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.

Samuel Simon Araya, Søren Juhl Andreasen, Søren Knudsen Kær

ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology • 2014

As fuel cells are increasingly commercialized for various applications, harmonized and industry-relevant test procedures are necessary to benchmark tests and to ensure comparability of stack performance results from different parties. This paper reports the results of parametric sensitivity tests performed based on test procedures proposed by a European project, Stack-Test. The sensitivity of a Nafion-based low temperature PEMFC stack’s performance to parametric changes was the main objective of the tests. Four crucial parameters for fuel cell operation were chosen; relative humidity, temperature, pressure, and stoichiometry at varying current density. Furthermore, procedures for polarization curve recording were also tested both in ascending and descending current directions.

Hwa-Seob Song, Jong-Chul Hong, Gyu-Jin Jang et al.

Journal of Fuel Cell Science and Technology • 2013

In this study, Hyosung demonstrates how a dual-cell structured polymer electrolyte membrane fuel cells (PEMFC) can guarantee the development of a stack with enlarged active area and cost innovation without a change in electrochemical performance and operation conditions. The insertion of insulation part within the bipolar plate and divided membrane electrode assemblies allowed the two individual cells in single layer. This enables the development of highly cost effective stack for PEMFC of a 1 kW class for residential power generators. The decrease in the number of layers can be represented as a cost reduction. We developed a stack of 24 layers with 48 cells, 48 V at open circuit voltage (OCV) and achieved a performance rating of 0.75 V per cell at 250 mA/cm2.

Linde Ren, Jinrong Lu, Hua Liu

New Journal of Chemistry • 2021

Herein, the output power density produced by Fe–Cu–NC- x as the cathode catalyst of a MFC was higher than that of the AC control.

Solène Moulin, Bertrand Légeret, Stéphanie Blangy et al.

Scientific Reports • 2019

Abstract Use of microbes to produce liquid transportation fuels is not yet economically viable. A key point to reduce production costs is the design a cell factory that combines the continuous production of drop-in fuel molecules with the ability to recover products from the cell culture at low cost. Medium-chain hydrocarbons seem ideal targets because they can be produced from abundant fatty acids and, due to their volatility, can be easily collected in gas phase. However, pathways used to produce hydrocarbons from fatty acids require two steps, low efficient enzymes and/or complex electron donors. Recently, a new hydrocarbon-forming route involving a single enzyme called fatty acid photodecarboxylase (FAP) was discovered in microalgae. Here, we show that in illuminated E. coli cultures coexpression of FAP and a medium-chain fatty acid thioesterase results in continuous release of volatile hydrocarbons. Maximum hydrocarbon productivity was reached under low/medium light while higher irradiance resulted in decreased amounts of FAP. It was also found that the production rate of hydrocarbons was constant for at least 5 days and that 30% of total hydrocarbons could be collected in the gas phase of the culture. This work thus demonstrates that the photochemistry of the FAP can be harnessed to design a simple cell factory that continuously produces hydrocarbons easy to recover and in pure form.

Epiphane Zingbe, Damgou Mani Kongnine, Bienvenu M. Agbomahena et al.

Electrochem • 2025

In a plant microbial fuel cell (P-MFC), the plant provides the fuel in the form of exudates secreted by the roots, which are oxidised by electroactive bacteria. The immature plant is hampered by low energy yields. Several factors may explain this situation, including the low open-circuit voltage of the plant cell. This is a function of the development of the biofilm formed by the electroactive bacteria on the surface of the anode, in relation to the availability of the exudates produced by the roots. In order to exploit the fertilising role of biochars, a plant cell was developed from C. citratus and grown in a medium to which 5% by mass of coconut shell biochar had been added. Its effect was studied as well as the distance between the electrodes. The potential of Cymbopogon citratus was also evaluated. Three samples without biochar, with inter-electrode distances of 2, 5 and 7 cm, respectively, identified as SCS2, SCS5 and SCS7, and three with the addition of 5 % biochar, with the same inter-electrode distance values, identified as S2, S5 and S7, were prepared. Open-circuit voltage (OCV) measurements were taken at 6 a.m., 1 p.m. and 8 p.m. The results showed that all the samples had high open-circuit voltage values at 1 p.m. Samples containing 5% biochar had open-circuit voltages increased by 16 %, 8.94% and 5.78%, respectively, for inter-electrode distances of 2, 5 and 7 cm compared with those containing no biochar. Furthermore, the highest open-circuit voltage values were obtained for all samples with C. citratus at an inter-electrode distance of 5 cm. The maximum power output of the PMFC with C. citratus in this study was 75.8 mW/m2, which is much higher than the power output of PMFCs in recent studies.

Yilkal Dessie, Sisay Tadesse, Rajalakshmanan Eswaramoorthy

Journal of Nanomaterials • 2021

In this study, biosynthesized α-MnO2/NiO NPs and chemically oxidative polyaniline (PANI) were synthesized to form ternary composite anode material for MFC. The synthesized materials were characterized with different materials (UV-Vis, FTIR, XRD, TGA-DTA-DSC, SEM-EDX-Gwyddion, CV, and EIS) to deeply examine their optical, structural, morphological, thermal, roughness, and electrocatalytic properties. The degree of surface roughness for α-MnO2/NiO/PANI was 23.65 ± 5.652 nm . This value was higher than the pure α-MnO2, pure PANI, and even α-MnO2/PANI nanocomposite due to surface modification. The total charge storing performance for bare PGE, α-MnO2/PGE, PANI/PGE, α-MnO2/PANI/PGE, and α-MnO2/NiO/PANI/PGE were 5.291, 17.267, 20.659, 23.258, and 24.456 mC. From this, the charge storing performance formed by α-MnO2/NiO/PANI-modified PGE was highest, indicating that this electrode is best in cycle stability and increases its life cycle during energy conversion time in MFC. This is also supported by its effective surface area, having a value of 0.00984 cm2. From this, it is evidenced that the ternary composite catalyst-modified anode facilitates the fast electrocatalytic activity as observed from its high peak current and lower peak-to-peak potential separation ( Δ E p = 0.216 V ) than other electrodes. Such surface modification helps to store more electrical charge by increasing electrical conductivity during its charge/discharge processing time. In addition, the lower charge transfer resistance property with a value of 788.9 Ω and the fast heterogeneous electron transfer rate of ~2.92 s-1 enable to facilitate glucose oxidation, and this enhances to produce high power output and increase wastewater treatment efficiency. As a result, the bioelectrical activity of α-MnO2/NiO/PANI composite-modified PGE was very effective in producing a maximum power density of 506.96 mW m-2 with COD of 81.92%. The above observations justified that α-MnO2/NiO/PANI/PGE serves as an effective anode material in double-chambered MFC application.

B. R. Ringeisen, S. E. Lizewski, L. A. Fitzgerald et al.

Electroanalysis • 2010

Abstract Electrochemically active bacteria (EAB) are prominently found in aquatic environmental sediment samples and wastewater streams, which are known to contain several different types of microorganisms. Even though microbial consortia are found to enhance both Coulombic efficiency and total power output in microbial fuel cells (MFCs), it is currently unknown how many different EAB contribute to current generation in these systems. It is also difficult to track the relative population of different species during MFC operation. We used biological laser printing (BioLP) to isolate different bacterium from complex environmental samples and MFC anolytes. BioLP can be used to print droplets containing a single cell directly from liquid culture, thereby enabling EAB to be sorted from unmodified environmental or MFC samples. Isolated species were identified through 16S rDNA analysis of pure cultures derived from the printed samples. These experiments demonstrate how cell printing can be used as a single‐step method to separate and identify microorganisms from complex environmental samples and operating MFCs.

Daisie D. Boettner, Gino Paganelli, Yann G. Guezennec et al.

Dynamic Systems and Control • 2001

Abstract This paper describes use of a Proton Exchange Membrane (PEM) fuel cell system model for automotive applications in a fuel cell system/battery hybrid configuration. The fuel cell system model has been integrated into a vehicle performance simulator that determines fuel economy and allows consideration of control strategies. The simulator is used to explore relevant regions of the fuel cell-powered hybrid electric vehicle design space by conducting simulations using two simple supervisory-control strategies: thermostatic control and proportional control. During the simulations power provided by the battery and fuel cell system and operational limits on battery state of charge and fuel cell system current density are varied while maintaining minimum component sizing to meet vehicle performance criteria. Analysis of results from these simulations provides component power sizing and limits of operation suitable for development of a more advanced supervisory vehicle control strategy for a fuel cell vehicle.

Akil Ahmad, Mohammed B. Alshammari, Mohamad Nasir Mohamad Ibrahim

Processes • 2023

Microbial fuel cells (MFCs) are thought to be ecologically friendly, despite electron transport and generation challenges. In order to address this, the efficiency of MFCs was investigated using two different anode electrodes made from biomass: graphene oxide (GO) and graphene oxide-metal oxide (GO-MO) (GO-ZnO). After 18 days of operation, the maximum power density for GO was 0.69 mW/m2, whereas the maximum power density for GO-ZnO was 1.05 mW/m2. Furthermore, the ability of MFCs to transform the soluble metal ions (Cd2+, Cr3+, Pb2+, and Ni2+) into an insoluble state was investigated, which is a secondary use of MFCs with significant benefits. In the soluble state of metal ion transformation into an insoluble state, the rate of GO-ZnO was higher (92.71%) than that of GO (81.20%). The outcomes of material, analytical, and biological tests undertaken to validate the efficiency of anodes are presented. It has been shown that using innovative materials as electrodes in MFCs is a potential method for improving electron transport. Furthermore, as an organic substrate, food waste seems to be a viable alternative to more traditional options. In light of these discoveries, we investigate various unanswered issues and possibilities for MFCs. Organic substrate evaluation trials were also included in the present results to demonstrate that organic waste may be a reliable source of MFC performance. This article also has a thorough discussion of food waste oxidation, as well as challenges and future recommendations.

Nurhazirah Mohd Azmi, Nadira Anandita, Husnul Azan Tajarudin et al.

Journal of Physics: Conference Series • 2021

Abstract Fossil fuels have supported the industrialization and economic growth of countries during the past centuries and it is clear that they cannot indefinitely sustain in a longer time. In this study, membrane-less microbial fuel cell (ML-MFC) with mediators-less and air cathode had potential solution to generate electricity power and at the same time could reduce the abundant of food waste (1.64 kg/daily, around 8 tonnes/year) which dumped in the landfill and it’s cost effective device. The ML-MFC operated electrochemically incorporate electrogenic bacteria (EB) acted as a biocatalyst in order to produce electricity. The performance and optimization performance of food waste was evaluated using one-factor-at-a-time (OFAT) method and it was focused to pH for power generation. To determine the generated electricity the polarization curve was used to evaluate the performance of ML-MFC. The chemical oxygen demand (COD) of food waste was studied. The optimization of pH condition in ML-MFC was ranging from 7 to 9. Results showed that pH 8 was the optimum pH for EB strain, Bacillus Subtilis , with the high voltage (807 mV), EB biomass (15.46 mg/L), and power density (373.3 mW/m 2 ) generated. Clearly the pH environment condition affected the efficiency of ML-MFC performance. The increase in EB biomass also increased the voltage in the ML-MFC, proving that EB biomass and voltage were associated with growth.

Elham Shafiee Roudbari, Mohammad Taghi Hamidi Beheshti, Seyed Mehdi Rakhtala

IET Power Electronics • 2019

Nowadays, the demand for electrical energy is increasing, and conventional power systems will face major problems in the future if they cannot generate extra demand for electrical energy. One of the best solutions for solving extra demand for electrical energy is the use of renewable resources to produce energy. The main aim of this study is designing and controlling the microgrid voltage and frequency. This study proposed the voltage and frequency control of an islanded microgrid based on fuzzy logic controller. The system considered for this study consists of Proton‐Exchange Membrane Fuel Cell (PEMFC) that connected to parallel inverters to convert DC voltage to AC voltage. The control structure is based on adaptive droop control and fuzzy voltage control loop. Also, the proposed structure controls active and reactive powers and decreases power losses of the microgrid. Simulation results are presented to show the effectiveness and robustness of the proposed control structure over the conventional proportional–integral controller. It is shown that the proposed controller has good transient response under the output voltage PEMFC variation and load changes as disturbance.

S. Jouttijärvi, Xueli Yao, M. I. Asghar et al.

Research Square • 2020

Abstract A mixed ionic and semiconducting composite in a single-layer configuration has been shown to work as a fuel cell at a lower temperature (500-600 oC) than a traditional solid-oxide fuel cell. The performance of a single-layer fuel cell (SLFC) is often limited by high resistive losses. Here, an eutectic mixture of alkali-carbonates was added to SLFC to improve the ionic conductivity. The dual-phase composite ionic conductor consisted of a ternary carbonate (sodium lithium potassium carbonate, NLKC) mixed with gadolinium-doped cerium oxide (GDC). Lithium nickel zinc oxide (LNZ) was used as the semiconducting material. The LNZ-GDC-NLKC SLFC reached a high power density, 582 mW/cm2 (conductivity 0.22 S/cm) at 600 °C, which is more than 30 times better than without the carbonate. The best results were obtained with the ternary carbonate which decreased the ohmic losses of the cell by more than 95%, whereas the SLFC with a binary carbonate (sodium lithium carbonate, NLC) showed a lower conductivity and performance (243 mW/cm2, 0.17 S/cm at 600°C). It is concluded that adding carbonates to LNZ-GDC will improve the ionic conductivity and positively contribute to the cell performance. These results suggest a potential path for further development of SLFCs, but also imply the need for efforts on up-scaling and stability to produce practical applications with SLFC.

Siddharth Rajupet, Clayton J. Radke, Adam Z. Weber

ECS Meeting Abstracts • 2024

Electrochemical reactions in proton-exchange-membrane (PEM) fuel cells occur within catalyst layers (CL). The catalyst layer consists of a porous network of metal-activated catalyst particles coated with an ion-conducting polymer binder (ionomer) that enables proton transport. Nafion, a perfluorinated sulfonic-acid polymer, is the common binder used and consists of a hydrophobic backbone with negatively charged sulfonic-acid side chains. Prior studies have shown the Nafion distribution in catalyst layers is nonuniform on both the nano 1 and micrometer-scale. 2 This inhomogeneity is thought to impede catalyst-layer performance by limiting proton transport in Nafion-deficient regions and limiting oxygen transport in Nafion-enriched regions. The Nafion distribution in the catalyst layer is governed by the ink from which it is deposited. The catalyst ink is a colloidal slurry consisting of catalyst-activated particles and Nafion typically dispersed in a water-alcohol solvent mixture. Within this ink, some Nafion adsorbs to the surface of catalyst particles, while the remainder is dispersed in solution. Prior studies hypothesize that adsorption in the ink facilitates a more uniform Nafion distribution in the final catalyst layer, thereby improving transport in the catalyst layer. 3,4 Here, we characterize Nafion adsorption in catalyst inks by sedimenting catalyst particles with adsorbed Nafion from inks. The adsorbed Nafion content of the sediment is measured using thermogravimetric analysis. Nafion adsorption to catalyst particles is irreversible and is limited by electrostatic repulsion of the negatively charged Nafion sidechains. We demonstrate that one can control the extent of adsorption by adding mineral acid to the ink to increase the ionic strength and decrease electrostatic repulsion. Through adding acid, the extent of Nafion adsorption to catalyst particles increases by more than a factor of 2 as shown in Figure 1 below. Next, the effect of Nafion adsorption in the ink is correlated to final catalyst-layer performance and properties via cell diagnostics including sheet resistance, polarization performance, and limiting-current measurements. Overall, the talk will elucidate the governing interactions that control Nafion adsorption and how this adsorption affects performance. Acknowledgements This work was funded under the Million Mile Fuel Cell Truck Consortium. References [1] Girod, R., Lazaridis, T., Gasteiger, H. A., & Tileli, V. (2023). Three-dimensional nanoimaging of fuel cell catalyst layers. Nature Catalysis , 6 (5), 383–391. https://doi.org/10.1038/s41929-023-00947-y [2] Orfanidi, A., Rheinländer, P. J., Schulte, N., & Gasteiger, H. A. (2018). Ink Solvent Dependence of the Ionomer Distribution in the Catalyst Layer of a PEMFC. Journal of The Electrochemical Society , 165 (14), F1254–F1263. https://doi.org/10.1149/2.1251814jes [3] Ott, S., Orfanidi, A., Schmies, H., Anke, B., Nong, H. N., Hübner, J., Gernert, U., Gliech, M., Lerch, M., & Strasser, P. (2020). Ionomer distribution control in porous carbon-supported catalyst layers for high-power and low Pt-loaded proton exchange membrane fuel cells. Nature Materials , 19 (1), 77–85. https://doi.org/10.1038/s41563-019-0487-0 [4] Islam, M. N., Mansoor Basha, A. B., Kollath, V. O., Soleymani, A. P., Jankovic, J., & Karan, K. (2022). Designing fuel cell catalyst support for superior catalytic activity and low mass-transport resistance. Nature Communications , 13 (1), 1–11. https://doi.org/10.1038/s41467-022-33892-8 Figure 1

Nur Izzati Iberahim, Nabilah Aminah Lutpi, Li‐Ngee Ho et al.

Environmental Quality Management • 2024

Abstract The purpose of this article is to assess the feasibility analysis of microbial fuel cells (MFCs), particularly in the configuration of dual chamber salt bridge microbial fuel cell (DCSB‐MFC), as a promising approach for simultaneous bioelectricity generation and wastewater remediation. The application of a salt bridge presents an economically viable alternative to the use of a proton exchange membrane, which is known for its high cost, in the construction of MFCs. This arrangement has been demonstrated to offer significant benefits in terms of enhancing the performance of new elements and evaluating operational parameters. However, it also encounters issues related to the total internal resistance (R int ) of the MFCs as well as power density (P). In addition, it has been found that traditional packing materials such activated carbon and gravel demonstrate poor permeability, internal resistance, and slow biofilm growth. Furthermore, there is a necessity to search for electrodes that possess high resistance to corrosion and are cost‐effective to achieve optimal bioelectricity generation. Therefore, this article aims to emphasize the research areas that require attention. By addressing these areas, the actual implementation of this configuration can be brought closer to practical implementation.

Nasser A. M. Barakat, Rasha H. Ali, Hak Yong Kim et al.

Nanomaterials • 2022

Carbon nanofiber-decorated graphite rods are introduced as effective and low-cost anodes for industrial wastewater-driven microbial fuel cells. Carbon nanofiber deposition on the surface of the graphite rods could be performed by the electrospinning of polyacrylonitrile/N,N-Dimethylformamide solution using the rod as nanofiber collector, which was calcined under inert atmosphere. The experimental results indicated that at 10 min electrospinning time, the proposed graphite anode demonstrates very good performance compared to the commercial anodes. Typically, the generated power density from sugarcane industry wastewater-driven air cathode microbial fuel cells were 13 ± 0.3, 23 ± 0.7, 43 ± 1.3, and 185 ± 7.4 mW/m2 using carbon paper, carbon felt, carbon cloth, and graphite rod coated by 10-min electrospinning time carbon nanofibers anodes, respectively. The distinct performance of the proposed anode came from creating 3D carbon nanofiber layer filled with the biocatalyst. Moreover, to annihilate the internal cell resistance, a membrane-less cell was assembled by utilizing a poly(vinylidene fluoride) electrospun nanofiber layer-coated cathode. This novel strategy inspired a highly hydrophobic layer on the cathode surface, preventing water leakage to avoid utilizing the membrane. However, in both anode and cathode modifications, the electrospinning time should be optimized. The best results were obtained at 5 and 10 min for the cathode and anode, respectively.

, Sahrani Saharuddin, Amalyah Febryanti et al.

Jurnal Sumberdaya Alam dan Lingkungan • 2024

Plant-Microbial Fuel Cell (P-MFC) is a green technology because it uses a biocathode in the cathode compartment and also uses microorganisms to break down the chemical energy of organic matter into electrical energy. In this research, molasses and Saccharomyces cereviceae were used as substrates and Ceratophyllum demersum as a biocathode in the cathode compartment. The purpose of this study was to determine the potential variation in plant weight of C. demersum as a biocathode in the P-MFC system. The results of this study indicated that the maximum current at the biocathode was at a weight of 70 g, namely 0.180 mA with a power density value of 13.664 mW.m-2 and the maximum potential difference at the biocathode was at a weight of 40 g, which as 0.310 mV with a power density value of 30.787 mW.m-2. Therefore, coontail water plant has the potential as biocathode.

Yi Zuo, Defeng Xing, John M. Regan et al.

Applied and Environmental Microbiology • 2008

ABSTRACT Exoelectrogenic bacteria have potential for many different biotechnology applications due to their ability to transfer electrons outside the cell to insoluble electron acceptors, such as metal oxides or the anodes of microbial fuel cells (MFCs). Very few exoelectrogens have been directly isolated from MFCs, and all of these organisms have been obtained by techniques that potentially restrict the diversity of exoelectrogenic bacteria. A special U-tube-shaped MFC was therefore developed to enrich exoelectrogenic bacteria with isolation based on dilution-to-extinction methods. Using this device, we obtained a pure culture identified as Ochrobactrum anthropi YZ-1 based on 16S rRNA gene sequencing and physiological and biochemical characterization. Strain YZ-1 was unable to respire using hydrous Fe(III) oxide but produced 89 mW/m 2 using acetate as the electron donor in the U-tube MFC. Strain YZ-1 produced current using a wide range of substrates, including acetate, lactate, propionate, butyrate, glucose, sucrose, cellobiose, glycerol, and ethanol. Like another exoelectrogenic bacterium ( Pseudomonas aeruginosa ), O. anthropi is an opportunistic pathogen, suggesting that electrogenesis should be explored as a characteristic that confers advantages to these types of pathogenic bacteria. Further applications of this new U-tube MFC system should provide a method for obtaining additional exoelectrogenic microorganisms that do not necessarily require metal oxides for cell respiration.

Obaid ur Rehman, Amber Fishan Zafar

Journal of Electrochemical Science and Engineering • 2017

<p class="PaperAbstract">The performance of proton exchange membrane (PEM) fuel cell majorly relies on properties of gas diffusion layer (GDL) which supports heat and mass transfer across the membrane electrode assembly. A novel approach is adopted in this work to analyze the activity of GDL during fuel cell operation on a large-scale model. The model with mesh size of 1.3 million computational cells for 50 cm<sup>2</sup> active area was simulated by parallel computing technique via computer cluster. Grid independence study showed less than 5% deviation in criterion parameter as mesh size was increased to 1.8 million cells. Good approximation was achieved as model was validated with the experimental data for Pt loading of 1 mg/cm<sup>2</sup>. The results showed that GDL with higher thermal conductivity prevented PEM from drying and led to improved protonic conduction. GDL with higher porosity enhanced the reaction but resulted in low output voltage which demonstrated the effect of contact resistance. In addition, the compressive force reduced the porosity under the rib regions which resulted in lower gas diffusion and heat and water accumulation.</p>

Shuiyun Shen, Chao Wang, Qinglei Zhang et al.

ECS Meeting Abstracts • 2016

To further improve the cell performance of a proton exchange membrane fuel cell (PEMFC), thus meeting the high requirement for its automotive and stationary application, great efforts have been made on the optimization of the flow field pattern[1,2]. In this work, two novel flow field patterns are proposed and the influences on the cell performance are investigated. Both two novel flow field designs lead to superior cell performance than the conventional flow field patterns do, and this can be attributed to their superiority in removing water at high current densities while increasing the flow velocity near the outlet. The velocity magnitude in flow fields is examined and compared through the computational fluid dynamics modeling. Acknowledgements This work was supported in part by National Natural Science Foundation of China (Grant No. 21373135 and 21533005) and Science Foundation of Ministry of Education of China ( Grant No. 413064). References [1] Soler, J., E. Hontanon, and L. Daza, Electrode permeability and flow-field configuration: influence on the performance of a PEMFC. Journal of Power Sources, 2003. 118(1): p. 172-178. [2] Lee, B., K. Park, and H.-M. Kim, Numerical Optimization of Flow Field Pattern by Mass Transfer and Electrochemical Reaction Characteristics in Proton Exchange Membrane Fuel Cells. Int. J. Electrochem. Sci, 2013. 8: p. 219-234.

Pedro Oliveira, Francisco Brójo, Rafael Domingues

Volume 6: Energy • 2024

Abstract Water-in-diesel emulsions (WiDE) are an alternative fuel to be used in diesel engines capable of offering the benefits of higher engine efficiency and lesser pollutant emissions. This work aims to show how differences in WiDE fuel temperatures may impact its combustion properties and how they translate into different performances and emissions. An emulsion composed of diesel, 8% (m/m) of distilled water, and 3% (m/m) surfactant was performed in laboratory by mechanical homogenization and tested in a single-cylinder Hatz 1B40 Direct Injection (DI) diesel engine coupled to an eddy current dynamometer, an emission gas analyzer, and an opacimeter. The tests were performed for the fuel temperatures of 40°C and 50°C, and at 75% of the maximum considered engine load at four different speeds. The results show that higher emulsion temperatures lead to lower NO emissions, higher CO emissions, and decreased thermal efficiency.

S. Jouttijärvi, Xueli Yao, M. I. Asghar et al.

Research Square • 2019

Abstract A mixed ionic and semiconducting composite in a single-layer configuration has been shown to work as a fuel cell at a lower temperature (500-600 oC) than a traditional solid-oxide fuel cell. The performance of such single-layer fuel cell (SLFC) is often limited by high resistive losses. Here, an eutectic mixture of alkali-carbonates was added to SLFC to improve the ionic conductivity. The dual-phase composite ionic conductor consisted of a ternary carbonate (sodium lithium potassium carbonate, NLKC) mixed with gadolinium-doped cerium oxide (GDC). Lithium nickel zinc oxide (LNZ) was used as the semiconducting material. The LNZ-GDC-NLKC SLFC reached a high power density, 582 mW/cm2 (conductivity 0.22 S/cm) at 600 °C, which is more than 30 times better than without the carbonate. The best results were obtained with the ternary carbonate which decreased the ohmic losses of the cell by more than 95%, whereas a binary carbonate (sodium lithium carbonate, NLC) showed a lower conductivity and performance (243 mW/cm2, 0.17 S/cm at 600°C). It is concluded that adding carbonates to the LNZ-GDC will improve the ionic conductivity and positively contribute to the cell performance. These results will help to design better-performing SLFCs in the future and highlight the potential of SLFCs as a candidate for future electricity generation.

Hong Gun Kim, Lee Ku Kwac, Sung Soo Kang et al.

Materials Science Forum • 2007

An experimental study is carried out to investigate the performance and the practical application of polymer electrolyte membrane fuel cell(PEMFC) with the double-tied catalyst layers in a Membrane Electrolyte Assembly (MEA). Characteristics of PEMFC depend highly on the conditions such as gas pressure, temperature, thickness, supplied oxidant type (Oxygen/Air) as well as humidification. They are controlled under the same condition for the comparison of the simulation. Testing condition is fixed at 60sccm and 70°C in anode and cathode, respectively. The humidification about 15% the performance is improved no humidification rather. The current density is increased around 20% significantly when pure oxygen gas is provided as an oxidant. It is found that measured values of unit cell voltage and current are influenced strongly by the type and amount of oxidant, which give more enhanced values in case of oxygen compared to the ambient air as oxidant.

Xiaoyi Jiang, Xintong Gao, Ke Yang et al.

Environmental Engineering Research • 2024

Iron minerals can significantly impact the performance of soil microbial fuel cells (Soil-MFCs) through extracellular electron transfer (EET). Introducing defects into iron minerals has been shown to reinforce the microbial dissolution process. In this study, oxygen-rich vacancy defects were successfully incorporated into hematite (DHem), resulting in enhanced Soil-MFCs performance. Voltage measurement and Polarization curves demonstrated that the addition of DHem yielded the highest electricity output of 408.96 mV and the highest power density of 324.97 mW/m2. Liquid chromatography revealed that the system with DHem exhibited the most effective phenanthrene degradation at 61.42%, with a 40.70% increase in degradation near cathode areas. The introduction of defects led to increased dissolution of Fe(II) in hematite. The dissolved Fe(II) showed a significant positive correlation with both electricity generation and phenanthrene degradation, confirming that the introduction of defects strengthened the long-distance electron transfer capability by enhancing the dissolution of hematite. In addition, after adding iron minerals, the abundance of Petrimonas, Pseudomonas, Trichococcus, and Azoarcus was increased, which were all important function microorganisms in the system. We concluded that the introduction of defects in hematite can enhance the overall performance of Soil-MFCs by enhance electron transfer and microbial community structure.

Arpita Nandy, Mohita Sharma, Senthil Venkatesan et al.

Energies • 2019

This study aims to provide insight into the cost-effective catalyst on power generation in a microbial fuel cell (MFC) for treatment of municipal sludge. Power production from MFCs with carbon, Fe2O3, and Pt electrodes were compared. The MFC with no coating on carbon generated the least power density (6.72 mW·m−2) while the MFC with Fe2O3-coating on carbon anodes and carbon cathodes generated a 78% higher power output (30.18 mW·m−2). The third MFC with Fe2O3-coated carbon anodes and Pt on carbon as the cathode catalyst generated the highest power density (73.16 mW·m−2) at room temperature. Although the power generated with a conventional Pt catalyst was more than two-fold higher than Fe2O3, this study suggests that Fe2O3 can be investigated further as an efficient, low-cost, and alternative catalyst of Pt, which can be optimized for improving performance of MFCs. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) results demonstrated reduced resistance of MFCs and better charge transfer between biofilm and electrodes containing coated anodes compared to non-coated anodes. Scanning electron microscopy (SEM) was used to analyze biofilm morphology and microbial community analysis was performed using 16S rRNA gene sequencing, which revealed the presence of known anaerobic fermenters and methanogens that may play a key role in energy generation in the MFCs.

Ravi Shankar, Prasenjit Mondal, Shri Chand

Environmental Progress & Sustainable Energy • 2014

This work deals with the simultaneous generation of electricity and removal of organic load from synthetic wastewater containing eqimolar concentration of glucose and glutamic acid. The effect of initial COD (mg/L), anodic pH and metals (Zn 2+ , Cr 6+ , and Fe 3+ ) concentration on the generation of current density and voltage has been studied. Although, the amount of COD removed increases with increase in the initial COD value from 500 to 2500 mg/L, the maximum generation of current density (19 mA/m 2 ) and voltage (14.8 mV), after 7 days of operation, is achieved at the initial COD value of 1500 mg/L at anodic pH value of 7. Difference in the anodic and cathodic pH has also been observed maximum (∼1) at the initial COD value of 1500 mg/L. Addition of metals initially increases the voltage and power density generation, attains a maximum value at a certain metal concentration and decreases thereafter with increase in metal concentration. Optimum concentration of metals, that is, 8 mg/L Zn 2+ , 7 mg/L Cr 6+ , and 10 mg/L Fe 3+ in the solution produces maximum voltage of 142, 490, and 321 mV, after 7 days of operation, respectively. Corresponding maximum power densities are 6.9, 508, and 192 mW/m 2 , respectively. The present process seems to have maximum current density and voltage generation capacity in comparison to some recently reported literatures on membrane less MFCand is able to reduce COD value below permissible limit with the initial COD value ≤1250 mg/L. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 255–264, 2015

Alfiah Alif, Muhamad Jalil Baari, Amalyah Febryanti

International Journal of Science, Technology & Management • 2023

Sediment Microbial Fuel Cell (MFC) is a technology that can convert chemical energy into electrical energy through the process of nutrient degradation by microbes. Sediment taken from the bottom of shrimp ponds was added as a source of microbes, while fish and shrimp wastewater were used as a source of nutrients for microbes. This study aims to measure the performance of the SMFC system on fish effluent and shrimp effluent to produce bio-electricity while reducing the waste load. The research method was experimental laboratories. The treatment given was the different types of electrodes, namely zinc-copper and aluminum-copper. In addition, 0.2 M KMnO4 electrolyte solution was used. This study consisted of four stages: the manufacture of nutrients from fish and shrimp wastewater, the manufacture of a dual chamber MFC bioreactor, the measurement of electrical values, and the analysis of waste quality. Experiments were carried out for 30 days by measuring electricity every 24 hours. The average value of electricity generated in the nutrients of fish wastewater with Zn/Cu electrodes was 0.705 V and Al/Cu was 0.472 V. Meanwhile, the average value of electricity in shrimp wastewater nutrients with Zn/Cu electrodes was 0.630 V and Al/Cu was 0.625 V. The number of colonies after adding sediment in the shrimp wastewater sample were 8.9 x 106 CFU/mL, the fish wastewater sample was 9.5 x 106 CFU/mL. It indicates the presence of microorganisms that play a role in the SMFC system

Sundas Bahar Yaqoob, Showkat Ahmad Bhawani, Rokhsana Mohammed Ismail Abdulrahman

Journal of Chemistry • 2021

Microbial fuel cells (MFCs) are a sustainable approach for the remediation of metals and the simultaneous production of energy. This paper highlighted the usage of mango extract to produce electricity as an organic source for bacteria and reduce metal ions from wastewater. The observed results were 51 mV in 15 days with 500 Ω of external resistance. The whole operation was carried out at room temperature. The observed current and power density were 28.947 mA/m2 and 0.972 mW/m2, respectively. The internal resistance was 150 Ω, which is lower than external resistance. The remediation performance varied with the metal ions as follows: Pb (II) shows 75%, Cd (II) shows 74.11%, and Cr (III) shows 80.50%. Finally, the detailed working mechanism of the present study, MFC challenges, and future research directions are covered in this paper.

Shizhe Peng, Jia Li, Yihan Hu et al.

Small • 2024

Abstract A decent stretchability is of paramount significance to operate microbial fuel cell (MFC) under mechanically dynamic conditions. However, it remains a grand challenge to fabricate fully stretchable MFC without compromising its power output. Here, using Shewanella oneidensis MR‐1 ( S. oneidensis ) as the model electrogenic bacteria, the study demonstrates a fully stretchable MFC device that can operate with a stretchability of 75%. The design takes advantage of a stretchable and ion‐conductive polyurethane membrane, which encapsulates the biohybrids composed of S. oneidensis and reduced graphene oxide (rGO) on the polydimethylsiloxane (PDMS) current collector for synchronous stretching. It is discovered that the “stretchable” living biohybrids can sustain an adaptive bio‐current output under stretching/releasing stimulation. The design also employs a stretchable air cathode. The stabilized peak power density of the stretchable MFC follows an increasing trend with the applied strain, and reaches 5.0 ± 0.7, 5.9 ± 0.9, 6.2 ± 1.1, 6.6 ± 1.4 µW cm −2 at strains of 0%, 25%, 50%, and 75%, respectively (n = 3). At 75% strain, the stretchable MFC yields a maximum current output of 104 ± 27 µA cm −2 and an open‐circuit voltage of 283 ± 30 mV (n = 3). The results provide insights to design stretchable MFCs to power the next‐generation on‐skin devices, soft robotics, and sustainable electronics.

Norhazirah Azhar, Thye-Foo Choo, Nur Ubaidah Saidin et al.

Engineering Headway • 2025

In the fabrication of fuel cell electrodes, applying catalyst ink onto a substrate is crucial. The performance of the proton exchange membrane fuel cell (PEMFC) is subsequently impacted by how the catalyst is applied onto substrate as well as in terms of its resulting morphology. In this study, a direct catalyst ink spraying approach was done in order to investigate transfer efficiency and surface morphology for different concentrations of ink. The concentration of catalyst ink used in the spraying process are 0.5, 1.0, 1.5, 2.0 and 2.5 mg/ml with fixed loading of 1.0 mg/cm 2 . The transfer efficiency of the catalyst inks was calculated neglecting human error during spraying. The coating thickness and distribution of the resulting catalysts were analysed via Field Emission – Scanning Electron Microscope (FESEM).