Halogen-Bonding Drived Self-Assembly Synthesis of B/N/Cl-Rich Layered 3d Carbon Nanosheet Stacks for Zinc-Ion Hybrid Supercapacitors

Abstract

Cost-efficient fabrication of heteroatom multi-doped and morphology-controllable carbon cathodes with excellent capacity for Zn-ion hybrid supercapacitor (ZICS) is highly desirable but still challenging. Herein, we demonstrate a novel halogen-bonding drived self-assembly strategy to fabricate B/N/Cl-rich layered 3D carbon nanosheet stacks, where chloroethyl amine derivatives (CAH) and ammonium pentaborate (AP) serve as C/Cl/N sources and B-containing 2D template, respectively. The halogen-bonding drives CAH and AP to construct an interconnected 3D network, endowing high B/N/Cl-codoped and layer-by-layer stacked wrinkle carbon nanosheets (ClBNC-850) with hierarchically porous structure. The resultant ClBNC-850 cathode with chlorine doping effect is pioneeringly introduced in ZISC, exampling a cogent model to clarify the cooperative effect of chlorine-induced defects and layer-stacked nanosheets for carbons in ZICS, achieving high capacity (220 mAh g−1 at 1.0 A g−1) and energy density (225 Wh kg−1 at 1122 W kg−1), good flexibility, surpassing the recently reported carbon-based ZICS. Meanwhile, the ex-situ characterizations and theoretical calculations reveal that the chlorine-induced defects engineering can adjust the electronic structures of the B/N-doped carbons, as active centers, enhance accessibility and adsorption-capacity of Zn2+. This approach paves a new way to construct advanced carbon cathodes with high-performance Zn-ions storage at the atom level.

Keywords: Halogen-bonding, Self-assembly, Chlorine doping, Layered carbon nanosheet stacks, Zn-ion hybrid supercapacitor