Page 279 - Polymer-based Nanocomposites for Energy and Environmental Applications

Polymer nanocomposite materials in energy storage: Properties and applications 251

chemical degradation in the presence of nonaqueous electrolytes [140]. Wu et al.
synthesized a composite 3,4,9,10-perylenetetracarboxylic dianhydride/carbon nano-
tube (PDTA/CNT) and its corresponding polymer nanocomposite, poly(3,4,9,10-
perylenetetracarboxylic dianhydride ethylene diamine)/carbon nanotube (PI/CNT),
by closed-tube polymerization. These two composites were used as organic cathode
materials for lithium-ion batteries. Compared with PTCDA, PTCDA/CNT exhibited
an enhanced rate capability, and the capacity was increased from 10 to 115 mAh g 1
at 2 C. Polymerization increased the cycling stability of organic cathode materials.
The capacity of the polymer nanocomposite PI/CNT remained at 93% after 300 cycles
1
under a current of 100 mA g , while the capacity of PTCDA/CNT was only 74%
after 300 cycles. The improved electrochemical properties of these materials were
ascribed to increased electronic conductivity of PTCDA due to the formation of com-
posites with CNTs and their decreased solubility in the electrolyte due to polymeri-
zation [24,141]. Sun et al. [142] used conjugated poly(1,5-diaminoanthraquinone)
(PDAA) as a redox organic polymer to make nanocomposite with graphene
nanosheets (GNS). The GNS provide self-supporting porous graphene foam, which
is intriguing and highly favored due to large accessible surface and integrated conduc-
tive network [85].
The 3D porous framework not only efficiently prevents the restacking of graphene
sheets but also endows them with high-rate transportation of electrons and electrolyte
ions [31,143]. The well-ordered graphene nanosheets/acid-treated multiwalled
carbon nanotube (GNS/aMWCNT)-supported 1,5-diaminoanthraquinone (DAA)
organic foams (oGCTF(DAA)) were attained by organic solvent displacement
method (forming graphene oxide/carbon nanotube organic colloids with DAA mono-
mers) followed by solvothermal reaction. Afterward, promising GNS/aMWCNT
organic foam-supported PDAA (oGCTF@PDAA) nanocomposites were obtained
by electrochemical polymerization based on oGCTF(DAA). Three-dimensional
porous GNS/aMWCNT organic foam-supported poly(1,5-diaminoanthraquinone)
(oGCTF@PDAA) nanocomposites showed a discharge capacity of 289 mAh g 1 at
1
30 mA g 1 current, whereas in the rapid charge/discharge conditions of 10 A g ,
1
it shows a capacity of 122 mAh g . It showed tremendous cyclic stability as even
after 2000 cycles, it could maintain 85.2% of its initial capacity even under high dis-
1
charge condition (10 A g )(Table 9.1).
Apart from the abovementioned materials, important polymer nanocomposite
materials have been prepared and tested for their suitability as cathode material for
lithium [148–151]. Some very recent results have been summarized by Pitchai
et al. [117],Xuetal. [118], and Myung et al. [90].

9.3.1.3 PNCs as anode material for the Li ion batteries
Since the first commercialization of the Li-ion battery in the 1990s, tremendous
amount of research efforts has been devoted to the development of novel materials
to function as anode, the negative electrode, for the Li-ion batteries. It is very well
known that the anode material primarily dictates the energy density, the power den-
sity, and the cycle life of the battery. State-of-the-art material for anode for Li-ion