A chromium cobaltite based ternary composite as an efficient electrode material for hybrid supercapacitors with...

To cater to the growing demand for advanced energy storage devices, the development of efficient electrode materials with brilliant electrochemical response is highly required. Battery-like materials have gained wide research attention as effective electrode materials for hybrid supercapacitors (HSCs). In this account, chromium cobaltite (CrCo₂O₄) has been synthesized via a facile hydrothermal route. The structural and electronic properties of CrCo₂O₄ have been investigated using DFT. Activated carbon (AC) and polypyrrole (PPY) have been introduced to hybridize with CrCo₂O₄ to enhance its electrochemical performance. The high conductivity of PPY, along with the high surface area and excellent cycling stability of AC, synergistically boosts the performance of CrCo₂O₄. The ternary composite CrCo₂O₄/AC/PPY exhibited a higher capacitance of 991.25 F g^-1 than the pristine CrCo₂O₄ (301.53 F g^-1) at 5 mV s^-1. The composite also displayed high cycling stability with 84.25% capacitive retention after ten thousand cycles. The composite also delivered a lower charge transfer resistance (0.36 Ω), which resulted in better charge transfer. A HSC with CrCo₂O₄/AC/PPY as the positive electrode and MnO₂/AC as the negative electrode was fabricated that delivered a high energy density of 97.77 W h kg^-1 and power of 1.6 kW kg^-1. A high capacitive retention of 76.75% was observed for ten thousand cycles. The practicality of the prepared material was tested by connecting three hybrid cells in series to illuminate a panel of 57 LEDs. The panel was able to glow for 51 minutes. The outstanding performance of the composite reveals the excellent possibility for application in high-performance advanced hybrid SCs.