Edge Porous NiO Hexagonal Nanosheets as Electrode Materials for Supercapacitors

Abstract

Utilization of two-dimensional materials containing high specific surface area and suitable pore size for electrode materials in supercapacitors is proving to be a promising strategy for energy storage and energy conversion. Transition metal oxides with high natural abundance as well as excellent electrochemical properties have been investigated. NiO materials have been widely used as pseudocapacitors in aqueous electrolytes. However, different synthesis methods can markedly affect the electrochemical performance and lifetime of the materials. In this work, the Ni(OH) 2 precursors were etched with ammonia at high temperature and pressure using a hydrothermal approach, which resulted in a material with a suitable pore size and a large number of active sites on the edge part. Electrochemical tests and characterization revealed the superiority of the materials prepared by this synthetic method as pseudocapacitors electrode materials as well as a new synthetic idea for commercial production.