A high-voltage aqueous zinc-based dual-ion battery based on potassium-containing prussian blue positive electrode material and a preparation method thereof

Abstract

This invention discloses a high-voltage aqueous zinc-based dual-ion battery based on Prussian blue cathode material, comprising a positive electrode, a negative electrode, a separator, and two aqueous electrolytes; the positive electrode comprises a positive electrode active material, acetylene black, and polytetrafluoroethylene; the positive electrode active material is a potassium-containing Prussian blue material. This aqueous zinc-based dual-ion battery achieves a voltage as high as 2.6V at 0.2A g. ‑1 At current density, the energy density is approximately 120 Wh / kg. ‑1 Furthermore, it exhibits good cycle stability. In addition, the one-step synthesis method for Prussian blue cathode material is simple, highly controllable, and uses inexpensive raw materials, making it suitable for large-scale production. The high-voltage aqueous zinc-based dual-ion battery of this invention shows promising application prospects in energy storage power stations, transportation, and defense technology.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochemical energy storage, and relates to a high-voltage aqueous zinc-based dual-ion battery based on a potassium-containing Prussian blue positive electrode material and a preparation method thereof. TECHNICAL BACKGROUND

[0002] Lithium ion batteries have been widely used in the power grid field due to high energy density, but their low safety and high cost limit further large-scale application. The aqueous zinc ion battery has attracted wide attention due to high safety, environmental friendliness, low cost, simple battery assembly and other advantages, and is expected to be applied to large-scale energy storage field.

[0003] During the charging and discharging process of the aqueous zinc ion battery, repeated Zn 2+ or H + / Zn 2+ co-insertion will cause most of the positive electrode materials to dissolve and be unstable in structure, and the battery has a short cycle life. In addition, Zn 2+ has a large charge density, and there is a strong electrostatic interaction between Zn 2+ and the crystal structure of the positive electrode material, resulting in slow insertion kinetics of Zn + and poor rate performance of the battery. To solve these problems, researchers design monovalent cations (Li + , Na + , K x ) with fast migration speed to replace the slow migration speed of hydrated zinc ions to insert into the positive electrode, and the zinc negative electrode can be deposited / peeled during charging, thereby forming a unique aqueous zinc-based dual-ion battery. For the study of the aqueous zinc-based dual-ion battery, low energy density and poor cycle stability are the main bottlenecks faced by researchers, and the electrolyte decoupling strategy (i.e. the positive and negative electrodes of the aqueous battery are placed in different electrolytes) can expand the potential window, thereby increasing the energy density of the aqueous battery, so screening suitable electrode materials to assemble high-performance aqueous zinc-based dual-ion batteries is of great concern.

[0004] At present, the electrode materials for the aqueous zinc-based dual-ion battery mainly include lithium manganate, lithium iron phosphate, Prussian blue and analogues thereof. The first two have high cost and are not suitable for large-scale application of the aqueous zinc-based dual-ion battery.

[0005] Prussian blue and analogues thereof are a class of metal cyanide with hexagonal perovskite type, and the molecular formula can be expressed as P x M a M b (CN)6, wherein P x represents an alkali metal ion (such as Li + , Na + , K + , etc.), M a represents a transition metal connected to nitrogen, and M bM represents a transition metal connected to carbon a and M b Generally, it is one of Fe, Co, Ni, etc., when M a and M b are both Fe, it is Prussian blue. Prussian blue has an ideal three-dimensional framework structure, can realize the rapid embedding and extraction of ions, and is non-toxic, low in cost, safe and easy to prepare, and is therefore of concern to researchers as an electrode material. Therefore, constructing a high-performance aqueous zinc-based dual-ion battery based on Prussian blue electrode material is currently a hot research topic. SUMMARY

[0006] The present application aims at the key problems of low voltage and unsatisfactory cycle life of the aqueous zinc-based dual-ion battery, and provides a high-voltage aqueous zinc-based dual-ion battery based on potassium-containing Prussian blue positive electrode material and a preparation method thereof.

[0007] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0008] A high-voltage aqueous zinc-based dual-ion battery based on Prussian blue positive electrode material, comprising a positive electrode, a negative electrode, a separator and two kinds of aqueous electrolyte; the positive electrode comprises a positive electrode active material, acetylene black and polytetrafluoroethylene; the positive electrode active material is a potassium-containing Prussian blue material.

[0009] Further, the negative electrode is zinc metal.

[0010] Further, the separator is a cation permeable membrane.

[0011] Further, the two kinds of aqueous electrolyte are alkaline electrolyte solution and neutral electrolyte solution; the alkaline electrolyte solution is potassium hydroxide solution, and the neutral electrolyte solution is potassium sulfate solution.

[0012] Further, the concentration of the alkaline electrolyte solution is 0.5-1 mol / L -1 .

[0013] Further, the concentration of the neutral electrolyte solution is 0.5-1 mol / L -1 .

[0014] The present application also provides a preparation method of a high-voltage aqueous zinc-based dual-ion battery based on Prussian blue positive electrode material, comprising the following steps:

[0015] (1) Preparation of potassium-containing Prussian blue positive electrode sheet

[0016] Take 2mmol potassium ferrocyanide dissolved in 100ml of deionized water, prepared solution, then respectively 10mmol potassium chloride, 5ml hydrochloric acid and 2g polyvinylpyrrolidone are added to the above solution;At 80℃, the water bath is reacted for 12 hours, then it is static for 12 hours, the sample is collected by centrifugation, and finally dried to obtain the potassium-containing prussian blue material;

[0017] The potassium-containing prussian blue material, acetylene black and polytetrafluoroethylene are mixed in a certain mass ratio, N-methylpyrrolidone is added to make them into a slurry, and repeated rolling is carried out to form a thin sheet, which is pressed on a sheared nickel mesh to form an electrode sheet, and then dried in a vacuum drying box for 24 hours to obtain a prussian blue positive electrode sheet;

[0018] (2) Preparation of zinc negative electrode sheet

[0019] The zinc foil is cut into a suitable size, then washed with dilute sulfuric acid and deionized water, and finally dried in a vacuum drying box at 80℃ for 24 hours at room temperature to obtain a negative electrode sheet;

[0020] (3) Assembly of aqueous dual-ion battery

[0021] Firstly, the cation permeable membrane is placed in the middle of the H-type electrolytic cell to separate the positive and negative parts;Then, the prussian blue positive electrode sheet prepared in step (1) and the negative electrode sheet prepared in step (2) are taken, and the mass ratio of the negative electrode sheet to the prussian blue positive electrode sheet is 1: (8-10). Finally, the prussian blue positive electrode sheet is soaked in a neutral electrolyte solution, and the negative electrode sheet is soaked in an alkaline electrolyte solution, to obtain an aqueous dual-ion battery.

[0022] Further, the molecular formula of the potassium-containing prussian blue material in step (1) is K2FeFe(CN)6.

[0023] Further, the morphology of the potassium-containing prussian blue material is spherical, and the particle size is 200-300 nanometers.

[0024] Further, the potassium-containing prussian blue material, acetylene black and polytetrafluoroethylene in step (1) are mixed in a mass ratio of 8:1:1.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] The present application relates to a kind of high-performance water-based zinc-based dual-ion battery prepared by using potassium-containing prussian blue as positive material, cation permeable membrane as diaphragm and zinc metal as negative material, the preparation process is simple, can be assembled into large-scale energy storage equipment, very suitable for fixed large-scale energy storage field.Compared with the water-based zinc-based dual-ion battery reported, potassium-containing prussian blue positive material uses potassium salt precursor one-step synthesis, easy to operate, potassium salt is cheap and potassium resource is abundant, suitable for large-scale production and application.At the same time, the application of two kinds of water-based electrolyte can effectively expand the potential window of capacitor, improve the energy density of supercapacitor.The voltage window of the water-based zinc-based dual-ion battery of the present application is as high as 2.6V, and the discharge voltage platform is about 2.2V, at 0.2A g -1 Current density, discharge specific capacity is as high as 118mAh g -1 , energy density is about 120Wh kg -1 , show higher discharge specific capacity, energy density and good charge-discharge cycle life.At present, more than 2.5V voltage water-based zinc-based dual-ion battery prepared by using potassium-containing prussian blue and zinc metal as positive and negative electrode has not been reported, the battery of the present application has good controllability, low cost, and has great application prospect in mobile communication, consumer electronics, transportation and national defense technology fields. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is the X-ray diffraction pattern (XRD pattern) of potassium-containing prussian blue positive material prepared in embodiment 1 of the present application.

[0028] Figure 2 It is the scanning electron microscope pattern (SEM pattern) of potassium-containing prussian blue positive material prepared in embodiment 1 of the present application.

[0029] Figure 3 It is the structure and composition diagram of water-based dual-ion battery in embodiment 1 of the present application.

[0030] Figure 4 It is the 0.2A g -1 Charge-discharge curve diagram of potassium-containing prussian blue positive material prepared in embodiment 1 of the present application.

[0031] Figure 5 It is the 0.2A g -1 Charge-discharge cycle performance diagram of potassium-containing prussian blue positive material prepared in embodiment 1 of the present application. DETAILED DESCRIPTION

[0032] The present application will be described in detail below by means of drawings and specific embodiments, but the protection scope of the present application is not limited. Unless otherwise specified, the experimental methods used in the present application are conventional methods, and experimental apparatus, materials and reagents used can be purchased from chemical companies.

[0033] Example 1

[0034] A method for preparing a high-voltage aqueous zinc-based dual-ion battery based on potassium-containing Prussian blue cathode material includes the following steps:

[0035] Synthesis of potassium-containing Prussian blue material: 2 mmol of potassium ferrocyanide was dissolved in 100 ml of deionized water. Then, 10 mmol of potassium chloride, 5 ml of hydrochloric acid and 2 g of polyvinylpyrrolidone were added to the above solution respectively. The reaction was carried out in a water bath at 80 °C for 12 hours, followed by standing for 12 hours. The sample was collected by centrifugation and finally dried to obtain Prussian blue nanomaterial. Figure 1 The XRD pattern of the synthesized Prussian blue sample shows that its characteristic peaks match the standard peaks very well, proving that the prepared sample has high phase purity. Figure 2 The SEM image of the synthesized Prussian blue sample shows that the Prussian blue has a regular spherical morphology with a particle size of 200-300 nanometers.

[0036] Preparation of potassium Prussian blue positive electrode sheet: Prussian blue, acetylene black and polytetrafluoroethylene are mixed in a mass ratio of 8:1:1. An appropriate amount of N-methylpyrrolidone is added to make the three into a slurry. The mixture is repeatedly rolled into a thin sheet and pressed onto a sheared nickel mesh to form an electrode sheet. Then, it is dried in a vacuum drying oven for 24 hours to obtain the potassium Prussian blue positive electrode sheet.

[0037] Preparation of negative electrode sheet: Commercial zinc foil is cut into appropriate sizes, then the zinc foil is cleaned with dilute sulfuric acid and deionized water, and finally vacuum dried at room temperature for 24 hours in a vacuum drying oven at 80°C to obtain the negative electrode sheet.

[0038] See Figure 3 Assemble an aqueous dual-ion battery: First, place a cation-permeable membrane in the middle of an H-type electrolytic cell, separating the positive and negative electrode sections. Then, take a Prussian blue positive electrode and a zinc negative electrode, with a zinc negative electrode to Prussian blue material mass ratio of 1:9. Finally, immerse the positive electrode in 0.5 mol / L... -1 The negative electrode sheet was immersed in a 1 mol L solution of neutral K2SO4 electrolyte. -1 Aqueous dual-ion batteries are obtained by using KOH alkaline electrolyte solution.

[0039] The invented aqueous zinc-based dual-ion battery has a voltage window as high as 2.6V (see...). Figure 4 The discharge plateau is approximately 2.2V; at 0.2A g -1 At current density ( Figure 4 The discharge specific capacity is as high as 118mAh g. -1 Energy density approximately 120Wh / kg -1 After 300 charge-discharge cycles (see...)Figure 5 ), which has a discharge specific capacity of 105mAh g -1 , with a capacity retention of up to 89%; exhibits high discharge specific capacity, high energy density and good charge-discharge cycle life.

[0040] Example 2

[0041] A preparation method of a high-voltage aqueous zinc-based dual-ion battery based on a potassium-containing Prussian blue positive electrode material, comprising the following steps:

[0042] Synthesis of potassium-containing Prussian blue material: 2mmol of potassium ferrocyanide is dissolved in 100ml of deionized water, and then 10mmol of potassium chloride, 5ml of hydrochloric acid and 2g of polyvinylpyrrolidone are added respectively into the above solution; the reaction is carried out in a water bath at 80℃ for 12 hours, and then the sample is collected by centrifugation and dried to obtain the Prussian blue nanomaterial.

[0043] Preparation of potassium-containing Prussian blue positive electrode sheet: Prussian blue, acetylene black and polytetrafluoroethylene are mixed in a mass ratio of 8:1:1, and an appropriate amount of N-methylpyrrolidone is added to make them into a slurry, which is repeatedly rolled into a thin sheet and pressed on a sheared nickel mesh to form an electrode sheet, which is then dried in a vacuum drying oven for 24 hours to obtain the potassium-containing Prussian blue positive electrode sheet.

[0044] Preparation of negative electrode sheet: Commercial zinc foil is cut into a suitable size, and then washed with dilute sulfuric acid and deionized water, and finally dried in a vacuum drying oven at 80℃ for 24 hours at room temperature to obtain the negative electrode sheet.

[0045] Assembly of aqueous dual-ion battery: First, the cation-permeable membrane is placed in the middle of the H-type electrolytic cell to separate the positive and negative parts. Then, the Prussian blue positive electrode sheet and the zinc negative electrode sheet are taken, and the mass ratio of the zinc negative electrode to the Prussian blue material is 1:9. Finally, the positive electrode sheet is soaked in a 1mol L -1 K2SO4 neutral electrolyte solution, and the negative electrode sheet is soaked in a 1mol L - 1 KOH alkaline electrolyte solution to obtain the aqueous dual-ion battery.

[0046] The voltage window of the invented aqueous zinc-based dual-ion battery is up to 2.6V, and the discharge platform is about 2.2V; at a current density of 0.2A g -1 , the discharge specific capacity is up to 126mAh g -1 , and the energy density is about 122Wh kg -1 ; after 300 charge-discharge cycles, the discharge specific capacity is 101mAh g -1It achieves a capacity retention rate of 80%, demonstrating high discharge specific capacity, high energy density, and good charge-discharge cycle life.

[0047] Example 3

[0048] A method for preparing a high-voltage aqueous zinc-based dual-ion battery based on potassium-containing Prussian blue cathode material includes the following steps:

[0049] Synthesis of potassium-containing Prussian blue material: 2 mmol of potassium ferrocyanide was dissolved in 100 ml of deionized water. Then, 10 mmol of potassium chloride, 5 ml of hydrochloric acid and 2 g of polyvinylpyrrolidone were added to the above solution respectively. The reaction was carried out in a water bath at 80 °C for 12 hours, followed by standing for 12 hours. The sample was collected by centrifugation and finally dried to obtain Prussian blue nanomaterial.

[0050] Preparation of potassium Prussian blue positive electrode sheet: Prussian blue, acetylene black and polytetrafluoroethylene are mixed in a mass ratio of 8:1:1. An appropriate amount of N-methylpyrrolidone is added to make the three into a slurry. The mixture is repeatedly rolled into a thin sheet and pressed onto a sheared nickel mesh to form an electrode sheet. Then, it is dried in a vacuum drying oven for 24 hours to obtain the potassium Prussian blue positive electrode sheet.

[0051] Preparation of negative electrode sheet: Commercial zinc foil is cut into appropriate sizes, then the zinc foil is cleaned with dilute sulfuric acid and deionized water, and finally vacuum dried at room temperature for 24 hours in a vacuum drying oven at 80°C to obtain the negative electrode sheet.

[0052] Assembling an aqueous dual-ion battery: First, place the cation-permeable membrane in the middle of an H-type electrolytic cell, separating the positive and negative electrode sections. Then, take a Prussian blue positive electrode and a zinc negative electrode, with a zinc negative electrode to Prussian blue material mass ratio of 1:10. Finally, immerse the positive electrode in 0.5 mol / L... -1 The negative electrode sheet was immersed in a 1 mol L solution of neutral K2SO4 electrolyte. -1 Aqueous dual-ion batteries are obtained by using KOH alkaline electrolyte solution.

[0053] The invented aqueous zinc-based dual-ion battery has a voltage window as high as 2.6V and a discharge plateau of approximately 2.2V; at 0.2Ag -1 At current density, the discharge specific capacity reaches as high as 113 mAh g. -1 Energy density approximately 106 Wh / kg -1 After 300 charge-discharge cycles, its discharge specific capacity is 95 mAh g. -1 It exhibits a capacity retention rate of up to 84%, demonstrating high discharge specific capacity, high energy density, and good charge-discharge cycle life.

[0054] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made to the technical solutions and inventive concepts of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-voltage aqueous zinc-based dual-ion battery based on Prussian blue cathode material, characterized in that, Includes the following steps: (1) Preparation of potassium-containing Prussian blue positive electrode sheet 2 mmol of potassium ferrocyanide was dissolved in 100 ml of deionized water to prepare a solution. Then, 10 mmol of potassium chloride, 5 ml of hydrochloric acid, and 2 g of polyvinylpyrrolidone were added to the solution respectively. The mixture was reacted in a water bath at 80°C for 12 hours, followed by standing for 12 hours. The sample was collected by centrifugation and finally dried to obtain potassium-containing Prussian blue material. The molecular formula of the potassium-containing Prussian blue material is K2FeFe(CN). 6, The potassium-containing Prussian blue material has a spherical morphology with a particle size of 200-300 nanometers. Potassium Prussian blue material, acetylene black and polytetrafluoroethylene are mixed in a mass ratio of 8:1:1, N-methylpyrrolidone is added to make the three into a paste, and the paste is repeatedly rolled into a thin sheet. The sheet is pressed onto a cut nickel mesh to make an electrode sheet, and then dried in a vacuum drying oven for 24 hours to obtain the Prussian blue positive electrode sheet. (2) Preparation of zinc negative electrode sheet The zinc foil is cut into appropriate sizes, then cleaned with dilute sulfuric acid and deionized water, and finally vacuum dried at room temperature for 24 hours in a vacuum drying oven at 80°C to obtain the negative electrode sheet. (3) Assemble an aqueous dual-ion battery First, place the cation permeable membrane in the middle of the H-type electrolytic cell to separate the positive and negative electrode parts; then, take the Prussian blue positive electrode sheet prepared in step (1) and the negative electrode sheet prepared in step (2), wherein the mass ratio of the negative electrode sheet to the Prussian blue positive electrode sheet is 1:(8~10); finally, immerse the Prussian blue positive electrode sheet in a neutral electrolyte solution and immerse the negative electrode sheet in an alkaline electrolyte solution to obtain an aqueous dual-ion battery; The high-voltage aqueous zinc-based dual-ion battery based on Prussian blue cathode material includes a cathode, a negative electrode, a separator, and two aqueous electrolytes; the cathode includes a cathode active material, acetylene black, and polytetrafluoroethylene; the cathode active material is a potassium-containing Prussian blue material. The two aqueous electrolyte solutions are an alkaline electrolyte solution and a neutral electrolyte solution; the alkaline electrolyte solution is a potassium hydroxide solution, and the neutral electrolyte solution is a potassium sulfate solution. The concentration of the alkaline electrolyte solution is 0.5-1 mol / L. -1 ; The concentration of the neutral electrolyte solution is 0.5-1 mol / L. -1 .

Images