Challenge

Week 5 Challenge

1. False

Battery pack has less specific power capacity than ultracapacitor.
To meet this amount of peak current, the battery has to designed as per this instant acceleration and braking.Hence the battery pack size and cost also increase.
For this scenorio instantaneous high power for short duration of time, it is not efficient to increase the battery pack.
But ultracapacitor has ten times high specific power than battery i.e., about 10kW/kg.
Ultra-capacitors can take care of peak loads.
Therefore sudden load can be used to meet sudden acceleration and braking.
Sudden braking produces high regenerative current. This current can be used to charge the battery but it is not efficiently used.
Ultracapacitor can be charged and discharged quickly.
So, this current can be used to charge the ultracapacitor.

2. A plot has been created cell voltage vs energy density

Lead Acid batteries: Lead-acid batteries have relatively low energy density.
Nickel-Cadmium Battery:Nickel Cadmium has a much higher energy density compared to lead-acid batteries.
Nickel-Metal Hydride Battery: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 battery:Lithium-ion batteries have a high energy density.
Ultracapacitor:Energy density is more in ultracapacitors compared to capacitors.

3. A plot has been created cell voltage vs power density

During discharge, the lithium ions from the negative anode moves through the electrolyte to gets intercalates to positive cathode.
In order the balance the charge, the electrons moves from the anode to cathode in the external circuit.
The lithium gets deposited in the cathode. Not all the lithium ions are flows to the cathode.
Because, if all lithium ions are extracted the structure of anode becomes reduced.
Hence it leads to degradation of battery.
During charging, external current is given to positive of the battery.
The lithium ions from the positive electrode diffuses through the electrolyte and gets intercalated to the negative anode.
The electrons flows in order to balance charge.
During all electrochemical process, the anode is negative and cathode is positive.
During first time of charging, the lithium ion from cathode gets attached to anode and it forms the inseparable layer on the anode.
It leads to formation of SEl. The anode gets decomposes if it comes in contact with the electrolyte.
This solid electrolyte formation protects the anode.

A battery has just been manufactured in the industry and has been connected to a charger for the first time. The electrode marked as (1) in the picture below is the negative electrode is true

Ship work like this
in your own course.