What is a fuel cell?
A fuel cell is an electrochemical device that converts the chemical energy of a fuel, usually hydrogen, directly into electrical energy and heat, producing water as the product of the reaction.
Schematic representation of the operation of a single fuel cell with hydrogen
A cell in a fuel cell consists of two porous electrodes separated by an electrolyte. The fuel passes through the anode, and the oxidant through the cathode. At the anode the fuel reacts by decomposing into ions and electrons. The electrons circulate through the external electrical circuit, and the ions pass through the electrolyte towards the opposite electrode.
Individual cells are assembly into stacks.
The number of cells in the stack determines the total voltage, and the area of each cell determines the total current.
Main difference between batteries and fuel cells:
- Batteries store electrical energy
- Fuel cells convert chemical energy in electrical energy
Testing of a fuel cell stack.
Fuel cells are considered as a promising alternative to the current internal combustion engines due to its high efficiency and zero emmisions if hydrogen is used as fuel.
Fuel cells will play a significant role in future energy scenarios, mainly in stationary, mobile and portable power generation applications.