A two-dimensional nickel-doped bismuth-layered double hydroxide structure as a bifunctional efficient electrode material for symmetric supercapacitors.

There has been an increasing demand for the development of low-cost and environmentally friendly two-dimensional (2D) heterostructure materials for energy storage and conversion systems due to their superior chemical and physical properties. This study reports a direct and feasible hydrothermal approach to synthesize nickel-doped bismuth-layered double hydroxide as a 2D heterostructure bifunctional electrode material (acts as anode and cathode) for symmetric supercapacitors. The designed electrode can work within a wide and efficient operating potential window, delivering a specific capacity of 450C g-1 at 1 A g-1 and an outstanding cycling performance with 93% capacity retention being stable after 3000 cycles. Furthermore, the assembled symmetric supercapacitor delivers significant specific energy of 43 Wh kg- 1 at a specific power of 725 W kg -1. These results are among the superior symmetric supercapacitors reported previously, indicating a potential strategy for designing efficient symmetric supercapacitors for real-life applications.

Automated summary

This study reports a hydrothermal approach to synthesize nickel-doped bismuth-layered double hydroxide as a 2D heterostructure bifunctional electrode material for symmetric supercapacitors. The designed electrode exhibits a wide and efficient operating potential window, high specific capacity, outstanding cycling performance, and significant specific energy. These results suggest a potential strategy for designing efficient symmetric supercapacitors.