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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.

Metal sulphides have recently been explored as a very promising pseudocapacitor electrode, owing to their unique physical, electronic and electrochemical properties. This study reports the synthesis and pseudocapacitor applications of 2D cadmium sulphide (CdS) nanosheets deposited on Ni foam via electrophoretic deposition method. Comprehensive morphological and electrochemical analyses were performed to elucidate the correlation between the structural features of CdS and their charge storage properties. The single electrode characterizations of CdS could exhibit a specific capacitance as high as 1165 F g–1 at 2 mV s–1. An asymmetric supercapacitor prototype was also fabricated using the CdS nanosheets with ceria–titania nanotube composite (CeO2–TNT) counter electrode. The device could exhibit an energy density as high as 14.58 Wh kg–1 at a power density of 1.9 kW kg–1. At the end of 2000 cycles, the device could retain 100% of its initial capacitance.

Nanoelectronics has earned prominent importance in smart manufacturing, which is considered to be the backbone of Industry 4.0. With the advent of smart and novel technologies, together with digital advancements, the missions and visions of smart industry can be pursued enthusiastically. Automation and control technologies in smart manufacturing systems require highly selective, cost-effective, and flexible nanosensor devices. Consequently, there is an extreme demand for novel materials and techniques for sensor counterparts. This chapter highlights the substantial contribution of nanomaterials in the present and future development of flexible nanosensors. A variety of substrate materials with distinct mechanical and chemical properties are discussed in detail. The involvement of highly promising nanomaterials such as metals, conductive polymers, and carbon-based materials in the fabrication of sensor electrodes are also explored extensively. The comprehensive investigation of design, fabrication, authenticity, simulation, and major applications of the flexible systems open up many possibilities for future development.

One of the most interesting implementations of nanotechnology is the development of nanobiosensors. Nanobiosensors can be of various types, based on the components and the working principle, including optical, electrochemical, and electromechanical. Nanobiosensors are being widely used for the diagnosis of diseases at an early level. Compared to conventional techniques, nanobiosensors offer significant advantages, such as rapid sensitivity and selectivity, shorter response time, biocompatibility, and easy miniaturization of devices. This chapter summarizes the advances in disease diagnosis, with special emphasis on glucose level detection using nanobiosensors. The application of DNA-based nanobiosensors, capsule endoscopy, conducting polymer-based nanobiosensors, and smart packaging using nanobiosensors in the food industry are discussed in detail. The production of deliverables using smart biosensor technology will definitely improve our quality of life.

A novel anode design is demonstrated with Si nanostructures with double-layered protection for an aqueous rechargeable Li-ion Battery (ARLIB). Si nanoparticle-embedded LATP (lithium aluminum titanium phosphate; Li1.3Al0.3Ti1.7(PO4)3), as well as LATP-PVDF polymer nanocomposites, is used as the protective layers. The unique anode structure is expected to be useful in overcoming the cathodic challenges and subsequent gas evolution reactions, thus widening the operating voltage of an ARLIB up to 3.5 V. The layered anodes exhibited discharge capacities of 2630 mAh g−1 at 0.1 C as half cells in 2 M Li2SO4 aqueous solution as the electrolyte. They are also coupled with LiFePO4 cathode, and the full cells demonstrate a discharge capacity of 123 mAh g−1 with the calculated energy density values of 138 Wh kg−1 which is comparable with the conventional organic electrolyte-based LIBs. They can cycle 500 times with capacity retention of more than 75%. Hence, the conclusions from the present study project a promising anode design for ARLIBs, with high capacities and long cycling stabilities.

The present study demonstrates a novel approach by which porous brick like nanostructures of nickel oxide can be prepared following a combustion assisted rout. The as synthesized NiO active material is electrophoretically deposited on porous Ni foils and processed into high-surface area thin film electrodes for supercapacitor applications. A detailed study has been performed to elucidate how surface nanomorphology and porosity can impact the pseudocapacitive performances of NiO electrode. From the analysis of the relevant electrochemical parameters, an intrinsic correlation between the electrode performances and these parameters have been deduced and explained. According to single electrode studies the electrodes exhibited a specific capacitance value as high as 1058 F/g at 5 mV/s with good cyclic stability.

There is an ever-increasing demand for the improvements in rechargeable Lithium secondary batteries owing to their high energy density, flexibility, cyclic stability and wide range of applications. Even though the science is often criticized for its slow progression, countless variations on the basic lithium chemistry are been investigated to address the safety and performance issues. The major components raising safety concerns are the volatile organic electrolytes and the dendrite forming Li metal electrodes. The present review covers the application of ionic liquid electrolytes in combination with the alloy anodes wherein these relatively advance Li ion battery components mutually benefits to overcome the existing issues related to cell efficiency as well as safety concerns. The essential understanding of lithiation/delithiation process as well as the SEI layer formation of alloy anodes in combination with Room temperature IL electrolytes is considered as an approach towards safer Li batteries.

In this work, we report the synthesis of titania nanotube (TNT) -VO2(M) nanocomposites through a combined potentiostatic anodisation-hydrothermal procedure and its application in supercapacitors. Structural, morphological and chemical characterisations were done by XRD, FE-SEM and XPS analyses and electrochemical characterisations were done by CV, GCD and EIS. The TNT-VO2(M) nanocomposites exhibited very high capacitive performance as compared to their individual components, due to the synergistic contribution from both. Altered morphologies for composites were obtained at varying hydrothermal temperatures under similar conditions. The TNT-VO2(M) nanocomposite which is formed at 180 °C, TNT-V180 with VO2(M) nanorings over TNT showed the best CV performance in three electrode configuration with specific capacitance values ~152.21 mFcm−2 at scan rate 5 mVs−1 and confirmed by GCD and EIS. The open porous morphology with maximum available surface aided more charge accumulation at the electrode-electrolyte interface and better redox interaction with electrolyte ions resulting in its unique synergistic capacitive behaviour compared to others. The asymmetric supercapacitor fabricated with TNT-V180 as the negative electrode and active carbon (AC) as the positive electrode delivered a very high specific capacitance of 246.67 mFcm−2 with an ultra-high energy density of 111 μWhcm−2 at 180 μWcm−2 power density.

In the present work, we demonstrate the supercapacitor applications of titania nanotube @ α -Fe2O3 composites (TNT@ α -Fe2O3) synthesized via successive anodization–hydrothermal methods. The structure and morphology of the composites were studied through XRD and SEM analyses and the electrochemical properties were studied through CV, GCD and EIS analyses. The hybrid composite, TNT-Fe4 exhibited highest supercapacitor performance with a capacitance of 157.32 mFcm−2 at a scan rate of 5 mVs−1 owing to the unique micro/nano hybrid architecture of the composite, comprising of a hierarchical layered Fe2O3 coating on titania nanotubes. The asymmetric supercapacitor fabricated with the composite electrode together with activated carbon showed an excellent capacitance of 142.86 mFcm−2 with an energy density of 38. 88 μ W hcm−2 at 0.2 mAcm−2. The high rate capability and outstanding cyclic stability of the composite validate the potential application of the device in charge-storage systems.

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 study reports the synthesis of NiO hexagons with exposed {110} facets on metallic Ni backbones. Intrinsic correlations were deduced between the surface area, crystalline anisotropy and the electrochemical performance. These metal backboned hexagons were employed as supercapacitor electrodes exhibiting specific mass capacitance value as high as 2100 Fg −1 . Further, a working model button cell employing these rechargeable electrodes is also demonstrated exhibiting an energy and power density of 17 Wh kg −1 and 3.5 kW kg −1 , respectively.

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 present study reports the electrospinning of commercially available polyaniline-carbon black composite to develop conductive nanofibrous mats using polyvinyl alcohol as a binder solution. This binder solution was sublimated at 230 � C to attain a complete conducting nanofiber network. The binder sublimation was confirmed using thermo gravimetric analysis (TGA). Ultra-violet visible spectroscopy was used to determine the refractive index values for porosity measurements. It was observed that the heat treatment reduced the fiber diameter from ∼ 250 nm to ∼ 160 nm and increased the porosity from 41 ± 1.2% to 70 ± 2%. The spatial specific conductance mapping using Scanning Electro-Chemical Microscopy showed that the presence of polyvinyl alcohol binder in polyaniline-carbon black composite could introduce percolation threshold. The heat-treated fibers showed four times increase in specific conductance values on removal of binder phase from the fiber structure. The role of nanoscaled Schottky barriers in determining conductive pathways through polymer by hopping mechanism and also along carbon black particles are also been proposed in this study.

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.