Influence of different Ni:Fe molar ratios on the properties of NiFe-LDH as electrode materials for supercapacitor applications

Abstract

Layered double hydroxides (LDH) are being explored as a promising electrode material for supercapacitors due to their cost-effectiveness, high reactivity, and environmental friendliness. Nowadays, considerable efforts about LDH as electrode material have focus on the composition of different bimetals or trimetals, and few studies on the impact of the different bimetal ratio. In this study, NiFe-LDH materials with different proportions were synthesized by one-step hydrothermal method. The results show that the content of Ni and Fe in NiFe-LDH has a certain effect on the electrochemical performance of the electrode. In particular, the Ni5Fe1-LDH electrode exhibits outstanding performance in terms of both specific capacity and energy density, even than some composite materials based on NiFe-LDH. Specifically, the Ni5Fe1-LDH electrode demonstrates a specific capacity of 139.83 mAh g−1at 0.5 A g−1, maintaining a cycle efficiency of 66.36 % after 3000 cycles. Furthermore, the Ni5Fe1-LDH//AC demonstrates a high energy density of 35.85 Wh kg−1 at a power density of 800 W kg−1.