scholarly journals Development of a Chitosan/PVA/TiO2 Nanocomposite for Application as a Solid Polymeric Electrolyte in Fuel Cells

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1691 ◽  
Author(s):  
Elio Enrique Ruiz Gómez ◽  
José Herminsul Mina Hernández ◽  
Jesús Evelio Diosa Astaiza
Keyword(s):  
Proton Exchange Membrane ◽  
Moisture Absorption ◽  
Complex Impedance ◽  
Open Circuit ◽  
Proton Exchange ◽  
Polymeric Electrolyte ◽  
Thermal Transitions ◽  
Scanning Calorimetry ◽  
Current Test ◽  
Solid Polymeric Electrolyte

The influence of the incorporation of nanoparticles of titanium oxide (TiO2) at a concentration between 1000 and 50,000 ppm on the physicochemical and mechanical properties of a polymer matrix formed from a binary mixture of chitosan (CS) and polyvinyl alcohol (PVA) at a ratio of 80:20 and the possibility of its use as a solid polymeric electrolyte were evaluated. With the mixture of the precursors, a membrane was formed with the solvent evaporation technique (casting). It was found that the incorporation of the nanoparticles affected the moisture absorption of the material; the samples with the highest concentrations displayed predominantly hydrophobic behavior, while the samples with the lowest content displayed absorption values of 90%. Additionally, thermogravimetric analysis (TGA) showed relatively low dehydration in the materials that contained low concentrations of filler; moreover, differential scanning calorimetry (DSC) showed that the nanoparticles did not significantly affect the thermal transitions (Tg and Tm) of the compound. The ionic conductivity of the compound with a relatively low concentration of 1000 ppm TiO2 nanoparticles was determined by complex impedance spectroscopy. The membranes doped with a 4 M KOH solution demonstrated an increase in conductivity of two orders of magnitude, reaching values of 10−6 S·cm−1 at room temperature in previously dried samples, compared to that of the undoped samples, while their activation energy was reduced by 50% with respect to that of the undoped samples. The voltage–current test in a proton exchange membrane fuel cell (PEMFC) indicated an energy efficiency of 17% and an open circuit voltage of 1.0 V for the undoped compound, and these results were comparable to those obtained for the commercial membrane product Nafion® 117 in evaluations performed under conditions of 90% moisture saturation. However, the tests indicated a low current density in the undoped compound.

Performance decay of proton-exchange membrane fuel cells under open circuit conditions induced by membrane decomposition

2009 ◽  
Vol 187 (2) ◽  
pp. 324-331 ◽  
Author(s):  
Seiho Sugawara ◽  
Takao Maruyama ◽  
Yoshiki Nagahara ◽  
Shyam S. Kocha ◽  
Kazuhiko Shinohra ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Open Circuit ◽  
Proton Exchange ◽  
Exchange Membrane

A Model of a High-Temperature Direct Methanol Fuel Cell

2013 ◽  
Vol 10 (5) ◽  
Author(s):  
K. Scott ◽  
S. Pilditch ◽  
M. Mamlouk
Keyword(s):  
Fuel Cell ◽  
Direct Methanol Fuel Cell ◽  
Proton Exchange Membrane ◽  
Open Circuit ◽  
Proton Exchange ◽  
Cell Performance ◽  
Effect Of Temperature ◽  
Fuel Cell Performance ◽  
Direct Methanol ◽  
Methanol Fuel Cell

A steady-state, isothermal, one-dimensional model of a direct methanol proton exchange membrane fuel cell (PEMFC), with a polybenzimidazole (PBI) membrane, was developed. The electrode kinetics were represented by the Butler–Volmer equation, mass transport was described by the multicomponent Stefan–Maxwell equations and Darcy's law, and the ionic and electronic resistances described by Ohm's law. The model incorporated the effects of temperature and pressure on the open circuit potential, the exchange current density, and diffusion coefficients, together with the effect of water transport across the membrane on the conductivity of the PBI membrane. The influence of methanol crossover on the cathode polarization is included in the model. The polarization curves predicted by the model were validated against experimental data for a direct methanol fuel cell (DMFC) operating in the temperature range of 125–175 °C. There was good agreement between experimental and model data for the effect of temperature and oxygen/air pressure on cell performance. The fuel cell performance was relatively poor, at only 16 mW cm−2 peak power density using low concentrations of methanol in the vapor phase.

scholarly journals Polymer Electrolyte Membranes Based on Nafion and a Superacidic Inorganic Additive for Fuel Cell Applications

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 914 ◽  
Author(s):  
Lucia Mazzapioda ◽  
Stefania Panero ◽  
Maria Assunta Navarra
Keyword(s):  
Fuel Cell ◽  
Ion Exchange ◽  
Proton Exchange Membrane ◽  
Sol Gel ◽  
Composite Membranes ◽  
Exchange Capacity ◽  
Proton Exchange ◽  
Thermal Transitions ◽  
Ion Exchange Capacity ◽  
Electrolyte Membranes

Nafion composite membranes, containing different amounts of mesoporous sulfated titanium oxide (TiO2-SO4) were prepared by solvent-casting and tested in proton exchange membrane fuel cells (PEMFCs), operating at very low humidification levels. The TiO2-SO4 additive was originally synthesized by a sol-gel method and characterized through x-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and ion exchange capacity (IEC). Peculiar properties of the composite membranes, such as the thermal transitions and ion exchange capacity, were investigated and here discussed. When used as an electrolyte in the fuel cell, the composite membrane guaranteed an improvement with respect to bare Nafion systems at 30% relative humidity and 110 °C, exhibiting higher power and current densities.

Self-Assembly Proton Exchange Membranes for Direct Methanol Fuel Cell with Size-Controlled Au Nanoparticles

2011 ◽  
Vol 306-307 ◽  
pp. 108-111
Author(s):  
Ai Ping Jin ◽  
Zhao Hui Wan ◽  
Kai Chen Lei
Keyword(s):  
Self Assembly ◽  
Proton Exchange Membrane ◽  
Au Nanoparticles ◽  
Membrane Surface ◽  
Open Circuit ◽  
Proton Exchange ◽  
Membrane Area ◽  
Membrane Conductivity ◽  
Self Assembled ◽  
And Performance

Charged Au nanoparticles with various diameters, from 2.7 nm to 10.3 nm, were synthesized by using various reducing agents. Then charged Au nanoparticles were self-assembled onto the NafionTM membrane surface as methanol barriers. It was found that the proton exchange membrane self-assembled with 3.9 nm Au particles had the lowest methanol crossover. The proton conductivity decreased with the increase of the particles size until the particles size was more than 6.2 nm and they had little influence on the membrane conductivity. All the self-assembled membranes have higher open circuit voltage (OCV) and performance than original Nafion212TM membrane. And the membranes self-assembled with 3.9 nm poly (diallymethylammonium chloride) (PDDA) modified Au (PDDA-Au) particles had the highest performance due to the reciprocal of the methanol permeation current density and membrane area resistance.

scholarly journals Membrane Electrolyte Assembly Health Estimation Method for Proton Exchange Membrane Fuel Cells

2017 ◽  
Vol 14 (4) ◽  
Author(s):  
Alexander J. Headley ◽  
Martha Gross ◽  
Dongmei Chen
Keyword(s):  
Proton Exchange Membrane ◽  
Membrane Surface ◽  
Computational Cost ◽  
Estimation Method ◽  
Cell Voltage ◽  
Open Circuit ◽  
Proton Exchange ◽  
Normal Operation ◽  
Degradation Rates ◽  
Exchange Membrane

Membrane electrolyte assembly (MEA) aging is a major concern for deployed proton exchange membrane (PEM) fuel cell stacks. Studies have shown that working conditions, such as the operating temperature, humidity, and open circuit voltage (OCV), have a major effect on degradation rates and also vary significantly from cell to cell. Individual cell health estimations would be very beneficial to maintenance and control schemes. Ideally, estimations would occur in response to the applied load to avoid service interruptions. To this end, this paper presents the use of an extended Kalman filter (EKF) to estimate the effective membrane surface area (EMSA) of each cell using cell voltage measurements taken during operation. The EKF method has a low computational cost and can be applied in real time to estimate the EMSA of each cell in the stack. This yields quantifiable data regarding cell degradation. The EKF algorithm was applied to experimental data taken on a 23-cell stack. The load profiles for the experiments were based on the FTP-75 and highway fuel economy test (HWFET) standard drive cycle tests to test the ability of the algorithm to perform in realistic load scenarios. To confirm the results of the EKF method, low performing cells and an additional “healthy” cell were selected for scanning electron microscope (SEM) analysis. The images taken of the cells confirm that the EKF accurately identified problematic cells in the stack. The results of this study could be used to formulate online sate of health estimators for each cell in the stack that can operate during normal operation.

scholarly journals An Investigation of Proton Conductivity of Vinyltriazole-Grafted PVDF Proton Exchange Membranes Prepared via Photoinduced Grafting

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Sinan Sezgin ◽  
Deniz Sinirlioglu ◽  
Ali Ekrem Muftuoglu ◽  
Ayhan Bozkurt
Keyword(s):  
Proton Conductivity ◽  
High Performance ◽  
Proton Exchange Membrane ◽  
Vinylidene Fluoride ◽  
Uv Light ◽  
Stability Domain ◽  
Proton Exchange ◽  
Triflic Acid ◽  
Scanning Calorimetry ◽  
Electrolyte Membranes

Proton exchange membrane fuel cells (PEMFCs) are considered to be a promising technology for clean and efficient power generation in the twenty-first century. In this study, high performance of poly(vinylidene fluoride) (PVDF) and proton conductivity of poly(1-vinyl-1,2,4-triazole) (PVTri) were combined in a graft copolymer, PVDF-g-PVTri, by the polymerization of 1-vinyl-1,2,4-triazole on a PVDF based matrix under UV light in one step. The polymers were doped with triflic acid (TA) at different stoichiometric ratios with respect to triazole units and the anhydrous polymer electrolyte membranes were prepared. All samples were characterized by FTIR and1H-NMR spectroscopies. Their thermal properties were examined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA demonstrated that the PVDF-g-PVTri and PVDF-g-PVTri-(TA)x membranes were thermally stable up to 390°C and 330°C, respectively. NMR and energy dispersive X-ray spectroscopy (EDS) results demonstrated that PVDF-g-PVTri was successfully synthesized with a degree of grafting of 21%. PVDF-g-PVTri-(TA)3showed a maximum proton conductivity of6×10-3 Scm−1at 150°C and anhydrous conditions. CV study illustrated that electrochemical stability domain for PVDF-g-PVTri-(TA)3extended over 4.0 V.

scholarly journals Research on Flexible Thin-Disk Glucose Biofuel Cells Based on Single-Walled Carbon Nanotube Electrodes

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Yingying Li ◽  
Wei Xiong ◽  
Cheng Zhang ◽  
Xing Yang
Keyword(s):  
Proton Exchange Membrane ◽  
Direct Electron Transfer ◽  
Economic Benefits ◽  
Open Circuit ◽  
Proton Exchange ◽  
Biofuel Cell ◽  
Promising Alternative ◽  
Practical Applications ◽  
Single Walled Carbon ◽  
Biological Compatibility

Glucose biofuel cell (GBFC) is a power supply device which has attracted considerable attention because of its green environmental protection and high economic benefits. Fuels like glucose and oxygen are ubiquitous in physiological fluids, allowing the direct harvest of energy from human bodies. Compared with conventional batteries such as Li-Po, GBFC is a more promising alternative to power medical devices without the need to be replaced or refueled. However, the energy conversion efficiency of the existing GBFCs still needs to be further improved for practical applications. In this paper, the performance of the GBFC was studied based on single-walled carbon nanotubes (SWCNTs), which have relatively high conductivity and large specific surface area that could improve the activity of enzymes immobilized on the electrode surface and thus realize the direct electron transfer (DET). After optimization of the catalysts’ amount, the GBFC based on SWCNTs performed well with two Pt layers sprayed on one side of the proton exchange membrane (PEM) and 1.5 mL glucose oxidase (GOx) dropped on the other side, which attained the highest open-circuit potential (OCP) of 0.4 V. After being encapsulated with a flexible porous enclosure made by polydimethylsiloxane (PDMS), the biological compatibility of the completed GBFC has been successfully improved, which provides great potential for powering wearable or implantable devices.

Effect of Temperature on Electricity Generation of Single-Chamber Microbial Fuel Cells with Proton Exchange Membrane

2011 ◽  
Vol 393-395 ◽  
pp. 1169-1172 ◽  
Author(s):  
Yu Lan Tang ◽  
Ya Ting He ◽  
Peng Fei Yu ◽  
Hong Sun ◽  
Jin Xiang Fu
Keyword(s):  
Microbial Activity ◽  
Power Density ◽  
Microbial Fuel Cells ◽  
Proton Exchange Membrane ◽  
Open Circuit Voltage ◽  
Phosphate Buffer Solution ◽  
Open Circuit ◽  
Proton Exchange ◽  
Single Chamber ◽  
Exchange Membrane

The effects of temperature on electricity performance and microbial activity were investigated in single-chamber microbial fuel cell with proton exchange membrane (S-PEM-MFC) using glucose as substrate with phosphate buffer solution(PBS). The results showed that S-PEM-MFC able to adapt to a wide temperature range of 11, 18, 25, 30 and 35°C. The open circuit voltage, polarization, power density and microbial activity of S-PEM-MFC were increased with increasing temperature from 11 to 30°C. The maximum power density were 193.8mW∙m-3 at 30°C. Compared to 30°C, the battery open circuit voltage increased by only 4.8% at 35°C, while the polarization and power density is almost the same. These results demonstrate that according to the principle of economy which 30°C should be the optimal operating temperature of S-PEM-MFC.

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