Chemically bubbled 3D N-doped honeycomb-like carbon nanocage@carbon nanotube-based monolithic electrode for supercapacitor and lithium ion battery

Abstract

Three-dimensional (3D) pyrolytic carbon has risen to prominence as an effective kind of active material or substrate for energy-related applications. However, the poor electrical conductivity and relatively low capacity still remain obstacles for its further use. Herein, we report a smartly designed chemical blowing strategy towards the implantation of highly conductive carbon nanotubes (CNTs) into 3D N-doped honeycomb-like carbon nanocage (NHCN) by introducing an extra carbon source during the Ni(NO3)2-induced polymer blowing process. It is noted that Ni(NO3)2 has dual functions in our work: blowing the polymer and catalyzing the growth of CNTs. More importantly, the residual inactive Ni catalysts in the NHCN@CNT are in-situ converted into active NiS/Ni2P via a post sulfidizing/phosphating treatment rather than being removed. As a proof-of-concept demonstration, the resulted NHCN@CNT (154.4F g−1 at 1 A/g) and NHCN@CNT@Ni2P (1416.8F g−1 at 1 A/g) both perform well as supercapacitor (SC) electrodes. Moreover, the NHCN@CNT@Ni2P also manifests good lithium storage ability (462.8 mAh g−1 at 0.1 A/g). Thus, it is assumed that the intelligently constructed NHCN@CNT in this work hold great potential to be an attractive carbon material for energy storage devices.