Piotr Bujlo

High-Performance and Durable Membrane Electrode Assemblies for High-Temperature Polymer Electrolyte Membrane Fuel Cells

Membrane electrode assemblies (MEAs) with gas diffusion electrodes (GDEs) fabricated by various catalyst layer (CL) deposit technologies were investigated for the application of high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC). The physical properties of the GDEs were characterized by scanning electron microscopy (SEM) and pore size distribution. The electrochemical properties were evaluated and analyzed by polarization curve, Tafel equation, electrochemistry impedance spectroscopy (EIS), and cyclic voltammetry (CV). The results showed that the electrodes prepared by ultrasonic spraying and automatic catalyst spraying under irradiation (ACSUI) methods have superior CL structure and high electrochemistry activity, resulting in high fuel cell performances. Durability tests revealed the feasibility of the electrodes for long-term HT-PEMFC operation.

Experimental Evaluation of Supercapacitor-Fuel Cell Hybrid Power Source for HY-IEL Scooter

This paper presents the results of development of a hybrid fuel cell supercapacitor power system for vehicular applications that was developed and investigated at the Energy Sources Research Section of the Wroclaw Division of Electrotechnical Institute (IEL/OW). The hybrid power source consists of a polymer exchange membrane fuel cell (PEMFC) stack and an energy-type supercapacitor that supports the system in time of peak power demands. The developed system was installed in the HY-IEL electric scooter. The vehicle was equipped with auxiliary components (e.g., air compressor, hydrogen tank, and electromagnetic valves) needed for proper operation of the fuel cell stack, as well as electronic control circuits and a data storage unit that enabled on-line recording of system and vehicle operation parameters. Attention is focused on the system energy flow monitoring. The experimental part includes field test results of a vehicle powered with the fuel cell-supercapacitor system. Values of currents and voltages recorded for the system, as well as the vehicle’s velocity and hydrogen consumption rate, are presented versus time of the experiment. Operation of the hybrid power system is discussed and analysed based on the results of measurements obtained.

Conductivity of La- and Pr- doped Bi4V2O11

Presented work concerns BIVOX based solid electrolytes doped with lanthanum and praseodymium. Investigations of melting point and composition of new materials were performed by use of DTA and X-ray measurements. For determination of conductivity the impedance spectroscopy (IS) method was applied. Measurements were performed in wide range of frequency 20 Hz – 1 MHz and temperature 150 – 750 oC. The electrical measurements allowed evaluation of possible application in SOFC.

Investigations of Membrane Electrolytes for PEM Fuel Cell Applications

The work concerns new polymeric materials for electrolytes synthesized at the Electrotechnical Institute. Poly(styrene-4-sulfonate)-grafted poly(vinylidene fluoride) (PVDF-g- PSSA) membranes proton-exchange membranes were synthesised by free radical graft polymerization of polystyrene into PVDF films (50 *m thick) followed by sulfonation. Physical and electrochemical properties of that membranes were investigated. The membranes were tested as electrolytes in a single cell configuration system. The influence of working condition, as gas humidity and cell temperature on fuel cell performance were measured. Obtained performances were lower in comparison with commonly used electrolyte materials. At this stage of development the synthesized materials are not suitable for fuel cell application. The results gave authors information for selection membrane with the best parameters and chemical process configuration.

A Fuel Cell Hybrid Vehicle Powertrain Emulator: Energy Management and Experimental Analysis

In this paper, a fuel cell hybrid vehicle powertrain emulator is proposed as a feasible test bench for validating energy management strategies. Firstly, the configuration and structure of the emulator is briefly presented, and a fuel cell and lithium-ion battery hybrid vehicle model based on the data obtained from a real fuel cell-battery hybrid light electric vehicle is used for testing the stability of the emulator. The comparative experiment demonstrates a power simulation error of 3.848%. Secondly, a fuzzy logic algorithm-based energy management strategy was implemented on the emulator with an objective of optimizing the energy distribution between the fuel cell stack and battery pack via the corresponding rules and membership functions. Finally, an experiment test embedded the energy management strategy on the emulator is carried out during the urban dynamometer driving schedule (UDDS) cycle. And the results indicate that the fuel cell stack works primarily in low-load and constant driving conditions. Meanwhile, the battery pack supplies the dynamic instantaneous power to meet the power requirements during high-load conditions. It is fully consistent with the proposed energy management strategy. That is, the proposed emulator is a reliable platform for further energy management research.

Advances in HT-PEMFC MEAs

PEM (polymer electrolyte membrane) technology has been used in low-temperature fuel cells and high-temperature fuel cells, as well as water electrolyzers, for many years. Such electrochemical devices are of great interest and importance in the establishment of the so-called Hydrogen Economy . Advancement in polybenzimidazole (PBI)-based high-temperature proton exchange membrane fuel cells (HT-PEMFCs), specifically for stationary applications, has been achieved through systematic optimization of its components. Membrane electrode assembly (MEA) is the heart of an HT-PEMFC, and the fabrication of MEA is a key step for “real” HT-PEMFC applications. A series of studies on developing high-performance MEAs for PBI or ABPBI-based high-temperature fuel cells (120–180°C) are presented in this chapter. Some critical points and perspectives on developing high-performance MEAs are also summarized.

HT-PEMFC Modeling and Design

Modeling and simulation studies of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) are important in order to better understand the operational behavior of the fuel cell and its performance and lifetime. These models play important roles in the understanding and prediction of HT-PEMFC performance and durability by analyzing various crucial parameters such as species concentrations, local current densities, temperature gradients, and pressure distributions within the fuel cell. These fuel cell modeling studies are often performed at the single cell level or stack level based on specific requirements and it may be either steady-state or dynamic using isothermal or nonisothermal models. The details of the modeling and simulation studies of HT-PEMFC at fuel cell level and stack level models including thermal management and electrochemical models are discussed in this chapter.

Catalysts for High-Temperature Polymer Electrolyte Membrane Fuel Cells

Increasing the temperature of polymer electrolyte membrane fuel cells (PEMFCs) implies advantages and disadvantages in terms of material cost, performance, and degradation. Platinum (Pt) is the best catalytic material for high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) electrodes, owing to the possibility it affords of minimizing CO poisoning with temperature enhancement. Nevertheless, it involves an increase in overall cost, mainly due to the larger platinum loadings used (when compared to Pt loadings for low-temperature polymer electrolyte membrane fuel cells). On the other hand, cathodic electrocatalysts still require that the kinetics of the sluggish oxygen reduction reaction be improved. Another disadvantage associated with the use of anodic and cathodic electrocatalysts is the corrosion of both carbon supports and catalytic nanoparticles, which is promoted by the increase in temperature. In this section, the most important factors affecting the performance of these materials are described and a brief description of the state of the art in the design and use of new materials in HT-PEMFCs is presented.

Stationary HT-PEMFC-Based Systems—Combined Heat and Power Generation

A combined heat and power (CHP) system for energy generation is the most suitable stationary application for fuel cells. High-temperature polymer electrolyte membrane fuel cell (HT-PEMFC)-based fuel cell CHP (FC-CHP) systems, owing to their high operating temperatures, have simpler layouts for auxiliary devices and can operate on reformate with relatively high CO content. The most suitable application of HT-PEMFC technology is in systems where utilization of heat is essential. This makes HT-PEMFC perfect for FC-CHP applications in which electrical energy and heat are produced in a cogenerated manner, enhancing the total efficiency of the overall system. Currently a few HT-PEMFC-based FC-CHP systems are being deployed worldwide and the results of preliminary validation are promising for the technology’s potential commercialization in the near future.

Hydrogen and Fuel Cell Technologies at the Hydrogen South Africa (HySA) Systems Competence Centre

*Email: bgpollet@hysasystems.org The Hydrogen South Africa (HySA) programme is based upon the benefi ciation of South Africa’s large platinum group metal (pgm) resources. The present article summarises some of the progress by HySA Systems, one of the three Competence Centres under the HySA Programme, since 2008. Work has been carried out on membrane electrode assembly and stack development for high-temperature proton exchange membrane fuel cells (HT-PEMFCs) for use in combined heat and power (CHP) supplied by natural gas and hydrogen fuelled vehicle (HFV) applications. The emphasis is on improved carbon monoxide tolerance and simplifi ed heat and humidity management, allowing simpler fuel cell systems to be designed. Metal hydrides modifi ed with palladium are being explored as poisoning-tolerant hydrogen storage materials for stationary and special mobile applications, and metal organic frameworks (MOFs) modifi ed with platinum as light-weight hydrogen storage with a high hydrogen storage capacity. Lastly research into hydrogen purifi cation using Pd membrane reactors is focused on membrane support synthesis, hollow fi bre seeding and development of the plating procedure.