Sodium battery precursor, preparation method and application thereof

Abstract

This invention provides a sodium-ionized precursor, its preparation method, and its application. The preparation method includes the following steps: (1) mixing a transition metal source with a solvent and placing it in a reaction vessel, adding a complexing agent, sealing the opening of the reaction vessel with a thin film, and punching holes in the thin film; (2) placing the reaction vessel and ammonium bicarbonate solid in a vacuum drying oven to carry out a gas diffusion reaction to obtain the sodium-ionized precursor. This invention uses a novel gas diffusion method to replace the traditional co-precipitation method to prepare sodium-ionized carbonate precursors. The precursor particles prepared have good sphericity and dispersibility, and the raw materials and operation are simple, the energy consumption is low, and it is easy to promote and realize industrial production.

Description

Technical Field

[0001] This invention belongs to the field of sodium-ion battery technology, and relates to a sodium battery precursor, its preparation method and application. Background Technology

[0002] Compared to lithium-ion batteries, sodium-ion batteries offer significant cost advantages and considerable electrochemical performance. In recent years, the industrialization of sodium-ion batteries has progressed steadily, and they are expected to effectively complement lithium-ion batteries in areas such as energy storage and power batteries. The cathode material is a key material in sodium-ion batteries, largely determining the battery's performance and cost.

[0003] Currently, sodium-ion battery cathode materials mainly include layered transition metal oxides, polyanionic compounds, and Prussian blue compounds. Among them, layered oxides have high specific capacity, simple preparation methods, and high compatibility with the process equipment for ternary cathode materials in lithium-ion batteries, making them the fastest-growing technology route for industrialization. Common methods for preparing layered oxide cathode materials for sodium-ion batteries include co-precipitation, high-temperature solid-state methods, and sol-gel methods. In industrial production, the mainstream method is to first obtain hydroxide or carbonate precursors through co-precipitation, then mix them with a lithium source, and finally obtain the final product through a high-temperature solid-state reaction. This method can effectively achieve uniform mixing of elements at the atomic and molecular level in the product, and can also precisely control the particle size and morphology as needed to obtain cathode materials with uniform particle size, good sphericity, and high tap density, and is convenient for large-scale industrial production.

[0004] CN109830679A discloses a cathode material precursor and its preparation method. The preparation method involves adding a mixed solution containing an iron source, a manganese source, a nickel source, and a doping component (one or a combination of two of aluminum, copper, and cobalt) dropwise to a mixed solution of sodium hydroxide and ammonia, and then heating the solution to obtain the cathode material precursor.

[0005] CN115872461A discloses a method for preparing a nickel-iron-manganese carbonate spherical precursor for sodium-ion battery cathode materials. The method employs carbonate co-precipitation technology, in which a nickel-iron-manganese salt solution, a sodium carbonate solution, and ammonia water are added dropwise to a prepared base solution via a peristaltic pump to carry out a co-precipitation reaction to obtain the nickel-iron-manganese carbonate precursor.

[0006] The precursor particles obtained by the method described above have problems with poor dispersibility and sphericity, which seriously hinders industrial production and application. Summary of the Invention

[0007] The purpose of this invention is to provide a sodium-ionized precursor, its preparation method, and its application. This invention uses a novel gas diffusion method to replace the traditional co-precipitation method to prepare sodium-ionized carbonate precursors. The precursor particles prepared have good sphericity and dispersibility, and the raw materials and operation are simple, the energy consumption is low, and it is easy to promote and realize industrial production.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for preparing a sodium-ion precursor, the method comprising the following steps:

[0010] (1) Mix the transition metal source with the solvent and place it in a reaction vessel. Add a complexing agent, seal the opening of the reaction vessel with a thin film, and poke holes in the thin film.

[0011] (2) The reaction vessel and ammonium bicarbonate solid were placed in a vacuum drying oven to carry out a gas diffusion reaction to obtain the sodium-ion precursor.

[0012] This invention drives the precipitation reaction through gas diffusion, making the reaction more uniform and controllable. The prepared precursor particles have a regular spherical morphology, good dispersibility and uniformity. The method uses simple raw materials and production equipment, is highly operable, has low energy consumption, is green and environmentally friendly, and is easy to mass-produce.

[0013] Preferably, the transition metal source in step (1) includes any two or at least three of the following: nickel source, copper source, iron source, or manganese source.

[0014] Preferably, the nickel source includes any one or a combination of at least two of nickel chloride, nickel nitrate, or nickel sulfate.

[0015] Preferably, the copper source includes any one or a combination of at least two of copper chloride, copper nitrate, or copper sulfate.

[0016] Preferably, the iron source includes any one or a combination of at least two of ferrous chloride, ferrous nitrate, or ferrous sulfate.

[0017] Preferably, the manganese source includes any one or a combination of at least two of manganese chloride, manganese nitrate, or manganese sulfate.

[0018] Preferably, the solvent includes anhydrous ethanol.

[0019] Preferably, the total concentration of the metal salt in the solution obtained after mixing is 1 to 100 g / L, for example: 1 g / L, 5 g / L, 10 g / L, 50 g / L or 100 g / L, etc.

[0020] Preferably, the complexing agent in step (1) includes any one or a combination of at least two of ammonia, oxalic acid, or lactic acid.

[0021] Preferably, the concentration of the complexing agent in the reaction solution is 0.1 to 0.5 mol / L, for example: 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L or 0.5 mol / L, etc.

[0022] Preferably, the film in step (1) comprises aluminum foil.

[0023] Preferably, the mass ratio of the ammonium bicarbonate solid in step (2) to the volume ratio of the reaction solution in the reaction vessel is (10-1000) g:1L, for example: 10g:1L, 20g:1L, 50g:1L, 200g:1L or 1000g:1L, etc.

[0024] Preferably, the temperature of the gas diffusion reaction in step (2) is 25 to 45°C, for example: 25°C, 30°C, 35°C, 40°C or 45°C.

[0025] Preferably, the gas diffusion reaction takes 1 to 5 days, for example: 1 day, 2 days, 3 days, 4 days or 5 days.

[0026] Preferably, the material obtained after the gas diffusion reaction in step (2) is washed and dried.

[0027] In a second aspect, the present invention provides a sodium-ion battery precursor, which is prepared by the method described in the first aspect, and the sodium-ion battery precursor has the chemical formula Ni. a Cu b Fe c Mn 1-a-b-c CO3, where 0 ≤ a < 0.4, for example: 0, 0.1, 0.2 or 0.3, etc.; 0 < b ≤ 0.3, for example: 0.05, 0.1, 0.2 or 0.3, etc.; 0 < c ≤ 0.4, for example: 0.05, 0.1, 0.2, 0.3 or 0.4, etc.

[0028] The sodium-ion battery precursor of this invention has a low nickel content and does not contain rare and precious metals such as cobalt, which reduces the production cost of cathode materials and has broad application prospects.

[0029] Thirdly, the present invention provides a sodium-ion battery cathode material, which is prepared by sintering a sodium-ion battery precursor and a sodium source as described in the second aspect.

[0030] Fourthly, the present invention provides a sodium-ion battery comprising the sodium-ion cathode material as described in the third aspect.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) This invention uses a novel gas diffusion method to replace the traditional co-precipitation method to prepare sodium-ion battery cathode material precursors. The precipitation reaction is driven by gas diffusion, making the reaction more uniform and controllable. The prepared precursor particles have a regular spherical morphology and good dispersibility and uniformity.

[0033] (2) The method described in this invention can produce a precursor with a Span of less than 0.976, and the specific surface area of ​​the copper-iron-manganese-sodium ionized precursor can reach 78 m². 2 / g or more, the specific surface area of ​​the nickel-iron-manganese-sodium electrolytic precursor can reach 15m². 2 / g or more, the specific surface area of ​​the nickel-copper-iron-manganese-sodium electrolytic precursor can reach 65m². 2 The tap density (TD) of the precursor can reach 1.06 g / cm³. 3 above. Attached Figure Description

[0034] Figure 1 This is a SEM image of the sodium-ion precursor described in Example 1. Detailed Implementation

[0035] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0036] Example 1

[0037] This embodiment provides a sodium-electric precursor, and the preparation method of the sodium-electric precursor is as follows:

[0038] (1) Weigh out copper chloride, ferrous chloride and manganese chloride according to the molar ratio Cu:Fe:Mn=1:2:2 and dissolve them in 100mL of anhydrous ethanol to prepare a 2g / L mixed solution. Add 3mL of 25% ammonia water, stir well, seal the mouth of the beaker with aluminum foil, and then poke 10 small holes in the aluminum foil.

[0039] (2) Weigh 10g of ammonium bicarbonate solid and place it in an open glass bottle. Then, place the mixed solution and ammonium bicarbonate solid from step (1) together in a vacuum drying oven for gas diffusion reaction, setting the reaction temperature to 30℃. After reacting for 50h, remove the beaker, centrifuge, wash, and dry the material to obtain the cathode material precursor Cu. 0.2 Fe 0.4 Mn 0.4 CO3. The SEM image of the precursor is shown below. Figure 1 As shown. By Figure 1 As can be seen, the present invention drives the precipitation reaction by gas diffusion, making the reaction more uniform and controllable, and the prepared precursor particles have a regular spherical morphology.

[0040] Example 2

[0041] This embodiment provides a sodium-electric precursor, and the preparation method of the sodium-electric precursor is as follows:

[0042] (1) Weigh out nickel chloride, ferrous chloride and manganese chloride according to the molar ratio Ni:Fe:Mn = 1:1:1 and dissolve them in 100mL of anhydrous ethanol to prepare a 4g / L mixed solution. Add 4mL of 25% ammonia water, stir evenly, seal the mouth of the beaker with aluminum foil, and then poke 10 small holes in the aluminum foil.

[0043] (2) Weigh 5g of ammonium bicarbonate solid and place it in an open glass bottle. Then, place the mixed solution and ammonium bicarbonate solid from step (1) together in a vacuum drying oven for gas diffusion reaction, setting the reaction temperature to 35℃. After reacting for 60h, remove the beaker, centrifuge, wash, and dry the material to obtain the cathode material precursor Ni. 1 / 3 Fe 1 / 3 Mn 1 / 3 CO3.

[0044] Example 3

[0045] This embodiment provides a sodium-electric precursor, and the preparation method of the sodium-electric precursor is as follows:

[0046] (1) Weigh out nickel chloride, copper chloride, ferrous chloride and manganese chloride according to the molar ratio Ni:Cu:Fe:Mn=3:2:2:3 and dissolve them in 100mL of anhydrous ethanol to prepare a 3g / L mixed solution. Add 5mL of 25% ammonia water, stir evenly, seal the mouth of the beaker with aluminum foil, and then poke 13 small holes in the aluminum foil.

[0047] (2) Weigh 10g of ammonium bicarbonate solid and place it in an open glass bottle. Then, place the mixed solution and ammonium bicarbonate solid from step (1) together in a vacuum drying oven for gas diffusion reaction, setting the reaction temperature to 40℃. After reacting for 48h, remove the beaker, centrifuge, wash, and dry the material to obtain the cathode material precursor Ni. 0.3 Cu 0.2 Fe 0.2 Mn 0.3 CO3.

[0048] Example 4

[0049] This embodiment provides a sodium-electric precursor, and the preparation method of the sodium-electric precursor is as follows:

[0050] (1) Weigh out copper chloride, ferrous chloride and manganese chloride according to the molar ratio Cu:Fe:Mn=1:2:2 and dissolve them in 100mL of anhydrous ethanol to prepare a 2g / L mixed solution. Add 3mL of 25% ammonia water, stir well, seal the mouth of the beaker with aluminum foil, and then poke 10 small holes in the aluminum foil.

[0051] (2) Weigh 10g of ammonium bicarbonate solid and place it in an open glass bottle. Then, place the mixed solution and ammonium bicarbonate solid from step (1) together in a vacuum drying oven for gas diffusion reaction, setting the reaction temperature to 25℃. After reacting for 50h, remove the beaker, centrifuge, wash, and dry the material to obtain the cathode material precursor Cu. 0.2 Fe 0.4 Mn 0.4 CO3.

[0052] Example 5

[0053] This embodiment provides a sodium-electric precursor, and the preparation method of the sodium-electric precursor is as follows:

[0054] (1) Weigh out copper chloride, ferrous chloride and manganese chloride according to the molar ratio Cu:Fe:Mn=1:2:2 and dissolve them in 100mL of anhydrous ethanol to prepare a 2g / L mixed solution. Add 3mL of 25% ammonia water, stir well, seal the mouth of the beaker with aluminum foil, and then poke 10 small holes in the aluminum foil.

[0055] (2) Weigh 10g of ammonium bicarbonate solid and place it in an open glass bottle. Then, place the mixed solution and ammonium bicarbonate solid from step (1) together in a vacuum drying oven for gas diffusion reaction, setting the reaction temperature to 45℃. After reacting for 50h, remove the beaker, centrifuge, wash, and dry the material to obtain the cathode material precursor Cu. 0.2 Fe 0.4 Mn 0.4 CO3.

[0056] Comparative Example 1

[0057] In this comparative example, the sodium-ion precursor Ni was prepared using a conventional co-precipitation method. 1 / 3 Fe 1 / 3 Mn 1 / 3 (OH)2, for specific methods, please refer to CN109830679A.

[0058] Performance testing:

[0059] The precursor materials prepared in Examples 1-5 and Comparative Example 1 were subjected to physical property testing. The median diameter of the laser-cut particle size (D) was measured. 50The span was measured using the Malvern 2000 laser diffraction method; the specific surface area was determined using the gas adsorption BET method; and the tap density (TD) was measured using a tap density meter, obtained by dividing the mass of the precursor material by its volume after vibration. The test results are shown in Table 1.

[0060] Table 1

[0061]

[0062] As can be seen from Table 1, the Span of the precursor prepared by the method of the present invention can reach below 0.976, and the specific surface area of ​​the copper-iron-manganese-sodium electrolytic precursor can reach 78 m². 2 / g or more, the specific surface area of ​​the nickel-iron-manganese-sodium electrolytic precursor can reach 15m². 2 / g or more, the specific surface area of ​​the nickel-copper-iron-manganese-sodium electrolytic precursor can reach 65m². 2 The yield is above 1.06 g / cm³, while the tap density (TD) of the precursor can reach 1.06 g / cm³. 3 In summary, this invention can produce precursors with large specific surface areas and high tap density for different metal elements, which is beneficial for sintering to produce high-performance cathode materials.

[0063] A comparison of Examples 1 and 4-5 shows that the temperature of the gas diffusion reaction affects the performance of the sodium-ion precursor during the preparation process of the sodium-ion precursor described in this invention. Controlling the temperature of the gas diffusion reaction between 25 and 45°C results in a better performance of the sodium-ion precursor. If the temperature of the gas diffusion reaction is too low, the precursor growth rate is slow and the production efficiency is low. If the temperature of the gas diffusion reaction is too high, the reaction rate is too fast, the precursor growth is difficult to control, the particle size uniformity is poor, and the solvent evaporates quickly.

[0064] As can be seen from the comparison between Example 1 and Comparative Example 1, the precipitation coefficients of commonly used nickel, iron, manganese and copper ions vary greatly. The conventional co-precipitation method for preparing precursors is prone to problems such as elemental segregation, uneven precipitation, and poor sphericity, uniformity and dispersibility. In addition, it often requires the use of complex complexing agent systems and preparation processes. The present invention uses a novel gas diffusion method to replace the traditional co-precipitation method to prepare sodium-ion battery cathode material precursors. The precipitation reaction is driven by gas diffusion, making the reaction more uniform and controllable. The prepared precursor particles have a regular spherical morphology and good dispersibility and uniformity.

[0065] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a sodium-ionized precursor, characterized in that, The preparation method includes the following steps: (1) Mix the transition metal source with the solvent and place it in the reaction vessel. Add the complexing agent, seal the opening of the reaction vessel with a thin film, and poke holes in the thin film. The transition metal source is a combination of at least three of the following: nickel source, copper source, iron source, or manganese source. The solvent is anhydrous ethanol; The total concentration of metal salts in the solution obtained after mixing is 1~10 g / L; The complexing agent in step (1) is ammonia. The concentration of the complexing agent in the reaction solution is 0.1~0.5 mol / L; (2) The reaction vessel and ammonium bicarbonate solid were placed in a vacuum drying oven to carry out a gas diffusion reaction to obtain the sodium-ion precursor; The mass ratio of the ammonium bicarbonate solid to the volume ratio of the reaction solution in the reaction vessel is (10~200) g: 1 L; The temperature of the gas diffusion reaction in step (2) is 25~45℃; The sodium electro-precurser has a chemical formula of Ni a Cu b Fe c Mn 1-a-b-c CO3, wherein 0≤a<0.4, 0 2. The preparation method according to claim 1, characterized in that, The nickel source includes any one or a combination of at least two of nickel chloride, nickel nitrate, or nickel sulfate.

3. The preparation method according to claim 1, characterized in that, The copper source includes any one or a combination of at least two of copper chloride, copper nitrate, or copper sulfate.

4. The preparation method according to claim 1, characterized in that, The iron source includes any one or a combination of at least two of ferrous chloride, ferrous nitrate, or ferrous sulfate.

5. The preparation method according to claim 1, characterized in that, The manganese source includes any one or a combination of at least two of manganese chloride, manganese nitrate, or manganese sulfate.

6. The preparation method according to claim 1, characterized in that, The film mentioned in step (1) is aluminum foil.

7. The preparation method according to claim 1, characterized in that, The gas diffusion reaction takes 1 to 5 days.

8. The preparation method according to claim 1, characterized in that, After the gas diffusion reaction in step (2), the obtained material is washed and dried.

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