Week 2 Challenge

Question 1:
Compare four different types of fuel cells and state their applications.

Sl No	Types of FC	Advantages	Challenges and Applications
1	Proton Exchange Membrane	It has Sloid electrolyte which reduces the corrosion. Has less temperature Has quick start up and load following	The catalyst is expensive and sensitive to the fuel impurities. Application: Most of the passenger and the transport vehicles.
2	Solid Oxide fuel Cell	Higher Efficiency Fuel Flexibility Solid Electrolyte Suitable for power and heating	High temperature leads to the corrosion and breakdown of the cell components Long start up time Application: Power Generation Purpose
3	Alkaline Fuel Cell	Lower Cost Components Low temperature Quick Start up	Sensitive to the CO2 in fuel and air electrolyte management Application: Low powered gadgets
4	Direct Methanol FC	Ease in fuel storage and delivery Low cost of methanol operation at low temp and pressure	Still emits CO2 Sluggish response Application: Most of the passenger car

Question 2:
Using a plot with energy density and power density on the X and Y axis, arrange various battery types like lithium ion, lead acid, Nickel Cadmium, Ultracapacitor, fuel cell.

The Energy density of a battery is generally expressed in two ways, in the form of gravimetric energy density and as volumetric energy density.

The gravimetric energy density or the specific energy of a battery is a measure of how much energy a battery contains in comparison to its weight and is typically expressed in Watt-hours/kilogram (W-hr/kg).

The volumetric energy density or the energy density of a battery is a measure of how much energy a battery contains in comparison to its volume and is typically expressed in Watt-hours/litre (W-hr/l).

For a given weight or volume a higher energy density cell chemistry will store more energy or alternatively for a given storage capacity a higher energy density cell will be smaller and lighter.

Generally higher energy densities are obtained by using more reactive chemicals. The downside is that more reactive chemicals tend to be unstable and may require special safety precautions. The energy density is also dependent on the quality of the active materials used in cell construction with impurities limiting the cell capacities which can be achieved. This is why cells from different manufacturers with similar cell chemistries and similar construction may have a different energy content and discharge performance.

Fuel Cells have the High Enegy density and the Low power density Therefore the fuel cells can give Better range.

Ultra capacitors Have the High power density and the low energy density therefore it can provide the peak power or the good acceleration.

Li-ion batteries performance lies between the FC and UC

So it is bettre to use the storage devices in combination for better acceleration and the better range.