Fuel cell

What are some of the challenges with using fuel cells (drawbacks)?

* Expensive: Fuel cells, particularly hydrogen fuel cells, can be expensive to manufacture and maintain. * Hydrogen storage: Hydrogen has a low energy density by volume, which requires large storage tanks or high-pressure compression. *Low efficiency compered to its counterparts. *Energy storage and conversion are separated *Possible catalyst poisoning * Hydrogen Infrastructure: Hydrogen, the most common fuel for fuel cells, lacks a well-developed infrastructure for production, distribution, and refueling.

What are some of the potential applications of fuel cells?

* Fuel Cell Vehicles (FCVs): Hydrogen fuel cells power electric vehicles. * Portable Generators: Fuel cells can be used in small, portable generators for remote or off-grid applications. * Uninterruptible Power Supplies (UPS): Fuel cells are used as backup power sources to ensure continuous operation of critical equipment and data centers. * Combined Heat and Power (CHP) Systems: Fuel cells can be used in homes, businesses, and industrial settings to simultaneously generate electricity and useful heat, improving overall energy efficiency.

What are the limiting factors during operation?

*Activation polarization: electrode kinetics. Activation energy. Losses due to sluggish kinetics. *Ohmic polarization:ionic flow in the electrolyte and electronic conductivity in the electrodes. Losses due to resistance. *Concentration polarization: Concentration polarization in a fuel cell occurs when the reactants (e.g., hydrogen and oxygen) near the electrodes are depleted faster than they can be replenished. This can reduce the fuel cell's efficiency and power output.

What are some of the ways we can improve fuel cell efficiency?

*Increase cell temperature:High-temperature fuel cells, like solid oxide fuel cells (SOFCs), typically have higher efficiencies due to reduced activation and ohmic losses.. *Use more effective catalysts. *Increase of the concentration of reactants.

How is hydrogen produced today?

*Natural gas(48%) *Oil(30%) *Coal(18%) *Electrolysis(4%)

How does a fuel cell work?

A fuel cell works by using a chemical reaction between a fuel (usually hydrogen) and oxygen to produce electricity. It separates electrons from protons in the fuel, creating an electric current, and the byproducts are water and heat.

What is a fuel cell?

An electrical cell that is supplied with a fuel and oxygen, and uses energy from the reaction between them to produce electrical energy efficiently.

What are the main differences between a fuel cell and a battery? Response time? Capacity?

Fuel cells and batteries are both electrochemical devices used for energy storage and conversion, but they have some key differences in how they operate: Fuel Cell: Requires a continuous supply of fuel (e.g., hydrogen) and an oxidizer (typically oxygen from the air) to function. It can run as long as fuel is supplied. Battery: Stores energy chemically within itself and doesn't require a constant external supply of fuel or reactants. Response Time: Fuel Cell: Provides a relatively constant output as long as there's a fuel supply, making them better suited for continuous power generation. Response time is relatively slower. Battery: Can discharge electricity quickly, making it suitable for applications where rapid energy release is needed. (Battery=Slow, Fuel cell=Slowest) Capacity: Fuel Cell: Can provide power for an extended period, limited by the availability of fuel. The capacity can be extended by refueling. Battery: Typically has a limited capacity determined by its internal chemistry, and it can discharge relatively quickly.

Name two fuel cells technology, benefits and drawbacks of each technique.

Proton Exchange Membrane Fuel Cells (PEMFCs) (the most common fuel cell): Benefits: *High Power Density: *Quick Start-Up: *Efficiency: typically with round-trip efficiencies exceeding 50%. *Low Operating Temperature Drawbacks: *Sensitivity to Contaminants *Cost: *Durability Solid Oxide Fuel Cells (SOFCs): Benefits: *High Efficiency: electrical efficiencies often exceeding 60%. *Fuel Flexibility: SOFCs can operate on a variety of fuels, including hydrogen, natural gas, and biogas. *Long Life: *High Operating Temperature. *Drawbacks: *High Operating Temperature *Size and Weight *Cost and Complexity *Slower Start-Up:

Name some of the losses that accrue in a fuel cell. What is the round-cycle efficiency of fuel cells?

Some diffrent losses: *Ohmic Losses: Ohmic losses occur due to the electrical resistance in the cell's components, such as the electrolyte and electrodes. Reducing these losses is crucial for improving the overall efficiency of fuel cells. *Activation polarization Losses: These losses are associated with the need to overcome the activation energy required for the electrochemical reactions to proceed. They can vary with operating conditions and fuel cell types. The round-trip efficiency of a fuel cell system can vary depending on the specific type of fuel cell. Generally, high-temperature fuel cells like solid oxide fuel cells (SOFCs) tend to have higher round-trip efficiencies, often exceeding 60%, while lower-temperature fuel cells like proton exchange membrane fuel cells (PEMFCs) may have round-trip efficiencies in the range of 40-60%.

What catalyst is currently most common in a fuel cell, why can this be a problem in the future?

The most common catalyst used in many fuel cells, especially proton exchange membrane fuel cells (PEMFCs), is platinum (Pt). Platinum is a rare, expansive and has a complex and expensive recycling process. These are just some of the factors that stops Fuel cells from becoming more mainstream.