ELECTROCHEMICAL ENERGY SYSTEMS – MODULE 5
BASICS OF AN ELECTROCHEMICAL CELL
• Commonly referred to as voltaic or galvanic cell.
• An electrochemical cell is a device consisting of two electrodes, each in
contact with a solution of its own ions, and transforms the free energy
change of the redox reaction at the electrodes into electrical energy .
• Energy is the driving force for chemical reactions in electrodes.
• In a redox reaction, the energy released in the reaction due to the
movement of charged particles gives rise to a potential difference.
• The maximum potential difference is called the electromotive force (EMF),
E, in volts
• The more positive the cell potential, the greater the tendency for the
reaction to proceed to spontaneity.
CLASSIFICATION OF ELECTROCHEMICAL CELLS
GALVANIC CELL
• A device used to convert the chemical energy produced in a redox reaction
to electrical energy is called an electrochemical cell or chemical cell.
• The free energy change in a galvanic cell, or in a spontaneous cell reaction,
must be negative and the potential difference of the electrodes (cell
voltage) must be positive.
• Eg: Daniel cell
,ELECTROLYTIC CELL
• It is a device in which electrical energy from an external source can be used
to produce chemical reactions.
• Free energy change is +ve
• Eg: Electroplating of copper or nickel
ELECTROCHEMICAL SERIES
, • The lower the element, the greater the tendency to form anode.
BATTERIES
• Batteries use a chemical reaction to do work on charge and produce a
voltage between their output terminals.
• The basic element in a battery is called an electrochemical cell and makes
use of an oxidation/reduction reaction.
BASICS OF AN ELECTROCHEMICAL CELL
• Commonly referred to as voltaic or galvanic cell.
• An electrochemical cell is a device consisting of two electrodes, each in
contact with a solution of its own ions, and transforms the free energy
change of the redox reaction at the electrodes into electrical energy .
• Energy is the driving force for chemical reactions in electrodes.
• In a redox reaction, the energy released in the reaction due to the
movement of charged particles gives rise to a potential difference.
• The maximum potential difference is called the electromotive force (EMF),
E, in volts
• The more positive the cell potential, the greater the tendency for the
reaction to proceed to spontaneity.
CLASSIFICATION OF ELECTROCHEMICAL CELLS
GALVANIC CELL
• A device used to convert the chemical energy produced in a redox reaction
to electrical energy is called an electrochemical cell or chemical cell.
• The free energy change in a galvanic cell, or in a spontaneous cell reaction,
must be negative and the potential difference of the electrodes (cell
voltage) must be positive.
• Eg: Daniel cell
,ELECTROLYTIC CELL
• It is a device in which electrical energy from an external source can be used
to produce chemical reactions.
• Free energy change is +ve
• Eg: Electroplating of copper or nickel
ELECTROCHEMICAL SERIES
, • The lower the element, the greater the tendency to form anode.
BATTERIES
• Batteries use a chemical reaction to do work on charge and produce a
voltage between their output terminals.
• The basic element in a battery is called an electrochemical cell and makes
use of an oxidation/reduction reaction.
