Energy is defined as the ability to do work. Primarily, it is the gift of nature to
the mankind. The consumption of energy is directly proportional to the progress of
mankind. The current energy needs are, however, very much dependent on nuclear
and fossil-fuel power [1, 2]. Nowadays, due to heavy industrialization, increase in
population, present fossil fuels will not last more than few decades to supply the
demand of electric power. Major sources of energy for our requirement in India are
non-renewable sources of energy like coal, petroleum, natural gas, water, nuclear and
wind. At present, most of the research is focusing on fossil fuels for our energy
requirements. Combustion of fossil fuels emits greenhouse gases into the atmosphere.
Global warming is a direct consequence of the accumulation of greenhouse gases.
Every year the energy demand is constantly increasing, mainly, due to the
increase in transportations. Moreover, the figure1.1clarifies the future energy demand
in account of considering the population and economic growth by an individual and
Nations. As a result of this, at the year 2035 the energy required would cross 700
quadrillion BTU (British Thermal Unit equivalent to ~2.19 x 10-14Mtoe). The
electricity plays an important role. It is produced by mainly hydro and thermal power.
Thermal power plants utilizes fuels mainly like coal and nuclear energy. The scarcity
of fuels and pollution make us to more concerns about adopting renewable energy
sources like tidal, wind and solar energy Internal combustion engines are a major source of CO2 emission.


In today's life, b
industrial appliances use
Alessandro Volta in 1800
the energy is stored in the
and wherever it is needed
also termed as galvanic
because their free energy
2
bal energy demand (source: EIA, Energy ou
table A2)
energy will be the greatest challenge for hum
ard, solar, wind, hydrothermal, geothermal, nu
idered. Among them, fuel cells, convert ch
ergy are environmentally friendly. Electrica
energy sources must be stored for continuou
ergy storage devices, among them, batter
ttention due to their higher power and energy
batteries play an important role as many
batteries as their power source. It was fir
0. Batteries are electrochemical storage devi
e form of chemical potential difference and u
d.