Aqueous zinc ion battery construction system for realizing selenium-oxygen-bismuth cathode interface collaborative engineering
By preparing bismuth selenide-oxygen cathode material through a one-step oil bath method and combining it with ammonium iodide-modified electrolyte, the problems of low conductivity and poor structural stability of aqueous zinc-ion battery cathode materials were solved, achieving high discharge specific capacity and excellent cycle performance, simplifying the production process and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUNAN UNIV
- Filing Date
- 2026-01-27
- Publication Date
- 2026-04-21
AI Technical Summary
Existing aqueous zinc-ion battery cathode materials suffer from low conductivity, poor structural stability, and slow ion transport kinetics, leading to capacity decay. Furthermore, existing synthesis techniques are cumbersome, require significant equipment investment, and have long production cycles.
A one-step oil bath method was used to prepare bismuth selenide-oxygen cathode materials, which were then combined with ammonium iodide-modified electrolyte. Through cathode-electrolyte synergistic engineering, the production steps were simplified and the cycle stability of the battery was improved.
It achieves high discharge specific capacity and excellent cycle performance, simplifies the production process, reduces resource costs, and improves the long-cycle stability of aqueous zinc-ion batteries.
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Figure CN121894618A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of aqueous zinc-ion batteries, and relates to a method for preparing high-performance cathode materials for aqueous zinc-ion batteries, particularly a method for preparing a bismuth selenide-oxygen cathode material. Furthermore, by introducing electrolyte additives and achieving long-cycle high performance in aqueous zinc-ion batteries through cathode-electrolyte synergistic engineering, the application of zinc-ion batteries in the energy storage field is significantly improved. Background Technology
[0002] Driven by the "dual-carbon" strategic goal, the demand for efficient and safe energy storage technologies is increasingly urgent. However, commercial lithium-ion batteries suffer from limitations such as high cost and significant safety risks, making aqueous zinc-ion batteries (AZIBs) one of the ideal candidates for next-generation energy storage systems. With the continuous growth of energy demand and increasing environmental awareness, aqueous zinc-ion batteries are considered highly promising energy storage devices due to their high safety, low cost, and high theoretical capacity. Zinc-ion batteries (AZIBs) have gained widespread attention due to their inherent safety, abundant resources, environmental friendliness, high theoretical specific capacity (820 mA h g⁻¹), and relatively low redox potential (-0.76 V vs. standard hydrogen electrode). However, existing aqueous zinc-ion battery systems cannot provide satisfactory energy density and specific capacity. In recent years, researchers have focused primarily on the construction of electrolytes and intrinsic cathode materials. Cathode materials mainly include vanadium-based, manganese-based compounds, Prussian blue analogs, and organic materials, but these intrinsic materials often suffer from low conductivity, poor structural stability, and slow ion transport kinetics, which easily lead to capacity decay. The construction of the electrolyte involves broadening the electrochemical window of the electrolyte and controlling the interface engineering between the electrode and the electrolyte. Bismuth-based compounds, as low-cost and non-toxic layered materials, are a novel candidate for high-performance cathodes in AZIBs. Their bismuth-based selenides and tellurides exhibit stable electrochemical activity. Crucially, bismuth ions, selenium ions, and oxygen ions in bismuth-based selenides exhibit strong synergistic effects, significantly enhancing proton affinity and electrode stability in weakly acidic electrolytes. Therefore, they can effectively activate the proton storage function of zinc ions (Zn2+) in acidic zinc-based ion batteries (AZIBs). To date, the synthesis techniques for bismuth selenide-oxygen-bismuth cathode materials mainly involve high-temperature, high-pressure hydrothermal methods, chemical vapor deposition, or molten salt methods. These synthesis techniques are cumbersome, require significant equipment investment, and have long production cycles. This invention proposes a one-step oil bath method for preparing bismuth selenide-oxygen-bismuth cathode materials, which will greatly simplify the production process, couple ammonium iodide as an electrolyte additive for synergistic control, and can be extended to other multivalent ion storage systems. Summary of the Invention
[0003] The purpose of this invention is to provide a method for preparing a bismuth selenide-oxygen cathode material for aqueous zinc-ion batteries. The method uses a one-step oil bath, which is environmentally friendly, simple, and saves resources and costs. The cathode, combined with the interface regulation of ammonium iodide modified electrolyte, jointly improves the high performance and long-cycle stability of aqueous zinc-ion batteries. To achieve the above objective, the technical solution adopted by this invention is as follows: (1) dissolve selenium powder in an alkaline solution by magnetic stirring, and stir for a period of time after raising the temperature to a certain level; (2) dissolve bismuth salt in an acidic aqueous solution by magnetic stirring, and stir to dissolve; (3) add a chelating agent to the solution obtained in step (2) and stir to mix it; (4) add the solution obtained in step (3) dropwise to the solution obtained in step (1), stir the mixed solution for a period of time at a certain temperature, cool to room temperature, collect the black precipitate by centrifugation, wash repeatedly with deionized water and anhydrous ethanol, and dry to obtain the bismuth selenide-oxygen material. Preferably, the alkaline solution in step (1) is a sodium hydroxide solution with a concentration of 200-400 mg / ml. Preferably, in step (1), the temperature is increased to 70-100 ℃ and the stirring time is 30-120 min. Preferably, in step (2), the bismuth salt is any one of bismuth nitrate pentahydrate, bismuth chloride, or bismuth sulfate. Preferably, in step (2), the acidic solution is one or a mixture of acetic acid solution and formic acid solution, with a concentration of 1-3 mol / L. Preferably, in step (3), the chelating agent is any one or a mixture of disodium ethylenediaminetetraacetate, diethylenetriaminepentamethylphosphonic acid, sodium citrate, tetrasodium glutamate diacetate, or phytic acid. Preferably, in step (4), the centrifugation speed is 6000-10000 rpm; the drying temperature is 60-100 ℃; and the drying time is 12-24 h. The selenium oxybismuth prepared by the one-step oil bath method of the present invention is used as a cathode material for aqueous zinc-ion batteries. The present invention also provides an electrolyte system that can achieve selenium oxybismuth cathode regulation, including a soluble zinc salt electrolyte, a solvent, and ammonium iodide. Preferably, the concentration of ammonium iodide in the electrolyte is 0.03 M to 0.15 M (mol / L). More preferably, the optimal concentration of ammonium iodide in the electrolyte is 0.1 M. This preferred concentration was determined after systematic electrochemical testing of electrolytes with different concentrations of additives (0.03 M, 0.05 M, 0.07 M, 0.1 M, 0.15 M), achieving an optimal balance between battery cycle life, rate performance, and additive cost. Preferably, the soluble zinc salt electrolyte is any one or a mixture of 1-2 M zinc sulfate, zinc perchlorate, and zinc iodide. This invention also applies this electrolyte to zinc-ion batteries, i.e., assembling the electrolyte with a cathode, anode, and separator. This additive can also be applied to aqueous zinc-ion batteries using other cathode materials.Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention prepares a novel bismuth selenide-oxygen cathode material for aqueous zinc-ion batteries using a one-step oil bath method. The preparation method is simple and easy to operate, and the process is easy to implement. Furthermore, the ammonium iodide modified electrolyte is used to synergistically regulate the bismuth selenide-oxygen cathode material to exhibit high discharge specific capacity and excellent cycle performance. Attached Figure Description Figure 1 is the XRD pattern of the bismuth selenide cathode material obtained according to Example 1; Figure 2 is a SEM image of the bismuth selenide cathode material obtained according to Example 1; Figure 3 shows the cycling performance of the full cells A1 of Comparative Example 1 and A1 of Comparative Example 2 at a current density of 1 Ag⁻¹. Figure 4 shows the constant current charge-discharge curves of the A full battery of Comparative Example 1 at different numbers of cycles. Figure 5 shows the CV curve of the A full cell of Comparative Example 1 at a scan rate of 0.1 mV s⁻¹. Figure 6 shows high-magnification scanning electron micrographs (SEM) of the zinc foil surface after 50 cycles of the full cells A1 in Comparative Example 1 and A1 in Comparative Example 2. Detailed Implementation
[0004] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and comparative experiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention. Modifications, substitutions, and alterations made by those skilled in the art to the following embodiments based on an understanding of the spirit of the invention are all within the scope of protection of this invention. The method for testing the electrochemical performance of the cathode materials obtained in the embodiments in an aqueous zinc-ion battery is as follows: The cathode materials obtained in each embodiment are mixed with conductive carbon black and PVDF at a mass ratio of 7:2:1, and an appropriate amount of NMP is added and stirred to form a slurry. This slurry is then coated onto a stainless steel foil of a certain thickness, dried, and cut into cathode sheets. A CR2032 coin cell is assembled using zinc foil as the anode sheet, GF / D glass fiber (Whatman) as the separator, gaskets, spring sheets, and positive and negative electrode shells. Example 1: This example describes the preparation of a bismuth selenide-oxygen cathode material according to the following steps: 1. Weigh 0.3 g of selenium powder and disperse it in 40 ml (250 mg / ml) sodium hydroxide solution using magnetic stirring. Stir continuously at 85°C for 40 min to obtain solution a. During this process, solution a changes from colorless to red and finally to dark red. 2. Disperse 1.2127 g of bismuth nitrate pentahydrate in 50 ml of acetic acid aqueous solution (acetic acid:deionized water = 1:9) and stir magnetically until a clear solution b is obtained. 3. Weigh 3.35 g of disodium ethylenediaminetetraacetate and add it to solution b. Stir continuously until completely dissolved, resulting in a milky white solution, which is designated as solution c. Then, add solution c dropwise to solution a and stir the mixture for 1 h. 4. Samples were centrifuged at 8000-10000 rpm and washed three times alternately with deionized water and anhydrous ethanol. The samples were then dried at 80 °C for 12 h to obtain powdered bismuth selenide. Example 21: 0.3 g of selenium powder was weighed and dispersed in 40 ml (250 mg / ml) sodium hydroxide solution by magnetic stirring, and stirred continuously at 85 °C for 40 min to obtain solution a. During this process, solution a changed from colorless to red and finally to dark red. 2. 0.8827 g of bismuth sulfate was dispersed in 50 ml of acetic acid aqueous solution (acetic acid:deionized water = 1:9) and stirred magnetically until a clear solution b was obtained. 3. 3.51 g of tetrasodium diacetate of glutamic acid was weighed and added to solution b, and stirred continuously until completely dissolved. The solution turned milky white and was recorded as solution c. Then, solution c was added dropwise to solution a, and the mixture was stirred for 1 h.4. Samples were centrifuged at 8000-10000 rpm and washed three times alternately with deionized water and anhydrous ethanol. The samples were then dried at 80 °C for 12 h to obtain powdered bismuth selenide. Example 31: 0.3 g of selenium powder was weighed and dispersed in 40 ml (250 mg / ml) sodium hydroxide solution by magnetic stirring, and stirred continuously at 85 °C for 40 min to obtain solution a. During this process, solution a changed from colorless to red and finally to dark red. 2. 0.7884 g of bismuth chloride was dispersed in 50 ml of acetic acid aqueous solution (acetic acid:deionized water = 1:9) and stirred magnetically until a clear solution b was obtained. 3. 2.94 g of sodium citrate was weighed and added to solution b, and stirred continuously until completely dissolved. The solution turned milky white and was recorded as solution c. Then, solution c was added dropwise to solution a, and the mixture was stirred for 1 h. 4. Samples were centrifuged at 8000-10000 rpm and washed three times alternately with deionized water and anhydrous ethanol. The samples were then dried at 80 °C for 12 h to obtain powdered bismuth selenide. Comparative Example 1: Preparation of the optimal electrolyte: 28.756 g of zinc sulfate heptahydrate and 0.7247 g of ammonium iodide were weighed and dissolved in 50 ml of deionized water. The solution was stirred thoroughly until completely dissolved, and then brought to a final volume to obtain an aqueous zinc-ion battery electrolyte. Aqueous zinc-ion full batteries assembled using the cathode materials prepared according to Examples 1, 2, and 3 were designated A, B, and C, respectively. Comparative Example 2: This comparative example provides a control electrolyte without any additives. Only 28.756 g of zinc sulfate heptahydrate was weighed and dissolved in 50 ml of deionized water. The solution was stirred thoroughly until completely dissolved, and then brought to a final volume to obtain an aqueous zinc-ion battery electrolyte. Using this electrolyte, aqueous zinc-ion full cells assembled with cathode materials prepared according to Examples 1, 2, and 3 were designated A1, B1, and C1, respectively. Preparation of other electrolytes in Comparative Example 3: 28.756 g of zinc sulfate heptahydrate and 0.21744 g of ammonium iodide were weighed and dissolved in 50 ml of deionized water. The solution was stirred thoroughly until completely dissolved, and then brought to a final volume to obtain an aqueous zinc-ion battery electrolyte. Using this electrolyte, aqueous zinc-ion full cells assembled with cathode materials prepared according to Examples 1, 2, and 3 were designated A2, B2, and C2, respectively.
[0005] Results Analysis: Figure 1 shows the XRD pattern of the bismuth selenide-oxygen material obtained in Example 1, corresponding to the standard card PDF #25-1463. Figure 2 shows the scanning electron micrograph (SEM) image of the bismuth selenide-oxygen material obtained in Example 1. Figure 3 shows the cycling performance of the full cells A1 of Comparative Example 1 and A1 of Comparative Example 2 at a current density of 1 A g⁻¹. From... Figure 2 As can be seen, the Zn||Bi₂SeO₂ full cell with an electrolyte containing 0.1 M ammonium iodide still exhibits good long-term cycling performance after 200 cycles, with a capacity of 315.6 mA h g⁻¹. This indicates that the addition of ammonium iodide effectively modifies the cycling performance and stability of bismuth selenide-oxygenate. Figure 4 shows the constant current charge-discharge curves of the A full cell of Comparative Example 1 after different number of cycles. The figure shows that the cell capacities at 5, 50, 100, and 200 cycles are 480.6 mA h g⁻¹, 354.2 mA h g⁻¹, 335.9 mA h g⁻¹, and 315.3 mA h g⁻¹, respectively. The improved cycling performance indicates that the ammonium iodide electrolyte additive plays an important role. Figure 5 shows the CV curve of the A full cell of Comparative Example 1 at a scan rate of 0.1 mV s⁻¹. Figure 6 shows high-magnification scanning electron microscopy (SEM) images of the zinc foil surface after 50 cycles of the full cells A in Comparative Example 1 and A1 in Comparative Example 2. In the full cell containing ammonium iodide electrolyte, the zinc foil is densely and vertically stacked on the zinc anode surface with a specific orientation. This uniform Zn deposition morphology means that the Zn2+ flux is uniform and the nucleation sites are uniform. This unique vertical stacking mode can induce uniform Zn deposition, thereby improving the long-cycle performance of aqueous zinc-ion batteries. In contrast, in the full cell without ammonium iodide electrolyte, the zinc foil exhibits a disordered arrangement on the anode surface, which easily leads to the formation of dead zinc, accumulation of by-products, and even puncture of the separator. Table 1 compares the capacity of the full cells A, B, and C in Comparative Example 1, A1, B1, and C1 in Comparative Example 2, and A2, B2, and C2 in Comparative Example 3 after 50 cycles at 1 Ag-1. As can be clearly seen from Table 1, the full cell performance of the ammonium iodide electrolyte is far superior to that of the pure zinc sulfate electrolyte. Among different concentrations of ammonium iodide, the performance is optimal when 0.1 M ammonium iodide is added.
[0006] Battery Type A A1 A2 B B1 B2 C C1 C2 Specific capacity of discharge over 50 cycles at 1 Ag⁻¹ (mA h g⁻¹) 354.2 211.5 324.3 343.1 208.4 315.2 348.8 210.6 318.7 Table 1 Table 2 compares the cycle performance of the full cell assembled with bismuth selenide-oxygen cathode material and electrolyte A with that of other reported bismuth-based cathode materials in different electrolytes. Table 2 further demonstrates that the ammonium iodide additive significantly improves the cycle performance of the full cell, achieving a capacity of 396.2 mA hg⁻¹ at a current density of 1 Ag⁻¹, far superior to other reported bismuth-based cathode materials and modified electrolyte strategies.
[0007] Cathode Electrolyte Specific capacity (mA h g-1) Bi2Te3@ppy 2 M ZnSO4 314.3 Bi2Te3 1 M ZnSO4 224.8 Bi2Se3 2 M ZnSO4 311 Cu-Bi2-xSe3 1 M ZnSO4 156.8 Bi2Se3 / NCDs 2 M ZnSO4 162 Bi2O3 1 M ZnSO4 + 0.3 M KI 211 BiOI 1 M Zn(CF3SO4)2 + 0.2 M ZnI2 311 Bi2SeO2 2 M ZnSO4 + 0.1 M NH4I 396.2 Table 2
Claims
1. A method for preparing a bismuth selenide-oxygen cathode material for aqueous zinc-ion batteries, characterized in that, The process includes the following steps: (1) dissolving selenium powder in an alkaline solution by magnetic stirring, raising the temperature to a certain level and stirring for a period of time; (2) dissolving bismuth salt in an acidic aqueous solution by magnetic stirring; (3) adding a chelating agent to the solution obtained in step (2) and stirring to make it evenly mixed; (4) adding the solution obtained in step (3) dropwise to the solution obtained in step (1), stirring the mixed solution at a certain temperature for a period of time, cooling to room temperature, centrifuging and collecting the black precipitate, washing it repeatedly with deionized water and anhydrous ethanol, and drying to obtain bismuth oxy selenide material.
2. The method for preparing the bismuth selenide-oxygen cathode material as described in claim 1, characterized in that, In step (1), the temperature is increased to 70-100 ℃ and the stirring time is 30-120 min.
3. The method for preparing the bismuth selenide-oxygen cathode material as described in claim 1, characterized in that, In step (2), the bismuth salt is any one or a mixture of bismuth nitrate pentahydrate, bismuth chloride, and bismuth sulfate.
4. The method for preparing the bismuth selenide-oxygen cathode material as described in claim 1, characterized in that, In step (2), the acidic solution is one or a mixture of acetic acid solution and formic acid solution, with a concentration of 1 to 3 mol / L.
5. The method for preparing the bismuth selenide-oxygen cathode material as described in claim 1, characterized in that, In step (3), the chelating agent is any one or a mixture of ethylenediaminetetraacetic acid disodium salt, diethylenetriaminepentamethylphosphonic acid, sodium citrate, tetrasodium diacetate of glutamate, phytic acid, etc.
6. Use of the bismuth selenide prepared by the preparation method according to any one of claims 1 to 5 as a cathode material for an aqueous zinc-ion battery.
7. An electrolyte for an aqueous zinc-ion battery, characterized in that, This includes soluble zinc salt electrolytes, solvents, and ammonium iodide.
8. The battery electrolyte as described in claim 7, characterized in that, The concentration of ammonium iodide in the electrolyte is 0.03 M to 0.15 M.
9. The battery electrolyte as described in claim 7, characterized in that, Preferably, the soluble zinc salt electrolyte is any one or a mixture of 1-2 M zinc sulfate, zinc perchlorate, zinc iodide, etc.
10. An aqueous zinc-ion battery, characterized in that, The cathode described in any one of claims 1 to 9 is assembled with an electrolyte, a zinc anode, and a separator to form an aqueous rechargeable zinc battery.