Battery cathode material, preparation method thereof and application thereof
By preparing aluminum cobalt nickel trimetallic hydroxyl oxide as the cathode material for aqueous magnesium-ion batteries, the problem of low energy density was solved, and high energy density and capacity retention were improved, thus enhancing battery performance.
Patent Information
- Application Number
- CN202510109750.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2045-01-23
AI Technical Summary
The low energy density and capacity of aqueous magnesium-ion battery cathode materials limit their further development and application.
By using aluminum, cobalt, and nickel trimetallic hydroxyl oxides as the cathode material, and by controlling the molar ratio of aluminum, cobalt, and nickel, and preparing the battery cathode material through cyclic voltammetry, the energy density and capacity retention of the material are improved.
This study achieved high energy density and excellent capacity retention in aqueous magnesium-ion battery cathode materials, thereby improving the overall performance of the battery.
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Figure CN119943935B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of batteries, and particularly relates to a battery positive electrode material and a preparation method and application thereof. BACKGROUND
[0002] The rapid development of society has continuously increased the demand for energy, which has promoted the development of efficient energy storage technology. In recent years, aqueous magnesium ion batteries have attracted extensive attention due to their own advantages. Magnesium is inexpensive and has abundant reserves on earth, which can effectively reduce the cost. Compared with traditional organic electrolytes, aqueous electrolytes have the advantages of non-flammability, safety, non-toxicity and higher ionic conductivity, which avoids the safety problems that may be caused by organic electrolytes. Therefore, aqueous magnesium ion batteries are a kind of aqueous energy storage system with great application prospect.
[0003] However, the further development and application of aqueous magnesium ion batteries are limited by the bottleneck of positive electrode materials. First, most magnesium ion battery positive electrodes are matched with organic electrolytes, and there are few positive electrode materials matched with aqueous electrolytes, mainly manganese-based oxides, vanadium-based oxides and prussian blue analogues. Secondly, the discharge capacity and working voltage of the current aqueous magnesium ion battery positive electrode are at a low level, which greatly limits the energy density of the aqueous magnesium ion battery.
[0004] The information disclosed in this BACKGROUND section is only for the purpose of increasing the understanding of the background of the application and should not be regarded as an acknowledgment or any form of suggestion that this information forms prior art that is already known to a person of ordinary skill in the art. SUMMARY
[0005] The purpose of the present application is to provide a battery positive electrode material and a preparation method and application thereof, which has a high energy density and capacity retention rate and can solve the problem of low energy density of the current aqueous magnesium ion battery positive electrode.
[0006] In order to achieve the above-mentioned purpose, the technical scheme provided by an embodiment of the present application is as follows:
[0007] A battery positive electrode material is a hydroxyl oxide of aluminum-cobalt-nickel three metals, and in the hydroxyl oxide, the molar ratio of aluminum elements, cobalt elements and nickel elements in terms of atomic number is x:y:z, wherein the sum of x, y and z is 1, 0.05≤x≤0.15, and 0.25≤y≤0.35.
[0008] The technical scheme provided by another embodiment of the present application is as follows:
[0009] A preparation method of the battery positive electrode material of claim 1, comprising:
[0010] S1, dissolve aluminum salt, cobalt salt and nickel salt in deionized water to prepare a metal salt solution, then add an alkali solution, and react to generate a precipitate, wash and dry the precipitate to obtain a precursor powder;
[0011] S2, prepare a slurry from the precursor powder, coat the slurry on a substrate, and dry to obtain a precursor electrode sheet;
[0012] S3, oxidize the precursor electrode sheet in a three-electrode system by cyclic voltammetry to obtain a battery positive electrode material.
[0013] In one or more embodiments of the present application, in step S1, the total concentration of aluminum ions, cobalt ions and nickel ions in the metal salt solution is 0.2-0.5 mol / L.
[0014] In one or more embodiments of the present application, in step S1, the molar ratio of alkali to the sum of metal ions in the metal salt solution is (2-2.5):1.
[0015] In one or more embodiments of the present application, in step S2, the precursor powder, a conductive agent and a binder are dispersed in a solvent according to a mass ratio of (7-8):(1-2):1 to prepare a slurry.
[0016] In one or more embodiments of the present application, in step S3, the oxidation operation is: cycling 8-12 times at a scan rate of 15-25 mV / s at a voltage of-0.15-0.55 V.
[0017] In one or more embodiments of the present application, the aluminum salt is at least one of aluminum nitrate and aluminum sulfate.
[0018] In one or more embodiments of the present application, the cobalt salt is at least one of cobalt nitrate and cobalt sulfate.
[0019] In one or more embodiments of the present application, the nickel salt is at least one of nickel nitrate and nickel sulfate.
[0020] Another specific embodiment of the present application provides a technical solution as follows:
[0021] The above battery positive electrode material or the battery positive electrode material prepared by the above preparation method is applied in a water-based magnesium ion battery.
[0022] Compared with the prior art, the battery positive electrode material in the present application uses a high proportion of nickel element as the main active element in the charging and discharging process, simultaneously introduces an appropriate amount of cobalt element to improve the capacity retention rate of the positive electrode material, and introduces an appropriate amount of aluminum element to improve the energy density of the positive electrode material. The battery positive electrode material prepared can be used as an electrode of a water-based magnesium ion battery, has a high energy density, and effectively solves the current situation of low energy density of the positive electrode of the water-based magnesium ion battery. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 This is a comparison of the charge-discharge curves of aluminum cobalt nickel trimetallic hydroxyl oxide in Example 1 and nickel hydroxyl oxide in Comparative Example 1 as the positive electrode of an aqueous magnesium ion battery in a three-electrode system.
[0025] Figure 2 This invention compares the cycle capacity retention rates of aluminum-cobalt-nickel trimetallic hydroxyl oxide in Example 1 and nickel hydroxyl oxide in Comparative Example 1 as positive electrodes in an aqueous magnesium-ion battery in a three-electrode system.
[0026] Figure 3 The charge-discharge curves of aluminum cobalt nickel trimetallic hydroxyl oxide as the positive electrode of an aqueous magnesium ion battery in a three-electrode system are shown in Example 2 of this invention.
[0027] Figure 4 The charge-discharge curves of aluminum cobalt nickel trimetallic hydroxyl oxide as the positive electrode of an aqueous magnesium ion battery in a three-electrode system are shown in Example 3 of this invention.
[0028] Figure 5 The charge-discharge curves of aluminum cobalt nickel trimetallic hydroxyl oxide as the positive electrode of an aqueous magnesium ion battery in a three-electrode system are shown in Example 4 of this invention.
[0029] Figure 6 The charge-discharge curves of aluminum cobalt nickel trimetallic hydroxyl oxide as the positive electrode of an aqueous magnesium ion battery in the three-electrode system of Comparative Example 2 of this invention are shown.
[0030] Figure 7 The charge-discharge curves of aluminum cobalt nickel trimetallic hydroxyl oxide as the positive electrode of an aqueous magnesium-ion battery in a three-electrode system are shown in Comparative Example 3 of this invention. Detailed Implementation
[0031] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.
[0032] The embodiment of the present application provides a battery positive electrode material, which is a hydroxyl oxide of aluminum, cobalt and nickel, and the molar ratio of aluminum, cobalt and nickel is x:y:z, wherein the sum of x, y and z is 1, 0.05<=x<=0.15, and 0.25<=y<=0.35.
[0033] Specifically, the nickel element is the main active element in the charging and discharging process, and needs to maintain a high proportion as the core element among the three metal elements to ensure the positive electrode specific capacity. The introduction of the cobalt element can significantly improve the capacity retention rate of the positive electrode material, and needs to reach a certain proportion to have a more obvious capacity retention rate improvement effect, but too high will reduce the proportion of the nickel element, and then reduce the positive electrode specific capacity, therefore, the proportion of the cobalt element in the present application is controlled in the appropriate range, which can ensure the positive electrode specific capacity and the capacity retention rate at the same time. The introduction of the aluminum element can improve the discharge voltage of the positive electrode material, and then can improve the energy density of the positive electrode material, and the proportion of the aluminum element in the present application has reached the edge of the voltage window of the electrolyte, therefore, the aluminum element proportion defined in the present application can fully play the role of the aluminum element in the positive electrode material.
[0034] Further, the specific values of x, y and z can be selected within the range defined in the present application, for example, the specific value of x can be 0.05, 0.07, 0.09, 0.10, 0.012, 0.13 or 0.15, and the specific value of y can be 0.25, 0.28, 0.30, 0.32, 0.34 or 0.35.
[0035] The embodiment of the present application further provides a preparation method of the battery positive electrode material, which comprises steps 1-3.
[0036] Step 1, dissolving aluminum salt, cobalt salt and nickel salt in deionized water to prepare a metal salt solution, then adding an alkali solution to react to generate a precipitate, washing and drying the obtained precipitate to obtain a precursor powder.
[0037] Specifically, the aluminum salt is at least one of aluminum nitrate and aluminum sulfate, the cobalt salt is at least one of cobalt nitrate and cobalt sulfate, the nickel salt is at least one of nickel nitrate and nickel sulfate, the alkali is at least one of sodium hydroxide and potassium hydroxide, and the alkali solution is an aqueous solution of the alkali with a molar concentration of 2.5-3.5 M.
[0038] The total concentration of aluminum ions, cobalt ions and nickel ions in the metal salt solution is 0.2-0.5 mol / L, and the molar ratio of the alkali to the sum of metal ions in the metal salt solution is (2-2.5):1. By controlling the amount of raw materials, the aluminum salt, the cobalt salt and the nickel salt can be generated into a precipitate by a coprecipitation method.
[0039] The precipitate is washed with deionized water and anhydrous ethanol in sequence, and then dried in an oven at 50-80 DEG C for 8-16 hours. The unreacted salt and alkali on the surface of the precipitate can be removed by washing to ensure the purity of the product.
[0040] Step 2, the precursor powder is made into a slurry, the slurry is coated on a substrate, and the precursor electrode sheet is obtained after drying.
[0041] Specifically, the slurry is prepared by dispersing the precursor powder, the conductive agent and the binder in the solvent, and the mass ratio of the precursor powder, the conductive agent and the binder is (7-8):(1-2):1, and the ratio of the binder to the solvent is 10-20 mg / ml, that is, 1 ml of solvent is used for every 10-20 mg of binder. The conductive agent is selected as acetylene black, the binder is selected as polyvinylidene fluoride, and the solvent is selected as N-methyl pyrrolidone. The substrate is carbon cloth, and the thickness of the slurry coated on the carbon cloth substrate is 100-200 microns. After coating, the slurry is dried in an oven at 50-80 DEG C for 8-16 hours.
[0042] Step 3, the precursor electrode sheet is oxidized in a three-electrode system by cyclic voltammetry to obtain a battery positive electrode material.
[0043] Specifically, the precursor electrode sheet is used as the working electrode, the carbon electrode is used as the counter electrode, the silver / silver chloride is used as the reference electrode, the oxidation solution is a 1M concentration of potassium hydroxide solution, and the cyclic voltammetry is used to cycle 8-12 times at a scanning speed of 15-25 mV / s under a voltage of-0.15-0.55V.
[0044] Another specific embodiment of the present application provides the application of the above-mentioned battery positive electrode material or the battery positive electrode material prepared by the above-mentioned preparation method in a water-based magnesium ion battery.
[0045] Specifically, the battery positive electrode material in the present application has a high energy density when used as the positive electrode of the water-based magnesium ion battery.
[0046] The present application will be further described in detail below in combination with specific embodiments.
[0047] Example 1
[0048] The battery positive electrode material is prepared as follows:
[0049] (1) Preparation of precursor powder
[0050] 0.0015 mol of aluminum nitrate, 0.0045 mol of cobalt nitrate and 0.009 mol of nickel nitrate are added to 40 mL of deionized water, and after being fully dissolved by stirring, 10 mL of 3M concentration of potassium hydroxide solution is added dropwise, and a precipitate is generated by reaction. The lower layer precipitate in the solution is washed with deionized water and anhydrous ethanol in sequence, and then dried in an oven at 60 DEG C for 12 hours to obtain the precursor powder.
[0051] (2) Preparation of precursor slurry
[0052] The precursor powder, acetylene black and polyvinylidene fluoride were dispersed in N-methyl pyrrolidone at a mass ratio of 7:2:1, 1 ml of N-methyl pyrrolidone was used for every 10 mg of polyvinylidene fluoride, to prepare the precursor slurry.
[0053] (3) Preparation of precursor electrode sheet
[0054] The precursor slurry was uniformly coated on the carbon cloth substrate with a coating thickness of 200 μm, and then dried in an oven at 60°C to prepare the precursor electrode sheet.
[0055] (4) Oxidation of electrode sheet
[0056] The precursor electrode sheet was oxidized in a three-electrode system, the oxidation solution was 1M potassium hydroxide solution, the precursor electrode sheet was the working electrode, the carbon electrode was the counter electrode, and the silver / silver chloride was the reference electrode. The cyclic voltammetry was used to cycle 10 times in the voltage range of -0.15-0.55V at a scan rate of 20mV / s to prepare the aluminum-cobalt-nickel three-metal hydroxyl oxide, i.e. the battery positive electrode material.
[0057] Example 2
[0058] The battery positive electrode material was prepared as follows:
[0059] (1) Preparation of precursor powder
[0060] 0.0005 mol of aluminum nitrate, 0.0035 mol of cobalt nitrate and 0.006 mol of nickel nitrate were added to 27 mL of deionized water, and after stirring to dissolve completely, 7 mL of 3M potassium hydroxide solution was added dropwise, and a precipitate was formed. The lower precipitate in the solution was washed with deionized water and anhydrous ethanol, and then dried in an oven at 60°C for 12h to obtain the precursor powder.
[0061] (2) Preparation of precursor slurry
[0062] The precursor powder, acetylene black and polyvinylidene fluoride were dispersed in N-methyl pyrrolidone at a mass ratio of 7:2:1, 1 ml of N-methyl pyrrolidone was used for every 10 mg of polyvinylidene fluoride, to prepare the precursor slurry.
[0063] (3) Preparation of precursor electrode sheet
[0064] The precursor slurry was uniformly coated on the carbon cloth substrate with a coating thickness of 200 μm, and then dried in an oven at 60°C to prepare the precursor electrode sheet.
[0065] (4) Oxidation of electrode sheet
[0066] The precursor electrode sheet is oxidized in a three-electrode system, the oxidation solution is a 1M potassium hydroxide solution, the precursor electrode sheet is the working electrode, the carbon electrode is the counter electrode, and the silver / silver chloride is the reference electrode. The aluminum-cobalt-nickel trimetallic oxyhydroxide, i.e. the battery positive electrode material, is prepared by using cyclic voltammetry in a voltage range of -0.15-0.55V at a scan rate of 20mV / s for 10 cycles.
[0067] Example 3
[0068] The battery positive electrode material is prepared as follows:
[0069] (1) Precursor powder preparation
[0070] 0.0015mol aluminum nitrate, 0.0025mol cobalt nitrate, and 0.006mol nickel nitrate are added to 27mL deionized water, and after being fully stirred and dissolved, 7mL of a 3M potassium hydroxide solution is added dropwise, and a precipitate is generated by reaction. The lower layer precipitate in the solution is washed with deionized water and anhydrous ethanol, and then dried in a 60°C oven for 12h to obtain the precursor powder.
[0071] (2) Precursor slurry preparation
[0072] The precursor powder, acetylene black, and polyvinylidene fluoride are dispersed in N-methyl pyrrolidone at a mass ratio of 7:2:1, and 1ml of N-methyl pyrrolidone is used for every 10mg of polyvinylidene fluoride to prepare the precursor slurry.
[0073] (3) Precursor electrode sheet preparation
[0074] The precursor slurry is uniformly coated on a carbon cloth substrate with a coating thickness of 200μm, and then dried in a 60°C oven to prepare the precursor electrode sheet.
[0075] (4) Electrode sheet oxidation
[0076] The precursor electrode sheet is oxidized in a three-electrode system, the oxidation solution is a 1M potassium hydroxide solution, the precursor electrode sheet is the working electrode, the carbon electrode is the counter electrode, and the silver / silver chloride is the reference electrode. The aluminum-cobalt-nickel trimetallic oxyhydroxide, i.e. the battery positive electrode material, is prepared by using cyclic voltammetry in a voltage range of -0.15-0.55V at a scan rate of 20mV / s for 10 cycles.
[0077] Example 4
[0078] The battery positive electrode material is prepared as follows:
[0079] (1) Precursor powder preparation
[0080] 0.0015 mol of aluminum nitrate, 0.0035 mol of cobalt nitrate and 0.005 mol of nickel nitrate were added into 27 mL of deionized water, and after being fully dissolved by stirring, 7 mL of 3 M potassium hydroxide solution was added dropwise, and a precipitate was generated by reaction. The lower precipitate in the solution was taken, and the precipitate was washed with deionized water and anhydrous ethanol in sequence, and then dried in a 60°C oven for 12 h to obtain a precursor powder.
[0081] (2) Preparation of precursor slurry
[0082] The precursor powder, acetylene black and polyvinylidene fluoride were dispersed in N-methyl pyrrolidone at a mass ratio of 7:2:1, 1 mL of N-methyl pyrrolidone was used for every 10 mg of polyvinylidene fluoride, to prepare a precursor slurry.
[0083] (3) Preparation of precursor electrode sheet
[0084] The precursor slurry was uniformly coated on a carbon cloth substrate with a coating thickness of 200 μm, and then dried in a 60°C oven to prepare a precursor electrode sheet.
[0085] (4) Oxidation of electrode sheet
[0086] The precursor electrode sheet was oxidized in a three-electrode system, the oxidation solution was 1 M potassium hydroxide solution, the precursor electrode sheet was the working electrode, the carbon electrode was the counter electrode, and the silver / silver chloride was the reference electrode. The cyclic voltammetry was used to cycle 10 times in the voltage range of -0.15-0.55 V at a scan rate of 20 mV / s to prepare aluminum-cobalt-nickel tri-metallic oxyhydroxide, i.e. a battery positive electrode material.
[0087] Comparative Example 1
[0088] The battery positive electrode material was prepared as follows:
[0089] (1) Preparation of precursor powder
[0090] 0.015 mol of nickel nitrate was added into 40 mL of deionized water, and after being fully dissolved by stirring, 10 mL of 3 M potassium hydroxide solution was added dropwise, and a precipitate was generated by reaction. The lower precipitate in the solution was taken, and the precipitate was washed with deionized water and anhydrous ethanol in sequence, and then dried in a 60°C oven for 12 h to obtain a precursor powder.
[0091] (2) Preparation of precursor slurry
[0092] The precursor powder, acetylene black and polyvinylidene fluoride were dispersed in N-methyl pyrrolidone at a mass ratio of 7:2:1, 1 mL of N-methyl pyrrolidone was used for every 10 mg of polyvinylidene fluoride, to prepare a precursor slurry.
[0093] (3) Preparation of precursor electrode sheet
[0094] The precursor slurry was uniformly coated on the carbon cloth substrate with a coating thickness of 200 pm, and then dried in an oven at 60°C to prepare the precursor electrode sheet.
[0095] (4) Electrode sheet oxidation
[0096] The precursor electrode sheet was oxidized in a three-electrode system, the oxidation solution was a 1M potassium hydroxide solution, the precursor electrode sheet was the working electrode, the carbon electrode was the counter electrode, and the silver / silver chloride was the reference electrode. The nickel hydroxide, i.e. the battery positive electrode material, was prepared by using cyclic voltammetry in the voltage range of -0.15-0.55V with a scan rate of 20mV / s for 10 cycles.
[0097] Comparative Example 2
[0098] The battery positive electrode material was prepared as follows:
[0099] (1) Precursor powder preparation
[0100] 0.0015 mol of aluminum nitrate, 0.0075 mol of cobalt nitrate, and 0.006 mol of nickel nitrate were added to 40 mL of deionized water, and after stirring to fully dissolve, 10 mL of 3M potassium hydroxide solution was added dropwise, and a precipitate was formed by reaction. The lower layer precipitate in the solution was washed with deionized water and anhydrous ethanol, and then dried in a 60°C oven for 12h to obtain the precursor powder.
[0101] (2) Precursor slurry preparation
[0102] The precursor powder, acetylene black, and polyvinylidene fluoride were dispersed in N-methyl pyrrolidone in a mass ratio of 7:2:1, and 1ml of N-methyl pyrrolidone was used for every 10mg of polyvinylidene fluoride to prepare the precursor slurry.
[0103] (3) Precursor electrode sheet preparation
[0104] The precursor slurry was uniformly coated on the carbon cloth substrate with a coating thickness of 200 pm, and then dried in an oven at 60°C to prepare the precursor electrode sheet.
[0105] (4) Electrode sheet oxidation
[0106] The precursor electrode sheet was oxidized in a three-electrode system, the oxidation solution was a 1M potassium hydroxide solution, the precursor electrode sheet was the working electrode, the carbon electrode was the counter electrode, and the silver / silver chloride was the reference electrode. The aluminum-cobalt-nickel tri-metallic hydroxide, i.e. the battery positive electrode material, was prepared by using cyclic voltammetry in the voltage range of -0.15-0.55V with a scan rate of 20mV / s for 10 cycles.
[0107] Comparative Example 3
[0108] A battery positive electrode material is prepared as follows:
[0109] (1) Preparation of precursor powder
[0110] 0.0045 mol of aluminum nitrate, 0.0045 mol of cobalt nitrate and 0.006 mol of nickel nitrate were added into 40 mL of deionized water, and after being fully stirred and dissolved, 10 mL of a 3M potassium hydroxide solution was added dropwise, and a precipitate was generated by reaction. The lower layer precipitate in the solution was washed with deionized water and anhydrous ethanol, and then dried in a 60°C oven for 12 hours to obtain the precursor powder.
[0111] (2) Preparation of precursor slurry
[0112] The precursor powder, acetylene black and polyvinylidene fluoride were dispersed in N-methyl pyrrolidone at a mass ratio of 7:2:1, 1 mL of N-methyl pyrrolidone was used for every 10 mg of polyvinylidene fluoride, to prepare the precursor slurry.
[0113] (3) Preparation of precursor electrode sheet
[0114] The precursor slurry was uniformly coated on a carbon cloth substrate with a coating thickness of 200 μm, and then dried in a 60°C oven to prepare the precursor electrode sheet.
[0115] (4) Oxidation of the electrode sheet
[0116] The precursor electrode sheet was oxidized in a three-electrode system, the oxidation solution was a 1M potassium hydroxide solution, the precursor electrode sheet was the working electrode, the carbon electrode was the counter electrode, and the silver / silver chloride electrode was the reference electrode. The cyclic voltammetry method was used to cycle 10 times in the voltage range of -0.15-0.55V at a scan rate of 20 mV / s to prepare the aluminum-cobalt-nickel three-metal hydroxyl oxide, i.e. the battery positive electrode material.
[0117] The battery positive electrode material in the examples and comparative examples was taken as the working electrode, a carbon electrode was used as the counter electrode, a silver / silver chloride electrode was used as the reference electrode, and the electrolyte solution was a magnesium salt aqueous solution, the concentration of magnesium ions was 1 mol / L, wherein the magnesium salt was at least one of magnesium sulfate and magnesium chloride, and the magnesium chloride aqueous solution was selected in the present application. The battery positive electrode material was tested under the test conditions of a current density of 500 mA / g, and the results are shown in Table 1. Figures 1-7
[0118] Referring to Table 1, Figures 1-2 Compared with the nickel hydroxyl oxide in Comparative Example 1, the aluminum-cobalt-nickel three-metal hydroxyl oxide in Example 1 showed higher discharge voltage and discharge specific capacity when used as a battery positive electrode material, the energy density was higher than that of Comparative Example 1, and the capacity attenuation of the aluminum-cobalt-nickel three-metal hydroxyl oxide was less during the cycle process, and the performance was better. Figures 3-5 The aluminum cobalt nickel trimetallic oxyhydroxide in Examples 2-4 also exhibits a high discharge voltage and discharge specific capacity, indicating that the aluminum cobalt nickel trimetallic oxyhydroxide in the present application has a high energy density.
[0119] The amount of cobalt element in the aluminum cobalt nickel trimetallic oxyhydroxide in Comparative Example 2 exceeds the range defined in the present application, and the amount of nickel element in the aluminum cobalt nickel trimetallic oxyhydroxide in Comparative Example 3 exceeds the range defined in the present application. Figures 6-7 As can be seen from the above, when an excess amount of cobalt element or nickel element is used, the content of nickel element is reduced, the discharge specific capacity of the positive electrode material is reduced, and the energy density is reduced, thereby verifying that the aluminum cobalt nickel trimetallic oxyhydroxide prepared in the proportions disclosed in the present application can ensure that it has a better use performance.
[0120] It will be obvious to a person skilled in the art that the application is not limited to the details of the above-described exemplary embodiments, and that the application can be implemented in other specific forms without departing from the spirit or essential characteristics of the application. Therefore, the embodiments should be considered as exemplary and non-limiting, and the scope of the application is defined by the appended claims rather than the above description, and all changes falling within the meaning and range of the equivalent elements of the claims are intended to be encompassed by the application. Any reference signs in the claims should not be considered as limiting the claims to which they relate.
[0121] Furthermore, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the present specification is described in this way only for the sake of clarity, and a person skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by a person skilled in the art.
Claims
1. An application of a battery positive electrode material in a water-based magnesium ion battery, characterized in that, The battery positive electrode material is an aluminum-cobalt-nickel three-metal hydroxyl oxide, in which the molar ratio of aluminum, cobalt and nickel in terms of atomic number is x:y:z, wherein the sum of x, y and z is 1, 0.05≤x≤0.15, and 0.25≤y≤0.
35.
2. Use according to claim 1, characterized in that, The preparation method of the battery positive electrode material comprises: S1, dissolving aluminum salt, cobalt salt and nickel salt in deionized water to prepare a metal salt solution, then adding an alkali solution to generate a precipitate, washing and drying the obtained precipitate to obtain a precursor powder; S2, preparing a slurry from the precursor powder, coating the slurry on a substrate, and drying to obtain a precursor electrode sheet; S3, oxidizing the precursor electrode sheet in a three-electrode system by cyclic voltammetry to obtain the battery positive electrode material.
3. Use according to claim 2, characterized in that, In step S1, the total concentration of aluminum ions, cobalt ions and nickel ions in the metal salt solution is 0.2-0.5 mol / L.
4. Use according to claim 2, characterized in that, In step S1, the molar ratio of the sum of alkali and metal ions in the metal salt solution is (2-2.5):
1.
5. Use according to claim 2, characterized in that, In step S2, the precursor powder, conductive agent and binder are dispersed in a solvent according to a mass ratio of (7-8):(1-2):1 to prepare the slurry.
6. Use according to claim 2, characterized in that, In step S3, the oxidation operation is: cycling 8-12 times at a scan rate of 15-25 mV / s under a voltage of-0.15-0.55 V.
7. Use according to claim 2, characterized in that, The aluminum salt is at least one of aluminum nitrate and aluminum sulfate.
8. Use according to claim 2, characterized in that, The cobalt salt is at least one of cobalt nitrate and cobalt sulfate.
9. Use according to claim 2, characterized in that, The nickel salt is at least one of nickel nitrate and nickel sulfate.