Supercapacitors (other names: supercapacitors, double layer capacitors (EDLC)) are energy storage devices that are functionally equivalent to any other type of capacitor known. However, the difference is that supercapacitors can store thousands of times more energy than any electrolytic capacitor (Y type capacitors).
This may be at the expense of using special nanoporous carbon with a very high surface area of up to 2000 m2 / g. Since the device’s capacity is proportional to the surface area of the capacitor plate, it is possible to build a supercapacitor with a capacity of several thousand farads (F) in a small volume. This makes supercapacitors an excellent energy storage device for a variety of applications on the market.
Supercapacitors feature high specific power, fast load/unload time (in seconds) and long life: up to one million load/unload cycles. In addition, supercapacitors are very environmentally friendly and are safe to operate compared to lithium ion batteries, for example, without requiring much maintenance.
The sum of the above parameters is the market positioning of supercapacitors: they are best suited for applications that require increased power in the short term. Let’s take a look at some of the superior applications of supercapacitors.
In the automotive industry, supercapacitors are used in regenerative braking applications due to their fast charging capabilities. In particular, the Kinetic Energy Recovery System (KERS) can recover the kinetic energy generated by the moving vehicle during braking. The energy collected in this way can be accelerated later.
Starting and stopping the system to automatically stop and restart the internal combustion engine (ICE) to minimize downtime is another important area. Parking systems help reduce fuel consumption and emissions when vehicles spend a lot of time waiting for traffic jams. In view of the stricter regulations on carbon dioxide emissions in some countries, supercapacitors seem to be a very promising solution (Y type capacitors).
There is no doubt that supercapacitors can start the engine at low temperatures: cold start. The problem is that ordinary batteries do not perform well at low temperatures and fail. This is because the battery electrolyte becomes more viscous below zero and the chemical process slows down under these conditions. However, this problem does not affect the operation of the supercapacitor because it does not use chemical processes to store energy. The parallel connection of the supercapacitor to the lead acid battery reduces the size and necessary capacity of the starter battery for cold start.
Heavy and public transportation is another important part of supercapacitors. The heavy-duty hybrid market is already the most mature part of the supercapacitor market and continues to grow rapidly. In this case, the supercapacitor is used again to store and reuse the energy from the regenerative braking. In this area, supercapacitors can be used in both embedded and fixed systems. Cold start of diesel engines for trucks and trains and emergency power supplies for several subsystems are attractive opportunities in this area.