Designing Na₂Zn₂TeO₆-Embedded 3D-Nanofibrous Poly(vinylidenefluoride)-co-hexafluoropropylene-Based Nanohybrid Electrolyte via Electrospinning for Durable Sodium-Ion Capacitors

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.

Cerium Selenide Nanopebble/Multiwalled Carbon Nanotube Composite Electrodes for Solid-State Symmetric Supercapacitors

“…Asymmetric supercapacitors have been studied widely because of their remarkable performances. − The basic symmetric electrochemical capacitor is made up of two similar electrodes with equivalent weight and capacitance. Furthermore, the capacitance can be represented in terms of explicit specific capacitance, which is widely accepted.…”

A heterogeneous NiCo2O4@2D-carbyne nanohybrid – a new electrode material for robust and high energy density hybrid supercapacitors

“…From the GCD curve, the specific capacitance was calculated by using the formula 22 where I indicates the current (A), Δ t indicates the discharging time (s), m denotes the mass of the electrode (mg), and Δ V indicates the potential difference (V). In the meantime, the formula used to compute the power density and energy density are as follows: 23,24 where C indicates the specific capacitance of the SC device (F g −1 ), V denotes the potential window of the SC device (V), and E Cell indicates the energy density of the cell (W h kg −1 ).…”

“…where I indicates the current (A), Dt indicates the discharging time (s), m denotes the mass of the electrode (mg), and DV indicates the potential difference (V). In the meantime, the formula used to compute the power density and energy density are as follows: 23,24 Energy density…”

Transition Metal Oxides as the Electrode Material for Sodium-Ion Capacitors

“…Sodium-based electrode materials are preferred over others due to the abundance and price advantage of sodium resources in the earth's crust. Maurya et al (2021) prepared a 3D-nanofibrous Na2Zn2TeO6 (NZTO)-implanted poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) electrolyte. AC is employed as the cathode and Na0.67Co0.7Al0.3O2 (battery-type) as an anode to create a coin cell-style SIC.…”