Chemistry in batteries. sandeepPresentation Transcript
Sandeep O. kharwar
A lot happens inside a battery when you pop it
into your flashlight , remote control or other
wire free device.
They produce electricity differ from battery to
Battery produce electricity due to
electromagnetic reaction between anode,
cathode and electrolyte while anode
experiences an oxidation and cathode
experiences reduction reaction.
Modern batteries use variety of chemical to
power their reaction.
1) Zinc-carbon battery:-In this anode is zinc and
cathode is manganese dioxide and electrolyte
is ammonium chloride or zinc chloride.
2) Alkaline battery: It gets its name from the
potassium hydroxide electrolyte ,which is an
3) Lithium-ions battery (rechargeable): This is
used in cell phones , digital cameras and even
4) Lead-acid battery : This is the chemistry used
in typical car battery .
Chemistry of Battery :Chemistry is the driving
force behind the magic of battery.
A battery is package of one
or more galvanic cells used for
the production and storage of
electric energy by chemical means.
A galvanic cell consist of
at least two half cells, a reduction
cell and an oxidation .
A galvanic cell is also
called a voltaic cell. The
spontaneous reaction in it
provide the electric or current .
Two half cells can be together to
form an electrolytic cell, which is
used for electrolysis used to force
no spontaneous chemical reaction
reaction: Many definition can be
oxidation and reduction reaction. in term of
electrochemistry, loss of electron is oxidation and gain
of electrons is reduction.
Oxidation and reduction cannot be carried out
separately , they have to appear together in a chemical
reaction. Thus the reaction called “Redox Reaction”. In
redox reaction Reducting and Oxidizing agent form
redox couple as they undergo the reaction: * oxidant
+ne- reductant e.g Cu(+2) + 2e- = Cu
* reductant oxidant +ne-. E.g Zn = Zn(+2) + 2e-
element or compound ,but of different
Example : Copper –zinc voltaic cells-
When a stick of zinc is inserted in a salt solution,
there is tendency for Zn to lose electron according to
the reaction ,
“ Zn=Zn(2+) +2e- ”
This arrangement of a Zn electrode in solution
containing Zn(2+) ions is a half cell, which
“ Zn/Zn(2+) ”
In this zinc metal and Zn(2+) ions form a redox
couple Zn(2+) being the oxidant and Zn the
Similarly , when a stick of copper is inserted in a copper salt
solution there is tendency for “Cu” to lose electron according
to reaction “ Cu = Cu(2+) + 2e- “ redox couple represented
However tendency of Zn to lose electron is stronger than
that of Cu , when two cells are connected by salt bridge to
form a closed circuit for electron so that copper actually gain
electron to become copper metal and redox reaction
represented as “ Cu(2+) + 2e- = Cu ” this arrangement is
called galvanic cell , this battery represented as
“Zn/Zn(2+)//Cu(2+)/Cu” in which two vertical line
represent a salt bridge and single line represent the
boundary between the two phase .