Crystalline‐Amorphous Binary CoS‐Modified VS 2 Hybrid Frameworks as Battery‐Type Electrodes for Long‐Life Supercapatteries

ABSTRACT The rational engineering of CoS‐modified VS 2 (CoVS) hybrid electrodes through a facile solvothermal route facilitates rapid redox kinetics, efficient ion transport, and prolonged cycling stability for supercapattery applications. All‐inclusive structural and surface analyses corroborate the formation of a well‐integrated crystalline‐amorphous CoVS framework with uniform elemental distribution and abundant electroactive sites. These features collectively improve electrolyte accessibility, ion diffusion, and reduce polarization during electrochemical operation. Synergistic coupling between the Co 2+ /Co 3+ and V 4+ /V 5+ redox couples further promotes charge‐transfer kinetics and suppresses electrochemical polarization. As a result, the optimized CoVS (Co:V = 2:1 molar ratio) electrode delivers a specific capacitance of 403.39 F g‐1 (201.69 C g −1 ) at 0.1 A g −1 , also retaining 61% of capacitance at a higher 1 A g −1 , and maintaining 87.11% after 10 000 cycles, which reflects the robust structural integrity of the hybrid electrode framework. Furthermore, the CoVS (2:1)//AC asymmetric device exhibits 125.69 F g −1 at 0.1 A g −1 within a 1.0 V window, achieving an energy density of 17.45 Wh kg −1 at a power density of 618 W kg −1 . The device maintains 82.53% capacitance retention and 99% Coulombic efficiency after 10 000 cycles, highlighting compositional synergy and controlled structural disorder as an effective strategy for high‐rate, durable energy storage.