Monday, 6 November 2017

Fuel Cell as Energy Alternative in Electric Vehicles

There have been ongoing research in providing alternative energy sources. This is especially needed in the field of vehicle manufacturing where there are so many challenges associated with the internal combustion engine.

Today we would  discuss Fuel Cells under the following topics:
  • What are fuel cells?
  • Types of Fuel Cells
  • How do they work?
  • How does it compare to conventional batteries?
  • How efficient are they in electric vehicles?

What are Fuel Cells?
A fuel cell is a cell that converts chemical energy(fuel) into electrical energy by means of electrochemical reaction. The converted electrical energy could then be used for other processes such as lighting, driving some motor, powering some electronic devices in the vehicle etc.
The chemical used in fuel cell is normally hydrogen and this is store in  some chamber from where it is discharged into a chamber where it combines with oxygen to produce electrical energy.

Types of Fuel Cells
I would just outline the types without given details of how each type works because all of them operated on the same basic principle.
  • PEMFC(Proton Exchange Membrane Fuel Cell
  • Alcaline Fuel Cell(AFC)
  • HTFC (High Temperature Fuel Cell)
  • SAFC (Solid Acid/Oxide Fuel Cell)
  • MCFC(Molten Carbonate Fuel Cell)
There are a few other variants but these are the most commonly used.

How Does Fuel Cell Work?
The components of a fuel cell includes:
the Anode
the Electrolyte
the Cathode
At the anode, the fuel is oxidized(mixed with oxygen) producing ions and electrons. The ions passes through the electrolyte to the cathode. At the cathode, the positive ions combines with electrons, an the end result is water or carbon dioxide. The process is more complex than this, but I have tried to keep it very simple. The process is illustrated in Figure 1.

Figure 1: Basic Structure of a Fuel Cell

How Does Fuel Cell Compare With Conventional Batteries?
1. One of the key difference between a fuel cell and a battery is that a battery stores energy, but a fuel cell does not. In a fuel cell, the energy produced by the electrochemical is simultaneously used by connected electronics and so it is not stored.
2. Unlike batteries that works with electrolytes, a fuel cell works with fuel which actually can run out. So in case of fuel cell, there must be continuous supply of fuel for the cell to continue producing energy.
3. A battery normally had a life span, that is the duration the battery is designed to work, but a fuel cell does not.

Use of Fuel Cell in Electric Vehicles
As an alternative to the internal combustion engine, much research is being made on the used of fuel cells to drive vehicles especially because of its benefits. Such benefits includes 'zero pollution'. Actually, it may not be zero, but compared to the pollution from internal combustion engines, the pollution from use of fuel cell could be considered zero. It is considered one of the most environmental-friendly energy sources for automobiles.
In 2015, Toyota successfully launched a vehicle that used fuel cell, Toyota Mirai. You can read up about this on your own. However, the success of fuel cell vehicles have been largely slow, partly due to the cost of hydrogen as well as the technology.
We have that in the coming decades, fuel cell would be find use not just in electric vehicles but also in appliances and electrical equipment.

I wish I could write more, but like I use to say, I try as much as I can to keep it simple, brief and clear. If this have been informative for you, leave a comment below.