Synergistic Manipulation of Micro-Phosphorus and Sulphur Incorporation on Carbonaceous Cathode Endows Superior Zinc-Ion Storage Performance

Abstract

Aqueous zinc-ion hybrid capacitors (ZHCs) stand out as emerging electrochemical energy storage systems, combining the merits of low cost and impressive theoretical capacity. Nevertheless, unsatisfactory energy density and cycle life of ZHCs limit their widespread application. Herein, a simple one-pot approach was introduced to mitigate the issues through phosphorus and sulfur synergistically activated carbon nanosheets with hierarchically porous architecture (PS-HPCNS), deemed as a potential cathode candidate. The PS-HPCNS can show an excellent Zn-ion storage performance, including a high electrochemical capacity of 240.1 mAh g-1 under 0.2 A g-1, a decent energy density of 139.3 Wh kg-1 at 116 W kg-1, also a long cycle life over 50000 cycles with 84.6% capacity retention. Theoretical simulations combined with experimental analysis indicate that P and S dual-doping can enhance pseudocapacitance, significantly boost the interaction with Zn2+ ions and improve reaction kinetics. This work offers an appealing route to construct carbon cathode with superior zinc-ion storage ability and gives significant guidance towards advancing energy storage technologies.