阅读说明：本技术 一种水系锌离子电池正极材料、其制备方法及应用 (Water-based zinc ion battery positive electrode material, and preparation method and application thereof ) 是由 孔昱林 陈亮 刘兆平 于 2021-08-24 设计创作，主要内容包括：本发明涉及水系锌离子电池技术领域,尤其涉及一种水系锌离子电池正极材料、其制备方法及应用。所述水系锌离子电池正极材料的制备方法,包括：A)在加热的条件下,将铝盐溶液、铁氰化物溶液与水搅拌混合；B)所述搅拌混合完成后,继续反应,得到反应产物；C)将所述反应产物进行水洗,干燥后,得到水系锌离子电池正极材料。以这种水系锌离子电池正极材料为活性物质的正极能够稳定参与电极反应,不发生溶解现象,随着材料活化,容量随之增大,具有很大的应用潜力,由这种水系锌离子电池正极材料制得的电池的放电容量和循环性能均较优,是一种较为理想的正极材料。(The invention relates to the technical field of water-system zinc ion batteries, in particular to a water-system zinc ion battery positive electrode material, and a preparation method and application thereof. The preparation method of the anode material of the water-based zinc ion battery comprises the following steps: A) under the condition of heating, stirring and mixing an aluminum salt solution and a ferricyanide solution with water; B) after the stirring and mixing are finished, continuing the reaction to obtain a reaction product; C) and washing the reaction product with water, and drying to obtain the anode material of the water-based zinc ion battery. The anode taking the anode material of the water system zinc ion battery as an active substance can stably participate in electrode reaction without dissolution, the capacity is increased along with the activation of the material, and the anode has great application potential.)

1. A preparation method of a water system zinc ion battery positive electrode material comprises the following steps:

A) under the condition of heating, stirring and mixing an aluminum salt solution and a ferricyanide solution with water;

B) after the stirring and mixing are finished, continuing the reaction to obtain a reaction product;

C) and washing the reaction product with water, and drying to obtain the anode material of the water-based zinc ion battery.

2. The production method according to claim 1, wherein the aluminum salt solution includes at least one of an aluminum nitrate solution, an aluminum sulfate solution, and an aluminum acetate solution;

the concentration of the aluminum salt solution is 0.01-0.5 mol/L.

3. The production method according to claim 1, wherein the ferricyanide solution includes at least one of a potassium ferricyanide solution, a potassium ferrocyanide solution, a sodium ferricyanide solution, and a sodium ferrocyanide solution;

the concentration of the ferricyanide solution is 0.01-0.5 mol/L.

4. The method according to claim 1, wherein in step A), the molar ratio of aluminum ions in the aluminum salt solution to ferricyanide ions in the ferricyanide solution is 1 to 4: 1-3;

the volume of the aluminum salt solution and the volume of the ferricyanide solution are the same.

5. The method according to claim 1, wherein the step a) of mixing the aluminum salt solution and the ferricyanide solution with water under stirring comprises:

adding an aluminum salt solution and a ferricyanide solution to the stirred water at the same flow rate, respectively;

the flow rate is 10-100 mL/h.

6. The method according to claim 1, wherein the heating temperature in step A) is 60 to 100 ℃.

7. The preparation method according to claim 1, wherein in the step B), the temperature for continuous reaction is 60-100 ℃ and the time is 1-2 h;

the reaction also comprises the following steps: and (5) standing.

8. The method according to claim 1, wherein the step C) further comprises filtration before washing the reaction product with water;

the drying temperature is 80-100 ℃, and the drying time is 8-12 h.

9. The aqueous zinc ion battery positive electrode material prepared by the preparation method according to any one of claims 1 to 8.

10. An aqueous zinc-ion battery comprising a positive electrode, a negative electrode, a separator and an electrolyte, wherein the positive electrode comprises the positive electrode material for an aqueous zinc-ion battery according to claim 9.

Technical Field

The invention relates to the technical field of water-system zinc ion batteries, in particular to a water-system zinc ion battery positive electrode material, and a preparation method and application thereof.

Background

Energy and environment are two important problems that must be coordinated in the human society today, along with the unavailabilityThe exhaustion of renewable resources and the gradual deterioration of the environment make the development of new energy resources a global trend. The water-based battery has attracted much attention of researchers due to its advantages of environmental protection, low price, high energy density, and the like. The zinc has the advantages of low equilibrium voltage, high overpotential of hydrogen reaction, abundant resources, easy treatment and the like, so the water system Zinc Ion Batteries (ZIBs) with low price, environmental friendliness and high power become an ideal green battery system. However, the development of the water-based ZIBs is mostly limited by cathode materials, and problems such as cathode dissolution and capacity fading are easily caused in the battery cycling process, thereby severely restricting the development and commercialization of the water-based ZIBs. At present, the cathode materials commonly used by the water system ZIBs mainly comprise the following materials: 1. a manganese-based material; the manganese-based material mainly adopts MnO with various crystal structures₂As cathode materials for aqueous ZIBs, e.g. alpha-MnO₂、β-MnO₂And the like. 2. A vanadium-based material; the vanadium-based material mainly adopts vanadium oxide with a large channel skeleton as a cathode material of the water system ZIBs, such as vanadium dioxide (VO) with a tunnel skeleton₂) Vanadium pentoxide (V) of single-layer structure₂O₅) And the like. 3. A prussian blue analog; for example, zinc ferricyanide (ZnHCF) and copper ferricyanide (CuHCF) have been used as cathode materials for aqueous ZIBs. The Prussian blue analogue has a three-dimensional open framework, can be used for rapidly transmitting ions, has a large ion embedding site, is commonly used as a cathode material of a water-based zinc ion battery, has high output voltage and theoretical specific capacity, and therefore has received extensive attention of researchers.

However, existing aqueous ZIBs cathode materials suffer from the following disadvantages: 1. capacity is attenuated, various ions which are soluble in water system electrolyte can be generated by the manganese-based cathode material and the vanadium-based cathode material in the circulating process, so that the manganese-based cathode material and the vanadium-based cathode material are dissolved in a weak acidic zinc sulfate solution and a zinc trifluoromethanesulfonate solution, and the capacity is directly reduced due to the fact that the cathode material is dissolved due to the fact that active materials are lost. In addition, the iron element contained in the general prussian blue material is unstable in a reduced state and is easy to generate a side reaction with an electrolyte, so that the active material is decomposed, and the capacity is rapidly reduced. 2. The cost is high because vanadium is used as a rare metal; the Prussian blue material is generally synthesized based on transition metal salt, and when the transition metal is cobalt, nickel and other metal elements, the Prussian blue material has higher manufacturing cost. Therefore, how to prepare cheap water-based ZIBs cathode materials and have good cycling stability and capacity becomes a current research hotspot.

Chinese patent 201710217961.1 discloses a Prussian blue type sodium ion battery cathode material substituted by transition metal elements in a gradient manner and a preparation method thereof, wherein the preparation method needs to be carried out under the condition of protective gases such as argon or nitrogen, the preparation steps are complicated, and the preparation cost is high. Chinese patent 201910137100.1 discloses a Prussian blue analogue, a preparation method thereof, a cathode material and application thereof, wherein water is mainly used as a solvent, and Prussian blue analogue K with uniform grain size and good circulation stability is prepared by a coprecipitation method₂Zn₃[Fe(CN)₆]₂However, the cycling stability of such materials is still to be improved. Chinese patent CN201910256173.2 discloses a transition metal element co-doped Prussian blue analogue, a preparation method and application thereof, wherein the transition metal element co-doped Prussian blue analogue is a cubic Prussian blue-like material, and is a compound obtained by substituting transition metal elements cobalt and nickel for iron ions in iron-nitrogen octahedron in hexacyano complex crystal lattice according to a certain proportion, and the chemical formula is Na₂Ni_xCo_1-xFe(CN)₆In the disclosed preparation method, cobalt salt and nickel salt with higher price are needed, and a complexing agent is needed to be added in the preparation process, so that the preparation steps are complicated, and the preparation cost is higher. Chinese patent CN201711090633.6 discloses a Prussian blue electrode material and preparation and application thereof, wherein a layer of compact nickel hexacyanoferrate nano-particles is coated on the surface of the Prussian blue electrode material by a two-step coprecipitation method, and the compact nickel hexacyanoferrate nano-particles are used as a water system potassium ion battery anode material, so that the preparation steps are complicated, and the preparation cost is high.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide an aqueous zinc-ion battery positive electrode material, a preparation method and an application thereof, wherein the aqueous zinc-ion battery prepared from the aqueous zinc-ion battery positive electrode material has excellent electrochemical performance.

The invention provides a preparation method of a water system zinc ion battery anode material, which comprises the following steps:

A) under the condition of heating, stirring and mixing an aluminum salt solution and a ferricyanide solution with water;

B) after the stirring and mixing are finished, continuing the reaction to obtain a reaction product;

C) and washing the reaction product with water, and drying to obtain the anode material of the water-based zinc ion battery.

Preferably, the aluminum salt solution includes at least one of an aluminum nitrate solution, an aluminum sulfate solution, and an aluminum acetate solution;

the concentration of the aluminum salt solution is 0.01-0.5 mol/L.

Preferably, the ferricyanide solution includes at least one of a potassium ferricyanide solution, a potassium ferrocyanide solution, a sodium ferricyanide solution, and a sodium ferrocyanide solution;

the concentration of the ferricyanide solution is 0.01-0.5 mol/L.

Preferably, in the step a), the molar ratio of aluminum ions in the aluminum salt solution to ferricyanide ions in the ferricyanide solution is 1-4: 1-3;

the volume of the aluminum salt solution and the volume of the ferricyanide solution are the same.

Preferably, in the step a), the mixing the aluminum salt solution and the ferricyanide solution with water under stirring comprises:

adding an aluminum salt solution and a ferricyanide solution to the stirred water at the same flow rate, respectively;

the flow rate is 10-100 mL/h.

Preferably, in the step A), the heating temperature is 60-100 ℃.

Preferably, in the step B), the temperature for continuous reaction is 60-100 ℃ and the time is 1-2 h;

the reaction also comprises the following steps: and (5) standing.

Preferably, step C) further comprises filtering before washing the reaction product with water;

the drying temperature is 80-100 ℃, and the drying time is 8-12 h.

The invention also provides the water system zinc ion battery anode material prepared by the preparation method.

The invention also provides a water-based zinc ion battery, which comprises a positive electrode, a negative electrode, a diaphragm and electrolyte, and is characterized in that the positive electrode comprises the positive electrode material of the water-based zinc ion battery.

The source of the above-mentioned raw materials is not particularly limited, and the raw materials may be generally commercially available.

The invention provides a preparation method of a water system zinc ion battery anode material, which comprises the following steps: A) under the condition of heating, stirring and mixing an aluminum salt solution and a ferricyanide solution with water; B) after the stirring and mixing are finished, continuing the reaction to obtain a reaction product; C) and washing the reaction product with water, and drying to obtain the anode material of the water-based zinc ion battery. The anode material of the water system zinc ion battery prepared by the invention has low preparation cost, the anode taking the water system zinc ion battery anode material as an active substance can stably participate in electrode reaction without dissolution, along with material activation, a material frame structure is opened in the process of charge-discharge reaction, more and more zinc ions can be embedded, the capacity is increased along with the increase of the capacity, the water system zinc ion battery anode material has great application potential, the problems of easy anode dissolution, rapid capacity attenuation and high cost when the existing material is used as the water system zinc ion battery anode material are effectively solved, and the battery prepared by the water system zinc ion battery anode material has excellent discharge capacity and cycle performance, and is an ideal anode material.

Drawings

Fig. 1 is an SEM image of the cathode material of the aqueous zinc-ion battery according to example 1 of the present invention at 5k magnification;

fig. 2 is an SEM image of the water-based zinc-ion battery positive electrode material of example 1 of the present invention at 50k magnification;

FIG. 3 is a cyclic voltammogram of a three-electrode system of an aqueous zinc-ion battery according to example 3 of the present invention;

fig. 4 is a charge-discharge voltage-specific capacity curve diagram of the aqueous zinc ion button cell of example 3 of the present invention;

fig. 5 is a cyclic voltammogram of a three-electrode system of an aqueous zinc-ion battery of comparative example 2 of the invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a preparation method of a water system zinc ion battery anode material, which comprises the following steps:

A) under the condition of heating, stirring and mixing an aluminum salt solution and a ferricyanide solution with water;

B) after the stirring and mixing are finished, continuing the reaction to obtain a reaction product;

C) and washing the reaction product with water, and drying to obtain the anode material of the water-based zinc ion battery.

The invention firstly mixes the aluminum salt solution, the ferricyanide solution and the water under the condition of heating.

In some embodiments of the present invention, the heating temperature is 60 to 100 ℃. In certain embodiments of the invention, the heating is by oil bath heating.

In certain embodiments of the present invention, the aluminum salt solution comprises at least one of an aluminum nitrate solution, an aluminum sulfate solution, and an aluminum acetate solution. In certain embodiments of the present invention, the concentration of the aluminum salt solution is 0.01 to 0.5 mol/L. In certain embodiments, the concentration of the aluminum salt solution is 0.24mol/L or 0.06 mol/L.

In certain embodiments of the present invention, the ferricyanide solution comprises at least one of a potassium ferricyanide solution, a potassium ferrocyanide solution, a sodium ferricyanide solution, and a sodium ferrocyanide solution. In certain embodiments of the present invention, the concentration of the ferricyanide solution is 0.01 to 0.5 mol/L. In certain embodiments, the concentration of the ferricyanide solution is 0.12 mol/L.

In certain embodiments of the present invention, the molar ratio of aluminum ions in the aluminum salt solution to ferricyanide ions in the ferricyanide solution is 1-4: 1 to 3. In certain embodiments, the molar ratio of aluminum ions in the aluminum salt solution to ferricyanide ions in the ferricyanide solution is 2: 1 or 1: 1.

in certain embodiments of the present invention, the volume of the aluminum salt solution and the ferricyanide solution is the same.

In certain embodiments of the present invention, the mixing the aluminum salt solution, the ferricyanide solution, and the water with stirring comprises:

the aluminum salt solution and the ferricyanide solution were added to the stirred water at the same flow rates, respectively.

In some embodiments of the present invention, the flow rate is 10 to 100 mL/h. In certain embodiments, the flow rate is 33.6mL/h or 60 mL/h.

In the present invention, the water is a reaction medium of an aluminum salt and ferricyanide. In some embodiments of the present invention, the amount of the water is 50 to 100 mL. In certain embodiments, the amount of water is 100 mL.

In some embodiments of the invention, the stirring is vigorous stirring, and the rotation speed of the stirring is 500-1000 rpm. In certain embodiments, the rotational speed of the agitation is 600 rpm.

In some embodiments of the present invention, the temperature of the stirring and mixing is 60 to 100 ℃. In certain embodiments, the temperature of the stirring and mixing is 80 ℃.

And after the stirring and mixing are finished, continuing the reaction to obtain a reaction product.

In some embodiments of the present invention, the temperature for the continuous reaction is 60-100 ℃ and the time is 1-2 hours. In certain embodiments, the time for continuing the reaction is 2h or 1.5 h.

In some embodiments of the present invention, the continuous reaction is performed under stirring, wherein the stirring is vigorous stirring, and the rotation speed of the stirring is 500-1000 rpm.

In certain embodiments of the invention, the agitated mixing and the continuing reaction are both conducted in a reactor.

In certain embodiments of the invention, neither the agitated mixing nor the continued reaction need be conducted under protective gas conditions.

In certain embodiments of the invention, after continuing the reaction, still standing is included. In certain embodiments of the invention, the time of standing is 12 hours.

And after a reaction product is obtained, washing the reaction product with water, and drying to obtain the water system zinc ion battery anode material.

In certain embodiments of the present invention, filtration is included before the reaction product is subjected to water washing. The filtration method may be suction filtration.

And after the filtration is finished, washing the filtered precipitate with water, and drying to obtain the anode material of the water-based zinc ion battery.

In certain embodiments of the present invention, the water wash employs deionized water.

In some embodiments of the invention, the drying temperature is 80-100 ℃ and the drying time is 8-12 h. In certain embodiments, the temperature of the drying is 80 ℃. In certain embodiments, the drying time is 12 hours or 10 hours.

In certain embodiments of the invention, the drying is performed in a drying oven.

The source of the above-mentioned raw materials is not particularly limited in the present invention, and may be generally commercially available.

The preparation method of the anode material of the water-based zinc ion battery provided by the invention is a one-step coprecipitation method. In certain embodiments of the present invention, the aqueous zinc-ion battery positive electrode material is prepared without using a complexing agent.

The invention also provides the water system zinc ion battery anode material prepared by the preparation method.

The water-based zinc ion battery anode material provided by the invention is Prussian blue analogue aluminum ferrocyanide (AlHCF), and can solve the problem of cathode dissolution of the water-based zinc ion battery.

In some embodiments of the invention, the water-based zinc-ion battery positive electrode material is nanoparticles with a particle size of 100-300 nm, and agglomeration exists among the nanoparticles. The anode material of the water-based zinc ion battery has a large specific surface area.

The invention also provides a water-based zinc ion battery, which comprises a positive electrode, a negative electrode, a diaphragm and electrolyte, wherein the positive electrode comprises the positive electrode material of the water-based zinc ion battery.

In some embodiments of the invention, the negative electrode is Zn foil, Zn sheet, or Zn powder.

Specifically, the Zn foil or Zn sheet can be cut into a wafer with a suitable diameter to be used as a negative electrode sheet; or uniformly stirring the raw material a in a 1-methyl-2-pyrrolidone solvent, then uniformly coating the slurry on a current collector (a stainless steel grid, a molybdenum net, a nickel net or an aluminum foil), and drying at 60-80 ℃ for 8-12 h to obtain a negative plate;

the raw material a comprises 75-80 wt% of Zn powder, 10-15 wt% of conductive carbon black and 10-15 wt% of polyvinylidene fluoride.

In certain embodiments of the present invention, the method of preparing the positive electrode comprises:

uniformly stirring the raw material b in a 1-methyl-2-pyrrolidone solvent, then uniformly coating the slurry on a current collector (a stainless steel grid, a molybdenum net, a nickel net or an aluminum foil), and drying at 60-80 ℃ for 8-12 h to obtain a positive plate;

the raw material b comprises 75-80 wt% of active materials, 10-15 wt% of conductive carbon black and 10-15 wt% of polyvinylidene fluoride. The active material is the above-mentioned aqueous zinc ion battery positive electrode material.

In certain embodiments of the present invention, the active material content of the feedstock b is 75 wt%. In certain embodiments of the present invention, the conductive carbon black content of the feedstock b is 15 wt%. In certain embodiments of the present invention, the polyvinylidene fluoride content of the raw material b is 10 wt%.

In certain embodiments of the present invention, the electrolyte is a zinc salt electrolyte. In particular, zinc sulfate solution (Z) can be usednSO₄) Zinc trifluoromethanesulfonate solution (Zn (CF)₃SO₃)₂) Zinc nitrate solution (Zn (NO)₃)₂) Or zinc chloride solution (ZnCl)₂). In some embodiments, the zinc salt electrolyte is a saturated zinc salt electrolyte, or the concentration of the zinc salt electrolyte is 0.5-3 mol/L. In certain embodiments, the concentration of the zinc salt electrolyte is 3 mol/L. The invention further adopts high-concentration electrolyte to inhibit the dissolution of the anode, improve the activation effect and prolong the cycle life of the electrode.

In certain embodiments of the present invention, the membrane is a 1823-GF/D glass fiber battery membrane.

In certain embodiments of the present invention, the method of making the aqueous zinc-ion battery comprises the steps of:

placing the cathode shell flatly, placing a stainless steel gasket with the same diameter as the Zn cathode sheet, placing the Zn cathode sheet on the gasket, adding electrolyte, placing a layer of diaphragm, adding electrolyte, placing the anode sheet on the diaphragm paper, covering the stainless steel gasket and the elastic sheet, adding the electrolyte, covering the anode shell, placing the anode shell on a packaging machine, packaging the battery, and preparing the water system zinc ion button battery.

The invention has no special limit on the dosage of the electrolyte, and can wet the pole piece and the diaphragm.

The source of the above-mentioned raw materials is not particularly limited, and the raw materials may be generally commercially available.

The invention provides a preparation method of a water system zinc ion battery anode material, which comprises the following steps: A) under the condition of heating, stirring and mixing an aluminum salt solution and a ferricyanide solution with water; B) after the stirring and mixing are finished, continuing the reaction to obtain a reaction product; C) and washing the reaction product with water, and drying to obtain the anode material of the water-based zinc ion battery. The anode material of the water system zinc ion battery prepared by the invention has low preparation cost, the anode taking the water system zinc ion battery anode material as an active substance can stably participate in electrode reaction without dissolution, along with material activation, a material frame structure is opened in the process of charge-discharge reaction, more and more zinc ions can be embedded, the capacity is increased along with the material activation, the water system zinc ion battery anode material has great application potential, the problems of easy anode dissolution, rapid capacity attenuation and high cost when the existing material is used as the water system zinc ion battery anode material are effectively solved, and the water system zinc ion battery anode material is an ideal anode material. The battery prepared from the anode material of the water system zinc ion battery has excellent discharge capacity and cycle performance.

In order to further illustrate the present invention, the following will describe in detail the cathode material of the water-based zinc-ion battery, the preparation method and the application thereof with reference to the examples, but the scope of the present invention should not be construed as being limited thereto.

Example 1

1. 9.003g of aluminum nitrate nonahydrate (Al (NO) was added to each flask₃)₃·9H₂O) and 5.069g of potassium ferrocyanide trihydrate (K)₄Fe(CN)₆·3H₂O) was dissolved in 100mL of deionized water to prepare a 0.24mol/L solution of aluminum nitrate and a 0.12mol/L solution of potassium ferrocyanide. Wherein the molar ratio of the aluminum ions to the ferrous cyanide ions is 2: 1.

2. carrying out high-temperature coprecipitation reaction in a reactor: the aluminum nitrate solution and the potassium ferrocyanide solution were added dropwise (33.6mL/h) at the same flow rate to a round bottom flask (100 mL of water in the round bottom flask) using a peristaltic pump under an oil bath at 80 deg.C, and the whole process was carried out under vigorous stirring (600 rpm for stirring).

3. And after the aluminum nitrate solution and the potassium ferrocyanide solution are dropwise added, continuing to react for 2 hours, stopping heating and stirring after the reaction is finished, and standing the reactant for 12 hours.

4. And (3) carrying out suction filtration on the sediment at the bottom of the reactor, washing with deionized water for 3 times, and then putting into a drying oven at 80 ℃ for drying for 12h to obtain the final product, namely the water-based zinc ion battery positive electrode material (AlHCF).

In this example, SEM scanning analysis was performed on the obtained cathode material of the aqueous zinc-ion battery, and as a result, fig. 1 and 2 show that fig. 1 is an SEM image of the cathode material of the aqueous zinc-ion battery of example 1 of the present invention at a magnification of 5 k. Fig. 2 is an SEM image of the water-based zinc-ion battery positive electrode material of example 1 of the present invention at 50k magnification. As can be seen from FIGS. 1 and 2, the micro-morphology of the anode material of the water-based zinc-ion battery is a uniform spherical structure, the diameter of the anode material is 100-300 nm, the anode material has a large specific surface area, and the anode material is agglomerated to a certain extent.

Example 2

1. 3.257g of aluminum sulfate octadecahydrate (Al) are added separately₂(SO₄)₃·18H₂O) and 5.809g of sodium ferrocyanide decahydrate (Na)₄Fe(CN)₆·10H₂O) was dissolved in 100mL of deionized water to prepare a 0.06mol/L aluminum sulfate solution and a 0.12mol/L sodium ferrocyanide solution. Wherein the molar ratio of the aluminum ions to the ferrous cyanide ions is 1: 1.

2. carrying out high-temperature coprecipitation reaction in a reactor: the aluminum sulfate solution and the sodium ferrocyanide solution were added dropwise (60mL/h) to the round-bottom flask (the volume of water in the round-bottom flask was 100mL) at the same flow rate using a peristaltic pump under an oil bath at 80 ℃ and the whole process was carried out under vigorous stirring (the rotation speed of the stirring was 600 rpm).

3. And after the aluminum sulfate solution and the sodium ferrocyanide solution are dropwise added, continuously reacting for 1.5 hours, stopping heating and stirring after the reaction is finished, and standing the reactant for 12 hours.

4. And (3) carrying out suction filtration on the sediment at the bottom of the reactor, washing with deionized water for 3 times, and then putting into a drying oven at 80 ℃ for drying for 10h to obtain the final product, namely the water-based zinc ion battery positive electrode material (AlHCF).

Example 3

Preparation of an aqueous zinc ion battery:

uniformly stirring 75 wt% of active material, 15 wt% of conductive carbon black and 10 wt% of polyvinylidene fluoride in a 1-methyl-2-pyrrolidone solvent, then uniformly coating the slurry on a current collector aluminum foil, and drying at 70 ℃ for 10 hours to obtain a positive plate; the active material was the aqueous zinc-ion battery positive electrode material prepared in example 1.

Zn foil is taken as a negative plate, zinc sulfate solution with the concentration of 3mol/L is taken as electrolyte, and 1823-GF/D glass fiber battery diaphragm (brand: whatman) is taken as a diaphragm.

Placing a cathode shell flatly, putting a stainless steel gasket with the same diameter as the cathode piece, then placing a Zn cathode piece on the gasket, adding electrolyte (only soaking a pole piece and a diaphragm), then putting a layer of diaphragm, adding electrolyte (only soaking the pole piece and the diaphragm), putting the anode piece on diaphragm paper, covering the stainless steel gasket and an elastic sheet, adding electrolyte (only soaking the pole piece and the diaphragm), finally covering the anode shell, putting the battery on a packaging machine for packaging, and preparing the aqueous zinc-ion button battery.

In a three-electrode system, the positive plate in example 3 is used as a working electrode, a platinum plate is used as a counter electrode, Al/AgCl is used as a reference electrode, a cyclic voltammetry test is performed on a solatron analytical multifunctional electrochemical workstation (model 1470E), the test voltage interval is 0-1.3V, and the scanning rate is 2mV/s, so that a cyclic voltammogram is obtained. Fig. 3 is a cyclic voltammogram of a three-electrode system of an aqueous zinc-ion battery according to example 3 of the present invention. As can be seen from FIG. 3, the peak area of the cyclic voltammogram gradually increases with the increase of the cycle number, which indicates that the capacity of the working electrode continuously increases with the cycle number, and the upper peak and the lower peak are symmetrical in shape, indicating that the electrochemical reaction is highly reversible.

In a three-electrode system, the positive plate of example 3 was used as a working electrode, a platinum plate as a counter electrode, and Al/AgCl as a reference electrode, and a constant-current charge-discharge test was performed on a solartron analytical multifunctional electrochemical workstation (model 1470E), wherein the charge-discharge voltage interval was-0.2 to 1V, and the charge-discharge current density was 60mA g/g^-1And obtaining a charge-discharge voltage-specific capacity curve. Fig. 4 is a charge-discharge voltage-specific capacity curve diagram of the aqueous zinc ion battery of example 3 of the present invention. As can be seen from FIG. 4, the specific discharge capacity of the battery at the 1 st cycle was 24.90mAh g^-1After the 50 th cycle, the battery capacity reaches 72.02mAh g^-1The result shows that the battery capacity is activated in the circulation process, the battery capacity reaches 3 times of the initial capacity after 50 times of circulation, the capacity retention rate is higher than 90% after the subsequent 50 times of circulation, and the material shows good discharge capacity and circulation performance.

Example 4

An aqueous zinc ion battery was prepared according to the method of example 3, which differs from example 3 in that: the active material is the anode material of the water-based zinc ion battery prepared in example 2

The water system zinc ion battery of the embodiment 4 is subjected to constant current charge and discharge test on a solartron analytical multifunctional electrochemical workstation (model 1470E), the charge and discharge voltage interval is-0.2-1V, and the charge and discharge current density is 60mA g^-1. The experimental result shows that the specific discharge capacity of the battery at the 1 st cycle is 23.20 mAh.g^-1After the 50 th cycle, the battery capacity reaches 70.15mAh g^-1The result shows that the battery capacity is activated in the circulation process, the battery capacity reaches 3 times of the initial capacity after 50 times of circulation, the capacity retention rate is higher than 90% after the subsequent 50 times of circulation, and the material shows good discharge capacity and circulation performance.

Comparative example 1

1. Respectively adding 6.901g of zinc sulfate (ZnSO)₄) And 5.068g of potassium ferrocyanide trihydrate (K)₄Fe(CN)₆·3H₂O) was dissolved in 100mL of deionized water to prepare a 0.24mol/L zinc sulfate solution and a 0.12mol/L potassium ferricyanide solution. Wherein the molar ratio of zinc ions to ferricyanide ions is 2: 1.

2. carrying out high-temperature coprecipitation reaction in a reactor: the zinc sulphate solution and potassium ferricyanide solution were added dropwise (33.6mL/h) at the same flow rate to a round bottom flask (100 mL of water in the round bottom flask) using a peristaltic pump under an oil bath at 60 c, the whole process being carried out under vigorous stirring (rotation speed of stirring 600 rpm).

3. And after the zinc sulfate solution and the potassium ferricyanide solution are dropwise added, continuously reacting for 2 hours, stopping heating and stirring after the reaction is finished, and standing the reactant for 12 hours.

4. And (3) carrying out suction filtration on the sediment at the bottom of the reactor, washing with deionized water for 3 times, and then putting into a drying oven at 80 ℃ for drying for 12h to obtain the final product, namely the water-based zinc ion battery positive electrode material (ZnHCF).

Comparative example 2

Uniformly stirring 75 wt% of active material, 15 wt% of conductive carbon black and 10 wt% of polyvinylidene fluoride in a 1-methyl-2-pyrrolidone solvent, then uniformly coating the slurry on a current collector stainless steel net, and drying at 70 ℃ for 10 hours to obtain a positive plate; the active material was the aqueous zinc-ion battery positive electrode material prepared in comparative example 1.

In a three-electrode system, the positive plate is taken as a working electrode, the platinum plate is taken as a counter electrode, Al/AgCl is taken as a reference electrode, and 3mol/L ZnSO₄The solution is used as electrolyte, and a test is carried out on a solartron analytical multifunctional electrochemical workstation (model 1470E), the test voltage interval is-0.2-1.2V, the scanning speed is 2mV/s, and a cyclic voltammogram is obtained. Fig. 5 is a cyclic voltammogram of a three-electrode system of an aqueous zinc-ion battery of comparative example 2 of the invention. As can be seen from fig. 5, after the first cycle, the capacity of the ZnHCF positive electrode significantly decays, and as the cycle number increases, the peak area of the cyclic voltammogram gradually decreases, indicating that the capacity of the working electrode continuously decays with the cycle number.

In a three-electrode system, the positive plate is taken as a working electrode, the platinum plate is taken as a counter electrode, Al/AgCl is taken as a reference electrode, and 3mol/L ZnSO₄The solution is electrolyte, constant current charging and discharging tests are carried out on a solartron analytical multifunctional electrochemical workstation (model 1470E), the charging and discharging voltage interval is-0.2-1V, and the charging and discharging current density is 60mA g^-1. The experimental result shows that the specific discharge capacity of the battery at the 1 st cycle is 66.42mAh g^-1The battery capacity after the 50 th cycle was 54.46mAh · g^-1Indicating a gradual decay in battery capacity during cycling, and after 50 subsequent cycles, a capacity decay of 48.49mAh g^-1The capacity retention rate was 73.0%.

The examples and the comparative examples show that compared with the conventional Prussian blue material, the AlHCF provided by the invention has a unique activation process when being used as a positive electrode material of an aqueous zinc ion battery.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.