One-step firmly anchor graphdiyne on NiCo-LDHs as supercapacitor electrode for considerable durability

Abstract

Nickel-based hydrotalcite has been widely used in supercapacitor electrodes due to its multivalence. Unfortunately, the poor stability and low conductivity for charge transfer impede further development in the field of energy storage. Herein, the graphdiyne (GDY) nanosheets were added to the growth process of nickel cobalt hydrotalcite (NiCo-LDHs), which to make up for these two deficiencies of NiCo-LDHs. Due to the strong combination of NiCo-LDHs and GDY, the specific capacitance of the obtained NiCo-LDHs@GDY reaches 1284 F g−1 (1.5 times than NiCo-LDHs) under a current density of 1 A g−1 with a rate performance of 72.08 % under the current density of 20 A g−1. In addition, the NiCo-LDHs@GDY//AC Asymmetric Supercapacitor (ASC) assembled with activated carbon demonstrates an energy density of 23.06 Wh kg−1 at a high power density of 3108.96 W kg−1. Rejoicingly, the charge storage capacity remains at 89.53 % after 5200 charge-discharge cycles under the current density of 10 A g−1. These outcomes show that the NiCo-LDHs@GDY electrode material has remarkable application potential and can achieve better characteristics for high-performance supercapacitors in energy storage applications.