The Role of Ultracapacitors in Automotive Technologies

You still have to charge them up.

I do not know why I was expecting more from this post.

Conventional caoacitors are already used in the electonics industry. What do you mean by ultracapacitors? I guess you mean Lithium capacitors.

Well, let me tell you about the two main disadvantages of them. They have the voltage rating of a battery cell, only a few volts, and they are more expensive than conventional electrolytic capacitors.

Assuming that the automotive industry is not capable of making electric vehicles cheap enough, this will just not make sense. Unless you are paying a lot of money for something like a Tesla, of course.

I think you should learn more about ultracapacitors/supercapacitors, including the ability to string them in series to get any voltage you like. No different in that respect from a normal electrochemical battery. Their ability to sustain very rapid charge & discharge is complimentary to the characteristics of electrochemical batteries.

https://en.wikipedia.org/wiki/Supercapacitor

The Ragone chart provided by wikipedia is wrong about showing that supercaps have higher energy density than batteries. All examples show values up to 110 Wh/kg, while Li-ion batteries have from 100-580 Wh/kg.

In the end supercapacitors are something in between batteries and capacitors, but at a much higher price than a combination of both.

Supercaps have a higher POWER DENSITY than batteries, not ENERGY DENSITY. Which is why they are complimentary in electric vehicles.

These make a great deal of sense for handling transient peaks (both source and sink) such as starting and regen braking. They charge and discharge much faster and take that burden off the battery, extending its life. Really good idea.