Superior electrochemical performances of highly porous bismuth oxyhalides decorated lemon peel derived activated carbon electrode materials for solid state asymmetric and symmetric supercapattery devices

Abstract

The ever-increasing energy demand and rapid growth of modern industries enforce the scientific community to search for alternative renewable energy resources. To overcome the energy crisis, a hybrid electrochemical energy storage device, namely, supercapattery, is considered a promising green energy source as it combines the merits of supercapacitors and batteries. The present work deals with the electrochemical performance of bismuth oxyhalide/lemon peel-derived activated carbon (BOX-LPDAC, X = bromine, chlorine, or iodine) electrode materials for supercapattery applications. The highly porous sheet-like morphology of the prepared electrode materials promotes more charge storage of electrolytic ions during the electrochemical reaction. Moreover, the BOB-LPDAC (1575.15 C g⁻¹), BOC-LPDAC (1228 C g⁻¹) and BOI-LPDAC (905.37 C g⁻¹) electrodes have high specific capacity than bare BOB (646.75 C g⁻¹), BOC (530.91 C g⁻¹), BOI (409.57 C g⁻¹) and LPDAC (165.19 C g⁻¹) electrodes due to the presence of synergistic battery-type faradaic (BOX) and capacitive-type (LPDAC) charge storage mechanisms. The fabricated solid-state symmetric supercapattery (BOB-LPDAC‖BOB-LPDAC) (SSC) device could deliver an energy density of 172.06 Wh kg⁻¹ than the asymmetric supercapattery (BOB-LPDAC‖LPDAC) (ASC) device (47.1 Wh kg⁻¹). Compared to the ASC device, the SSC device could power a 2 V red LED for 555 s and a 3.7 V electric motor fan for 122 s. Hence, the prepared BOB-LPDAC nanocomposite may serve as an excellent electrode material for solid-state symmetric supercapattery applications.