Perovskite rare earth porous hollow microspheres of SmFeO3/MWCNT battery type asymmetric hybrid supercapacitors

The rapid advancements made by science and technology in the present world are astonishing and have a way of stimulating our imagination. Modern research centres on search for unique cathode electrodes to improve energy density in hybrid supercapacitors (HSCs). A battery-type perovskite rare earth-based SmFeO3/MWCNT electrode is being investigated as cathode electrode for future-generation energy storage devices. Herein, perovskite rare earth-based metal oxides and its carbon composites (SmFeO3, SmFeO3/GC,SmFeO3/MWCNT) are flourishingly synthesized via one-step solvothermal technique as cathode materials for hybrid supercapacitors. The asymmetric solid-state supercapacitor SmFeO3/MWCNT//CNT device is constructed with an excellent 216.68 F/g specific capacitance, 67.71 Wh/kg energy and 749.97 W/kg power density at 1 A/g current density. An improved cycling performance of 79.83% capacity retention and 99.84% coulombic efficiency after 20000 long-cycles is reported. This work revealed that SmFeO3/MWCNT//CNT AHSSCs offer boundless ability as good electrode for practical energy storage applications.This work was supported by MHRD RUSA–Phase 2, UGC-SAP, DST-FIST, and PURSE grants

SmNiO₃/SWCNT perovskite composite for hybrid supercapacitor

Modern world has an unparalleled focus on science and technology as an energy storage device as a promising alternative sources to tackle the growing energy crisis and play an important role in economic development. Thus, new approaches and novel promising electrode materials are trying to overcome high energy density without reducing supercapacitors power density and a long lifetime stability. Accordingly, rational flower like structural control of rare earth nickelate-based composite electrodes is also important but very challenging. The role of carbon composites such as single walled carbon nanotube (SWCNT) and multi walled carbon nanotube (MWCNT) with samarium nickelate (SmNiO3) is studied. Herein, the perovskite rare earth SmNiO3, SmNiO3/MWCNT and SmNiO3/SWCNT composites are prepared as potential electrode materials by solvothermal method and never reported before as electrode for supercapacitors. An asymmetric hybrid supercapacitor (SmNiO3/SWCNT//CNT) was fabricated and presented specific capacitance, energy and power density of 170.58 F/g, 53.30 Wh/kg and 749.88 W/kg at 1 A/g. The assembled asymmetric hybrid device exhibited 79.34 % of capacitance retention and 97.52 % of coulombic efficiency even after the continuous 20,000 long cycles. These superior electrochemical properties make the hybrid microflower rare earth nickelate as a good candidate for next generation electrodes in hybrid supercapacitors.This work was supported by MHRD, RUSA–Phase 2, UGC-SAP, DSTFIST, and PURSE grants

Unique hierarchical mesoporous SmMnO3/MWCNT for highly efficient energy storage applications

Unique hierarchical mesoporous with hollow nanostructures of rare earth transition metal oxides (RE-TMOs) has obtained significant research notice owing to its surface permeability (hollow interior), bulky surface area, low density, as electrode materials for better search of supercapacitors. Nevertheless, controlling the hallow nanostructures in a simple method is a very challenging one. A unique SmMnO3/MWCNT material as a potential battery-typesupercapacitor electrode material was prepared from a solvothermal method in water/ethanol media. The as prepared SmMnO3/MWCNT electrode delivered 47.13 mAh/g@1A/g specific capacities from the galvanostatic charge discharge (GCD) analysis and delivered 86.22% capacity retention over 5000 cycles. Furthermore, an assembled hybrid supercapacitor (SmMnO3/MWCNT//CNT HSC) displays 255.82 F/g specific capacitance, 79.94 Wh/Kg @ 1 A/g energy density, 14996.39 W/Kg@20 A/g power densities with the decent cycling stability of 79.83% and coulombic efficiency of 99.84%@20000 cycles.This work was supported by MHRD RUSA–Phase 2, UGC-SAP, DST-FIST, and PURSE grants

Quaternary Cu2FeSnS4/PVP/rGO Composite for Supercapacitor Applications

Electrochemical energy storage is a current research area to address energy challenges of the modern world. The Cu2FeSnS4/PVP/rGO-decorated nanocomposite using PVP as the surface ligand was explored in a simple one-step solvothermal route, for studying their electrochemical behavior by designing asymmetric hybrid supercapacitor devices. The full cell three-electrode arrangements delivered 748 C/g (62.36 mA h/g) at 5 mV/s employing CV and 328 F/g (45.55 mA h/g) at 0.5 A/g employing GCD for the Cu2FeSnS4/PVP/rGO electrode. The half-cell two-electrode device can endow with 73 W h/kg and 749 W/kg at 1 A/g energy and power density. Furthermore, two Cu2FeSnS4/PVP/rGO//AC asymmetric devices connected in series for illuminating a commercial red LED more than 1 min were explored. This work focuses the potential use of transition-metal chalcogenide composite and introduces a new material for designing high-performance supercapacitor applications

Marigold flower like structured Cu2NiSnS4 electrode for high energy asymmetric solid state supercapacitors

The growth in energy devices and the role of supercapacitors are increasingly important in today’s world. Designing an electrode material for supercapacitors using metals that have high performance, superior structure, are eco-friendly, inexpensive and highly abundant is essentially required for commercialization. In this point of view, quaternary chalcogenide Cu2NiSnS4 with fascinating marigold flower like microstructured electrodes are synthesized using different concentrations of citric acid (0, 0.05 M, 0.1 M and 0.2 M) by employing solvothermal method. The electrode materials physicochemical characteristics are deliberated in detail using the basic characterization techniques. The electrochemical studies revealed better electrochemical performances, in particular, [email protected] M-CA electrode revealed high 1029 F/g specific capacitance at 0.5 A/g current density. Further, it retained 78.65% capacity over 5000 cycles. To prove the practical applicability, a full-cell asymmetric solid-state device is fabricated, and it delivered 41.25 Wh/Kg and 750 Wh/Kg energy and power density at 0.5 A/g. The optimum citric acid added Cu2NiSnS4 electrode is shown to be a promising candidate for supercapacitor applications

Electrochemical energy storage and conversion applications of CoSn(OH)₆ materials

Supercapacitors are a boon in today's modern world. The role of a supercapacitor is important in providing electrical energy in the most efficient way for the usefulness of the society. Herein, co-precipitation technique was adapted to prepare electrodes for energy storage and water-splitting purposes. Role of ammonia at different concentrations was deliberated. Better 269 and 364 F/g capacitance was attained for best electrode from cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) curves, respectively. The capacitive and diffusion contribution of all electrodes were estimated and found to be 91.88 and 8.12 for the best sample. A better diffusion contribution of the higher-concentration ammonia sample revealed a higher specific capacitance. In this study, 91.33% capacitive retention and 90.38% columbic efficiency were calculated after 5000 cycles of charge and discharge. Further electrochemical method like linear sweep voltammetry (LSV) and chronoamperometry (CA) was explored for water-splitting applications and 367 mA/g current density with 264 mV overpotential was achieved in the LSV plot. CA test was carried out for 10 h to reveal 189 mA/g current density and delivered 74% stability. Therefore, the present study describes different technique to extend electrochemical supercapacitor and water-splitting purposes.This work was supported by UGC-SAP, DST-FIST, DST-PURSE, MHRD-RUSA grants

Morphology investigation on direct growth ultra-long CNTs by chemical vapour deposition method for high performance HER applications

Carbon nanotube (CNT) is prepared by chemical vapor deposition method and their electrochemical behaviors for instance oxygen evolution (OER) and hydrogen evolution (HER) reaction have been successfully studied. In recent times, Pt-free electrocatalysts have been greatly attractive in electrochemical hydrogen evolution reactions for the replacement of fossil fuels and development of sustainable energy carriers. Chemical vapor deposition method was used as an efficient way to synthesize CNTs directly. The as prepared free-standing and multifunctional CNT electrodes are used for overall water splitting applications. In this work, we have designed CNT as electrode material as well as current collector using Ni-foil and Ni-foam substrate and their fundamental characterizations confirm the structural, morphological behaviors of CNTs. Moreover, the well-ordered growth of CNT was obtained in Ni-foam CNTs 1 and 2, whereas in the Ni foil CNTs 1 and 2 less growth of CNT and amorphous carbon sponge was exceeded, which was further confirmed by the SEM images. The achieved electrochemical HER results displayed that the Ni-foam-CNT-2 exhibited lower overpotential, smallest Tafel slope and lower resistance value of 110 mV, 240 mV/dec and 0.24 Ω respectively. Moreover, Ni-foam-CNT-2 revealed excellent stability with 86.6 % retention over 20 h. Hence, it is one of the cost-effective and reliable materials for electrochemical hydrogen evolution reaction.This work was supported by UGC-SAP, DST-FIST, DST-PURSE, MHRD-RUSA grants

Energy storage applications of CdMoO₄ microspheres

In this study, a one-step hydrothermal method was used to synthesize cadmium molybdenum oxide and revealed cationic cetyltrimethylammonium bromide surfactant effects on material preparation and energy storage characteristics. X-ray diffraction confirmed tetragonal-phase CdMoO4. Symmetric stretching modes of molybdenum oxide were confirmed from a Raman spectrum. A Fourier-transform infrared spectrum confirmed the presence of functional groups. Scanning electron microscopy images revealed a bunch of hierarchical microspheres of about 100–200 nm diameter. The specific capacitance achieved for CdMoO4, 0.1 M CTAB + CdMoO4, and 0.2 M CTAB + CdMoO4 were 200 F/g, 310 F/g, and 382 F/g, respectively, at 0.5 A/g. In addition, long-term cyclic stability for the best performing electrode (0.2 M CTAB + CdMoO4) material was investigated to explore cyclic performances of the supercapacitor. During the experiment, 86.01% capacity was retained after 5000 cycles at 5 A/g. The product activity is promising for high-efficiency supercapacitors due to the ease of production, environmentally friendly nature, and low cost of the synthesized material.This work was supported by RUSA, UGC-SAP, DST-FIST, DST-PURSE grants. The authors extend their appreciation to the Researchers supporting project number (RSP-2020/247) King Saud University, Riyadh, Saudi Arabia

Heterostructured SmCoO₃/rGO composite for high-energy hybrid supercapacitors

A supercapacitor is an efficient energy storage system that acts as an excellent booster to deliver high power density required for batteries and fuel cells. Recently, composite material–based supercapacitors have attracted much more interest as promising greener and more capable candidates in energy-saving use. In this work, samarium cobalt oxide–decorated reduced graphene oxide (SmCoO₃/rGO) was prepared employing solvothermal route and used as reliable electrode material. The maximum specific capacity achieved was 30.80 mAh/g for 1 A/g of SmCoO₃/rGO nanocomposite with capacity retention of 86.95%@5A/g over 5000 charge discharge cycles. Better electrochemical performance of samarium and reduced graphene oxide nanostructures prevent the transfer of electrons through electrochemical active sites, creating electronic and structural diversity of electro active material. In addition, SmCoO₃/rGO/AC hybrid supercapacitor device that delivered good energy and power density of 52 W h/kg and 752 W/kg at 1 A/g was designed. 74.28% capacitive retention and 98.26% coulombic efficiency was maintained over 15,000 cycles.This work was supported by RUSA, UGC-SAP, DST-FIST, DST-PURSE grants. The authors extend their appreciation to the Researchers supporting project number (RSP-2020/247) King Saud University, Riyadh, Saudi Arabia