Na-ion conducting filler embedded 3D-electrospun nanofibrous hybrid solid polymer membrane electrolyte for high-performance Na-ion capacitor

Synergistic coupling of polymer with highly Na+ conducting ceramics is an effective approach to alleviate the poor thermal stability and low ionic conductivity challenges of an electrolyte. Herein, we have reported a rational design of Na2Zn1.97Ca0.03TeO6 (NZCTO) nanofillers-reinforced poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP)-based 3D-electrospun nanofibrous hybrid polymer membrane (ESHPM) as a separator cum electrolyte obtained by an electrospinning technique. Physico-chemical properties of NZCTO and ESHPMs were characterized for its morphology, porosity and electrolyte uptake measurement, crystallinity, thermal stability, dimensional stability, operating potential window, and ionic conductivity. ESHPME immobilizing a liquid electrolyte solution [1 M of sodium hexafluorophosphate (NaPF6)] in ethylene carbonate (EC)/dimethyl carbonate (DMC), 1/1v/v) exhibited an excellent ionic conductivity (sigma(RT) ? 1.47 x 10(-3) S cm(-1)). A Na-ion capacitor (NIC) comprising high-capacity NaCo0.7Al0.3O2 (NCAO) and rapid ion-absorbing activated carbon (AC)-based electrodes with ESHPM (10 wt.% NZCTO) electrolyte delivers the specific capacitance of 103.57 Fg(-1) at the current density of 1 Ag-1. This NIC retains 89% of its initial capacitance up to 1000 charge-discharge cycles. Furthermore, NIC demonstrated a maximum energy and power density of ? 36.82 W h kg(-1) and ? 5.71 kW kg(-1), respectively. This research promises to develop high-performing NICs with high energy and power densities.