A kind of MnV based on tetrabutylammonium coating 13 Preparation method and application of cluster aqueous zinc-ion battery positive electrode material

Abstract

A MnV cluster coated based on tetrabutylammonium 13 The preparation method and application of a cluster aqueous zinc ion battery positive electrode material belong to the field of aqueous zinc ion batteries. The present application solves the problems of limited phase stability, limited ion transmission, excess of crystallization water and low pseudo-capacitance contribution rate of existing polyoxometalate as the positive electrode material of the aqueous zinc ion battery, which leads to low discharge capacity and durability. Method: I. Preparation of MnV 13 solution; II. Preparation of tetrabutylammonium chloride solution; III. Slowly add MnV 13 solution to tetrabutylammonium chloride solution, stir and dry; IV. Calcination. Application: It is used for the preparation of the positive electrode of the aqueous zinc ion battery. The present application is used for the preparation and application of MnV 13 cluster coated based on tetrabutylammonium.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of aqueous zinc ion batteries. BACKGROUND

[0002] With the continuous growth of global energy demand and the gradual depletion of fossil energy, the demand for low-carbon economy is increasingly urgent, which promotes the profound change of energy consumption structure and gives birth to the trend of transformation from traditional fossil fuels to renewable energy and sustainable alternative energy. As a key tool to support sustainable and intermittent energy utilization, electrochemical energy storage systems have become an important technology for fast and efficient energy storage and release. Among them, lithium ion batteries (LIB) have shown good adaptability and reliability in many fields such as portable devices and electric vehicles due to their high energy density, long cycle life, low self-discharge rate and fast charging capability. However, LIBs face some limitations in grid-scale energy storage, such as high cost due to the scarcity of lithium resources, potential environmental hazards and safety hazards of flammable organic electrolyte, etc. Compared with the above battery systems, aqueous zinc ion batteries have great potential in the field of future large-scale energy storage due to their high safety, environmental friendliness, abundant zinc reserves, low cost and high energy density.

[0003] Multi-metal oxide clusters have been widely regarded as promising candidates for aqueous zinc ion battery anode materials in recent years due to their rich redox properties, precise molecular-level structure and excellent electronic controllability. Among them, vanadium-based multi-metal oxide clusters have attracted much attention due to their multi-electron reaction mechanism and complex and rich redox kinetic behavior. However, their direct application in aqueous electrolyte is affected by many limiting factors, such as insufficient phase stability, limited ion transport and excess crystal water, which significantly restrict the realization of the theoretical capacity and cycle stability of the material. SUMMARY

[0004] The present application aims to solve the problems of existing multi-metal oxide clusters as aqueous zinc ion battery anode materials, such as limited phase stability, limited ion transport, excess crystal water and low pseudo-capacitance contribution rate, which result in low discharge capacity and durability, and further provides a preparation method and application of a MnV 13 cluster aqueous zinc ion battery anode material based on tetrabutylammonium coating.

[0005] A preparation method of a MnV 13 cluster aqueous zinc ion battery anode material based on tetrabutylammonium coating.

[0006] I. Dissolve MnV 13 in deionized water to obtain a MnV 13 solution;

[0007] 2. Dissolve tetrabutylammonium chloride in deionized water to obtain a tetrabutylammonium chloride solution;

[0008] III. Under stirring conditions, MnV 13 The solution was slowly added to a tetrabutylammonium chloride solution and stirred. The mixture was then concentrated, centrifuged, washed, and dried to obtain a dry powder.

[0009] IV. Under an argon atmosphere, the dry powder was calcined to obtain tetrabutylammonium-coated MnV. 13 That is, to complete the MnV based on tetrabutylammonium coating 13 Preparation method of aqueous zinc-ion battery cathode material;

[0010] The tetrabutylammonium-coated MnV 13 The chemical formula is (NH4)2(C 16 H 36 N)5MnV 13 O 38 .

[0011] Application: It is used to prepare the positive electrode for aqueous zinc-ion batteries.

[0012] The beneficial effects of this invention are:

[0013] 1. This invention discloses a method for coating MnV with tetrabutylammonium. 13 A method for preparing high-performance pseudocapacitive cathode materials, which first involves mixing materials containing TBA cations and MnV 13 A solution of anions is prepared, and then TBA cations are simply coated with MnV in aqueous solution using an ion exchange reaction. 13 Cluster (TBA-MnV) 13 The positively charged cation portion interacts with MnV. 13 The negatively charged anions on the clusters attract each other electrostatically, forming a stable structure. Calcination then ensures complete removal of residual moisture. Removal of crystal water enhances the activity of the polyoxometalate clusters. Simultaneously, due to MnV... 13 The innovative composite with TBA introduces structural disorder and reduces crystallinity, all of which synergistically enhance the material's electrochemical activity and stability, thereby improving its electrochemical energy storage performance. The aforementioned preparation method is simple, easy to operate and repeat, and has broad applicability, making it suitable for large-scale production and showing promising application prospects.

[0014] 2. This invention also discloses the above-mentioned tetrabutylammonium-coated MnV 13 Application of high-performance pseudocapacitive materials in the cathode of aqueous zinc-ion batteries. When used as a cathode material in aqueous zinc-ion batteries, this material can promote the growth of Zn by enhancing the contribution of surface pseudocapacitance. 2+Rapid ion storage ensures fast electrochemical reaction kinetics (variable scan rate CV calculations show that the capacitance contribution gradually increases with increasing scan rate, and is greater than that of MnV under the same conditions). 13 (Electrode). Furthermore, due to the coating effect of TBA in the material, when used as a cathode material for aqueous zinc-ion batteries, this material significantly improves the cycle stability of the battery system (after 2700 cycles at a current density of 1 A / g, TBA-MnV... 13 The specific capacity of the positive electrode remains as high as 258.7 mAh g. -1 In contrast to MnV 13 After 2700 cycles, the specific capacity was only 19.7 mAh g. -1 In summary, MnV coated with tetrabutylammonium... 13 The kinetic and electrochemical performance of high-performance pseudocapacitor materials in aqueous zinc-ion batteries has been significantly improved. Attached Figure Description

[0015] Figure 1 TBA-MnV prepared in Example 1 13 With MnV 13 Comparison of X-ray diffraction images;

[0016] Figure 2 TBA-MnV prepared in Example 1 13 TBA and MnV 13 Infrared spectrum;

[0017] Figure 3 TBA-MnV prepared in Example 1 13 Transmission electron microscope images;

[0018] Figure 4 TBA-MnV prepared in Example 1 13 High-resolution transmission electron microscope images;

[0019] Figure 5 TBA-MnV prepared in Example 1 13 Elemental distribution diagram of energy-dispersive X-ray spectra;

[0020] Figure 6 TBA-MnV prepared in Example 1 13 Thermogravimetric analysis curves under oxygen atmosphere;

[0021] Figure 7 Example 3 uses TBA-MnV 13 and MnV 13 The coin cell assembled with the prepared aqueous zinc-ion battery cathode was tested at a voltage of 0.2V–1.8V and a scan rate of 0.5mV / s.-1 Cyclic voltammograms of the prepared water-based zinc ion battery cathode assembled button cell at different scan rates;

[0022] Figure 8 TBA-MnV was used for Example Three 13 and MnV 13 Charge-discharge curves of the prepared water-based zinc ion battery cathode assembled button cell;

[0023] Figure 9 TBA-MnV was used for Example Three 13 and MnV 13 Rate performance test curves of the prepared water-based zinc ion battery cathode assembled button cell at a current density of 0.2 Ag -1 ~ 9 Ag -1 ;

[0024] Figure 10 TBA-MnV was used for Example Three 13 and MnV 13 Electrochemical impedance spectroscopy test of the prepared water-based zinc ion battery cathode assembled button cell;

[0025] Figure 11 TBA-MnV was used for Example Three 13 CV curves of the prepared water-based zinc ion battery cathode assembled button cell measured at different scan rates;

[0026] Figure 12 b values of the four groups of redox peaks in Figure 11 ;

[0027] Figure 13 TBA-MnV was used for Example Three 13 Diffusion / capacitance contribution ratio calculated after CV curves of the prepared water-based zinc ion battery cathode assembled button cell measured at different scan rates;

[0028] Figure 14 MnV was used for Example Three 13 CV curves of the prepared water-based zinc ion battery cathode assembled button cell measured at different scan rates;

[0029] Figure 15 b values of the four groups of redox peaks in Figure 14 ;

[0030] Figure 16 MnV was used for Example Three 13 Diffusion / capacitance contribution ratio calculated after CV curves of the prepared water-based zinc ion battery cathode assembled button cell measured at different scan rates;

[0031] Figure 17 TBA-MnV was used for Example Three13 The coin cell assembled with the aqueous zinc-ion battery cathode was initially TBA-MnV. 13 V 2p X-ray photoelectron spectrum;

[0032] Figure 18 Example 3 uses TBA-MnV 13 The coin cell assembled with the aqueous zinc-ion battery cathode exhibits TBA-MnV during the discharge phase. 13 V 2p X-ray photoelectron spectrum;

[0033] Figure 19 Example 3 uses TBA-MnV 13 The button cell assembled with the aqueous zinc-ion battery cathode exhibits TBA-MnV during the charging phase. 13 V 2p X-ray photoelectron spectrum;

[0034] Figure 20 Example 3 uses MnV 13 The coin cell assembled with the positive electrode of the aqueous zinc-ion battery has an initial MnV value. 13 V 2p X-ray photoelectron spectrum;

[0035] Figure 21 To use MnV 13 The coin cell assembled with the positive electrode of the prepared aqueous zinc-ion battery exhibits MnV during the discharge phase. 13 V 2p X-ray photoelectron spectrum;

[0036] Figure 22 To adopt MnV 13 The coin cell assembled with the positive electrode of the prepared aqueous zinc-ion battery exhibits MnV during the charging phase. 13 V 2p X-ray photoelectron spectrum;

[0037] Figure 23 Example 3 uses TBA-MnV 13 The coin cell assembled with the prepared aqueous zinc-ion battery cathode exhibited its second charge-discharge (activation) process. 51 V nuclear magnetic resonance spectrum;

[0038] Figure 24 Example 3 uses TBA-MnV 13 The coin cell assembled with the prepared aqueous zinc-ion battery cathode underwent its twelfth cycle (after activation). 51 V nuclear magnetic resonance spectrum;

[0039] Figure 25 Example 3 uses TBA-MnV 13The prepared water-based zinc ion battery positive electrode assembled button cell in the discharge stage TBA-MnV 13 Zn 2p X-ray photoelectron spectrum of the positive electrode;

[0040] Figure 26 TBA-MnV was used for Example Three 13 The prepared water-based zinc ion battery positive electrode assembled button cell in the charge stage TBA-MnV 13 Zn 2p X-ray photoelectron spectrum of the positive electrode;

[0041] Figure 27 MnV was used for Example Three 13 The prepared water-based zinc ion battery positive electrode assembled button cell in the discharge stage TBA-MnV -1 The cycle performance graph of the prepared water-based zinc ion battery positive electrode assembled button cell cycled 2700 times at a current density of 1.0 Ag

[0042] Figure 28 TBA-MnV was used for Example Three 13 The prepared water-based zinc ion battery positive electrode assembled button cell in the charge stage TBA-MnV -1 The cycle performance graph of the prepared water-based zinc ion battery positive electrode assembled button cell cycled 2700 times at a current density of 1.0 Ag

[0043] Figure 29 TBA-MnV was used for Example Three 13 and MnV 13 The prepared water-based zinc ion battery positive electrode assembled button cell in the discharge stage TBA-MnV -1 The cycle performance graph of the prepared water-based zinc ion battery positive electrode assembled button cell cycled 2700 times at a current density of 1.0 Ag

[0044] Figure 30 TBA-MnV was used for Example Three 13 The prepared water-based zinc ion battery positive electrode assembled button cell in the charge stage TBA-MnV

[0045] Figure 31 TBA-MnV was used for Example Three 13 The prepared water-based zinc ion battery positive electrode assembled button cell in the discharge stage TBA-MnV

[0046] Figure 32 MnV was used for Example Three 13 The prepared water-based zinc ion battery positive electrode assembled button cell in the charge stage TBA-MnV DETAILED DESCRIPTION

[0047] DETAILED DESCRIPTION ONE: The embodiment is a MnV 13The preparation method of the cluster aqueous zinc ion battery positive electrode material is carried out according to the following steps:

[0048] I. Dissolve MnV 13 in deionized water to obtain a MnV 13 solution;

[0049] II. Dissolve tetrabutylammonium chloride in deionized water to obtain a tetrabutylammonium chloride solution;

[0050] III. Under stirring, slowly add the MnV 13 solution into the tetrabutylammonium chloride solution, then stir, concentrate the mixed solution, centrifugal wash and dry to obtain a dry powder;

[0051] IV. Under an argon atmosphere, calcine the dry powder to obtain a tetrabutylammonium-coated MnV 13 , that is, the preparation method of the cluster aqueous zinc ion battery positive electrode material based on tetrabutylammonium-coated MnV 13 is completed.

[0052] The chemical formula of the tetrabutylammonium-coated MnV 13 is (NH4)2(C 16 H 36 N)5MnV 13 O 38 .

[0053] The positive electrode of the tetrabutylammonium-coated MnV 13 (TBA-MnV 13 ) of the present specific embodiment is a strategy that aims to take advantage of the structure and electronic properties of MnV 13 while improving its stability and ion diffusion pathways through coating. Compared with traditional intercalation electrodes, it significantly improves the performance of aqueous zinc ion batteries through an efficient pseudo-capacitive mechanism, achieving fast and stable Zn 2+ insertion while not affecting the structural integrity of the electrode. The positive electrode material is low in cost, safe and environmentally friendly, and easy to scale up.

[0054] The beneficial effects of the present embodiment are:

[0055] 1. The present embodiment discloses a preparation method of a high-performance pseudo-capacitive positive electrode material coated with tetrabutylammonium-coated MnV 13 . The method first mixes a solution containing TBA cations and MnV 13 anions, and then uses an ion exchange reaction in an aqueous solution to simply coat MnV 13 clusters (TBA-MnV 13 ) with TBA cations. The positively charged cation part is combined with MnV 13The negative anions on the cluster are electrostatically attracted to form a stable structure, and the residual water is completely removed by calcination. The removal of crystal water can improve the activity of polyoxometalate. At the same time, due to the introduction of TBA, the structure is disordered, the crystallinity is reduced, and all these synergistically enhance the electrochemical activity and stability of the material, and improve the electrochemical energy storage performance of the material. 13 The preparation method is simple, easy to operate and repeat, has universality, can be used for large-scale production, and has good application prospect.

[0056] 2. The embodiment also discloses application of the above-mentioned high-performance pseudo-capacitive material of tetrabutylammonium-coated MnV 13 in a water-based zinc ion battery positive electrode. When the material is used in a water-based zinc ion battery positive electrode material, the rapid storage of Zn 2+ ions can be promoted to ensure fast electrochemical reaction kinetics (the variable scan rate CV calculation result shows that the capacitance contribution gradually increases with the increase of the scan rate, and is greater than that of MnV 13 electrode under the same conditions). In addition, due to the coating effect of TBA in the material, when the material is used in a water-based zinc ion battery positive electrode material, the cycle stability of the battery system is significantly improved (the specific capacity of the TBA-MnV 13 positive electrode is still as high as 258.7 mAh g -1 after 2700 cycles at a current density of 1 A / g; while the specific capacity of the comparative MnV 13 is only 19.7 mAh g -1 after 2700 cycles). In summary, the kinetics and electrochemical performance of the high-performance pseudo-capacitive material of MnV 13 coated with tetrabutylammonium have been significantly improved.

[0057] Specific embodiment two: different from the specific embodiment one, the mass and volume ratio of MnV 13 to deionized water in step one is 1g:(20-30)mL. The others are the same as the specific embodiment one.

[0058] Specific embodiment three: different from the specific embodiment one or two, the mass and volume ratio of tetrabutylammonium chloride to deionized water in step two is 1g:(50-60)mL. The others are the same as the specific embodiment one or two.

[0059] Specific embodiment four: different from the specific embodiment one to three, the volume ratio of MnV 13 solution to tetrabutylammonium chloride solution in step three is 1:(3-4). The others are the same as the specific embodiment one to three.

[0060] Specific implementation five: the difference between this implementation and one of the specific implementations one to four is that: in step three, the concentration of the mixed solution is specifically concentrated by using a rotary evaporator under the condition of a temperature of 50℃-60℃ and a rotation speed of 100rpm-120rpm until the solvent is completely evaporated; the centrifugal washing in step three is specifically centrifugal washing for 5min-10min under the condition of a rotation speed of 8000rpm-10000rpm, and the centrifugal washing is repeated ≥3 times. The others are the same as specific implementation one to four. 13 The solution is slowly added to the tetrabutylammonium chloride solution and stirred for 1h-2h. The others are the same as specific implementation one to four.

[0061] Specific implementation six: the difference between this implementation and one of the specific implementations one to five is that: in step three, the concentration of the mixed solution is specifically concentrated by using a rotary evaporator under the condition of a temperature of 50℃-60℃ and a rotation speed of 100rpm-120rpm until the solvent is completely evaporated; the centrifugal washing in step three is specifically centrifugal washing for 5min-10min under the condition of a rotation speed of 8000rpm-10000rpm, and the centrifugal washing is repeated ≥3 times. The others are the same as specific implementation one to five.

[0062] Specific implementation seven: the difference between this implementation and one of the specific implementations one to six is that: the drying in step three is specifically vacuum drying for 12h-16h under the condition of a temperature of 50℃-60℃. The others are the same as specific implementation one to six.

[0063] Specific implementation eight: the difference between this implementation and one of the specific implementations one to seven is that: in step four, the temperature is raised to 200℃-250℃ at a temperature raising speed of 3℃ / min-5℃ / min under an argon atmosphere, and then calcined under the condition of an argon atmosphere and a temperature of 200℃-250℃ for 5h-6h. The others are the same as specific implementation one to seven.

[0064] Specific implementation nine: one of the specific implementations is a MnV 13 cluster coated by tetrabutylammonium, which is used for preparing a water-based zinc ion battery positive electrode.

[0065] Specific implementation ten: the difference between this implementation and specific implementation nine is that: it is used for preparing a water-based zinc ion battery positive electrode, which is specifically prepared by the following steps:

[0066] It is used for preparing a water-based zinc ion battery positive electrode, which is specifically prepared by the following steps:

[0067] MnV 13 , a conductive agent, a binder and N-methyl pyrrolidone are mixed to obtain a homogenate, and the homogenate is coated on the surface of the positive electrode current collector according to a coating amount of 0.7mg / cm 2 -1.0mg / cm 2The homogenate is coated on the current collector, and finally dried to obtain a positive electrode of aqueous zinc ion battery;

[0068] The tetrabutylammonium-coated MnV 13 The mass ratio of the conductive agent to the binder is 7:(1-1.5); the tetrabutylammonium-coated MnV 13 The mass ratio of the conductive agent to the binder is 7:(1-1.5); the tetrabutylammonium-coated MnV 13 The mass ratio of the conductive agent to the binder is 7:(1-1.5); the tetrabutylammonium-coated MnV

[0069] The beneficial effects of the present application are verified by the following examples:

[0070] Example 1:

[0071] A tetrabutylammonium-coated MnV 13 The preparation method of the cluster aqueous zinc ion battery positive electrode material is carried out according to the following steps:

[0072] I. 2.178g of MnV 13 is dissolved in 50mL of deionized water to obtain a MnV 13 solution;

[0073] The structural formula of the MnV 13 is (NH4)7MnV 13 O 38 ;

[0074] II. 2.918g of tetrabutylammonium chloride (TBA-Cl) is dissolved in 150mL of deionized water to obtain a tetrabutylammonium chloride solution;

[0075] III. Under the condition of a rotation speed of 500rpm, 50mL of the MnV 13 solution is slowly added to the 150mL tetrabutylammonium chloride solution at an addition speed of 1mL / min, and stirred for 1h, and then the mixed solution is concentrated, centrifuged, washed and dried to obtain a dry powder;

[0076] IV. Under an argon atmosphere, the dry powder is heated to 200℃ at a heating rate of 5℃ / min, and then calcined under an argon atmosphere and at a temperature of 200℃ for 5h to obtain a tetrabutylammonium-coated MnV 13 , i.e. TBA-MnV 13 ;

[0077] The chemical formula of the tetrabutylammonium-coated MnV 13 is (NH4)2(C 16 H 36 N)5MnV13 O 38 .

[0078] The concentration of the mixed solution mentioned in step three is specifically achieved by using a rotary evaporator to concentrate the mixed solution until the solvent is completely evaporated at a temperature of 60°C and a rotation speed of 100 rpm.

[0079] The centrifugal washing described in step three specifically involves using deionized water and centrifuging at 8000 rpm for 10 minutes, and repeating the centrifugal washing process three times.

[0080] The drying process described in step three specifically involves vacuum drying at a temperature of 60°C for 12 hours.

[0081] Example 2: MnV based on tetrabutylammonium coating prepared in Example 1 13 The application of cluster-based aqueous zinc-ion battery cathode materials, specifically used in the preparation of aqueous zinc-ion battery cathodes, is carried out according to the following steps:

[0082] MnV coated with tetrabutylammonium 13 The conductive agent, binder, and N-methylpyrrolidone are mixed to obtain a slurry, and the coating amount is 1.0 mg / cm². 2 The slurry was coated onto the current collector and then dried in a vacuum oven at 60°C to obtain the positive electrode of the aqueous zinc-ion battery (a disc with a diameter of 10 mm).

[0083] The tetrabutylammonium-coated MnV 13 The mass ratio of the conductive agent to the conductive agent is 7:2; the tetrabutylammonium-coated MnV 13 The mass ratio of the binder to the MnV is 7:1; the tetrabutylammonium-coated MnV 13 The mass ratio of N-methylpyrrolidone to N-methylpyrrolidone is 1 g: 10 mL; the conductive agent is multi-walled carbon nanotubes; and the adhesive is polyvinylidene fluoride.

[0084] Comparative Experiment: This comparative experiment differs from Example 2 in that: MnV coated with tetrabutylammonium is used. 13 Replace with MnV 13 Everything else is the same as in Example 2.

[0085] Figure 1 TBA-MnV prepared in Example 1 13 With MnV 13 Comparison of X-ray diffraction images; through diffraction images, compared with MnV 13 In comparison, TBA-MnV prepared after coating 13 The crystallinity of the material is significantly reduced, which means that MnV 13In the complex, it transforms into an amorphous state, and the small-angle XRD pattern shows a distinct peak at 7.36°, corresponding to an inter-cluster spacing of ~1.2 nm. This size is similar to that of MnV coated with TBA cations. 13 The clusters are of uniform size and height, confirming MnV. 13 It is evenly coated with TBA.

[0086] Figure 2 TBA-MnV prepared in Example 1 13 TBA and MnV 13 The infrared spectrum was obtained; the infrared spectrum confirmed the presence of TBA and MnV. 13 Coexisting in TBA-MnV 13 In the complex, both TBA and MnV are present. 13 Comparison of characteristic peaks in infrared spectra of TBA-MnV 13 The significant peak position did not shift, indicating that the coating process involves physical interactions rather than chemical bonding, thus preserving MnV in the composite material. 13 And the independent characteristics of TBA.

[0087] Figure 3 TBA-MnV prepared in Example 1 13 Transmission electron microscope images; Figure 4 TBA-MnV prepared in Example 1 13 High-resolution transmission electron microscope images; TBA-MnV can be seen from the images. 13 The amorphous state of the composite material is consistent with the XRD results. Furthermore, the randomly arranged MnV atoms in the composite material can be clearly observed. 13 Clusters, this disordered arrangement, facilitates ion transport.

[0088] Figure 5 TBA-MnV prepared in Example 1 13 The elemental distribution diagram of the energy-dispersive X-ray spectrum is shown. The diagram reveals that C, N, Mn, V, and O are uniformly distributed throughout the composite material, confirming the presence of MnV. 13 It was successfully covered by TBA.

[0089] Figure 6 TBA-MnV prepared in Example 1 13 Thermogravimetric analysis curves under oxygen atmosphere; the curves reveal TBA-MnV 13 The two-step mass loss process, with the significant mass loss in the first stage (220℃~350℃) attributed to NH4 + Thermal decomposition of TBA accounts for 44% of the total mass loss; while the second stage (350℃~600℃) corresponds to NH4. +decomposition, accounting for 3%, supported by thermogravimetric analysis and organic elemental analysis 13 with the chemical formula (NH4)2(C 16 H 36 N)5MnV 13 O 38 .

[0090] Example 3: Assembling button cells with the positive electrodes of aqueous zinc-ion batteries prepared in Example 2 and comparative experiments: Take a piece of zinc sheet, polish the whole zinc sheet with sandpaper to remove the surface oxide layer, then wash it with ultrapure water, and then put it into a constant temperature drying oven at 60°C for drying. The dried zinc sheet is cut into a 10mm diameter disc on a slicing machine as the negative electrode. Glass fiber is used as the battery separator, 3M Zn(CF3SO3)2 is used as the electrolyte, and CR2032 type button cells are assembled in the order of negative electrode shell, spring, gasket, negative electrode sheet, separator, electrolyte, positive electrode sheet, and positive electrode shell in the air, and then packaged with a battery packaging machine.

[0091] Figure 7 Cyclic voltammograms of button cells assembled with the positive electrodes of aqueous zinc-ion batteries prepared in Example 3 using TBA-MnV 13 and MnV 13 at a voltage of 0.2V-1.8V and a scan rate of 0.5mVs -1 ; from the figure, it can be seen that the TBA-MnV 13 positive electrode exhibits two pairs of completely different redox peaks, respectively at ~1.16 / 0.85V and 0.88 / 0.48V (compared with Zn / Zn 2+ ), and the peaks are well overlapped in the subsequent cycles, which means its excellent redox reversibility and stability; as a comparison, the redox peaks of the MnV 13 positive electrode have a slight shift: 1.22 / 0.75V, 0.82 / 0.37V (compared with Zn / Zn 2 + ), and similar stable peak current, reflecting its inherent reversible redox behavior.

[0092] Figure 8 Charge-discharge curves of button cells assembled with the positive electrodes of aqueous zinc-ion batteries prepared in Example 3 using TBA-MnV 13 and MnV 13 ; from the figure, it can be seen that TBA-MnV 13 exhibits a significantly higher specific capacity of 399.6mAh g -1 , compared with MnV 13 which only has 275mAh g -1 ; in addition, it can also be found that TBA-MnV13 The operating voltage is also slightly higher, indicating that TBA is used to coat MnV. 13 This not only increases energy storage capacity but also improves reaction kinetics.

[0093] Figure 9 Example 3 uses TBA-MnV 13 and MnV 13 The coin cell assembled with the prepared aqueous zinc-ion battery cathode operates at a current density of 0.2 Ag. -1 ~9Ag -1 Rate performance test curve at 0.2Ag; -1 0.5Ag -1 1Ag -1 2A g -1 3Ag -1 5Ag -1 7Ag -1 and 9Ag -1 Below, TBA-MnV 13 It exhibits an average discharge specific capacity of 338.6 mAh g. -1 320.4mAh g -1 305.9mAh g -1 289.6mAh g -1 274.5mAh g -1 237.5mAh g -1 197.5mAh g -1 and 163.8mAh g -1 When the current density returns to 0.2Ag after high-rate cycling. -1 At that time, the specific capacity recovered to 316.1 mAh g. -1 This demonstrates excellent rate performance and structural stability. Furthermore, the battery performs well at 1Ag. -1 After 600 cycles at a current density, the specific capacity remained at 298.5 mAh g. -1 This reflects its exceptional cycle stability, compared to MnV. 13 The cathode consistently exhibited lower capacity across all current densities, demonstrating that TBA coating improved the electrochemical performance of the material.

[0094] Figure 10 Example 3 uses TBA-MnV 13 and MnV 13 Electrochemical impedance spectroscopy (EIS) was performed on a coin cell assembled with the prepared aqueous zinc-ion battery cathode; it was found that after 120 cycles, TBA-MnV... 13 The charge transfer resistance is significantly lower than that of MnV. 13, which confirmed its superior ion transport performance.

[0095] Figure 11 TBA-MnV was used for Example Three 13 CV curves of the prepared aqueous zinc-ion battery anode assembled button cell were measured at different scan rates; Figure 12 Figure 11 b values of the four sets of redox peaks in Example Three; combined with Figure 11 TBA-MnV 13 The b values of peaks 1 to 4 were 0.9426, 0.9820, 0.8402 and 0.9428 respectively, indicating that the charge storage mechanism was mainly based on the pseudo-capacitance mechanism.

[0096] Figure 13 TBA-MnV was used for Example Three 13 The diffusion / capacitance contribution ratio calculated after measuring the CV curves of the prepared aqueous zinc-ion battery anode assembled button cell at different scan rates;

[0097] Figure 14 MnV was used for Example Three 13 CV curves of the prepared aqueous zinc-ion battery anode assembled button cell were measured at different scan rates; Figure 15 Figure 14 b values of the four sets of redox peaks in Example Three; combined with Figure 14 MnV 13 The b values of the anode were lower, being 0.8302, 0.6089, 0.7921 and 0.6625 respectively, indicating that it was more dependent on the diffusion-controlled process.

[0098] Figure 16 MnV was used for Example Three 13 The diffusion / capacitance contribution ratio calculated after measuring the CV curves of the prepared aqueous zinc-ion battery anode assembled button cell at different scan rates; combined with Figure 13 It can be found by comparison that the battery with TBA-MnV 13 as the anode active material mainly has a charge storage mechanism based on the pseudo-capacitance mechanism, while the battery with MnV 13 as the anode active material has a charge storage mechanism more dependent on the diffusion-controlled process, and when the scan rate is 0.7 mV s -1 , the TBA-MnV 13 anode achieves a high capacitance contribution of up to 95%, highlighting its fast charge transfer kinetics and high Zn 2+ availability, and this high capacitance proportion gradually increases with the increase of the scan rate, which confirms that the TBA-coated MnV 13 by enhancing the surface pseudo-capacitance contribution, promotes fast Zn 2+ ​​Ion storage.

[0099] Figure 17 Example 3 uses TBA-MnV 13 The coin cell assembled with the aqueous zinc-ion battery cathode was initially TBA-MnV. 13 V 2p X-ray photoelectron spectrum; Figure 18 Example 3 uses TBA-MnV 13 The coin cell assembled with the aqueous zinc-ion battery cathode exhibits TBA-MnV during the discharge phase. 13 V 2p X-ray photoelectron spectrum; Figure 19 Example 3 uses TBA-MnV 13 The button cell assembled with the aqueous zinc-ion battery cathode exhibits TBA-MnV during the charging phase. 13 V 2p X-ray photoelectron spectrum; combined with Figure 17 , 18 It can be observed that initially, TBA-MnV 13 The positive electrode mainly contains V 5 + As the battery discharges to 0.2V, V 5+ Consumption and V 3+ and V 4+ The initial appearance indicates a multi-electron reduction process occurring with the insertion of zinc ions. As charging begins, the reduced vanadium atoms are oxidized back to higher valence states, while zinc ions undergo insertion / extraction during this process. This demonstrates the reversible valence cycle and the TBA-MnV... 13 Stable redox activity of electrode materials.

[0100] Figure 20 Example 3 uses MnV 13 The coin cell assembled with the positive electrode of the aqueous zinc-ion battery has an initial MnV value. 13 V 2p X-ray photoelectron spectrum; Figure 21 To adopt MnV 13 The coin cell assembled with the positive electrode of the prepared aqueous zinc-ion battery exhibits MnV during the discharge phase. 13 V 2p X-ray photoelectron spectrum; Figure 22 To adopt MnV 13 The coin cell assembled with the positive electrode of the prepared aqueous zinc-ion battery exhibits MnV during the charging phase. 13 V 2p X-ray photoelectron spectrum; combined with Figure 20 , 21 It can be seen that MnV tested under the same conditions 13 The positive electrode exhibits limited valence state regulation capability; after discharging to 0.2V, MnV 13 The main one is still V. 5+ and V4+ , almost no low-valent vanadium (V) species are formed, highlighting the crucial role of the TBA coating for further redox reactions and multi-electron transformations, thus enabling TBA-MnV 13 to outperform its MnV 13 counterpart in terms of redox activity and energy storage capacity.

[0101] Figure 23 Figure 1. Galvanostatic charge-discharge profiles of a coin cell assembled with the TBA-MnV 13 prepared in Example Three during the second cycle (activation) of the charge-discharge process. 51 V nuclear magnetic resonance spectrum; Figure 24 Figure 2. Galvanostatic charge-discharge profiles of a coin cell assembled with the TBA-MnV 13 prepared in Example Three during the twelfth cycle (post-activation) of the charge-discharge process. 51 V nuclear magnetic resonance spectrum; combined Figure 23 no significant changes in chemical shifts or peak shapes were found, indicating that the underlying V-O coordination framework remains intact despite the repeated redox cycling, suggesting that despite the introduction of Zn 2+ , the structure of TBA-MnV 13 retains its chemical integrity and coordination environment over long-term operation.

[0102] Figure 25 Figure 3. Galvanostatic charge-discharge profiles of a coin cell assembled with the TBA-MnV 13 prepared in Example Three during the discharge phase of the charge-discharge process. 13 Zn 2p X-ray photoelectron spectrum of the TBA-MnV 13 cathode; indicating the intercalation of zinc ions into the cathode material during the discharge phase.

[0103] Figure 26 Figure 4. Galvanostatic charge-discharge profiles of a coin cell assembled with the TBA-MnV 13 prepared in Example Three during the charge phase of the charge-discharge process. 13 Zn 2p X-ray photoelectron spectrum of the TBA-MnV 13 cathode; indicating the deintercalation of zinc ions from the cathode material during the charge phase.

[0104] Figure 27 Figure 5. Cycle performance plot of a coin cell assembled with the MnV 13 prepared in Example Three cycled at a current density of 1.0 Ag -1 ; 1 is the coulombic efficiency curve, 2 is the specific discharge capacity curve; Figure 28 Figure 6. Galvanostatic charge-discharge profiles of a coin cell assembled with the TBA-MnV 13 prepared in Example Three cycled at a current density of 1.0 Ag-1 The cycling performance graphs after 2700 cycles at a given current density are shown. 1 is the coulombic efficiency curve, and 2 is the discharge specific capacity curve. Figure 27 By combining and comparing, it can be found that TBA-MnV 13 The positive electrode initially exhibited a capacity of 300.4 mAh g. -1 It has a high capacity and still maintains 258.7mAh g after 2700 cycles. -1 Meanwhile, the Coulomb efficiency is nearly 100%, whereas MnV 13 The positive electrode exhibited a significant capacity loss, with the specific capacity decreasing from the initial 173.5 mAh g⁻¹ after 2700 cycles. -1 Reduced to 19.7mAh g -1 The above can be explained as follows: the improvement in cycle performance and capacity is mainly attributed to the TBA coating, which improves the structural integrity and reduces structural degradation.

[0105] Figure 29 Example 3 uses TBA-MnV 13 and MnV 13 The prepared aqueous zinc-ion battery cathode was used to assemble a coin cell at 0.2 Ag. -1 The graph shows a 300-cycle test at a current density of 0.2 Ag; -1 At low current densities, TBA-MnV 13 The specific capacity after 300 cycles is 289.9 mAh g. -1 The capacity retention rate reached 80%. In comparison, MnV 13 The specific capacity of the positive electrode was only 93.1 mAh g after 300 cycles. -1 (Only 47% of the initial capacity), such improvement in cycle performance and capacity is mainly attributed to the coating of TBA, which improves the integrity of the cathode material structure and reduces structural degradation.

[0106] Figure 30 Example 3 uses TBA-MnV 13 A comparison of the energy density and power density of the coin cell assembled from the aqueous zinc-ion battery cathode with those of previously reported vanadium-based cathode materials; TBA-MnV 13 The button cell battery achieved an energy density and power density of 237Wh / kg. -1 and 4.6kW kg -1 As can be seen from the figure, this surpasses many reported vanadium-based cathode materials, and it can be considered that TBA-MnV... 13 It is a very promising cathode material for advanced aqueous zinc-ion batteries;

[0107] Figure 30VO2(B) material data reference: Ding, J.; Du, Z.; Gu, L.; Li, B.; Wang, L.; Wang, S.; Gong, Y.; Yang, S., Ultrafast Zn 2+ Intercalation and Deintercalation in VanadiumDioxide. Advanced Materials 2018, 30 (26) 1800762.

[0108] Figure 30 Mg x V2O5 x nH2O material data reference: Genovese, M.; Lian, K., Polyoxometalate modified inorganic-organic nanocomposite materials for energy storage applications: A review. Current Opinion in Solid State and Materials Science 2015, 19 (2), 126-137.

[0109] Figure 30 Na 0.33 V2O5 material data reference: He, P.; Zhang, G.; Liao, X.; Yan, M.; Xu, X.; An, Q.; Liu, J.; Mai, L., Sodium Ion Stabilized Vanadium Oxide Nanowire Cathode for High-Performance Zinc-Ion Batteries. Advanced Energy Materials 2018, 8 (10), 1702463.

[0110] Figure 30 Na2V6O 16 x 1.63H2O material data reference: Hu, P.; Zhu, T.; Wang, X.; Wei, X.; Yan, M.; Li, J.; Luo, W.; Yang, W.; Zhang, W.; Zhou, L.; Zhou, Z.; Mai, L., Highly Durable Na2V6O16·1.63H2O Nanowire Cathode for Aqueous Zinc-Ion Battery. Nano Letters 2018, 18 (3), 1758-1763.

[0111] Figure 30 Medium Zn 0.25 V2O5 material data reference: Kundu, D.; Adams, B. D.; Duffort, V.; Vajargah, S. H.; Nazar, L. F., A high-capacity and long-life aqueous rechargeable zinc battery using a metal oxide intercalation cathode. Nature Energy 2016, 1 (10), 16119.

[0112] Figure 30 Medium NaV3O8x1.5H2O material data reference: Wan, F.; Zhang, L.; Dai, X.; Wang, X.; Niu, Z.; Chen, J., Aqueous rechargeable zinc / sodium vanadate batteries with enhanced performance from simultaneous insertion of dual carriers. Nature Communications 2018, 9 (1), 1656.

[0113] Figure 30 Medium VOPO4 material data reference: Wan, F.; Zhang, Y.; Zhang, L.; Liu, D.; Wang, C.; Song, L.; Niu, Z.; Chen, J., Reversible Oxygen Redox Chemistry in Aqueous Zinc-Ion Batteries. Angewandte Chemie International Edition 2019, 58 (21), 7062-7067.

[0114] Figure 30 Bulk V2O5 material data reference: Zhou, J.; Shan, L.; Wu, Z.; Guo, X.; Fang, G.; Liang, S., Investigation of V2O5 as a low-cost rechargeable aqueous zinc ion battery cathode. Chemical Communications 2018, 54 (35), 4457-4460.

[0115] Figure 31 TBA-MnV was used for Example Three 13 Self-discharge test of the prepared water-based zinc-ion battery positive electrode assembled button cell left standing for 48 hours; Figure 32 MnV was used for Example Three 13 Self-discharge test figure of the prepared water-based zinc-ion battery positive electrode assembled button cell left standing for 48 hours; Figure 31 Compared with the comparative example, TBA-MnV 13 maintained 88.75% of its initial capacity after standing for 48 hours, outperforming MnV 13 which maintained 85.07% capacity under the same conditions 13 Furthermore, during the static self-discharge process, the battery based on TBA-MnV 13 dropped to 1.09V, these results indicate that TBA coating endows the material with significant structural and electrochemical stability.

Claims

1. A MnV 13 A method for preparing a positive electrode material for a cluster aqueous zinc ion battery coated based on tetrabutylammonium, characterized in that It is carried out according to the following steps: I. Dissolve MnV 13 in deionized water to obtain a MnV 13 solution; II. Dissolve tetrabutylammonium chloride in deionized water to obtain a tetrabutylammonium chloride solution; III. The MnV solution was slowly added to the stirring tetrabutylammonium chloride solution, and the mixed solution was then concentrated, washed by centrifugation, and dried to obtain a dry powder. 13 The solution was slowly added to the stirring tetrabutylammonium chloride solution, and the mixed solution was then concentrated, washed by centrifugation, and dried to obtain a dry powder. IV. The dry powder was calcined under argon atmosphere to obtain tetrabutylammonium-coated MnV 13 , i.e. tetrabutylammonium-coated MnV 13 based clustered aqueous zinc-ion battery cathode material The tetrabutylammonium-coated MnV 13 of the formula (NH4)2(C 16 H 36 N)5MnV 13 O 38 .

2. A MnV cluster based on tetrabutylammonium coating according to claim 1 13 The preparation method of the cluster aqueous zinc ion battery cathode material is characterized by comprising the following steps MnV as described in step one 13 The mass to volume ratio of the deionized water is 1 g : (20-30) mL.

3. A MnV cluster based on tetrabutylammonium coating according to claim 1 13 The preparation method of the cluster aqueous zinc ion battery cathode material is characterized by comprising the following steps The mass of tetrabutylammonium chloride to the volume of deionized water in step II is 1g:(50-60)mL.

4. A MnV cluster based on tetrabutylammonium coating according to claim 1 13 The preparation method of the cluster aqueous zinc ion battery cathode material is characterized by comprising the following steps MnV as described in step three 13 The volume ratio of the solution to the tetrabutylammonium chloride solution is 1 : (3-4).

5. A MnV cluster based on tetrabutylammonium coating according to claim 1 13 The preparation method of the cluster aqueous zinc ion battery cathode material is characterized by comprising the following steps In step three, the MnV solution was added at a rate of 1 mL / min to 2 mL / min at a speed of 500 rpm to 800 rpm. 13 The solution was slowly added to the stirring tetrabutylammonium chloride solution for 1 h to 2 h.

6. A MnV cluster based on tetrabutylammonium coating according to claim 1 13 The preparation method of the cluster aqueous zinc ion battery cathode material is characterized by comprising the following steps The concentrated mixed solution in step III is specifically concentrated by using a rotary evaporator under the conditions of a temperature of 50-60℃ and a rotation speed of 100-120rpm until the solvent is completely evaporated; the centrifugal washing in step III is specifically centrifugal washing for 5-10min at a rotation speed of 8000-10000rpm, and the centrifugal washing is repeated for ≥3 times.

7. A MnV cluster based on tetrabutylammonium coating according to claim 1 13 The preparation method of the cluster aqueous zinc ion battery cathode material is characterized by comprising the following steps The drying in step III is specifically vacuum drying for 12-16h at a temperature of 50-60℃.

8. A MnV cluster based on tetrabutylammonium coating according to claim 1 13 The preparation method of the cluster aqueous zinc ion battery cathode material is characterized by comprising the following steps In step IV, the temperature is raised to 200-250℃ at a temperature raising speed of 3-5℃ / min under an argon atmosphere, and then calcination is carried out under the conditions of an argon atmosphere and a temperature of 200-250℃ for 5-6h.

9. A MnV cluster based on tetrabutylammonium coating as claimed in claim 1 13 Application of the cluster aqueous zinc-ion battery cathode material, characterized in that It is used for preparing a positive electrode of a water-based zinc ion battery.

10. A MnV cluster based on tetrabutylammonium coating according to claim 9 13 Application of the cluster aqueous zinc-ion battery cathode material, characterized in that It is used for preparing a positive electrode of a water-based zinc ion battery, and the preparation is carried out according to the following steps: It is used for preparing a positive electrode of a water-based zinc ion battery, and the preparation is carried out according to the following steps: Tetrabutylammonium-coated MnV 13 , a conductive agent, a binder and N-methylpyrrolidone were mixed to obtain a slurry, which was coated on a current collector in an amount of 0.7 mg / cm 2 ~ 1.0 mg / cm 2 The slurry was coated on the current collector and finally dried to obtain a positive electrode for aqueous zinc ion batteries. The tetrabutylammonium-coated MnV 13 The mass of the conductive agent to the mass of the binder is 7:(1~2); the tetrabutylammonium-coated MnV 13 The mass of the conductive agent to the mass of the binder is 7:(1~1.5); the tetrabutylammonium-coated MnV 13 The mass of the conductive agent to the mass of the binder is 7:(1~1.5); the tetrabutylammonium-coated MnV

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