One-pot synthesis of sandwich-like reduced graphene oxide@CoNiAl layered double hydroxide with excellent pseudocapacitive properties

Abstract

Layered double hydroxide is one kind of promising material for pseudocapacitors. However, the poor conductivity limits their applications. One possible way to resolve this problem is to mix them with conductive carbon materials. In this work, we developed a one-pot strategy to synthesize sandwich-like nanocomposites with cobalt nickel aluminum layered double hydroxide growth on both sides of different amounts of reduced graphene oxide (RGO(X)@CoNiAl-LDH, X represents the amount of RGO). Such a unique structure is very beneficial for enhancing the conductivity and electrochemical performance. When used as an electrode material for supercapacitors, RGO(25)@CoNiAl-LDH exhibited the best specific capacitance of 1866 F g⁻¹ at a current density of 1 A g⁻¹ and 1360 F g⁻¹ at 10 A g⁻¹, respectively. Furthermore, they displayed excellent cycling performances without an obvious capacitance decrease after 5000 cycles. Such a simple synthesis method, high specific capacitance, rate capability and exceptional cycling stability of these composites offer great promise in energy storage device applications.