Preparation method of c@bioi composite electrode material and application of c@bioi composite electrode material in aqueous zinc-iodine battery
By preparing C@BiOI composite electrode materials, the problems of slow iodine conversion kinetics and multiple iodide shuttle in aqueous zinc-iodine batteries were solved, improving the specific capacity and rate performance of the batteries and achieving high energy density and power density battery performance, which is suitable for large-scale production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LIAONING UNIVERSITY
- Filing Date
- 2025-01-06
- Publication Date
- 2026-07-14
Smart Images
Figure CN119812275B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of materials technology, specifically relating to a method for preparing C@BiOI composite electrode material and its application in aqueous zinc-iodine batteries. Background Technology
[0002] The energy crisis has become an urgent issue, prompting a continuous search for advanced energy storage systems that offer high economic efficiency, environmental friendliness, and long cycle life. Among energy storage solutions, lithium-ion batteries, with their high energy density and long cycle life, are widely used in solar and wind power generation systems as a clean energy storage solution. However, despite their excellent energy density and performance, the limited storage capacity of lithium-ion batteries increases dependence on scarce resources. Therefore, there is an urgent need to develop safe, reliable, and low-cost alternatives to meet the demands of rail transportation and next-generation electronic devices.
[0003] Rechargeable aqueous zinc-ion batteries (RAZBs) are considered a promising alternative to lithium-ion batteries due to their safe and reliable non-toxic aqueous electrolyte and the advantages of low cost, moderate redox potential, and high theoretical capacity of the zinc anode. Regarding electrode selection, halogen cathodes (Cl, Br, and I) offer high theoretical storage capacity and abundant raw materials, while iodine is favored due to its high natural abundance (iodine content in the ocean reaches 55 μg / L). -1 Zinc-iodine batteries have attracted considerable attention among halogens, providing a rich source of raw materials for zinc-iodine batteries. Zinc-iodine batteries are gaining momentum in various battery systems, perfectly meeting the industrial requirements for balanced battery performance and offering the best cost-effectiveness among all zinc-ion battery types. They meet performance and stability requirements while also showing promising prospects, making them the best choice for the next stage of industrial development. Despite their many advantages, zinc-iodine batteries still face some technical challenges that limit their large-scale application. Aqueous zinc-iodine batteries face problems such as polyiodide shuttle and slow iodine conversion kinetics, which limit their efficiency in practical applications. Polyiodide shuttle leads to the loss of active material, reacts with zinc ions at the zinc anode, and causes undesirable self-discharge reactions. Furthermore, polyiodide conversion cannot be directly converted to elemental iodine, resulting in slow redox energy storage kinetics. These problems reduce the battery's capacity and coulombic efficiency. Summary of the Invention
[0004] To address the above problems, this invention provides a method for preparing C@BiOI composite electrode material and its application in aqueous zinc-iodine batteries.
[0005] The technical solution adopted in this invention is:
[0006] A C@BiOI composite electrode material is prepared by the following steps: Bi(NO3)2 is dissolved in a mixed solution of ethanol and ethylene glycol, biomass carbon made from coconut shell is added, and after stirring at room temperature, a hydrothermal reaction is carried out. The mixture is then washed and dried to obtain a C@Bi2O3 composite material. The dried composite material is then subjected to solution adsorption to anchor the active substance iodine onto the composite material to obtain the C@BiOI composite electrode material.
[0007] Furthermore, in the above-mentioned method for preparing a C@BiOI composite electrode material, the molar ratio of C:BiOI is 20:1.
[0008] Furthermore, in the above-mentioned method for preparing a C@BiOI composite electrode material, the hydrothermal reaction is carried out in a Teflon-lined autoclave at 160°C for 6 hours.
[0009] Furthermore, in the above-mentioned method for preparing a C@BiOI composite electrode material, the solution adsorption method involves placing the C@Bi2O3 composite material in a 1M KI solution at room temperature and allowing it to stand for 6 hours.
[0010] The application of any of the above-mentioned C@BiOI composite electrode materials as positive electrodes in aqueous zinc-iodine batteries.
[0011] Furthermore, the above applications are implemented as follows:
[0012] 1) Preparation of negative electrode: A zinc sheet with a thickness of 0.1 mm and a purity of 99.99% is polished with sandpaper to remove the oxide layer on the surface. The polished zinc sheet is then cut into a circular negative electrode sheet with a diameter of 12 mm.
[0013] 2) Using a positive electrode coated with C@BiOI composite electrode material as the positive electrode and a negative electrode prepared in step 1) as the negative electrode, and the electrolyte being 1M zinc sulfate and 0.1M potassium iodide, an aqueous zinc-iodine battery is obtained.
[0014] Furthermore, in the above application, the preparation method of the positive electrode sheet coated with C@BiOI composite electrode material includes the following steps: after the C@BiOI composite electrode material is mixed evenly with binder and conductive material, a small amount of NMP is added as a solvent, and after mixing evenly, it is directly coated onto the substrate carbon paper, dried in a vacuum drying oven, and taken out to obtain the positive electrode sheet coated with C@BiOI composite electrode material.
[0015] Furthermore, in the above-mentioned method for preparing a positive electrode sheet coated with C@BiOI composite electrode material, the binder is PVDF.
[0016] Furthermore, in the above-mentioned method for preparing a positive electrode coated with C@BiOI composite electrode material, the conductive material is Super-p.
[0017] Furthermore, in the above-mentioned method for preparing a positive electrode sheet coated with C@BiOI composite electrode material, the mass ratio of C@BiOI composite electrode material: binder: conductive material is 8:1:1.
[0018] The beneficial effects of this invention are:
[0019] 1. By introducing bismuth oxide into the synthesis process, the reaction between bismuth oxide and iodide ions is introduced, effectively anchoring the iodide ions generated during the process.
[0020] 2. Bismuth oxide itself also has redox energy storage characteristics, which improves the specific capacity and rate performance of the material during charge and discharge processes.
[0021] 3. The electrode material of this invention has the characteristics of low cost, environmental friendliness and high safety.
[0022] 4. The electrode material of this invention has advantages such as high energy density and power density.
[0023] 5. The synthesis and assembly processes of this invention are simple, easy to operate and control, and suitable for continuous large-scale production.
[0024] 6. After modification, the capacity of the electrode material increased from the previous 170 mAh g. -1 Upgraded to 340mAh g -1 . Attached Figure Description
[0025] Figure 1 This is the XRD pattern of C@BiOI prepared in Example 1.
[0026] Figure 2 This is the SEM image of C@BiOI prepared in Example 1.
[0027] Figure 3 This is the cyclic voltammetry curve of C@BiOI prepared in Example 1.
[0028] Figure 4 This is a specific capacity diagram of C@BiOI prepared in Example 1. Detailed Implementation
[0029] The technical solution of the present invention will be further described below, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention shall be covered within the protection scope of the present invention.
[0030] Example 1
[0031] (I) The preparation method of C@BiOI is as follows:
[0032] 0.97 g Bi(NO3)2 was dissolved in 34 mL of ethanol and 17 mL of ethylene glycol. After stirring at room temperature for 1 hour, 0.48 g of biomass charcoal made from coconut shells was added. The mixture was transferred to a 50 mL Teflon-lined autoclave and stored at 160 °C for 6 hours. The product was washed several times with deionized water and ethanol and dried in a vacuum oven at 80 °C for 12 hours to obtain the C@Bi2O3 composite material. The C@Bi2O3 composite material powder obtained in the above experiment was dissolved in 50 mL of 1 M KI and allowed to stand for 6 hours to anchor the active substance iodine on the composite material, thus obtaining the C@BiOI composite electrode material (ACBI).
[0033] (II) Comparative Example
[0034] Pure biochar (AC): Biochar made from coconut shells was purchased from Kuraray Corporation.
[0035] (III) Testing
[0036] Figure 1 This is the XRD pattern of C@BiOI prepared in this embodiment. Figure 1 As can be seen, the XRD pattern of the sample is basically consistent with the standard pattern of BiOI, with the carbon peak at 27°. Figure 2 This is the SEM image of C@BiOI. (Source: [Insert Source Here]) Figure 2 It is evident that the prepared C@BiOI exhibits a typical sheet-like structure. Figure 3 This is the cyclic voltammetry curve of C@BiOI. (From...) Figure 3 It is evident that the area enclosed by C@BiOI is significantly larger than that of pure biomass carbon, indicating that the capacity of C@BiOI is greater than that of pure biomass carbon. Figure 4 This is a specific capacity diagram of pure biomass carbon and C@BiOI. (From...) Figure 4 It is evident that the specific capacity and cycle stability of C@BiOI are far superior to those of pure biomass carbon.
[0037] Example 2: Preparation of C@BiOI
[0038] 0.97 g Bi(NO3)2 was dissolved in 34 mL of ethanol and 17 mL of ethylene glycol. After stirring at room temperature for 1 hour, 0.24 g of biomass charcoal made from coconut shells was added. The mixture was then transferred to a 50 mL Teflon-lined autoclave and stored at 160 °C for 6 hours. The product was washed several times with deionized water and ethanol and dried in a vacuum oven at 80 °C for 12 hours to obtain the C@Bi2O3 composite material. The C@Bi2O3 composite material powder obtained in the above experiment was dissolved in 50 mL of 1 M KI and allowed to stand for 6 hours to anchor the active substance iodine onto the composite material, thus obtaining the C@BiOI composite electrode material (ACBI).
[0039] Example 3: Preparation of C@BiOI
[0040] 0.97 g Bi(NO3)2 was dissolved in 34 mL of ethanol and 17 mL of ethylene glycol. After stirring at room temperature for 1 hour, 0.12 g of biomass charcoal made from coconut shells was added. The mixture was then transferred to a 50 mL Teflon-lined autoclave and stored at 160 °C for 6 hours. The product was washed several times with deionized water and ethanol and dried in a vacuum oven at 80 °C for 12 hours to obtain the C@Bi2O3 composite material. The C@Bi2O3 composite material powder obtained in the above experiment was dissolved in 50 mL of 1 M KI and allowed to stand for 6 hours to anchor the active substance iodine onto the composite material, thus obtaining the C@BiOI composite electrode material (ACBI).
[0041] Example 4: Preparation of C@BiOI
[0042] 0.97 g Bi(NO3)2 was dissolved in 34 mL of ethanol and 17 mL of ethylene glycol. After stirring at room temperature for 1 hour, 0.96 g of biomass charcoal made from coconut shells was added. The mixture was transferred to a 50 mL Teflon-lined autoclave and stored at 160 °C for 6 hours. The product was washed several times with deionized water and ethanol and dried in a vacuum oven at 80 °C for 12 hours to obtain the C@Bi2O3 composite material. The C@Bi2O3 composite material powder obtained in the above experiment was dissolved in 50 mL of 1 M KI and allowed to stand for 6 hours to anchor the active substance iodine on the composite material, thus obtaining the C@BiOI composite electrode material (ACBI).
[0043] Example 5: Preparation of Anode Material
[0044] The zinc sheet with a thickness of 0.1 mm and a purity of 99.99% was repeatedly sanded to remove the oxide layer on the surface. The sanded zinc sheet was then cut into a circular negative electrode sheet with a diameter of 12 mm for later use.
[0045] Example 6: Preparation of an aqueous zinc-iodine battery
[0046] 1) Preparation of positive electrode: The C@BiOI composite electrode material prepared in Example 1 was mixed with PVDF and Super-p (in a mass ratio of 8:1:1) and a small amount of NMP was added as a solvent. After mixing evenly, the mixture was directly coated onto the substrate carbon paper, dried in a vacuum drying oven, and then removed to obtain a positive electrode sheet coated with C@BiOI composite electrode material.
[0047] 2) Using the positive electrode sheet prepared in step 1) as the positive electrode and the negative electrode sheet prepared in Example 5 as the negative electrode, an aqueous zinc-iodine battery was obtained by selecting 1M zinc sulfate and 0.1M potassium iodide as the electrolyte and electrochemical tests were performed.
[0048] Example 7: Preparation of an aqueous zinc-iodine battery
[0049] 1) Preparation of positive electrode: The C@BiOI composite electrode material prepared in Example 2 was mixed with PVDF and Super-p (in a mass ratio of 8:1:1) and a small amount of NMP was added as a solvent. After mixing evenly, the mixture was directly coated onto the substrate carbon paper, dried in a vacuum drying oven, and then removed to obtain a positive electrode sheet coated with C@BiOI composite electrode material.
[0050] 2) Using the positive electrode sheet prepared in step 1) as the positive electrode and the negative electrode sheet prepared in Example 5 as the negative electrode, an aqueous zinc-iodine battery was obtained by selecting 1M zinc sulfate and 0.1M potassium iodide as the electrolyte and electrochemical tests were performed.
[0051] Example 8: Preparation of an aqueous zinc-iodine battery
[0052] 1) Preparation of positive electrode: The C@BiOI composite electrode material prepared in Example 3 was mixed with PVDF and Super-p (in a mass ratio of 8:1:1) and a small amount of NMP was added as a solvent. After mixing evenly, the mixture was directly coated onto the substrate carbon paper, dried in a vacuum drying oven, and then removed to obtain a positive electrode sheet coated with C@BiOI composite electrode material.
[0053] 2) Using the positive electrode sheet prepared in step 1) as the positive electrode and the negative electrode sheet prepared in Example 5 as the negative electrode, an aqueous zinc-iodine battery was obtained by selecting 1M zinc sulfate and 0.1M potassium iodide as the electrolyte and electrochemical tests were performed.
[0054] Example 9: Preparation of an aqueous zinc-iodine battery
[0055] 1) Preparation of positive electrode: The C@BiOI composite electrode material prepared in Example 4 was mixed with PVDF and Super-p (in a mass ratio of 8:1:1) and a small amount of NMP was added as a solvent. After mixing evenly, the mixture was directly coated onto the substrate carbon paper, dried in a vacuum drying oven, and then removed to obtain a positive electrode sheet coated with C@BiOI composite electrode material.
[0056] 2) Using the positive electrode sheet prepared in step 1) as the positive electrode and the negative electrode sheet prepared in Example 5 as the negative electrode, an aqueous zinc-iodine battery was obtained by selecting 1M zinc sulfate and 0.1M potassium iodide as the electrolyte and electrochemical tests were performed.
[0057] Of the four aqueous zinc-iodine ion batteries assembled according to Examples 6-9 above, Example 6 showed the best electrochemical performance at a current density of 3 Ag. -1 The cycle life reaches 1000 cycles, with a capacity retention rate of 86.39% (e.g., Figure 4 As shown in Example 6, when C:BiOI = 20:1, the BiOI deposited on carbon is more uniform and ordered, resulting in more and more uniform iodine ion adsorption sites on carbon. This has a more favorable effect on the separation of elemental iodine and iodine ions, thereby improving its electrochemical performance.
Claims
1. The application of a C@BiOI composite electrode material as a positive electrode in an aqueous zinc-iodine battery, characterized in that, The preparation method of the C@BiOI composite electrode material includes the following steps: dissolving Bi(NO3)2 in a mixed solution of ethanol and ethylene glycol, adding biomass carbon made from coconut shells, stirring at room temperature, carrying out a hydrothermal reaction, washing, drying, and obtaining C@Bi2O3 composite material; anchoring the active substance iodine on the dried composite material by solution adsorption to obtain C@BiOI composite electrode material. The solution adsorption method involves placing the C@Bi2O3 composite material in a 1 M KI solution at room temperature and allowing it to stand for 6 hours.
2. The application according to claim 1, characterized in that, In the C@BiOI composite electrode material, the molar ratio of C:BiOI is 20:
1.
3. The application according to claim 1, characterized in that, The hydrothermal reaction was carried out in a Teflon-lined autoclave at 160°C for 6 hours.
4. The application according to claim 1, characterized in that, The method is as follows: 1) Preparation of negative electrode: A zinc sheet with a thickness of 0.1 mm and a purity of 99.99% is polished with sandpaper to remove the oxide layer on the surface. The polished zinc sheet is then cut into a circular negative electrode sheet with a diameter of 12 mm. 2) Using a positive electrode sheet coated with C@BiOI composite electrode material as the positive electrode and a negative electrode sheet prepared in step 1) as the negative electrode, and the electrolyte being 1 M zinc sulfate and 0.1 M potassium iodide, an aqueous zinc-iodine battery is obtained.
5. The application according to claim 4, characterized in that, The preparation method of the positive electrode sheet coated with C@BiOI composite electrode material includes the following steps: after the C@BiOI composite electrode material is mixed evenly with binder and conductive material, a small amount of NMP is added as a solvent, and after mixing evenly, it is directly coated onto the substrate carbon paper, dried in a vacuum drying oven, and taken out to obtain the positive electrode sheet coated with C@BiOI composite electrode material.
6. The application according to claim 5, characterized in that, The adhesive is PVDF.
7. The application according to claim 5, characterized in that, The conductive material is Super-p.
8. The application according to claim 5, characterized in that, By mass ratio, the ratio of C@BiOI composite electrode material to binder to conductive material is 8:1:1.