Low Resistance-area Research Articles

The vertical electrical sounding (VES) of the epikarst: A case study of the covered karst of the Bakony region (Hungary)

The epikarsts of five covered karst areas in the Bakony region are compared. The comparison is based on the specific resistances of the bedrock resistance averages measured by vertical electrical sounding (VES). The average largest specific resistance differences (per area) and the mean values (per profile) were calculated to investigate the characteristics of the epikarst. The mean values of specific resistance were compared using analysis of variance (ANOVA) to determine whether the specific resistances of the areas showed significant differences. The studied karst areas can be categorised as high or low specific resistance areas, and the ANOVA method could be applied to three areas based on the available data. It can be concluded that the mean values of their specific resistances are significantly different. The mean values and standard deviation of the specific resistances of the different areas were analysed. It is described that the karst receives less water in the case of areas with lower specific resistance, while it receives more water in the case of areas with higher specific resistance. Areas with a high specific resistance are less karstified, while areas with a low specific resistance are more karstified. Low specific resistances and small mean values indicate a higher degree of cavity formation in the epikarst, while the decrease in mean values and standard deviation indicates increasing uniformity of the degree of cavity formation in the epikarst. The different degree of cavity formation is explained by the different karstification rates and the exposure of different time of certain areas.

Comprehensive exploration approach of coal mine water-conducting channels in urban environment: a case study in Xintai, China.

In the process of coal mining, prevention and control of water hazard is essential. It is the precondition for water hazard control to detect and determine the distribution of underground water-conducting channels. In urban environments, traditional methods such as active source seismic exploration and transient electromagnetic exploration commonly used in the field are difficult to carry out effectively due to various factors. In this paper, the microtremor survey method (MSM) and the opposing coils transient electromagnetic method (OCTEM) are adapted to conduct the surface exploration of the coal mine water-conducting channels in the urban environment. Combined with the detection results of the low-velocity area and the low-resistivity area, the distribution of water-conducting channels is preliminarily analyzed and determined, which is basically consistent with the drilling and coring results. It verifies the feasibility and accuracy of the comprehensive exploration method used in this paper.

Highly stable side-chain-type cardo poly(aryl ether ketone)s membranes for vanadium flow battery

Vanadium flow batteries (VFBs) have drawn considerable attention as an emerging technology for large-scale energy storage systems (ESSs). One of the pivotal challenges is the availability of eligible ion exchange membranes (ICMs) that provide high ion selectivity, proton conductivity, and stability under rigorous condition. Herein, a ‘side-chain-type’ strategy has been employed to fabricate highly stable phenolphthalein-based cardo poly(arylene ether ketone)s (PAEKs) membrane with low area resistance (0.058 Ω cm2), in which flexible alkyl spacers effectively alleviated inductive withdrawing effect from terminal ion exchange groups thus enabling a stable backbone. The assembled VFBs based on PAEKs bearing pendent alkyl chain terminated with quaternary ammonium (Q-PPhEK) demonstrated an energy efficiency above 80% over 700 cycles at 160 mA/cm2. Such a remarkable results revealed that the side-chain-type strategy contributed to enhancing the ICMs stability in strong oxidizing environment, meanwhile, more interesting backbones would be woken with this design engaging in stable ICMs for VFBs.

Highly positively-charged membrane enabled by a competitive reaction for efficient Li+/Mg2+ separation

Advanced monovalent cation exchange membranes (MCEMs) have been applied to extract key monovalent cations (Li+ or Na+) from nature, but it is challenging to design high-performance MCEMs with low membrane area resistance and specific charge properties. Herein, a positively-charged Fe3+-bridged pyrogallic/polyethyleneimine membrane (Fe3+-bridged PY/PEIM) for efficient Li+/Mg2+ separation is fabricated through a covalent bond and coordination bond (CB/COB) competitive reaction. Various physicochemical characterizations elucidate that the formation of COBs reduces the reaction sites of PY and PEI molecules for Michael-addition and Schiff-base reactions, which reduces the thickness of the selective layers to reduce the membrane area resistance from 6.58 to 4.83 Ω·cm2. A highly positively-charged selective layer caused by unreacted NH2 groups and Fe3+ makes the optimal Fe3+-bridged PY/PEIM exhibit a superior separation performance (perm-selectivity (Li+/Mg2+) of 45.57 with a Li+ flux of 4.61 × 10−8 mol·cm−2·s−1). Moreover, the optimal Fe3+-bridged PY/PEIM also has excellent separation performance (high Li+ flux and perm-selectivity) and operational stability when treating three simulated solutions with different Mg/Li mass ratios and salinities. The new strategy for constructing a thin, defect-free and positively-charged selective layer through a CB/COB competitive reaction can provide new insights for designing high-performance MCEMs towards environmental remediation and energy harvesting.

A thin and flexible composite membrane with low area resistance and high bubble point pressure for advanced alkaline water electrolysis

Green hydrogen plays a pivotal role in the decarbonizing process. Hydrogen production by alkaline water electrolysis (AWE) is the most promising way for large-scale hydrogen production because of the merits of high-efficient and cost-effective. In the AWE system, the membrane is used to conduct hydroxide ions and block the interpenetration of hydrogen and oxygen, which is a crucial component. However, the current membranes are limited by either the high area resistance or inadequate gas-blocking ability. Herein, we proposed a thin (∼268 μm) and flexible composite membrane featuring both low area resistance (∼0.14 Ω cm2 in 30 wt% KOH solution) and high bubble point pressure (BPP, ∼24 bar). When applied in alkaline water electrolysis, the composite membrane with the commercial NiMo and NiFe catalysts shows a current density of 2.3 A cm-2 at the voltage of 2 V in 30 wt% KOH solution at 80 °C, surpassing the capabilities of the ZIRFON UTP 500 membrane. Notably, the in-situ gas purity tests reveal an impressive hydrogen purity of ∼99.997%, much higher than that of the state-of-the-art membranes. Additionally, the stability tests conducted more that 600 h at 80 °C without performance attenuation highlight the membrane's competitiveness and promising commercial prospects.

A Porous Skeleton‐Supported Organic/Inorganic Composite Membrane for High‐Efficiency Alkaline Water Electrolysis

AbstractHydrogen energy is a truly renewable and clean energy source. Alkaline water electrolysis (AWE) is the most promising technology for green hydrogen production currently. In the AWE process, the critical part of an alkaline electrolyzer is the membrane, which acts to conduct hydroxide ions and block gases. However, developing low area resistance, high bubble point pressure and highly stable membrane for high‐performance AWE is still a challenge. Herein, porous skeleton‐supported composite membranes via the blade‐coating method for advanced AWE are prepared. The porous composite membranes, besides having hydrophilic surface, also show ultra‐low area resistance (≈0.15 Ω cm2), ultra‐high bubble point pressure (≈27 bar) and excellent mechanical properties (tensile stress, ≈14 MPa). By using commercial catalysts, the composite membranes exhibit a current density of up to 1.9 A cm−2 at the voltage of 2 V in 30 wt% KOH solution at 80 °C and achieve ultra‐high H2 purity (up to 99.996%) when applied in AWE. Notably, the composite membrane can operate for more than 1600 h without performance attenuation, demonstrating excellent stability. This study opens up the feasibility of preparing high‐performance AWE membranes for large‐scale hydrogen production.

Study on the cooling and drag reduction characteristics of multi-port injector array film cooling using gaseous hydrocarbon fuel as coolant

Supersonic film cooling utilizing gaseous hydrocarbon fuel is an effective method to meet the thermal protection and drag reduction requirements inside a scramjet engine. The film injection scheme for film cooling using gaseous hydrocarbon fuel is crucial in determining the thermal protection and drag reduction performance of the film with oxidative cracking reaction. In this paper, a numerical study is conducted to compare the thermal protection and drag reduction performance of gaseous hydrocarbon fuel film under the slot injector film cooling structure and the multi-port injector array film cooling structure. The results show that the multi-port injector array film cooling utilizing gaseous hydrocarbon fuel as a coolant improves both thermal protection and drag reduction performance compared to the slot injector film cooling structure. The chemical reaction of hydrocarbon fuel expands the cooling range and low resistance area of a single discrete hole. The reason is that the multi-port injector array film cooling intermittently interrupts the oxidation and heat release process of the hydrocarbon fuel in the boundary layer, resulting in higher cooling efficiency in the film cooling injection area. It also improves the spatial distribution of the hydrocarbon fuel film, allowing for effective utilization of the chemical heat sink of the hydrocarbon fuel, which improves the thermal protection performance and expands the effective cooling area. Furthermore, the enhanced mixing of the multi-port injector array film cooling in the film injection area improves drag reduction performance through combustion inside the boundary layer, resulting in a significant drag reduction of 36.6%. The multi-port injector array film cooling also effectively distributes the low skin-friction resistance region due to the low molecular viscosity after the secondary cooling flow injection. Moreover, under supersonic mainstream conditions, the mixing efficiency of the multi-port injector array film cooling structure and the slot injector film cooling structure both decreases, and the difference gradually decreases.

Carbon Nanowalls as Anode Materials with Improved Performance Using Carbon Nanofibers.

In this paper, a new synthesis of carbon nanofibers (CNFs)/carbon nanowalls (CNWs) was performed to improve the characteristics of anode materials of lithium-ion batteries by using the advantages offered by CNWs and CNFs. Among the carbon-based nanomaterials, CNWs provide low resistance and high specific surface area. CNFs have the advantage of being stretchable and durable. The CNWs were grown using a microwave plasma-enhanced chemical vapor deposition (PECVD) system with a mixture of methane (CH4) and hydrogen (H2) gases. Polyacrylonitrile (PAN) and N,N-Dimethyl Formamide (DMF) were stirred to prepare a solution and then nanofibers were fabricated using an electrospinning method. Heat treatment in air was then performed using a hot plate for stabilization. In addition, heat treatment was performed at 800 °C for 2 h using rapid thermal annealing (RTA) to produce CNFs. A field emission scanning electron microscope (FE-SEM) was used to confirm surface and cross-sectional images of the CNFs/CNWs anode materials. Raman spectroscopy was used to examine structural characteristics and defects. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and constant current charge/discharge tests were performed to analyze the electrical characteristics. The synthesized CNFs/CNWs anode material had a CV value in which oxidation and reduction reactions were easily performed, and a low Rct value of 93 Ω was confirmed.

Metal Contact on P-Type 4H-SiC With Low Specific Contact Resistance and Micrometer-Scale Contact Area

Metal Contact on P-Type 4H-SiC With Low Specific Contact Resistance and Micrometer-Scale Contact Area

Highly permselective polyvinylidene fluoride-based cation-exchange membranes containing phosphorated graphene oxide for electrodialysis

Phosphorated graphene oxide (PGO) was used to prepare polyvinylidene fluoride (PVDF)-based cation-exchange membrane for the electrodialysis (ED) process. The influences of PGO wt% on the physicochemical and electrochemical characteristics of the PVDF/PGO membranes were studied using different characterization methods. The morphology, oxidative stability, permselectivity, ion transport number, and electrochemical properties of the best PVDF/PGO membrane were compared with those of the bare Nafion-117 membrane and PVDF/GO membrane containing the same wt% of GO. The membrane containing 60 wt% PGO (PVDF/PGO60) exhibited a high water uptake of 44.69%, which was about 2.5 and 2 times higher than that achieved from PVDF/GO60 and Nafion, respectively. PVDF/PGO60 provided a considerably higher (∼10 times) ion exchange capacity (IEC) than Nafion. Electrochemical analysis revealed that Na+ ions enjoyed a high diffusion coefficient within PVDF/PGO60, which was comparable to Nafion-117. This resulted in a low area resistance of 2.4 ± 0.3 Ω cm2, high permselectivity of 96.4%, and transport number of 97.8%. Moreover, PVDF/PGO60 exhibited a low weight loss of 1.90%, and a moderate resistance change of 19.79% after being immersed in the Fenton reagent for 9 h. The desirable electrochemical properties, and oxidative and mechanical stability of PVDF/PGO60 suggest that the PGO-containing PVDF-based membranes can be considered promising CEMs for application in the electromembrane desalination processes.

Deep structure of the Rongcheng geothermal field, Xiongan New Area: Constraints from resistivity data and boreholes

The development of the Xiongan New Area is China's exploration into the future of urban design, with plentiful geothermal resources serving as a crucial component for building a green, ecological and habitable city. However, the region currently lacks high-precision geophysical exploration research. The boundaries of each sub-tectonic unit and the unclear distribution of deep strata impede further drilling and efficient geothermal resources development. Wide field electromagnetic method (WFEM) provides superior detection depth and high precision compared to the traditional electromagnetic methods. We obtained a high-precision resistivity model of Rongcheng geothermal field through two WFEM survey lines (343 stations) for the first time. This model distinctly illustrates the stratigraphic framework of the Quaternary-Neogene-Jixian system, and accurately reveals the spatial locations of the Rongcheng Bulge, Niutuozhen Bulge, Niubei Slope, and the Dahezhen Depression within the Xiongan New Area. Moreover, the model provided a more precise representation of the faults and strata structure, reinforced by two boreholes. The low resistivity area within the Rongcheng Bulge has a large potential for geothermal resources. Conversely, the low resistivity area at a depth of 4000 m in the Niubei Slope was formed by fractures and groundwater activities, and presumed to be a water-rich area, indicating a favorable area for future geothermal investigation. Thus, our study can provide fundamental data for the upcoming geological researches and geothermal development in the Xiongan New Area.

A Three-Dimensional Hydraulic Stack Model for Redox Flow Batteries Considering Porosity Variations in Porous Felt Electrodes and Bypass Flow in Side Gaps

Redox flow batteries provide high flexibility and scalability for large-scale energy storage systems due to their safety, low cost and decoupling of energy and power. While typical flow frame designs usually assume all parts are standard, the industry can suffer from irregularity and manufacturing tolerances of cell components, such as the shape or dimensions of the flow frame and porous electrode. This paper evaluates the impact of side gaps and porosity differences of the graphite felt due to irregularity and manufacturing tolerances on the electrolyte flow in the active cell areas. A three-dimensional hydraulic model with parameterised multi-cell stack geometry has been developed in COMSOL to compare the cell velocity distributions and pressure losses of a vanadium redox flow battery with flow-through electrodes. The results indicate that the side gaps and porosity segments can result in preferential flow within low-resistance areas, leading to significantly lower flow rates for other cell areas compared with standard flow frames. Proposed countermeasures of adjusting channel locations and applying dimples protruding into the cell cavity from the flow frame show good potential to avoid stagnant zones and maintain theoretical flow rates for the active cell areas.

Highly hydrophilic polybenzimidazole/Zirconia composite separator with reduced gas crossover for alkaline water electrolysis

Porous separators have been widely used in alkaline water electrolyzers (AWEs). To solve the problem of high gas permeability and stability caused by the large pores and poor compatibility of commercial Zirfon separators, it is important to develop a diaphragm with high OH− conductivity, high bubble point pressure, low area resistance, and low hydrogen permeability for alkaline electrolyzers. Here, we proposed highly hydrophilic polybenzimidazole-type composite porous separators with specific sponge-like pores via nonsolvent-induced phase separation. The high hydrophilicity of poly(2, 2'-(1, 4-naphthalene)-5, 5′-dibenzimidazole) (NPBI) and ZrO2 enhanced the interfacial interaction to prevent filler overflow. Compared to the Zirfon separator, the area resistance and hydrogen permeability of the proposed separators were significantly reduced. The Z60 diaphragm exhibited a higher water absorption rate (62.2%) and KOH liquid absorption rate (23.5%), lower area resistance (0.162 Ω cm2), higher bubble pressure (4.48 bar), and lower hydrogen permeability (2.63 L min−1·cm−2). Moreover, the voltage of the Z60 diaphragm was 2.007 V at 0.5 A/cm2 in 6 M KOH, which is comparable to commercial Zirfon. The Z60 separator used for AWEs with Ni foam catalysts obtained an excellent long-term stability of up to 400 h with a voltage fluctuation of only 55 μV/h. Therefore, the design of the NPBI/ZrO2 porous composite diaphragm provides a new idea for the development of high-performance alkaline water electrolysis.

Geophysical and hydro-chemical investigation of Ekehuan dumpsite, Benin City, Southern Nigeria

Geophysical and hydro-chemical analyses have been undertaken in Ekehuan dumpsite in Benin City, Southern Nigeria, to access the impact of effluent from the dumpsite on the groundwater system. The aim of this study is to determine and delineate the extent of pollution generated by leachate in the dumpsite on the groundwater using electrical resistivity technique in concert with hydro chemical analysis. Seven (7) vertical electric soundings (VES) and three (3) dipole–dipole profiling were carried out within and around the dumpsite. Hydro-chemical analysis of the ground water samples was analyzed using the atomic absorption spectrometer (AAS). The results from electrical surveys showed that the study area is underlain by five to eight geoelectric layers with resistivity values ranging from 14.9 to 250.8 Ohm-m, 90.3–3049.3 Ohm-m, 6.9–1364.7 Ohm-m, 24.9–3050.8 Ohm-m, 54.0–999.4 Ohm-m, 37.3–818.4 Ohm-m, 140.4–3243.1 Ohm-m and 187.9–3511.7 Ohm-m respectively; with various thicknesses and lithologies. The dipole–dipole profiling results showed areas of low resistivity between 160 and 180 ​m, 225–240 ​m and 265–315 ​m distances for dipole 1; 40–70 ​m and 90–125 ​m for dipole 2, 85–120 ​m for dipole 3; indicating the presence of leachate. The result from the hydro-chemical analysis showed that the heavy metals were seen to be within the permissible limit of (World Health Organization, 2017) and (Nigeria Standard of Drinking Water Quality, 2007).

VRFBs based on benzotriazole grafted polybenzimidazole / polymeric ionic liquid with high ion selectivity

A series of innovative branching OPBI composite membranes (OPBI-BTZ-PIL) were created based on benzotriazole side chain grafted OPBI (OPBI-BTZ) and double-bond ionic liquids for vanadium redox flow battery applications. The benzotriazole contained three nitrogen sites, which helped enhance the proton conductivity and low area resistance. The cation in the polymeric ionic liquid in the matrix and the vanadium ion produces the Donnan effect, which reduces vanadium permeability. Moreover, the hydrogen bond cross-linking network formed by the polymeric ionic liquid in the membrane further helps proton transport. The vanadium permeability of OPBI-BTZ10-PIL10 is as low as 1.51 × 10−9 cm2 min−1, which is one 40th of the Nafion117 (62.54 × 10−9 cm2 min−1). Its ion selectivity is up to 2.45 × 106 S min cm−3. The OPBI-BTZ10-PIL10 membrane performs well at 60 mA cm−2, with CE of 94.12% and EE of 86.2%, both of which are higher than the Nafion117 membrane.

Electrochemical sensor based on MOF derived LaFexNi(1-x)O3 using carbon spheres as the template for simultaneous determination of p-aminophenol and paracetamol

Using metal–organic frameworks (MOFs) as the precursor and carbon spheres as the template, LaFexNi(1-x)O3 (x = 1, 0.8, 0.6, 0.4, 0.2, 0) perovskite-type oxides were synthesized. The structure, morphology and valence state of as-prepared perovskite-type oxides were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy, and X-ray photoelectron spectroscopy. Cyclic voltammetry and electrochemical impedance techniques were used to study the effect of Ni-doping ratios on the electrocatalytic performance of perovskite. The differential pulse voltammetry was used to measure the content of p-aminophenol (PAP) and paracetamol (PAT) through the LaFe0.6Ni0.4O3 modified glassy carbon electrode. The experiment shows that among LaFexNi(1-x)O3 (x = 1, 0.8, 0.6, 0.4, 0.2, 0) perovskite-type oxides, LaFe0.6Ni0.4O3 was best electrode material due to its low charge transfer resistance and high electrochemical active surface area. The linear ranges of PAP and PAT were both 1.0–100.0 μM under optimized conditions, while the detection limits were 0.111 and 0.162 μM (S/N = 3), respectively. The practicality of the suggested sensor was explored through the simultaneous detection of PAP and PAT in real samples, and satisfactory findings in acetaminophen pills were obtained.

Contamination assessment and availability of potential toxic elements from the Sidi Driss tailing pile (NW Tunisia) based on geochemical and geophysical methods

Mine wastes are of particular relevance, either because they represent a source of contamination by potential toxic elements (PTEs), or even because the high concentrations of some critical raw materials with economic interest can make their mining viable in the future.This work presents mineralogical, geochemical, and geophysical data aimed at a detailed characterization of an old tailing pile of the Sidi Driss mine (northern Tunisia) that exploited Pb and Zn concentrates. The results obtained from four drilling boreholes, reaching a maximum depth of 11 m, show high concentrations of metal(loid)s in the tailings, namely As, Ba, Cd, Mn, Pb and Zn. Apart from barium, the higher concentrations of these PTEs were found between 3 and 8 m depth. The availability of such metal(loid)s is higher in deeper sections of the tailing pond than on the surface, which is explained by the reduction and oxidation environments prevailing at these depths, respectively. Thus, at surface sulphides are oxidised and several metal(loid)s are released and leached. This oxidation process generates acid mine drainage (AMD), causing the dissolution of carbonates, such as cerussite, from which Pb is released and leached underground. In deeper sections of the tailing pond, reduction conditions prevent sulphide oxidation and the prevalence of circumneutral pH values. In such environments, carbonates are not dissolved and Pb leached from the surface precipitates (e.g., as anglesite, an insoluble sulphate), as demonstrated by sequential selective chemical extraction.Electrical resistivity tomography (ERT) showed low resistivity areas from surface to 8 m depth. This is a consequence of waterlogging on the surface (due to rainy events) and, on the subsurface, of high metal(loid) contents in tailings. High electrical resistivity was measured below this level (bedrock), but a connection between heavily contaminated horizons (tailings) and a subsequent layer of low resistivities (associated with groundwater) is observed, which is of particular concern.

Highly Efficient Alkaline Water Electrolysis Using Alkanolamine-Functionalized Zirconia-Blended Separators

Alkaline water electrolysis is one of the most promising technologies for green hydrogen production. Here, we synthesized a series of alkanolamine-modified zirconia particles by a one-pot method to construct zirconia-based composite membranes for alkaline water electrolysis. Among these membranes, the diethanolamine (DEA)-functionalized zirconia separator exhibits superior hydrophilicity with a low water contact angle of 44° and low area resistance of 0.12 Ω·cm2, which were 47 and 60%, respectively, less than that of the commercial Zirfon PERL UTP 500 separator. Conceivably, the DEA-functionalized zirconia separator presents high electrochemical performance with a current density of 1114 mA cm–2 at 2.0 V with Raney Ni as the cathode catalyst and CoMnO@CoFe layered double hydroxide (LDH) as the anode catalyst at 80 °C, closing the gap with proton exchange membrane electrolysis. In addition, the DEA-modified separator exhibits high stability for over 150 h at a high current density of 500 mA cm–2 and stable cell voltages in 30 wt % KOH at 80 °C.

Enhanced tunneling electroresistance effect in Pt/BiAlO3/Pt ferroelectric tunnel junctions by a graphene interlayer

Realizing a large tunneling electroresistance (TER) effect with a low ON-state resistance-area product (RAP) is essential for the applications of ferroelectric tunnel junctions (FTJs) in information storage. Herein, taking Pt/BiAlO3/Pt (Pt/BAO/Pt) FTJs as examples, we theoretically demonstrate that a giant TER ratio of about 1458%, which is comparable to most van der Waals tunnel junctions, can be achieved by switching the electric polarization of ferroelectric BAO(0001) barrier due to the reversible metallization of ferroelectric in conjunction with the Schottky barrier. More interestingly, with the effective modulation on barrier height and width via polarization reversal, an enhanced TER effect close to 104% can be obtained by inserting a graphene monolayer into right (or left) Pt/BAO interface of the FTJs and the writing endurance of the FTJ memories is expected to be significantly improved. Furthermore, the calculated ON-state RAPs in all three FTJ devices are not more than 100 Ω μm2. These fascinating findings suggest that the proposed BAO-based FTJs hold great potential for designing next-generation nanoscale high-density and low-power nonvolatile memories with excellent performance.

Long side-chain imidazolium functionalized poly(vinyl chloride) membranes with low cost and high performance for vanadium redox flow batteries

Developing polymer membranes with low price, superior ion conduction and good vanadium ion transport resistance is currently a hot topic in vanadium redox flow batteries (VRFBs). In the present work, long side-chain imidazolium functionalized poly(vinyl chloride) (PVC) membranes are fabricated to provide a versatile strategy for the ion transport and selectivity trade-off in VRFBs. PVC is employed as the membrane matrix owing to its low price, high tensile strength and natural chlorine groups. 1-(3-Aminopropyl) imidazole (APIm) is grafted into PVC via a facile nucleophilic reaction, which provides the basic groups as the interaction sites for sulfonic acid, resulting in low area resistance. Meanwhile, due to the electrostatic repulsion effect of positively charged imidazolium cations between vanadium ions, APIm-PVC membranes display low vanadium ion permeability. Consequently, the 80 %APIm-PVC membrane has both low area resistance of 0.268 Ω∙cm2 and low vanadium ion permeability of 9.0 × 10−8 cm2∙min−1 simultaneously, achieving a 5 times higher ion selectivity (2.65 × 105 S min cm−3) than Nafion 115 (0.52 × 105 S min cm−3). The VRFB equipped with the 80 %APIm-PVC membrane shows higher battery efficiencies than the cell with Nafion 115 ranging from 100 to 160 mA∙cm−2, and also possesses excellent cycle constancy, indicating that low-cost x%APIm-PVC membranes have a great application potentiality for VRFBs.