Page 214 - Polymer-based Nanocomposites for Energy and Environmental Applications

186 Polymer-based Nanocomposites for Energy and Environmental Applications

electrode/electrolyte interfaces, and (ii) pseudocapacitance, which tends to have rapid
and reversible redox reactions at the materials surface [8,9].
Usually, transition metal oxides/hydroxides and conducting polymer (CP) are the
active electrode materials used in the progress of pseudocapacitors, whereas the car-
bonaceous materials such as graphene [10], activated carbon [11,12] carbon aerogels
[13], xerogels [14], carbon nanotubes [15–18], mesoporous carbon [19], and carbide-
derived carbons [20] have been widely investigated in EDLCs. These studied mate-
rials normally display respectable electrochemical stability but imperfect EDLCs. CP
such as polyanilines (PANIs) [21–24], polypyrrole (PPYs) [25–27] and polythiophenes
(PTs) [28–31], and metal oxides/hydroxides/phosphates [32–35] have been inves-
tigated for energy storage devices.
Conversely, the poor stability of CP has limited the usage in developing these mate-
rials to devices. It is essential to develop the materials based on combining the differ-
ent materials to advance the performance. These combined composite materials tend
to have enhanced stability [36,37] due to the synergetic effect of carbonaceous mate-
rials and high pseudocapacitance of the CP. It is considered to be a powerful method to
overwhelming the technical blockages to fabricate the electrode materials. The com-
monly used materials for nanocomposite synthesis include carbon-based materials
like activated carbon [38–40], silica [41,42], sands [43,44], and polymers [45–50].
Among these, polymer-based materials are considered to be appropriate candidate
due to their manageable pore space, surface chemistry, and attractive mechanical
strength. The resultant polymer-based nanocomposites (PNCs) hold the characteristic
phenomenon of nanoparticles, whereas the polymer-based electrode materials offer
greater stability, ability, and synergetic effects produced by the interaction of nano-
particle and matrix.
The commonly used nanoparticles are based on zero-valent metals [51], metallic
oxides [52], biopolymers [53], and single enzyme particles [54]. These various range
of the nanoparticles can be loaded onto porous resins [55], cellulose [56], chitosan
[57], and alginate [58]. The selection of the polymeric supports is generally directed
by its mechanical and thermal behaviors. This characteristic of techniques has pro-
spective applications in the field of engineering plastics, polymer-based materials,
rubbers, adhesives, and coatings [59]. Due to its uniqueness, PNCs possess astonish-
ing hybrid behaviors synergistically observed from two components. In this chapter,
various kinds of PNCs and its energy storage and environmental applications will be
discussed. Moreover, energy storage mechanism of PNCs in supercapacitors and bat-
teries will be highlighted.

6.2 Polymer-based nanocomposites for
energy storage applications

The rising demands for energy and environment pollution and depletion of natural
resources have gained the researchers’ considerations concerning the development
of clean energy system for the energy conversion and storage devices. Another sub-
stitute energy source is electrochemical energy production. In order to overcome these