U3AOS1 - Fuel Cells as a source of energy

Question 1

What is a Fuel Cell

Answer 1

Type of Galvanic Cell

That converts chemical energy to electrical energy - with fuel (reactants) being continuously pumped in

Question 2

Fuel Cell - Electrodes (Purpose)

Answer 2

Electrodes - Surface of Oxidation & Reduction

Question 3

Fuel Cell - Porous Electrodes

Answer 3

The electrodes can be porous - which means little holes in the them

This provides a greater surface area, and allows the reacting gases to access the electrolyte, and sometimes contain a catalyst

Can also be used to increase cell efficiency

Question 4

Fuel Cell - Anode vs Cathode (charge, reaction)

Answer 4

Anode - Negatively Charged - produces the electrical current
Fuels react at the anode

Cathode - positively charged - receives the electrical current

Question 5

Fuel Cell - The purpose of the Electrolyte/Membrane

Answer 5

• Complete the circuit by allowing the flow of charged particles through the cell
• Keep the products & reactants separated (preventing a spontaneous reaction)
• Transfers H+ (in Acidic Conditions) or OH- (in basic conditions)

Question 6

Fuel Cells vs Combustion - Energy Efficiencies

Answer 6

Fuel Cells: Roughly 60% energy efficient, only requires converting chemical energy into electrical energy

Combustion: Roughly 30% energy efficient, often requires multiple transformations (i.e. for coal-fired power station: chemical, to thermal, to mechanical to electrical)

Question 7

Fuel Cells - Safety

Answer 7

Fuel Cells: hydrogen fuel is explosive, and therefore, can be very dangerous to store

Question 8

Fuel Cells - Fuel Supply

Answer 8

can require the procurement of pure hydrogen

Question 9

Fuel Cells vs Combustion - Production of Greenhouse Gases

Answer 9

Fuel Cells: will vary based on the fuel used

Combustion: releases CO2 or CO, and often other gases depending on if the fuel is contaminated

Question 10

Fuel Cell vs Combustion - Sound

Answer 10

Fuel Cells are Quieter, Combustion is Louder

Question 11

Fuel Cells vs Galvanic Cells - Functions

Answer 11

Fuel Cells: Open System - that produces an ongoing supply of products (with an ongoing supply of reactants required)

Galvanic Cells: Closed System - contains just the reactants and products

Question 12

Fuel Cells vs Galvanic Cells - Design Features

Answer 12

Fuel Cells: Half Cells separated within the same vessel
w/ Porous Electrodes

Galvanic Cells: Half cell in separate vessel
w/ Inert Electrodes or Electrodes composed of products/reactants

Question 13

Fuel Cells vs Galvanic Cells - Examples of Applications

Answer 13

Fuel Cells: Usedd in submarines and some transport vehicles

Galvanic Cells: normally used as batteries for portable devices

Question 14

Fuel Cells vs Galvanic Cells - Energy Efficiencies

Answer 14

For the purpose of VCE - it’s similar - as they both only have one form of energy transformationn