Challenge

Week 5 Challenge

1. False

The battery is not a better choice to supply power in the given driving scenario.

Battery and Ultracapacitor complement each other by covering up each other's limitations.
The battery has high energy density but low power density.
Batteries have a chemical reaction happening in them through which they conduct electricity.
Ultracapacitors have a quick charge/discharge rate. They can absorb a lot of energy quickly.
Ultracapacitors have very high power density but very low energy density. Because of this reason, they are very good for transients.
Ultracapacitors can increase the life of batteries when used to handle transients.

Hence, the ultracapacitor is the best choice for vehicles that accelerate & decelerate very frequently.

From the above plot, we can say that

Lead-acid batteries have relatively low energy density.
Nickel Cadmium batteries have a much high energy density compared to lead-acid batteries.
Ni-MH batteries can have two to three times the capacity of NiCd batteries of the same size, with high significance and also much less than lithium-ion batteries.
Lithium-ion batteries have a high energy density.
Energy density is more in ultracapacitors compared to capacitors.

4. True. The electrode marked as (1) is the negative electrode.

The negative electrode is typically graphite and can be intercalated.
It doesn't contain any lithium initially since it is graphite.
During charging, the external potential is applied, and the lithium dissociates into lithium-ion, Li+ and electron.
During the discharge process, the reverse of this happens.
Once the graphite has enough lithium, when connected to the load, it powers the load.
The lithium inside the graphite releases electrons and moves back to the positive electrode.

Ship work like this
in your own course.