Modified glass fiber membrane, preparation method and application thereof, and zinc-iodine battery
By bonding halogen-containing polymers to the surface of a glass fiber membrane substrate, the electrostatic repulsion effect is used to restrict iodide ions on the positive electrode surface, thus solving the problem of iodide shuttle effect and improving the cycle stability and specific capacity retention of zinc-iodine batteries.
Patent Information
- Application Number
- CN202511259019.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-04
- Publication Date
- 2025-12-23
AI Technical Summary
The iodide shuttle effect leads to the loss of active material in the positive electrode and corrosion of the zinc negative electrode in zinc-iodine batteries, reducing cycle life and coulombic efficiency, which has become the core bottleneck in the development of zinc-iodine batteries.
Modified glass fiber membranes are used, and halogen-containing polymers such as brominated polystyrene, polyvinylidene fluoride, polybrominated polyethylene, and polyvinylidene fluoride are bonded to the surface of the glass fiber membrane matrix. The high electronegativity of halogen atoms attracts electrons, making the membrane surface rich in negative charges. The electrostatic repulsion effect restricts iodine ions on the positive electrode surface and inhibits their shuttle.
It effectively suppresses the shuttle effect of iodine ions, improves the cycle stability and specific capacity retention of zinc-iodine batteries, and extends battery life.
Smart Images
Figure CN121192369A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of zinc-iodine battery technology, specifically relating to a modified glass fiber membrane, its preparation method and application, and zinc-iodine batteries. Background Technology
[0002] In the field of aqueous energy storage system research, aqueous battery technology based on mild electrolytes has made significant progress in recent years. These batteries, with their inherent safety, environmental friendliness, low cost, and simple manufacturing process, show broad application prospects in consumer electronics and flexible wearable devices. Among them, metallic zinc stands out for its outstanding comprehensive performance (theoretical capacity 820 mAh·g). -1 / 5855mAh·cm -3 With its low redox potential of -0.76V vs. SHE, excellent compatibility and stability with aqueous electrolytes, and abundant natural resources, it has become one of the most promising anode materials for aqueous batteries.
[0003] After more than a decade of research and accumulation, the cathode material system for aqueous zinc-ion batteries has formed five main categories: vanadium-based compounds, manganese-based compounds, organic compounds, transition metal sulfides, and other novel materials (such as iodine-based cathode materials). Iodine-based cathode materials are attracting significant attention from the academic community due to their unique advantages: firstly, the natural abundance of iodine in seawater reaches 50–60 μg·L⁻¹. -1 Firstly, it possesses significant resource advantages; secondly, the multivalent state characteristics of iodine (-1, 0, +1, +3, +5, and +7) endow it with multi-electron transfer potential, corresponding to a theoretical capacity of up to 422 mAh·g. -1 (based on I) - →I 0 →I + (Transformation); Third, the iodine-based system exhibits a higher theoretical output voltage. However, iodine exhibits an iodide shuttle effect, which not only leads to the continuous loss of positive electrode active material but also causes zinc negative electrode corrosion, exacerbates battery self-discharge, and reduces cycle life and coulombic efficiency, becoming a core bottleneck restricting the development of zinc-iodine batteries. Summary of the Invention
[0004] The purpose of this invention is to provide a modified glass fiber membrane, its preparation method and application, and zinc-iodine batteries. The modified glass fiber membrane provided by this invention, when applied to the separator of zinc-iodine batteries, can effectively suppress the iodide shuttle effect.
[0005] To achieve the objectives of this invention, the following technical solutions are provided:
[0006] A modified glass fiber membrane includes a glass fiber membrane matrix and a halogen-containing polymer bonded to the surface of the glass fiber matrix by an adhesive.
[0007] Preferably, the halogen in the halogen-containing polymer includes one or more of fluorine, chlorine, and bromine.
[0008] Preferably, the halogen-containing polymer is one or more of brominated polystyrene, polyvinylidene fluoride, polybrominated polyethylene, and polyvinylidene fluoride.
[0009] Preferably, the adhesive comprises one or more of polyvinylidene fluoride, sodium carboxymethyl cellulose, styrene-butadiene rubber, and polyvinyl alcohol.
[0010] Preferably, the mass ratio of the halogen-containing polymer to the binder is 2-30:0.1-2;
[0011] The mass of the halogen polymer per unit area of the glass fiber matrix is 0.1–3 mg.
[0012] The present invention also provides a method for preparing the modified glass fiber membrane described in the above technical solution, comprising the following steps:
[0013] A modified liquid is obtained by mixing a halogen-containing polymer, a binder, and a solvent.
[0014] The glass fiber membrane substrate is immersed in the modified liquid and dried to obtain the modified glass fiber membrane.
[0015] Preferably, the soaking time is 2 to 12 hours.
[0016] Preferably, the drying temperature is 60–120°C and the drying time is 6–12 hours.
[0017] The present invention also provides the application of the modified glass fiber membrane described in the above technical solution or the modified glass fiber membrane prepared by the preparation method described in the above technical solution in zinc-iodine battery separators.
[0018] The present invention also provides a zinc-iodine battery, comprising a positive electrode, a negative electrode, an electrolyte, and a separator, wherein the separator is the modified glass fiber membrane described in the above technical solution or the modified glass fiber membrane prepared by the preparation method described in the above technical solution.
[0019] This invention provides a modified glass fiber membrane, comprising a glass fiber membrane matrix and a halogen-containing polymer bonded to the surface of the glass fiber matrix by an adhesive. This invention uses a halogen-containing polymer as the glass fiber modifying material. The modified glass fiber membrane retains its original fibrous structure, with only the halogen-containing polymer physically attached or adhered to the surface compared to unmodified glass fibers. Specifically, the halogen atoms in the halogen-containing polymer are highly electronegative elements, strongly attracting electrons in the polymer chain, causing electron cloud shift and enriching the surface of the glass fiber membrane matrix with negative charges. By adhering the negatively charged halogen-containing polymer to the glass fiber surface to modify the glass fiber membrane, when assembled into a battery, due to electrostatic repulsion, iodine ions (I₂O₃) on the positive electrode side... - / I 3- The iodine ions are confined to the positive electrode surface, limiting their shuttle movement. Example results show that the modified glass fiber membrane provided by this invention, when assembled into an H-type electrolytic cell, did not experience iodine ion penetration even after 1 hour of immersion; when used as a separator material for zinc-iodine batteries, it exhibits good performance at 10 mA cm⁻¹. -1 At the specified current density, the specific capacity remained at 0.38 mAh cm⁻¹ after 6000 cycles. -2 The capacity retention rate was 93.7%, proving that the modified glass fiber membrane provided by the present invention effectively inhibits the shuttle of iodine ions and improves the cycle stability of zinc-iodine batteries. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 Here is a SEM image of the PVDF-modified glass fiber membrane obtained in Example 1;
[0022] Figure 2 The image shows the EDS spectrum of the PVDF-modified glass fiber membrane obtained in Example 1.
[0023] Figure 3 A digital photograph of the H-type electrolytic cell assembled with the PVDF-modified glass fiber membrane in Application Example 1;
[0024] Figure 4 The cycling curve of the zinc-iodine battery prepared using the PVDF-modified glass fiber membrane in Example 2 is shown.
[0025] Figure 5 Here is a SEM image of the BPS-modified glass fiber membrane obtained in Example 2;
[0026] Figure 6 The EDS spectrum of the BPS-modified glass fiber membrane obtained in Example 2 is shown below.
[0027] Figure 7 A digital photograph of the H-type electrolytic cell assembled with the BPS-modified glass fiber membrane in Application Example 3;
[0028] Figure 8 The cycling curve of the zinc-iodine battery prepared using the BPS-modified glass fiber membrane in Example 4 is shown.
[0029] Figure 9 SEM images of commercially available glass fiber membranes are provided for comparison.
[0030] Figure 10 EDS spectra of a commercially available glass fiber membrane for comparison;
[0031] Figure 11 For comparison, a digital photograph of the H-type electrolyzer assembled with a commercial glass fiber membrane in Application Example 1;
[0032] Figure 12 The cycling curves of zinc-iodine batteries prepared using commercial glass fiber membranes in Application Example 2 are shown for comparison. Detailed Implementation
[0033] The present invention provides a modified glass fiber membrane, comprising a glass fiber membrane matrix and a halogen-containing polymer bonded to the surface of the glass fiber matrix by an adhesive.
[0034] In this invention, unless otherwise specified, all raw materials used in the preparation are commercially available products well known to those skilled in the art.
[0035] In this invention, the halogen-containing polymer can be halogen-containing polyethylene; the halogen includes one or more of fluorine, chlorine, and bromine; the halogen-containing polymer is one or more of brominated polystyrene (BPS), polyvinylidene fluoride (PVF), polybrominated polyethylene (PVB), and polyvinylidene fluoride (PVDF), and in specific embodiments it can be BPS or PVDF. In this invention, if the halogen-containing polymer itself has adhesive properties, no additional binder, such as PVDF, is added. The halogen atoms in the halogen-containing polymer in this invention have extremely high electronegativity, which strongly attracts electrons in the polymer chain of the polymer material, causing electron cloud shift and enriching the material surface with negative charges. When the halogen-containing polymer is adhered to modified glass fiber and assembled into a battery, due to electrostatic repulsion, iodine ions on the positive electrode side are confined to the positive electrode surface, effectively limiting the shuttle movement of iodine ions.
[0036] In this invention, the binder includes one or more of polyvinylidene fluoride, sodium carboxymethyl cellulose, styrene-butadiene rubber, and polyvinyl alcohol; the binder should be selected according to the different solvents, such as PVDF is suitable for NMP, DMF, and ethanol, CMC is suitable for deionized water, PVA is suitable for deionized water, etc.
[0037] In this invention, the mass ratio of the halogenated polymer to the binder is 2-30:0.1-2; the mass of the halogenated polymer per unit area of the glass fiber matrix is 0.1-3 mg, and in specific embodiments, it can be 0.3, 0.5, 1.1, 1.7, 1.9, 2.3, or 2.8 mg. This invention controls the loading of the halogenated polymer within the above range to prevent uneven adhesion due to excessively low loading and blockage of glass fiber channels due to excessively high loading, which affects ion migration. Furthermore, the low-loading halogenated polymer of this invention exhibits high iodine ion shuttle inhibition performance under low loading conditions. Compared to negatively charged materials such as metal oxides and MOF materials, this invention has the advantage of low cost. The addition of the binder in this invention is mainly to ensure stable adhesion of the halogenated polymer to the glass fiber surface; insufficient binder will lead to detachment of the halogenated polymer, while excessive addition will affect the effect of inhibiting iodine ion migration. Therefore, it is necessary to control the amount of binder within the above range.
[0038] The present invention also provides a method for preparing the modified glass fiber membrane described in the above technical solution, comprising the following steps:
[0039] A modified liquid is obtained by mixing a halogen-containing polymer, a binder, and a solvent.
[0040] The glass fiber matrix is immersed in the modified liquid and dried to obtain the modified glass fiber membrane.
[0041] In this invention, the solvent includes water and / or organic solvents; in specific embodiments, it can be common organic solvents such as deionized water, anhydrous ethanol, N-methylpyrrolidone (NMP) and N,N-dimethylformamide (DMF).
[0042] In this invention, the concentration of the halogenated polymer in the modified liquid is 2–30 g·L. -1 In specific embodiments, the concentration can be 6, 10, 12, 18, 24, or 28 g·L. -1 The concentration of the adhesive is 0.1–2 g·L⁻¹. -1 In specific embodiments, the concentration can be 0.5, 0.7, 1.0, 1.3, or 1.8 g·L. -1 .
[0043] In this invention, the impregnation is carried out at room temperature; the impregnation time is 2–12 hours, and in specific embodiments it can be 4, 6, or 10 hours. Sufficient impregnation in this invention allows halogen-containing polymers to adhere better to the glass fiber surface.
[0044] In this invention, the drying temperature is 60–120°C, and in specific embodiments it can be 80 or 100°C, for a time of 6–12 hours, and in specific embodiments it can be 10 hours. This invention removes solvent and / or insoluble solvent by drying to obtain a halogen-containing polymer.
[0045] The present invention also provides the application of the modified glass fiber membrane described in the above technical solution or the modified glass fiber membrane prepared by the preparation method described in the above technical solution in zinc-iodine battery separators.
[0046] In this invention, the modified glass fiber membrane is applied to the negative electrode separator of a zinc-iodine battery. This invention does not impose any special limitations on the application method of the modified glass fiber membrane in zinc-iodine batteries; any application method of glass fiber membrane as a separator material for zinc-iodine batteries that is well known to those skilled in the art can be used.
[0047] This invention also provides a zinc-iodine battery, comprising a positive electrode, a negative electrode, an electrolyte, and a separator, wherein the separator is the modified glass fiber membrane described in the above-described technical solution or a modified glass fiber membrane prepared by the preparation method described in the above-described technical solution. This invention does not impose any particular limitations on the positive electrode, negative electrode, and electrolyte; materials well known to those skilled in the art can be used.
[0048] To further illustrate the present invention, the modified glass fiber separator, its preparation method and application, and zinc-iodine batteries provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments. However, these descriptions should not be construed as limiting the scope of protection of the present invention.
[0049] Example 1
[0050] Weigh 100 mg of PVDF powder, add 10 mL of NMP solution, stir until PVDF is completely dissolved, pour the resulting solution into a 6 cm diameter petri dish, cut glass fiber into 5 cm diameter discs and immerse them in the resulting solution for 10 h, then remove them and place them in a vacuum oven to dry at 90 °C for 8 h to obtain PVDF modified glass fiber membrane.
[0051] The PVDF-modified glass fiber membrane prepared in Example 1 was tested using a scanning electron microscope. The obtained SEM and EDS spectra are shown below. Figure 1 , Figure 2As shown in the SEM image, the PVDF-modified glass fiber still retains its original fibrous structure. The EDS results show that PVDF is uniformly adhered to the fiber surface, and the uniform distribution of F element on the surface indicates that PVDF is evenly distributed on the fiber surface.
[0052] Application Example 1
[0053] The PVDF-modified glass fiber membrane obtained in Example 1 was assembled into an H-type electrolytic cell, with deionized water and polyiodide ion solution added to both sides of the electrolytic cell.
[0054] The H-type electrolytic cell was observed using a digital camera at different times, and the resulting digital photographs are as follows: Figure 3 As shown, during the 1-hour settling period, iodine ions did not permeate through the glass fiber membrane to the other side, indicating that PVDF effectively inhibited the shuttle of polyiodine ions.
[0055] Application Example 2
[0056] Iodine-loaded activated carbon and Ketjen black (80 mg and 10 mg respectively) were thoroughly ground and mixed with PVDF at a mass ratio of 8:1:1. The mixture was homogenized in a homogenizer to form a slurry, which was then evenly coated onto current collector carbon paper. After drying, the slurry was cut into 8×8 mm electrode sheets and dried under vacuum at 60°C for 10 hours. A zinc-iodine battery was constructed using a zinc sheet as the counter electrode, the PVDF-modified glass fiber membrane prepared in Example 1 as the separator, and 2M ZnSO4 as the electrolyte.
[0057] Test Example 1
[0058] The zinc-iodine battery prepared for use case 2 was subjected to charge-discharge performance testing under the following conditions: constant current charge-discharge mode; current density of 10 mA cm⁻¹. -2 The discharge cutoff voltage is 0.6V, and the charging cutoff voltage is 1.6V.
[0059] The cycle performance of the zinc-iodine battery prepared in accordance with Example 2 was tested under the following conditions: constant current charging mode and current density of 10 mA cm⁻¹. -2 The discharge cutoff voltage is 0.6V, and the charging cutoff voltage is 1.6V.
[0060] The cycle curve of the zinc-iodine battery prepared in Example 2 is shown in the figure below. Figure 4 As shown in the figure, the specific capacity of the zinc-iodine battery prepared in Example 2 after 5000 cycles is 0.45 mAh cm⁻¹. -2 The capacity retention rate was 92.2%, indicating that the material has good cycle stability.
[0061] Example 2
[0062] Weigh 90 mg of BPS powder and 10 mg of PVDF powder, add 10 mL of NMP solution, and stir until BPS and PVDF are completely dissolved. Pour the resulting solution into a 6 cm diameter petri dish, cut glass fibers into 5 cm diameter discs and immerse them in the resulting solution for 10 h. Then remove them and place them in a vacuum oven to dry at 90 °C for 8 h to obtain a BPS / PVDF modified glass fiber membrane.
[0063] The BPS / PVDF modified glass fiber membrane prepared in Example 2 was tested using a scanning electron microscope. The obtained SEM and EDS spectra are shown below. Figure 5 , Figure 6 As shown in the SEM image, the BPS-modified glass fibers still retain their original fibrous structure. EDS results show that BPS is uniformly adhered to the fiber surface. l The uniform distribution of elements on the surface indicates that BPS is evenly distributed on the fiber surface.
[0064] Application Example 3
[0065] The BPS / PVDF modified glass fiber membrane prepared in Example 2 was assembled into an H-type electrolytic cell, with deionized water and polyiodide ion solution added to both sides of the electrolytic cell.
[0066] The H-type electrolytic cell was observed using a digital camera at different times, and the resulting digital photographs are as follows: Figure 7 As shown, during the 1-hour settling process, polyiodide ions did not permeate through the glass fiber membrane to the other side, indicating that the BPS-modified glass fiber membrane effectively inhibited the shuttle of polyiodide ions.
[0067] Application Example 4
[0068] Iodine-loaded activated carbon and Ketjen black (80 mg and 10 mg respectively) were thoroughly ground and mixed with PVDF at a mass ratio of 8:1:1. The mixture was homogenized in a homogenizer to form a slurry, which was then evenly coated onto current collector carbon paper. After drying, the slurry was cut into 8×8 mm electrode sheets and dried under vacuum at 60°C for 10 hours. A zinc-iodine battery was constructed using a zinc sheet as the counter electrode, the BPS / PVDF modified glass fiber membrane prepared in Example 2 as the separator, and 2M ZnSO4 as the electrolyte.
[0069] Test Example 2
[0070] The zinc-iodine battery prepared for use case 4 was subjected to charge-discharge performance testing. The test conditions were: constant current charge-discharge mode; current density of 10 mA cm⁻¹. -2 The discharge cutoff voltage is 0.6V, and the charging cutoff voltage is 1.6V.
[0071] The cycle performance of the zinc-iodine battery prepared in accordance with Example 4 was tested under the following conditions: constant current charging mode and current density of 10 mA cm⁻¹. -2 The discharge cutoff voltage is 0.6V, and the charging cutoff voltage is 1.6V.
[0072] The cycling curve of the zinc-iodine battery prepared in Example 4 is shown in the figure. Figure 8 As shown in the figure, the specific capacity of the battery prepared in Example 4 after 6000 cycles is 0.38 mAh cm⁻¹. -2 The capacity retention rate was 93.7%, indicating that the material has good cycle stability.
[0073] Comparative Application Example 1
[0074] Commercial glass fibers were tested using a scanning electron microscope, and the obtained SEM and EDS spectra are shown below. Figure 9 , Figure 10 As shown in the SEM image, commercially available glass fibers exhibit a fibrous structure.
[0075] Commercially available glass fibers are assembled into an H-type electrolytic cell, with deionized water and polyiodide ion solution added to both sides of the electrolytic cell.
[0076] The H-type electrolytic cell was observed using a digital camera at different times, and the resulting digital photographs are as follows: Figure 11 As shown, after standing for 30 minutes, polyiodide ions permeate through the glass fiber membrane to the other side, and polyiodide ion shuttle occurs.
[0077] Comparative Application Example 2
[0078] Iodine-loaded activated carbon and Ketjen black (80 mg and 10 mg respectively) were thoroughly ground and mixed with PVDF at a mass ratio of 8:1:1. The mixture was homogenized in a homogenizer to form a slurry, which was then evenly coated onto current collector carbon paper. After drying, the slurry was cut into 8×8 mm electrode sheets and dried under vacuum at 60°C for 10 hours. A zinc-iodine battery was then encapsulated using a zinc sheet as the counter electrode, commercially available glass fiber as the separator, and 2M ZnSO4 as the electrolyte.
[0079] Test Example 3
[0080] The charge-discharge performance of the zinc-iodine battery prepared in Comparative Application Example 2 was tested under the following conditions: constant current charge-discharge mode; current density of 10 mA cm⁻¹. -2 The discharge cutoff voltage is 0.6V, and the charging cutoff voltage is 1.6V.
[0081] Comparatively, the zinc-iodine battery prepared in Example 2 underwent cycle performance testing under the following conditions: constant current charging mode and current density of 10 mA cm⁻¹. -2 The discharge cutoff voltage is 0.6V, and the charging cutoff voltage is 1.6V.
[0082] The cycling curves of the battery prepared in Example 1 are shown in the figure below. Figure 12 As shown in the figure, the specific capacity of the battery prepared in Comparative Application Example 1 fluctuates drastically after 450 cycles, indicating that the iodine ions undergo a shuttle effect.
[0083] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.
Claims
1. A modified glass fiber membrane, characterized in that, It includes a glass fiber membrane matrix and a halogen-containing polymer bonded to the surface of the glass fiber matrix by an adhesive.
2. The modified glass fiber membrane according to claim 1, characterized in that, The halogens in the halogen-containing polymer include one or more of fluorine, chlorine, and bromine.
3. The modified glass fiber membrane according to claim 2, characterized in that, The halogen-containing polymer is one or more of brominated polystyrene, polyvinylidene fluoride, polybrominated polyethylene, and polyvinylidene fluoride.
4. The modified glass fiber membrane according to claim 1, characterized in that, The adhesive includes one or more of polyvinylidene fluoride, sodium carboxymethyl cellulose, styrene-butadiene rubber, and polyvinyl alcohol.
5. The modified glass fiber membrane according to claim 1, characterized in that, The mass ratio of the halogen-containing polymer to the binder is 2–30:0.1–2; The mass of the halogen polymer per unit area of the glass fiber matrix is 0.1–3 mg.
6. The method for preparing the modified glass fiber membrane according to any one of claims 1 to 5, characterized in that, Includes the following steps: A modified liquid is obtained by mixing a halogen-containing polymer, a binder, and a solvent. The glass fiber membrane substrate is immersed in the modified liquid and dried to obtain the modified glass fiber membrane.
7. The preparation method according to claim 6, characterized in that, The soaking time is 2 to 12 hours.
8. The preparation method according to claim 6, characterized in that, The drying temperature is 60–120°C, and the time is 6–12 hours.
9. The application of the modified glass fiber membrane according to any one of claims 1 to 5 or the modified glass fiber membrane prepared by the preparation method according to any one of claims 6 to 8 in zinc-iodine battery separators.
10. A zinc-iodine battery, comprising a positive electrode, a negative electrode, an electrolyte, and a separator, characterized in that, The diaphragm is the modified glass fiber membrane according to any one of claims 1 to 5 or the modified glass fiber membrane prepared by the preparation method according to any one of claims 6 to 8.