DIFFERENT TYPES OF

CELLS

BY :- NAVEEN KUMAR

K V LAKHANPUR

CELL CELL IS A DEVICE WHICH CONVERT CHEMICAL ENERGY INTO ELECTRICAL ENERGY AND VICE VERSA

TYPES OF CELLS

ELECTROCHEMICAL CELL:A DEVICE WHICH CONVERT CHEMICAL ENERGY INTO ELECTRICAL ENEGRY eg DRY CELL, ,ZINC CADMIUM CELL & FUEL CELL

ELECTROLYTIC CELL:-A DEVICE WHICH CONVER ELECTRICAL ENERGY INTO CHEMICAL ENERGY eg DOWNS CELL, CASTNER-KELLNER CELL

THE ELECTROLYTIC CELL

Electric current forces charges on electrodes

+++

–––

Na+Na+

Cl– Cl–

• Na+ takes up an electron: Na+(aq) + e– Na • Cl– gives up an electron: 2Cl–(aq) Cl2 + 2e– • Thus electricity continues to flow• Pure Na is deposited, Cl2 gas is produced

• Na+ is attracted to negative, Cl– to positive

DRY CELL

At anodezn-------------------zn2+

+2e-

At cathode2 MnO2+2NH4++2e---Mn2O3+H2O+2NH3( )NH3 IS CONSUMED IN COMPLEX FORMATION WITH Zn 2+ ION Zn2++4NH3 ---------------- [Zn(NH3)4}2+ -----------[Zn(NH3)4]Cl2

At anode

Zn-------------------Zn2+ +2e-

At cathode2 MnO2+2NH4++2e---Mn2O3

+H2O+2NH3( ) NH3 IS CONSUMED IN COMPLEX FORMATION WITH Zn 2+ ION Zn2++4NH3 --- [Zn(NH3)4}2+

-------- 2Cl------[Zn(NH3)4]Cl2

THE LEAD STORAGE BATTERY.

ELECTRODE REACTIONS IN LEAD STORAGE BATTERY

FUEL CELL

Cathode: O2(g) + 2H2O(l ) + 4e– → 4OH–(aq)⎯

Anode: 2H2 (g) + 4OH–(aq) → 4H2O(l) + 4e–⎯

OVERALL REACTION

2H2(g) + O2(g) → 2 ⎯H2O(l )

MERITS OF FUEL CELLECO FRIENDLYCONTINUOUS SOURSE OF ENERGYHIGH EFFICIENCY DEMERITS OF FUEL CELL VERY EXPENSIVEHEAVYNOT CONVENIENT TO USEHIGHLY CORROSIVE NATURE OF THE ELECTROLYTE

THANKS