Ultrahigh Pyridinic/Pyrrolic N Enabling N/S Co‐Doped Holey Graphene with Accelerated Kinetics for Alkali‐Ion Batteries

Abstract

AbstractCarbonaceous materials hold great promise for K‐ion batteries due to their low cost, adjustable interlayer spacing, and high electronic conductivity. Nevertheless, the narrow interlayer spacing significantly restricts their potassium storage ability. Herein, hierarchical N, S co‐doped exfoliated holey graphene (NSEHG) with ultrahigh pyridinic/pyrrolic N (90.6 at.%) and large interlayer spacing (0.423 nm) is prepared through micro‐explosion assisted thermal exfoliation of graphene oxide (GO). The underlying mechanism of the micro‐explosive exfoliation of GO is revealed. The NSEHG electrode delivers a remarkable reversible capacity (621 mAh g−1 at 0.05 A g−1), outstanding rate capability (155 mAh g−1 at 10 A g−1), and robust cyclic stability (0.005% decay per cycle after 4400 cycles at 5 A g−1), exceeding most of the previously reported graphene anodes in K‐ion batteries. In addition, the NSEHG electrode exhibits encouraging performances as anodes for Li‐/Na‐ion batteries. Furthermore, the assembled activated carbon||NSEHG potassium‐ion hybrid capacitor can deliver an impressive energy density of 141 Wh kg−1 and stable cycling performance with 96.1% capacitance retention after 4000 cycles at 1 A g−1. This work can offer helpful fundamental insights into design and scalable fabrication of high‐performance graphene anodes for alkali metal ion batteries.