High-Performance Hybrid Supercapacitor with Passionfruit-Derived Cathode and Anode

Abstract

Although extensive efforts have been made to utilize raw biomass to synthesize porous carbon for supercapacitor (SC), it is difficult to achieve large-scale applications due to their 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. Ni3S2 nanoparticles encapsulated in S-doped passionfruit peel-derived porous carbon (S-PFPC) is developed as cathode material by providing sufficient space to store discharge products, S-PFPC porous channels for fast electron transport, and uniformly dispersed Ni3S2 nanoparticles for high charge storage capacity. Simultaneously, hierarchically porous carbon with a high specific surface area as anode material is also obtained by simple pyrolysis of passionfruit peel. Benefiting from the well match of 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, and it remains as high as 75 W h kg-1 even at 8710 W kg-1. More importantly, the HSC displays long-life stability with an excellent capacitance retention of 88.3% over 10000 cycles. The route for preparing biomass-derived electrode materials proposed in this work broadens a new horizon to realize high-performance SC applications.

Keywords: passionfruit peel, Ni3S2, hierarchically porous carbon, supercapacitor