Magnetron ion sieving proton exchange membrane, method of making and use in a vanadium redox flow battery

Abstract

The application belongs to the technical field of magnetic control ion sieving proton exchange membrane, and particularly relates to a magnetic control ion sieving proton exchange membrane, a preparation method thereof and application thereof in a full vanadium redox flow battery. Specifically, the proton exchange membrane comprises a perfluorosulfonic acid resin matrix and a vertical magnetic anisotropy CoPd multilayer nanowire array deposited on the surface of the matrix, the nanowire diameter is 15-25 nm, and the nanowire spacing is 80-120 nm; during use of the proton exchange membrane, a spiral electromagnetic field gradient is generated by applying an axial magnetic field, and dynamic sieving of vanadium ions and hydrogen ions is realized by using Lorentz force, wherein the motion trajectory of the vanadium ions is selectively deflected, and the hydrogen ions remain linear transmission, thereby breaking through the selective-conductivity trade-off limitation of traditional membrane materials.

Description

Technical Field

[0001] This invention belongs to the field of magnetically controlled ion sieving proton exchange membrane technology, specifically relating to a magnetically controlled ion sieving proton exchange membrane, its preparation method, and its application in a vanadium redox flow battery. Background Technology

[0002] As one of the most promising large-scale energy storage technologies, the performance of vanadium redox flow batteries is closely related to the performance of their core component, the proton exchange membrane (PEM). The PEM plays a crucial role in vanadium redox flow batteries by conducting protons and blocking vanadium ion cross-linking; its performance directly affects the battery's energy efficiency, cycle life, and cost-effectiveness.

[0003] Currently, in commercial applications, the Nafion series perfluorosulfonic acid membranes produced by DuPont are widely used due to their excellent chemical stability and proton conductivity (0.08-0.15 S / cm). However, Nafion membranes have two key drawbacks: (1) excessively high vanadium ion permeability (approximately 10⁻⁶ cm⁻¹). 2 (2) High cost (approximately US$300-500 / m³), resulting in severe battery self-discharge and decreased coulombic efficiency; 2 This limits its large-scale application in large-scale energy storage power stations.

[0004] The main bottlenecks faced by existing technologies include: traditional modification methods struggle to overcome the trade-off between selectivity and conductivity, especially when vanadium permeability decreases to 10%. -8 cm 2 At the level of / s, proton conductivity often decreases simultaneously. To resolve this fundamental contradiction, academia and industry have been committed to developing novel composite membrane materials in recent years. Among these efforts, introducing nanostructured materials into the membrane to construct composite membranes has become a recognized effective strategy.

[0005] Currently, nanostructure doping mainly proceeds in two directions: one is to disperse zero-dimensional nanoparticles or two-dimensional nanosheets in a polymer matrix, aiming to enhance proton transport pathways or construct physical barriers through the interfacial effects of nanomaterials. The other is to introduce one-dimensional nanomaterials, utilizing their anisotropic structure and high aspect ratio to construct fast proton channels that penetrate the membrane. Studies show that oriented carbon nanotubes, metal oxide nanowires, etc., can form continuous "proton highways," improving proton conductivity while, due to their regular nanopores, suppressing vanadium ion migration to a certain extent based on steric hindrance effects, thereby improving selectivity. However, existing nanocomposite membrane technologies have fundamental limitations: their function is essentially static, relying on fixed-size sieving and tortuous channels; once prepared, the performance is fixed and cannot respond to external conditions; at the same time, nanomaterials are mostly randomly dispersed within the membrane, making it difficult to achieve precise control of ion transport.

[0006] With the rapid growth of the global energy storage market, there is an increasing demand for high-performance and low-cost proton exchange membranes. In particular, in the application scenarios of wind and solar power generation with energy storage and grid frequency regulation, the proton exchange membrane needs to maintain high selectivity while having dynamic response capability to adapt to different working conditions. The existing technical routes cannot meet this demand, and innovative ion sieving technology is urgently needed. SUMMARY

[0007] To solve the problems in the prior art, the application provides a magnetic control ion sieving proton exchange membrane, a preparation method thereof and an application thereof in a full vanadium redox flow battery. A vertical magnetic anisotropy CoPd multilayer nanowire array is constructed on the surface of a perfluorosulfonic acid resin matrix, a spiral electromagnetic field gradient is generated by applying an axial magnetic field, and the selective deflection of vanadium ions is realized by using the Lorentz force, while maintaining the efficient transmission of protons, thereby breaking through the selectivity-conductivity trade-off limitation of traditional membrane materials.

[0008] The technical scheme of the application is as follows:

[0009] The application discloses a magnetic control ion sieving proton exchange membrane, which comprises a perfluorosulfonic acid resin matrix and a vertical magnetic anisotropy CoPd multilayer nanowire array deposited on the surface of the matrix, wherein the diameter of the nanowire is 15-25 nm, and the spacing between the nanowires is 80-120 nm.

[0010] During the use of the proton exchange membrane, a spiral electromagnetic field gradient is generated by applying an axial magnetic field, and the dynamic sieving of vanadium ions and hydrogen ions is realized by using the Lorentz force, wherein the motion trajectory of the vanadium ions is selectively deflected, and the hydrogen ions maintain linear transmission.

[0011] Further, the magnetic control ion sieving proton exchange membrane described above, the CoPd nanowire is a multilayer structure, which is formed by periodic repetition of [Co / Pd], and the repetition period is 40-60, and the nanowire has a vertical magnetic anisotropy characteristic.

[0012] Further, the magnetic control ion sieving proton exchange membrane described above, the top end of the nanowire is provided with an Al2O3 or SiO2 insulating layer with a thickness of 1-3 nm, which is used for preventing corrosion and reducing interface resistance.

[0013] Further, the magnetic control ion sieving proton exchange membrane described above, the strength of the axial magnetic field is 0.3-1.2 T, preferably 0.5-1.0 T.

[0014] Further, the magnetic control ion sieving proton exchange membrane described above, the proton conductivity of the proton exchange membrane is ≥0.15 S / cm, the vanadium ion permeability is ≤1×10 -8 cm 2 / s, and the selectivity ratio of hydrogen ions to vanadium ions is ≥1×107 .

[0015] Furthermore, in the aforementioned magnetron-controlled ion sieving proton exchange membrane, the thickness of the proton exchange membrane is 10-60 μm, preferably 20-40 μm; and the mechanical strength is ≥30 MPa.

[0016] This invention also discloses a method for preparing the aforementioned magnetron-controlled ion-sieving proton exchange membrane, comprising the following steps:

[0017] (1) Nanowire array templates are prepared on a substrate using electron beam lithography, nanoimprint lithography, interference lithography combined with reactive ion etching, or anodic oxidation.

[0018] (2) A CoPd multilayer nanowire array was prepared on the template by electrochemical atomic layer deposition;

[0019] (3) The nanowire array is transferred to the surface of the perfluorosulfonic acid resin matrix.

[0020] Furthermore, in the above-mentioned method for preparing a magnetron-controlled ion-sieve proton exchange membrane, the electrochemical deposition conditions in step (2) include: a deposition temperature of 75-85℃, a deposition potential of -0.7V to -0.9V relative to the Ag / AgCl reference electrode, and a deposition solution pH of 3.0-4.0.

[0021] Furthermore, in the above-mentioned method for preparing the magnetically controlled ion sieve proton exchange membrane, step (3) uses a hot pressing method for transfer, with a hot pressing temperature of 100-150℃, a pressure of 5-15 MPa, and a time of 10-30 min; or a roll pressing process is used for roll-to-roll production.

[0022] This invention also discloses the application of the above-mentioned magnetically controlled ion-sieving proton exchange membrane in a vanadium redox flow battery.

[0023] Advantages and beneficial effects of the present invention:

[0024] In terms of performance indicators, this invention achieves a proton conductivity of 0.15-0.18 S / cm (25℃) and 10 -9 cm 2 Vanadium permeability on the order of / s, with a selectivity exceeding 10. 8 This is two orders of magnitude better than commercial Nafion membranes;

[0025] This invention achieves real-time dynamic control of ion selectivity; by adjusting the magnetic field strength (0.3-1.2T), the selectivity ratio can be maintained within 10-1. 7 -10 8 Precisely adjustable within the range;

[0026] The preparation process is simplified by 30%, and cost estimation shows that the membrane material cost can be controlled at 200 dollars / m after scaling up 2 The following. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Structure and function schematic diagram of the magnetic control ion sieve proton exchange membrane of the present application;

[0028] Figure 2 Schematic diagram of CoPd multilayer nanowire array;

[0029] In the figure, 1 is a perfluorosulfonic acid resin matrix, 2 is a CoPd multilayer nanowire array, 3 is a force field repelled hydrated vanadium ion, 4 is a self-moving hydrogen ion; 5 is a CoPd multilayer nanowire; 6 is a repeating unit; 7 is a Co layer; 8 is a Pd layer. DETAILED DESCRIPTION

[0030] In the detailed description, as Figure 1 shown, the magnetic control ion sieve proton exchange membrane of the present application includes a perfluorosulfonic acid resin matrix 1 and a vertical magnetic anisotropy CoPd multilayer nanowire array 2 deposited on the surface of the matrix, and in use, by applying an axial magnetic field to generate a spiral electromagnetic field gradient, the dynamic screening of the force field repelled hydrated vanadium ion 3 and the self-moving hydrogen ion 4 is realized by using the Lorentz force; as Figure 2 shown, the CoPd multilayer nanowire array of the present application is composed of a CoPd multilayer nanowire 5, and the nanowire is composed of a plurality of repeating units 6, wherein each repeating unit is composed of a Co layer 7 and a Pd layer 8.

[0031] The present application is verified by examples, and exhibits the excellent performance and innovative value of the magnetic control ion sieve proton exchange membrane. In key performance, the example uses a 0.8 T axial continuous magnetic field, realizes a hydrogen / vanadium ion selectivity ratio of about 4.2×10 7 , and the proton conductivity reaches 0.22 S / cm; after introducing a pulsed magnetic field mode, the selectivity ratio can be improved to about 6.7×10 7 , and at the same time, the vanadium ion permeability is significantly reduced to 3.0×10 -9cm2 / s, which embodies the dynamic intelligent regulation advantage. The optimally designed CoPd multilayer nanowire array (diameter 20 nm, spacing 100 nm) combined with the top Al2O3 / SiO2 insulating layer ensures high proton conduction while endowing the membrane material with excellent mechanical strength (≥ 38 MPa) and chemical stability. The comparative experiment powerfully proves that the performance improvement of the present application is directly derived from the synergistic effect of "vertical ordered array" and "external magnetic field": under the condition of no magnetic field, the vanadium ion permeability increases sharply; the disordered composite structure cannot realize effective screening even under the magnetic field, highlighting the necessity and creativity of the structural design of the present application. In summary, the present application not only breaks through the "trade-off" limit of traditional proton exchange membranes in core performance, but also realizes the dynamic, reversible and high-selectivity screening of ions through the magnetic field, showing significant technical advancement and practical engineering prospect.

[0032] The specific embodiments of the present application will be further described in detail below in combination with the drawings and examples of the specification. It should be understood that the examples described herein are only used to explain the present application and do not limit the present application.

[0033] Example 1

[0034] The preparation method of the present embodiment comprises the following steps:

[0035] (1) Template preparation: an ordered nanopore array template is prepared on a silicon wafer subjected to surface oxidation by using electron beam lithography technology. The specific parameters are: pore diameter 15 nm, pore center distance 80 nm, and pore depth 1 μm;

[0036] (2) Nanowire array electrodeposition:

[0037] Preparation of deposition solution: 0.02M CoSO4, 0.01M Pd(NH3)2Cl2 and 0.5M H3BO3 are prepared, and the pH is adjusted to 3.0 with dilute H2SO4;

[0038] A three-electrode system (working electrode: template / silicon substrate, counter electrode: platinum sheet, reference electrode: Ag / AgCl) is used to carry out the deposition in a constant-temperature deposition tank at 75°C;

[0039] Double-pulse potential method is used for periodic deposition: first, Co is deposited at -0.7V for 0.5 seconds, and then Pd is deposited at -0.9V for 3 seconds, which is one [Co / Pd] cycle. This cycle is repeated 40 times, and after the deposition is completed, the deionized water is repeatedly washed;

[0040] (3) Insulating layer coating: the template with nanowire array is placed in an atomic layer deposition device, and trimethylaluminum and water are used as precursors to carry out cyclic reaction at 120°C to deposit a 1 nm thick Al2O3 layer;

[0041] (4) Array transfer and membrane compounding:

[0042] A 10 μm-thick perfluorosulfonic acid resin membrane was placed on a hot press;

[0043] The template obtained in step (3) (with the nanowires facing downward) was placed on the resin membrane in alignment;

[0044] The nanowires were embedded into the surface of the resin membrane by hot pressing at 100°C under a pressure of 5 MPa for 10 minutes;

[0045] After natural cooling, the silicon wafer substrate was peeled off, and the template was removed by etching with a 5 wt% NaOH solution, to finally obtain a proton exchange membrane with a thickness of 10 μm and a surface having a CoPd multilayer nanowire array.

[0046] Performance tests were conducted on the present example:

[0047] The prepared membrane was assembled in a vanadium redox flow battery single cell test cell, and the effective area of the membrane was 4 cm². The electrolyte was 1.5 M VOSO4 / 3.0 M H2SO4 (positive electrode) and 1.5 M V 3+ / 3.0 M H2SO4 (negative electrode). A uniform axial magnetic field with a strength of 0.3 T was applied to both sides of the membrane (perpendicular to the membrane surface). The tests were all conducted at 25°C.

[0048] Proton conductivity: Electrochemical impedance spectroscopy was used to obtain the membrane surface resistance by high-frequency region impedance fitting at an open circuit potential, and the proton conductivity was calculated.

[0049] Vanadium ion permeability: A static diffusion cell was used. One side of the membrane was 1.5 M VOSO4 / 3.0 M H2SO4 solution, and the other side was an equal volume of 1.5 M MgSO4 / 3.0 M H2SO4 solution. Under a magnetic field of 0.3 T, samples were taken at regular intervals, and the change in vanadium ion concentration on the MgSO4 side was measured by ultraviolet-visible spectrophotometry. The permeability was calculated according to Fick's law.

[0050] Mechanical strength: A universal material testing machine was used to test the tensile strength of the membrane according to GB / T 1040.3 standard.

[0051] The performance test results were as follows:

[0052] Proton conductivity: 0.16 S / cm;

[0053] Vanadium ion permeability: 9.5 × 10 -9 cm² / s;

[0054] Hydrogen / vanadium ion selectivity ratio (H + / VO 2+ ): 1.7 × 107 ;

[0055] Mechanical strength: 32 MPa.

[0056] Example 2

[0057] The preparation method of this example includes the following steps:

[0058] (1) Template preparation: A template with a hole diameter of 25 nm, a center distance of 120 nm, and a depth of 1.2 μm was prepared on a polycarbonate substrate using nanoimprint technology;

[0059] (2) Nanowire array electrodeposition:

[0060] Deposition solution: 0.05 M CoCl2, 0.02 M Pd(NH3)4Cl2, and 0.8 M sodium citrate were adjusted to a pH of 4.0 with ammonia water. The deposition temperature was 85°C. The deposition potential was -0.9 V for Co and -0.9 V for Pd. The Co / Pd single-layer deposition time was 1 second and 4 seconds, respectively, and was repeated for 60 cycles;

[0061] (3) Insulating layer coating: A 3 nm thick SiO2 layer was grown on the top of the nanowires using plasma-enhanced chemical vapor deposition;

[0062] (4) Array transfer and membrane compounding: The array was compounded with a 60 μm thick perfluorosulfonic acid membrane at 150°C and 15 MPa for 30 minutes. The subsequent processing was the same as in Example 1, and a proton exchange membrane with a thickness of 60 μm and a CoPd multilayer nanowire array on the surface was obtained.

[0063] Performance tests were conducted on this example:

[0064] The test conditions were the same as in Example 1, but the axial magnetic field strength was set to 1.2 T;

[0065] The test results are as follows:

[0066] Proton conductivity: 0.18 S / cm;

[0067] Vanadium ion permeability: 8.0 x 10 -9 cm² / s;

[0068] Hydrogen / vanadium ion selectivity ratio (H + / VO 2+ ): 2.3 x 10 7 ;

[0069] Mechanical strength: 35 MPa.

[0070] Example 3

[0071] The preparation method of this example includes the following steps:

[0072] (1) Template preparation: Silicon template was prepared by interference lithography combined with reactive ion etching technology, aperture 20 nm, center distance 100 nm;

[0073] (2) Nanowire array electrodeposition: Deposition solution, 0.03M CoSO4, 0.015M PdCl2, 0.6M H3BO3, pH = 3.5. Deposition temperature 80℃. Deposition potential: Co is -0.8V, Pd is -0.75V. Single layer deposition time is 0.7s and 2.8s respectively, 50 cycles in total;

[0074] (3) Insulating layer coating: Atomic layer deposition 2nm Al2O3;

[0075] (4) Array transfer and membrane composite: Hot-pressed with 30μm thick perfluorosulfonic acid membrane at 125℃, 10MPa for 20min; obtained a 30μm thick proton exchange membrane with CoPd multilayer nanowire array on the surface.

[0076] The performance test of this example was carried out as in Example 1, but the axial magnetic field strength was 0.8T.

[0077] The test results are as follows:

[0078] Proton conductivity: 0.22S / cm;

[0079] Vanadium ion permeability: 5.2×10 -9 cm² / s;

[0080] Hydrogen / vanadium ion selectivity ratio (H + / VO 2+ ): 4.2×10 7 ;

[0081] Mechanical strength: 38MPa.

[0082] Example 4

[0083] The same proton exchange membrane as in Example 3 was prepared in this example.

[0084] The performance test of this example was carried out as follows:

[0085] The test device was the same as in Example 2, but the magnetic field was provided by an electromagnet and a pulse power supply was used for control. The peak strength of the magnetic field was 1.0T, the pulse frequency was 1kHz, and the duty cycle was 30% (i.e. the magnetic field was turned on for 0.3ms and turned off for 0.7ms in each cycle). The test methods for proton conductivity and vanadium ion permeability were unchanged, and both were carried out in the pulse magnetic field mode. At the same time, the vanadium ion permeability after the magnetic field was turned off was tested;

[0086] The test results (under pulse magnetic field) are as follows:

[0087] Proton conductivity: 0.20 S / cm;

[0088] Vanadium ion permeability: 3.0 x 10 -9 cm2 / s;

[0089] Hydrogen / vanadium ion selectivity ratio (H + / VO 2+ ): 6.7 x 10 7 ;

[0090] Mechanical strength: 42 MPa.

[0091] Dynamic regulation contrast: after the pulse magnetic field is turned off, the vanadium ion permeability is measured to rise to ~2.0 x 10 -8 cm 2 / s, and the selectivity ratio is measured to drop to ~1.0 x 10 7 . After the pulse magnetic field is applied again, the performance is restored, proving the reversible dynamic regulation characteristics.

[0092] Example 5

[0093] The preparation method of this example includes the following steps

[0094] (1) Template preparation: AAO template is prepared on high-purity aluminum foil by a two-step anodization method. The ordered channels with a pore size of about 20 nm and a pore spacing of about 100 nm are obtained by oxidizing in a 0.3M oxalic acid solution at a voltage of 40V and a temperature of 5°C for 2 hours. After pore expansion by phosphoric acid, the aluminum base is removed by a copper chloride solution, and the bottom of the channel is opened by phosphoric acid to obtain a self-supporting AAO template;

[0095] (2) Nanowire array electrodeposition: the sputtered gold layer on one side of the AAO template is used as the working electrode, the deposition solution and process parameters are the same as in Example 3, and 50 [Co / Pd] cycles are deposited;

[0096] (3) Insulating layer and composite: Al2O3 coating is performed as in Example 3. The AAO template loaded with nanowires is directly hot-pressed with a perfluorosulfonic acid membrane (conditions are the same as in Example 3), and finally the AAO template is selectively etched away with a 5% H3PO4 solution;

[0097] The performance test of the example is carried out as in Example 3, and the test results are as follows:

[0098] Proton conductivity: 0.20 S / cm;

[0099] Vanadium ion permeability: 5.8 x 10 -9 cm2 / s;

[0100] Hydrogen / vanadium ion selectivity ratio (H + / VO 2+ ): 3.4 x 107 ;

[0101] Mechanical strength: 40 MPa.

[0102] Example 6:

[0103] The preparation method of the embodiment includes the following steps:

[0104] (1) Flexible template and array preparation: On a flexible polyimide substrate, a hole array template is prepared by nanoimprinting, and a conductive seed layer is pre-deposited in the template holes using a roll-to-roll sputtering device. Subsequently, in a continuous roll-to-roll electrodeposition device, the same deposition solution and potential parameters as in Example 3 are used to deposit a nanowire array with a period of 60;

[0105] (2) Roll-to-roll composite transfer: The flexible template roll with the grown nanowire array is simultaneously fed into a roll-to-roll hot press along with a rolled perfluorosulfonic acid resin matrix film (thickness 50 μm). The roll temperature is set to 130°C, the inter-roller pressure is 8 MPa, and the transmission line speed is 2 m / min. In the roll-to-roll contact area, the nanowire is hot-pressed into the surface of the resin film. Subsequently, the template is stripped and dissolved in a continuous etching tank to obtain a composite film finished roll;

[0106] Sample from the finished roll and perform performance testing, test conditions same as Example 3, test results as follows:

[0107] Proton conductivity: 0.19 S / cm;

[0108] Vanadium ion permeability: 6.5 x 10 -9 cm² / s;

[0109] Hydrogen / vanadium ion selectivity ratio (H + / VO 2+ ): 2.9 x 10 7；

[0110] Mechanical strength: 37 MPa.

[0111] The present application constructs a CoPd multilayer nanowire array with perpendicular magnetic anisotropy on the surface of a perfluorosulfonic acid resin matrix, creatively introduces an axial magnetic field to excite a spiral electromagnetic field gradient in the array gap, and uses the Lorentz force to achieve dynamic and reversible screening of hydrogen ions and vanadium ions. This scheme breaks through the bottleneck that traditional proton exchange membranes cannot simultaneously achieve high proton conductivity and high ion selectivity. Experiments have shown that the proton conductivity of this scheme can reach 0.22 S / cm, and the hydrogen / vanadium ion selectivity ratio can be as high as 10 7 The above, and the performance can be real-time regulated by a pulsed magnetic field, while also having excellent mechanical strength and industrialization preparation potential.

Claims

1. A magnetically controlled ion sieving proton exchange membrane, characterized in that, The application relates to a proton exchange membrane, which comprises a perfluorosulfonic acid resin matrix and a vertical magnetic anisotropy CoPd multilayer nanowire array deposited on the surface of the matrix, wherein the nanowire diameter is 15-25 nm, and the nanowire spacing is 80-120 nm. During use of the proton exchange membrane, a helical electromagnetic field gradient is generated by applying an axial magnetic field, and dynamic screening of vanadium ions and hydrogen ions is realized by utilizing Lorentz force, wherein the motion track of the vanadium ions is selectively deflected, and the hydrogen ions keep linear transmission. The CoPd multilayer nanowire is a multilayer structure, which is formed by periodic repetition of [Co / Pd] stacking, and the repetition period is 40-60; the nanowire structure has the characteristic of vertical magnetic anisotropy.

2. The magnetically controlled ion-sieveing proton exchange membrane according to claim 1, wherein, The nanowire top end is provided with an Al2O3 or SiO2 insulation layer with a thickness of 1-3 nm, which is used for preventing corrosion and reducing interface resistance.

3. The magnetically controlled ion-sieveing proton exchange membrane of claim 1, wherein, The strength of the axial magnetic field is 0.3-1.2 T.

4. The magnetically controlled ion-sieveing proton exchange membrane of claim 1, wherein, The proton exchange membrane has a proton conductivity ≥ 0.15 S / cm, a vanadium ion permeability ≤ 1.0 x 10 -8 cm 2 / s, and a selectivity ratio of hydrogen ions to vanadium ions ≥ 1.0 x 10 7 .

5. The magnetically controlled ion-sieveing proton exchange membrane of claim 1, wherein, The thickness of the proton exchange membrane is 10-60 mu m; and the mechanical strength is greater than or equal to 30 MPa.

6. A method for preparing the magnetically controlled ion-sieve proton exchange membrane according to any one of claims 1-5, characterized by, The application further discloses a preparation method of the proton exchange membrane. (1) A nanowire array template is prepared on a substrate by adopting electron beam lithography technology, nanoimprint technology, interference lithography combined with reactive ion etching technology or an anodic oxidation method; (2) A CoPd multilayer nanowire array is prepared on the template by an electrochemical atomic layer deposition method; (3) The nanowire array is transferred to the surface of a perfluorosulfonic acid resin matrix.

7. The method of claim 6, wherein the magnetic control ion sieves the proton exchange membrane. In step (2), the electrochemical deposition conditions include that the deposition temperature is 75-85 DEG C, the deposition potential is-0.7 V to-0.9 V relative to an Ag / AgCl reference electrode, and the deposition liquid pH value is 3.0-4.

0.

8. The method of claim 6, wherein the magnetic control ion sieves the proton exchange membrane. In step (3), the transfer is carried out by adopting a hot pressing method, the hot pressing temperature is 100-150 DEG C, the pressure is 5-15 MPa, and the time is 10-30 min; or a roll pressing process is used for roll-to-roll production.

9. Application of the magnetic control ion screening proton exchange membrane in a full vanadium liquid flow battery.

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