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17 pages, 5313 KiB

Open AccessArticle

Improving PFSA Membranes Using Sulfonated Nanodiamonds

by Alexandr V. Shvidchenko, Alexei S. Odinokov, Oleg N. Primachenko, Iosif V. Gofman, Natalia P. Yevlampieva, Elena A. Marinenko, Vasily T. Lebedev, Alexander I. Kuklin and Yuri V. Kulvelis

Membranes 2023, 13(8), 712; https://doi.org/10.3390/membranes13080712 - 1 Aug 2023

Cited by 3 | Viewed by 1473

Abstract

Aquivion^®-type perfluorosulfonic acid membranes with a polytetrafluoroethylene backbone and short side chains with sulfonic acid groups at the ends have great prospects for operating in hydrogen fuel cells. To improve the conducting properties of membranes, various types of nanofillers can be [...] Read more.

Aquivion^®-type perfluorosulfonic acid membranes with a polytetrafluoroethylene backbone and short side chains with sulfonic acid groups at the ends have great prospects for operating in hydrogen fuel cells. To improve the conducting properties of membranes, various types of nanofillers can be used. We prepared compositional Aquivion^®-type membranes with embedded detonation nanodiamond particles. Nanodiamonds were chemically modified with sulfonic acid groups to increase the entire amount of ionogenic groups involved in the proton conductivity mechanism in compositional membranes. We demonstrated the rise of proton conductivity at 0.5–2 wt.% of sulfonated nanodiamonds in membranes, which was accompanied by good mechanical properties. The basic structural elements, conducting channels in membranes, were not destroyed in the presence of nanodiamonds, as follows from small-angle neutron scattering data. The prepared compositional membranes can be used in hydrogen fuel cells to achieve improved performance. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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12 pages, 3385 KiB

Open AccessArticle

High-Conductive CsH₂PO₄ Membranes with PVDF-Based Polymers Additives

by Irina Bagryantseva, Valentina Ponomareva and Yuri Kungurtsev

Membranes 2023, 13(7), 617; https://doi.org/10.3390/membranes13070617 - 22 Jun 2023

Viewed by 1372

Abstract

The study is devoted to one of the important problems of hydrogen energy—the comparative analysis and creation of novel highly conductive and durable medium-temperature proton membranes based on cesium dihydrogen phosphate and fluoropolymers. The proton conductivity, structural characteristics and mechanical properties of (1 [...] Read more.

The study is devoted to one of the important problems of hydrogen energy—the comparative analysis and creation of novel highly conductive and durable medium-temperature proton membranes based on cesium dihydrogen phosphate and fluoropolymers. The proton conductivity, structural characteristics and mechanical properties of (1 − x)CsH₂PO₄-x fluoropolymer electrolytes (x-mass fraction, x = 0–0.3) have been investigated and analyzed. UPTFE and PVDF-based polymers (F2M, F42, and SKF26) with high thermal stability and mechanical properties have been chosen as polymer additives. The used fluoropolymers are shown to be chemical inert matrices for CsH₂PO₄. According to the XRD data, a monoclinic CsH₂PO₄ (P2₁/m) phase was retained in all of the polymer electrolytes studied. Highly conductive and mechanically strong composite membranes with thicknesses of ~50–100 μm were obtained for the soluble fluoropolymers (F2M, F42, and SKF26). The size and shape of CsH₂PO₄ particles and their distribution have been shown to significantly affect proton conductivity and the mechanical properties of the membranes. The thin-film polymer systems with uniform distributions of salt particles (up to ~300 nm) were produced via the use of different methods. The best results were achieved via the pretreatment of the suspension in a bead mill. The ability of the membranes to resist plastic deformation increases with the growth of the polymer content in comparison with the pure CsH₂PO₄, and the values of the mechanical strength characteristics are comparable to the best low-temperature polymer membranes. The proton-conducting membranes (1 − x)CsH₂PO₄-x fluoropolymer with the optimal combination of the conductivity and mechanical and hydrophobic properties are promising for use in solid acid fuel cells and other medium-temperature electrochemical devices. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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15 pages, 6174 KiB

Open AccessArticle

Self-Phosphorylated Polybenzimidazole: An Environmentally Friendly and Economical Approach for Hydrogen/Air High-Temperature Polymer-Electrolyte Membrane Fuel Cells

by Igor I. Ponomarev, Dmitry Y. Razorenov, Kirill M. Skupov, Ivan I. Ponomarev, Yulia A. Volkova, Konstantin A. Lyssenko, Anna A. Lysova, Elizaveta S. Vtyurina, Mikhail I. Buzin and Zinaida S. Klemenkova

Membranes 2023, 13(6), 552; https://doi.org/10.3390/membranes13060552 - 25 May 2023

Cited by 4 | Viewed by 1569

Abstract

The development of phosphorylated polybenzimidazoles (PBI) for high-temperature polymer–electrolyte membrane (HT-PEM) fuel cells is a challenge and can lead to a significant increase in the efficiency and long-term operability of fuel cells of this type. In this work, high molecular weight film-forming pre-polymers [...] Read more.

The development of phosphorylated polybenzimidazoles (PBI) for high-temperature polymer–electrolyte membrane (HT-PEM) fuel cells is a challenge and can lead to a significant increase in the efficiency and long-term operability of fuel cells of this type. In this work, high molecular weight film-forming pre-polymers based on N¹,N⁵-bis(3-methoxyphenyl)-1,2,4,5-benzenetetramine and [1,1′-biphenyl]-4,4′-dicarbonyl dichloride were obtained by polyamidation at room temperature for the first time. During thermal cyclization at 330–370 °C, such polyamides form N-methoxyphenyl substituted polybenzimidazoles for use as a proton-conducting membrane after doping by phosphoric acid for H₂/air HT-PEM fuel cells. During operation in a membrane electrode assembly at 160–180 °C, PBI self-phosphorylation occurs due to the substitution of methoxy-groups. As a result, proton conductivity increases sharply, reaching 100 mS/cm. At the same time, the current-voltage characteristics of the fuel cell significantly exceed the power indicators of the commercial BASF Celtec^® P1000 MEA. The achieved peak power is 680 mW/cm² at 180 °C. The developed approach to the creation of effective self-phosphorylating PBI membranes can significantly reduce their cost and ensure the environmental friendliness of their production. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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16 pages, 3698 KiB

Open AccessArticle

Self-Standing, Ultrasonic Spray-Deposited Membranes for Fuel Cells

by Ali Karaca, Irina Galkina, Yoo Jung Sohn, Klaus Wippermann, Fabian Scheepers, Andreas Glüsen, Meital Shviro, Martin Müller, Marcelo Carmo and Detlef Stolten

Membranes 2023, 13(5), 522; https://doi.org/10.3390/membranes13050522 - 17 May 2023

Cited by 1 | Viewed by 1752

Abstract

The polymer electrolyte membrane and its contact with electrodes has a significant effect on the performance of fuel and electrolysis cells but the choice of commercially available membranes is limited. In this study, membranes for direct methanol fuel cells (DMFCs) were made by [...] Read more.

The polymer electrolyte membrane and its contact with electrodes has a significant effect on the performance of fuel and electrolysis cells but the choice of commercially available membranes is limited. In this study, membranes for direct methanol fuel cells (DMFCs) were made by ultrasonic spray deposition from commercial Nafion solution; the effect of the drying temperature and presence of high boiling solvents on the membrane properties was then analyzed. When choosing suitable conditions, membranes with similar conductivity, water uptake, and higher crystallinity than comparable commercial membranes can be obtained. These show similar or superior performance in DMFC operation compared to commercial Nafion 115. Furthermore, they exhibit low permeability for hydrogen, which makes them attractive for electrolysis or hydrogen fuel cells. The findings from our work will allow for the adjustment of membrane properties to the specific requirements of fuel cells or water electrolysis, as well as the inclusion of additional functional components for composite membranes. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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13 pages, 2012 KiB

Open AccessArticle

Development of High-Performance Hydrogen-Air Fuel Cell with Flourine-Free Sulfonated Co-Polynaphthoyleneimide Membrane

by Ulyana M. Zavorotnaya, Igor I. Ponomarev, Yulia A. Volkova and Vitaly V. Sinitsyn

Membranes 2023, 13(5), 485; https://doi.org/10.3390/membranes13050485 - 29 Apr 2023

Cited by 2 | Viewed by 1688

Abstract

This paper presents research on the technological development of hydrogen-air fuel cells with high output power characteristics using fluorine-free co-polynaphtoyleneimide (co-PNIS) membranes. It is found that the optimal operating temperature of a fuel cell based on a co-PNIS membrane with the hydrophilic/hydrophobic blocks [...] Read more.

This paper presents research on the technological development of hydrogen-air fuel cells with high output power characteristics using fluorine-free co-polynaphtoyleneimide (co-PNIS) membranes. It is found that the optimal operating temperature of a fuel cell based on a co-PNIS membrane with the hydrophilic/hydrophobic blocks = 70/30 composition is in the range of 60–65 °C. The maximum output power of a membrane-electrode assembly (MEA), created according to the developed technology, is 535 mW/cm², and the working power (at the cell voltage of 0.6 V) is 415 mW/cm². A comparison with similar characteristics of MEAs based on a commercial Nafion 212 membrane shows that the values of operating performance are almost the same, and the maximum MEA output power of a fluorine-free membrane is only ~20% lower. It was concluded that the developed technology allows one to create competitive fuel cells based on a fluorine-free, cost-effective co-polynaphthoyleneimide membrane. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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17 pages, 11532 KiB

Open AccessArticle

Proton-Conducting Polymer-Coated Carbon Nanofiber Mats for Pt-Anodes of High-Temperature Polymer-Electrolyte Membrane Fuel Cell

by Kirill M. Skupov, Igor I. Ponomarev, Elizaveta S. Vtyurina, Yulia A. Volkova, Ivan I. Ponomarev, Olga M. Zhigalina, Dmitry N. Khmelenin, Evgeny N. Cherkovskiy and Alexander D. Modestov

Membranes 2023, 13(5), 479; https://doi.org/10.3390/membranes13050479 - 29 Apr 2023

Cited by 3 | Viewed by 2153

Abstract

High-temperature polymer-electrolyte membrane fuel cells (HT-PEM FC) are a very important type of fuel cell since they operate at 150–200 °C, allowing the use of hydrogen contaminated with CO. However, the need to improve stability and other properties of gas diffusion electrodes still [...] Read more.

High-temperature polymer-electrolyte membrane fuel cells (HT-PEM FC) are a very important type of fuel cell since they operate at 150–200 °C, allowing the use of hydrogen contaminated with CO. However, the need to improve stability and other properties of gas diffusion electrodes still hinders their distribution. Anodes based on a mat (self-supporting entire non-woven nanofiber material) of carbon nanofibers (CNF) were prepared by the electrospinning method from a polyacrylonitrile solution followed by thermal stabilization and pyrolysis of the mat. To improve their proton conductivity, Zr salt was introduced into the electrospinning solution. As a result, after subsequent deposition of Pt-nanoparticles, Zr-containing composite anodes were obtained. To improve the proton conductivity of the nanofiber surface of the composite anode and reach HT-PEMFC better performance, dilute solutions of Nafion^®, a polymer of intrinsic microporosity (PIM-1) and N-ethyl phosphonated polybenzimidazole (PBI-OPhT-P) were used to coat the CNF surface for the first time. These anodes were studied by electron microscopy and tested in membrane-electrode assembly for H₂/air HT-PEMFC. The use of CNF anodes coated with PBI-OPhT-P has been shown to improve the HT-PEMFC performance. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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16 pages, 15203 KiB

Open AccessArticle

Features of the Degradation of the Proton-Conducting Polymer Nafion in Highly Porous Electrodes of PEM Fuel Cells

by Andrey A. Nechitailov, Polina Volovitch, Nadezhda V. Glebova and Anna Krasnova

Membranes 2023, 13(3), 342; https://doi.org/10.3390/membranes13030342 - 16 Mar 2023

Cited by 4 | Viewed by 2589

Abstract

The stability of new membrane–electrode assemblies of a proton-exchange membrane fuel cell with highly porous electrodes and low Pt loading, based on the proton-conducting polymer Nafion, was characterized in conditions of electrochemical aging. A comprehensive study of the effect of the microstructure on [...] Read more.

The stability of new membrane–electrode assemblies of a proton-exchange membrane fuel cell with highly porous electrodes and low Pt loading, based on the proton-conducting polymer Nafion, was characterized in conditions of electrochemical aging. A comprehensive study of the effect of the microstructure on the evolution of the electrochemical characteristics of the new assemblies was obtained by voltammetry, electrochemical impedance spectroscopy, X-ray powder diffraction, and scanning electron microscopy. Because high (>70%) porosity provides intensive mass transfer inside an electrode, structural-modifying additives—long carbon nanotubes—were introduced into the new electrodes. PEM fuel cells with electrodes of a conventional composition without carbon nanotubes were used for comparison. The aging of the samples was carried out according to the standard accelerated method in accordance with the DOE (Department of Energy) protocols. The results show two fundamental differences between the degradation of highly porous electrodes and traditional ones: 1. in highly porous electrodes, the size of Pt nanoparticles increases to a lesser extent due to recrystallization; 2. a more intense “washout” of Nafion and an increase in ionic resistance occur in highly porous electrodes. Mechanisms of the evolution of the characteristics of structurally modified electrodes under electrochemical aging are proposed. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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9 pages, 3107 KiB

Open AccessCommunication

Assessment of Dye-Absorbed Eggshell Membrane Composites as Solid Polymer Electrolyte of Fuel Cells

by Naoki Tanifuji, Takeshi Shimizu, Kentaro Ida, Kosuke Nishio, Miki Tanaka, Yuta Tsukaguchi, Kentaro Tsubouchi, Akihiro Shimizu, Ei-ichi Hino, Yusuke Date, Kaoru Aoki and Hirofumi Yoshikawa

Membranes 2023, 13(1), 115; https://doi.org/10.3390/membranes13010115 - 16 Jan 2023

Cited by 4 | Viewed by 2303

Abstract

Recently, polymer electrolytes have been developed for high-performance and eco-friendly fuel cells. Among the candidates, eggshell membrane (ESM) has been promising because of its abundance to assemble various energy devices with low cost and its absorption ability of organic materials. In this work, [...] Read more.

Recently, polymer electrolytes have been developed for high-performance and eco-friendly fuel cells. Among the candidates, eggshell membrane (ESM) has been promising because of its abundance to assemble various energy devices with low cost and its absorption ability of organic materials. In this work, we investigated fuel cells that included ESM-absorbing xanthene-, triphenylmethane-, and azo-type tar dye, which contained abundant hydrophilic groups, as polymer electrolytes. We found out two points: (1) that the fuel cells that included ESM-absorbing xanthene-type dye generated the highest I–V performance, and (2) the basic molecular structures of the tar dyes determined the correlation of the maximum power and proton conductivities. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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20 pages, 4205 KiB

Open AccessArticle

Composite Proton-Conducting Membrane with Enhanced Phosphoric Acid Doping of Basic Films Radiochemically Grafted with Binary Vinyl Heterocyclic Monomer Mixtures

by Paveswari Sithambaranathan, Mohamed Mahmoud Nasef, Arshad Ahmad, Amin Abbasi and T. M. Ting

Membranes 2023, 13(1), 105; https://doi.org/10.3390/membranes13010105 - 13 Jan 2023

Cited by 7 | Viewed by 2408

Abstract

A composite proton conducting membrane (PCM) was prepared by radiation-induced grafting (RIG) of binary mixtures of 4-vinyl pyridine (4-VP) and 1-vinylimidazole (1-VIm) onto poly(ethylene-co-tetrafluoroethylene) (ETFE) film followed by phosphoric acid (PA) doping. The grafting parameters such as absorbed dose, temperature, monomer [...] Read more.

A composite proton conducting membrane (PCM) was prepared by radiation-induced grafting (RIG) of binary mixtures of 4-vinyl pyridine (4-VP) and 1-vinylimidazole (1-VIm) onto poly(ethylene-co-tetrafluoroethylene) (ETFE) film followed by phosphoric acid (PA) doping. The grafting parameters such as absorbed dose, temperature, monomer concentration, time, and monomer ratio were varied to control the degree of grafting (DG%). The effect of the reactivity ratio of 4-VP and 1-VIm on the composition and degree of monomer unit alternation in the formed graft copolymer was investigated. The changes in the chemical and physical properties endowed by grafting and subsequent PA acid doping were monitored using analytical instruments. The mechanical properties and proton conductivity of the obtained membrane were evaluated and its performance was tested in H₂/O₂ fuel cell at 120 °C under anhydrous and partially wet conditions. The acid doping level was affected by the treatment parameters and enhanced by increasing DG. The proton conductivity was boosted by incorporating the combination of pyridine and imidazole rings originating from the formed basic graft copolymer of 4-VP/1-VIm dominated by 4-VP units in the structure. The proton conductivity showed a strong dependence on the temperature. The membrane demonstrated superior properties compared to its counterpart obtained by grafting 4-VP alone. The membrane also showed a strong potential for application in proton exchange membrane fuel cells (PEMFC) operating at 120 °C. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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13 pages, 2645 KiB

Open AccessArticle

Preparation and Performance Study of the Anodic Catalyst Layer via Doctor Blade Coating for PEM Water Electrolysis

by Gaoyang Liu, Shanlong Peng, Faguo Hou, Xindong Wang and Baizeng Fang

Membranes 2023, 13(1), 24; https://doi.org/10.3390/membranes13010024 - 24 Dec 2022

Cited by 4 | Viewed by 4487

Abstract

The membrane electrode assembly (MEA) is the core component of proton exchange membrane (PEM) water electrolysis cell, which provides a place for water decomposition to generate hydrogen and oxygen. The microstructure, thickness, IrO₂ loading as well as the uniformity and quality of [...] Read more.

The membrane electrode assembly (MEA) is the core component of proton exchange membrane (PEM) water electrolysis cell, which provides a place for water decomposition to generate hydrogen and oxygen. The microstructure, thickness, IrO₂ loading as well as the uniformity and quality of the anodic catalyst layer (ACL) have great influence on the performance of PEM water electrolysis cell. Aiming at providing an effective and low-cost fabrication method for MEA, the purpose of this work is to optimize the catalyst ink formulation and achieve the ink properties required to form an adherent and continuous layer with doctor blade coating method. The ink formulation (e.g., isopropanol/H₂O of solvents and solids content) were adjusted, and the doctor blade thickness was optimized. The porous structure and the thickness of the doctor blade coating ACL were further confirmed with the in-plane and the cross-sectional SEM analyses. Finally, the effect of the ink formulation and the doctor blade thickness of the ACL on the cell performance were characterized in a PEM electrolyzer under ambient pressure at 80 °C. Overall, the optimized doctor blade coating ACL showed comparable performance to that prepared with the spraying method. It is proved that the doctor blade coating is capable of high-uniformity coating. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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25 pages, 7087 KiB

Open AccessArticle

Composite Membranes Based on Functionalized Mesostructured Cellular Foam Particles and Sulfonated Poly(Ether Ether Sulfone) with Potential Application in Fuel Cells

by Natalia A. Agudelo, Claudia E. Echeverri-Cuartas and Betty L. López

Membranes 2022, 12(11), 1075; https://doi.org/10.3390/membranes12111075 - 30 Oct 2022

Cited by 1 | Viewed by 1757

Abstract

Composite polymeric membranes were designed based on sulfonated poly(ether ether sulfone) (sPEES) and mesostructured cellular foam (MCF) silica nanoparticles functionalized with organic compounds. Parameters such as molecular weight (MW) of the polymer, nature of the functional group of the MCF silica, and percentage [...] Read more.

Composite polymeric membranes were designed based on sulfonated poly(ether ether sulfone) (sPEES) and mesostructured cellular foam (MCF) silica nanoparticles functionalized with organic compounds. Parameters such as molecular weight (MW) of the polymer, nature of the functional group of the MCF silica, and percentage of silica charge were evaluated on the final properties of the membranes. Composite membrane characterization was carried out on their water retention capacity (high MW polymer between 20–46% and for the low MW between 20–60%), ion exchange capacity (IEC) (high MW polymer between 0.02 mmol/g–0.07 mmol/g and low MW between 0.03–0.09 mmol/g) and proton conductivity (high MW polymer molecular between 15–70 mS/cm and low MW between 0.1–150 mS/cm). Finally, the membrane prepared with the low molecular weight polymer and 3% wt. of functionalized silica with sulfonic groups exhibited results similar to Nafion^® 117. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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13 pages, 4640 KiB

Open AccessArticle

Carbon-Nanowall Microporous Layers for Proton Exchange Membrane Fuel Cell

by Adriana Elena Balan, Bogdan Ionut Bita, Sorin Vizireanu, Gheorghe Dinescu, Ioan Stamatin and Alexandra Maria Isabel Trefilov

Membranes 2022, 12(11), 1064; https://doi.org/10.3390/membranes12111064 - 29 Oct 2022

Cited by 2 | Viewed by 2527

Abstract

The cathode microporous layer (MPL), as one of the key components of the proton exchange membrane fuel cell (PEM-FC), requires specialized carbon materials to ensure the two-phase flow and interfacial effects. In this respect, we designed a novel MPL based on highly hydrophobic [...] Read more.

The cathode microporous layer (MPL), as one of the key components of the proton exchange membrane fuel cell (PEM-FC), requires specialized carbon materials to ensure the two-phase flow and interfacial effects. In this respect, we designed a novel MPL based on highly hydrophobic carbon nanowalls (CNW). Employing plasma-assisted chemical vapor deposition techniques directly on carbon paper, we produced high-quality microporous layers at a competitive yield-to-cost ratio with distinctive MPL properties: high porosity, good stability, considerable durability, high hydrophobicity, and substantial conductivity. The specific morphological and structural properties were determined by scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Thermo-gravimetric analysis was employed to study the nanostructures’ thermal stability and contact angle measurements were performed on the CNW substrate to study the hydrophobic character. Platinum ink, serving as a fuel cell catalyst, was sprayed directly onto the MPLs and incorporated in the FC assembly by hot-pressing against a polymeric membrane to form the membrane-electrode assembly and gas diffusion layers. Single-fuel-cell testing, at moderate temperature and humidity, revealed improved power performance comparable to industrial quality membrane assemblies (500 mW cm⁻² mg⁻¹ of cathodic Pt load at 80 °C and 80% RH), with elevated working potential (0.99 V) and impeccable fuel crossover for a low-cost system. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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18 pages, 4123 KiB

Open AccessArticle

New Generation of Compositional Aquivion^®-Type Membranes with Nanodiamonds for Hydrogen Fuel Cells: Design and Performance

by Oleg N. Primachenko, Yuri V. Kulvelis, Alexei S. Odinokov, Nadezhda V. Glebova, Anna O. Krasnova, Lev A. Antokolskiy, Andrey A. Nechitailov, Alexander V. Shvidchenko, Iosif V. Gofman, Elena A. Marinenko, Natalia P. Yevlampieva, Vasily T. Lebedev and Alexander I. Kuklin

Membranes 2022, 12(9), 827; https://doi.org/10.3390/membranes12090827 - 24 Aug 2022

Cited by 9 | Viewed by 2483

Abstract

Compositional proton-conducting membranes based on perfluorinated Aquivion^®-type copolymers modified by detonation nanodiamonds (DND) with positively charged surfaces were prepared to improve the performance of hydrogen fuel cells. Small-angle neutron scattering (SANS) experiments demonstrated the fine structure in such membranes filled with [...] Read more.

Compositional proton-conducting membranes based on perfluorinated Aquivion^®-type copolymers modified by detonation nanodiamonds (DND) with positively charged surfaces were prepared to improve the performance of hydrogen fuel cells. Small-angle neutron scattering (SANS) experiments demonstrated the fine structure in such membranes filled with DND (0–5 wt.%), where the conducting channels typical for Aquivion^® membranes are mostly preserved while DND particles (4–5 nm in size) decorated the polymer domains on a submicron scale, according to scanning electron microscopy (SEM) data. With the increase in DND content (0, 0.5, and 2.6 wt.%) the thermogravimetric analysis, potentiometry, potentiodynamic, and potentiotatic curves showed a stabilizing effect of the DNDs on the operational characteristics of the membranes. Membrane–electrode assemblies (MEA), working in the O₂/H₂ system with the membranes of different compositions, demonstrated improved functional properties of the modified membranes, such as larger operational stability, lower proton resistance, and higher current densities at elevated temperatures in the extended temperature range (22–120 °C) compared to pure membranes without additives. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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17 pages, 3052 KiB

Open AccessArticle

Study of MC:DN-Based Biopolymer Blend Electrolytes with Inserted Zn-Metal Complex for Energy Storage Devices with Improved Electrochemical Performance

by Elham M. A. Dannoun, Shujahadeen B. Aziz, Rebar T. Abdulwahid, Sameerah I. Al-Saeedi, Muaffaq M. Nofal, Niyaz M. Sadiq and Jihad M. Hadi

Membranes 2022, 12(8), 769; https://doi.org/10.3390/membranes12080769 - 8 Aug 2022

Cited by 6 | Viewed by 2024

Abstract

Stable and ionic conducting electrolytes are needed to make supercapacitors more feasible, because liquid electrolytes have leakage problems and easily undergo solvent evaporation. Polymer-based electrolytes meet the criteria, yet they lack good efficiency due to limited segmental motion. Since metal complexes have crosslinking [...] Read more.

Stable and ionic conducting electrolytes are needed to make supercapacitors more feasible, because liquid electrolytes have leakage problems and easily undergo solvent evaporation. Polymer-based electrolytes meet the criteria, yet they lack good efficiency due to limited segmental motion. Since metal complexes have crosslinking centers that can be coordinated with the polymer segments, they are regarded as an adequate method to improve the performance of the polymer-based electrolytes. To prepare plasticized proton conducting polymer composite (PPC), a simple and successful process was used. Using a solution casting process, methylcellulose and dextran were blended and impregnated with ammonium thiocyanate and zinc metal complex. A range of electrochemical techniques were used to analyze the PPC, including transference number measurement (TNM), linear sweep voltammetry (LSV), cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The ionic conductivity of the prepared system was found to be 3.59 × 10⁻³ S/cm using the EIS method. The use of glycerol plasticizer improves the transport characteristics, according to the findings. The carrier species is found to have ionic mobility of 5.77 × 10⁻⁵ cm² V⁻¹ s⁻¹ and diffusion coefficient of 1.48 × 10⁻⁶ cm² s⁻¹ for the carrier density 3.4 × 10²⁰ cm⁻³. The TNM revealed that anions and cations were the predominant carriers in electrolyte systems, with an ionic transference value of 0.972. The LSV approach demonstrated that, up to 2.05 V, the film was stable, which is sufficient for energy device applications. The prepared PPC was used to create an electrical double-layer capacitor (EDLC) device. The CV plot exhibited the absence of Faradaic peaks in the CV plot, making it practically have a rectangular form. Using the GCD experiment, the EDLC exhibited low equivalence series resistance of only 65 Ω at the first cycle. The average energy density, power density, and specific capacitance values were determined to be 15 Wh/kg, 350 W/kg, and 128 F/g, respectively. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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12 pages, 21731 KiB

Open AccessArticle

Electrochemical Analysis of Polymer Membrane with Inorganic Nanoparticles for High-Temperature PEM Fuel Cells

by DongWoong Choi

Membranes 2022, 12(7), 680; https://doi.org/10.3390/membranes12070680 - 30 Jun 2022

Cited by 8 | Viewed by 2500

Abstract

In order to solve the challenge that battery performance rapidly deteriorates at a high temperature condition of 100 °C or higher, ZrO₂-TiO₂ (ZT) with various Zr:Ti ratios synthesized by a sol-gel method were impregnated in a Nafion membrane. Through material [...] Read more.

In order to solve the challenge that battery performance rapidly deteriorates at a high temperature condition of 100 °C or higher, ZrO₂-TiO₂ (ZT) with various Zr:Ti ratios synthesized by a sol-gel method were impregnated in a Nafion membrane. Through material characterization, a unique ZT crystal phase peak with a Zr-O-Ti bond was identified, and the band range associated with this bond and intrinsic functional group region could be identified. These prepared powders were blended with 10% (w/w) Nafion-water dispersion to prepare composite Nafion membranes (NZTs). The water uptake increased and the ion exchange capacity decreased as the TiO₂ content increased in the NZTs in which particles were uniformly distributed. These results were superior to those of the conventional Nafion 112. The electrochemical properties of all membranes was measured using a polarization curve in a single cell with a reaction area of 9 cm², and the operating conditions in humidified H₂/air was 120 °C under 50% relative humidity (RH) and 2 atm. The composite membrane cell with nanoparticles of a Zr:Ti ratio of 1:3 (NZT13) exhibited the best electrochemical characteristics. These results can be explained by the improved physicochemical properties of NZT13, such as optimized water content and ion exchange capacity, strong intermolecular forces acting between water and nanofillers (δ), and increased tortuosity by the fillers (τ). The results of this study show that the NZT membrane can replace a conventional membrane under high-temperature and low-humidity conditions. To examine the effect of the content of the inorganic nanomaterials in the composite membrane, a composite membrane (NZT-20, NZT-30) having an inorganic nano-filler content of 20 or 30% (w/w) was also prepared. The performance was high in the order of NZT13, NZT-20, and NZT-30. This shows that not only the operating conditions but also the particle content can significantly affect the performance. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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Review

Jump to: Research

36 pages, 5504 KiB

Open AccessReview

Recent Advanced Synthesis Strategies for the Nanomaterial-Modified Proton Exchange Membrane in Fuel Cells

by Somasundaram Chandra Kishore, Suguna Perumal, Raji Atchudan, Muthulakshmi Alagan, Mohammad Ahmad Wadaan, Almohannad Baabbad and Devaraj Manoj

Membranes 2023, 13(6), 590; https://doi.org/10.3390/membranes13060590 - 9 Jun 2023

Cited by 5 | Viewed by 2931

Abstract

Hydrogen energy is converted to electricity through fuel cells, aided by nanostructured materials. Fuel cell technology is a promising method for utilizing energy sources, ensuring sustainability, and protecting the environment. However, it still faces drawbacks such as high cost, operability, and durability issues. [...] Read more.

Hydrogen energy is converted to electricity through fuel cells, aided by nanostructured materials. Fuel cell technology is a promising method for utilizing energy sources, ensuring sustainability, and protecting the environment. However, it still faces drawbacks such as high cost, operability, and durability issues. Nanomaterials can address these drawbacks by enhancing catalysts, electrodes, and fuel cell membranes, which play a crucial role in separating hydrogen into protons and electrons. Proton exchange membrane fuel cells (PEMFCs) have gained significant attention in scientific research. The primary objectives are to reduce greenhouse gas emissions, particularly in the automotive industry, and develop cost-effective methods and materials to enhance PEMFC efficiency. We provide a typical yet inclusive review of various types of proton-conducting membranes. In this review article, special focus is given to the distinctive nature of nanomaterial-filled proton-conducting membranes and their essential characteristics, including their structural, dielectric, proton transport, and thermal properties. We provide an overview of the various reported nanomaterials, such as metal oxide, carbon, and polymeric nanomaterials. Additionally, the synthesis methods in situ polymerization, solution casting, electrospinning, and layer-by-layer assembly for proton-conducting membrane preparation were analyzed. In conclusion, the way to implement the desired energy conversion application, such as a fuel cell, using a nanostructured proton-conducting membrane has been demonstrated. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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13 pages, 730 KiB

Open AccessReview

Proton-Conducting Polymeric Membranes Based on 1,2,4-Triazole

by Galina F. Prozorova and Alexander S. Pozdnyakov

Membranes 2023, 13(2), 169; https://doi.org/10.3390/membranes13020169 - 29 Jan 2023

Cited by 9 | Viewed by 2218

Abstract

In this review, a comparative analysis of the literature and our own results obtained in the study of the physicochemical, dielectric, and proton-conducting properties of composite polymer materials based on 1H-1,2,4-triazole has been carried out. It has been established that 1 [...] Read more.

In this review, a comparative analysis of the literature and our own results obtained in the study of the physicochemical, dielectric, and proton-conducting properties of composite polymer materials based on 1H-1,2,4-triazole has been carried out. It has been established that 1H-1,2,4-triazole and homopolymers and copolymers of 1-vinyl-1,2,4-triazole are promising for the development of proton-conducting fuel cell membranes. They significantly improve the basic characteristics of electrolyte membranes, increase their film-forming ability, increase thermal stability up to 300–330 °C, increase the electrochemical stability region up to 3–4 V, promote high mechanical strength and morphological stability of membranes, and provide high ionic conductivity (up to 10⁻³–10⁻¹ S/cm) under anhydrous conditions at temperatures above 100 °C. There is also an improvement in the solubility and a decrease in the glass transition temperature of polymers based on 1-vinyl-1,2,4-triazole, which facilitates the processing and formation of membrane films. The results obtained demonstrate the uniqueness of 1H-1,2,4-triazole and (co)polymers based on 1-vinyl-1,2,4-triazole and the promise of their use for the creation of heat-resistant plastic and electrochemically stable, mechanically strong proton-conducting membranes with high ionic conductivity under anhydrous conditions and at high temperatures. Full article

(This article belongs to the Special Issue Proton-Conducting Membranes)

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