene black, vapor-grown carbon fiber, graphene, and biomass carbon, and the organic carbon source includes at least one of glucose, sucrose, starch, fructose, maltose, cyclodextrin, citric acid, polyethylene glycol, polyvinyl alcohol, and polyglycerin; The method for producing a lithium oxide material according to claim 2 .

4. The dispersant comprises one of deionized water, absolute ethanol; The method for producing a lithium oxide material according to claim 1 .

5. The polishing grain size D50 of the wet polishing is 0.1 μm to 1.0 μm; The method for producing a lithium oxide material according to claim 1 .

6. In the spray drying process, the spray inlet temperature is 200°C to 280°C, and the exhaust temperature is 90°C to 120°C. The method for producing a lithium oxide material according to claim 1 .

7. The protective atmosphere includes one of a rare gas atmosphere and a vacuum atmosphere. The method for producing a lithium oxide material according to claim 1 .

8. The rare gas atmosphere contains at least one of nitrogen gas and argon gas. The method for producing a lithium oxide material according to claim 7 .

9. The sintering process is performed at a temperature of 700°C to 1200°C for a time of 6h to 48h. The method for producing a lithium oxide material according to claim 8.

10. Produced by the production method according to any one of claims 1 to 9.

1. A lithium oxide material comprising:

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