Changman Kim, Young Eun Song, Cho Rong Lee et al.

Journal of Industrial Microbiology and Biotechnology • 2016

Abstract Glycerol is an attractive feedstock for bioenergy and bioconversion processes but its use in microbial fuel cells (MFCs) for electrical energy recovery has not been investigated extensively. This study compared the glycerol uptake and electricity generation of a co-culture of Shewanella oneidensis MR-1 and Klebsiella pneumonia J2B in a MFC with that of a single species inoculated counterpart. Glycerol was metabolized successfully in the co-culture MFC (MFC-J&M) with simultaneous electricity production but it was not utilized in the MR-1 only MFC (MFC-M). A current density of 10 mA/m2 was obtained while acidic byproducts (lactate and acetate) were consumed in the co-culture MFC, whereas they are accumulated in the J2B-only MFC (MFC-J). MR-1 was distributed mainly on the electrode in MFC-J&M, whereas most of the J2B was observed in the suspension in the MFC-J reactor, indicating that the co-culture of both strains provides an ecological driving force for glycerol utilization using the electrode as an electron acceptor. This suggests that a co-culture MFC can be applied to electrical energy recovery from glycerol, which was previously known as a refractory substrate in a bioelectrochemical system.

Zarar Ahmed, Tehmoor Ellahi, Alin Ciobica et al.

International Journal of Energy Research • 2024

Energy crisis and wastewater treatment are critical global issues. In this study, a novel separator was made by boiling cotton rope with solutions of various salts and their concentrations. It was then employed in a dual‐chamber microbial fuel cell (MFC) to treat municipal wastewater collected from 25 Area Wah Cantt, Punjab, Pakistan. Batch scale experiments were carried out to evaluate the effect of various variables, that is, different salts (NaCl, KCl, and MgCl 2 ) and their concentrations (0.2, 0.5, and 1 M) used in separator, wastewater volume (50, 500, and 1000 mL), and aluminum mesh thickness (0.6, 0.8, and 1 mm) on MFC performance in terms of current generation and wastewater treatment for 7 days. Analysis of collected wastewater showed that among the six studied physicochemical parameters, only two, that is, biological oxygen demand (BOD) and chemical oxygen demand (COD) were above the permissible limits of National Environmental Quality Standards (NEQS). Results after MFC experiments showed that separator containing 0.5 M NaCl produced a significantly ( p < 0.05) high current of 68.16 µA as compared to the other studied salts and their concentrations, whereas COD and BOD were reduced up to 124.15 and 62.12 mg L −1 , respectively. A wastewater volume of 1000 mL generated a significantly ( p < 0.05) high current of 83.41 µA compared to the other studied volumes, where COD and BOD residual values were 123.25 and 59.56 mg L −1 , respectively. An aluminum mesh thickness of 1 mm produced a significantly ( p < 0.05) high current of 103 µA, while 120.89 and 68.93 mg L −1 were achieved COD and BOD values, respectively. It was concluded that MFC performance was enhanced with an increase in wastewater volume and mesh thickness. Therefore, it is recommended that further pilot‐scale continuous studies be carried out to implement this research on a larger scale.

Mbugua J K, Kinyua A, Mbui D N et al.

American Journal of Environment and Climate • 2022

In microbial fuel cell technology, the substrate is consumed by microbes in anaerobic conversion of substrate to electricity. Bio-remediation of pollutants involves microbial environmental cleanup using green approach. The primary problems with pesticides are linked to the non-negligible proportion of the sprayed active ingredient that does not reach its intended target thereby contaminating environmental compartments persistently. The primary objective of this study was to assess the potential of microbial fuel cell technology in bio-remediation of lambda cyahlothrin, chlorpyrifos and malathion in Limuru loam soil. H-shaped double chamber microbial fuel cell was fabricated where the anodic chamber was loaded with 750 mL loam soil inoculated with 750 mL bio-slurry doped with 10 mL of 10 ppm lambda cyhalothrin, chlorpyrifos and malathion pesticide solutions. The cathodic chamber was loaded with 1500 mL distilled water. The setup was incubated for a 90 days retention time where voltage and current were recorded daily using a multi-meter. The degradation level was assessed using a GC-MS after sample extraction using standard QuEChERs method. The voltage generated from the pesticide doped loam soil showed an upward trend from day 0 to day 15 in lambda cyhalothrin and malathion and from day 0 to day 20 in chlorpyrifos and pesticide mixture after which constant readings were observed for three days with downward trends thereafter. The maximum generated voltage was 0.537 V, 0.571 V, 0.572 V and 0.509 V in chlorpyrifos, lambda cyhalothrin, malathion and pesticide mix (MCL) respectively. The bioremediation levels for chlorpyrifos and malathion were 65.80 % and 71.32 %, respectively while no detectable, lambda cyhalothrin was observed after day 60 of the study. This study concludes that bioremediation of lambda cyhalothrin, chlorpyrifos and malathion in Limuru loam soil can be achieved using microbial fuel cells.

M. Z. M. Muaz, R. Abdul, V. M. Vadivelu

Environmental Progress & Sustainable Energy • 2018

Microbial fuel cells (MFC) haves drawn much attention as a potential approach for sludge treatment and renewable energy production. In this study, a single chamber air‐cathode in a membrane‐less MFC (ML‐MFC) was operated in batch mode with dewatered sludge from a municipal wastewater treatment plant as the substrate. Electrogenic bacterial species in the sludge acted as a catalyst for the generation of electricity. The performance of the ML‐MFC was evaluated using one‐factor‐at‐a‐time (OFAT) method followed by response surface methodology (RSM) via Central Composite Design using a quadratic model. In the preliminary OFAT study, the highest voltage generation (852.7 mV) and COD removal (149.2 mg/L) were obtained when the pH, electrode distance, moisture content, and temperature were at 6.0, 3 cm, 30% (vol/wt), and 35°C, respectively. After incubation of the ML‐MFC using optimum conditions suggested by the RSM, the voltage was successfully increased to 927.7 mV (improved 9%), while COD removal increased to 170.8 mg/L (improved 15%). This showed that optimization using RSM gave better results than the OFAT method. The maximum power density recorded from the optimum conditions was 41.3 mW/m 2 . © 2018 American Institute of Chemical Engineers Environ Prog, 38: 208–219, 2019

Khaya Pearlman Shabangu, Manimagalay Chetty, Babatunde Femi Bakare

Energies • 2024

Microbial fuel cells (MFCs) have garnered significant attention due to their capacity to generate electricity using renewable and carbon-neutral energy sources such as wastewater. Extensive experimental work and modeling techniques have been employed to dissect these processes and understand their respective impacts on electricity generation. The driving force is to enhance MFC performance for practical applications commercially. Among the various statistical modeling approaches, one particularly robust tool is the Design of Experiments (DoE). It serves to establish the relationships between different variables that influence MFC performance and allows for the optimization of the MFC configuration and operation for scaled-up performances in terms of bioelectricity generation. This study focused on optimizing microbial fuel cells (MFCs) for bioelectricity production using industrial wastewater treatment, employing the Box–Behnken design (BBD) methodology. Through an analysis of response surface models and ANOVA tests, it was found that a combined approach of reduced quadratic, reduced two-factor interaction, and linear models yielded sound results, particularly in voltage yield, COD removal, and current density. Second-order regression models predicted optimal conditions for various parameters, with surface area, temperature, and catholyte dosage identified as critical input variables for optimization. Under these conditions, conducted by the four-factor and three-level Box–Behnken design methodology in a double-chamber MFC unit considering eight output variables—CCV yield, % COD removal, current density, power density, % TSS removal, % CE, and % PO43−—the optimum values were 700 mV, 54.4%, 54.4 mA/m2, 73.7 mW/m2, 99%, 21.2%, and 100%, respectively. At optimum operating conditions, the results revealed a desirability of 76.6% out of a total of 92 iterations. The paper highlights the effectiveness of statistical ANOVA fit-statistics modeling and optimization in enhancing DCMFC performance, recommending its use as a sustainable bioenergy source. Furthermore, validation results supported the above optimization output response findings and confirmed the viability of biorefinery wastewater as an anolyte for scaling up DCMFC bioelectricity generation.

A A Fedotov, A B Tarasenko, D A Karanova

Journal of Physics: Conference Series • 2020

Abstract The gas diffusion layer (GDL) plays an important role in the operation of fuel cells with a proton exchange membrane (PEMFC). GDL is commonly used on three possible types of carbon fiber-con backing: carbon fabric, non-woven material, carbon paper. All three types have different properties, such as gas permeability, mechanical strength, electrical resistance, hydrophilicity and price. Paper is much cheaper than non-woven material, and replacing even one electrode could make a fuel cell cheaper. But replacement makes sense only if the same efficiency is maintained. In this work, two types of GDL as an anode in PEMFC were compared. As a result of the comparison, current-voltage and power characteristics were obtained.

E. Pichot, M. Olivon, A. Perraud et al.

Fuel Cells • 2020

Abstract A Ni/Yttria‐stabilized zirconia (YSZ) cell with a (La 0.60 Sr 0.40 ) 0.95 Co 0.20 Fe 0.80 O 3– δ cathode is tested both in fuel cell and electrolysis modes. In fuel cell mode under dry air and wet H 2 , the cell is operated between the open circuit voltage (OCV) and 0.4 V and reaches 330 mW cm −2 at 850 °C for 157 mL min −1 H 2 supply. The influence of temperature and air or hydrogen flow rate is studied, and impedance measurements show that below 0.8 V the electrolyte becomes the more resistive part of the cell. Nevertheless, fuel utilization yields are higher under oxygen or hydrogen depletion. If it is possible at 750 °C to work at low voltage during several hours in the entire voltage range, the voltage decrease must be limited at 850 °C. The cell can also be operated under wet air. The same cell can be operated in electrolysis mode, and a power density of 340 mW cm −2 can be obtained at 0.3 V/OCV under 100 mL min −1 wet (3% H 2 O) 5% H 2 –95% Ar mixture on the fuel side and dry or wet 100 mL min −1 air flow on the air side. Nevertheless, bubbling air providing the air electrode in saltwater has an irreversible detrimental effect on the cell.

Kiran K. Jayaraj, Prakash Saravanan, Gourav Dhar Bhowmick

Energies • 2023

The sustainable development of aquaculture faces a significant challenge due to the need for the frequent treatment of aquacultural waste. This research presents a pioneering solution by concurrently utilizing aquacultural waste to produce biochar and enhancing a sediment microbial fuel cell (SMFC)’s treatment efficacy for waste generated from the integrated multitrophic aquaculture (IMTA) system. The water quality parameters of the aquacultural pond water were analyzed, and synthetic wastewater was prepared to validate the system’s efficiency. Over a period of more than 50 days, the SMFC was operated and monitored, yielding an average chemical oxygen demand (COD) removal efficiency of 86.31 ± 2.18%. The maximum operating voltage of the SMFC reached 0.422 V on the 21st day of operation when connected to an external resistance of 975 Ω. A novel-activated aquacultural biochar catalyst was synthesized from aquaponics waste and used as a cathode catalyst, substantially improving the SMFC’s performance. Characterization studies demonstrated that the aquacultural biochar catalyst was an active electrocatalyst, accelerating the oxygen reduction reaction rate and leading to increased power output and overall efficiency of the SMFC. The SMFC utilizing the aquacultural-waste-based biochar cathode catalyst showcased the highest maximum power density, with a range of 101.63 mW/m2 (1693.83 mW/m3), and the lowest internal resistance, indicating superior performance. These results validate the reliability of implementing SMFCs in actual aquaculture systems. A novel modular design for SMFC reactor-assisted small-scale integrated poultry–fish culture systems is proposed for further practical application in real-life aquaculture settings. This research contributes to finding sustainable and effective methods for waste treatment for aquaculture, promoting the development of environmentally friendly practices in the industry.

Enas Taha Sayed, Hussain Alawadhi, Khaled Elsaid et al.

Sustainability • 2020

Microbial fuel cell (MFC) is an emerging method for extracting energy from wastewater. The power generated from such systems is low due to the sluggish electron transfer from the inside of the biocatalyst to the anode surface. One strategy for enhancing the electron transfer rate is anode modification. In this study, iron nanostructure was synthesized on a carbon cloth (CC) via a simple electroplating technique, and later investigated as a bio-anode in an MFC operated with real wastewater. The performance of an MFC with a nano-layer of iron was compared to that using bare CC. The results demonstrated that the open-circuit voltage increased from 600 mV in the case of bare CC to 800 mV in the case of the iron modified CC, showing a 33% increase in OCV. This increase in OCV can be credited to the decrease in the anode potential from 0.16 V vs. Ag/AgCl in the case of bare CC, to −0.01 V vs. Ag/AgCl in the case of the modified CC. The power output in the case of the modified electrode was 80 mW/m2—two times that of the MFC using the bare CC. Furthermore, the steady-state current in the case of the iron modified carbon cloth was two times that of the bare CC electrode. The improved performance was correlated to the enhanced electron transfer between the microorganisms and the iron-plated surface, along with the increase of the anode surface- as confirmed from the electrochemical impedance spectroscopy and the surface morphology, respectively.

Tianyi Yang, Song Xue, Liming Jiang et al.

Coatings • 2025

Microbial fuel cells (MFCs) generate electricity through the microbial oxidation of organic waste. However, the inherent electrochemical performance of carbon felt (CF) electrodes is relatively poor and requires enhancement. In this study, nickel oxide (NiO) was successfully loaded onto CF to improve its electrode performance, thereby enhancing the electricity generation capacity of MFCs during the degradation of treated wastewater. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy diffusion spectrometer (EDS) analyses confirmed the successful deposition of NiO on the CF surface. The modification enhanced both the conductivity and capacitance of the electrode and increased the number of microbial attachment sites on the carbon fiber filaments. The prepared CF–NiO electrode was employed as the anode in an MFC, and its electrochemical and energy storage performance were evaluated. The maximum power density of the MFC with the CF–NiO anode reached 0.22 W/m2, compared to 0.08 W/m2 for the unmodified CF anode. Under the C1000-D1000 condition, the charge storage capacity and total charge output of the CF–NiO anode were 1290.03 C/m2 and 14,150.03 C/m2, respectively, which are significantly higher than the 452.9 C/m2 and 6742.67 C/m2 observed for the CF anode. These results indicate notable improvements in both power generation and energy storage performance. High-throughput gene sequencing of the anodic biofilm following MFC acclimation revealed that the CF–NiO anode surface hosted a higher proportion of electroactive bacteria. This suggests that the NiO modification enhances the biodegradation of organic matter and improves electricity generation efficiency.

Biraj Kumar Kakati, Avijit Ghosh, Anil Verma

ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology • 2010

Composite bipolar plates for polymer electrolyte membrane fuel cell (PEMFC) were developed by compression molding technique using vinyl ester resin as a binder and natural graphite, carbon black, and carbon fiber as conductive reinforcements. The developed bipolar plates were characterized for electrical conductivity, flexural strength, deflection at mid-span, hydrogen permeability, and morphology. The in-plane and through-plane electrical conductivities of the composite bipolar plate (VER:25%;CB:5%;CF:5%;NG:65%) were 355.05 and 95.96 S·cm−1, respectively. The flexural strength of the same bipolar plate was 53.50 MPa with a deflection of 5.37%. The hydrogen permeability of the bipolar plate was in the order of 10−9 cm3·cm−1·s−1 at 50°C. The overall properties of the composite bipolar plate were found to achieve the benchmark set by USA-Department of Energy. However, the through-plane electrical conductivity of the above composite was edge below the target value. Therefore, graphene, being one of the most electrical conductive materials, has been reinforced into the composite bipolar plate. The results were very encouraging as 1% graphene reinforcement increased the in-plane and through-plane electrical conductivities of the bipolar plate by around 6 and 35%, respectively. The performance of a PEMFC was evaluated using the developed bipolar plate in in-situ condition.

Tatyana V. Reshetenko, Guenter Randolf, Madeleine Odgaard et al.

ECS Meeting Abstracts • 2020

The most promising alternative to Platinum Group Metals (PGMs) Oxygen Reduction Reaction (ORR) catalysts for proton exchange membrane fuel cell (PEMFC) applications is a class of electrocatalysts consisting of atomically dispersed transition metals (Fe and Mn) in a matrix of carbon and nitrogen, so called M-N-C materials [1]. Currently, the emerging novel M-N-C materials demonstrated 30% of PGM catalyst activity [1]. Performance of PGM-free electrocatalysts can be improved by increasing density of M-Nx sites or optimizing their accessibility through proper integration into the triple phase catalyst layer in a membrane electrode assembly (MEA). Since overall MEA’s performance depends on properties of all its components: membrane, electrodes and gas diffusion layers (GDL), it is important to understand impact of these materials on PGM-free fuel cell operation. In this work we report effects of membrane thickness on performance of PGM-free PEMFCs using various electrochemical methods and modelling. The commercial, PGM-free electrocatalyst manufactured by Pajarito Powder and marketed as PMF-011904 was used in the present study. Catalyst coated membranes with active area of 23 cm 2 were manufactured by IRD Fuel Cell by their proprietary digital printing method. For this work we used membranes with thickness of 15 (LYT0008), 25 (N211), 125 (N115) and 175 (N117) μm. The cathode PGM-free catalyst loading was 6.0 mg cm -2 , while anode employed Pt/C catalyst with loading of 0.2 mg Pt cm -2 . Freudenberg H23C8 GDLs were applied for both electrodes. Electrochemical evaluation of PGM–free MEAs was performed using a custom test station, designed at the HNEI and characterized by dynamic response time <0.1 s. The anode and cathode were fed with H 2 and O 2 respectively, at constant flow rates of 0.5 slpm at 100% relative humidity and 150 kPa absolute backpressure for both electrodes, and the cell temperature was 80°C. Fig. 1 a) shows a representative SEM image of the MEA cross-section. The cathode thickness was found to be 140-160 μm for all samples. The IV data clearly showed that an increase in the membrane thickness led to an increase of HFR and caused poor performance (Fig. 1 b). The highest performance was achieved for MEAs with thin membranes 15 and 25 μm. At the same time application of thick membrane allowed us to reach the highest ocv values 0.979 V (175 μm) vs 0.929 V (15 μm). The impedance data were analyzed using physics-based model which includes proton and oxygen transport in the cathode layer [2]. The results demonstrated a rapid decay of proton conductivity from 15-18 to 5-10 mS cm -1 at current densities higher than 100 mA cm -2 . Possible mechanism of the observed decay can be attributed to dissolution of Fe-N-C centers and formation of Fe 3+ cations which reduce ionomer conductivity by screening SO 3- groups [3-4]. Due to relatively low proton conductivity and large electrode thickness, the ORR rate is strongly non–uniform through the cathode depth. Our estimates showed that this non-uniformity leads to 2 K overheat of the catalyst layer at the membrane surface. The overheat could induce pressure gradient, pushing liquid water out of the electrode and clearing void pores for gaseous transport of oxygen. This mechanism might explain explosive growth of the cathode oxygen diffusivity (5-7⋅10 -3 cm 2 s -1 ). Detailed analyses of the PGM-free PEMFC performance and its correlation with AC-impedance results will be presented and discussed. Acknowledgments We gratefully acknowledge funding from ONR (N00014-19-1-2159) and DOE EERE (DE-EE0008419). The authors are thankful to T. Carvalho for assisting with SEM. Reference 1. S.T. Thompson, A.R. Wilson, P. Zelenay, D.J. Myers, K.L. More, K.C. Neyerlin, D. Papageorgopoulos, Solid State Ionics 319 , 68-69 (2018). 2. A. Kulikovsky, J. Electroanal. Chem . 669 , 28-34 (2012). 3. T. Reshetenko, G. Randolf, M. Odgaard, B. Zulevi, A. Serov, A. Kulikovsky, J. Electrochem. Soc. 167 , 084501 (2020). 4. T. Reshetenko, A. Serov, A. Kulikovsky, P. Atanassov, J. Electrochem. Soc. 166 , F653-F660 (2019). Figure 1

Kea-Lee Yap, Li-Ngee Ho, Soon-An Ong et al.

IOP Conference Series: Earth and Environmental Science • 2020

Abstract Microbial fuel cell (MFC) is a promising and sustainable technology that has high efficiency to produce renewable energy and treat wastewater simultaneously. The effect of carbon materials on the removal of synthetic wastewater in the anodic chamber and electricity generation were investigated using a double chambered MFC. In this study, a double chambered reactor made up of anodic and cathodic chambers separated by proton exchange membrane has been developed. Carbon plate and carbon felt were characterized using scanning electron microscopy. Results revealed that 1.20 times higher chemical oxygen demand removal of synthetic wastewater using carbon felt (50.90%) as compared with that of carbon plate (43.52%). The maximum voltage output produced by carbon felt (280.20 mV) was 20.70% higher than carbon plate (222.20 mV) as cathode in MFC. The surface morphology of carbon materials has significant effect on the oxygen reduction reaction reactivity at cathodic chamber.

Changman Kim, Jung Rae Kim, Jinhee Heo

Journal of Chemical Technology & Biotechnology • 2019

Abstract BACKGROUND Microbial fuel cells (MFCs) are promising devices that can be used to generate electricity from organic wastewater through microbial redox reactions. Various strategies have been attempted to improve the power generation of MFCs, including electrode modification. Titanium (Ti) is a biocompatible metal which is commonly used in various applications. This study examined the improvement of voltage generation by Ti nanoparticle attachment to the carbon electrode surface of an MFC by simple dipping and e‐beam evaporation. Two microbes, namely Shewanella oneidensis MR‐1 and Klebsiella pneumoniae L17, having different electron transfer mechanisms were used to identify the effects of Ti nanoparticles on bioelectricity generation. RESULTS Voltage generation was significantly increased for the MFCs containing Ti nanoparticles, both using S. oneidensis MR‐1 and K. pneumoniae L17. Higher concentrations of DNA extracted from the electrode surface indicated that the Ti nanoparticles did not only assist the electron transfer process from the bacteria to the electrode but also microbial attachment on the carbon electrode. Energy‐dispersive X‐ray spectroscopy (EDS) experiments demonstrated the sustainability of the Ti nanoparticles, showing no significant changes in the attached Ti nanoparticles during an operation period of 3 weeks. CONCLUSION It was demonstrated that the Ti‐dipping method is applicable to MFCs as an electrode modification strategy by Ti nanoparticle formation, leading to a similar level of voltage generation (but through a much simpler process) as compared with conventional evaporation methods. © 2019 Society of Chemical Industry

Chandru Thomare, Abhishek Nagappagol, Triveni Magadum et al.

Research Square • 2025

Abstract This paper describes a comprehensive mathematical model for simulating the performance of microbial fuel cells (MFCs) with MATLAB. The model involves bioelectrochemical, mass transport, and microbial growth kinetics to predict MFC behaviour at different operating conditions. A two-chamber MFC arrangement was simulated with specific interest in substrate utilization, biofilm growth kinetics, and electrochemical reaction at the anode. The model was able to accurately simulate polarization curves, power density yield, and rate of substrate degradation with precision less than 7% from experiments documented on lab-scale MFCs. Sensitivity analyses indicated biofilm conductivity and substrate concentration as factors that play a major role in affecting power production, with optimal performance for certain hydraulic retention times. The simulation framework provides a useful tool for the optimization of MFC design, minimizing the need for large laboratory experimentation. The ability of the model to forecast long-term performance and stability makes it especially suitable for upscaling MFC technology for real-world applications in wastewater treatment and bioenergy generation.

Jing Guo, Jianping Cheng, Jiaquan Wang et al.

Water Science and Technology • 2020

Abstract This study evaluated the effects of temporary external voltage on the performance of two-chambered microbial fuel cells (MFC) that use nitrate wastewater as a substrate. Results indicate that the external voltage affected the performance of the MFC during their operation, and this effect remained even after the voltage was removed. The degradation efficiency of the chemical oxygen demand increased in the MFC under external voltages of 0.5, 0.8, and 1.1 V, and the optimal applied voltage was 1.1 V. Compared with the control group without external voltages, the MFC under a voltage of 1.1 V achieved higher current densities and efficiency of nitrate removal during their operation. The MFC with an applied voltage of 1.1 V also achieved the highest maximum power density of 2,035.08 mW/m3. The applied voltages of 0.5 and 0.8 V exerted a positive effect on the performance of the MFC. High-throughput sequencing was used to explore the anode and cathode biofilms. Results showed that the influence was highly associated with microbial community in bio-anode. The predominant functional family changed from Methanotrichaceae during start-up to Flavobacteriaceae in a steady phase.

N. Rajalakshmi, V. Vijay, S. Pandian et al.

2nd International Conference on Fuel Cell Science, Engineering and Technology • 2003

In the production of Proton Exchange Membrane Fuel Cell (PEMFC) stacks with multiple cell units, graphite has been widely used as a bipolar material. Graphite has excellent electrical conductivity, high electrochemical stability, and good machining characteristics, enabling fine and complex fuel/oxidant flow fields to be used. In spite of the above advantages, search for alternate materials is counting owing mainly to the present requirement of reduced cell volume and weight per power yield (kW) in many applications. Cost reduction for this component and volume production are other driving forces for the continuous thrust in this subject. Flexible (exfoliated) graphite is an alternate material that could meet many of the above requirements. We have made use of flexible graphite to fabricate a PEM fuel cell stack. The flow fields were introduced by stamping. An optimization study has been carried out for the width and depth of the flow field designs in terms of applied pressure to accommodate the resilience of the flexible graphite sheet. The performance of the 500 watts stack fabricated using this material compares well with that fabricated using the conventional graphite plates. However there are some technical issues still to be sorted out which will be discussed.

A. Tremouli, T. Kamperidis, P. Pandis et al.

Global NEST International Conference on Environmental Science & Technology • 2022

Microbial fuel cells (MFC) are bioelectrochemical systems that convert the chemical energy contained in waste to electricity, using bacteria as catalysts. In order to boost the power output of MFCs, various approaches are feasible. This study examines the effect of using MnO2, activated carbon and fly ash as catalysts on the performance of three identical single-chamber MFCs. Ceramic (mullite) tubes run through the chamber providing structural support to the catalyst. Graphite granules were used as the anode electrode for all units. The cells operated in batch mode using glucose (1.5 g COD/L) as substrate. High COD removal efficiencies (>75%) were achieved for all units. The best performance in terms of power output was achieved when using MnO2 catalyst (Pmax=2.32 W/m3).

Yasser A. Attia, Mohamed Samer, Mahmoud S. M. Mohamed et al.

Biomass Conversion and Biorefinery • 2022

Abstract Microbial fuel cells (MFCs) are devices where bacteria generate electrical energy by oxidizing organic matter in wastewater. The implementation of MFCs on a commercial scale is limited due to electrode resistances, which are one of the key factors limiting electricity generation. This study presents a method to maximize the electrical power production from MFCs by coating the electrodes using nanomaterials which leads to prototyping novel electrodes having higher electrical conductivity than common electrodes. The voltage reached 1.234 V directly after operating the MFCs, with nanocoated electrodes, and showed voltage stability till the end of the 140 h interval with a peak value of 1.367 V with a maximum areal power density of 116 mW m −2 and a maximum volumetric power density of 15.6 mW m −3 . However, the voltage of the control (without coating) was steadily increased to 0.616 V after 22 h with a maximum areal power density of 23.6 mW m −2 and a maximum volumetric power density of 3.2 mW m −3 then showed voltage stability till the end of the 140 h interval. It was found that the coulombic efficiency of the MFCs where its electrodes are coated with graphitic carbon nitride nanosheets was higher than graphene, carbon nanotubes, and the control in a descending order, respectively. By this method, it is possible to improve the electrical conductivity of the MFCs which results in increasing the generated electrical power by 4.9 times the conventional method.

Chun Yu Ling, Ming Han, Yunzhong Chen et al.

Journal of Fuel Cell Science and Technology • 2015

Abstract An optimal or near to optimal design and operation of a direct liquid fuel cell (DLFC) stack requires an understanding of the relevant physical phenomena across length scales in the stack. In particular, perturbations between cells can arise due to external manifold design as well as variations in material and design parameters between cells. In this work, we seek to derive closed-form analytical expressions that capture the global stack performance, as well as individual cell behavior such as cell potential, current density, and methanol distribution. This approach allows for the simulation of large stacks with near to negligible computational overhead. Finally, the solutions are demonstrated for a stack subjected to perturbations in the anode inlet velocity of each cell.

Shaoan Cheng, Weifeng Liu, Dan Sun et al.

Surface and Interface Analysis • 2016

The physicochemical properties of anode material are important for the electron transfer of anode bacteria and electricity generation of microbial fuel cells (MFCs). In this work, carbon cloth anode was pretreated with isopropanol, hydrogen peroxide (H 2 O 2 ) and sodium hypochlorite (NaOCl) in order to reduce the anode functional groups. The influence of functional groups on the electrochemical properties of carbon cloth anode and power generation of MFCs was investigated. The anode pretreatments removed the surface sizing layer of carbon cloth and substantially reduced the contents of C‐O and pyridinic/pyrrolic N groups on the anode. Electrochemical impedance spectroscopy and cyclic voltammetry analyses of the biofilm‐matured anodes revealed an enhanced electrochemical electron transfer property because of the anode pretreatments. As compared with the untreated control (612 ± 6 mW m −2 ), the maximum power density of an acetate‐fed single‐chamber MFC was increased by 26% (773 ± 5 mW m −2 ) with the isopropanol treated anode. Additional treatment with H 2 O 2 and NaOCl further increased the maximum power output to 844 ± 5 mW m −2 and 831 ± 4 mWm −2 . A nearly inverse liner relationship was observed between the contents of C‐O and pyridinic/pyrrolic N groups on anodes and the anodic exchange current density and the power output of MFCs, indicating an adverse effect of these functional groups on the electricity production of anodes. Results from this study will further our understanding on the microbial interaction with carbon‐based electrodes and provide an important guidance for the modification of anode materials for MFCs in future studies. Copyright © 2016 John Wiley & Sons, Ltd.

Lea Ouaknin Hirsch, Bharath Gandu, Abhishiktha Chiliveru et al.

Microorganisms • 2024

The bacterial anode in microbial fuel cells was modified by increasing the biofilm’s adhesion to the anode material using kaolin and graphite nanoparticles. The MFCs were inoculated with G. sulfurreducens, kaolin (12.5 g·L−1), and three different concentrations of graphite (0.25, 1.25, and 2.5 g·L−1). The modified anode with the graphite nanoparticles (1.25 g·L−1) showed the highest electroactivity and biofilm viability. A potential of 0.59, 0.45, and 0.23 V and a power density of 0.54 W·m−2, 0.3 W·m−2, and 0.2 W·m−2 were obtained by the MFCs based on kaolin–graphite nanoparticles, kaolin, and bare anodes, respectively. The kaolin–graphite anode exhibited the highest Coulombic efficiency (21%) compared with the kaolin (17%) and the bare (14%) anodes. Scanning electron microscopy and confocal laser scanning microscopy revealed a large amount of biofilm on the kaolin–graphite anode. We assume that the graphite nanoparticles increased the charge transfer between the bacteria that are in the biofilm and are far from the anode material. The addition of kaolin and graphite nanoparticles increased the attachment of several bacteria. Thus, for MFCs that are fed with wastewater, the modified anode should be prepared with a pure culture of G. sulfurreducens before adding wastewater that includes non-exoelectrogenic bacteria.

Tao Jin, Lei Zhou, Jianmei Luo et al.

Journal of Chemical Technology & Biotechnology • 2013

Abstract Background The anode material is considered a key factor influencing the energy conversion in microbial fuel cells ( MFCs ) because it links microbiology and electrochemistry. To further improve power generation, carbon mesh anodes modified by hydrazine hydrate chemical reduction were applied in air‐cathode MFCs . Results The power densities of MFCs using hydrazine‐treated anodes were all higher than the untreated control, among which a 30% hydrazine hydrate‐modified anode ( CM ‐30%) showed the best performance. The maximum power density reached 865 mW m −2 , which was 31% higher than the unmodified control ( CM ‐0%, 662 mW m −2 ). The Coulombic efficiency ( CE ) increased from 10.7% to 13.3% (improved by 24.3%). Furthermore, the acclimation time was reduced from 142 h to 95 h, shortened by 32% compared with the control. Such improvement in MFCs performance was correlated with the increased surface area revealed by scanning electron microscope ( SEM ) and the change of surface functional groups revealed by X‐ray photoelectron spectroscopy ( XPS ) analysis. This enhancement in MFCs performance was also proved feasible when using real swine wastewater as substrate . Conclusions The results indicated that hydrazine hydrate chemical reduction was an effective method for anode modification to improve the performance of MFCs . © 2013 Society of Chemical Industry

Chandani Polgolla, Jun Xia, Xi Zhuo Jiang

Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy • 2025

This work presents a three-dimensional numerical study on the impact of geometrical parameters of the porous transport layers of a proton exchange membrane fuel cell (PEMFC) on its overall performance using ANSYS Fluent, with the overall current density as the key performance indicator under typical operating voltages of an automotive PEMFC, meanwhile maintaining proper two-phase water transport throughout the transport layers on both electrodes. The coupled charge, mass, momentum, species and energy conservation equations with source terms due to electrochemical reactions and phase change among different phases of water were solved to obtain a steady-state solution, typically using over 1.5 million meshes for the fuel cell, with each transport layer “resolved” in the height direction measuring the layer thickness. The modelling approach is validated against the measured polarisation profile of a PEMFC. Optimising the thicknesses h ’s of the porous transport layers is the focus of this study. Without changing other characteristics of these porous media, it would naturally be the first step to optimise the configuration of a fuel cell, which requires the least monetary and knowledge investment but potentially leads to substantial performance improvement, especially if the volume of the fuel cell can be reduced, which is important for automotive applications. Although past numerical studies that usually focused on one transport layer have offered valuable insights into optimising a fuel cell’s configutration to achieve optimal performance, it will be necessary to investigate a fuel cell as an integrated entity when performance optimisation is the objective, since realistic boundary conditions for all porous transport layers are determined in real time rather than assumed. Via an iterative approach, the present study has attempted to optimise the thicknesses of all porous transport layers of a single fuel cell. Optimal performance of the PEMFC was achieved with a reduction of its volume by 5.1%.

Daniela Velazquez, Juan-Carlos Sigala, Luz María Martínez et al.

Microbial Cell Factories • 2022

Abstract Background Fed-batch mode is the standard culture technology for industrial bioprocesses. Nevertheless, most of the early-stage cell and process development is carried out in batch cultures, which can bias the initial selection of expression systems. Cell engineering can provide an alternative to fed-batch cultures for high-throughput screening and host selection. We have previously reported a library of Escherichia coli strains with single and multiple deletions of genes involved in glucose transport. Compared to their wild type (W3110), the mutant strains displayed lower glucose uptake, growth and aerobic acetate production rates. Therefore, when cultured in batch mode, such mutants may perform similar to W3110 cultured in fed-batch mode. To test that hypothesis, we evaluated the constitutive expression of the green fluorescence protein (GFP) in batch cultures in microbioreactors using a semi defined medium supplemented with 10 or 20 g/L glucose + 0.4 g yeast extract/g glucose. Results The mutant strains cultured in batch mode displayed a fast-growth phase (growth rate between 0.40 and 0.60 h −1 ) followed by a slow-growth phase (growth rate between 0.05 and 0.15 h −1 ), similar to typical fed-batch cultures. The phase of slow growth is most probably caused by depletion of key amino acids. Three mutants attained the highest GFP fluorescence. Particularly, a mutant named WHIC (Δ ptsHIcrr , Δ mglABC ), reached a GFP fluorescence up to 14-fold greater than that of W3110. Strain WHIC was cultured in 2 L bioreactors in batch mode with 100 g/L glucose + 50 g/L yeast extract. These cultures were compared with exponentially fed-batch cultures of W3110 maintaining the same slow-growth of WHIC (0.05 h −1 ) and using the same total amount of glucose and yeast extract than in WHIC cultures. The WHIC strain produced approx. 450 mg/L GFP, while W3110 only 220 mg/L. Conclusion The combination of cell engineering and high throughput screening allowed the selection of a particular mutant that mimics fed-batch behavior in batch cultures. Moreover, the amount of GFP produced by the strain WHIC was substantially higher than that of W3110 under both, batch and fed-batch schemes. Therefore, our results represent a valuable technology for accelerated bioprocess development.

Irma Lucía Vera-Estrada, Andrés Dector, Víctor Manuel Ovando-Medina et al.

Research Square • 2023

Abstract Urine has recently been considered a source of novel biomarkers for early disease detection; developing more autonomous medical devices would be possible if the urine is also used as fuel in microfluidic fuel cells. This work presents a paper-based microfluidic fuel cell that operates, for the first time, with diabetic urine. Diabetic urine has a different composition than normal urine, and some molecules could affect urea oxidation and decrease fuel cell power generation. This work shows a selective catalyst of ZnO and nickel-based particles used as anode in a paper-based microfluidic fuel cell. Catalysts with different concentrations of Ni +2 were evaluated. The best results were obtained with 3% nickel, using diabetic urine; the maximum voltage achieved was 0.89 V, with a maximum current density of 1.18 mA cm -2 and a maximum power density of 1.26 mW cm -2 .

Hongpeng Zhang, Marco Chen, Ruoqian Lu

Highlights in Science, Engineering and Technology • 2023

The development of Microbial Fuel Cell (MFC) technology has progressed greatly in the past few decades to the point where it can now be considered viable in certain industries. MFCs are cells that utilize microorganisms as catalysts to transform wastes into electrical energy, this new type of bioenergy can generate energy as well as decompose the wastes produced from industries and daily life. This article provides an overview of MFC’s properties, factors influencing the performance of MFCs, recent applications and prospects of MFCs, and the advantages and weaknesses of MFCs. Biofouling and waste debris from reaction inside the cell as well as not suitable pH value will cause significant degrade in performance of MFCs, at the same time, magnetic field and environmental temperature can help improve MFCs’ performance if utilized properly. Compared to other bioenergy technologies, MFCs do not need intensive heat and the cost of reaction materials is extremely low, nevertheless, the low energy output, relatively short life span, and high cost of materials building MFC itself are still barriers challenging MFCs to be widely adopted. Recently, MFCs are utilized in various areas, they are available for both electricity and hydrogen production, and they can deal with waste treatment or bioremediation at the same time. This paper aims at finding solutions to the existing problems of MFCs and exploring a wider range of areas that MFCs can be utilized.

Chin Tsan Wang

Applied Mechanics and Materials • 2014

Sediment microbial fuel cells (SMFCs) produce electricity through the bacterial oxidation of organic matter contained in the sediment, but the power density is limited and needs to be improved. In this study, a new design of a fined-type cathode with carbon cloth embedded partly, as opposed to completely, in SMFCs were utilized. As a result, the design allowing the cathode to contact air will have a positive effect on the power performance and decrease the resistance of the inner system. The power density in the cases where the cathode was about half soaked was about two folds the case where it was soaked completely. Furthermore, SMFCs would also be seen as a driving force in hastening the COD removal because it was about 1.92-folds the COD removal of the cases where SMFCs where not present. These findings can be applied to sewage treatment and improving the power performance in SMFCs.

Zhizhao Xiao, Max Rümenapf, Max Hackbarth et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2025

Abstract A 10 L Rotating Disc Bioelectrochemical Reactor (RDBER) was operated as a microbial electrolysis cell (MEC) under different rotational speeds and counter electrode configurations. Increasing the anode’s speed from 0.25 to 1 rpm raised the anodic current density from 55 ± 14 to 100 ± 7 A m -3 while increasing hydrogen production rates from 0.05 ± 0.01 to 0.18 ± 0.01 . Higher speeds provided no further benefit. Moving the counter electrodes to the upper reactor half reduced observed hydrogen shuttling. The modified RDBER reached current densities of 1.98 ± 0.11 A m -2 and 0.99 ± 0.03 hydrogen production. Optical coherence tomography confirmed biofilm morphology changes but no significant increase in biovolume or substratum coverage. Hydrogen recovery remained below 50%. While the RDBER achieved high volumetric current densities and volumetric hydrogen production rates compared to other MEC pilots, improvements in anodic current density and cathodic hydrogen recovery are required for practical application. Graphical Abstract Highlights 10 L RDBER was operated as MEC in batch experiments at different rotational speeds hydrogen shuttling was reduced through cathode displacement Current densities of 198 ± 11 A m -3 and H 2 -production rates of 0.99 ± 0.03 L L R -1 d -1 Anodic biofilm parameters were not significantly altered by cathode modification

Elena Carcadea, D. B. Ingham, L. Ma et al.

Volume 2: Controls, Diagnostics and Instrumentation; Cycle Innovations; Electric Power • 2007

Proton exchange membrane (PEM) fuel cells have been identified as a viable emerging technology for future power generation systems in terms of both stationary and mobile applications since it offers a significant economical and environmental potential in future power production. This paper presents the development of a PEM fuel cell system using a full three-dimensional computational fluid dynamics model for the system optimization. The fuel cell investigated is a seven serpentine channel cell of 100cm2 active area. The model includes a complete set of mathematical equations for the fluid flow, multi-component species transport, electrochemistry, and the transport of protons and electrical currents throughout the PEM fuel cell. The results obtained from the parametric analyses of the cell performance at different current loads have been presented. The model results provide us detailed information on the fluid dynamics and electrochemical processes that occur in the fuel cell. This generates a clear picture on the fuel/oxidant distribution, consumption, and the current density distribution in the fuel cell. This assists us in identifying the critical parameters that influence the cell performance and sheds light onto the physical mechanisms leading to the improvement of the fuel cell system performance.

Bibiana Cercado, Ana Laura Vega-Guerrero, Francisco Rodríguez-Valadez et al.

Journal of the Mexican Chemical Society • 2017

The effect of real dairy wastewater (DWW) additions on the current density generated by a bioanode was evaluated in a half cell configuration under potentiostatic control, thus simulating the anodic chamber of a Microbial Fuel Cell. Low substrate additions increased current density up to 1655 ± 136 mA m-2, forming a two-current peak pattern. Then the system was tested with a casein-lactose synthetic media. A high protein concentration reduced the current density; individual compounds led to the highest current (330.5 mA m-2 with casein; 1276 mA m-2 with lactose). Moreover, the protein reduced the current start up time.

D. Sa´nchez, R. Chacartegui, A. Mun˜oz et al.

Volume 2: Controls, Diagnostics and Instrumentation; Cycle Innovations; Electric Power • 2007

The integration of high temperature fuel cells — molten carbonate and solid oxide — and gas turbine engines for efficient power generation is not new. Different strategies for integrating both systems have been proposed in the past ten years and there are some field tests being run presently. However, the commercial availability of such power systems seems to be continuously delayed, probably due to cost and reliability problems. The materials used in high temperature fuel cells are expensive and their cost is not decreasing at the expected pace. In fact, it looks as if they had reached stabilization. Therefore, there seems to be agreement that operating at a lower temperature might be the only way to achieve more competitive costs to enter the market, as metallic materials could then be used. From the point of view of conventional hybrid systems, decreasing the operating temperature of the cell would affect the efficiency of the bottoming cycle dramatically, as long as turbine inlet temperature is a critical parameter for the performance of a Brayton cycle. This is the reason why hybrid systems perform better with solid oxide fuel cells operating at 1000 °C than with molten carbonate cells at 650 °C typically. This work presents a hybrid system comprising a high temperature fuel cell, either SOFC or MCFC, and a bottoming Brayton cycle working with supercritical carbon dioxide. A parametric analysis is done where all the parameters affecting the performance of the hybrid system are studied, with emphasis in the bottoming cycle. For the Brayton cycle: pressure ratio, expansion and compression efficiencies, recuperator effectiveness, pressure losses, turbine inlet temperature... For the fuel cell: fuel utilization, current density, operating temperature, etc. From this analysis, optimum operating point and integration scheme are established and, after this, a comparison with conventional hybrid systems using similar fuel cells is done. Results show that, although the fuel cell is not pressurized in the CO2 based system, its performance is similar to the best conventional cycle. Furthermore, if lower operating temperatures are considered for the fuel cell, the new system performs better than any of the conventional.

Magdalena Dudek, Mikołaj Zarzycki, Andrzej Raźniak et al.

Energies • 2023

The novel constructions of hybrid energy sources using polymer electrolyte fuel cells (PEMFCs), and supercapacitors are developed. Studies on the energy demand and peak electrical power of unmanned ground vehicles (UGVs) weighing up to 100 kg were conducted under various conditions. It was found that the average electrical power required does not exceed ~2 kW under all conditions studied. However, under the dynamic electrical load of the electric drive of mobile robots, the short peak power exceeded 2 kW, and the highest current load was in the range of 80–90 A. The electrical performance of a family of PEMFC stacks built in open-cathode mode was determined. A hydrogen-usage control strategy for power generation, cleaning processes, and humidification was analysed. The integration of a PEMFC stack with a bank of supercapacitors makes it possible to mitigate the voltage dips. These occur periodically at short time intervals as a result of short-circuit operation. In the second construction, the recovery of electrical energy dissipated by a short-circuit unit (SCU) was also demonstrated in the integrated PEMFC stack and supercapacitor bank system. The concept of an energy-efficient, mobile, and environmentally friendly hydrogen charging unit has been proposed. It comprises (i) a hydrogen anion exchange membrane electrolyser, (ii) a photovoltaic installation, (iii) a battery storage, (iv) a hydrogen buffer storage in a buffer tank, (v) a hydrogen compression unit, and (vi) composite tanks.

Daniel Gonzalo Arboleda Avilés, Oscar Fernando Núñez Barrionuevo, Omar Fernando Sánchez Olmedo et al.

Revista Colombiana de Química • 2019

Every year the demand for energy worldwide is increasing. There are some alternatives to reduce these problems, such as clean energy or renewable energy. A particular alternative is the microbial fuel cells. These cells are biochemical reactors that convert chemical energy into electricity. The present research evaluated the dairy serum to produce bioelectricity from micro fuel cells (MFC) that were constructed with low-cost materials and with isolated bacteria in anaerobic sediments, located in Ecuadorian national territory, producing maximum voltages of 0.830 V in the circuit and a maximum power density of 30mW / m2. This low voltage was worked with 50 mL MFCs and with an output voltage of 300 mV. Under these conditions, a FLYBACK lift circuit isolated by the transformer was designed. This new circuit could increase the voltage from 30 mV to enough voltage to light a 2.5 V LED. Therefore, the energy produced by the MFC can be directly used to light a LED and to charge capacitors. This study shows that these MFCs, together with the designed circuit, could be used potentially to generate clean energy.

Shixuan Jin, Yiyu Feng, Jichao Jia et al.

ENERGY & ENVIRONMENTAL MATERIALS • 2022

Optimizing the structure of electrode materials is one of the most effective strategies for designing high‐power microbial fuel cells (MFCs). However, electrode materials currently suffer from a series of shortcomings that limit the output of MFCs, such as high intrinsic resistance, poor electrolyte wettability, and low microbial load capacity. Here, a three‐dimensional (3D) nitrogen‐doped multiwalled carbon nanotube/graphene (N‐MWCNT/GA) composite aerogel is synthesized as the anode for MFCs. Comparing nitrogen‐doped GA, MWCNT/GA, and N‐MWCNT/GA, the macroporous hydrophilic N‐MWCNT/GA electrode with an average pore size of 4.24 µm enables high‐density loading of the microbes and facilitates extracellular electron transfer with low intrinsic resistance. Consequently, the hydrophilic surface of N‐MWCNT can generate high charge mobility, enabling a high‐power output performance of the MFC. In consequence, the MFC system based on N‐MWCNT/GA anode exhibits a peak power density and output voltage of 2977.8 mW m −2 and 0.654 V, which are 1.83 times and 16.3% higher than those obtained with MWCNT/GA, respectively. These results demonstrate that 3D N‐MWCNT/GA anodes can be developed for high‐power MFCs in different environments by optimizing their chemical and microstructures.

Robert W. Atkinson, Yannick Garsany, Keith Bethune et al.

ECS Meeting Abstracts • 2019

Proton exchange membrane fuel cell (PEMFC) power production is highly influenced by the properties of the gas diffusion media (GDM). The GDM typically comprise a mesoporous carbon layer (MPL) on top of a porous carbon-fiber gas diffusion layer (GDL) which are both wetted with polytetrafluoroethylene ( PTFE) to modify their water retention. In a PEMFC, the GDM are compressed to either side of the catalyst coated membrane. The GDM are active in the fuel cell transport processes including electron and heat conduction, water removal, and distributing reactant gases to the catalyst layers, which affects the electrochemistry in the catalyst layers. These transport phenomena rely on both the properties of the GDM solid phase and its voids, making optimization of GDM material properties challenging. The majority of reports in the PEMFC literature addressing GDM focus solely on the cathode, since water is produced at this electrode and its ineffective removal can block active sites and occlude O 2 diffusion. Most research reports use symmetrical anode and cathode GDM. To date, there has been less discussion on the role of the anode GDM or how anode and cathode GDM properties can be selected in concert to increase fuel cell power output, despite that a significant amount of water in a fuel cell is rejected to the anode. We consider that anode and cathode GDM properties, such as air permeability, must be chosen in unison to improve cell water management. In our previous work, we used X-ray computed tomography to observe that dry-laid, non-woven, Freudenberg GDM maintain large void volume while permitting high compressive stress, ultimately resulting in lower contact and ohmic resistances and better mass transport compared to another distinct class of GDM (wet-laid, SGL). 1 In this work, we make a range of PEMFCs using a suite of Freudenberg GDM to study the influence of anode and cathode GDM air permeability and how these properties may be paired to improve cell hydration and increase fuel cell power production in a broad range of operating conditions. Fuel cells are characterized with cyclic voltammetry, electrochemical impedance spectroscopy (EIS), gravimetric analysis, and limiting current measurements to quantify the sources of mass transport resistance. Gradients of GDM material properties from anode to cathode improve cell hydration and facilitate water removal to reduce mass transport resistances and enable higher power operation. 1. “The Role of Compressive Stress on Gas Diffusion Media Morphology and Fuel Cell Performance,” R. W. Atkinson III, Y. Garsany, B. D. Gould, K. E. Swider-Lyons, I. V Zenyuk, ACS Applied Energy Materials, 2017, 1 (1), 191–201.

Ziad T. Alismaeel, Mohanad J. M‐Ridha, Mohammed G. Shamikh et al.

ChemistrySelect • 2024

Abstract The crisis of obtaining drinking water and electrical energy from clean sources has been the primary focus of researchers seeking ecologically acceptable and cost‐effective alternatives. The microbial desalination cell (MDC) has shown to be one of the most cost‐effective and promising ways for creating electricity, cleaning sewage water, and naturally desalinating water. In this work, the AEM (Anion Exchange Membrane) was used in the anodic chamber, and potassium ferricyanide in the cathodic chamber as catholyte solution. Meanwhile, SEM (Scanning electron microscopy) analyses was used to define the resulting surface morphologies. This study gave an optimization model by Central Composite Design model, where all the variables affecting the microbial desalination cell (the initial concentration of COD (Chemical Oxygen Demand), the initial concentration of TDS (Total dissolved solids) and the operating time of the cell) were entered to obtain an equation for each response (electrical energy productivity, COD removal efficiency and water desalination efficiency) in addition to study the ANOVA (Analysis of variance) for each response and study the interactions of the variables with each other that affect the response. The variables were determined for the initial concentration of (COD) from (300‐1200 mg/L) and the initial concentration of (TDS) from (15–35 g/L) and the duration of the operating time was from (4–24 h) the maximum productivity was obtained. The power was 2.2 mW, and the maximum water desalination gave 42 %, and the optimum COD removal was 35 %. In addition to diagnosing the active sludge employed and defining the kind of bacteria controlling it, this research looked at the breakdown of the yield of ion exchange membranes, which had a negative impact on the desalination process and the productivity of electrical energy.

Zhiming Zhang, Sai Wu, Huimin Miao et al.

Sustainability • 2022

High-power proton exchange membrane (PEM) fuel cell vehicles are important for the realization of carbon neutrality in transportation. However, it is difficult to maintain enough fuel supply and quick water removal capacity at a high current density where reactant gas transportation and water concentration are directly affected by flow channel configurations. This study aims to investigate the tapered slope effects of a flow channel on fuel cell performance using a 3-D CFD model. The positive, negative, zero and hybrid tapered slopes are proposed to illustrate the fuel cell voltage, reactant gas and water vapor concentration in the flow channels. Among them, the flow channel with a positive tapered slope performs better, especially at a high current density. Then, the positive tapered slope effects are discussed, including different tapered slopes, inlet depths and widths of flow channels. The results show that the larger the tapered slope, the smaller the depth and width, and the better the fuel cell performs; the corresponding current densities are increased by a maximum of 6.53%, 12.72% and 61.13%. The outcomes stated above provide a key direction for flow channel design that can particularly achieve higher fuel cell power density at high current densities.

Annukka Santasalo-Aarnio, Pekka Peljo, Eero Aspberg et al.

ECS Transactions • 2010

The performance of an alkaline direct alcohol fuel cell (DAFC) supplied with a FAA-2 membrane as an electrolyte and utilizing methanol, ethanol and iso-propanol solutions as a fuel was studied. In addition, the permeability of these fuels through the membrane is investigated at different concentration to facilitate the interpretation of the fuel cell results. The permeability decreased with the increasing size of the alcohol molecule and it was some ten times lower through FAA-2 compared to Nafion® 115 for all the studied fuels. In the alkaline DAFC, the highest power density was obtained with 1 mol dm-3 iso-propanol (0.75 mW cm-2). However, the cell showed good performance with more concentrated fuels, even with 15 mol dm-3 methanol solution. Solution resistances of these MEA materials at different fuels and concentrations were obtained with electrochemical impedance spectroscopy.

C. H. Tsai, C. S. Hwang, C. L. Chang et al.

Fuel Cells • 2013

Abstract The metal‐supported intermediate temperature solid oxide fuel cells with a porous nickel substrate, a nano‐structured LDC (Ce 0.55 La 0.45 O 2–δ )–Ni composite anode, an LDC diffusion barrier layer, an LSGM (La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3–δ ) electrolyte, an LSCF (La 0.58 Sr 0.4 Co 0.2 Fe 0.8 O 3–δ )–LSGM composite cathode interlayer and an LSCF cathode current collector are fabricated by atmospheric plasma spraying. Four different plasma spraying powers of 26, 28, 30, and 34 kW are used to fabricate the LSCF–LSGM composite cathode interlayers. Each cell with a prepared LSCF–LSGM composite cathode interlayer has been post‐heat treated at 960 °C for 2 h in air with an applied pressure of 450 g cm –2 . The current‐voltage‐power and AC impedance measurements indicate that the LSCF–LSGM composite cathode interlayer formed at 28 kW plasma spraying power has the best power performance and the smallest polarization resistance at temperatures from 600 to 800 °C. The microstructure of the LSCF–LSGM composite cathode interlayer shows to be less dense and composed of smaller dense regions as the plasma spraying power decreases to 28 kW. The durability test of the cell with an optimized LSCF–LSGM composite cathode interlayer gives a degradation rate of 1.1% kh –1 at the 0.3 A cm –2 constant current density and 750 °C test temperature.