Mo-doped NiCo-LDH nanoflower derived from ZIF-67 nanosheet arrays for high-performance supercapacitors

Abstract

Layered double hydroxides (LDHs) have gained utmost concern as anode materials for supercapacitors considering their high theoretical specific capacitances, short ion channels and good electrochemical properties. However, their practical application is hindered by low conductivity and limited performance in terms of charge storage. In this study, the researcher successfully synthesized Mo-doped NiCo-LDH nanoflower structures through a straightforward hydrothermal reaction and calcination utilizing lamellar ZIF-67 as a precursor. By adjusting the Mo doping concentration, the researcher was able to maintain the unique multilevel nanoflower-like structure of NiCo-LDH. Furthermore, the inclusion of Mo as a dopant introduced an amorphous phase and effectively modulated the electronic structure of NiCo-LDH, resulting in accelerating charge storage kinetics and reduced volume change. The 0.075 Mo-doped NiCo-LDH exhibited a specific capacitance of 1368.4C g−1 at 1 A g−1, with the capacity retention of 88.4 % at 10 A g−1. Additionally, the assembled asymmetric supercapacitor constructed with 0.075 Mo-doped NiCo-LDH@C//RGO achieved an energy density of 52.2 Wh kg−1 with a power density of 799.3 W kg−1. This study provides valuable insights into the rational doping of Mo elements for the controlled synthesis of supercapacitor electrode materials.