Understanding the Diffusion‐Dominated Properties of MOF‐Derived Ni–Co–Se/C on CuO Scaffold Electrode using Experimental and First Principle Study

Abstract Batteries and supercapacitors continue to be one of the most researched topics in the class of energy storage devices. The continuous development of battery and supercapacitor cell components has shown promising development throughout the years—from slabs of pure metal to porous and tailored structures of metal‐based active materials. In this direction, metal–organic frameworks (MOFs) serve great advantages in improving the properties and structure of the derived metal‐based active materials. This research provides a novel electrode material, Ni–Co–Se/C@CuO, derived from Ni–Co‐MOF integrated with pre‐oxidized Cu mesh. The superior electrochemical performance of Ni–Co–Se/C@CuO over Ni–Co‐MOF@CuO is evident through its higher specific capacity, lower resistivity, richer redox activity, and more favorable diffusion‐dominated storage mechanism. When assembled as a hybrid supercapacitor (HSC), the hybrid device using rGO and Ni–Co–Se/C@CuO as electrodes exhibits a high energy density of 42 W h kg −1 at a power density of 2 kW kg −1 , and maintains its capacity retention even after 20 000 cycles. The improved capacity performance is also evaluated using first‐principle investigations, revealing that the unique and preserved heterostructure of Ni–Co–Se/C@CuO portrays enhanced metallic properties. Such evaluation of novel electrodes with superior properties may benefit next‐generation electrodes for supercapacitor devices.