Swapnil S. Karade

MoS2 ultrathin nanoflakes for high performance supercapacitors: room temperature chemical bath deposition (CBD)

Homogeneous ultrathin nanoflakes of MoS2 thin films have been successfully developed by simple and low cost room temperature chemical bath deposition (CBD) method which further applied as electrode material for high-performance supercapacitors. The surface morphological analysis revealed uniform growth of MoS2 nanoflakes on whole substrate surface. Structural analysis confirms the formation of rhombohedral crystal structure of MoS2. The electrochemical performances were tested by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance techniques. Different electrolytes were tested in order to find suitable electrolyte for MoS2 thin films. In addition, the effect of electrolyte concentrations on supercapacitive properties of MoS2 thin film was investigated. Thus, MoS2 ultrathin nanoflakes electrode exhibits excellent electrochemical performances with maximum specific capacitance of 576 F g−1 at 5 mV s−1 and good cycling stability of 82% over 3000 cycles.

Anchoring cobalt oxide nanoparticles on to the surface multiwalled carbon nanotubes for improved supercapacitive performances

The present work explored a novel, simple and low cost ‘dipping and drying’ process followed by a successive ionic layer adsorption and reaction (SILAR) method for the synthesis of cobalt oxide anchored multiwalled carbon nanotubes (Co3O4/MWNTs). Initially, MWNTs have been coated on a stainless steel substrate by a simple ‘dip and dry’ method, on which further deposition of cobalt oxide nanoparticles was carried out by the SILAR method. Our results confirm the uniform coating of Co3O4 nanoparticles having sizes less than 15 nm on the surface of MWNTs. Later, the electrochemical performance shows that, the Co3O4/MWNTs films exhibit a maximum specific capacitance of 685 F g−1 in a 2 M KOH electrolyte at a scan rate of 5 mV s−1 with high cycle stability of 73% over 5000 cycles. Moreover, lower electrochemical equivalent series resistance (11.25 mΩ) give rise to the superior performance. These results show, the potential of Co3O4/MWNTs composite electrodes in electrochemical supercapacitors.

First report on a FeS-based 2 V operating flexible solid-state symmetric supercapacitor device

A high specific energy and specific power can be attained for the supercapacitor devices with the aid of optimum potential. The use of a flexible approach employing a solid-state device structure is always beneficial for advanced technological applications. Hence, effort has been made towards the fabrication of a complete solid-state symmetric and flexible supercapacitor device based on environmentally friendly and abundant iron sulfide as an electrode material, which has been obtained using a successive ionic layer adsorption and reaction method operated at room temperature (27 °C). An operating voltage of 2 V was achieved for the flexible device with a bending stability of 100% over a bending angle of 175° along with the LED glow working model. These outcomes can give new vision towards the construction of solid-state and flexible devices using a simple and low-cost method with potential ability towards roll-to-roll technology for commercialization.

First report on solution processed α-Ce2S3 rectangular microrods: An efficient energy storage supercapacitive electrode

Rectangular shaped α-Ce2S3 microrods have been grown with the aid of a facile, efficient, low cost and low temperature chemical bath deposition (CBD) approach in thin film form. Characterizations of α-Ce2S3 have been performed through structural, morphological and surface wettability studies. Intermixed rectangular microrods with lower contact angle provide a reduction in intrinsic resistance and effective ion diffusion path during electrochemical activities ensuring maximum utilization of the active electrode species. This leads to achieve a remarkable specific capacitance of 726 F/g at 2 mV/s scan rate with the excellent electrochemical stability of 93% at 2000 CV cycles. Efficient electrochemical findings exhibit excellent scope of α-Ce2S3 towards next-generation energy storage devices.