@article { ISI:000329137400081, title = {Design of a high performance thin all-solid-state supercapacitor mimicking the active interface of its liquid-state counterpart}, journal = {ACS Applied Materials \& Interfaces}, volume = {5}, number = {24}, year = {2013}, month = {DEC}, pages = {13397-13404}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Here we report an all-solid-state supercapacitor (ASSP) which closely mimics the electrode-electrolyte interface of its liquid-state counterpart by impregnating polyaniline (PANO-coated carbon paper with polyvinyl alcohol-H2SO4 (PVA-H2SO4) gel/plasticized polymer electrolyte. The well penetrated PVA-H2SO4 network along the porous carbon matrix essentially enhanced the electrode-electrolyte interface of the resulting device with a very low equivalent series resistance (ESR) of 1 Omega/cm(2) and established an interfacial structure very similar to a liquid electrolyte. The designed interface of the device was confirmed by cross-sectional elemental mapping and scanning electron microscopy (SEM) images. The PANI in the device displayed a specific capacitance of 647 F/g with an areal capacitance of 1 F/cm(2) at 0.5 A/g and a capacitance retention of 62\% at 20 A/g. The above values are the highest among those reported for any solid-state-supercapacitor. The whole device, including the electrolyte, shows a capacitance of 12 F/g with a significantly low leakage current of 16 mu A(2). Apart from this, the device showed excellent stability for 10000 cycles with a coulombic efficiency of 100\%. Energy density of the PANI in the device is 14.3 Wh/kg.

}, keywords = {all-solid-state, cyclic voltametry, impedance analysis, polyaniline, polyvinyl alcohol, supercapacitor}, issn = {1944-8244}, doi = {10.1021/am404320e}, author = {Anothumakkool, Bihag and Torris, Arun A. T. and Bhange, Siddheshwar N. and Unni, SreeKuttan M. and Badiger, Manohar V. and Kurungot, Sreekumar} } @article { ISI:000368651100021, title = {High-Performance flexible solid-state supercapacitor with an extended nanoregime interface through in situ polymer electrolyte generation}, journal = {ACS Applied Materials \& Interfaces}, volume = {8}, number = {2}, year = {2016}, month = {JAN}, pages = {1233-1241}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

{Here, we report an efficient strategy by which a significantly enhanced electrodeelectrolyte interface in an electrode for supercapacitor application could be accomplished by allowing in situ polymer gel electrolyte generation inside the nanopores of the electrodes. This unique and highly efficient strategy could be conceived by judiciously maintaining ultraviolet-triggered polymerization of a monomer mixture in the presence of a high-surface-area porous carbon. The method is very simple and scalable, and a prototype, flexible solid-state supercapacitor could even be demonstrated in an encapsulation-free condition by using the commercial-grade electrodes (thickness = 150 mu m

}, keywords = {cyclic voltametry, impedance analysis, in situ polymer generation, interface, polymer electrolyte, supercapacitor}, issn = {1944-8244}, doi = {10.1021/acsami.5b09677}, author = {Anothumakkool, Bihag and Torris, Arun A. T. and Veeliyath, Sajna and Vijayakumar, Vidyanand and Badiger, Manohar V. and Kurungot, Sreekumar} } @article {44218, title = {Realizing high capacitance and rate capability in polyaniline by enhancing the electrochemical surface area through induction of superhydrophilicity}, journal = {ACS Applied Materials \& Interfaces}, volume = {10}, year = {2018}, month = {JAN}, pages = {676-686}, type = {Article}, abstract = {

Polyaniline (PANI) as a pseudocapacitive material has very high theoretical capacitance of 2000 F g(-1). However, its practical capacitance has been limited by low electrochemical surface area (ESA) and unfavorable wettability toward aqueous electrolytes. This work deals with a strategy wherein the high ESA of PANI has been achieved by the induction of superhydrophilicity together with the alignment of PANI exclusively on the surface of carbon fibers as a thin layer to form a hybrid assembly. Superhydrophilicity is induced by electrochemical functionalization of the Toray carbon paper, which further induces superhydrophilicity to the electrodeposited PANI layer on the paper, thereby ensuring a high electrode-electrolyte interface. The Toray paper is electrochemically functionalized by the anodization method, which generates a highly active electrochemical surface as well as greater wettability (superhydrophilic) of the carbon fibers. Because of the strong interaction of anilinium chloride with the hydrophilic carbon surface, PANI is polymerized exclusively over the surface of the fibers without any appreciable aggregation or agglomeration of the polymer. The PANI-Toray paper assembly in the solid-state prototype supercapacitor can provide a high gravimetric capacitance of 1335 F g(-1) as well as a high areal capacitance of 1.3 F cm(-2) at a current density of 10 A g(-1). The device also exhibits high rate capability, delivering 1217 F g(-1) at a current density of 50 A g(-1) and a high energy density of 30 W h kg(-1) at a power density of 2 kW kg(-1).

}, keywords = {electrochemical active sulfate area, electrochemical functionalization, electropolymerization, polyaniline, supercapacitor, superhydrophilic}, issn = {1944-8244}, doi = {10.1021/acsami.7b15534}, author = {Soni, Roby and Kashyap, Varchaswal and Nagaraju, Divya and Kurungot, Sreekumar} } @article {46164, title = {Synthesis of ultrathin PEDOT on carbon nanotubes and shear thinning xanthan Gum-H2SO4 gel electrolyte for supercapacitors}, journal = {ChemElectroChem}, volume = {6}, year = {2019}, month = {MAR }, pages = {1861-1869}, type = {Article}, abstract = {

Resistance of the electrode material play a vital role for applications in supercapacitors, where lowering the resistance leads to improved performance. Poly(3,4-ethylene dioxythiophene) (PEDOT) possesses high theoretical conductivity; however, the high density of grain boundaries, low accessible surface area, and low rate capability have been pervasive issues affecting the PEDOT-based supercapacitors. To this end, a hydrothermal method is proposed in this work where oxygen functional groups incorporated on the surface of carbon nanotubes (CNTs) are utilized to polymerize 3,4-ethylenedioxythiophene (EDOT). PEDOT forms an ultrathin, well-aligned coating on the surface of CNTs. This arrangement minimizes the number of grain boundaries and increases the electrochemically active surface area. Additionally, a shear-thinning Xanthan gum-H2SO4 gel electrolyte is introduced to overcome the low impregnation of the conventional polyvinyl-based electrolyte due to the hydrophobicity of the CNT-PEDOT composite. A supercapacitor based on this material showed a very low Equivalent Series Resistance (ESR) of 0.31 which leads to a high power density of 74 W cm(-3).

}, keywords = {gel electrolyte, PEDOT, shear thinning, supercapacitor, xanthan gum}, issn = {2196-0216}, doi = {10.1002/celc.201801780}, author = {Soni, Roby and Bhange, Siddheshwar N. and Athira, E. and Chetry, Rashmi and Kurungot, Sreekumar} } @article {47434, title = {Biomass-derived activated carbon material from native European deciduous trees as an inexpensive and sustainable energy material for supercapacitor application}, journal = {Journal of Energy Storage}, volume = {34}, year = {2021}, month = {FEB}, pages = {102178}, type = {Article}, abstract = {

Activated carbons are one of the possible electrode materials for supercapacitors (SCs), which are widely used in commercial applications. Herein, we reported the synthesis of a novel activated carbon derived through a cavitation process from the mixture of native European deciduous trees, Birch, Fagaceae, and Carpinus betulus (commonly known as European hornbeam), which was employed as the electrode material in SC. From the morphological and structural characterization, we observed that the prepared sample is a desirable carbon with good porosity and high specific surface area of about 614 m(2) g(-1). The electrochemical properties of the synthesized material were evaluated with a three-electrode configuration in 1.0 M H2SO4 electrolyte. It was found that in device mode, the carbon material delivers a specific capacitance of 24 F g(-1) at 0.25 A g(-1) with excellent cycling stability of over 10000 consecutive charge/discharge cycles. Thus, our studies demonstrate the facile synthesis of biomass-derived carbon and its application as a versatile electrode material for SC applications.

}, keywords = {Biomass, Carbon material, Deciduous trees, Electrode material, supercapacitor}, issn = {2352-152X}, doi = {10.1016/j.est.2020.102178}, author = {Jain, Amrita and Ghosh, Meena and Krajewski, Marcin and Kurungot, Sreekumar and Michalska, Monika} }