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 supercapacitor (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 supercapacitor (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 preparing biomass-derived electrode materials proposed in this work broadens the horizon to realize high-performance SC applications.