Ni3S2 nanoparticles encapsulated in S-doped biomass-derived hierarchically porous carbon as an advanced electrode for excellent hybrid supercapacitors performance

Although extensive efforts have been made to utilize raw biomass to synthesize porous carbon for the super-capacitor (SC), its large-scale application is difficult to achieve due to its slow diffusion kinetics and insufficient storage sites. Herein, biomass-derived high-capacity/high-rate cathode and anode materials are designed to realize high-performance SC. S-doped passionfruit peel-derived porous carbon (S-PFPC) is used as support to anchor nickel sulfide (Ni3S2) nanoparticles and is developed as cathode material. It provides sufficient sites to store discharge products, S-PFPC porous channels for fast electron transport, and uniformly dispersed Ni3S2 nanoparticles for enhance charge storage capacity. Simultaneously, hierarchically porous carbon with a high specific surface area as the anode material is also obtained by simple pyrolysis of passionfruit peel. Benefiting from the well-matched anode and cathode structures, the assembled Ni3S2 @S-PFPC//PFPC hybrid super-capacitor (HSC) exhibits a high energy density of 118 W h kg-1 at a power density of 433 W kg-1. In addition, it exhibits long-life stability with excellent capacitance retention of 88.3% over 10000 cycles. The route for pre-paring biomass-derived electrode materials proposed in this work broadens the horizon to realize high-performance SC applications.