Homologous Hierarchical Porous Hollow Carbon Spheres Anode and Bowls Cathode Enabling High-Energy Sodium-Ion Hybrid Capacitors

Abstract

It is a highly expected avenue to construct dual-carbon sodium-ion hybrid capacitors (SIHCs) using hierarchical porous carbon with interconnected pores, high accessible surface area, and disordered carbon frameworks for ameliorating the sluggish kinetics of SIHCs. In this work, a novel dual-carbon SIHCs system with homologous enhanced kinetics hierarchical porous hollow carbon spheres (HPCS) and hierarchical porous hollow carbon bowls (HPCB) as the anode and cathode is constructed for the first time. In a Na half-cell configuration, the HPCS anode synthesized through a facile one-pot in-situ template route demonstrates a superior reversible capacity as well as outstanding rate capability and cycleability, and the HPCB cathode fabricated by chemical activation of HPCS exhibits excellent capacitive behaviors. Thanks to superior properties and structures of the anode and cathode, the constructed novel dual-carbon SIHCs present an exceptionally high energy/power density (128.5 Wh kg-1 and 11.9 kW kg-1), along with a long cycling lifespan with retained morphology. This study on the kinetics of enhanced dual-carbon SIHCs opens a new avenue for optimizing the microstructure of hierarchical porous carbon and constructing new type of high-performance SIHCs systems.