Fuel cell

A fuel cell is a device that converts the chemical energy

from a fuel into electricity through a chemical reaction

with oxygen or another oxidizing agent .

Hydrogen is the most common fuel into electricity but hydrocarbon such as natural gas and methanol are used

sometimes as alternative .

Fuel cell

In secondary batteries, the chemical energy is stored in their electrodes . But in the fuel cells , the oxidants and the fuels are stored outside the cell.

Also they require constant source of fuel and oxygen to sustain the chemical reaction .This is the advantage of fuel cell over storage batteries because itb is possible to supply the fuels continously from outside and keep the fuel cell working practically forever.

Fuel cells produce water heat and a small quantity of nitrogen di oxide .

Individual fuel cells can produce about 0.7 volts . So they are stacked together to increase output of the cell.

They have an energy efficiency of 40-60% and it can be increased upto 85%.

First fuel cell was produced in 1838.

FEATURES OF FUEL CELLS

Back up powerPortable powerTransportationSpeciality vehiclesMilitary and space Electric utilityAuxillary powerDistributed generation

APPLICATIONS OF FUEL CELLS

Lithium is the lightest of metals and it can float on water.

The electrochemical properties of lithium are excellent and it is also a highly reactive material.

These properties gives Lithium the potential to achieve very high energy and power densities in high-density

battery applications such as automotive and standby power.

Lithium batteries are primary batteries in which lithiun metal (or) lithium compound acts as a Anode. A lithuim cell can produce voltage from 1.5 V to about 3 V based on the types of materials used.

Lithium Battery

1. Lithium batteries 2. Lithium-ion batteries

In lithium batteries, a pure lithium metallic element is used as anode. These types of batteries are not rechargeable.

In lithium-ion batteries, lithium compounds are used as anode.

These batteries are known as re-chargeable batteries. Therefore, Lithium ion batteries are considered as best than pure Lithium based batteries.

There are two types of lithium-based batteries available.

Li-ion batteries are secondary batteries.

The battery consists of a anode of Lithium, dissolved as ions, into a carbon.

The cathode material is made up from Lithium liberating compounds, typically the three electro-active oxide materials,

Lithium Cobalt-oxide (LiCoO2 ) Lithium Manganese-oxide (LiMn2 O4 ) Lithium Nickel-oxide (LiNiO2)

Lithium-ion battery (Li-ion Battery)

They have high energy density than other rechargeable batteries

They are less weight. They produce high voltage out about 4 V

as compared with other batteries. They have improved safety, i.e. more

resistance to overcharge No liquid electrolyte means they are

immune from leaking. Fast charge and discharge rate.

Advantage

They are expensive They are not available in standard cell types. Lithium batteries cannot be recharged. Once the

battery runs out, it has to be replaced. When lithium batteries are used in large number, the fact that they are not rechargeable can add to the cost.

These batteries can also be difficult to replace if they are embedded in electronics and may necessitate professional repair, or even replacement of the whole electronic item.

Dis advantages