Heterostructured 3D-Co-MOF@CoO/Ni‖3D-C-Fe4N@NiCu/SS hybrids as high-performance electrode materials for efficient hybrid supercapacitor

Designing of 3D heterostructured hybrid materials are effective step, in the pursuit of attaining higher electrochemical performance compared to their pristine metal/metal oxide counterparts, owing to the enlarged active area of electrode-electrolyte interaction, and fast ion transportation path. In this regard, binder-free heterostructured electrodes, 3D-Co-MOF@CoO/Ni (positive) and 3D-C-Fe4N@NiCu/SS (negative) are fabricated to construct a hybrid supercapacitor (HSC). This core-shell structured positive electrode revealed better electrochemical performance (592.8 mC/cm2 at 2 mA/cm2) than bare CoO/Ni, which is nearly twice as good. Meanwhile, the hierarchical microporous 3D-C-Fe4N@NiCu/SS electrode achieved a broad potential of 0 to − 1 V with a maximum areal capacity of 852 mC/cm2 at 2 mA/cm2 and 72 % stability over 10000 GCD cycles. The 3D heterostructured morphologies of the electrodes endowed the 3D-Co-MOF@CoO/Ni‖3D-C-Fe4N@NiCu/SS HSC with a high volumetric energy value of 2.305 mWh/cm3 with a volumetric power of 325 mW/cm3. The unique architecture and engineering strategies adopted in this research work can pave the way to attain desired electrochemical output in the future.