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” NiCo ₂O ₄-CNT-c-PEGm//rGO-PANI (NiCo//G-PANI) with high capacity and ultralong lifetime were fabricated and evaluated. The three-dimensional hierarchical flower-like NiCo ₂O ₄ -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 NiCo ₂O ₄-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.