Design and Performance Evaluation of Hierarchical ZnCo2S4@PANI Core-Shell Nanorod Arrays for High-Efficiency Supercapacitor Applications

Ternary transition metal sulfides (TMS) have gained significant attention due to their excellent energy and power density as Faradaic electrode materials to be utilized in supercapacitors (SCs). Among various conducting polymers, polyaniline (PANI) has rapidly evolved as a valuable pseudo-capacitor material. Though it deprived cycling stability due to instability in structural transformation, which is the major obstacle to its practical level utilization in energy related applications. Herein, the synthesis of an efficient and reliable ZnCo2S4@PANI nonorod arrays (NRAs) anode with structure-to-performance hierarchical morphology is designed to achieve excellent performance. Heterostructured, extremely porous ZnCo2S4 nanorods have acted as a conductive core, which has provided the strain-buffer-support, along with nanoscaled PANI layer to act as an electrochemical active counterpart, and has demonstrated outstanding specific capacitance while retaining the remarkable cyclic performance and rate capability. Implementing the perfectly uniform and compactly coated PANI, the synthesized anode has demonstrated a high specific capacitance of ∼815 F g-1 at a current density of 1 A g-1 and exceptional ∼91% capacitance retention even after 4000 cycles at high 2 A g-1 current density. Such outcomes are much superior to the most reported electrochemical performances of PANI-related pseudo-capacitors in the literature. The enhanced electrochemical properties of the as synthesized ZnCo2S4@PANI NRAs anode demonstrate the ability of the stable componential structure as a hybrid electrode design to provide a new direction for researchers to utilize such porous framework as an operative support for proficient energy storage devices.