Reverse microemulsion synthesis of nickel-cobalt hexacyanoferrate/reduced graphene oxide nanocomposites for high-performance supercapacitors and sodium ion batteries

摘要

Graphical abstractThe Ni-CoHCF/rGO nanocomposite was synthesized via a microemulsion method, which exhibits outstanding electrochemical performance for supercapacitors and sodium ion batteries.Display OmittedHighlights•The Ni-CoHCF/rGO nanocomposite has been synthesized using microemulsion method.•The agglomeration of pure Ni-CoHCF nanoparticles can be prevented using rGO.•Surface wettability of the Ni-CoHCF/rGO has been largely improved.•The Ni-CoHCF/rGO nanocomposite exhibits highly enhanced electrochemical performance.AbstractPrussian blue analogues with tunable open channels are of fundamental and technological importance for energy storage systems. Herein, a novel facile synthesis of nickel-cobalt hexacyanoferrate/reduced graphene oxide (denoted as Ni-CoHCF/rGO) nanocomposite is realized by a reverse microemulsion method. The very fine Ni-CoHCF nanoparticles (10–20 nm) are homogeneously anchored on the surface of reduced graphene oxide by electrostatic adsorption and reduced graphene oxide is well-separated by Ni-CoHCF particles. Benefiting from the combined advantages of this structure, the Ni-. It CoHCF/rGO nanocomposite can be used as electrodes for both supercapacitors and sodium ion batteries exhibits excellent pseudocapacitve performance in terms of high specific capacitance of 466 F g−1at 0.2 A g−1and 350 F g−1at 10 A g−1, along with high cycling stabilities. As a cathode material for sodium ion batteries, it also demonstrates a high reversible capacity of 118 mAh g−1at 0.1 A g−1, good rate capability, and superior cycling stability. These results suggest its potential as an efficient electrode for high-performance energy storage and renewable delivery devices.