Carbon-Induced Generation of Hierarchical Structured\nNi_0.75Co_0.25(CO₃)_0.125(OH)₂ for Enhanced Supercapacitor Performance

Abstract

Hierarchical\nnanostructures with heteroatom doping have been considered as an important\ncomponent in electrode materials for advanced supercapacitors. Herein, with\nthe aid of C, N, and S codoped Ni_0.75Co_0.25(CO₃)_0.125(OH)₂/C (NSH) with a hierarchical\nstructure was synthesized through a facile one-step hydrothermal method.\nNotably, it is the first report on a carbon precursor as a structure\ninducer for designing a three-dimensional (3D) carnation-like hierarchical\nstructure. Thanks to the carbon induction effect and the introduction\nof N/S dopants, the obtained NSH with a 3D architecture exhibits superior\nperformances as electrode materials for supercapacitors. For example,\nNSH offers a high specific capacity of 277.3 mAh/g at 0.5 A/g. Moreover,\nthe assembled NSH//reduced graphene oxide hydrogel-based hybrid supercapacitor\nexhibits high energy densities of 44.4 and 11.7 Wh/kg at power densities\nof 460 W/kg and 9.8 kW/kg, respectively. This result opens up opportunities\nfor carbon-induced methods to control the morphology and structure\nof other similar materials.