Asymmetric supercapacitor containing poly(3-methyl thiophene)-multiwalled carbon nanotubes nanocomposites and activated carbon
Highlights
► Poly(3-methylthiophene) (PMT)-multiwalled carbon nanotubes (MWCNT) nanocomposites prepared chemically. ► Specific capacitance of nanocomposite at 12.5 wt% loading of MWCNT was 68% higher than pure PMT. ► Hybrid supercapacitors based on nanocomposites and activated carbon fabricated with optimized mass loading. ► Supercapacitors exhibited enhanced rate capability and electrochemical stability with increase in MWCNT concentration in the nanocomposite.
Introduction
Supercapacitors are electrochemical devices which are used for pulse power applications. They find applications in electric vehicles, uninterrupted power supplies, memory backups, mobiles, cameras, etc. [1], [2], [3]. Based on electrode material, supercapacitors can be classified into electric double layer capacitors (EDLC) and pseudocapacitors [4], [5]. In EDLCs, charge separation takes place at the electrode/electrolyte interface and the energy storage mechanism is electrostatic in nature. The commonly used EDLC materials are activated carbon (AC), carbon nanotubes (CNT), graphene and carbon xerosols [6], [7], [8], [9], [10], [11]. In pseudocapacitors, fast reversible faradaic reaction takes place at the electrode/electrolyte interface. Conducting polymers and metal oxides are commonly used pseudocapacitance materials [12], [13], [14], [15], [16], [17]. In conducting polymers, the whole bulk of the polymer can be utilized for energy storage and hence, generally conducting polymers have higher specific capacitance [15], [16]. Besides these, conducting polymers have several other advantages like low cost, environmentally friendly, high conductivity in doped state, wide voltage window, high storage capacity and adjustable redox activity through chemical modification [17].
Conducting polymers in n-doped state exhibit lower conductivity and poorer stability than p-doped state [18], [19], [20], [21], [22]. Hence asymmetric supercapacitors were developed, where n-doped polymer is replaced by activated carbon or lithium intercalating compounds in order to improve stability and cycling performance compared to symmetric supercapacitors [5], [6]. Poly(3-methyl thiophene) (PMT) is an important conducting polymer which is studied as the electrode materials in both symmetric as well as asymmetric supercapacitors [23], [24], [25], [26], [27], [28], [29], [30], [31]. Mastragostino and group compared PMT based symmetric supercapacitors with asymmetric supercapacitor (PMT-AC) and achieved specific capacitance of 240 F g−1 for PMT and 39 F g−1 for total active material [23], [24], [25], [26]. Laforgue et al. fabricated 3 V-prototype asymmetric supercapacitor containing PMT and AC respectively. The device exhibited specific capacitance of 35 F g−1 for the total composite material while the specific capacitance of PMT was 230 F g−1 [27]. Arbizzani et al. studied PMT with ionic liquids and reported specific capacitance of 250 F g−1 at 60 °C [28]. Hybrid supercapacitor containing poly(ethylene oxide) based gel electrolyte, with PMT as the positive electrode was also reported and the supercapacitor exhibited specific capacitance around 18 F g−1 of total active material [29]. Hashmi et al. used different gel polymer electrolytes for PMT–PMT and PMT–polypyrrole (PPY) supercapacitors and reported discharge capacitance of 8–15 mF cm−2 [30]. PMT was electropolymerized on porous poly(vinylidine fluoride) (PVDF) membrane and the composites membrane exhibited discharge capacitance of 82 F g−1 [31].
Generally in conducting polymers, most of the pseudocapacitance are obtained from the surface redox reactions and therefore only a very thin surface layer undergo faradaic reaction [5], [31]. Moreover during doping and undoing, conducting polymers undergo volume change and hence are bound to undergo mechanical degradation which results in capacitance decay. These drawbacks can be minimized either by controlling polymer morphologies like nanorod formation or by nanocomposite formation using carbon nanotubes (CNTs), graphene [32], [33], [34], [35], [36], [37], [38], [39]. It is demonstrated that nanocomposites of conducting polymers have enhanced specific capacitance, cycling stability and conductivity.
Reports on PMT nanocomposite electrode materials for supercapacitor application are scantly. Xiao et al. utilized PMT-multiwalled carbon nanotubes (MWCNT) nanocomposites as the positive electrode in supercapacitor in voltage window of 0–1 V [40]. Kim et al. used PMT-MWCNT nanocomposites as the cathode material in lithium metal polymer battery [41]. Zinc ion doped PMT-MWCNT composites were studied for aqueous electrolyte based supercapacitor by Karthikeyan et al. [42]. However, detailed analysis of PMT-MWCNT nanocomposites for non aqueous supercapacitor has not been reported earlier. In this paper, PMT-MWCNT nanocomposites were prepared by in situ chemical method and their physical and electrochemical properties were studied. Also, we report electrochemical performance of hybrid supercapacitor based on PMT-MWCNT nanocomposites and AC, containing optimized mass ratio of the electrodes.
Section snippets
Materials
3-Methyl thiophene was obtained from Acros Chemicals, India. Ferric chloride, chloroform, methanol and hydrazine hydrate (SdFine Chemicals, India), MWCNT Grade:Nanocyl 3100 (Nanocyl, Begium, surface area: 300 m2 g−1), electrolytic grade propylene carbonate (PC) (Merck) were used without future purification. Activated carbon used in this study was obtained from PICA, France (grade: BP 10, surface area: 1900 m2 g−1). Tetra ethylene ammonium tetrafluroborate (TEABF4) (Alfa Aser) was thoroughly dried
TEM of nanocomposites
TEM micrographs of the PMT nanocomposites are shown in the Fig. 1. The micrographs of the nanocomposites reveal wrapping of PMT around MWCNT. The thickness of the PMT layer around MWCNT decreases with increase in MWCNT concentration in the nanocomposite. During in situ preparation of nanocomposites, the monomer concentration was kept constant while that of MWCNT increased. Obviously, as the heterogonous surface available during polymerization increases, the wrapping layer thickness wrapping
Conclusions
PMT-MWCNT nanocomposites with varying concentration of PMT have been prepared by chemical method. TEM analysis reveals that the PMT get wrapped around MWCNT and thickness of wrapping around MWCNT depends upon the concentration of PMT in the nanocomposites. TGA analysis shows that nanocomposites have higher thermal stability than pure PMT. Strong interaction between MWCNT and PMT is evidenced by Raman spectroscopy and XRD. PMT87.5 nanocomposite shows specific capacitance of 296 F g−1. The increase
Acknowledgements
The authors express their sincere thanks to Dr. R.S. Hastak, Director, NMRL Ambernath, for his encouragement and permission to publish this article. We would also like to acknowledge Sophisticated Analytical Instrumentation Facility (SAIF), IIT Bombay for Raman Spectroscopy and TEM experiments.
References (58)
Ultracapacitors: why, how and where is the technology
Journal of Power Sources
(2000)- et al.
Carbon properties and their role in supercapacitors
Journal of Power Sources
(2006) Nanocrystalline oxide supercapacitors
Materials Chemistry and Physics
(2002)- et al.
Conducting polymers as active materials in electrochemical capacitors
Journal of Power Sources
(1994) - et al.
A study of the electrochemical properties of conducting polymers for applications in electrochemical capacitors
Electrochimica Acta
(1994) - et al.
Conducting-polymer-based supercapacitor devices and electrodes
Journal of Power Sources
(2011) - et al.
Polythiophene-based supercapacitors
Journal of Power Sources
(1999) - et al.
Chemical synthesis and characterization of fluorinated polyphenylthiophene: application to energy storage
Synthetic Metals
(2001) - et al.
Poly(3-methyl thiophene)/PVDF composite as an electrode for supercapacitors
Journal of Power Sources
(2006) - et al.
Polymer based supercapacitors
Journal of Power Sources
(2001)
New trends in electrochemical supercapacitors
Journal of Power Sources
Electrode materials for ionic liquid-based supercapacitors
Journal of Power Sources
Polypyrrole and poly(3-methylthiophene)-based solid state redox supercapacitors using ion-conducting polymer electrolyte
Solid State Ionics
Morphological and electrochemical characterization of a poly(3-methylthiophene)/PVDF composite
Electrochimica Acta
Achieving high electrode specific capacitance with materials of low mass specific capacitance: potentiostatically grown thick micro-nanoporous PEDOT films
Electrochemistry Communications
Determination of the specific capacitance of conducting polymer/nanotubes composite electrodes using different cell configurations
Electrochimica Acta
Polyaniline/single-wall carbon nanotubes (PANI/SWCNT) composites for high performance supercapacitors
Electrochimica Acta
Polypyrrole/carbon nanotube nanocomposite enhanced the electrochemical capacitance of flexible graphene film for supercapacitors
Journal of Power Sources
Synthesis of mesoporous polythiophene/MnO2 nanocomposite and its enhanced pseudocapacitive properties
Journal of Power Sources
The study of multiwalled carbon nanotube deposited with conducting polymer for supercapacitor
Electrochimica Acta
Cycling performance of lithium metal polymer cells assembled with ionic liquid and poly(3-methyl thiophene)/carbon nanotube composite cathode
Journal of Power Sources
Electrochemical storage of energy in carbon nanotubes and nanostructured carbons
Carbon
Capacitance properties of poly(3,4-ethylenedioxythiophene)/carbon nanotubes composites
Journal of Physics and Chemistry of Solids
Mathematical functions for optimisation of conducting polymer/activated carbon asymmetric supercapacitors
Journal of Power Sources
All solid supercapacitor based on polyaniline and crosslinked sulfonated poly[ether ether ketone]
Electrochimica Acta
Modifacation of Al current collector surface by sol–gel deposit for carbon-carbon supercapacitor applications
Electrochimica Acta
High power density electrodes for carbon supercapacitor applications
Electrochimica Acta
Electrochemical Supercapacitors, Scientific Fundamentals and Technological Applications
Principles and applications of electrochemical capacitors
Electrochimica Acta
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