Week 5 Challenge

Question 1:

Consider a scenario where an aggressive driver is accelerating very rapidly and braking harshly in a city driving. Is battery better a choice to supply power than UC in this scenario?

1. True
2. False

Why?

Answer:

The above is the false statement and the reason for that is stated below.

Battery is not a better choice where an aggressive driver is accelerting very rapidly and braking harshly in a city driving scenario.the instanous power which shoul be provided by the source need to be high.The ability of the source to provide instantanous power is determined by th power by the power density instantaneous power is determined by th power density(or specific power) parameter of the source.The battery has low powew density compared to the Ultracapacitor.The power density of the capacitor can be more than 10 times that of battery,so during these types of scenerio powering the drivetrai n by Ultracapacitor is recommended.

The power density of the battery and the Ultracapacitor is given below.

Question 2:

Consider the following components.

1) Lead acid battery 2) Nickel cadmium battery 3) Nickel Metal hydride battery 4) Lithium ion (specify chemistry) battery 5) Ultra Capacitor

Note: In case of a range of energy density, take the average value for the plot.

Create a plot with energy density on the X Axis and cell voltage on the Y axis.

Comment on the capabilities of these batteries based on the plot created.

Energy Density: It is the measure of how much energy a battery contains in proportion to its weight.This measurement is typically presentated in watt-hours/kg.The higher the energy density,the longer the run time.

Lead Acid Battery: it has high energy density.

Nickel Metal Hydride Battery:Ni-MH batteries can have two or three times the capacity of NiCd batteries of the same size with the high significance and aslo much less than of lithium ion batteries.

Lithium Ion Battery:Have high energy density

Ultra Capacitor:Energy density is more in ultracapacitors compared to capacitors.The values of energy densities of different batteries and cell voltages are shown in the below table and aslo the same is represented in X-Y plot the shown below.

Nickle cadmium battery:High energy density compared to lead acid batteries.

Question 3:

For the above-mentioned components on the same plot (retain the previous plot) created in the previous

Create a plot with power density on the X axis and cell voltage on the Y axis.

Ans:

The Power density of the above set of batteries is shown below.

battery name	Power Density	Cell Voltage
Lead Acid Battery	180	2.1
Nickel Cadmium	150	1.2
Nickel Metal Hydraide	1000	1.2
LITHIUM ION	340	3.6

Question 4:

Consider the following scenario:

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.

1. True
2. False

Answer:True,During charging the Li ions moves from Cathode to anode through seperator which is a ionic conductor,

During charging the DC source is connected such that a positive potenial is created between the cathode and source this will attract the e- from the cathode and causes the lithium metal oxide to spilt into metal oxide to spilt into metal oxide,li+ ions and e - are intercalated in the graphite.This causes the Li cell to reach unstable state as it progress the potential difference between the anode and cathode increases.

During discharge Li+ ions moves from Anode to Cathode as the potential difference is high,when the external load is connected it creates a path such that the e- flows through external and Li + ions through seperator and combine with metal oxide to form Lithium Metal Oxide.

Charging following reactions:

The positive electrode half reaction in the li doped cobalt oxide

The Negetive electrode half reaction in the li-doped cobalt oxide substrate is

The Full Reaction

The negetive electrode half reaction for graphite is

The Full Reaction is