Preparation of two-dimensional sodium-boron phosphide nanosheets used for Na-ion hybrid supercapacitor devices

Abstract

The development of high-performance sodium-ion hybrid supercapacitors (NISCs) are assembled using facile bulk preparations of sodium boron phosphide (Na-BP) nanosheets as the negative electrode (battery type) and mesocarbon microbeads (MCMB) as the positive electrode (capacitor type). The Na-BP is optimized through different annealing temperatures ranging from 700 to 900 °C under an inert atmosphere. The structural and morphological characterization of the as-prepared materials were investigated by XRD, micro-laser RAMAN, FE-SEM and FE-TEM. The hybrid NISCs were assembled with an Na-BP-700//MCMB, Na-BP-800//MCMB and Na-BP-900//MCMB device configuration with a wide potential of 1–4 V vs. (Na/Na+) and their revealed a gravimetric specific capacitance (Csp) of 48.66 F/g, 83.33 F/g and 125 F/g @ 0.1 A/g, respectively. Finally, Na-BP-900//MCMB device is exhibiting excellent capacity retention of 73.52% even after 10,000 cycles at 0.3 A/g. Moreover, sodium boron phosphide (Na-BP) facile preparations by annealing method and efficient scaleable process for preparing without pre-sodiations for future hybrid supercapacitor devices.