Electrochemical behavior of Zn–Co layered double hydroxide in supercapacitor with the assistance of theoretical calculation models

A facile hydrothermal method was herein developed to synthesize two-dimensional (2D) zinc–cobalt layered double hydroxides (Zn–Co LDHs). Morphologies and components of 2D Zn–Co LDHs were analyzed by SEM, XPS, and XRD. The Zn–Co LDHs with nanoplates shape showed a wide size distribution from 100–1000 nm and thin thickness from 12 nm to 20 nm. As applied in the supercapacitor electrode, the Zn–Co LDHs possessed a specific capacitance value of 618.2 F/g scanned at 4 A/g. Moreover, the Zn–Co LDHs also performed good charge-discharge reversibility with an efficiency of 114.3% after 100 cycles. In addition, the density functional theory (DFT) calculations supported the dominance of Co in the electrochemical behavior of Zn–Co LDHs.