No abstract

No abstract

No abstract

No abstract

A novel solid-state electrospun nanohybrid polymer membrane electrolyte (esHPME) for sodium-ion capacitors to improve the ionic conductivity and energy density is demonstrated. A Na2Zn2TeO6 (NZTO)-embedded 3D-nanofibrous poly­(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanohybrid electrolyte has been reported as a high-sodium-ion conducting electrolyte for sodium-ion capacitor applications. PVDF-HFP based esHPMEs with different loadings (0, 5, 10, and 15 wt %) of NZTO nanoparticles are prepared by electrospinning and further activated by soaking them in a liquid electrolyte (1M of NaPF6 in EC/DMC, 1:1 v/v) to employ as the electrolyte-separator. Among the prepared esHPMEs, the 10 wt % NZTO-embedded esHPME exhibits the maximum ionic conductivity and electrochemical window of 2.5 V. The influence of hybridization between inorganic nanoparticles (NZTO) and the organic polymer (PVDF-HFP) is investigated by physical characterization and their electrochemical performance. A coin cell-type Na-ion supercapacitor is fabricated using battery-type Na0.67Co0.7Al0.3O2 as the anode and activated carbon as the cathode. The fabricated Na-ion supercapacitor [Na0.67Co0.7Al0.3O2/esHPME (10 wt % NZTO)/AC] delivered an energy density of 99.375 F g–1 at 1 A g–1 current density and exhibits 84% of capacity retention up to 1000 cycles of charge discharging. The Na-ion capacitor showed a maximum energy density and power density of 35.33 W h kg–1 and 1.6 kW kg–1, respectively. Thus, the present work demonstrates the great potential of the electrospun PVDF-HFP/NZTO-based nanohybrid membrane electrolyte for durable Na-ion capacitors.

No abstract

Herein, we prepared all-solid-state electrospun poly­(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/Li7.1La3Ba0.05Zr1.95O12 nanohybrid membrane electrolytes (esHPMEs) by an electrospinning technique for high-energy Li-ion capacitors (LIC). As developed, an esHPME possesses superior thermal stability (150 °C) with improved separator characteristics like porosity and electrolyte uptake. Synergistic coupling between highly active garnet nanoparticles (Li7.1La3Ba0.05Zr1.95O12) and a PVDF-HFP polymer has been confirmed by X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared analysis. The morphological feature of an esHPME was confirmed by field emission scanning electron microscopy analysis. Interactions between Li-ion conductive garnet nanoparticles and the host PVDF-HFP polymer (esHPME with 10 wt % Li7.1La3Ba0.05Zr1.95O12 (LLBZO)) lead to an improved ionic conductivity of 3.30 × 10–3 S cm–1 at 25 °C with a working potential of 4.6 V compared to a pure PVDF-HFP membrane. LIC (LiCoO2/esHPME (10 wt % LLBZO)/activated carbon) exhibits a superior specific capacitance of 123 F g–1 at a current density of 1 A g–1 with a capacity retention of 83% even after 1000 cycles. LIC assembled with 10 wt % LLBZO/PVDF-HFP nanohybrid membrane electrolyte exhibited a maximum energy and power density of 43.77 W h kg–1 and 7.973 kW kg–1, respectively. This work demonstrated the opportunities of all-solid-state Li-ion capacitor development using electrospun nanohybrid polymer membrane electrolytes that exploit the synergistic play between inorganic–organic entities.

Recent advance in nanotechnology leads to develop a variety of metal chalcogenide quantum dots (QDs) such as binary metal chalcogenides QDs and alloyed QDs. The average diameter of the QDs lies in the range of 2 to 10 nm which contains almost 10 to 1000 atoms. Due to the quantum confinement effect, size-dependent photoemission characteristics, photo-optical and photovoltaic properties, QDs have a wide variety of applications. It has attracted more attention in light-emitting diodes, medicines, quantum computers and energy devices. As an important part of quantum dot sensitized solar cells (QDSCs), QDs play an eminent role to improve photoconversion efficiency (PCE). This review article mainly focuses on the influence of metal chalcogenides QDs on the photovoltaic performance of liquid junction QDSCs, including parts and working principle of QDSC, photovoltaic parameters of QDSC, types of metal chalcogenide QDs, synthesis methods of metal chalcogenide QDs, optoelectronic properties of metal chalcogenide QDs, efficient deposition method of metal chalcogenide QDs sensitizer and its photovoltaic performance. We finally made conclusions and suggestions for future research to improve the PCE. This article will give more information about the variety of QDs and it is helpful to the researchers for making efficient QDSCs.