Page 289 - Polymer-based Nanocomposites for Energy and Environmental Applications

Polymer nanocomposite materials in energy storage: Properties and applications 259

Fig. 9.5 Various forms of carbon nanomaterials for the electrode for EDLCs [188].
Reproduced with permission from Yan Q-L, Gozin M, Zhao F-Q, Cohen A, Pang S-P. Highly
energetic compositions based on functionalized carbon nanomaterials. Nanoscale 2016;8
(9):4799–851. Copyright (2016), the Royal Society of Chemistry.

EDLCs, replacing the activated carbon in literature. Some of the nanomaterials and
their structures are shown in Fig. 9.5. These nanomaterials show exciting prospects
for use as electrode for EDLCs; their advantages and disadvantages are summarized
in excellent review papers [25,180,182,186,189,190].
CNTs are nonporous carbon with quasi one-dimensional (1D) tubular structure
2
made by rolling up of one or more sp -hybridized graphite sheets leading to single-
wall carbon nanotubes (SWCNTs) and MWCNTs, respectively [191,192]. CNTs
showed promise as electrode material for EDLCs because of their high aspect ratio,
large surface area, excellent electric conductivity, and mechanical properties
[193,194]. They show moderate specific capacitance of 40–100 F g 1 [193,195].
Polymer conducting materials are very exciting for use in pseudocapacitor because
of their large theoretical specific capacitance and good electric conductivity, are envi-
ronmentally benign and easy to produce at commercial scale, are low cost
[16,21,22,25,29,120], and are flexible to buffer the stress due to expansion/contraction
during charging and discharging in processing. Fabricating polymer nanocomposite
with conducting polymers such as PANI and pyrrole has been used to induce pseudo-
capacitance to the electrode to improve the power and energy density of the pristine
CNTs. These polymer nanocomposites combine the properties of the polymers and the
CNT due to synergic effect. Conducting polymers have large theoretical specific
capacitance and excellent electric conductivity, can be produced at large scale, are
environmentally benign, and are low cost [25,29]. But they also show low cyclic life
because of the stability issues originating from the expansion/contraction during the
charging/discharging process [15,21,22,25,29,120]. Among the conducting polymers,
polyaniline (PANI) has attracted tremendous amount of research efforts for its use as
pseudocapacitive material for the supercapacitors because of its ease of synthesis