Transport applications tend to demand rapid start-up and instant dynamic response from fuel cell systems, so a high-temperature fuel cell is unlikely to be competitive as the main engine in applications such as cars and buses. The prime candidate for these vehicle propulsion systems is the Polymer Electrolyte Fuel Cells, which exhibits both of the above characteristics while also having very high power density. This is important as it must also occupy a similar amount of space to an internal combustion engine. Of recent interest has been the development of auxiliary power units for vehicles, in which the fuel cell meets the onboard electric load of the vehicle. Both Polymer Electrolyte Fuel Cells and ITSOFCs are under development for this application. (more…)

Alkaline fuel cell, often known as the Bacon fuel cell following the British inventor’ name. It has become the most created fuel cell systems and is the cell which traveled Man to the Moon. NASA has utilized alkaline fuel cells since beginning of-1960s, in Apollo-series tasks and on the Space Shuttle. The alkaline fuel cell has a long history in the space program. It is still used in the space shuttle in an expensive guise, producing power for the onboard systems by combining the pure hydrogen and oxygen stored in the rocket-fuelling system. (more…)

Fuel cells are typically classified according to type of electrolyte. While many varieties of fuel cells have been demonstrated in the laboratory, five major types are seeing development for commercial applications:

* Polymer electrolyte membrane (PEM) cells use a plastic (polymer) membrane that becomes electrically conducting when hydrated (saturated with water); they operate near 1001C.
* Alkaline fuel cells use a caustic electrolyte such as potassium hydroxide (KOH); they also operate near 1001C. (more…)

Polymer Electrolyte Fuel Cells have high-power density, rapid startup, and low-temperature operation (around 80 to 120 C), and so are ideal for use in applications such as energy transport and battery replacement. The electrolyte used is a proton conducting polymer. This is typically a perfluorinated polymer, though other hydrocarbon-based membranes are under development in an attempt to reduce cost or to enable operation at temperatures approaching 200 C. The catalytically active layer sits adjacent to the membrane, supported on a PTFE treated carbon paper, which acts as current collector and gas diffusion layer. For operation on pure hydrogen, platinum is the most active catalyst, but alloys of platinum and ruthenium are used when higher levels of carbon monoxide are present (CO is a poison in all low temperature fuel cells). (more…)

A fuel cell is an electrochemical device that directly converts a fuel to electricity by means of reactions on the surfaces of electrodes and transport of ions through an electrolyte. A fuel cell can be thought of as a chemical battery whose reactants are fed from external sources rather than packaged as part of the battery. A key feature of a fuel cell is transformation of the chemical potential energy of a fuel directly into electricity, a high-value form of energy that can be put to many uses from electricity conversion. The fuel cell’s direct energy unit conversion process occurs without an intermediate step of heat generation, as involved in combustion engines. (more…)

The most commonly researched and most developed application of using hydrogen as a fuel source is in conjunction with a hydrogen fuel cell. Fuel cells operate by mixing hydrogen and oxygen to produce water and electricity. The electricity can then be used to provide power to homes, schools, and even businesses or to power cars and other vehicles. Some experts believe that internal combustion engines (ICEs) that are fueled by hydrogen are just as important. Hydrogen could be used as fuel for transportation by creating internal combustion engines for vehicles that run on hydrogen or hydrogen fuel mixtures. (more…)