Double ion-buffering reservoirs of advanced NiCo//G-PANI asymmetric supercapacitors with high performance

Asymmetric supercapacitors (ASCs) have been designed due to their lower cost effectiveness, better safety, long cycle life, and high energy/power density. Herein, the ASC of double "ion-buffering reservoirs " NiCo2O4-CNT-c-PEGm//rGO-PANI (NiCo//G-PANI) with high capacity and ultralong lifetime were fabricated and evaluated. The three-dimensional hierarchical flower-like NiCo2O4-CNT-c-PEGm microspheres were prepared via solvothermal method. In these composites, the incorporated CNTs were modified with methoxypolyethylene glycol (mPEG) polymer by Cu(I)-catalyzed click chemistry. The NiCo2O4-CNT-c-PEGm composites with typical honeycomb-like "ion-buffering reservoir " structures exhibited the specific capacity of 191.3 mAh g-1 at 0.5 A g-1. Moreover, the rGO-PANI composites with hierarchical interconnected porous network structures as "ion-buffering reservoir " were prepared via in situ polymerization and chemical reduction. Further, the rGO-PANI electrode materials could achieve the specific capacity of 81.5 mAh g(-1) at 1 A g(-1). Owing to such excellent attributes, the as-assembled ASC NiCo//G-PANI exhibit the specific capacity of 84.7 mAh g(-1) at 1 A g(-1) and high energy density of 67.7 Wh Kg(-1) at a power density of 800 W Kg(-1) for the potential applications in electric energy storage technologies. As a result, this study promotes an innovative strategy to synthesize the metal oxides modified with carbon materials as positive electrode materials to assemble the new type of ASCs.(C) 2022 Elsevier B.V. All rights reserved.