High-performance asymmetric supercapacitors of advanced double ion-buffering reservoirs based on battery-type hierarchical flower-like Co3O4-GC microspheres and 3D holey graphene aerogels

摘要: Abstract We have prepared 2D macromolecular brushes of G>N-PEGm nanosheets and CNT>N-PEGm from the Graphene CNTs with methoxypolyethylene glycol (mPEG) via Nitrene Chemistry, respectively. Owing to a typical solvothermal method, hierarchical flower-like spheres Co3O4-G>N-PEGm-CNT>N-PEGm (Co3O4-GC) ternary composites been synthetized, which present honeycomb-like structures as “ion-buffering reservoir” substantial ion-diffusion channels in ultrathin 2–4 nm Co3O4 nanosheets. And battery-type positive electrode materials, high capacity Co3O4-GC can be calculated up 173.3 mAh g−1 at 0.5 A g−1 (the specific capacitance achieved 1783 F g−1). On other hand, 3D holey reduced graphene oxide carboxylic CNT aerogels (HRGO CNTc, denoted HRGC) formed acid-modified CNTc are summarized 282.3 Fg−1 (78.4 mAh g−1) 0.5 A g−1, demonstrating excellent long cycling performance. The advanced double reservoirs” asymmetric supercapacitors Co3O4-GC//3D HRGC energy devices further fabricated based on negative electrode, meanwhile electrochemical performance also exhibit 42.6 Wh kg−1 power densities 775 W kg−1 81.1% maintained after 10,000 cycles for energy-storage energy-conversion potential application.