Binder-free phosphor-coated multiphase bismuth cobalt-selenide electrode for solar-charged quasi-solid-state hybrid supercapacitors

Abstract

The enormous utilization of fossil fuels and the accelerated progression of global warming have irreversible destructive consequences on Earth's biodiversity. In response to this concern, there is a growing need to adopt green and renewable energy sources as effective strategies for mitigating environmental challenges. Herein, we report the novel synthesis and electrochemical properties of a binder-free phosphorus-coated multiphase bismuth-cobalt selenide/nickel foam (P@BCS/NF) electrode. Phosphorization was performed under an N2 atmosphere in a tube furnace to cover the electrodes. The synthesized electrode exhibited a porous nanorod morphology, which enhanced its electrochemical and energy storage properties. The P@BCS/NF electrode delivered a high areal capacity value of 836.4 µAh cm−2 in 1 M KOH electrolytic solution with excellent cycling stability, 81.4 % capacity retention, and 98.8 % coulombic efficiency over 10,000 cycles. A quasi-solid-state hybrid supercapacitor (QHSC) device was constructed using P@BCS/NF as the positive electrode and activated carbon as the negative electrode. The QHSC device showed maximum areal energy and power density values of 384.37 μWh cm−2 and 21750 μW cm−2, respectively, together with high stability of 94.4 % capacitance retention after 10,000 cycles. The practical application of the QHSC device was demonstrated in a PVA-KOH electrolytic environment by powering various electronic devices.