A positive electrode sheet of aqueous organic zinc ion battery, a preparation method thereof and an aqueous organic zinc ion battery made of the same

Abstract

The application provides a water-based organic zinc ion battery positive electrode sheet, which is composed of a positive electrode organic active substance, a conductive agent, a binder and a current collector; and the positive electrode organic active substance is 3,3'-di[1,4]benzoxazino[2,3,4-KL]phenoxazine. The application uses 3,3'-di[1,4]benzoxazino[2,3,4-KL]phenoxazine as the positive electrode organic active substance, combines the conductive agent and the binder, and prepares the positive electrode sheet through a coating method. The water-based zinc ion battery prepared by the application has high safety, good cycle performance under a large current density (3 A / g), a high charge-discharge window, low preparation cost and environmental friendliness. In addition, the material for preparing the battery is very rich in nature. The application has development prospects in the fields of future energy storage, 3C equipment power supply and power equipment power supply.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of zinc ion batteries, and mainly relates to a water-based organic zinc ion battery positive electrode sheet, a preparation method thereof and a water-based organic zinc ion battery made of the same. BACKGROUND

[0002] Although current high-energy-density lithium-ion batteries (LIBs) have dominated the market of commercial rechargeable batteries, the limited nature of lithium resources, high cost, and safety issues of organic electrolytes have limited their further development. Water-based zinc ion batteries (ZIBs) have attracted attention due to their aqueous electrolyte, low cost, environmental friendliness, and high safety. Zinc metal is an ideal negative electrode material due to its high theoretical capacity (820 mAh / g) and low redox potential (-0.76 V vs SHE). ZIBs are considered ideal green battery systems due to their high power density, easy preparation, and low cost.

[0003] Among the positive electrode materials of ZIBs, common ones include manganese-based oxides, vanadium-based compounds, traditional inorganic materials such as Prussian blue, and organic compounds. These materials can reversibly intercalate and deintercalate Zn 2+ due to their special internal structure, thereby storing energy. Organic compounds are valued for their high discharge specific capacity, high discharge platform, structural diversity, and adjustability, and can be optimized for electrochemical performance, resource renewability, and environmental friendliness by changing the molecular structure.

[0004] In terms of process preparation of organic positive electrode materials, compared with inorganic materials, organic positive electrode materials exhibit unique advantages in water-based zinc ion batteries. Although inorganic materials such as functional glass and catalytic and environmentally friendly ceramics have irreplaceable roles in certain fields, in the field of batteries, the adjustability and environmental friendliness of organic materials make them more attractive. The multiple active centers and low "dead mass" of organic materials allow them to have a large theoretical specific capacity and actual capacity, and although their voltage is low, their performance can be significantly improved through optimization of structure and preparation process.

[0005] In the prior art, there are several reports of using aromatic heterocyclic materials as positive electrode materials. However, the positive electrode materials of the prior art often have problems such as dispersed free radical electrons, many free radical side reactions, or insufficient structural stability after oxidation, which leads to poor cycle stability of the zinc batteries prepared therefrom and low charging and discharging efficiency at high current density.

[0006] Therefore, the development of high-performance organic positive electrode materials not only meets the development needs of future energy storage technology, but also is expected to play an important role in electric vehicles, large-scale energy storage, and portable electronic devices. Through continuous material innovation and process optimization, organic positive electrode materials are expected to become a key component of future energy storage technology.

[0007] Therefore, it is necessary to develop a new technical solution to solve the defects and deficiencies in the prior art. SUMMARY

[0008] To solve the problems mentioned above in the development of lithium batteries in the future, the present application provides a kind of water-based organic zinc ion battery positive pole piece and its preparation method and water-based organic zinc ion battery made of it. The battery uses 3,3'-di [1,4] benzoxazine [2,3,4-KL] phenoxazine (BBOPO) as the positive organic active material, combined with conductive agent and binder, and the positive pole piece is prepared by coating method. The specific steps include mixing, grinding, coating, drying, punching and assembling. The water-based zinc ion battery prepared by the present application has high safety, good cycle performance at a large current density (3A / g), high charge-discharge window, low preparation cost and environmental friendliness. In addition, the content of the material for preparing the battery in nature is very rich, especially the zinc ore reserves about 230 million tons in the world. The present application has development prospects in the fields of future energy storage, 3C equipment power supply and power equipment power supply.

[0009] One object of the present application is to provide a water-based organic zinc ion battery positive pole piece, which comprises a current collector and a positive active layer disposed on the current collector.

[0010] The positive active layer is composed of a positive organic active material, a conductive agent and a binder.

[0011] The positive organic active material is 3,3'-di [1,4] benzoxazine [2,3,4-KL] phenoxazine.

[0012] Figure 1 The molecular structure of the positive organic active material BBOPO is shown.

[0013] Further, the conductive agent is selected from one or more of carbon black (CB), graphene, acetylene black (ACET) or ketjen black (KB).

[0014] Further, the binder is selected from one or more of PTFE or PVDF.

[0015] Further, the current collector is selected from one or more of carbon cloth, titanium mesh or stainless steel mesh.

[0016] Further, the mass ratio of the positive organic active material, conductive agent and binder is 1:(0.5-1.5):(0.1-1).

[0017] Another object of the present application is to provide a preparation method of the above-mentioned water-based organic zinc ion battery positive electrode sheet, comprising the following steps:

[0018] S1, blending, grinding and uniformly mixing the positive electrode organic active material, the conductive agent and the binder to obtain a slurry;

[0019] S2, coating the slurry on the current collector to form a positive electrode active layer, heating and drying, and then cutting to obtain the water-based organic zinc ion battery positive electrode sheet.

[0020] Further, in step S1, the grinding time is 5-60 min.

[0021] Further, in step S2, the coating method is selected from one or more of wet coating, roller coating, extrusion or dip coating.

[0022] Further, in step S2, the coating load is in the range of 0.5-20 mg / cm 2 .

[0023] Further, in step S2, the heating temperature is 45-200℃, and the drying time is 30-3600 min.

[0024] Another object of the present application is to provide a water-based organic zinc ion battery containing the above-mentioned water-based organic zinc ion battery positive electrode sheet, wherein the water-based organic zinc ion battery is a multi-layer structure,

[0025] wherein the negative electrode sheet, the separator and the positive electrode sheet are in a sandwich structure.

[0026] The electrolyte exists between the positive electrode sheet and the negative electrode sheet, and the separator is fully infiltrated by the electrolyte.

[0027] Further, the water-based organic zinc ion battery is a multi-layer structure, comprising from top to bottom: a negative electrode shell, a negative electrode sheet, a separator, a positive electrode sheet, a gasket, a grommet and a positive electrode shell.

[0028] Further, the negative electrode sheet is a polished zinc sheet.

[0029] Further, the negative electrode sheet is a 100% pure zinc sheet polished by sandpaper, and the mesh number of the sandpaper is 800-2000.

[0030] Further, the electrolyte is selected from one or more of zinc sulfate (ZnSO4) solution, zinc triflate (Zn(OTF)2) solution or zinc chloride (ZnCl2) solution.

[0031] Further, the concentration of the electrolyte is 0.5-8M.

[0032] Further, the diaphragm is glass fiber.

[0033] The present application has the following advantages:

[0034] (1) The present application proposes a water-based organic zinc ion battery positive electrode sheet, a preparation method thereof, and a water-based organic zinc ion battery made therefrom. In the water-based organic zinc ion battery positive electrode sheet, an organic material, 3,3'-di[1,4]benzoxazine[2,3,4-KL]phenoxazine (BBOPO), is used as the positive electrode organic active material. As a kind of condensed heterocyclic compound, BBOPO has active sites in the reaction process due to the existence of lone pair electrons, and heteroatoms such as N or O are considered to be redox-active parts, which shows good electrochemical activity. In addition, systematic redox chemical studies show that the free radical electrons of oxidized BBOPO ·+ mainly gather around N and O atoms and further delocalize to the entire conjugated structure, which plays an important role in the stability of the free radical species BBOPO ·+ , reduces the occurrence of free radical side reactions, and is not easy to decompose at high current density, with good reversibility of electrochemical reaction. Moreover, the molecular structure of BBOPO is centrosymmetric, and even better structural stability and enhanced aromaticity can be shown after oxidation, indicating that it has advantages in battery cycle stability, so that the battery containing this zinc ion battery positive material can have high capacity and long cycle capacity retention rate at high current density. At the same time, during charging and discharging, the active sites (O) of BBOPO can couple with zinc ions to form coordination bonds, and there are four active sites, which can provide considerable capacity at high current density, and the large benzene ring / fused ring can inhibit degradation during the cycle process, thereby further enhancing the cycle stability of zinc battery and the charging and discharging efficiency at high current density.

[0035] (2) Great safety: The water-based organic zinc ion battery of the present application uses an aqueous solution as the electrolyte, which makes it superior to lithium ion batteries in terms of safety. Due to its high safety, the water-based zinc battery has lower risk during operation and storage, avoiding safety hazards such as high temperature and combustion that may occur in lithium ion batteries, which is particularly important for large-scale energy storage applications.

[0036] (3) High capacity retention rate at high current density: The water-based organic zinc ion battery of the present application has excellent electrochemical performance, which can achieve faster charging and discharging while still maintaining high battery capacity. Experiments show that the battery using the new material can still perform stable charging and discharging at high current density, with little loss of capacity retention rate, and can be charged / discharged to the target capacity in a short time, while the traditional material needs more time, greatly enhancing the charging and discharging performance of the battery.

[0037] (4) Cost-effectiveness: The aqueous organic zinc ion battery of the present application, although providing the above performance advantages, does not significantly increase the production cost compared with traditional batteries. Moreover, the total global zinc resource reserves are much higher than the global lithium resource reserves, which provides raw material guarantee for the large-scale application of zinc ion batteries. In addition, the production process of aqueous zinc battery is simple and can be assembled in air, which may be more cost-effective after large-scale production.

[0038] (5) Better environmental friendliness: The aqueous organic zinc ion battery of the present application uses environmentally friendly electrolyte, reduces environmental pollution, and has lower toxicity than lithium batteries, which can cause nickel, cobalt, fluorine pollution, organic matter, dust, acid and alkali pollution. The organic materials used are biodegradable, less polluting to the ecological environment, and the discarded batteries are better recycled and treated, which is an ideal environmentally friendly battery.

[0039] (6) Scheme scalability: The method of the present application has good scheme scalability and can be adjusted and optimized according to different application requirements. For different types and structures of positive electrode organic active materials, the performance of zinc battery can be further improved. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 A molecular structure diagram of the positive electrode organic active material BBOPO is shown.

[0041] Figure 2 An assembly structure diagram of the aqueous organic zinc ion battery is shown.

[0042] Figure 3 A cycle performance diagram of the aqueous organic zinc ion battery prepared in Application Example 1 is shown.

[0043] Figure 4 A cycle performance diagram of the aqueous organic zinc ion battery prepared in Application Example 2 is shown.

[0044] Figure 5 A rate performance diagram of the aqueous organic zinc ion battery prepared in Application Example 1 is shown.

[0045] Figure 6 A rate performance diagram of the aqueous organic zinc ion battery prepared in Application Example 2 is shown. DETAILED DESCRIPTION

[0046] In order to more clearly illustrate the technical solutions of the present application, the following examples are listed. The raw materials, reactions and post-treatment methods appearing in the examples are all common raw materials on the market and well-known technical means to those skilled in the art, unless otherwise stated.

[0047] The words "preferred" and "preferably" in the present invention refer to embodiments of the present invention that can provide certain benefits under certain circumstances. However, other embodiments can also be preferred under the same or other circumstances. Additionally, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude those other embodiments from the scope of the present invention.

[0048] It should be understood that, except in any operating example, or otherwise indicated herein and that the use of amounts or all numbers expressing compositions in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, numerical parameters set forth in the following specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the present invention.

[0049] Example 1

[0050] A water-based organic zinc ion battery positive electrode sheet, the water-based organic zinc ion battery positive electrode sheet comprising a current collector carbon cloth and a positive electrode active layer disposed on the carbon cloth;

[0051] The positive electrode active layer is composed of a positive electrode organic active substance BBOPO, a conductive agent graphene, and a binder PTFE.

[0052] The preparation method of the above water-based organic zinc ion battery positive electrode sheet comprises the following steps:

[0053] S1, blending BBOPO, graphene and PTFE (BBOPO: graphene: PTFE = 2:2:1, m / m / m), grinding uniformly for 30 min to obtain a slurry;

[0054] S2, coating the slurry on the carbon cloth using a wet coating method to form a positive electrode active layer, the loading capacity being 10 mg / cm 2 ; placing in a drying oven and drying at a temperature of 80°C for 360 min, then slitting and cutting to obtain a water-based organic zinc ion battery positive electrode sheet.

[0055] Example 2

[0056] A water-based organic zinc ion battery positive electrode sheet, the water-based organic zinc ion battery positive electrode sheet comprising a current collector titanium mesh and a positive electrode active layer disposed on the titanium mesh;

[0057] The positive electrode active layer is composed of a positive electrode organic active substance BBOPO, a conductive agent graphene, and a binder PTFE.

[0058] The preparation method of the above water-based organic zinc ion battery positive electrode sheet comprises the following steps:

[0059] S1, blend BBOPO, graphene and PTFE (BBOPO: graphene: PTFE = 2:2:1, m / m / m), grind uniformly for 30 min to obtain a slurry;

[0060] S2, coat the slurry on a titanium mesh to form a positive active layer using a wet coating method, the loading is 10 mg / cm 2 ; place in a drying oven and dry at 60°C for 480 min, then cut and slice to obtain a water-based organic zinc ion battery positive electrode sheet.

[0061] Application Example 1

[0062] A water-based organic zinc ion battery containing the water-based organic zinc ion battery positive electrode sheet prepared in Example 1, the water-based organic zinc ion battery is a multi-layer structure, from top to bottom including: a negative shell, a negative electrode sheet, a separator, a positive electrode sheet, a gasket, a gasket, and a positive shell.

[0063] Among them, the negative electrode sheet, the separator, and the positive electrode sheet are in a sandwich structure;

[0064] The electrolyte exists between the positive electrode sheet and the negative electrode sheet, and the separator is fully infiltrated by the electrolyte;

[0065] The negative electrode sheet is a 100% pure zinc sheet polished by 1000 mesh sandpaper; the separator is glass fiber; and the electrolyte is a Zn(OTF)2 aqueous solution with a concentration of 3M.

[0066] The preparation method of the above water-based organic zinc ion battery comprises the following steps:

[0067] Assemble the negative shell, the negative electrode sheet, the separator, the positive electrode sheet, the gasket, the gasket, and the positive shell in order from top to bottom, inject the electrolyte when assembling the separator to fully infiltrate the separator, and then seal and form by extrusion through a battery sheeting machine to obtain a water-based organic zinc ion battery.

[0068] Figure 2 The assembly structure of the water-based organic zinc ion battery is shown.

[0069] Application Example 2

[0070] A water-based organic zinc ion battery containing the water-based organic zinc ion battery positive electrode sheet prepared in Example 2, the water-based organic zinc ion battery is a multi-layer structure, from top to bottom including: a negative shell, a negative electrode sheet, a separator, a positive electrode sheet, a gasket, a gasket, and a positive shell.

[0071] Among them, the negative electrode sheet, the separator, and the positive electrode sheet are in a sandwich structure;

[0072] The electrolyte exists between the positive electrode sheet and the negative electrode sheet, and the separator is fully infiltrated by the electrolyte;

[0073] The negative electrode sheet is a 100% pure zinc sheet polished by 1000-mesh sandpaper; the separator is glass fiber; and the electrolyte is a Zn(OTF)2 aqueous solution with a concentration of 3M.

[0074] The preparation method of the aqueous organic zinc ion battery includes the following steps:

[0075] The negative electrode shell, the negative electrode sheet, the separator, the positive electrode sheet, the gasket, the grommet, and the positive electrode shell are assembled in order from top to bottom, the electrolyte is injected when the separator is assembled to fully soak the separator, and after the assembly is completed, the battery is extruded and sealed by a battery pressing machine to form an aqueous organic zinc ion battery.

[0076] Test Example

[0077] The aqueous organic zinc ion battery prepared in Application Example 1-2 is placed in an electrochemical workstation for battery electrical performance testing.

[0078] Test Method:

[0079] Battery cycle performance: Set the work sequence: standing, constant current charging, and constant current discharging, set the current density to 3A / g, and set the cycle number to 500 cycles.

[0080] Battery rate performance: Set multiple groups of work sequences: standing, constant current charging, and constant current discharging, set the current density of each group to 0.5A / g, 1A / g, 1.5A / g, 2A / g, 2.5A / g, 3A / g, 4A / g, and 5A / g, and set the cycle number of each group to 10 cycles.

[0081] The battery cycle performance test results are shown in Table 1. Figure 3 The cycle performance of the aqueous organic zinc ion battery prepared in Application Example 1 is shown in the graph; Figure 4 The cycle performance of the aqueous organic zinc ion battery prepared in Application Example 2 is shown in the graph.

[0082] Table 1 Battery cycle performance test results of Application Examples 1-2

[0083]

[0084] From Table 1 and Figure 3 It can be seen that the charge-discharge specific capacity of the battery prepared in Application Example 1 is as high as 116.34mAh / g, and after 500 cycles of charge-discharge cycling, the charge-discharge specific capacity of the battery is still 105.5mAh / g, and the capacity retention rate is 90.7%; from Table 1 and Figure 4It can be seen that the charge-discharge specific capacity of the battery prepared in application example 2 is as high as 97.5 mAh / g, and after 500 cycles of charge-discharge, the charge-discharge specific capacity of the battery is still 94.4 mAh / g, and the capacity retention rate is 96.8%; it can be seen that the use of BBOPO material as the active material of the positive electrode sheet of the battery can effectively enhance the cycle stability of the battery.

[0085] The battery rate performance test results are shown in Table 2. Figure 5 The rate performance of the aqueous organic zinc ion battery prepared in application example 1 is shown in the figure; Figure 6 The rate performance of the aqueous organic zinc ion battery prepared in application example 2 is shown in the figure.

[0086] Table 2 Battery rate performance test results of application examples 1-2

[0087]

[0088] From Table 2 and Figure 5 It can be seen that the charge-discharge specific capacity of the battery prepared in application example 1 is 117.72 mAh / g, 116.59 mAh / g, 110.59 mAh / g, 107.49 mAh / g, 104.93 mAh / g, 102.86 mAh / g, 100.24 mAh / g, and 98.17 mAh / g under a series of high-rate current densities of 0.5 A / g, 1 A / g, 1.5 A / g, 2 A / g, 2.5 A / g, 3 A / g, 4 A / g, and 5 A / g, respectively. Because BBOPO is a fused ring macromolecule, it exhibits a lower coulombic efficiency under a small current density, but its activity gradually increases as the current density increases, and the coulombic efficiency remains at 99%. From the above test results, it can be seen that the charge-discharge specific capacity of the battery does not have much loss under a larger current density, and even the average charge-discharge specific capacity under a current density of 0.5 A / g in the last 10 cycles is still 118.98 mAh / g, with basically no capacity loss, showing excellent charge-discharge reversibility of the battery, and showing that the battery has extremely high charge-discharge efficiency under high current density.

[0089] From Table 2 and Figure 6It can be seen that the average charge-discharge specific capacity of the battery prepared in Application Example 2 at a series of high-rate current densities of 0.5 A / g, 1 A / g, 1.5 A / g, 2 A / g, 2.5 A / g, 3 A / g, 4 A / g, and 5 A / g is 96.49 mAh / g, 92.58 mAh / g, 88.46 mAh / g, 85.96 mAh / g, 84.32 mAh / g, 83.01 mAh / g, 81.12 mAh / g, and 79.7 mAh / g, and the coulombic efficiency is maintained at 99%. From the above test results, it can be seen that the charge-discharge specific capacity of the battery does not have much loss at a large current density, and even the average charge-discharge specific capacity at a current density of 0.5 A / g in the last 10 cycles is still 96.63 mAh / g, with basically no capacity loss, showing excellent charge-discharge reversibility of the battery and high charge-discharge efficiency of the battery at a high current density.

[0090] It is apparent to those skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments, and that the application can be implemented in other specific forms without departing from the spirit or essential characteristics of the application. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0091] Furthermore, it should be understood that, although the present specification is described in terms of embodiments, not every implementation can include every embodiment, and the description of an embodiment should not be interpreted as representing a limitation of the scope of the applications. The description of an embodiment is merely provided for the purposes of clarity and understanding, and those skilled in the art will understand that the specification is to be considered as a whole, and that each embodiment is merely one of many possible combinations of features.

Claims

1. A positive electrode sheet for an aqueous organic zinc ion battery, characterized by comprising: The water-based organic zinc ion battery positive electrode plate comprises a current collector and a positive active layer arranged on the current collector. The positive active layer is composed of a positive organic active material, a conductive agent and a binder. The positive organic active material is 3,3'-di[1,4]benzoxazino[2,3,4-KL]phenoxazine.

2. The aqueous organic zinc ion battery cathode electrode of claim 1, wherein, The conductive agent is selected from one or more of carbon black, graphene, acetylene black or ketjen black.

3. The aqueous organic zinc ion battery cathode electrode of claim 1, wherein, The binder is selected from one or more of PTFE or PVDF.

4. The aqueous organic zinc ion battery cathode electrode of claim 1, wherein, The current collector is selected from one or more of carbon cloth, titanium mesh or stainless steel mesh.

5. The aqueous organic zinc ion battery cathode electrode of claim 1, wherein, The mass ratio of the positive organic active material, the conductive agent and the binder is 1:(0.5-1.5):(0.1-1).

6. The method of making a positive electrode sheet for aqueous organic zinc ion batteries according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: S1, blending, grinding and uniformly mixing a positive organic active material, a conductive agent and a binder to obtain a slurry; S2, coating the slurry on a current collector to form a positive active layer, heating and drying, and then cutting to obtain a water-based organic zinc ion battery positive electrode plate.

7. The method for preparing the positive electrode sheet of an aqueous organic zinc-ion battery according to claim 6, characterized in that, In step S2, the heating temperature is 45-200℃, and the drying time is 30-3600min.

8. A water-based organic zinc-ion battery comprising the positive electrode sheet of the water-based organic zinc-ion battery according to any one of claims 1 to 5, characterized in that, The water-based organic zinc ion battery is a multi-layer structure, The negative electrode plate, the separator and the positive electrode plate are in a sandwich structure. The electrolyte exists between the positive electrode plate and the negative electrode plate, and the separator is fully infiltrated by the electrolyte.

9. The aqueous organic zinc ion battery of claim 8, wherein, The water-based organic zinc ion battery is a multi-layer structure, comprising, from top to bottom, a negative electrode shell, a negative electrode plate, a separator, a positive electrode plate, a gasket, a grommet and a positive electrode shell.

10. The aqueous organic zinc ion battery of claim 8, wherein, The electrolyte is selected from one or more of zinc sulfate solution, zinc triflate solution or zinc chloride solution.

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