Three-dimensional nitrogen-doped dual carbon network anode enabling high-performance sodium-ion hybrid capacitors

Abstract

It is urgent for sodium-ion hybrid capacitors (SIHCs) to exploit a porous carbon anode that integrates high reversible specific capacity, rapid kinetics and superb cyclability. Herein, a three-dimensional dumpling-like glyururil-derived porous carbon@RGO composite (GLCG) constructed from nitrogen-doped (10.29 at.%) hierarchical porous carbon filling and highly conductive flexible RGO wrapper is synthesized. As for the Na half-cell, GLCG anode delivers high reversible specific capacity (282 mAhg-1 at 0.05 Ag−1) as well as superb rate capability (122.8 mAhg-1 at 10 Ag−1) and lifespan (3000 cycles at 2 Ag−1). Moreover, the origin of the excellent sodium-ion storage properties of GLCG is revealed by in-depth mechanism analysis. Consequently, a SIHCs with GLCG anode is constructed, which displays high energy density of 108 Wh kg−1, high power density of 14.2 kW kg−1 and long lifespan of 66% capacity retention after 5000 cycles at 2 Ag−1. This work provides an alternative avenue for the exploitation of high-performance carbon-based SIHCs anode.