Fabrication of (MnFeNiCo)3O4/rGO/PANI-based Symmetric Supercapacitor with High Electrochemical Performance and Long-term Stability

Abstract

Supercapacitors (SCs) have emerged as the most promising devices for electrochemical storage and conversion applications. They can act as a bridge between existing devices and demonstrate intrinsic properties of high energy density and longer cycle life. The electrochemical performance of the SC device depends on the electrode's active material; therefore, considerable effort is being devoted to developing hybrid composites. With high surface area and a robust structural framework, carbon-based materials like reduced graphene oxide (rGO) have potential for SC devices but suffer from limited long-term performance [1]. Multiple redox transitions of metal ions and the high-rate performance of transition metal oxides (TMOs) also make them unique for storage applications [2]. Multimetallic oxides (MnFeCoO4, MnFeNiO4, MnFeNiCoO4) offer numerous redox sites for faradic reactions, thereby contributing to charge storage. They often suffer from poor conductivity and low power density. Conducting polymers such as polyaniline (PANI), with tunable oxidation states and facile synthesis, also exhibit distinct energy storage and conversion capabilities [3]. Due to continuous charging/discharging, they show degradation of the long polymeric chains. To address such issues, our work demonstrates a synergistic approach to developing a hybrid ternary composite (MnFeNiCo)3O4/rGO/PANI-based device with enhanced charge-storage capability, outperforming individual devices. [4]. The fabricated symmetric device exhibited a specific capacitance of ~362 F/g and an energy density of 50 Wh/kg. It also exhibited 95% retention capacity after 6000 cycles. With such characteristics, the synthesized novel composite shows potential for SC application.