How A Hydrogen Fuel Cell Engine Works [Infographic]

About Chris Clark

Chris is a writer, a keen fencer and in his spare time a turbo-charged petrol head who enjoys track days, car shows and reading about cars he'll probably never own. He also drove a reasonably priced car around the Top Gear test track in a respectable 1:49.0

More posts by Chris Clark

Hydrogen fuel cell technology has come far in recent decades, from its early years launching rockets into space, to finally arriving on our roads as part of the energy revolution. While still a relatively young technology, hydrogen offers a real alternative to the polluting engines that have plagued the planet for the last century. Critics argue that hydrogen fuel cell engines are not as efficient as alternatives, and they are not 100% green due to the release of methane during hydrogen extraction. Nonetheless, we felt it was important to demonstrate how the hydrogen fuel cell works, and what is involved in making the wheels turn as we step ever so closer to a greener future.

Hydrogen Fuel Cell

How A Hydrogen Fuel Cell Engine Works – Transcript

The days of the petrol driven car are numbered. With an ever-increasing need to clean up our carbon footprint, so does the need grow for an alternative to the CO2 emitting engines that populate our roads. Luckily, alternative fuel sources are emerging, and the hydrogen fuel cell is becoming a big player on the market.

How the Fuel Cell Works

Fuel cell stacks: Fuel cells generate electricity thorough a chemical reaction between hydrogen and oxygen. Since one cell can only yield less than one volt, several hundred cells are connected in a series to increase the voltage. This combined body of cells is called a fuel cell stack.

How electricity is generated from hydrogen and oxygen in a fuel cell

1. Hydrogen is supplied to the anode side of the cell.

2. Hydrogen molecules activated by the anode catalyst release their electrons.

3. The released electrons travel from the anode to the cathode, creating an electrical current.

4. The hydrogen molecules that release electrons become hydrogen ions and move through the polymer electrolyte membrane to the cathode side.

5. The hydrogen ions bond with airborne oxygen and electrons on the cathode catalyst to form water.

FC boost converter: A Fuel Cell booster increases the voltage of the drive motor, reducing the number of required fuel cells while also reduce the weight and size of the whole system.

Drive battery: A rechargeable battery which stores energy during deceleration and adds this energy to the output of the fuel cells during acceleration.

Motor: Fuel Cell engines typically use an AC synchronous motor/generator.

Power Control Unit: This converts direct current (DC) into alternating current (AC) to power the motor, and a DC/DC converter that draws current from and then recharges the drive battery.

High-pressure hydrogen tanks: Each tank has three layers. The inner-most layer is a plastic tank holding the pressurized hydrogen at 70 Mpa. Then a carbon fibre reinforced plastic layer followed by a glass fiber reinforced plastic layer give the tank added strength and protection.

How does it work?

Hydrogen supplied to the cell have their electrons removed at the catalyst layer and become protons. Oxygen molecules taken from the air bond with the electrons and protons while transferring through the electrolyte membrane to produce water. The flow of electrons released from this reaction becomes the electricity that drives the motor.

How A Hydrogen Fuel Cell Engine Works