High-entropy tungstate material for negative electrode of lithium ion battery, preparation method of high-entropy tungstate material, negative electrode plate and battery
By preparing a lithium-ion battery anode material with a uniform high-entropy tungstate nanosphere structure, the volume expansion problem of conversion materials was solved, achieving high capacity, excellent rate performance and long cycle stability, while simplifying the preparation process and reducing costs.
Patent Information
- Application Number
- CN202510953922.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-11
- Publication Date
- 2025-10-17
AI Technical Summary
The conversion materials of existing lithium-ion battery negative electrode materials seriously affect the long-cycle stability due to volume expansion. Traditional improvement methods are complex and not suitable for large-scale synthesis.
High-entropy tungstate materials with uniform and fine particle size are used to prepare nanosphere structures through hydrothermal reaction, simplifying the synthesis process and reducing costs.
It improves the specific capacity and rate performance of lithium-ion battery anodes, enhances cycle stability, simplifies the preparation process, and reduces costs.
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Figure CN120809816A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of lithium ion battery negative electrode materials, in particular to a high-entropy tungstate material for lithium ion battery negative electrodes, a preparation method thereof, a negative electrode sheet and a battery. BACKGROUND
[0002] Lithium ion batteries have been widely studied due to their high energy density, and have been commercialized on a large scale. The negative electrode material is an important component of lithium ion batteries. According to the type of redox reaction, it can be divided into intercalation type materials, conversion type materials and alloy type materials. Conversion type materials have attracted widespread attention due to their higher capacity than intercalation type materials and smaller volume expansion than alloy type materials. However, the volume expansion still seriously affects the long cycle stability. Traditional improvement measures generally modify the structure to improve the cycle stability, but such methods are not suitable for large-scale synthesis due to the complexity of the synthesis method. SUMMARY
[0003] Therefore, the present application provides a high-entropy tungstate material for lithium ion battery negative electrodes, a preparation method thereof, a negative electrode sheet and a battery. The high-entropy tungstate material for lithium ion battery negative electrodes has uniform and fine particle size, with a size of about 100-200 nm. This can effectively accelerate the transmission of ions and electrons, so that the material has high specific capacity, excellent rate performance and long cycle stability when used as a lithium ion battery negative electrode. In addition, the preparation method is simple and can be scaled up for production. The operation steps are controllable, which can effectively overcome the defects of the prior art.
[0004] The first aspect of the present application provides a high-entropy tungstate material for lithium ion battery negative electrodes. The chemical formula of the high-entropy tungstate material for lithium ion battery negative electrodes is (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )WO4.
[0005] The second aspect of the present application also provides a preparation method of the above-mentioned high-entropy tungstate material for lithium ion battery negative electrodes, comprising the following steps:
[0006] S1, dissolving a magnesium source, a cobalt source, a nickel source, a copper source and a zinc source in deionized water to obtain solution A; dissolving a sodium source in deionized water to obtain solution B; stirring the solution A and the solution B for a period of time;
[0007] S2, adding the stirred solution A to the solution B to obtain solution C, and ultrasonically treating the solution C for a period of time;
[0008] S3, the solution C after ultrasonic is carried out hydrothermal reaction, the precipitate obtained after reaction is recorded as precursor D; the precursor D is taken out after natural cooling to room temperature, centrifugal, washing, drying to obtain precursor E; the precursor E is carried out calcination treatment, and the high-entropy tungstate material for lithium ion battery negative electrode is obtained.
[0009] Preferably, in step S3, the hydrothermal reaction temperature is 180℃, and the hydrothermal reaction time is 10h.
[0010] Preferably, in step S3, the centrifugal speed is 4000r / min, and the centrifugal time is 2min; the washing adopts deionized water and anhydrous ethanol to wash alternately 3 times; and the drying temperature is 80℃.
[0011] Preferably, in step S3, the calcination temperature is 600-900℃, and the calcination time is 10h.
[0012] Preferably, in step S1, the magnesium source is magnesium acetate; the cobalt source is cobalt acetate tetrahydrate; the nickel source is nickel acetate tetrahydrate; the copper source is copper acetate monohydrate; the zinc source is zinc acetate dihydrate; and the sodium source is sodium tungstate dihydrate.
[0013] Preferably, in step S1, the stirring time is 15min.
[0014] Preferably, in step S2, the ultrasonic time is 20min.
[0015] The third aspect of the present application further provides a negative electrode sheet, which contains the high-entropy tungstate material for lithium ion battery negative electrode or the high-entropy tungstate material for lithium ion battery negative electrode prepared by the above method.
[0016] The fourth aspect of the present application further provides a battery, which comprises the above negative electrode sheet, and further comprises a battery shell, a positive electrode sheet, a separator and an electrolyte.
[0017] Compared with the prior art, the present application has the following beneficial effects:
[0018] 1. The high-entropy tungstate material for lithium ion battery negative electrode prepared by the method of the present application has the advantage that the hydrothermal reaction makes the material evenly heated, so that the prepared high-entropy oxide material has a regular nanosphere structure, which can increase the transmission channel of lithium ions;
[0019] 2. The high-entropy tungstate material for lithium ion battery negative electrode prepared by the method of the present application has uniform and small particle size, and the size is about 100-200nm, which can effectively accelerate the transmission of ions and electrons, so that the synthesized material has more excellent capacity and rate performance for lithium ion battery negative electrode;
[0020] 3、The preparation method used in the application is simple, fast and uses low-cost raw materials; first, low-cost and readily available starting materials are selected, the synthesis method does not require expensive raw materials, devices or complex synthesis conditions, greatly reducing the complexity and cost of the preparation process, and has practical application value.
[0021] 4、The application prepared a negative electrode material with excellent electrochemical performance. In the electrochemical test, the material showed high discharge specific capacity and good cycle life, which indicated that the material had potential in lithium ion battery application and could meet the performance and cycle life requirements. BRIEF DESCRIPTION OF DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the description of the application or prior art. Obviously, the drawings described below are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.
[0023] Figure 1 XRD spectrum of high-entropy tungstate material for lithium ion battery negative electrode of the application example 1-4;
[0024] Figure 2 Rate graph of high-entropy tungstate material for lithium ion battery negative electrode of the application example 1-4;
[0025] Figure 3 Long cycle graph of high-entropy tungstate material for lithium ion battery negative electrode of the application example 1-4;
[0026] Figure 4 SEM graph of high-entropy tungstate material for lithium ion battery negative electrode of the application example 3. DETAILED DESCRIPTION
[0027] In order to make the purpose, technical solutions and advantages of the application more clear, the technical solutions in the application will be described clearly and completely below in combination with the drawings in the application. Obviously, the described embodiments are part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the application.
[0028] The experimental methods used in the embodiments of the application are conventional methods unless otherwise specified.
[0029] In the following examples, all raw materials can be prepared by commercial or conventional methods, unless otherwise specified, as follows: magnesium acetate (Shanghai Macklin Biotech Co., Ltd., 99%), cobalt acetate tetrahydrate (Shanghai Macklin Biotech Co., Ltd., 99%), nickel acetate tetrahydrate (Jiangsu Qiangsheng Functional Chemical Co., Ltd., analytical pure), copper acetate monohydrate (Wuxi Zhanwang Chemical Reagent Co., Ltd., chemical pure), zinc acetate dihydrate (Shanghai Macklin Biotech Co., Ltd., 99%), sodium tungstate dihydrate (Shanghai Macklin Biotech Co., Ltd., 99%).
[0030] Example 1
[0031] First, according to the molar ratio of 1:1:1:1:1:1 of the chemical molecular formula of the high-entropy tungstate material for lithium ion battery anode, 0.581 g of magnesium acetate, 1.001 g of cobalt acetate, 1.005 g of nickel acetate, 0.807 g of copper acetate, 0.887 g of zinc acetate, and 1.326 g of sodium tungstate were weighed, respectively, and dissolved in 30 ml of deionized water to obtain solution A, and sodium tungstate was dissolved in 30 ml of deionized water to obtain solution B. Then, solution A and solution B were placed on a magnetic stirrer for stirring. Then, after solution A and solution B were stirred for 15 min, respectively, solution A was added to solution B to obtain solution C, and ultrasonic treatment was performed for 20 min. After the ultrasonic treatment was completed, solution C was slowly poured into a polytetrafluoroethylene liner, placed in a steel jacket, and tightened. The steel jacket was placed in a 180°C air drying oven for 10 h for hydrothermal reaction, and the precipitate generated by the reaction was recorded as precursor D. After the precursor D was naturally cooled to room temperature, it was taken out, centrifuged at 4000 r / min for 2 min, washed with deionized water and anhydrous ethanol alternately for 3 times, and placed in a 80°C air drying oven for drying to obtain the precursor E of the high-entropy tungstate material for battery anode. Finally, the precursor powder E was loaded into a quartz boat and placed in a muffle furnace for calcination at 600°C for 10 h in an air atmosphere, and after the furnace was cooled, the (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )WO4 anode material was finally obtained.
[0032] Example 2
[0033] First, according to the molar ratio of 1:1:1:1:1:1 of the chemical molecular formula of the high-entropy tungstate material for lithium ion battery negative electrode, magnesium acetate, cobalt acetate, nickel acetate, copper acetate, zinc acetate, and sodium tungstate were weighed at 0.581 g, 1.001 g, 1.005 g, 0.807 g, 0.887 g, and 1.326 g, respectively, and the above acetate was dissolved in 30 ml of deionized water to obtain solution A, and sodium tungstate was dissolved in 30 ml of deionized water to obtain solution B. Then, solution A and solution B were placed on a magnetic stirrer for stirring. Then, after solution A and solution B were stirred for 15 min, respectively, solution A was added to solution B to obtain solution C, and ultrasonic treatment was performed for 20 min. After the ultrasonic treatment was completed, solution C was slowly poured into a polytetrafluoroethylene liner, placed in a steel sleeve, and tightened. The steel sleeve was placed in a 180°C air drying oven for 10 h for hydrothermal reaction, and the precipitate generated by the reaction was recorded as precursor D. After the precursor D was naturally cooled to room temperature, it was taken out, centrifuged at 4000 r / min for 2 min, washed with deionized water and anhydrous ethanol alternately for 3 times, and placed in a 80°C air drying oven for drying to obtain the precursor E of the high-entropy tungstate material for battery negative electrode. Finally, the precursor powder E was loaded into a quartz boat and placed in a muffle furnace for calcination at 700°C for 10 h in an air atmosphere, and after the furnace was cooled, the (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )WO4 negative electrode material was finally obtained.
[0034] Example 3
[0035] First, according to the molar ratio of 1:1:1:1:1:1 of the chemical molecular formula of the high-entropy tungstate material for lithium ion battery negative electrode, magnesium acetate, cobalt acetate, nickel acetate, copper acetate, zinc acetate, and sodium tungstate were weighed at 0.581 g, 1.001 g, 1.005 g, 0.807 g, 0.887 g, and 1.326 g, respectively, and the above acetate was dissolved in 30 ml of deionized water to obtain solution A, and sodium tungstate was dissolved in 30 ml of deionized water to obtain solution B. Then, solution A and solution B were placed on a magnetic stirrer for stirring. Then, after solution A and solution B were stirred for 15 min, respectively, solution A was added to solution B to obtain solution C, and ultrasonic treatment was performed for 20 min. After the ultrasonic treatment was completed, solution C was slowly poured into a polytetrafluoroethylene liner, placed in a steel sleeve, and tightened. The steel sleeve was placed in a 180°C air drying oven for 10 h for hydrothermal reaction, and the precipitate generated by the reaction was recorded as precursor D. After the precursor D was naturally cooled to room temperature, it was taken out, centrifuged at 4000 r / min for 2 min, washed with deionized water and anhydrous ethanol alternately for 3 times, and placed in a 80°C air drying oven for drying to obtain the precursor E of the high-entropy tungstate material for battery negative electrode. Finally, the precursor powder E was loaded into a quartz boat and placed in a muffle furnace for calcination at 800°C for 10 h in an air atmosphere, and after the furnace was cooled, the (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )WO4 negative electrode material was finally obtained.
[0036] Example 4
[0037] First, according to the molar ratio of 1:1:1:1:1:1 of the chemical molecular formula of the high-entropy tungstate material for lithium ion battery negative electrode, magnesium acetate, cobalt acetate, nickel acetate, copper acetate, zinc acetate, and sodium tungstate were weighed at 0.581 g, 1.001 g, 1.005 g, 0.807 g, 0.887 g, and 1.326 g, respectively, and the above acetate salts were dissolved in 30 ml of deionized water to obtain solution A, and sodium tungstate was dissolved in 30 ml of deionized water to obtain solution B. Then, solution A and solution B were placed on a magnetic stirrer for stirring. Then, after stirring solution A and solution B for 15 min, respectively, solution A was added to solution B to obtain solution C, and ultrasonic treatment was performed for 20 min. After the ultrasonic treatment was completed, solution C was slowly poured into a polytetrafluoroethylene liner, placed in a steel sleeve, and tightened. The steel sleeve was placed in a 180°C air drying oven for 10 h for hydrothermal reaction, and the precipitate generated by the reaction was recorded as precursor D. After naturally cooling to room temperature, the precursor D was taken out, centrifuged at 4000 r / min for 2 min, washed with deionized water and anhydrous ethanol alternately for 3 times, and placed in a 80°C air drying oven for drying to obtain the precursor E of the high-entropy tungstate material for battery negative electrode. Finally, the precursor powder E was loaded into a quartz boat and placed in a muffle furnace for calcination at 900°C for 10 h in an air atmosphere, and after the furnace was cooled, the (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )WO4 negative electrode material was finally obtained.
[0038] Example 5 XRD test
[0039] The materials prepared in Examples 1-4 were subjected to XRD test, and the test results are shown in Figure 1 From Figure 1 it can be seen that the diffraction peaks at diffraction angles (2θ) of 15.58°, 18.98°, 23.82°, 24.65°, 30.63°, 31.45°, 36.30°, 36.43°, 38.52°, 41.28°, 41.38°, 52.07°, and 54.06° correspond to the characteristic peaks of PDF#15-0867, respectively, and no other impurity phase is found, indicating that the (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )WO4 negative electrode material has high crystallinity. It is proved that the synthesized product achieves the expected goal.
[0040] Example 6 SEM test
[0041] The material prepared in Example 3 was subjected to SEM test, and the test results are shown in Figure 4 From Figure 4 it can be seen that the (Mg0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )WO4 negative electrode material powder is attached to some polyhedral column by many small spherical nanoparticles. The particle size is uniform, the morphology is solid irregular body, and the powder particle size is micro-nano level, which shows that the material has good specific surface area and excellent electrochemical performance.
[0042] Example 7 battery performance test
[0043] Use the materials of examples 1-4 as electrode materials of lithium ion battery
[0044] (1) Mix the materials of examples 1-4 with conductive agent Super P and PVDF respectively according to the mass ratio of 8:1:1, grind and mix uniformly in a mortar, add appropriate amount of NMP and coat on copper foil, place in vacuum drying oven at 80℃ for 12h, get battery negative electrode sheet after rolling and cutting treatment;
[0045] (2) Use metal lithium sheet as counter electrode, make 2016 type button cell in argon-filled glove box, use celgard2250 separator, use 1M LiPF6 / EC:DEC(volumeratio 1:1) as electrolyte, test the battery performance of the prepared 2016 type button cell on the blue electric test system. Test the electrochemical energy storage performance of the prepared lithium ion battery.
[0046] (3) The charge and discharge range is 0.01-3V, the charge and discharge rate is set to trapezoidal rate of 500mA / g, 1000mA / g, 2000mA / g, 3000mA / g, 5000mA / g, 3000mA / g, 2000mA / g, 1000mA / g, 500mA / g. Test the electrochemical energy storage performance of the prepared lithium ion battery, as shown in Figure 2 and Figure 3 .
[0047] by Figure 2It can be seen that the high entropy tungstate material for the negative electrode of lithium ion battery prepared by Examples 1-4 is used. It is found that Example 3 has a charge capacity of about 789.2mAh / g, 649.5mAh / g, 552.7mAh / g, 472.1mAh / g, 408.1mAh / g, 440mAh / g, 482.8mAh / g, 539.2mAh / g, and 668mAh / g at different charge and discharge trapezoidal current densities of 500mA / g, 1000mA / g, 2000mA / g, 3000mA / g, 500mA / g, and the rate performance is significantly better than that of other examples, indicating that the (MgO) synthesized at 800℃ has a high charge capacity of about 789.2mAh / g, 649.5mAh / g, 552.7mAh / g, 472.1mAh / g, 408.1mAh / g, 440mAh / g, 482.8mAh / g, 539.2mAh / g, and 668mAh / g. 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 ) The lithium-ion battery made of WO4 negative electrode material has good rate performance and high coulombic efficiency.
[0048] Depend on Figure 3 It can be seen that after 80 cycles at a current density of 500 mA / g, the specific capacity of the high entropy tungstate material for lithium-ion battery negative electrode prepared by Example 3 is still about 388.4 mAh / g, and the cycle performance is better than that of other examples. 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )The lithium-ion battery made of WO4 negative electrode material has good cycle performance and weak attenuation rate.
[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A high entropy tungstate material for a lithium ion battery negative electrode, characterized in that: The chemical formula of the high entropy tungstate material for the negative electrode of the lithium ion battery is (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )WO4.
2. A method for preparing the high entropy tungstate material for lithium ion battery negative electrode according to claim 1, characterized in that: The following steps are involved: S1. Dissolve a magnesium source, a cobalt source, a nickel source, a copper source, and a zinc source in deionized water, which is referred to as solution A; dissolve a sodium source in deionized water, which is referred to as solution B; and stir the solutions A and B for a period of time; S2, adding the stirred solution A to solution B to obtain solution C, and ultrasonically treating the solution C for a period of time; S3. The solution C after ultrasonic treatment is subjected to a hydrothermal reaction. The precipitate obtained after the reaction is completed is recorded as a precursor D; the precursor D is naturally cooled to room temperature and then taken out, centrifuged, washed, and dried to obtain a precursor E; the precursor E is calcined to obtain a high entropy tungstate material for a negative electrode of a lithium-ion battery.
3. The method for preparing a high entropy tungstate material for a lithium ion battery negative electrode according to claim 2, wherein: In step S3, the hydrothermal reaction temperature is 180° C., and the hydrothermal reaction time is 10 h.
4. The method for preparing a high entropy tungstate material for a lithium ion battery negative electrode according to claim 2, wherein: In step S3, the centrifugal speed is 4000 r / min, and the centrifugal time is 2 min; the washing is performed by alternating deionized water and anhydrous ethanol for 3 times; and the drying temperature is 80°C.
5. The method for preparing a high entropy tungstate material for a negative electrode of a lithium ion battery according to claim 2, wherein: In step S3, the calcination temperature is 600-900° C., and the calcination time is 10 hours.
6. The method for preparing a high entropy tungstate material for a negative electrode of a lithium ion battery according to claim 2, wherein: In step S1, the magnesium source is magnesium acetate; the cobalt source is cobalt acetate tetrahydrate; the nickel source is nickel acetate tetrahydrate; the copper source is copper acetate monohydrate; the zinc source is zinc acetate dihydrate; and the sodium source is sodium tungstate dihydrate.
7. The method for preparing a high entropy tungstate material for a lithium ion battery negative electrode according to claim 2, wherein: In step S1, the stirring time is 15 minutes.
8. The method for preparing a high entropy tungstate material for a lithium ion battery negative electrode according to claim 2, wherein: In step S2, the ultrasonic time is 20 minutes.
9. A negative electrode sheet, characterized in that: The negative electrode sheet contains the high-entropy tungstate material for a negative electrode of a lithium-ion battery according to claim 1 or the high-entropy tungstate material for a negative electrode of a lithium-ion battery prepared by the method of any one of claims 2 to 8.
10. A battery, characterized in that: The invention comprises the negative electrode sheet according to claim 9, and further comprises a battery casing, a positive electrode sheet, a separator and an electrolyte.