Abstract
Nanofiller-doped polymer electrolyte-based electrochemical devices are
now emerged as a novel material for electrochemical devices. This paper
reports a solid polymer electrolyte film doped with a new nanofiller
synthesized by the solution casting technique. Electrical, Optical, and
photoelectrochemical characterization are presented in detail.
Electrochemical impedance spectroscopy (EIS) shows with the dispersion
of nanofillers conductivity increases attains maxima and decreases. The
maximum conductivity was at 0.05 wt% nanofiller concentration of 3.25 x
10-5 S/cm. The calculated ionic transference value was
0.92 which shows the domency of the system as ionic. The linear sweep
voltammetry confirms a high electrochemical stability window (ESW) of
4.01V. Sandwitched electrical double-layer capacitors (EDLC) has been
developed using carbon-based electrodes and sandwitched nanofiller
dispersed polymer electrolyte, showing a high specific capacitance value
of ~ 200 F/g.
Keywords— Polymer electrolyte, Conductivity, Nanocomposite
polymer electrolyte, Supercapacitors
Introduction:
Nanofiller as dispersoid in polymer electrolytes is a known established
system playing a dominant role in day-to-day devices[1–3].
Nanofiller with polymer electrolyte matrix plays a dual role in the
sense one side enhances electrical conductivity (σ) by establishing a
quantum size effect, other side enhances mechanical stability of an
atom[4–7]. The ionic conducting polymers, known as Solid polymer
electrolytes [SPE] , that has been extensively researched and
produced since the 1970s. Wright first described ionic conductivity in
polyethylene oxide (PEO)/salt compounds in 1973[8]. In 1979, Armand
claimed that at temperatures between 303K and 353K, the electrical
conductivity of PEO/salt complexes might reach 10-5 S
cm-1. [9]. Polymer electrolytes have been
developed primarily for Li+ and Na+ions, two of the most common and abundant alkali metal ions.
In this study, we focus on the polymer-salt electrolyte combination PEO:
NaI in which the conductivity results from the conduction of Na+ ions.
PEO compounds with NaPF6 [10], NaSCN, NaI, and
NaCF3SO3 were the subject of earlier
work on Na+ ion conducting polymeric electrolytes [11].
Additionally, the sodium batteries that use these electrolytes are
rechargeable solid-state devices [12], [13]. A polymer
electrolyte of poly (ethylene oxide) and sodium iodide (PEO-NaI) has
been demonstrated to conduct Na+ ions and to some extent anionic
conduction. To enhanced the conductivity of PEO-based electrolytes at
lower operating temperatures, researchers proposed multiple techniques
to incorporate nano-scale an inorganic fillers, that includes
SiO2 [14], Al2O3[15], TiO2 [16], ZnO [17], ZrO [18],
CeO2 [19], and CuO [20], without involveing the
other physical properties, such as electrolyte reactivity towards
electrode, mechanical stability, etc [21,22].
In MXene multilayer nanoflake doped polymer electrolyte, we have tried
to develop a new nanofiller i.e.
Ti3C2Tx MXene doped
polymer electrolyte system. Polymer electrolyte chosen as host PEO:NaI
in which maxima in ionic conductivity was reported at 12 wt % sodium
iodide (NaI) concentration 1.05 x 10-7 S/cm. We have
dispersed MXene at various wt%. (i.e., 0.01% to 0.07%). These
multilayer nanoflake polymer electrolytes were systematically
characterized by various characterization tools and their results are
summarized in present paper.
Experimental Details:
Material and Method :
The polymer PEO with an average molecular weight of 100,000 was
purchased from ADRICH Chemistry Pvt. Ltd. in USA, while NaI (extra pure)
with a molecular weight of 166.01 g/mol was purchased from FINAR
Reagents Pvt., India.
Ti3C2Tx MXene multilayer
nanoflake having molecular weight of 167.62g/mol was purchased from
Nanoshel UK Limited with purity of 99.9%. Before use, the multilayer
nanoflake and other solvents utilized in this investigation were
thoroughly dried.