A method for preparing a lithium oxide material, a lithium oxide material

Abstract

The application provides a preparation method of a lithium oxide material, comprising the following steps: mixing lithium carbonate, a carbon source and a dispersing agent according to a certain proportion, stirring and dispersing, wet grinding to obtain an intermediate liquid; performing spray drying on the intermediate liquid to obtain an intermediate; sintering the intermediate in a protective atmosphere, crushing to obtain the lithium oxide material. The prepared lithium oxide particles are uniform and high in purity. The process flow is simple, and the method is suitable for large-scale industrial production. The application further provides the prepared lithium oxide material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, and more particularly to a preparation method of a lithium oxide material and the lithium oxide material prepared by the preparation method. BACKGROUND

[0002] As the representative of the secondary battery with the best comprehensive performance, the commercialization of the lithium ion battery can be traced back to the 1990s. After years of research, lithium iron phosphate and lithium manganese iron phosphate materials have become a good technical route in the field of lithium ion batteries.

[0003] Among them, the lithium oxide material is an important raw material of the lithium ion battery material. The existing preparation process, such as obtaining lithium oxide by burning metal lithium, however, the metal lithium needs to be generated by molten salt electrolysis, which is high in process cost and uneconomical; or using high-concentration hydrogen peroxide to oxidize lithium hydroxide to obtain lithium peroxide, which requires high equipment requirements, has safety risks, and has high requirements for the purity and size of raw materials. At present, there is a lack of a simple and economical preparation method of lithium oxide. SUMMARY

[0004] In view of the above, the present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a preparation method of a lithium oxide material and the lithium oxide material. Based on the carbonthermal reduction of lithium carbonate reaction, a lithium source slurry is obtained by liquid phase grinding of a carbon source and lithium carbonate, and after spray drying, calcination and post-treatment, lithium oxide is obtained, which has high material purity and uniform particles. At the same time, the preparation method of the lithium oxide material has a simple process flow and is suitable for large-scale industrial production.

[0005] To this end, in a first aspect, the embodiments of the present application provide a preparation method of a lithium oxide material, which comprises:

[0006] S10, mixing lithium carbonate, a carbon source and a dispersant in a certain proportion, stirring and dispersing, and wet grinding to obtain an intermediate liquid;

[0007] S20, spray drying the intermediate liquid to obtain an intermediate;

[0008] S30, sintering and crushing the intermediate in a protective atmosphere to obtain the lithium oxide material.

[0009] Preferably, the carbon source comprises inorganic carbon source and organic carbon source.

[0010] Preferably, the inorganic carbon source comprises at least one of conductive carbon black, Super P, Ketjen black, carbon nanotube, acetylene black, vapor grown carbon fiber, graphene, biomass carbon; the organic carbon source comprises at least one of glucose, sucrose, starch, fructose, maltose, cyclodextrin, citric acid, polyethylene glycol, polyvinyl alcohol, glycerol.

[0011] Preferably, the dispersant comprises one of deionized water, anhydrous ethanol.

[0012] Preferably, the grinding granularity D50 of the wet grinding is 0.1-1.0 μm.

[0013] Preferably, the spray-inlet temperature of the spray drying process is 200-280℃, and the outlet temperature is 90-120℃.

[0014] Preferably, the protective atmosphere comprises one of a rare gas atmosphere, a vacuum atmosphere.

[0015] Preferably, the rare gas atmosphere comprises at least one of nitrogen, argon.

[0016] Preferably, the sintering temperature of the sintering process is 700-1200℃, and the sintering time is 6-48h.

[0017] In a second aspect, the present application also provides a lithium oxide material prepared by the preparation method of the first aspect.

[0018] The preparation method of the lithium oxide material provided by the embodiments of the present application is based on the carbothermal reduction of lithium carbonate reaction, and a lithium source slurry is obtained by liquid phase grinding of a carbon source and lithium carbonate. After spray drying, calcination and post-processing, lithium oxide is prepared. The material has high purity and uniform particles. In addition, the process route adopted by the method has similarities with the existing lithium iron phosphate process route, and the required equipment is basically the same, further reducing the equipment demand of the process. The process flow of the preparation method is simple, the equipment demand is low, and it is suitable for large-scale industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The preparation method of the lithium oxide material provided by an embodiment of the present application is shown in the flow chart;

[0020] Figure 2 The XRD spectra of the lithium oxide materials of embodiments 1-4 and comparative examples 1-3 of the present application are shown in the following table. DETAILED DESCRIPTION

[0021] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like component have the same or similar designations. The embodiments described below are presented by way of example to explain the present application, and are not intended to limit the present application.

[0022] The disclosure that follows provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplicity, the elements of the embodiments in the following detailed description are not necessarily drawn to scale and the disclosure is intended to embrace all alterations, equivalents, and substitutes for elements in the following detailed description that are encompassed by the scope of the present application. Furthermore, the present application can be used in different examples that are not necessarily mutually exclusive, but can be combined in different ways. Furthermore, the present application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize that other processes can be applied and / or other materials can be used.

[0023] Reference will now be made to Figure 1 In a first aspect, the embodiments of the present application provide a preparation method of a lithium oxide material, the preparation method comprising:

[0024] S10, mixing lithium carbonate, a carbon source and a dispersant in a certain proportion, and stirring and dispersing, and wet grinding to obtain an intermediate liquid;

[0025] S20, spray drying the intermediate liquid to obtain an intermediate;

[0026] S30, sintering and crushing the intermediate in a protective atmosphere to obtain the lithium oxide material.

[0027] Specifically, the embodiments of the present application are based on a carbothermal reduction of lithium carbonate reaction, and carbon generated by decomposition of the carbon source at high temperature reacts with lithium carbonate to produce lithium oxide. The required raw materials only include lithium carbonate and a carbon source, without additional raw materials, and accordingly, no other products are generated, and no complex post-processing process is required.

[0028] Further, the carbon source includes inorganic carbon sources and organic carbon sources.

[0029] In the embodiments, the carbon source used is a composite carbon source, and the inorganic carbon source and the small-molecule organic carbon source. The advantage is that the inorganic carbon source can act as a reducing agent and participate in the high-temperature thermal reduction of lithium carbonate in large quantities, and the small-molecule organic carbon source generates a large amount of gas after high-temperature decomposition, which can promote the full progress of the lithium carbonate reduction reaction.

[0030] It is understandable that using only an inorganic carbon source would result in incomplete contact between lithium carbonate and the carbon source, leading to insufficient reaction. Furthermore, using only an organic carbon source would result in excessively high slurry viscosity during grinding due to its lower residual carbon content and larger demand. Additionally, the sintering process would generate a large amount of gas, affecting material preparation.

[0031] Furthermore, the inorganic carbon source includes at least one of conductive carbon black, Super P, Ketjen black, carbon nanotubes, acetylene black, vapor-grown carbon fibers, graphene, and biomass carbon; the organic carbon source includes at least one of glucose, sucrose, starch, fructose, maltose, cyclodextrin, citric acid, polyethylene glycol, polyvinyl alcohol, and polyglycerol.

[0032] Furthermore, the dispersant includes one of deionized water and anhydrous ethanol.

[0033] Furthermore, the grinding particle size D50 of the wet grinding is between 0.1 μm and 1.0 μm.

[0034] Furthermore, the spray inlet temperature in the spray drying process is 200℃-280℃, and the outlet temperature is 90℃-120℃.

[0035] Furthermore, the protective atmosphere includes one of a rare gas atmosphere and a vacuum atmosphere.

[0036] Furthermore, the rare gas atmosphere includes at least one of nitrogen and argon.

[0037] Furthermore, the sintering temperature of the sintering process is between 700℃ and 1200℃, and the sintering time is between 6h and 48h.

[0038] Secondly, embodiments of the present invention also provide a lithium oxide material, which is prepared by the preparation method described in the first aspect above.

[0039] The following detailed description, in conjunction with some specific embodiments, further illustrates the specific process and effects of the preparation method of lithium oxide material using the present invention, but does not limit the scope of protection of the present invention.

[0040] Example 1

[0041] This embodiment prepares a lithium oxide material, specifically including the following steps:

[0042] (1) Weigh 6000g lithium carbonate, 917.07g Super P and 231.79g glucose, add them to a ball mill, add anhydrous ethanol as a dispersant, stir for 30 minutes and then transfer to a sand mill for grinding so that the particle size D50 of the slurry is 0.25um, and obtain material a;

[0043] (2) The material a obtained in step (1) is subjected to spray drying treatment to obtain material b; the spray inlet temperature is 220°C, and the outlet temperature is 100°C;

[0044] (3) The material b obtained in step (2) is sintered under an inert atmosphere to obtain material c; the sintering temperature is 900°C, and the sintering time is 24h;

[0045] (4) The material c obtained in step (3) is subjected to jet milling to obtain a lithium oxide material.

[0046] Example 2

[0047] The lithium oxide material is prepared according to the following steps:

[0048] (1) 6000g of lithium carbonate, 937g of Super P, and 678.96g of polyethylene glycol are weighed and added to a ball mill, anhydrous ethanol is added as a dispersant, and stirring is performed for 30min, and then the slurry is ground in a sand mill to obtain a material a with a grinding particle size D50 of 0.32um;

[0049] (2) The material a obtained in step (1) is subjected to spray drying treatment to obtain material b; the spray inlet temperature is 220°C, and the outlet temperature is 100°C;

[0050] (3) The material b obtained in step (2) is sintered under an inert atmosphere to obtain material c; the sintering temperature is 810°C, and the sintering time is 18h;

[0051] (4) The material c obtained in step (3) is subjected to jet milling to obtain a lithium oxide material.

[0052] Example 3

[0053] The lithium oxide material is prepared according to the following steps:

[0054] (1) 6000g of lithium carbonate, 927.37g of Ketjen black, and 632.56g of polyethylene glycol are weighed and added to a ball mill, anhydrous ethanol is added as a dispersant, and stirring is performed for 30min, and then the slurry is ground in a sand mill to obtain a material a with a grinding particle size D50 of 0.27um;

[0055] (2) The material a obtained in step (1) is subjected to spray drying treatment to obtain material b; the spray inlet temperature is 220°C, and the outlet temperature is 100°C;

[0056] (3) The material b obtained in step (2) is sintered under an inert atmosphere to obtain material c; the sintering temperature is 750°C, and the sintering time is 24h;

[0057] (4) The material c obtained in step (3) is subjected to jet milling to obtain a lithium oxide material.

[0058] Example 4

[0059] The lithium oxide material is prepared according to the following steps:

[0060] (1) 6000 g of lithium carbonate, 937.07 g of Super P and 231.79 g of glucose are weighed and added to a ball mill, anhydrous ethanol is added as a dispersant, and after stirring for 30 min, the slurry is ground in a sand mill to a grinding particle size D50 of 0.23 um to obtain material a;

[0061] (2) The material a obtained in step (1) is subjected to spray drying to obtain material b; the spray inlet temperature is 220°C, and the outlet temperature is 100°C;

[0062] (3) The material b obtained in step (2) is sintered under an inert atmosphere to obtain material c; the sintering temperature is 900°C, and the sintering time is 24 h;

[0063] (4) The material c obtained in step (3) is subjected to jet milling to obtain a lithium oxide material.

[0064] Figure 2 The lithium iron phosphate positive electrode material prepared in Example 4 has a charge-discharge performance curve in the voltage range of 2.0-4.5 V at a rate of 0.1 C, and the discharge specific capacity reaches 158 mAh / g.

[0065] Comparative Example 1

[0066] The lithium oxide material is prepared according to the following steps:

[0067] (1) 500 g of lithium carbonate is weighed and sintered under an inert atmosphere to obtain material c; the sintering temperature is 850°C, and the sintering time is 36 h;

[0068] (2) The material c obtained in step (3) is subjected to jet milling to obtain a lithium oxide material.

[0069] Comparative Example 2

[0070] The lithium oxide material is prepared according to the following steps:

[0071] 6000 g of lithium carbonate and 960.32 g of Super P are weighed and added to a ball mill, anhydrous ethanol is added as a dispersant, and after stirring for 30 min, the slurry is ground in a sand mill to a grinding particle size D50 of 0.33 um to obtain material a;

[0072] (2) The material a obtained in step (1) is subjected to spray drying treatment to obtain material b; the spray inlet temperature is 220°C, and the outlet temperature is 100°C;

[0073] (3) The material b obtained in step (2) is sintered under an inert atmosphere to obtain material c; the sintering temperature is 850°C, and the sintering time is 24 h;

[0074] (4) The material c obtained in step (3) is subjected to jet milling to obtain a lithium oxide material.

[0075] Comparative Example 3

[0076] The lithium oxide material is purchased.

[0077] The lithium oxide materials of Examples 1-4 and Comparative Examples 1-3 are subjected to carbon content detection, lithium content detection, and XRD detection, the XRD spectrum results are shown in Figure 2 The carbon content, lithium content, and related component results determined by the comparative standard card are shown in Table 1.

[0078] Table 1 Basic physicochemical indexes of lithium oxide materials

[0079] Carbon content (wt. %) Lithium content (wt. %) XRD crystalline form Example 1 0.1068 45.84 Lithium oxide Example 2 0.1462 45.34 Lithium oxide Example 3 0.3585 43.52 Lithium oxide, lithium carbonate Example 4 0.2682 44.89 Lithium oxide Comparative Example 1 13.3715 21.96 Lithium carbonate, lithium oxide Comparative Example 2 0.5222 43.52 Lithium oxide, lithium carbonate Comparative Example 3 0.1191 45.11 Lithium oxide

[0080] According to the above results, it can be seen that the lithium oxide materials prepared in Examples 1-4 have higher purity, close to the purchased lithium oxide material, and even better than the purchased lithium oxide material.

[0081] Since the process route of this scheme is similar to the existing lithium iron phosphate process, the corresponding required equipment is basically the same, the process control is more mature, and it can be used after simple modification based on the existing production line;

[0082] This scheme is based on the carbothermal reduction of lithium carbonate reaction. Lithium oxide is produced by the reaction of carbon generated by the decomposition of carbon source at high temperature and lithium carbonate. The raw materials required include lithium carbonate and carbon source;

[0083] This scheme is based on the carbothermal reduction of lithium carbonate reaction. Lithium oxide is produced by the reaction of carbon generated by the decomposition of carbon source at high temperature and lithium carbonate. The carbon source used is a composite carbon source, including inorganic carbon source and small-molecule organic carbon source. The advantage is that the inorganic carbon source can act as a reducing agent and participate in the high-temperature thermal reduction of lithium carbonate in large quantities. The small-molecule organic carbon source produces a large amount of gas after high-temperature decomposition, which can promote the full progress of the lithium carbonate reduction reaction.

[0084] The preparation method of the lithium oxide material provided by the embodiment of the present application is based on the carbothermal reduction of lithium carbonate reaction, a lithium source slurry is obtained by liquid phase grinding of a carbon source and lithium carbonate, and the lithium oxide is prepared after spray drying, calcination and post-treatment, the material has high purity and uniform particles. In addition, the process route adopted by the method has similarities with the existing lithium iron phosphate process route, the required equipment is basically the same, and the process equipment requirement is further reduced. The process flow of the preparation method is simple, the equipment requirement is low, and the method is suitable for large-scale industrial production.

[0085] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0086] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for producing a lithium oxide material, characterized by, The preparation method comprises: S10, mixing lithium carbonate, carbon source and dispersant in a certain proportion, stirring and dispersing, wet grinding to obtain an intermediate liquid; S20, spray drying the intermediate liquid to obtain an intermediate; S30, sintering and crushing the intermediate in a protective atmosphere to obtain the lithium oxide material; The carbon source comprises inorganic carbon source and organic carbon source; The inorganic carbon source comprises at least one of conductive carbon black, carbon nanotube, vapor grown carbon fiber, graphene and biomass carbon; the organic carbon source comprises at least one of glucose, sucrose, starch, fructose, maltose, cyclodextrin, citric acid, polyethylene glycol, polyvinyl alcohol and glycerol.

2. The method for producing a lithium oxide material according to claim 1, characterized by, The dispersant comprises one of deionized water and anhydrous ethanol.

3. The method of claim 1, wherein the lithium oxide material is prepared by the steps of: preparing a mixture of lithium hydroxide and water; and heating the mixture to a temperature of 200 °C to 400 °C. The wet grinding has a grinding granularity D50 of 0.1-1.0 microns.

4. The method of claim 1, wherein the lithium oxide material is prepared by the steps of: The spray drying process has a spray inlet temperature of 200-280 DEG C and an outlet temperature of 90-120 DEG C.

5. The method for preparing lithium oxide material according to claim 1, characterized in that, The protective atmosphere comprises one of rare gas atmosphere and vacuum atmosphere.

6. The method of claim 5, wherein the lithium oxide material is prepared by a process comprising: The rare gas atmosphere comprises argon.

7. The method of claim 6, wherein the lithium oxide material is prepared by a process comprising: The sintering process has a sintering temperature of 700-1200 DEG C and a sintering time of 6-48 hours.

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