W doping and surface reconstruction induced defects enabled high specific capacity of NiFeCoW-layered double hydroxide

Abstract

Defect engineering has been regarded as an effective strategy to enhance the electrochemical capacitance of supercapacitors. In this work, we report an effective strategy to promote the formation of defects along with the surface reconstruction of NiFeCo-layered double hydroxide (LDH) by W doping and a successive in-situ electrochemical activation process. Our results reveal that the surface of NiFeCoW-LDH is reconstructed at high potential, which promotes the generation of vacancy and dislocation in NiFeCoW-LDH. The electrochemical activated NiFeCoW-LDH exhibits a capacitance as high as 12.35 F cm−2 at the current density of 5 mA cm−2 in 1 mol L−1 KOH. The defects and the surface nanoneedles structure synergistically contribute to the enhanced electrochemical performance. This work proposes a promising strategy for the design of rich defective electrodes along with surface reconstruction.