Nickel-cobalt oxide nanocages derived from cobalt-organic frameworks as electrode materials for electrochemical energy storage with redox electrolyte

摘要: Abstract Nickel-cobalt (Ni-Co) oxide nanocages were synthesized by etching the cobalt-based metal-organic framework (Co-MOF) with nickel nitrate in an isopropyl alcohol solution. The dodecahedral Co-MOF (300 nm size) was composed of micropores, while Ni-Co gained additional mesopores and macropores. Both electrodes KOH behaved more like nondiffusion-controlled pseudocapacitor through surface adsorption/desorption a concomitant faradaic charge-transfer reaction. In presence ferrocyanide/ferricyanide redox electrolyte, both nondiffusion- diffusion-controlled currents contributed equally to current response electrode at lower scan rates. Nondiffusion-limited processes governed charge-storage behavior faster electrolyte showed high specific capacities 810 496 C g −1 charge/discharge densities 10 50 A g , respectively, much greater than that without (384 348 C g ). highly porous could provide large electrolyte/electrode interface store charges short pathways expedite transport electron ion, showing noticeable increase its electrochemical performance compared electrode.