Week 5 Challenge

Question 1:

Aim : To 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:

• Here the given scenario is false This Because .
• The drivers driving pattern can be concluded here as short power transients.
• So here Driver is accelerating and we all know how the power demand shoots up at the time of acceleration though for a short time.
• we can see in the below graph
• Pa here represents the acceleration power.
• This power is only needed when we are accelerating.
• So It is still dominant amongst all even though we need this power for short time only.

• Here the Battery can supply this demand but the cost of manufacturing such batteries is extremely high.
• On the other hand ultracapacitor holds very high power which it releases on demand and it can get charge quickly too.
• This quality of having high power density makes the ultracapacitor a perfect choice of power source for such transient power demands.

Question 2:

Aim : To 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.

Answer :

Plot of Energy density Vs cell voltage is shown below;

1) Ultracapacitor:

• Here It can be seen that UC cannot be used for high energy demanding applications.
• So Its voltage is greater than that of Lead acid NiCd and NiMH.
• Then They are widely used in Electric or hybrid vehicles to provide a quick burst of acceleration over short distances or to start the main motor.

2) NiMH & NiCd:

• Here the Nickel metal hydride and Nickel cadmium have almost similar cell voltage value but energy density of NiMH is very high than NiCd.
• So by this reason the NiMH batteries are highly recommend in applications that call for long duration but not a high ampere load.
• Nicd are best suitable for portable power application.

3) Lead-acid:

• The lead acid batteries has low energy density as compared to NiMH and NiCd but cell voltage value is high.
• The Lead acid batteries are used in emergency lighting and to power sump pumps in case of power failure.
• So They were the first choice of energy in BEV.
• But now they have been replaced by other batteries cause they require frequent maintenance.

4) Lithium-ion:

• There are many types of lithium ion battery.
• Which They are mainly classified on the basis of cathode material used cause anode remains same in all the cases.
• But In plot we have shown the average energy density of it.
• Now li-ion is widely used in EVs mobile phones and many more applications.
• So They rule the above plot cause they have high energy density and high cell voltage as well amongst all.

5) Ultra capacitor:

• The ultracapacitor also called a super capacitoris an electrical component capable of holding hundreds of times more electrical charge quantity than a standard capacitor.
• So This characteristic makes ultracapacitors useful in devices that require relatively little current and low voltage.

Question 3:

Aim : For the above-mentioned components on the same plot retain the previous plot created in the previous

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

Answer:

Power density on the X axis and cell voltage on the Y axis;

• Here there is very less data available related to the power densities of above shown ESS.
• So Generally the values lies between a certain range but the plot shown above represents the average value.
• So here we Clearly we can see the Ultracapacitor as high.
• They are ploted with the following componets
• Lead acid battery
• Nickel cadmium battery
• Nickel Metal hydride battery
• Lithium ion battery
• ultra capcitor

Question 4:

Aim : To 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:

• Here we can say that the given condtition is true.
• This is why because here electrons are negatively charged and so are attracted to the positive end of a battery and repalled by the negative end.
• So when the battery is goes up to something that lets the electrons flow through it they flow from negative to positive.

• Here During charging process the positive electrode cathode loses the electron and this electron travels to the anode as a reverse voltage is apllied to the battery.

• But We should remember that in almost all the electronics devices cathode is -ive and anode is +ive but battery being the active material has cathode termed as +ive and anode as negative.

• So by this reason the behaviour of electrodes in batteries is explained in two ways i.e while charging and discharging. Below fig shows what has been theoretically thought