Heterogeneous layered bimetallic hydroxide electrode material for high-rate solid-state supercapacitor

In comparison to aqueous supercapacitors, solid-state supercapacitors demonstrate enhanced energy density and prolonged cycling stability. However, they exhibit suboptimal ion transport rates. The electrochemical impedance of bimetallic hydroxides is significantly lower than that of their monometallic counterparts, while the heterogeneous structure further facilitates the enhancement of the electrochemical reactivity of the electrode materials. Consequently, this study focuses on the synthesis of a two-dimensional heterogeneous layered copper oxide/nickel-cobalt hydroxide (CuO/(Ni, Co)(OH)2). Increased interaction between active sites and electrolyte ions is made possible by the heterogeneous and layered structure, resulting in a solid-state CuO/(Ni, Co)(OH)2// activated carbon supercapacitor displaying good rate performance and maintaining 45 % capacitance even at 20 A g- 1 current density. For the solid-state supercapacitor, at 800 W kg- 1 of power density, energy density can reach 41.6 Wh kg- 1. Meanwhile, even at a power density of 16, 000 W kg-1, the energy density can still reach 18.7 Wh kg-1. This characteristic enables it to have a faster charging and discharging process, which helps meet instant high-energy demand applications.