Dual metal MOF derived Co-Ni/rGO as cathode material with synergetic effect for an asymmetric supercapacitor with enhanced performances

Transition metal oxide/hydroxide possesses high theoretical capacity by inducing faradaic processes. However, it is facing the challenges associated with using individual transition metal oxide/hydroxide as an electrode material for supercapacitors. Specifically, the depletion of the metal upon exposure to the electrolyte during cycling processes leads to poor performance. To address this issue, a novel CoNi alloy, derived from bi-metal organic frameworks (MOFs), intercorporate with rGO nano-sheet was synthesized as an electric conductive network. This Co-Ni/rGO composite exhibited high performances with a specific capacitance of 5229.5 F g−1 at 1 A g−1, and 81.3 % capacitance retention after 1300 charge-discharge cycles at 10 A g−1. Additionally, the composite was also used as a cathode in an asymmetric supercapacitor configuration alongside an rGO aerogel anode, resulting in an energy density of 39.58 and 14.38 W h kg−1 at power densities of 208.3 and 20,833.33 W kg−1. The device showed an 87.4 % capacitance retention after 10,000 cycles at a current density of 10 A g−1, highlighting the potential of this composite for future energy storage applications.