Page 215 - Polymer-based Nanocomposites for Energy and Environmental Applications

Polymer-based nanocomposites for energy and environmental applications 187

issues, in recent years, electrochemical energy storage devices mostly include batte-
ries and electrochemical supercapacitors. It is necessary to develop the PNC materials
built on these unlike materials for attaining superior behaviors. These nanocomposite
materials display enhanced stability [60,61] credited to the combined effect of the tre-
mendous conducting and mechanical behavior of carbonaceous materials and high
pseudocapacitance of the CP. This section provides general information on the various
CP nanocomposite materials for energy-related applications with current develop-
ments in this area. With continuous growths of electronic technologies, research in
electrochemical supercapacitors technology developed pseudocapacitors and asym-
metrical supercapacitors. This segment discusses about the energy storage behaviors
behind classical conventional capacitors and the different kinds of electrochemical
supercapacitors.

6.2.1 Energy storage mechanism in supercapacitors and batteries
In conventional capacitors, energy is generally stored in dielectric materials among
two electrically conducting electrodes. When we induce the potential difference
between the electrodes, energy is stored on the opposite plates that can accumulate
equal amount of positive and negative charges as displayed in Fig. 6.1. Capacitance
is direct estimation of the storage energy and is directly related to the electrode surface
area and inversely related to the distance between the electrodes. Capacitance (C)is
dignified in farad (F) and can be obtained by

A ∗ ε
C ¼ (6.1)
D

Dielectric (e) Fig. 6.1 Organization of charges in a
dielectric material through the
charged state of classical
+ − conventional capacitors.
+ − Plates
+ − (A)
+ + − −
+ −
+ −
+ −
+ −
+ −
+ −
+ −

(d)