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Rare earth metal oxides have been widely used as pseudocapacitor electrodes owing to their unique physical and electronic properties. The present paper reports the synthesis and pseudocapacitor applications of praseodymium oxides, owing to their unique physical properties. PrOx/unzipped carbonnanotubes were synthesized following a hydrothermal approach. Detailed morphological as well as electrochemical analyses were performed to elucidate how the unique properties of PrOx affect the charge storage ability. Special emphasis was given on the effect of anion intercalation due to the surface oxygen vacancies in PrOx which would contribute towards the pseudocapacitive energy storage. Oxygen intercalation was exploited for the first time in fluorite crystals for fast energy storage and a specific capacitance value as high as 1099 F/g was obtained with the electrodes. An asymmetric supercapacitor prototype was also fabricated with a V2O5/graphene counter electrode and the energy and power density values obtained are as high as 52.08 Wh/kg and 2.9 kW/kg, respectively.

The report provides a preliminary assessment of the charge storage prerogatives of MoS2-Graphene composite electrodes interfaced with a novel formulation of aqueous electrolyte. The aqueous alkaline electrolyte based on KOH consisted of ferromagnetic nanoparticle additives. This has been demonstrated to be a feasible approach for developing pseudocapacitor electrodes of high specific capacitance and rate capability. The electrodes exhibited a specific capacitance as high as 1556 Fg−1 as calculated from Cyclic Voltammetry curves with a cyclic stability of ∼94% at the end of 5000 charge–discharge cycles. This approach can be extended to different electrochemical systems based on electrode architecture as well as active materials. Moreover, various structural modifications like core/shell ferromagnetic nanoparticles can be used to improve the performance of selected electrode materials.

Supercapacitor electrodes assembled from meso/macroporous camphor-derived carbon sponges show highly promising performance in ac line-filtering. The coin-type supercapacitor exhibits an ultrafast frequency response with a phase angle of −78° and a RC time constant of 319 μs at 120 Hz and may be a viable alternative to the presently dominant aluminium electrolytic capacitors.

This study demonstrates a novel approach by which amorphous nickel molybdate nanoflakes were processed into high surface area electrodes for supercapacitors. Time dependent studies showed evolution of flake-like morphology from anisotropic nuclei particles exhibiting high redox activity. An intrinsic correlation between the surface area, specific capacitance and the internal resistance has been deduced and explained on the basis of relative contributions from the faradic reactions of NiMoO 4 . Relative contributions from the bulk and surface processes were mathematically modeled. The electrodes exhibited specific mass capacitance values as high as 1650 F g −1 which is the highest reported value so far. Coin cells employing these rechargeable electrodes were also demonstrated exhibiting an energy and power density of 92 W h kg −1 and 23 kW kg −1 , respectively, with excellent cyclic stability.

The present paper reports the application of a rare earth metal oxide – titania nano tube (TNT) composite for supercapacitor applications. Highly ordered arrays of single walled titaniananotubes of length approximately 4 μm were synthesised on titanium metal foil via a modified single step electrochemical anodization method. Nanostructured ceria is deposited on as prepared TNT by simply impregnating in cerous nitrate solution, followed by heat treatment. The characterizations were done by XRD and FE-SEM analysis. Supercapacitive performance is monitored using techniques such as CV, GCD and EIS. The pristine TNT itself shows promising supercapacitive performance (specific capacitance values ~ 6.82 mF/cm2), which is enhanced significantly by coating psuedocapacitive ceria. Among different ceria deposited samples, 0.075 Ce showed the best results with specific capacitance values ~55.28 mF/cm2 at scan rate 5 mV/s, owing to its open porous nanotubular morphology (optimal tube diameter around 20 nm) facilitating smooth charge transport and exposure of enormous amount of active material to the electrolyte, marking an enhancement of about 710% as compared to pristine TNT supercapacitors.

Camphoric carbon wrapped NiS powders have been profitably exploited to fabricate high surface area electrodes for Li storage. The NiS morphology showed a network of interconnected nanoscale units with rod like profiles which terminated into needle-like apexes spanning diameters of about 50–80 nm. These particles were pyrolyzed using a camphoric solution to form a carbon sheath wrapping. These carbon functionalized NiS powders were processed into high-surface-area cathodes for a fully functional coin cell unit. A detailed study was performed to elucidate the effect of carbon content on the performance of these coin cells. BET surface area analysis revealed that these carbon sheathed NiS could exhibit a high surface area of 32 m2 g−1 compared to pristine powders which exhibited surface area values of 20 m2 g−1. From the analysis of relevant electrochemical parameters, an intrinsic correlation between the specific capacity, internal resistance and temperature has been deduced. Relative contributions of capacitive and diffusion-controlled processes underlying these thin-film electrodes have been mathematically modeled. These thin-film electrodes exhibited specific capacity values as high as 500 mA h g−1 as determined from charge discharge curves. The present study shows that this functional material can provide the advantages of simple processing technique, low cost, and scalability.

Nanowires of NiO were successfully synthesized using a simple hydrothermal route. The nanowires were characterized for phase composition and morphology by X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques, respectively. XRD analysis showed that the powders produced were of high purity cubic NiO phase. Selected area electron diffraction (SAED) analysis during TEM showed the growth direction of NiO nanowires in (1 0 0), while exhibiting an average diameter of ∼ 65 nm. BET analysis showed these nanowires exhibiting a surface area of 153.2 m2/g. These nanowires were electrophoretically deposited on titanium foils as thin layer (∼5 μm thickness) and were studied for their capacitive behavior as electrodes for supercapacitor applications. Image analysis and atomic force microscopy (AFM) studies revealed the thin film coating to be highly porous (>50%). Cyclic voltammetry (CV) studies on these electrodes exhibited a specific mass capacitance of 750 F/g with 12% capacitance fade at the end of 1000 cycles. The present study elucidates how NiO surface morphology and OH− adsorption/desorption behaviors underlying these electrodes impact the chemical and structural stability performance.

The report provides a preliminary assessment of the charge storage prerogatives of an asymmetric electrochemical capacitor employing a carbon-grafted NiO electrode interfaced with 1-ethyl-3-methyl imidazoliumdicyanamide as an ionic liquid electrolyte. This configuration has been demonstrated to be potentially exploited for developing hybrid supercapacitors providing as high energy density as 21 W h Kg(-1).

The present study provides the first report on the preparation and utilization of camphoric carbon nanobeads grafted onto Ni/NiO nanowires for rechargeable electrodes for energy-storage applications. These functionally graded nanowires were electrophoretically deposited onto nickel foils and processed into high-surface-area electrodes. A detailed study has been performed to elucidate the effect of carbon content, different electrolytes, and their concentrations on these nanowires. BET surface area analysis revealed that these grafted nanowires could exhibit a high surface area of about 106 m

The present study demonstrates a novel approach by which titanium foils coated with electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT) in combination with sputtered platinum can be processed into a high-surface area cathodes for dye-sensitized solar cells (DSSCs). A detailed study has been performed to elucidate how surface nanomorphology and I(-)/I(3-) redox reaction behaviors underlying these photocathodes impact the DSSC performances. From the analysis of the relevant electrochemical parameters, an intrinsic correlation between the photovoltaic performances and the cathode surface area has been deduced for such a system and explained on the basis of relative contributions of the galvanic coupling properties of the nanomorphology PEDOT film and platinum. Depending on the type of photocathodes incorporated, it was observed that these PEDOT coated cathodes can exhibit higher stability over a given time range and photo-conversion efficiencies 12-40%, higher than that achievable in absence of the intermediate PEDOT coatings. It has been shown that DSSCs based on such metal-polymer hybrid photo-cathodes allow significant room for improvement in the catalytic performance at the electrode/electrolyte interface.