A flexible all-solid-state supercapacitor based on carbon-supported Ni-embedded boron nitride

It is challenging to identify alternative uses for hazardous pollutant materials that can benefit the environment. Non-biodegradable, toxic waste cigarette filters can be used as a good source of low-cost carbon for electrode materials. A new combination of Ni-embedded boron nitride (BN) with carbon derived from cigarette filters is reported as an efficient electrode for a flexible all-solid-state asymmetric supercapacitor. The incorporation of nickel nanoparticles inside BN nanosheets helps to restrict their layer stacking tendency and induce redox-active centres in 2D layers which tune their electrochemical properties. The incorporation of a conducting carbon backbone into the Ni-embedded boron nitride facilitates electron transfer pathways, thereby enhancing its electrochemical performance. The fabricated all-solid-state asymmetric supercapacitor exhibited excellent flexibility and durability for up to 250 bending cycles. The device exhibited high specific capacitance, power density, and energy density of 47 F g^-1, 4395.7 W kg^-1, and 7.9 W h kg^-1, respectively, with a volumetric energy density of 0.25 mW h cm^-3 at 2 A g^-1. The device exhibited excellent cycling stability, with 86% specific capacitance retention after 10 000 charging-discharging cycles. The real-time application of the flexible device was also tested by glowing up a red LED. The described method will pave the way for waste management solutions to produce flexible energy storage materials. This study reports such a unique combination of waste cigarette filter-derived carbon-supported Ni-embedded BN for flexible supercapacitors.