Chromium Cobaltite Based Ternary Composite as Efficient Electrode Material for Hybrid Supercapacitors with Theoretical Investigation

Abstract

To cater the growing demand of 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 high surface area and excellent cyclic stability of AC, synergistically boost the performance of CrCo2O4. The ternary composite CrCo2O4/AC/PPY exhibited a high 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 cyclic stability with 84.25% capacitive retention after ten thousand cycles. The composite also delivered lower charge transfer resistance (0.36 Ω), which resulted in better charge transfer. A HSC with CrCo2O4/AC/PPY as the positive and MnO2/AC as the negative electrode was fabricated that delivered a high energy density of 97.77 Wh 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 the application in high-performance advanced hybrid SCs.